Origins and functions of B-1 cells with notes on the role of CD5.
Annu Rev Immunol
; 20: 253-300, 2002.
Article
in En
| MEDLINE
| ID: mdl-11861604
ABSTRACT
Whether B-1a (CD5+) cells are a distinct lineage derived from committed fetal/neonatal precursors or arise from follicular B-2 cells in response to BCR ligation and other, unknown signals remains controversial. Recent evidence indicates that B-1a cells can derive from adult precursors expressing an appropriate specificity when the (self-) antigen is present. Antibody specificity determines whether a B cell expressing immunoglobulin transgenes has a B-2, B-1a or marginal zone (MZ) phenotype. MZ cells share many phenotypic characteristics of B-1 cells and, like them, appear to develop in response to T independent type 2 antigens. Because fetal-derived B cell progenitors fail to express terminal deoxynucleotidyl transferase (TdT) and for other reasons, they are likely to express a repertoire that allows selection into the B-1a population. As it is selected by self-antigen, the B-1 repertoire tends to be autoreactive. This potentially dangerous repertoire is also useful, as B-1 cells are essential for resistance to several pathogens and they play an important role in mucosal immunity. The CD5 molecule can function as a negative regulator of BCR signaling that may help prevent inappropriate activation of autoreactive B-1a cells.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
B-Lymphocyte Subsets
/
CD5 Antigens
Limits:
Animals
/
Humans
Language:
En
Journal:
Annu Rev Immunol
Year:
2002
Document type:
Article
Affiliation country:
United States