BATF regulates the expression of Nfil3, Wnt10a and miR155hg for efficient induction of antibody class switch recombination in mice

BATF functions in T cells and Bcells to control the host response to antigen and promote the production of class switched immunoglobulins. In this study, we demonstrate that BATF expression increases rapidly, and transiently, following Bcell stimulation and use an inducible murine model of BATF deletion to show that this induction is necessary, and sufficient, for immunoglobulin (Ig) class switch recombination (CSR). We examine two genes (Nfil3 and miR155gh) that are positively regulated, and one gene (Wnt10a) that is negatively regulated by BATF during CSR. These genes play essential roles in CSR and each impacts the expression and/or function of the others. Our observations allow these targets of BATF regulation to be positioned in a network upstream of the activation of germline transcripts (GLT) from the IgH locus and of transcriptional activation of Aicda - the gene encoding the enzyme directing Ig gene rearrangements. This work extends the knowledge of the molecular control of CSR and, importantly,positionsthe induction and function of BATFas an early eventin this process.