Vol 28, No 3 (2025)

Traditional literature review and the standard methods of data analysis in immunology is time-consuming and does not allow rapid solution of large-scale and complex research problems. Artificial intelligence can assist in addressing this issue by automating the processes of search and evaluation of relevant information. The aim of this study was to determine the potential of artificial intelligence in immunological research, based on the automated collection of literature data and analysis of digital information. The theoretical aspect of the study was based on the analysis of materials from PubMed, Scopus, ResearchGate databases covering the years 2000-2025. The practical approach was conducted via comparative analysis of previously published data and conclusions obtained by means of artificial intelligence technologies, e.g., by GPT v.4.0 models. It was found that artificial intelligence technologies may be useful in conducting literature reviews in immunology, including compilation of findings, generation of graphical presentations, as well as visualization of new signaling pathways, cellular interactions, and disease-related factors. In addition to the text analysis, artificial intelligence may be applied to statistical processing and digital data analysis, such as detection of regularities, solution of forecasting issues, design of models. A comparison of previously studied data with the results obtained using GPT v.4.0 revealed several limitations of different chatbot models, including the dependence of responses on the style of query formulation, excessively generalized information synthesis, limited text output (up to 1,000 words), plagiarism risks, difficulties in generating figures, diagrams, and tables, presentation of comprehensive information predominantly in English, and spontaneous creation of non-existent references to the literature sources. Conclusions: 1. Artificial intelligence may sufficiently change immunological research, allowing for a more effective literature reviewing and deeper data analysis, however, requiring expert supervision at the initial stages. 2. Upon development of artificial intelligence technologies, they will become an integral part of the immunologist’s toolkit.

Melatonin (N-acetyl-5-methoxytryptamine) is the primary hormone of the pineal gland. However its synthesis also occurs in various extra-pineal tissues, including brain, retina, retinal pigment epithelium, gastrointestinal tract, bone marrow, thymus, lymphocytes, and skin. Melatonin is an amphiphilic indole derivative that combines hydrophilic (methyl and amide groups) and hydrophobic (indole core) molecular domains. Due to its unique structure, which ensures high bioavailability, and presence of hormone and enzymatic mechanisms for its synthesis in various organs and tissues, melatonin is involved in regulating numerous physiological processes, thus highlighting its significant role in maintaining systemic homeostasis. The pleiotropic effects of melatonin are due to a combination of its direct molecular interactions and mediated regulatory mechanisms. On the one hand, melatonin is a powerful endogenous antioxidant capable of directly neutralizing reactive oxygen and nitrogen species. On the other hand, its physiological effects are realized through binding to specific protein targets, as well as via secondary mechanisms, including activation of antioxidant defense, metabolic, and epigenetic modulation. Interaction of this hormone with numerous extracellular and intracellular molecular targets is of particular interest, with binding affinity varying across a wide range of concentrations. Numerous studies over recent decades have identified about twenty distinct protein targets of melatonin, spanning a broad spectrum of functional categories – from well-characterized receptors (both membrane-bound and nuclear) to some non-canonical targets. The latter include: enzymes (quinone reductase-2, matrix metalloproteinase-9, protein phosphatase-2A, pepsin), ion channels, transport and structural proteins (glucose transporter GLUT1, oligopeptide transporters PEPT1 and PEPT2, serum albumin, tubulin), calcium-binding proteins (calmodulin, protein kinase C, calreticulin). Recently, the search for melatonin targets is continued. It is suggested that, in addition to its mediated effects, the hormone may directly modulate activity of P-glycoprotein, a membrane drug resistance protein and NAD+-dependent deacetylases – sirtuins SIRT1 and SIRT3. Studying the melatonin targets is crucial for analyzing its pharmacodynamic effects. A search for new targets opens perspectives for understanding its non-circadian functions of this hormone, e.g., neuroprotection, anticancer effects, and metabolic modulation.

Macrophages have great significance in immune response, being important participants in innate immunity. They are capable of both directly and indirectly fighting pathogens by regulating the surrounding cells via biologically active substances. In response to various stimuli, macrophages may switch from basal step to a pro- or anti-inflammatory state, polarizing into the M1 or M2 phenotype. M1 macrophages have a pro-inflammatory phenotype, being activated under the influence of cell wall lipopolysaccharide from Gram-negative bacteria, or some pro-inflammatory cytokines. M2 macrophages acquire an anti-inflammatory phenotype upon activation of some immune response receptors (Fcγ and TLR), cytokines IL-4, IL-13, IL-10 and other stimuli. Macrophages are also capable of alleviating their immune response depending on the duration and/or frequency of inflammatory signal, thus developing immune tolerance effect. Of particular importance is tolerance to bacterial lipopolysaccharide, when the macrophages acquire refractoriness to repeated stimulation compared to the primary one, producing less cytokines and chemokines. The aim of our study was to assess the role of cytokines and chemokines CCL2, CXCL1, CXCL9, CXCL12, IL-1b, IL-4, IL-6, IL-7, IL-8, IL- 15, IL-22, TNFα on immune response of macrophages to lipopolysaccharide and emergence of immune tolerance. Primary monocytes were obtained from venous blood of healthy donors. E. coli lipopolysaccharide (LPS) was used to stimulate monocytes and differentiated macrophages. We have shown that pre-treatment of primary human macrophages with recombinant cytokines IL-4 and TNFα enhances the inflammatory response to repeated stimulation with lipopolysaccharide, i.e. weakens the development of tolerance. This effect was expressed as increased production of cytokines (TNFα, IL-6, IL-10) and IL-8 chemokine in presence of recombinant IL-4, and TNFα production with recombinant TNFα. At the same time, recombinant IL-4 was also able to enhance the inflammatory signal of macrophages upon a single LPS stimulation, thus increasing the TNFα and IL-8 secretion. We have shown that some cytokines may affect the tolerance of macrophages to LPS. This phenomenon may involve transition of macrophages from one polarization state to another, or to an intermediate step. Modulation of macrophage phenotype and its immune response opens the way to the development of new therapeutic approaches to inflammatory diseases, where tolerance to lipopolysaccharide plays a significant role in pathogenesis, such as sepsis and atherosclerosis.

This study aimed to investigate the immunotropic effects of a pharmaceutical composition based on a probiotic strain metabolites, and plant components of various origin using an in vitro model of human monocyte culture. The authors propose a mixture of exometabolites from Saccharomyces boulardii (S. boulardii) as the basis of all suggested formulations aimed at regeneration of human epithelial cells. The compositions included St. John’s wort extract and coriander oil. The effectiveness of these pharmaceutical compositions was evaluated using monocytes isolated from adult donors. Mononuclear cells (MNCs) were isolated by gradient centrifugation. The monocytes were seeded into 24-well plates, co-cultured with the studied compositions (experimental samples) and without compositions (controls). Monoclonal antibodies were used to identify cell markers of monocyte/macrophage lineage. Phenotypic analysis of monocytes was performed using a CytoFLEX flow cytometer. The M2 phenotype was characterized using CD204, CD163, and CD206 antibodies, whereas the M1 phenotype was assessed using CD80 and CD86 antibodies. It was proven that co-cultivation with St. John’s wort extract induced cultured monocytes to acquire the M1 phenotype, while a significantly increased expression of all surface markers for TLR4, CD80, and CD86 was observed. In contrast, the coriander extract (mixture #1) significantly inhibited the expression of M2 phenotype markers compared with unstimulated cells. The percentage of M2 monocytes (CD204+, CD206+, and CD163+ phenotypes) was increased after co-cultivation with both oil and after co-cultivation with S. boulardii metabolites for all the studied markers. Exposure to coriander oil and mixture No. 1 significantly reduced the gene expression of all M1 markers, i.e. TLR4, CD80, CD86. The reducing effect of M1 marker expression persisted after addition of S. boulardii metabolites only for TLR4 and CD86 compared with the control. A subpopulation of monocytes with TLR4+, CD204+, CD206+, CD163+ phenotype, coexpressing the M1 and M2 polarization markers was detected during co-cultivation with both mixtures #2 and #3. The percentage of hybrid TLR4 +M2 monocytes was significantly higher in mixture 2 compared with mixture 3 (p < 0.001 and p < 0.05, respectively). Hence, the mixtures under study cause M1/M2 monocyte polarization depending on the composition, thus recommending its potential usage in cosmetology and medical practice, depending on etiology of the disease.

The publication is devoted to very topical issues in the field of immunopharmacology on the creation of new bio compounds from the group of probiotics and biologically active substances produced by them, namely, the development of a new hepatoprotective pharmacological drug with an immunomodulatory effect. Today, in the field of modern pharmacology and biotechnology, microorganisms of the hay bacillus are promising and in-demand producers for obtaining a new class of bio compounds – metabiotics. One of the key advantages is the absence of cells in their composition, which significantly reduces the immune burden on the macroorganism while maintaining its functional and biological potential. At the same time, the issues of the development, creation and construction of medical immunobiological preparations of metabiotics for use in the pharmaceutical, medical and biotechnological fields remain very relevant and far unresolved. The metabolites synthesized by hay bacillus, namely Bacillus subtilis strains B-23xx, B-99xx1 and B-99xx2, were used in the work. In our earlier studies, the safety was demonstrated and a significant hepatoprotective effect of the above strains was established, which can be successfully used to construct modern hepatopicts with hepatoprotective properties. At the same time, the unexplored possibility of systemic immunotropic action of these metabiotic compounds remains very relevant. It is important to note that the simultaneous use of three complexes of biologically active substances will provide a significant potentiating immunotropic pharmacological effect. The aim of the study was to experimentally study the immunotropic effect of a new bio compound on cellular immunity using a model of acute toxic hepatitis in laboratory animals. Acute toxic liver damage was reproduced in white laboratory rats by single oral administration of a hepatotropic poison, carbon tetrachloride. The new bio compound was administered intragastrically in the form of a suspension. In the experiment, such indicators as quantitative determination of lymphocytes and antibody-forming cells, determination of phagocytic activity and metabolic activity of peripheral blood neutrophils were evaluated. As a result of the performed studies, it was found that the proposed hepatoprotective bio compounds also have an immunomodulatory effect.

The ability of uropathogenic Escherichia coli (UPEC) to form biofilms is one of the factors causing recurrent urinary tract infections. Myeloperoxidase and cathepsin G of phagocytic cells contribute to antimicrobial protection during inflammation. The existence of cross-reactions between UPEC bacteria, extracellular matrix of biofilms and effector immune cells also cannot be excluded. The aim of our study was to evaluate the secretion of myeloperoxidase and cathepsin G by neutrophils and mononuclear cells of human peripheral blood upon their interaction with bacteria from biofilms, and supernatants of reference cultures and clinical UPEC isolates. Neutrophils and mononuclear cells of peripheral blood of healthy men (n = 6) were isolated in a double Ficoll-Urografin gradient (1.077 g/mL and 1.112 g/mL). The reference DL82 strain of E. coli (fimH, papC, papGII, sfa, hlyA, usp, fyuA, iucD, iroCD, iroN), and the E. coli R44 clinical isolate (fimH) (10⁶ cell/mL) were grown in 96-well polystyrene plates on LB medium for 24 h. The biofilm supernatants were sterilized by filtration (0.22 μM). Bacterial cells were released from the biofilm by sonication. Neutrophils were cultured with biofilm bacteria or their supernatants for 1 h, then centrifuged at 400 g, the supernatant was collected and frozen at -20 °C. MPO and cathepsin G activity was assessed using O-phenylenediamine dihydrochloride and N-benzoyl-L-tyrosine ethyl ester, respectively, by optical density measured in supernatants of neutrophil and mononuclear cell cultures. Statistical processing was performed using Excel software. It was shown that MPO secretion by neutrophils increased upon interaction with E. coli DL82 biofilm supernatants, in contrast to E. coli R44 supernatants. E. coli DL82 and E. coli R44 cells of biofilm did not affect MPO secretion. MPO secretion by human peripheral blood mononuclear cells remained at the control level when exposed to UPEC cells and supernatants. Contact of neutrophils with bacteria and supernatants of the E. coli R44 strain led to a decrease in the concentration of cathepsin G in the medium compared to the control. Exometabolites of UPEC bacterial biofilms seem to provide a more significant impact on neutrophil secretory activity than the bacteria per se.

Development of posttraumatic stress disorder in combatants proceeds via occurence of systemic maladaptive allostatic reactions. It is accompanied by disorders at the somatic and mental levels, based on recurrent experiences of past psychotraumatic events, with unexplained anxiety, anger, guilt, cognitive disorders, psychosomatic astheno-vegetative manifestations. Our objective was to study neurotransmitter metabolism and proinflammatory cytokines in posttraumatic stress disorder in veterans of modern wars. The study included 45 veterans of a special military operation in Ukraine with a confirmed diagnosis of PTSD. The comparison group consisted of 25 veterans of 2^nd Chechen military campaign. The control group included 20 healthy servicemen who did not take part in hostilities. The levels of neurotransmitter metabolic components in blood were determined using test systems from Cloud-Clone Corp. (China); kynurenine levels (ng/mL) were measured by test systems from Immunodiagnostic AG (Germany). IL-1β concentration (pg/mL) was assayed with Luminex Magpix 100 immunoanalyzer (USA). Data comparison was performed using SPSS program. In PTSD group, the concentration of blood serotonin, tryptophan and kynurenine was significantly decreased in veterans of Special Military Operation (SMO), along with increase in serotonin transporter and IL-1β levels. Among veterans of the 2^nd Chechen campaign, a decrease in serotonin and an increase in serotonin transporter were noted if compared with reference group, along with clinical manifestations of maladaptation which manifested with asthenovegetative and somatoform disorders. Discussion: serotonin deficiency is a key factor in development of anxiety, depression, affective disorders in combatants with PTSD. Serotonin concentration in stress-induced disorders decreases due to tryptophan deficiency and its inactivation by the transporter in synaptic space. Activation of meta-inflammatory CNS reactions leads to decreased kynurenine level, induction of neurotoxic reactions due to factors causing apoptosis of astroglia, neurons and oxidative cellular stress. Development of stress-induced pathology in veterans of modern wars is accompanied by changing contents of neurotransmitter metabolic products which occur in presence of a proinflammatory blood profile.

Usage of herbal remedies may present a tool limiting toxicity of methotrexate (MTX). The herbal products are characterized by availability, safety, high biological activity, and very low toxicity. One should highlight the meadow clover and common chicory among medicinal plants containing a variety of biologically active polyphenolic substances, possessing antioxidant, anti-inflammatory, immunocorrective and other favorable properties. Phytoextracts obtained from these plants may be used in order to protect against immunosuppressive effects of MTX and enhance its anti-inflammatory properties without inducing MTX toxicity. At the same time, it should be noted that information on the mechanisms of anti-inflammatory activity of individual phytoextracts is multidirectional. The aim of our work was to evaluate the effect of clover and chicory phytoextracts on secretion of proinflammatory cytokines TNFα, IL-6 and IL-17 by human peripheral blood mononuclear cells under MTX-induced immunosuppression. Dry extracts from clover grass and chicory grass were obtained by percolation with ethyl alcohol. The production of cytokines TNFα, IL-6 and IL-17 in the supernatants of unstimulated and concanavalin A (Con A)- stimulated human peripheral blood mononuclear cell cultures was assessed using the enzyme immunoassay method. Evaluation of immunoregulatory activity of dry extracts from clover and chicory grass, as well as their combinations with MTX using the in vitro model of human peripheral blood mononuclear cells showed that the phytoextracts suppressed the production of proinflammatory cytokines in this system, both spontaneous (TNFα, IL-6), and induced (TNFα, IL-6 and IL-17). It should be noted that the degree of inhibitory effect caused by phytoextracts was not inferior, and, in relation to individual cytokines (TNFα and IL-17), was superior to Immunal, an Echinacea-derived preparation. We have revealed inhibitory effects of clover and chicory phytoextracts, as well as their combinations with MTX, on the production of proinflammatory cytokines (TNFα, IL-6, IL-17) by human peripheral blood mononuclear leukocytes. Potentiating action of phytoextracts manifested as enhanced inhibitory effect of cytostatic MTX on the production of IL-6 by lymphocytes and the appearance of an anti-inflammatory effect on TNFα and IL-17. The most pronounced immunoregulatory effect and potentiation of anti-inflammatory MTX action was obtained by the chicory phytoextract, with both extracts exceeding the effect of Immunal, a commercial comparison drug.

Protein phosphatase PPM1D (Protein phosphatase, Mg²⁺/Mn²⁺ dependent, 1D) is one of the key regulators of DNA damage-induced stress response, cell cycle and apoptosis. PPM1D overexpression is detected in a large number of both solid (lung cancer, breast cancer, etc.) and hematological (acute myeloid leukemia) malignancies, making PPM1D an important prognostic marker in oncology. Special attention should be paid to PPM1D overexpression in colorectal cancer (CRC), the third most common oncological disease since this index correlates with increased tumor size, metastasis, unfavorable survival prognosis, and the development of drug resistance. Drug resistance may be associated with direct dephosphorylation of p53 and other components of the ATM-p53 signaling pathway by PPM1D, also acting as a negative regulator of NF- κB. It is likely that PPM1D overexpression in CRC tumor cells may lead to a decreased synthesis of important proinflammatory cytokines and development of an immunosuppressive tumor microenvironment, which may significantly worsen the outcomes of therapy. At present, the role of PPM1D in regulating the inflammatory response in CRC remains insufficiently studied. The aim of this work was to compare the effect of chemical PPM1D inhibition using its selective inhibitor GSK2830371 and genetic knockout of PPM1D in the human CRC cell line HT-29 under conditions of the NF-κB signaling pathway induction with TNF treatment. In this study, we used the HT-29 cell line, as well as earlier obtained HT-29 cell line with PPM1D gene knockout, and HT-29 cell line with PPM1D overexpression. The cell lines were cultured under standard conditions. For experiments, TNF (20 ng/mL) and GSK2830371 (10 μM) were supplied. The cell lines were incubated with GSK2830371 for 24 hours, and with TNF for 12 hours. Cytokine production was evaluated using xMAP INTELLIFLEX multiplex technology, and gene expression was measured by real-time PCR. Results: The multiplex assay of cytokine secretion levels revealed that, neither incubation of cells with GSK2830371 nor PPM1D knockout led to changes in the cytokine profile without stimulation as compared to the intact cell line, and did not cause a significant increase in production of pro-inflammatory cytokines and growth factors after TNF stimulation of the NF-κB pathway. In the case of the NF-κB pathway stimulation with TNF and PPM1D inhibition, we did not detect any significant increase in production of proinflammatory cytokines and growth factors. When evaluating the HT-29 cell line with PPM1D overexpression using real-time PCR, a statistically significant increase in TNF, IL-8, and IL-1b expression was observed in response to TNF treatment compared to the wild-type line. This finding is inconsistent with data on the negative regulation of NF-κB pathway by PPM1D phosphatase. In general, it was shown that PPM1D gene knockout didn’t significantly affect the level of cytokines (IL-8, GM-CSF, etc.) controlled by NF-κB transcription factor in the case of TNF induction, as compared with effects of a selective inhibitor GSK2830371. Meanwhile, overexpression of PPM1D was associated with increased expression of proinflammotory cytokine genes, e.g., IL-8, TNF, IL-1b, upon induction of the NF-κB pathway by TNF.

Infectious diseases and immune disorders present a problem for mankind for centuries. To combat various diseases and infections, it is essential to gain understanding of how immune responses are triggered and modulated. In this regard, Toll-like receptors (TLRs) have become one of the main topics of biomedical research, since this family of proteins acts as one of the early determinants of immune response activation. Stress factors are among the most common causes of changes in the immune response which lead to rearranged response of blood leukocytes, altered hormonal levels and cytokine production. It has also been shown that TLR4 gene expression increases under stressful conditions. Endogenous damage-associated molecular factors (DAMPs, or alarmins) are known to be potential ligands of Toll-like receptors. One may assume that, TLR antagonists may be among the endogenous compounds whose concentration increases under unfavorable conditions, Their task is to prevent excessive expression of these receptors. The aim of the study was to determine how preventive administration of the endogenous antimicrobial peptide defensin RatNP-3 affects TLR3 and TLR4 gene expression in hypothalamus and spleen of rats after acute emotional and physical stress induced by forced swimming in cold water for two minutes. Three hours after the stress exposure to the rats, the spleen and hypothalamus were removed from the animals, RNA was isolated and a reverse transcription reaction was performed to obtain cDNA. Expression of TLR3 and TLR4 genes was assessed, with a reference to the housekeeping gene GAPDH (glyceraldehyde-3-phosphate dehydrogenase) expression, being determined by real-time PCR. Three hours after stress exposure, the expression of TLR3 and TLR4 genes was found to increase in hypothalamus and spleen. However, the pre-exposure intraperitoneal administration of defensin reduced the expression level of these genes only in splenocytes, but did not affect their expression in hypothalamus. These results indicate to the stress-induced systemic activation of Toll-like receptors in hypothalamic structures of the brain and spleen cells. Since the administration of endogenous defensins did not affect expression of TLR genes in hypothalamus, one may suggest that the regulatory action of neutrophilic defensins is not mediated via central regulatory mechanisms.

Arthrogenic muscle inhibition is a poorly studied phenomenon that occurs in 30 to 50% of all capsular-ligamentous injuries in the knee joint. The study of the dynamics of myokine levels in the blood after the injury with development of arthrogenic muscle inhibition is important for understanding the processes of restoration of the motor segment structures. Objective of our study was to analyze the changes in blood myokine contents in patients with arthrogenic muscle inhibition (AMI) caused by traumatic injury to the anterior cruciate ligament (ACL) of knee joint. Materials and methods: The study included 58 men involved in aerobic sports (athletics, swimming, basketball) with ACL injury. To identify the AMI phenomenon, wee performed electromyographic (EMG) study of the straight head of the quadriceps femoris muscle of the injured limb using a 4-channel EMG/EP system “Viking Quest” (Nicolet, USA). Myokine levels in venous blood were determined using ELISA test systems: IL-6 (Vector-Best, Novosibirsk); concentration of transforming growth factor β, decorin, myostatin (Cloud-Clone Corp. (China); VEGF (BioKhimMak CJSC). The control group consisted of 12 healthy men, average age 34.2±2.4 years. Statistical processing of the material was carried out with Statistica. vers.10.0 package (StatSoft Inc., USA). Results. In patients with ACL injury and AMT phenomenon, a significant decrease in blood concentrations of IL-6, transforming growth factor β and proteoglycan – decorin were found like as increased amounts of VEGF and MSTN, which, along with TGF-β, belong to the group of growth factors when compared with the appropriate indices in patients with ACL injury without AMT phenomenon. Discussion: A decrease in the level of IL-6, decorin and VEGF may be a consequence of forced hypokinesia in ACL injury, and the AMT formation may also result from increased myostatin blood levels, which is a negative regulator of myogenesis. Conclusion: The changed myokine concentrations in peripheral blood during traumatic damage to the capsular-ligamentous apparatus of the knee joint clearly suggest an involvement of muscle secretome into traumatic tissue damage and development of arthrogenic muscle inhibition phenomenon.

Despite the increased risk of bone fractures in patients with malignant neoplasms (MN), especially breast cancer (BC), bone health assessment and preventive treatment of osteoporosis (OP) still remain understudied. The aim of our work was to investigate the significance of systemic inflammatory markers in relation to severity of osteoporotic changes, and to evaluate their association with the estimated 10-year risk of low-energy fractures determined by FRAX in postmenopausal patients with breast cancer. Patients and methods: The study included 85 postmenopausal women with different malignancies, including 40 BC patients. All patients with BC underwent dual-energy X-ray absorptiometry, the 10-year probability of fracture was assessed by FRAX. IL-1β, IL-6, and TNFα were measured by quantitative enzyme-linked immunosorbent assay. The mean time since diagnosis of MN until referral for osteoporosis (OP) was 3 (2.0-4.0) years. In patients with MN, OP was diagnosed in 51.2% of cases, and osteopenia – in 37.2%. In the group of BC patients, osteopenia was documented in 16 patients, OP, in 19 cases. Adjuvant chemotherapy was performed in 42.5% of cases among breast cancer patients, and adjuvant hormonal therapy was performed in 87.5% of cases (different postmenopausal hormone therapies were used). When comparing the cytokine levels in BC subgroups with presence (47.5%) or absence of OP, we have found that IL-1β was higher in patients with OP as compared to both normal persons and osteopenic patients (p = 0.027 and p = 0.029, respectively); IL-6 was higher only in patients with OP compared to normal subjects (p = 0.011); TNFα in OP and osteopenia exceeded those values in OP-free cases (p = 0.001 and p = 0.039, respectively). TNFα levels correlated with the risk score for large osteoporotic fractures (FRAX:MOF) (r_S = 0.33, p = 0.036) and IL-6 (r_S = 0.55). A higher 10-year risk of vertebral fractures (p = 0.003) was observed in the group of BC patients with ‘high’ (> median) TNFα levels. In summary, proinflammatory cytokines seem to be involved in bone resorption processes. Postmenopausal BC patients have an increased estimated 10-year risk of low-energy spine fractures associated with high TNFα levels.

The incidence of malignant blood diseases has been steadily increasing over past decades. Unlike many other types of malignant neoplasms, blood cancers often occur at a young age, being also the main cause of death among all hematopoietic disorders in pediatric patients. Mutation events in hematopoietic stem cells are the cause of blood cancers which subsequently lead to increasimg number of tumor clones and displacement of healthy cells in the niches they occupy thus leading to a number of changes in blood and bone marrow, including irreversible ones. The aim of this study was to assess the subpopulation composition of pluripotent hematopoietic stem cells in patients with blood cancers and healthy donors. The study included patients with blood cancers (n = 13), including acute lymphoblastic leukemia (ALL; n = 3), acute myeloid leukemia (AML; n = 3), and multiple myeloma (MM; n = 7), as well as healthy donors (n = 4). The phenotypic composition of hematopoietic CD34⁺CD38^- pluripotent cells was assessed by flow cytometry using the following monoclonal antibodies: CD34 APC (BioLegend, USA), CD38 PE-Cy7 (ElabScience, China), CD45RA PerCP (ElabScience, China), CD90 APC-Cy7 (Cloud-Clone Corp., USA), Lin^- (cocktail CD3/14/16/19/20/56) FITC (BioLegend, USA). The following populations were assessed: hematopoietic stem cells (Lin^-CD34⁺CD38^-CD45RA^-CD90⁺) and pluripotent progenitors (Lin^-CD34⁺CD38^-CD45RA^-CD90^-). In patients with hemoblastoses, the relative number of cells with Lin^-CD34⁺CD38^-CD45RA^-CD90⁺ phenotype proved to be increased, thus corresponding to hematopoietic stem cells, but not pluripotent progenitor cells. At the same time, the number of pluripotent progenitor cells tended to decrease in acute myeloid leukemia. We have observed some changes in the subpopulation composition of pluripotent hematopoietic stem cells in patients with blood cancers, when compared with healthy donors.

Microglial cells play a leading role in development of neuroinflammation. Activation of microglia leads to the formation of reactive phenotypes that can both contribute to the development of neuroinflammation and ensure its relief. Microglia activation is accompanied by metabolic reprogramming or changes in the metabolic pathways activity and the content of specific metabolites supporting a particular phenotype. An opportunity of phenotype switching due to metabolomic reprogramming may have real therapeutic potential. However, currently there are limited data on changes in composition of metabolites and activity of metabolic pathways in microglial cells under the influence of neuroinflammatory factors. In this regard, the purpose of this work was to conduct a non-targeted metabolomic study to assess changes of metabolites profiles in microglial cell line SIM-A9 exposed to hypoxia, as well as during TLR4 activation. Metabolite profiling of cell extracts exposed to hypoxia or lipopolysaccharide was performed using high-performance liquid chromatography and high-resolution mass spectrometry, followed by bioinformatics analysis of the data. The performed studies have shown that hypoxia, as well as TLR4 stimulation, lead to noticeable changes in the metabolism of microglial cells. At the same time, the nature of these changes depends on the type of stress exposure and its duration. Changed activity of glutathione and arginine metabolic pathways may serve as a marker of the polarization of microglial cells after hypoxic exposure. The activation of TLR4 by lipopolysaccharide leads to modulation of pathways associated with energy metabolism, as well as changes in the metabolic pathways of aromatic amino acids. One may suggest that the analytic approach used in this work will allow us to further investigate the dynamics of metabolic changes under the influence of proinflammatory factors of various origin and to gain detailed data on their role in metabolic reprogramming of microglial cells at various stages of neuroinflammation.

Recent studies have shown that healthy adults have circulating double-positive (DP) T cells at small concentrations. These T cells develop from CD4⁺ and CD8⁺T cell populations and co-express CD4 and CD8 on their surface. According to the expression of CD4 and CD8 markers, the DP T cells can be divided into two subpopulations: CD4^brightCD8^dim and CD4^dimCD8^bright. The phenotypic and functional features of these subpopulations are currently not fully understood. The aim of the study was to identify the phenotypic characteristics of CD4^brightCD8^dim and CD4^dimCD8^brightT cells in peripheral blood from healthy adults depending on the expression of maturation antigens. The cell phenotyping was performed by flow cytometry using antibodies against the following human surface antigens: CD57 (FITC-conjugated), CD62L (ECD-conjugated), CD28 (PerCP/Cy5.5-conjugated), CD27 (Pe/Cy7-conjugated), CD4 (APC-conjugated), CD8 (APC-AF700-conjugated), CD3 (APC-AF750-conjugated), CD45RA (Pacific Blue-conjugated), and CD45 (Krome Orange-conjugated). The differences between the groups were estimated using Mann–Whitney U test. Results were presented as median and interquartile range – Me (Q_0.25-Q_0.75). A total pool of DP T cells was detected, constituting 0.73% (0.42-1.61) of the total CD3⁺T cell population, at a total concentration of 11 cells/μL (6-20). The percentage of CD4^brightCD8^dim and CD4^dimCD8^brightT cells was within 0.25% (0.18-0.44), and 0.29% (0.20-0.98) at concentrations of 4 cells/1μL (2-7) and 5 cells/1μL (2-12), respectively. Effector memory cells (CD45RA^-CD62L^-) and effector memory cells re-expressing CD45RA (CD45RA⁺CD62L^-) were predominant in CD4^brightCD8^dim T cells, whereas central memory phenotype (CD45RA⁺CD62L⁺) prevailed among CD4^dimCD8^brightT cells. Moreover, a reduced level of the “naïve” phenotype (CD45RA⁺CD62L⁺) was noted in CD4^brightCD8^dim and CD4^dimCD8^brightT cell populations. An increase in CD57 expression on the surface of CD4^brightCD8^dimT cells with a simultaneous decrease in CD27 and CD28 was also detected as compared to CD4⁺T cells. In turn, CD4^dimCD8^brightT cells increase the expression of CD28 and decrease the expression of CD57 on their surface if compared to CD8⁺T cells. DP T cells have a more mature phenotype being often represented by memory cells.

Efficiency of the IVF procedure is assessed not only by the indexes of clinical pregnancy onset but also by the proportion of live births, since about a third of pregnancies end in termination, which certainly depends on many factors. Colony-stimulating factors may be considered potential predictive markers of the induced pregnancy development and resulting into live birth. To evaluate the predictive value of the CSF-1 system (serum CSF-1 concentration and carriage of CSF1R gene polymorphisms) in the setting of live birth after IVF-induced pregnancy in women with tubo-peritoneal infertility. 88 patients undergoing IVF aged between 25 and 40 years were assigned to the following groups: Group I (n = 32): patients whose post-IVF pregnancies resulted in live births at Week 24 or later; and Group II (n = 52) which included patients whose pregnancies did not occur or resulted in spontaneous miscarriages. ELISA testing determined the CSF-1 levels twice: on pre-IVF menstrual cycle (Days 3-4), and on post-embryo-transfer (Day 15). Genotyping of the CSF1R gene rs3216780 and rs38669350 polymorphic markers was performed by PCR with subsequent Sanger sequencing. CSF-1 levels rised to post-embryo-transfer Day 15 (3.9-fold in Group I and 1.8-fold in Group II); the appropriate values in pregnant women of Group II were reliably higher than in comparison group (p = 0.0017). Most women whose pregnancy resulted in live births carried the del/G rs3216780 and TG/CA rs386693509 genotypes of CSF1R gene. Univariate analysis identified the following predictors for completion of induced pregnancy by delivery: (1) CSF-1 levels in peripheral blood from 121.3 to 314.8 pg/mL at the preconceptional stage, and 963.3 to 1682.8 pg/mL on Day 15 after embryo transfer; (2) harboring the del/G rs3216780 genotypes and TG/CA rs386693509 gene CSF1R. In combination. These predictors were observed in 66.7% of women from group I and in 7.7% from group II. The CSF-1 system plays an important role in performance of female reproductive function and the revealed prognostic indicators, i.e., pre-conception and post-ET Day 15 serum CSF-1 concentrations, and carriage of the following CSF1R gene variants: del/G rs3216780 and TG/CA rs386693509 genotypes which can be used as predictors of the completion of induced pregnancy by childbirth.

Holothurians (sea cucumbers) are known for their high regenerative ability. Extract from Far-Eastern holothurian tissues (EH) is able to accelerate wound healing. In vertebrates, two types of macrophages display different roles in regulation of healing at its different stages. In holothurians, two enriched fractions of phagocytes (P1 and P2) are also identified being the analogues to macrophages. The mechanisms of EH influence on separate types of phagocytes in the wound healing remains unexplored. It was of interest to study the effect of EH in model experiments, in comparison with substances known as inducers of macrophage polarization The aim of this work was to study the effect of EH on the number and phenotype of phagocytes P1 and P2 in the wounded holothurian Eupentacta fraudatrix in comparison with efficiency of granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor α (TNFα). The experimental animals (n = 4 to 6) received a superficial wound with a lancet. Some animals were additionally injected with GM-CSF, TNFα or EH. After 0 min and 1 day phagocytes P1 and P2 were isolated by centrifugation of coelomic fluid in a density gradient of Ficoll-Verographin. The concentration of coelomocytes and content of phagocytes P1 and P2 were determined by light microscopy. The binding of cells to FITC-labeled lectins from Dolichos biflorus (DBA), Canavalia ensiformis (conA) and Glycine max (SBA) was assessed using a fluorescence microscope. The wound length was measured at initial time point (0 min.) and 72 h. Surface damage of the holothurian body caused an increase in concentration of coelomocytes and contents of P1 phagocytes, but decreased the number of P2 phagocytes. Changed cell numbers in coelomic fluid of wounded animals and decrease in their differentiation, assessed by DBA lectin binding upon exposure to the test substances indicate that the cytokines apparently caused a shift in the ratio of tissue phagocytes in favor of P1 phagocytes, while EH promoted P2 phagocytic population. Evaluation of ConA cell binding revealed that cytokines suppressed the functional activity of P1 phagocytes upon wound injury. EH did not only suppress the functional activity of P1 phagocytes, but also stimulated the activity of P2 phagocytes, and promoted wound healing, as compared to cytokines. Acceleration of wound healing under the influence of EH is associated with preferential activation of P2 phagocytes and their recruitment into tissues. This finding suggests an important role of P2 phagocytes in tissue repair.

Polyhydroxylated fullerenes, commonly referred to as fullerenols, are among the most promising carbon allotropes due to their hydrophilic nature, stability, and low toxicity. Natural Killer (NK) cells are key players of the antiviral and antitumor immune response. However, they have been largely understudied as targets for fullerenol nanoparticles. The aim of this work was to assess the immunocompatibility of hydroxylated fullerenol C₆₀(OH)_22-24 with СD3^-CD56⁺NK cells from human peripheral blood, as well as to study internalization of these nanoparticles into the cells. The studies were conducted with mononuclear cells from peripheral blood of healthy donors (n = 4). Fullerenol (MST-WS60-Bio, fullerenol C₆₀(OH)₂₄ 99.99%, MST-Nano, Russia; cluster size approximately 130 nm) was used at concentrations of 200, 100, 50, 25, 12.5, 5, 2.5, 0.5, and 0.25 μg/mL. Wells without added nanoparticles served as controls. Cells were incubated in the presence of fullerenol for 24, 48, and 72 hours under conditions of 5% CO₂ and 37 °C. The viability of NK cells (CD3^-CD56⁺) and the adhesion/internalization of fullerenol into the cells were assessed using flow cytometry. We have found that fullerenol nanoparticles at concentrations ranging from 0.25 to 200 μg/mL did not exhibit cytotoxicity towards NK cells during the observation periods of 24, 48, and 72 hours. Thus, no statistically significant decrease in the percentage and absolute number of live NK cells was detected in cultures with fullerenol over these time period. The study also showed that NK cells did not demonstrate adhesion/internalization of fullerenol nanoparticles at low concentrations (0.25-50 μg/mL) during all observation periods. However, high concentrations of fullerenol were detected inside NK cells at 48 and 72 hours of observation. After 72 hours, approximately 10% of NK cells did adhere/internalize fullerenol particles at a concentration of 100 μg/mL, with about 50% of cells consumed the particles at 200 μg/mL. Thus, for the first time, it was demonstrated that NK cells adhere/internalize fullerenol at high concentrations (100 and 200 μg/mL), and the percentage of fullerenol-positive cells increases at both longer cultivation period and higher nanoparticle concentration. Fullerenol didn’t exhibit cytotoxic effects on the studied cell population.

Active and passive tobacco smoking is one of the widespread low-toxicity factors affecting animals and humans. In previous studies, the authors investigated morphological and immunological parameters in passively smoke-exposed rats. The aim of our study was to continue research in this direction focusing on the effects of a synthetic KK1 peptide, a structural analogue of the ACTH primary sequence (15-18) (Acetyl-(D-Lys)-Lys-Arg-Arg-amide) with antioxidant and stress-protective properties, on the phagocytic activity of peritoneal macrophages and intensity of free-radical oxidation in the liver and blood serum. Immunological and biochemical parameters were assessed in 60 pups from tobacco smoke-exposed and non-exposed Wistar rats. The pregnant rats were subjected to tobacco smoke (8 hours a day, from 1^st to 20^th day of gestation). Control groups received saline, while experimental groups were administered KK1 (intranasally, at a dose of 40 μg/kg, five times during the 10-day period). 21 days postpartum, the little rats were evaluated for phagocytic indices, circulating immune complex levels (CIC), hepatic enzyme activity (alanine aminotransferase (ALT), aspartate aminotransferase (AST)), oxidative stress markers (malondialdehyde (MDA), diene conjugates (DC), and antioxidant enzymes (superoxide dismutase (SOD), catalase). The study has shown that prenatal tobacco smoke exposure in rat offspring was associated with reduced phagocytic activity, but elevated neutrophil metabolic activity, increased serum AST activity, activated free radical oxidation (elevated MDA, DC), along with suppression of endogenous antioxidant defense mechanisms (decreased SOD and catalase). Administration of the KK1 compound was associated with normalized phagocytic indices, reduced AST activity and restored antioxidant defenses. These findings support the opinion on antioxidant properties of KK1 under passive smoking conditions, highlighting its immunoprotective effects. The effects of KK1 compound may be associated with modulation of synaptic membrane fluidity, regulation of receptor functions, protein phosphorylation processes, and suppression of excessive cytokine synthesis. The observed reduction in free-radical oxidation products and enhancement of catalase activity align with existing evidence of KK1’s antioxidant and stress-protective efficacy. The KK1 compound has demonstrated antioxidant and immunoprotective effects by mitigating the adverse consequences of prenatal tobacco smoke exposure in rat offspring. These findings support its potential application in studies investigating the impact of low-toxicity environmental factors in experimental animal models.

Preterm birth is one of the most urgent problems in neonatology. Every year, about 10% of all children are born before their due date. Successful or failed care over the neonatal period in this category are the main factors of neonatal and infant mortality and disability. High-tech and expensive medical services are required to care for premature infants. Despite technological advances, the increasing amount of scientific knowledge, changing therapeutic approaches, growing skills of clinicians do not provide the desired efficiency, and the results of medical care still are far from success for the extra-premature children. The key issue in transition from intrauterine to extra-uterine life is the time point of external respiration. The main efforts for sustaining the preterm child are aimed at its respiratory protection, since breathing is one of the main vital functions. Therefore, respiratory disorders occupy a special place among the pathologies in premature infants. They include a number of diseases that impair normal course of neonatal period, being characterized by negative consequences, determining the quality of life in premature children as well as their families. In the premature birth of a child, various prenatal factors affect the body, contributing to the morphofunctional immaturity and altered adaptation mechanisms. As a result, such newborns need much more high-tech medical care to successfully adapt to life outside the womb. Despite all the advances in protection of respiratory function in the newborn, the implementation of respiratory support can trigger pathological cascades, which result in a «pathological circle» leading to chronic disease. The main mechanisms of damage are realized through immune-mediated and inflammatory reactions. The underlying pathological events are triggered during the intrauterine period, due to imbalance between pro-and anti-inflammatory mechanisms, thus causing impairment of lung maturation. After birth, the immune system of a premature baby has its own features that are formed ante partum. This condition, arbitrarily referred to as «immaturity immunodeficiency», requires further study for deeper understanding of its mechanisms.

Over last decades, growing incidence of obesity is registered among children and adolescents, which is the main risk factor for chronic diseases, including cardiovascular disorders, diabetes mellitus, and endocrinopathies which lead to menstrual irregularities and infertility in reproductive period. Under conditions of overnutrition, adipose tissue macrophages are polarized into the M1 phenotype and secrete a number of proinflammatory cytokines and chemokines that promote inflammatory response due to chemotaxis of immunocompetent cells that affect metabolism, thus leading to decreased production of anti-inflammatory cytokines, and causing impaired adipogenesis. A close relationship has been observed between obesity and activation of immune system factors, being a sufficient factor of energy imbalance. However, their role in the genesis of oligomenorrhea has not been studied so far. The purpose of our work was аnalysis of cytokine status in adolescent girls with obesity and oligomenorrhea. The study involved 30 adolescent girls with obesity and oligomenorrhea (Group I). A comparison group included 23 patients with oligomenorrhea without signs of metabolic syndrome (Group II). The control group included 20 practically healthy patients. The level of omentin in blood serum was determined by ELISA using diagnostic kits BioVendor (Czech Republic); the level of IL-6, MCP-1, IFNγ was measured with diagnostic kits from BenderMedSystems (Austria). Mathematical evaluation of results was carried out using the Statistica 10.0 program. The Mann–Whitney criterion was used to determine the differences between the groups. Statistically significant values were taken as p < 0.05. Obesity is associated with increased expression of proinflammatory cytokines and chemokines, which may stimulate signaling cascades that impair metabolic processes in adipose tissue. IL-6, MCP-1, IFNγ act as modulators that promote inflammation, which is crucial for the development of insulin resistance conditions. Discoordination of immunoregulatory processes. contribute to progression of the inflammatory events and confirm the role of immune factors in the genesis of ovarian dysfunction in adolescent girls. Improved understanding of underlying immunopathological processes accompanying obesity in adolescent girls may be useful for predicting oligomenorrhea and developing potential treatment approaches.

Patients with hyper-IgE syndrome are characterized by eosinophilia, low levels of inflammatory markers, severe destructive pneumonia, chronic mucosal candidiasis, severe atopic dermatitis, skeletal lesions: osteopenia and pathological fractures, scoliosis, delayed change of primary teeth. The pathogenesis of this syndrome is based on defects in signal transduction from cytokine receptors, caused by mutations in the STAT3 gene (autosomal dominant form), ZNF341, DOCK8, PGM3 and CARD11 (autosomal recessive form) and in genes encoding cytokine receptor subunits (IL6ST, etc.). The aim of our study was to analyze lymphocyte subpopulations in patients with different forms of hyper-IgE syndrome. The study included 9 patients with hyper-IgE syndrome. Lymphocyte subpopulations were assessed by flow cytometry; total IgE, by immunoturbidimetry; DNA sequencing, by means of NGS methodology. Mutations in different exons of the STAT3 gene and in the IL6ST gene were detected in patients. No statistically significant differences were found between patients and control group of CD3 T cell subpopulations, i.e., CD4 T helpers (naive and memory cells), CD8 T cytotoxic (naive and memory cells), early thymic emigrants, Treg cells, T helpers (type 1 and 2) (p > 0.05). However, the subpopulation of T helpers 17 was significantly reduced, both in relative (p < 0.001) and absolute numbers (p = 0.003) only in patients with mutations in the STAT3 gene. In patients with hyper-IgE syndrome, we have found a reduction of both relative (p < 0.001) and absolute numbers of unswitched (p = 0.001) and switched memory B cells (p = 0.007). A decreased relative number of plasmablasts (p = 0.022) and activated B lymphocytes (p = 0.001) was also observed. The number of T helpers 17 depended on the type of hyper-IgE syndrome. Memory B cells were reduced in all mutation types. The method of assessing T helper 17 demonstrated its diagnostic efficiency. The differences were observed in clinical pattern and severity of the disease depending on the STAT3 protein domain mutation. However, further studies with a larger number of patients are required.

Interleukins play a key role in development of bronchial asthma endotypes, thus determining individual clinical course of the disease and the efficiency of therapy. Exhaled breath condensate (EBC) represents a promising non-invasive biomaterial for assessing local airway inflammation in asthma. Only limited data exist on the opportunity of cytokines detection in EBC of pediatric patients. The aim of our study was to assess the opportunity of detection and diagnostic significance of IL-4, IL-5, IL-13, and IL-17A in EBC of children with asthma using high-sensitivity multiplex analysis. The study included 169 children aged 6-17 years (104 with asthma and 65 healthy controls). EBC was collected using RTube (Respiratory Research, USA), samples were concentrated, and interleukin levels were determined by multiplex analysis on the MAGPIX (Luminex, USA) platform. Analysis of interleukins in exhaled air condensate showed that children with bronchial asthma exhibit statistically significant changes compared to the control group. Children with asthma showed significantly increased detection rates of IL-13 (53.9% vs 30.8%, p = 0.003) and IL-17A (57.7% vs 27.7%, p = 0.001) compared to controls. The detection frequency of these cytokines progressively increased with disease severity, reaching 72.7% for IL-13 and 63.6% for IL-17A in severe asthma. Our results demonstrate the possibility of detecting key cytokines in exhaled air condensate in children with bronchial asthma using highly sensitive multiplex analysis after prior concentration of samples. Detection of IL-13 and IL-17A in EBC can be considered a potential non-invasive biomarker of asthma severity in children. However, further studies with larger patient populations and standard sample concentration technique are required for clinical implementation of the method. These data demonstrate a promise for usage of EBC for non-invasive assessment of local airway inflammation in children with bronchial asthma.

The search for biomarkers of severe community-acquired pneumonia in children is an urgent clinical task. Cytokines, in particular IL-6 and IL-8, may be considered indices of lung tissue inflammation, being regulators of the immune response. The aim of the study was to evaluate serum levels of IL-6 and IL-8 in children with pneumonia of different severity, and to analyze the relationship of these parameters with origin of the pathology and biomarkers of systemic inflammation. The enzyme immunoassay method was used to determine the concentrations of IL-6, IL-8, and procalcitonin in blood serum samples of 37 children with community-acquired pneumonia of varying severity upon their admission to the hospital. The examined children were divided in 2 groups: (1) patients with severe pneumonia (n = 13); (2), patients with mild pneumonia (n = 24). It was found that the serum levels of both interleukins were higher in children with severe community-acquired pneumonia. Thus, in children with severe disease, the level of IL-6 is 2.2 times, and the level of IL-8 is 3.6 times higher than in patients with mild pneumonia. Positive correlations of moderate strength have been revealed between the severity of the disease and serum levels of IL-6 (r = 0.68, p < 0.0001) and IL-8 (r = 0.57, p < 0.0001). Significant correlations of the studied interleukins were found among the cytokine contents (r = 0.49, p = 0.002), and with other indices of systemic inflammation. IL-6 levels correlated with leukocytosis (r = 0.42, p = 0.009), absolute neutrophil counts (r = 49, p = 0.002), serum procalcitonin (PCT) concentration (r = 0.53, p < 0.001). IL-8 levels correlated with PCT concentrations (r = 0.49, p = 0.002) and CRP (r = 0.35, p < 0.05). Conclusions. The results obtained suggest that the development of severe community-acquired pneumonia in children is associated with increased serum levels of IL-6 and IL-8, as well as laboratory parameters of systemic inflammatory response such as leukocytosis, concentrations of PCT and CRP. The revealed correlations indicate the involvement of IL-6 and IL-8 in development of a systemic inflammatory response associated with this disorder. The data obtained suggest an opportumity of using serum IL-6 and IL-8 levels in children with community-acquired pneumonia as promising biomarkers for assessing the disease severity.

SARS-CoV-2 seroprevalence is an important index of coronavirus infection incidence, especially among populations with different mobility levels. International travel may facilitate transmission of the virus and affect the level of herd immunity, but the extent of this influence remains poorly understood. The present study was conducted in Chelyabinsk from 27.10.2020 to 30.01.2023. 660 blood samples were analyzed for IgM antibodies, and 843 samples for IgG antibodies to SARS-CoV-2 antigen in order to assess seropositivity rates of city residents depending on their recent international travel experience. Antibodies to coronavirus infection were determined by enzyme-linked immunosorbent assay (ELISA) using Multiskan FC equipment and Vector-Best reagents. A questionnaire filled by the participants helped to establish the fact of travel and the countries visited. The results of this study showed a trend towards higher IgG seropositivity among individuals who had traveled internationally (p = 0.07), although statistical significance was not reached. The overall seroprevalence rate was higher for IgG (67.38%) compared to IgM (32.73%), thus, probably, suggesting a history of infection or vaccination in the cohort. The highest IgG seroprevalence was observed among persons who returned from Turkey, Kazakhstan, and Egypt. No statistically significant differences in seroprevalence were found between men and women. The results suggest a trend towards higher seroprevalence among the international travelers, thus being indicative for increased risk of infection during the trips. However, a lack of statistical significance requires further surveys in larger groups, as well as considering their vaccination status, seroconversion dynamics, disease time profile, and repeated testing. Despite these limitations, these results can be used to improve epidemiological surveillance measures and planning epidemiological measures in order to prevent COVID-19 and other respiratory infections, including the factor of international travelling.

Since the end of 2019, people have been faced with infection, caused by a new strain of coronavirus – SARS-CoV-2. This disease has led to a pandemic, one of the global problems of mankind. Despite clinical manifestations of COVID-19 became milder with time, resembling features of seasonal viral infections, the persistent disturbances in various organs and systems were identified in former patients. It was found that, after suffering from COVID-19, a significant number of patients experience numerous disorders in both general health and complications of existing chronic diseases, including herpesvirus reactivation nd papillomavirus infection. In this regard, the scientific community has an additional task, a comprehensive and in-depth study of post-COVID syndrome to identify ways to improve the condition of patients. Currently, it has been revealed that about 90% of the world’s population is infected with herpesviruses. In some cases, one person may be found to have co-infection with different herpesviruses. Herpesvirus infections may be associated with a lot of conditions, from local labial herpes to generalized forms, malignant neoplasms and congenital malformations. It can occur both in acute and latent forms. The study of herpesvirus infection in the context of post-covid syndrome is one of the most pressing problems of modern medicine. The purpose of this study was to evaluate the changes in immune indexes in patients with post-COVID syndrome and with laboratory and clinically confirmed herpes virus type 6. To this purpose, changes in innate immune response indicators such as the complement system, phagocytic activity of neutrophils were assessed. Clinical data, immunological tests (enzyme-linked immunosorbent assay and NBT test with nitroblue tetrazolium), and statistical analysis methods (Mann–Whitney criterion) were used for the study. The results have shown that that adverse reactions caused by the previous coronavirus infection are characterized by new aspects of disorders in adaptive and innate immune systems, thus leading to more serious consequences for immune system and the entire body, having been carefully studied and analyzed. The revealed changes indicate that the more pronounced disorders are observed in patients with post-COVID syndrome and a history of herpes virus type 6. This finding highlights the need for a more detailed study of their immune status, in order to develop individualized approaches to immunocorrection of immune system disorders in this group of patients, taking into account their herpesvirus history.

The COVID-19 pandemic caused by the SARS-CoV-2 virus has led to far-reaching consequences. The changes caused in COVID-19 patients may persist for more than 6-12 months after acute phase of the disease promoting post-COVID disorders of immune system. Patients who have had acute COVID-19 in both mild and severe forms suffer from various manifestations of post-COVID syndrome. However, the severity of these manifestations is quite variable. The aim of the study was to assess the effect of lung damage extent in acute period of COVID-19 on the severity of clinical manifestations in post-COVID syndrome as exemplified by immune-mediated syndromes, i.e., autoimmune disorders, proliferative conditions, and allergopathology. 131 patients who had who had a history of SARS-CoV-2 infection were examined. Anamnestic data from outpatient cards of patients were used for the study. Using the ELISA diagnostics method, IgA, IgM, IgG specific to SARS-CoV-2, complement components C1q, C3a, C5a were determined. The studies revealed a connection between the severity of post-COVID syndrome and the severity of the acute COVID-19 course. The SARS-CoV-2 virus is able of activating complement, and this activation persists for a long time (more than six months). This finding explains presence of clinical manifestations of post-COVID syndrome in individuals who have had a mild acute form of COVID-19 without CT-detected lung damage without phenotypes of immune system damage that we have previously identified (congenital – decreased expression of CD46 on T lymphocytes and decreased expression of CD46 on NK cells, and acquired – decreased level of T-cytotoxic lymphocytes and impaired level of B-cells CD45⁺CD3^-CD19⁺CD5⁺CD27⁺). The data obtained indicate that the examination of post-COVID patients should be carried out not only by their clinical characteristics, but also by assessing markers of their immune system in order to make a correct diagnosis and prescribe etiological and pathogenetic therapy, including immune therapy. Conclusions: 1. Autoimmune, proliferative and allergic diseases are directly related to disorders of the immune system. The severity of autoimmune disorders in the post-COVID period is more associated with basic corticosteroid therapy (GCS) both for the treatment of autoimmune processes and for the treatment of COVID-19 (except of treating autoimmune thyroiditis). GCS treatment used in acute period of infection reduced the number of recurrenct disorders. The situation is the opposite in rheumatoid arthritis: the use of GCS in the acute period of infection in patients already on basic corticosteroid therapy subsequently leads to an increase in the number of relapses in post-COVID patients. 2. In post-COVID patients, we revealed a trend towards an increase in the most clinically severe allergopathology: firstly, in all groups (52%) in the post-COVID period, exacerbations of such pathologies as Quincke’s edema, urticaria, anaphylaxis, vasculitis, alveolitis, and bronchiolitis became more frequent. These findings suggest that the worse condition of these patients in the post-COVID period was influenced by the past SARS-CoV-2 infection Allergic skin lesions were in second place in terms of the frequency of exacerbations (about 28%). 3. There is a tendency towards an increased frequency of proliferative diseases exacerbations in patients with more severe forms of acute COVID-19 infection. It should also be noted that the percentage of such patients is quite high, from 31.6% to 48%. 4. The SARS-CoV-2 virus may affect the complement activation system, thus explaining clinical manifestations of post-COVID syndrome in the persons who had a mild form of COVID-19 without evidence of lung damage immune system affection. Our data indicate that the examination of post-COVID patients should be carried out not only by assessing their clinical characteristics, but also by examining the state of the immune system in such patients in order to make a correct diagnosis and administer etiological and pathogenetic therapy, including immune therapy.

Vaccine prevention of disorders caused by the Varicella Zoster virus (VZV) is a priority of the World Health Organization’s program for eradication of socially significant and demographically important infections, being integrated into the Russian Federal healthcare program, by including VZV vaccination in the National schedule of vaccine prophylaxis. A mathematical model based on epidemiological data predicts that the vaccination coverage should be at least 60%, in order to ensure a significantly reduced incidence of chickenpox. The incidence of Herpes Zoster is also likely to decrease at later terms, while maintaining an adequate coverage level. Successful implementation of live vaccines to prevent the VZV-associated high-risk disorders is proceeds with expanding number of vaccines registered in the countries that have included vaccination in their National immunization programs. Development of a domestic vaccine is a pre-requisite for the import-replacing programs. The Mechnikov Research Institute of Vaccines and Sera has isolated and characterized wild strains of VZV that may be used to develop vaccines. Standard methods for studying the effectiveness of live VZV vaccines include assessment of adaptive immunity parameterd based on such indices as total level of antibodies to varicella zoster (GMI), geometric mean antibody titers (GMT) at certain time intervals, geometric mean multiple increase (GMFI) of antibodies to VZV over the same time period, and the level of seropositivity (defined as the percentage of subjects with an antibody titer > 1:8). However, the assessment of VZV effects on innate immunity is not studied routinely, being applied only for research purposes. To evaluate the innate immune response as an index of vaccination efficiency, one may use expression of Toll-like receptor (TLR) genes in response to vaccine administration. TLR genes encode immune receptors that recognize the structural components of RNA and DNA-containing viruses, including VZV. In turn, the TLR2, TLR4, and TLR9 expression levels are the markers of innate immunity activation, which is highly important when assessing post-vaccinal immune response. In the course of this study, the VZV strains obtained at the I.I. Mechnikov Research Institute of Vaccines and Sera were evaluated for their ability to induce innate immune response tested by the TLR2, TLR4 and ^TLR9 markers. The results obtained have enabled us to specify an optimal experimental sample for further studies aimed at obtaining an effective vaccine against VZV-associated infectious conditions.

Vaccination against mumps virus has sufficiently reduced, but not eliminated, the incidence of this infection. Incidence of this infection shows periodical increases, even among populations with high vaccination coverage. Immunity to the mumps virus is most often assessed by the serum level of specific antibodies, but T cell immunity is known is known to be more important for antiviral protection. The aim of the study was to compare two methods for assessing cellular immunity to mumps virus antigens in intact adults and those who had this infection. The study included 20 adults who had a story of mumps (Group 1) and 17 people who had not or were vaccinated against this infection (Group 2). Antibodies to the mumps virus were determined by ELISA technique. Cellular immunity was assessed by ELISpot test and by the percentage of CD8^hiCD107a⁺ lymphocytes upon recognizing the mumps virus antigens. None of the subjects in group 2 were found to have IgG antibodies, or cellular immunity using the ELISpot method or the percentage of CD8^hiCD107a⁺. In group 1, 2 of 20 subjects did not have IgG antibodies to the mumps virus, and 18 subjects had such antibodies at different levels. High level of cellular immunity to mumps virus in 10 subjects (9.44±1.27) was detected by ELISpot, with low levels detected in other 10 subjects (3.44±0.54). Cellular immune response to mumps virus based on CD107a expression on CD8^hi lymphocytes was not detected in 4 out of 20 individuals, but antibodies to this virus were found; other 4 persons had a low level (2.35 (1.9-2.86) %), and 12 subjects had a high level of cellular immunity to mumps virus (7.72-14.24) %). The cut-off level of 3.76% was defined thus discerning high and low levels of cellular immunity to mumps virus antigens with 100% sensitivity and specificity. Comparison of ELISpot method and determination of CD107a expression on CD8^hi showed a negative correlation r = -0.81, being mainly associated with different populations participating in cellular immune response detected by these two methods. Moreover, ELISpot evaluates IFNγ producers, and CD107a expression detects cells that respond with a cytotoxic attack to antigen recognition. Both methods are suitable for studying cellular immunity to mumps viral antigens.

Multiple sclerosis (MS) is a chronic progressive neurodegenerative autoimmune disease characterized by disseminated demyelination patches in brain and spinal cord, containing different subsets of immune cells, including CD8⁺T cells. Currently, CD8⁺T cells may be subdivided into three main subsets, including Tc1, Tc2 and Tc17, according to their cytokine production profile and phenotype. A balance between the cytolytic Tc1 and cytokine-producing Tc2 and Tc17 cell subsets seems to play crucial role in emergence of diverse pathological conditions including autoimmunity. Thus, we have examined the frequency of Tc cell subsets in peripheral blood of patients with relapsing-remitting MS (MS, n = 25), and healthy individuals (HC, n = 24) matched for sex and age. To analyze the frequency of CD8⁺T cell subsets, we used multicolor flow cytometry. We evaluated the relative and absolute frequencies of Tc1 (CCR6^-CXCR3⁺), Tc2 (CCR6^-CXCR3^-), Tc17 (CCR6⁺CXCR3^-) and Tc17.1 (CCR6⁺CXCR3⁺) cells, like as their relative distribution along the main maturation stages of CD8⁺T cells, including ‘‘naïve’’ (CD45RA⁺CD62L⁺), central (СМ) and effector (ЕМ) memory, as well as TEMRA (CD45RA⁺CD62L^-) cells. First, we have found that the relative frequency of Tc1 was decreased in MS group versus HC, whereas the relative and absolute frequencies of Тс17 of Тс17.1 were significantly elevated in MS patients. Next, our data revealed a significantly increased frequency of Тс17 cells at all analyzed stages of CD8⁺T cell maturation in peripheral blood samples from MS patients. Moreover, the differences against control group were more pronounced in the ЕМ and TEMRA CD8⁺T cell subsets which are able to migrate to inflammation sites (11.66% (4.75-14.69) versus 2.45% (1.48-3.89) and 4.91% (3.68-8.63) versus 0.41% (0.11-1.30), respectively, р < 0.001 in both cases). Hence, we provide some new insights in the frequency of ‘‘polarized’’ CD8⁺T cell subsets in patients with MS. The obtained data suggest Tc17 cells to be an important part in MS pathogenesis which may be used for development of new diagnostic techniques and treatment approaches in MS patients.

Abstract

Complex mechanisms of thymus functioning affect the structural matrix, contributing to the gradual accumulation of genetic mutations, changes in gene expression and premature immunosenescence. The study of early thymic migrants (RTE) is necessary to identify possible diagnostic biomarkers and potential checkpoints of autoimmune diseases. The object of the study were peripheral blood samples of patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), psoriasis (PS) and healthy donors. The aim of the study was to assess the ratio of recently migrated cells from the thymus and naive T-regulatory cells in the periphery in health and autoimmune pathology. The relative number of recent thymic migrants CD4+CD45RA+CD31+ (RTE) and the number of Foxp3+ T-regulatory cells (Treg) among them were determined by flow cytofluorimetry. The number of proliferating cells was determined by the intracellular Ki-67 content. The analysis showed that the number of RTE was reduced in the group of patients with RA and patients with PsA relative to the donor group (17.3%, 18.6% vs. 23.6%) and did not change significantly in patients with psoriasis. There were no significant differences between donors and patients with AID in the number of proliferating RTE and Tregs. The level of proliferation of T-regulatory cells in patients with psoriatic pathology was comparable to donor values, and in RA there was a tendency to an increase. In patients with RA, the number of proliferating naive Foxp3+ Tregs was significantly higher than the number of proliferating RTE (15.8% vs 3.1%, p<0.05, respectively). A decrease in the relative number of RTE  in AID may be associated with the activation of T lymphocytes and an increase in the proportion of central memory T cells. The number of Tregs among RTE and the level of their proliferation in patients with psoriatic pathology, indicate the absence of disturbances in the generation of T-reg in the thymus. The ambiguous results obtained in patients with RA, require additional confirmation on a larger sample of patients.

Cyclophosphamide is a widely used anticancer and immunosuppressive drug. Myelodepression and leukopenia is among its negative side effects. Natural and synthetic substances are able to reduce such negative effects. Protective effects of antioxidants on bone marrow are known when used together with cyclophosphamide. Plant and animal active peptides are also of interest due to their low toxicity, broad-spectrum biological activity. The Bursanatal preparation, due to presence of active peptides, growth factors, cytokines, antioxidants is also a promising immunomodulator, which previously showed a positive effect on immune response to infectious diseases in farm animals. The aim of this study was to investigate the effect of the Bursanatal on immunological parameters in C57Bl/6 mice with cyclophosphamide-induced immunosuppression. The extract from bursa Fabricii was obtained from chickens aged 35-42 days by homogenization and subsequent removal of the heat-labile fraction. The final extract contains biologically active substances with molecular mass of 1 to 10 kDa. The immunodeficient condition was induced with single injection of cyclophosphamide (200 mg/kg body weight). The experimental group of mice received bursa extract intraperitoneally for 7 days (0.1 mL/20 mg body mass). Seven days later, the mice were weighted, and blood counts were performed using hematological analyzer and flow cytometry (T and B lymphocyte subpopulations). The cyclophosphamide-treated mice developed B cell lymphopenia. After exposure to the bioorganocomplex, an increase in B cell counts was observed in peripheral blood compared to the intact controls. A changed ratio of T lymphocyte subpopulations in peripheral blood was also observed. The obtained data allow to suggest the absence of a pronounced immunotoxic effect of the Bursanatal. Moreover, the active components of the extract may be considered good candidates for alternative adjuvant chemotherapy in order to reduce immunotoxicity.

Cardiovascular diseases are one of the major global health problems with high prevalence and mortality rates. Complex intercellular communications supported by circulating exosomes, recognized as important participants in the immunopathogenesis of atherosclerosis and coronary heart disease, thus playing a crucial role in pathogenesis and progression of cardiovascular diseases. Presuming tetraspanins (CD63 and CD81) being widely recognized as exosomal markers, the purpose of our study was to determine and evaluate the time dynamics of serum exosomal tetraspanins CD63 and CD81 production on 1^st and 7^th days after acute myocardial infarction. The study included 40 patients with acute myocardial infarction (AMI) aged 54.29±5.45 years and 10 healthy persons, matched for age and gender. Two types of tetraspanin dynamics were revealed following AMI in acute ischemic process in the myocardium. Type 1 is characterized by initially low values of tetraspanin CD63, compared to healthy individuals, and is accompanied by an increased production/release of exosomal CD63 on day 7; type 2 is characterized by higher CD63 values, exceeding reference values on day 1 after AMI, with its decrease by day 7. Our correlation analysis of tetraspanin CD63 allowed us to establish links with age, cholesterol, LDL, triglycerides and the number of platelets and leukocytes. The CD81 level in blood serum of AMI patients was significantly lower than in healthy individuals. The identified features of the production dynamics allowed us to classify patients by distinct response types: (1) with increase in serum exosomal CD81 and subsequent achievement of the target tetraspanin level typical for healthy individuals; (2) with a decreased concentration against initial level, associated with higher frequency of adverse cardiovascular events. The correlation analysis of serum CD81 allowed us to establish correlations with leukocyte counts, erythrocyte sedimentation rate and obesity grade. Exosomal profile of circulating CD63 and CD81 in individuals with AMI differs quantitatively from healthy subjects, being characterized by different types of dynamics of tetraspanin production during the first week of myocardial infarction.

The aim of the work was to assess differences in clinical pattern and immunological status in patients with acute coronary syndrome (ACS) and Post-COVID syndrome (PCS), taking into account the level of TREC in the peripheral blood. A total of 32 patients aged 40 to 65 years with ACS and a history of COVID-19 from 6 to 18 months were examined. All patients underwent coronary angiography and stenting of the coronary arteries. To determine TREC levels in peripheral blood, the TREC/KREC-AMP PS reagent kit (Pasteur Research Institute, St. Petersburg) was used. To determine the studied subpopulations of peripheral blood lymphocytes, Beckman Coulter (USA) reagents – TetraChrome were used. The analysis of samples was studied with a Navios™ flow cytometer (Beckman Coulter, USA). Among patients with ACS and PCS, the TREC content was determined in 32 patients, including 28 with unstable angina and 3 with acute myocardial infarction without ST segment elevation. The patients were divided into groups depending on the TREC content: (1) with a reduced TREC level (1^st group) and with normal index values (2^nd group). One should note that only one patient from this group had reduced KREC values, the rest being within normal range. Therefore, we did not find any effect of KREC on clinical and immunological features of subjects with ACS and SCS. Individuals with reduced TREC levels had a lower relative and absolute number of T-helper cells (p < 0.01), and their immunoregulatory index was lower (p < 0.01). At the same time, an increase in relative (p < 0.01) and absolute numbers of T cytotoxic cells (p < 0.05), as well as percentage of T-NK lymphocytes (p < 0.05) was noted in this group of patients. Also, in patients from the 1^st group, we have seen a tendency to increase in NK lymphocyte numbers and decrease in B lymphocytes (CD3^-CD19⁺). A low-TREC subgroup of patients with ACS and PCS showed a more severe clinical course. However, due to limited group of patients, further study of such relations is planned with a larger set of clinical cases. Detection of immune disorders using the mentioned screening methods requires novel approaches to immunocorrection of these disorders which are currently discussed by cardiologists.

The corneal graft rejection, especially in patients from the “high risk” group, is a complex immunological process that remains an urgent problem in ophthalmology. The cornea, despite its immunological privilege, loses its protective barriers under certain conditions (vascularization, inflammation), which leads to the development of immune reaction against the transplant. The key mechanisms of rejection include activation of T lymphocytes (CD4⁺ and CD8⁺), as well as an imbalance between effector and regulatory immune cells. Modern methods of immunological monitoring, including analysis of T cell populations, make it possible to detect signs of rejection in a timely manner and adjust therapy to improve long-term transplant results. The aim of our study was to conduct a comparative cytometric analysis of the population and subpopulation composition of blood lymphocytes in patients after end-to-end (penetrating) keratoplasty. The study involved 46 patients who underwent penetrating keratoplasty, being divided into two subgroups: those with transplant rejection (n = 25) and those with successful engraftment (n = 21), as well as a control group of 21 healthy volunteers. The immunological analysis included venous blood sampling and quantitative determination of lymphocyte subpopulations by flow cytometry using a Navios cytofluorimeter (Beckman Coulter, USA) and markers of CD45⁺ and CD46⁺ cell populations. Key populations of lymphocytes, including T helper cells, cytotoxic T lymphocytes, NK cells, B lymphocytes, and activated T cells, were studied to identify differences in the immune status of patients. Comparative cytometric analysis of the population and subpopulation composition of peripheral blood lymphocytes in “high-risk” patients with graft rejection showed a number of significant changes manifesting as an increased total number of T lymphocytes, T helper cells, T cytotoxic, T lymphocytes with markers of early and late activation, thus suggesting the key role of T cell-mediated immunity in development of late cellular rejection reactions. The data obtained suggest involvement of systemic cellular mechanisms into rejection of the native corneal allograft, presuming a need for a more detailed study of the T cell response of immune system in this condition. Cytometric assessment of subpopulations of immunocytes makes it possible to identify early signs of immune activation associated with rejection and opens up new opportunities for the development of personalized and effective treatment strategies aimed at improving the transplant outcomes.

Inflammatory conditions of the maxillofacial area and oral mucosa are a dominating syndrome in patients with immunodeficiencies. The purpose of our study was to assess the incidence of inflammatory diseases of the dental system in patients with congenital immune deficiencies. The study group of patients observed at Sverdlovsk Regional Clinical Hospital No. 1 and Regional Children’s Clinical Hospital (Yekaterinburg) included 64 persons with primary immunodeficiencies including combined immunodeficiencies, deficient antibody production, auto-inflammatory disorders, deficient phagocyte function, immune dysregulation conditions, complement deficiencies, and a case of non-specified immune deficiency. Lymphadenitis of the maxillofacial region, recurrent stomatitis, ulcers and cheilitis are characteristic of all the studied groups of patients, except for the group with complement deficiency. The diagnosis of candidiasis was identified in the two groups: classified as “combined immune deficiency” (4.2% from the subgroup), “phagocyte deficiency” (50% from the subgroup). The similar incidence of maxillary sinusitis was documented in the following patients: “antibody defects” (46% from the subgroup), “autoinflammatory disorders” (13% of cases); maxillofacial abscesses and phlegmons were diagnosed in “autoinflammatory disorders” (13%), “phagocyte defects” (10% from the subgroup). The highest percentage of inflammatory dental diseases, such as cheilitis (36% from the entire study group), stomatitis (33% from the entire study group), and maxillofacial lymphadenitis (31% from the entire study group), was registered. The maximum spectrum of the mentioned inflammatory diseases was diagnosed in patients with auto-inflammatory disorders and phagocyte defects. At the same time, the largest number of people from these groups (60% and 70%, respectively) suffered with recurrent stomatitis and ulcers. Inflammatory dental diseases were not detected in a single patient diagnosed with complement deficiency. The following common dental manifestations were identified in patients with congenital immune defects: lymphadenitis of maxillofacial region, cheilitis, stomatitis and ulcers. This data would be useful for proper patient routing.

Adequate adaptation and functioning in a distinct environment proceed with integration of the nervous, endocrine and immune systems. Assessing the changes of immune response formed under disturbed psychoemotional state which may serve as predictors of emerging immune pathology is of particular interest. These studies may find the greatest practical application when observing a cohort of young, practically healthy adults during their professional development. The aim of our work was to reveal the adaptive resources of immune system among military medical students in the course of the educational process. The survey included students of the military training center (MTC) during their 1^st (18 persons), 3^rd (n = (31), and 6^th academic year (n = 34), assigned to the 1^st health group. Psychological testing was carried out using the method of Ch.D. Spielberger (Russian adaptation, Yu.L. Khanin) applied for differential measuring of situational and personal anxiety degree accepted as an index of resistance to stress factors. To assess the features of socio-psychological adaptation to learning environment, we used the questionnaire by K. Rogers and R. Diamond, calculating the integral adaptation index (IAI). The immune status was assessed using standard methodology in ordwer to evaluate the systemic and functional characteristics of innate and adaptive immune response. The hormonal pattern in blood serum (testosterone, cortisol, TSH, total T3, free T4) was estimated by the ELISA method. The integral IAI coefficient reflected a gradual improvement in adaptability to the study environment. Complete adaptation was revealed only in 40% of first-year students; in 80% of third-year students, and in 100% in the sixth year. Comparison of immune parameters with reference values of practically healthy people showed compliance in all examined groups by most criteria except of the first-year students, where a decrease in the number of cytolytically active forms of natural killers was revealed: % Gr⁺CD16⁺ (min-max) = 1-10 versus 3-15 in controls, as well as a decreased proportion of TLR4-expressing monocytes: CD14⁺CD284⁺ (min-max) = 5-22%, versus 10-25% in controls). Statistically significant differences in hormone profile were noted between the observed groups, i.e., a predominance of testosterone and triiodothyronine levels in first-year students, whereas cortisol, thyroxine and thyroid-stimulating hormone levels were at similar level in students from different years. The time period of psychological adaptation to educational process at a Medical University is less successful for the first-year MTC students in comparison with other observation periods: in this group we revealed a decrease in immune indices responsible for the primary immune response, thus forming pre-requisites for the development of clinically sound immune dysfunction.

Earlier, we have revealed a novel factor regulating autoreactivity called regulatory rheumatoid factor (regRF), which is represented by a population of anti-idiotypic antibodies that have a common paratope specific to the PD1 molecule. RegRF exerts cytotoxic effect on activated PD-1⁺CD4 T lymphocytes and controls the lymphocyte expansion. Its production during the induction period prevents experimental autoimmune diseases in rats. The association between regRF and resistance to these disorders suggests that regRF stimulation may be an effective treatment of autoimmune diseases. Sjögren’s syndrome (SS) is an autoimmune disease that may accompany other autoimmune diseases or occur independently. Salivary gland (SG) lesions and lymphocytopenia may develop in SS. It is not known whether the regRF is a resistance factor to SS, and if the regRF stimulation may be used to treat this condition. The aim of this study was to clarify the role of regRF in ensuring resistance to Sjogrens syndrome in rats. SS was induced in Wistar rats by immunization with proteins isolated from murine SG. Blood samples were taken from the caudal vein each week before and after the immunization. Histological analysis of submandibular SG tissue was performed 12 weeks after the initial immunization. Autoantibodies to CD4 were detected in serum by ELISA; regRF levels were measured by agglutination of IgG-coated erythrocytes; CD3⁺, CD4⁺ and CD8⁺ lymphocyte counts were determined by flow cytometry in blood samples. 40% of rats immunized with mouse SG proteins, have developed SG lesions typical of sialoadenitis occurring in Sjogren’s syndrome. 50% of rats exhibited chronic lymphocytopenia (CD3, CD4 and CD8 cell populations) in response to immunization with mouse SG proteins. In rats with CD4 lymphocytopenia, no autoantibodies to CD4 have been found. An association has been found between a high level of regRF on day 7 following immunization with mouse SG proteins and resistance to sialadenitis in rats. However, lymphocytopenia did not depend on regRF production during induction of SS. Thus, regulatory rheumatoid factor is a preventive factor for sialoadenitis, but not to lymphocytopenia in rat model of Sjogren’s syndrome.

Type 2 diabetes (T2D) is a chronic disease with a large number of severe complications. The number of T2D patients continues to grow worldwide. Hence, development of new prevention and treatment tools are extremely relevant. Oxidative stress caused by hyperglycemia is one of the main factors of organ damage and dysfunction in T2D. Due to close involvement of the immune system in pathogenesis of diabetes and its complications, the opportunity of influencing antioxidant defense system in immunopoietic system, especially, spleen, presents sufficient interest. The liver, which integrates all types of metabolism, along with immune organs, contributes to the T2D pathogenesis, being among its target organs. Red clover (Trifolium pratense) is of interest as an economic and accessible source of antioxidants. The aim of our work was to evaluate the effect of red clover isoflavones on the antioxidant defense system in blood, spleen and liver of rats with experimental diabetes. Sexually mature male rats with a streptozotocin-nicotinamide model of T2D were orally administered aqueous extracts of isoflavones, obtained by “green technology” methods using deep natural eutectic solvents, at the doses of 300 and 600 mg/kg. The animals were treated over one month, three times a week, Glucose levels, relative content of glycated hemoglobin, leukocyte numbers and differential blood counts were measured in blood. The activity of antioxidant enzymes (catalase and superoxide dismutase), malondialdehyde production (a lipid peroxidation product), and contents of reduced glutathione, an endogenous antioxidant, were determined in blood, liver and spleen by biochemical techniques. Administration of red clover isoflavone extracts (Trifolium pratense) caused reduction of hyperglycemia and restored the reduced number of monocytes and granulocytes in blood in diabetic rats. It also caused normalization of catalase activity in liver and superoxide dismutase activity in spleen, the malondialdehyde levels in spleen and liver, and reduced glutathione contents in spleen, which was changed in diabetic rats, to healthy control values, regardless of the dose. Isoflavone extracts from red clover flower (Trifolium pratense) attenuate hyperglycemia and reduce oxidative stress in the organs of rats with experimental T2D. Isoflavone extracts have an immunopharmacological effect, by influencing the parameters of lipid peroxidation-antioxidant defense system in the spleen.

The elderly persons are a high-risk group for the development of diabetes mellitus (DM). Both aging and DM can influence hematological parameters related to key physiological and pathological processes. The additive effect of aging and diabetes may exacerbate alterations in general blood counts, thus leading to more pronounced hematological changes and an increased risk of complications. To mitigate pathological processes associated with DM, antioxidants and anti-inflammatory drugs are widely utilized. However, the effects of certain compounds, such as alpha-lipoic acid (ALA) and sodium aminodihydrophthalazinedione (APG), on blood parameters remain scarcely investigated. The aim of this study was to evaluate and compare the effects of ALA and APG on biochemical and hematological parameters in aged rats with alloxan-induced DM. The study was conducted in 35 male Wistar rats, which were divided into five groups: 1 – young (5 mo) intact animals, 2 – aged (18 mo) intact animals, 3 – aged rats with DM, 4 – aged rats with DM treated with ALA, 5 – aged rats with DM treated with APG. Experimental diabetes was induced by intraperitoneal administration of alloxan. ALA was administered daily intramuscularly to diabetic animals at a dose of 4 mg/100 g of body weight for 30 days. APG was administered intramuscularly at a dose of 2 mg/100 g of body weight at the following regimen: daily for 10 days, daily for the next 5 days, and every 3^rd day for the remaining 15 days. On day 60, blood samples were collected to assess glycemic levels and hematological parameters. Biochemical analysis revealed that both ALA and APG administration corrected metabolic disturbances in diabetic rats in similar manner, significantly reducing blood glucose levels. Hematological analysis showed an age-associated increase in size scatter of red blood cell (RBC). Administration of ALA led to an increase in mean corpuscular volume and mean corpuscular Hb, but a decrease in mean corpuscular Hb concentration. In contrast, APG significantly increased RBC counts, hemoglobin concentration, and hematocrit. Both agents significantly reduced the relative lymphocyte count and increased the relative granulocyte count. ALA and APG also reduced total platelet count, mean platelet volume, and size scatter of platelets, while increasing the ‘plateletcrit’. Administration of both ALA and APG alleviated hyperglycemia in rats with alloxan-induced diabetes by lowering blood glucose levels. Both compounds exerted similar effects upon white blood cell and platelet parameters, however, they differed in their ability to correct RBC indices in diabetic rats.