scRNA-seq of day 32 p.i. GC B cells induced by experimental Plasmodium infection following the inducible deletion of IL-21 from CD4 T cells on day 16-18

IL-21 is critical for initiating humoral immune responses, but whether sustained IL-21 production by T follicular helper cells regulates the quality or output of memory B cells and plasma cells during an established germinal center response is unknown. Here, we applied scRNA and approaches to determine the heterogeneity of germinal center B cells from Plasmodium infected mice with or without truncated IL-21 expression. Overall design: Mice were infected with 1 million Plasmodium yoelii parasitized red blood cells and subsequently treated with tamoxifen on days 16, 17 and 18 p.i. to induce the deletion of Il21 from the CD4 T cell compartment. Comparator cells derive from Plasmodium infected and tamoxifen treated mice bearing the conditional alleles of Il21 but lacking the Cd4-ERT2/Cre transgene. On day 32 p.i., CD95+ GL-7+CD19+B220+ cells were FACS-sorted from mice (4 donor mice/genotype) and loaded on the Chromium Controller (10x Genomics) Single-cell RNA-seq libraries were prepared using the Chromium Single Cell 3' v2 Reagent Kit (10x Genomics) according to the manufacturer's protocol.