Division-Specific Accessibility Program of B cell Differentiation

B cell differentiation occurs over multiple cellular divisions and involves a switch in transcriptional programs that allows for antibody secretion. The transcription factors that drive this process have been studied but the epigenetic mechanisms and sites these factors function at are not well understood. Here we investigated the distinct changes in chromatin accessibility that occured at distinct cellular divisions during in vivo B cell differentiation. Congenically marked B cells were CFSE labelled and adoptively transferred into uMT mice that lack B cells. One day post-transfer, mice were innoculated with LPS and transferred cells isolated three days later. Using CFSE and the plasma cell marker CD138, cells representing undivided (Div0) or had progressed through 1, 3, or 5 divisions (Div 1, 3, 5) and not aquired CD138, and cells that had gone through at least 8 divisions (Div8+) and acquired CD138 were isolated by FACS. ATAC-seq was performed on the isolated cells.