IFN-γ and IL-21 Double Producing T Cells Are Bcl6-Independent and Survive into the Memory Phase in Plasmodium chabaudi Infection

摘要: CD4 T cells are required to fight malaria infection by promoting both phagocytic activity and B cell responses for parasite clearance. In Plasmodium chabaudi infection, one specific subset generates anti-parasitic IFN-γ the antibody-promoting cytokine, IL-21. To determine lineage of these multifunctional cells, we followed IFN-γ+ effector (Teff) into memory phase using Ifng-reporter mice. While Ifng+ Teff expanded, level Th1 lineage-determining transcription factor T-bet only peaked briefly. also co-express ICOS, area homing molecule CXCR5, other Tfh lineage-associated molecules including Bcl6, germinal center (GC) follicular helper (Tfh) differentiation. Because Bcl6 co-localize nucleus Teff, hypothesized that controls Tfh-like phenotype in P. infection. We first transferred Bcl6-deficient wildtype hosts. did not develop GC Tfh, but they still generated CXCR5+ IL-21+ IL-10+ suggesting this predominant population is Tfh-lineage. IL-10 deficient mice, which have increased expression, demonstrated expansion a former. phase, all produced IL-21, small percentage highly proliferative maintained T-bethi phenotype. chronic serum correlates with protection, our observation suggests cellular division. summary, found strictly derived during provide host survival advantage when facing well-equipped pathogen, therefore, understanding pivotal players will aid rational design an effective vaccine.