IQGAP1 restrains T-cell cosignaling mediated by OX40.
FASEB J
; 34(1): 540-554, 2020 01.
Article
em En
| MEDLINE
| ID: mdl-31914585
ABSTRACT
A costimulatory signal from the tumor necrosis factor receptor (TNFR) family molecule OX40 (CD134), which is induced on activated T cells, is important for T-cell immunity. Aberrant OX40 cosignaling has been implicated in autoimmune and inflammatory disorders. However, the molecular mechanism by which the OX40 cosignaling regulates the T-cell response remains obscure. We found that OX40 associated with a scaffold protein, IQ motif-containing GTPase-activating protein 1 (IQGAP1) after ligation by its ligand OX40L. Naïve CD4+ T cells from Iqgap1-/- mice displayed enhanced proliferation and cytokine secretion upon receiving OX40 cosignaling. A C-terminal IQGAP1 region was responsible for its association with OX40, and TNFR-associated factor 2 (TRAF2) bridged these two proteins. The enhanced cytokine response in Iqgap1-/- T cells was restored by the expression of the C-terminal IQGAP1. Thus, the IQGAP1 binding limits the OX40 cosignaling. Disease severity of experimental autoimmune encephalomyelitis (EAE) was significantly exacerbated in Iqgap1-/- mice as compared to wild-type mice. Additionally, recipient mice with Iqgap1-/- donor CD4+ T cells exhibited significantly higher EAE scores than those with their wild-type counterparts, and OX40 blockade led to a significant reduction in the EAE severity. Thus, our study defines an important component of the OX40 cosignaling that restricts inflammation driven by antigen-activated T cells.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ativação Linfocitária
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Linfócitos T CD4-Positivos
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Proteínas Ativadoras de ras GTPase
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Encefalomielite Autoimune Experimental
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Receptores OX40
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Memória Imunológica
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Inflamação
Limite:
Animals
Idioma:
En
Revista:
FASEB J
Assunto da revista:
BIOLOGIA
/
FISIOLOGIA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Japão