Within germinal centers, isotype switching of immunoglobulin genes occurs after the onset of somatic mutation.
Immunity
; 4(3): 241-50, 1996 Mar.
Article
em En
| MEDLINE
| ID: mdl-8624814
ABSTRACT
Human tonsillar B cells were separated into naive IgD+CD38-CD23- (Bm1) and IgD+CD38-CD23 (Bm2), germinal center IgD-CD38+CD23- centroblasts (Bm3) and IgD-CD38+CD77- centrocytes (Bm4) and memory IgD-CD38- (Bm5) subsets. Previous IgVH sequence analysis concluded that the triggering of somatic mutations occurs during the transition from Bm2 subset into the Bm3 subset. To determine the initiation of isotype switching, sterile transcript expression was analyzed by amplification, cloning, and sequencing. A selective sterile I gamma, I alpha, and I epsilon expression was observed at centrocyte (Bm4) stage, suggesting that isotype switch is triggered within germinal centers, after somatic mutation is initiated with centroblasts (Bm3). Finally, the high level of 5'S gamma-S mu 3' DNA switching circles observed in germinal center B cells indicates that within human tonsils, germinal center is a major location for isotype switching.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Genes de Imunoglobulinas
/
Rearranjo Gênico do Linfócito B
/
Antígenos de Histocompatibilidade Classe II
/
Switching de Imunoglobulina
/
Centro Germinativo
/
Mutação
Limite:
Humans
Idioma:
En
Revista:
Immunity
Assunto da revista:
ALERGIA E IMUNOLOGIA
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
França