Abstract
Studies on the mechanisms of activation of cytotoxic lymphocyte subpopulations are an important research direction in modern immunology. This study provides a detailed analysis of the effect of Tag7 (PGRP-S, PGLYRP1) on the development of lymphocyte subpopulations cytotoxic against MHC-negative tumor cells in a pool of peripheral blood mononuclear cells (PBMCs). The results show that Tag7 can bind to the TREM-1 receptor on the surfaces of monocytes, thereby triggering the expression of mRNA TNFα and IFNγ. The appearance of these cytokines in conditioned medium leads to IL-2 cytokine secretion by CD3+CD4+ lymphocytes. In turn, IL-2 facilitates unspecific activation of three cytotoxic cell subpopulations in the PBMC pool: NK (CD16+CD56+), CD3+CD4+ and CD3+CD8+. These subpopulations appear after a certain period of incubation with Tag7 and show toxicity against tumor cells.