Influence of glycodelin on morphofunctional state of secondary immune organs in experimental model of allogeneic transplantation

Glycodelin (PP14, PAEP, alpha-2-microglobulin, dimeric glycoprotein with a molecular weight of 42 to 56 kDa) is a marker of reproductive tissue receptivity. Immunoregulatory potential of glycodelin allows us to consider it among key factors that promote maternal immune tolerance to the developing embryo. In general, glycodelin has prospects for use in biomedicine as a biopharmaceutical to treat post-transplant complications. This work aimed to study the effect of glycodelin on morpho-functional state of the secondary organs of immune response in the course of in vivo experiment during allogeneic transplantation of bone marrow cell suspension to Wistar rats. The experiment was performed in white male Wistar rats aged 2-3 months (body mass, 250 g). The animals were kept at the Perm State National Research University animal clinic under GOST 33216-2014 “Rules for working with laboratory rodents and rabbits”. The animals were sacrificed on the 3^rd, 7^th, 14^th, and 21^st days according to international rules for working with experimental animals. In the control group, animals (n = 6) were injected once with a suspension of camptothecin-treated bone marrow cells; in experimental group, the animals (n = 12) were injected with a bone marrow cells in combination with glycodelin administered 4 times.

We used recombinant glycodelin (MyBioSource, Germany), which was administered to the animals at a concentration corresponding to pregnancy state (0.75 μg/mL). Intraperitoneal injection of bone marrow cells simultaneously with glycodelin over the terms of experiment (21 days) showed that allogeneic transplantation caused hyperplasia of spleen and lymph nodes. In the functional zones of organs, proliferation and differentiation of immune cells developed. Injection of glycodelin at the early stages of experiment (3-7 days) caused an increase in proliferative processes in the organs of both T- and B-dependent immunity. Moreover, there were no signs of inflammation and apoptotic cell death in the organs. Since the 14^th day of the experiment, eosinophilic infiltration of the organs was evident, being an indirect positive sign of response to the transplanted cells. By the end of study, differentiation processes dominated over proliferation in the organs. Thus, glycodelin stabilizes proliferative processes and promotes emergence of a new cell generation, thus supporting host response to the transplant. Apparently, glycodelin can participate in development of adaptive mechanism in secondary organs of immune system.