| First Author | Daly CA | Year | 2020 |
| Journal | J Immunol | Volume | 205 |
| Issue | 9 | Pages | 2362-2374 |
| PubMed ID | 32978280 | Mgi Jnum | J:303626 |
| Mgi Id | MGI:6502478 | Doi | 10.4049/jimmunol.1901453 |
| Citation | Daly CA, et al. (2020) B Cell Subsets Differentially Contribute to the T Cell-Independent Memory Pool. J Immunol 205(9):2362-2374 |
| abstractText | The roles distinct B cell subsets play in clonal expansion, isotype switching, and memory B cell differentiation in response to T cell-independent type 2 Ags (TI-2 Ags) has been understudied. Using sorted B cells from VHB1-8 knock-in mice, we evaluated B-1b, marginal zone, and follicular B cell responses to the TI-2 Ag, NP-Ficoll. All subsets extensively divided in response to NP-Ficoll. Nonetheless, B-1b cells exhibited significantly increased IgG switching and differentiation into Ab-secreting cells (ASC)-a finding that coincided with increased AgR signaling capacity and Blimp1 expression by B-1b cells. All subsets formed memory cells and expressed markers previously identified for T cell-dependent memory B cells, including CD80, PDL2, and CD73, although B-1b cells generated the greatest number of memory cells with higher frequencies of IgG- and CD80-expressing cells. Despite memory formation, secondary immunization 4 wk after primary immunization did not increase NP-specific IgG. However, boosting occurred in B-1b cell-recipient mice when IgG levels declined. CD80(+) memory B-1b cells divided, class switched, and differentiated into ASC in response to Ag in vivo, but this was inhibited in the presence of NP-specific IgG. Furthermore, CD80 blockade significantly increased memory B-1b cell division and differentiation to ASC upon Ag restimulation. Collectively, these findings demonstrate B-1b, marginal zone B, and follicular B subsets significantly contribute to the TI-2 Ag-specific memory B cell pool. In particular, we show B-1b cells generate a functional CD80-regulated memory population that can be stimulated to divide and differentiate into ASC upon Ag re-encounter when Ag-specific IgG levels decline. |
