Single-cell analysis of bone marrow B220+ cells from 56R and LAPTM5 knockout (LAPTM5KO) 56R mice

We used single-cell transcriptomics and BCR sequencing to analyze B cell development in 56R and LAPTM5KO 56R mice. We found increased proportions of immature B and mature B cells in LAPTM5KO 56R mice compared to 56R mice. QuSAGE analysis revealed that immature B cells from LAPTM5KO 56R mice were enriched in PI3K-Akt, mTOR, Ras and MAPK signaling pathways that contribute to cell survival. Moreover, mature B cells from LAPTM5KO 56R mice were enriched for activated autoimmune disease and transplant rejection pathways compared with those from 56R mice, suggesting that LAPTM5KO 56R mice might be more susceptible to autoimmunity. Single-cell BCR sequencing showed that LAPTM5 deficiency resulted in less reduction in LC diversity in mature B compared to immature B cells. Overall design: Examination of bone marrow B lineage cells in 3 pairs of 56R and LAPTM5 deficient 56R mice