Positive selection of IgG+ over IgM+ B cells in the germinal center reaction.
Immunity
; 54(5): 988-1001.e5, 2021 05 11.
Article
em En
| MEDLINE
| ID: mdl-33857421
ABSTRACT
Positive selection of high-affinity B cells within germinal centers (GCs) drives affinity maturation of antibody responses. Here, we examined the mechanism underlying the parallel transition from immunoglobulin M (IgM) to IgG. Early GCs contained mostly unswitched IgM+ B cells; IgG+ B cells subsequently increased in frequency, dominating GC responses 14-21 days after antigen challenge. Somatic hypermutation and generation of high-affinity clones occurred with equal efficiency among IgM+ and IgG+ GC B cells, and inactivation of Ig class-switch recombination did not prevent depletion of IgM+ GC B cells. Instead, high-affinity IgG+ GC B cells outcompeted high-affinity IgM+ GC B cells via a selective advantage associated with IgG antigen receptor structure but independent of the extended cytoplasmic tail. Thus, two parallel forms of GC B-cell-positive selection, based on antigen receptor variable and constant regions, respectively, operate in tandem to ensure high-affinity IgG antibodies predominate in mature serum antibody responses.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Imunoglobulina G
/
Imunoglobulina M
/
Linfócitos B
/
Centro Germinativo
Limite:
Animals
Idioma:
En
Revista:
Immunity
Assunto da revista:
ALERGIA E IMUNOLOGIA
Ano de publicação:
2021
Tipo de documento:
Article