Common Ɣ-chain cytokine receptors as functional phenotype markers of PD-1and TIM-3-positive T cells in multiple myeloma

T cells expressing checkpoint receptors PD-1, TIM-3 etc., are potential targets for monoclonal antibody immunotherapy in multiple myeloma (MM). However, cell compartment includes different subsets, and their dysregulation following anti-checkpoint therapy can lead to the development of adverse events. The aim this study was evaluate activation markers – homeostatic cytokine transcription factors expressed by PD-1and TIM-3-positive cells. Material Methods. Relative counts circulating PD-1and/or negative common ɣ-chain CD25, CD122, CD127, phosphorylated STAT5, factor EOMES associated with exhaustion were studied using flow cytometry 17 healthy donors, 22 MM patients remission 7 progressive disease. Results. PD-1 and/or inhibitory consisted CD25+EOMESactivated cells, CD4+CD25+CD127-FOXP3+ regulatory (Treg), CD4+CD25-EOMES+ dysfunctional CD25+ from donors patients, regardless expression receptors, EOMES-negative. No such association found CD122 CD127 receptors. is a marker CD4+ but not CD8+ which it more activation. proportion Tregs among PD-1+ TIM-3+ relatively low. A higher content population may indicate predominant involvement control proliferation mature under lymphopenic conditions, while be regulation through receptor. levels activated, dysfunctional, potentially used predict safety efficacy targeted immunotherapy.