Transitional B cells: step by step towards immune competence

James B Chung1, Michael Silverman, John G Monroe

  • 1Division of Rheumatology, Department of Medicine, University of Pennsylvania, Philadelphia 19104, USA.

Trends in Immunology
|June 18, 2003
PubMed

Transitional B cells mark the crucial link between bone-marrow (BM) immature and peripheral mature B cells. Examination reveals unexpected heterogeneity, consisting of contiguous subsets with phenotypic and functional differences. Data point to the late transitional B-cell stage as a crucial juncture at which developing B cells gain access to splenic follicles, become responsive to T-cell help and lose sensitivity to negative selection, characterizing the immature B-cell response to B-cell antigen receptor (BCR) signaling in vitro and in vivo. The biological and molecular processes directing maturation through this stage are becoming clearer through biochemical studies and murine models deficient in various components of the BCR signaling pathway.

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