Most peripheral B cells in mice are ligand selected.

TLDR

The selection of B cells in mice lacking class switching and somatic hypermutation differs from T cell‑dependent memory B‑cell selection. The authors analyzed the VH gene repertoire of pre‑B cells and various B‑cell subsets in conventional mice by amplifying cDNA and genomic libraries and evaluating the data against a curated list of 67 J558 VH genes that represent about two‑thirds of the murine IgHb haplotype. They found that pre‑B cells use a broad range of J558 VH genes, whereas mature peripheral B cells express only small overlapping sets of germline VH genes, indicating that recruitment into the long‑lived peripheral pool is driven by positive selection through internal or external antigens.

Abstract

Using amplified cDNA and genomic libraries, we have analyzed the VH gene repertoire of pre-B cells and various B cell subsets of conventional mice at the level of VH genes belonging to the J558 VH gene family. The sequence data were evaluated on the basis of a newly established list of 67 J558 VH genes that comprise approximately two-thirds of the J558 VH genes of the murine IgHb haplotype. The results of the analysis demonstrate that VH gene utilization in pre-B cells, although biased to some extent by B cell autonomous VH gene selection, scatters over the whole range of J558 VH genes present in the germline. In contrast, in mature, peripheral B cells comprising long-lived mu + delta high B cells as well as Ly-1 B cells, small overlapping sets of germline VH genes are dominantly expressed. The data indicate that the recruitment of newly generated B cells into the long-lived peripheral B cell pool is mediated through positive selection by internal and/or external antigens. Because of the absence of immunoglobulin class switching and somatic hypermutation, this process is different from the selection of memory B cells in T cell-dependent immune responses.