Comparison of transcriptional profiles of CD62L+ and CD62L- subsets of in vivo primed CD44hiCD4+ T cells by exposure to ovalbumin plus papain

Memory type 2 CD4+ T helper (Th2) cells play critical roles in allergic asthma, but their generation and maintenance remain poorly understood. Specially, roles of conventional dendritic cells (cDCs), including CD11b+CD103- cDC2s and CD11b-CD103+ cDC1s, in this process are still undefined. Here, we report that fate decision of memory Th2 cells was dictated by cDC subsets at priming stage. To be specific, temporary depletion of CD103+ cDC1s during priming promoted the generation of allergen-specific circulating memory Th2 cells in exposure to ovalbumin plus papain, suggesting that precursors of memory Th2 cells emerged at priming stage. Subsequent data revealed that activated CD44hiCD62L+CD4+ T cells, which were elevated by cDC1 depletion during priming, exhibited memory-precursor-like transcriptional and functional properties. Taken together, CD103+ cDC1s reduced number of CD62L+ memory precursors, and thus restrained generation of memory Th2 cells. Naïve CD45.1+CD4+OT-II T cells (specifically recognize ovalbumin), sorted from un-treated CD45.1×OT-II mice, were injected into C57BL/6 (WT) and Batf3-/- mice (CD45.2+), and recipients were immunized with ovalbumin plus papain 24 h after injection. CD62L+ and CD62L- subsets of activated CD44hiCD45.1+T cells were sorted from mediastinal lymph nodes of WT and Batf3-/- mice 5 days after immunization. Naïve CD45.1+CD4+OT-II T cells were used as control. Three independent replicates were prepared for each cell subset.