Evaluation of the effect of proinflammatory cytokines in virtual memory CD8+ T cells

LIDON, NICOLÁS LEONEL; SAVID-FRONTERA, CONSTANZA; VIANO, MARIA ESTEFANIA; FONTAINE, QUENTIN; RODRIGUEZ-GALAN, MARIA CECILIA

Mar del Plata

Congreso; Reunión anual de sociedades de biociencias SAIC. SAI. SAFIS; 2022

Virtual memory CD8+ T cells (TVM) are a subset of T cells with a memory phenotype (CD44hi and CD122hi) without previous antigen encounter. TVM can be distinguished from conventional memory T cells (TMEM) by their low expression of CD49d. We evaluated the role of different cytokines reported as important for both survival and functionality of TVM, such as IL-12, IL-18, IL-15, IL-4 and IFNg. To determine the effect of IL-15 on TVM and TMEM survival, in vitro assayswith variations in IL-15 concentrations demonstrated that the lowest IL-15 concentration (5ng/ml, IL-15lo) increased the percentage of TMEM, but this effect is not seen with the highest IL-15 concentration (20ng/ml, IL-15hi). Moreover, double stimulation with IL-15hi and plate-coated anti-CD3 induced a significant decrease in the number of TMEM. For TVM, both IL-15hi and the IL-15hi+anti-CD3 conditions induced the greatest increases in the percentage of this population.Regarding the possible functional activity of TVM, Fura-2 assays show that cells from lymph nodes in contact with KPC tumor cells induced higher intracellular calcium mobilization when they comefrom animals treated in vivo with IL-12 and IL-18 (enriched in TVM) compared to same cells from control mice (p