Distinctive developmental origins and specificities of murine CD5+ B cells.
CD5+ B cells constitute a small fraction of cells in the spleen of adult mice that exhibit numerous features serving to distinguish them from the bulk of IgD++CD5- "conventional" B cells. In this review we focus on two major questions relating to this population: 1) the relationship of CD5+ B cells to other B cells; and 2) the distinctive enrichment of particular autoreactive specificities in this subset. The nature of their origins is clarified by a thorough analysis of intermediate stages of early B-cell development in both fetal and adult tissues. The reactivity to bromelain-treated mouse red blood cells serves as a prototype system for the investigation of biased specificities in CD5+ B cells. These lines of investigation lead us to propose that CD5+ B cells in the adult are the remnant of a distinct fetal B-cell differentiation pathway wherein selection of cells from this fetal/neonatal population into the adult long-lived pool results in the over-expression of certain germline-encoded autoreactivities.
Hardy
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I.C.R., Fox Chase Cancer Center, Philadelphia, PA 19111.
Carmack
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CE
Li
Y S
YS
Hayakawa
K
K
D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000276:immunology*; D001402:B-Lymphocytes / Q000502:physiology*; D001483:Base Sequence; D018956:CD5 Antigens; D002454:Cell Differentiation; D000939:Epitopes / Q000276:immunology*; D015322:Gene Rearrangement, B-Lymphocyte / Q000235:genetics / Q000276:immunology; D005803:Genes, Immunoglobulin / Q000276:immunology; D007072:Immunoglobulin D / Q000276:immunology; D008969:Molecular Sequence Data
D015703:Antigens, CD; D018956:CD5 Antigens; D000939:Epitopes; D007072:Immunoglobulin D