Cowpox virus encodes a protein that binds B7.1 and B7.2 and subverts T cell costimulation.
Proc Natl Acad Sci U S A
; 116(42): 21113-21119, 2019 10 15.
Article
em En
| MEDLINE
| ID: mdl-31575740
ABSTRACT
Costimulation is required for optimal T cell activation, yet it is unclear whether poxviruses dedicatedly subvert costimulation during infection. Here, we report that the secreted M2 protein encoded by cowpox virus (CPXV) specifically interacts with human and murine B7.1 (CD80) and B7.2 (CD86). We also show that M2 competes with CD28 and CTLA4 for binding to cell surface B7 ligands, with stronger efficacy against CD28. Functionally, recombinant M2 and culture supernatants from wild-type (WT) but not M2-deficient (∆M2) CPXV-infected cells can potently suppress B7 ligand-mediated T cell proliferation and interleukin-2 (IL-2) production. Furthermore, we observed increased antiviral CD4 and CD8 T cell responses in C57BL/6 mice challenged by ∆M2 CPXV compared with WT virus. These differences in immune responses to ∆M2 and WT CPXV were not observed in CD28-deficient mice. Taken together, our findings define a mechanism of viral sabotage of T cell activation that highlights the role of CD28 costimulation in host defense against poxvirus infections.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Virais
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Ativação Linfocitária
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Linfócitos T CD4-Positivos
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Vírus da Varíola Bovina
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Antígeno B7-1
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Linfócitos T CD8-Positivos
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Antígeno B7-2
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article