Transcriptional profile of B cells isolated from neonatal and adult hearts

We have identified four distinct B cell subgroups within the naïve murine heart, whose relative expression changed markedly throughout development, including CD19+CD11b+CD5+, CD19+CD11b+CD5-, CD19+CD11b-CD21+CD23+, and CD19+CD11b-CD21-CD23- B cells. In order to gain further insight into the identity of the various myocardial B cells subsets, we performed single cell RNA sequencing (scRNAseq) of neonatal (2 weeks) and adult (8 weeks) myocardial B cells. We combined 10X single cell gene expression analysis with immunostaining using TotalSeq antibodies against CD11b, CD23, and CD21. We performed transcriptional profiling of cardiac B cells isolated from 6 neonatal (2 weeks old) and 6 adult (8 weeks old) wild-type mice. We used the Chromium Single Cell 3′ v3 Chromium instrument (from 10x Genomics) to perform single cell transcriptional profiling analyses.