α-GalCer administration expands virtual memory CD8 +T cells through IL-4 secretion

Abstract Virtual memory CD8 +T (CD8 VM) cells, a unique subset of cells bearing phenotypes, exist in naïve and even germ-free mice. Distinct from the conventional T VMcells are antigen-inexperienced but able to respond quickly cognate antigen-independent manner, thus could provide broad range innate-like protective effects. Our previous study showed that be expanded by type 2/interleukin-4 (IL-4) responses. Thus, we used α-galactosylceramide (α-GalCer) selectively activate invariant natural killer (iNKT) create 2/IL-4 response, which turn induced robust VMcell expansion. We further demonstrated CD1d molecule NKT were necessary for α-GalCer-induced expansion, expansion was only partially dependent on IL-4 this scenario. It remains unclear how induces what other cytokine(s) may contribute IL-4-independent upon α-GalCer treatment. Among multiple cytokines treatment, found addition IL-4, IL-15 I interferons (IFNs), have been reported participate development VMcells, elevated response treatment vivo. not IFNs drove proliferation vitro. Thus. speculated one factors involves IL-15. currently testing hypothesis. Taken together, our results suggested activation iNKT expands pool through production, regulate ability protection. Supported grants MOST (109-2320-B-002-074-MY3), NHRI (EX110/111-11033SI) NTU (111L7829), Taiwan