The system influence of allogeneic adipose tissue derived mesenchymal stem cells on the functional state of immune organs

The studies were conducted on 2–3-months-old males of mice weighing 20–24 g. Оur work was to study the functional state of the organs of the immune system of C57Bl/6 mice after introduction of allogeneic MSCs of adipose tissue origin. Obtaining and cultivating of MSCs were carried out in a sterile laminar box with compliance of conditions of asepsis and antiseptics. C57Bl/6 mice adipose tissue cultured in a CO2 incubator at 37 °C and 5% CO2  in DMEM with 10–15% of fetal bovine serum, 1% of antibiotic-antimycotic solution (Sigma-Aldrich, USA). The following groups of animals were formed: 1 group – intact (control group); 2 group – animals, to whom 0.5 ml of 0.9% NaCl solution (placebo) were injected into the caudal vein; 3 group – animals, to whom were injected 104 of allogeneic MSCs from adipose tissue in 0.5 ml of phosphate buffer solution into the caudal vein. The weight index, content of lymphoid cells of thymus and spleen in C57Bl/6 mice investigated after the introduction of MSCs on 7, 18 and 25 days. To assess the content of lymphocytes in lymphoid organs, the latter were weighed. Whole thymus and 50 mg of spleen were triturated and filtered through the kapron tissue. After that, the tissue homogenate was applied to the gradient of ficoll-urografin (density 1.077) in a ratio of 3:2. The test tubes were centrifuged at a rate of 1500 rpm for 30-40 minutes. After centrifugation the layer of lymphocytes which was above the gradient was collected by a Pasteur pipette and washed twice with an arbitrary amount of Hanks' solution by centrifugation at a rate of 1500 for 10 minutes. 1 ml of Hanks's solution was added to lymphocytes after washing. Lymphocytes were counted in the Goryaev chamber. Calculation of the cells of lymphoid organs was performed on 1 mg of tissue. The administration of allogenic adipose derived mesenchymal stem cells affects on the central and peripheral organs of the immune system. Administration of allogenic adipose derived mesenchymal stem cells cause a significant increase in the content of lymphoid cells in the thymus at 7, 18 and 25 days by 71, 57 and 53% respectively (P < 0.05) compared to the control. Weight index of the thymus directly correlates with the content of lymphoid cells and its value was r = 0.57, P < 0.01 on 7 day  and 18 day r = 0.50, P < 0.05. Quantity lymphoid cells in the spleen significant increase at the 7 and 18 days of the immune response by 33 and 19%, respectively (P < 0.01, P < 0.05) compared to the control under administration of allogenic adipose derived mesenchymal stem cells. On the 25th day of experience, the content of lymphoid cells in spleen and spleen index values return to normal. Weight index of the spleen directly correlates with the content of lymphoid cells – r = 0.91–0.94 (P < 0.001).