GSE174394
Lineage tracking reveals origins and relative affinities of antibodies produced by two subsets of memory B cells
Memory B cells comprise a heterogenous group of cells that differ in origin, and phenotype. During the early phases of the immune response, activated B cells can differentiate into IgM expressing memory cells, short-lived plasma cells or seed germinal centers (GCs). The memory compartment is subsequently enriched by B cells that have been through several rounds of division and selection in the GC. Here we report on the use of an unbiased lineage tracking approach to explore the origins and properties of memory B cell subsets in mice with an intact immune system. We find that activated B cells continue to differentiate into memory B cells throughout the immune response. When defined on the basis of their origins, the memory B cells originating from activated B cells or GCs differ in isotype and overall gene expression, somatic hypermutation, and in their affinity for antigen. Overall design: Memory B cell subsets in mice with an intact immune system were examined. Cells were sorted directly into a solution of 1% 2-ß-mercaptoethanol (Sigma) in TCL Buffer (Qiagen, 1031576) and RNA was isolated using RNAClean XP Beads (Beckman Coulter, A63987). Near full-length mRNA was reverse transcribed as previously described (Islam et al., 2014) (Trombetta et al., 2014). Multiplexed libraries were prepared for sequencing using a Nextera XT DNA Library Preparation Kit (Illumina). Libraries were sequenced on an Illumina NovaSeq 6000 at the Rockefeller University Genomics Core.