B cell expression patterns before and after Nippostrongylus brasiliensis infection; location matters over lineage.

Abstract

Abstract Our lab has previously shown that B1 B cells are important in the response to Nippostrongylus brasiliensus. We next wanted to examine the transcriptional changes between B1 and B2 B cells before and after N. brasiliensis infection. After examination of peritoneal cavity (PerC) B1 B cells and B2 B cells compared to mesenteric lymph node (MLN) B2 B cells by RNAseq we showed that there was more transcriptional similarity between PerC B cell populations than PerC B2 B cells and MLN B2 B cells. Due to this finding, we proceeded to determine the lineage of these B cells populations before and after helminth infection. To do this, one day postnatal, all B cells were depleted from CD45.1 IgMa haplotype mice using anti-IgMa antibody (DS.1). The following day the entire PerC lavage of an adult CD45.2 IgMb mouse was reconstituted, intraperitoneally. DS.1 was administered twice weekly until the mice were 6 weeks of age. After resting the mice to allow host bone marrow (BM) derived B cells to recover, the resulting mice had distinguishable B cell populations based on lineage. Interestingly, we found that regardless of whether the B cells were BM or fetal liver derived, both lineages were found in classically defined B1 B cell and B2 B cell population based on surfaces marker patterns by flow cytometry. In conclusion, this work suggests that anatomic location plays a larger role in terminal function than lineage, and that PerC B cell populations have a more ambiguous lineage than previously thought.