CYTOKINE-INDUCED REGULATION OF MATURATION, DIFFERENTIATION, AND APOPTOTIC DEATH OF IMMUNE MEMORY T-LYMPHOCYTES

To maintain the normal state of the immune system, the processes of cell proliferation must be strictly regulated and balanced by the processes of apoptotic death to prevent the development of autoimmune and neoplastic reactions. T-lymphocytes of immune memory are under strict control from the immune system. The role of γc-cytokines (IL-2, IL-7, and IL-15) in the regulation of maturation, differentiation, and apoptotic death of memory T-lymphocytes under in vitro cultivation conditions was evaluated. The study revealed the ability of γc-cytokines to increase the content of CD3+HLA-DR+CD95+ T cells in the effector populations of immune memory cytotoxic lymphocytes, which may indicate the processes of cell differentiation and maturation under the influence of γc-cytokines. The authors also showed that in CD3+CD4+CD45RO+ T-lymphocytes have a relative resistance to the action of γc-cytokines, in comparison with cytotoxic CD45RO+ T-cells. Thus, maintaining homeostatic concentrations of γc-cytokines plays an important role in maintaining the normal functioning of the immune system by maintaining the balance of homeostatic proliferation and apoptotic death. We also noted that cytokine imbalance contributes to an increase in the surface expression of late activation molecules (HLA-DR) and apoptosis (CD95), which is necessary to control excessive proliferation of lymphocytes, and, ultimately, prevents the breakdown of immune tolerance mechanisms and the development of hyperproliferative pathologies of the immune system.