Effects on cellular immunity caused by intravenous infusion of allogenic rhesus mesenchymal stem cells

Abstract

Objective To study the changes of cellular immunity caused by intravenous infusion of allogenic rhesus mesenchymal stem cells (MSCs). Methods MSCs were isolated and cultured. Then the immunomodulatory effects after MSCs infusion were evaluated by means of peripheral blood counts, mixed lymphocyte reaction (MLR) and analysis of lymphocytic subgroup. Results MSCs of rehsus were successfully cultivated. No acute toxicities or GVHD were observed in recipients. No obvious changes of peripheral blood counts were present. Recipients A2, A3, A4 were administered with MSC by 4.0 ×105/kg, 1.0 ×106/kg, 2.0×106/kg respectively and relative reaction (RR) of MLR decreased 14 days post MSCs infusion: from 46±2.6 ％to 40.4±1.73 ％ (F =10.19, P =0.023), from (40.9±2.3) ％ to (33±2.1) ％ (F =2.593, P =0.013), from 48.3±2.0 ％ to 39±1.0 ％ (F =28.431, P =0.003) respectively. The decrease degree (ARR) was positively related to the amount of MSCs(F =27.413, P =0.038). RR was restored within 30 days post MSCs infusion. After MSCs infusion, CD3+ CD3+CD4+ and CD3+CD8+ T-lymphocytes decreased in recipient A4, who was administered with the largest number of MSCs, and restored within 30 days. Conclusion MSCs infusion without any other treatment could temporarily inhibit immunity of T lymphocytes in MLR and the immunity inhibition was positively related to the amount of MSCs. The specific immunological characteristics of MSCs were demonstrated with extensive prospect in clinical research. Key words: Mesenchymal stem cells; Macaca; Immunity