AQP8 transports NOX2-generated H2O2 across the plasma membrane to promote signaling in B cells.
J Leukoc Biol
; 100(5): 1071-1079, 2016 11.
Article
em En
| MEDLINE
| ID: mdl-27256569
ABSTRACT
H2O2 acts as a second messenger in key signaling circuits, transiently modulating tyrosine phosphatases and kinases. We investigated its origin, membrane transport, and functional role during B cell activation and differentiation. Our data identified NADPH-oxidase 2 as the main source of H2O2 and aquaporin 8 as a transport facilitator across the plasma membrane. On aquaporin 8 silencing, inducible B lymphoma cells responded poorly to TLR and BCR stimulation. Their differentiation was severely impaired, as demonstrated by retarded onset of IgM polymerization, low amounts of IgM secretion, and prolonged BCR expression on the cell surface. A silencing-resistant aquaporin 8 rescued responsiveness, confirming that the import of H2O2 across the membrane is essential for B cell activation. The addition of exogenous catalase to primary B splenocytes severely impaired the tyrosine phosphorylation induced by BCR cross-linking, as did the absence of NOX2 in a murine model of chronic granulomatous disease. Importantly, re-expression of gp91phox through gene therapy restored the specific B cell signaling deficiency in NOX2-/- cells. Thus, efficient induction of B cell activation and differentiation requires intact H2O2 fluxes across the plasma membrane for signal amplification.
Palavras-chave
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Glicoproteínas de Membrana
/
Linfócitos B
/
NADPH Oxidases
/
Aquaporinas
/
Peróxido de Hidrogênio
Limite:
Animals
Idioma:
En
Revista:
J Leukoc Biol
Ano de publicação:
2016
Tipo de documento:
Article