BCR heavy and light chain repertoire sequencing of pertitoneal cavity B-1a cells from wild-type and Igll1 knockout mice

We report that B-1a cells develop in a surrogate light chain independent context. As a consequence, the precursor B-1a cell population avoids a pre-BCR positive selection stage. To confirm that the B-1a cells generated in this manner repersent a bonafide B-1a cell compartment, we did NGS on BCR rearrangements to assess the repertoire diversity. We find that as a whoile, B-1a cell repertoire that develop in Igll1 kncokout mice are similar compared to wild-type. This supports our findings that B-1a cells develop properly in the absence of surrogate light chain. Peritoneal cavity B-1a cells were sorted from 6-8 week old mice, DNA was extracted and rearranged heavy chains were amplified by PCR. These PCR products were then process to form DNA libraries that were compatible with Illumina NGS.