NLRP3 inflammasome activation downstream of cytoplasmic LPS recognition by both caspase-4 and caspase-5.
Eur J Immunol
; 45(10): 2918-26, 2015 Oct.
Article
em En
| MEDLINE
| ID: mdl-26173988
ABSTRACT
Humans encode two inflammatory caspases that detect cytoplasmic LPS, caspase-4 and caspase-5. When activated, these trigger pyroptotic cell death and caspase-1-dependent IL-1ß production; however the mechanism underlying this process is not yet confirmed. We now show that a specific NLRP3 inhibitor, MCC950, prevents caspase-4/5-dependent IL-1ß production elicited by transfected LPS. Given that both caspase-4 and caspase-5 can detect cytoplasmic LPS, it is possible that these proteins exhibit some degree of redundancy. Therefore, we generated human monocytic cell lines in which caspase-4 and caspase-5 were genetically deleted either individually or together. We found that the deletion of caspase-4 suppressed cell death and IL-1ß production following transfection of LPS into the cytoplasm, or in response to infection with Salmonella typhimurium. Although deletion of caspase-5 did not confer protection against transfected LPS, cell death and IL-1ß production were reduced after infection with Salmonella. Furthermore, double deletion of caspase-4 and caspase-5 had a synergistic effect in the context of Salmonella infection. Our results identify the NLRP3 inflammasome as the specific platform for IL-1ß maturation, downstream of cytoplasmic LPS detection by caspase-4/5. We also show that both caspase-4 and caspase-5 are functionally important for appropriate responses to intracellular Gram-negative bacteria.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
2_ODS3
/
3_ND
Base de dados:
MEDLINE
Assunto principal:
Infecções por Salmonella
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Salmonella typhimurium
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Monócitos
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Proteínas de Transporte
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Lipopolissacarídeos
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Caspases
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Caspases Iniciadoras
Limite:
Humans
Idioma:
En
Revista:
Eur J Immunol
Ano de publicação:
2015
Tipo de documento:
Article