RNA-sequencing of pre-GC B cells helped by CD4-CrexBcl6fl/+ or CD4-Cre OT-II T cells

We analyzed transcriptome differences of antigen-specific pre-GC B cells. We transferred wildtype (CD4-Cre) or BCL6-insufficient (CD4-CrexBcl6fl/+) OT-II T cells into SAP-deficient mice and immunized these mice with NP-OVA. By day 3 post immunization, we sort-purified NP-binding B cells that were developing into GCs and conducted RNA-seq analyses of their transcriptome. NP+IgDlowB220+ pre-GC B cells from recipients of the same group were pooled to sort-purify 4 200-cell repeats. Using a gene expression signature induced by CD40 signaling in B cells for enrichment analysis, we found such CD40-induced gene set expression was significantly deprived in those NP-binding B cells helped by CD4-Cre´Bcl6fl/+ T cells. These data suggest BCL6 insufficiency in T cells leads to impaired CD40L signaling to B cells. Overall design: Transcriptome analysis of pre-GC B cells helped by CD4-CrexBcl6fl/+ or CD4-Cre OT-II T cells 3 days after activation in vivo by NP-OVA immunization.