Scarcity of autoreactive human blood IgA+ memory B cells.
Eur J Immunol
; 46(10): 2340-2351, 2016 10.
Article
em En
| MEDLINE
| ID: mdl-27469325
ABSTRACT
Class-switched memory B cells are key components of the "reactive" humoral immunity, which ensures a fast and massive secretion of high-affinity antigen-specific antibodies upon antigenic challenge. In humans, IgA class-switched (IgA+ ) memory B cells and IgA antibodies are abundant in the blood. Although circulating IgA+ memory B cells and their corresponding secreted immunoglobulins likely possess major protective and/or regulatory immune roles, little is known about their specificity and function. Here, we show that IgA+ and IgG+ memory B-cell antibodies cloned from the same healthy humans share common immunoglobulin gene features. IgA and IgG memory antibodies have comparable lack of reactivity to vaccines, common mucosa-tropic viruses and commensal bacteria. However, the IgA+ memory B-cell compartment contains fewer polyreactive clones and importantly, only rare self-reactive clones compared to IgG+ memory B cells. Self-reactivity of IgAs is acquired following B-cell affinity maturation but not antibody class switching. Together, our data suggest the existence of different regulatory mechanisms for removing autoreactive clones from the IgG+ and IgA+ memory B-cell repertoires, and/or different maturation pathways potentially reflecting the distinct nature and localization of the cognate antigens recognized by individual B-cell populations.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Autoanticorpos
/
Imunoglobulina A
/
Linfócitos B
/
Memória Imunológica
/
Diversidade de Anticorpos
Limite:
Humans
Idioma:
En
Revista:
Eur J Immunol
Ano de publicação:
2016
Tipo de documento:
Article