Berland R, Wortis HH. Normal B-1a cell development requires B cell-intrinsic NFATc1 activity.
Proc Natl Acad Sci U S A 2003;
100:13459-64. [PMID:
14595020 PMCID:
PMC263836 DOI:
10.1073/pnas.2233620100]
[Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
B-1a cells, an anatomically, phenotypically, and functionally distinct subset of B cells that produce the bulk of natural serum IgM and much of gut-associated IgA, are an important component of the early response to pathogens. Because the induced expression of CD5, a hallmark of B-1a cells, requires a nuclear factor of activated T cells (NFAT)-dependent enhancer, we examined the role of NFAT transcription factors in B-1a development. Here we show that the B-1a compartment is normal in mice lacking NFATc2 but essentially absent in mice lacking NFATc1. Loss of NFATc1 affects both peritoneal and splenic B-1a cells. Because there is a loss of B-1 cells defined by markers other than CD5, NFATc1 is not required simply for CD5 expression on B-1a cells. Using mixed-allotype chimeras and retroviral-mediated gene transduction we show that the requirement for NFATc1 is B cell-intrinsic. We also demonstrate that NFATc1 protein expression is elevated approximately 5-fold in B-1a cells compared with B-2 cells. This is the first definitive demonstration of a B cell-intrinsic function for an NFAT family transcription factor.
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