Mitogen-Activated Protein Kinase-Dependent Interleukin-1α Intracrine Signaling Is Modulated by YopP during Yersinia enterocoliticaInfection

Autor: Bose, Rumu, Thinwa, Josephine, Chaparro, Paola, Zhong, Youmin, Bose, Santanu, Zhong, Guangming, Dube, Peter H.
Zdroj: Infection and Immunity; November 2011, Vol. 80 Issue: 1 p289-297, 9p
Abstrakt: ABSTRACTYersinia enterocoliticais a food-borne pathogen that preferentially infects the Peyer's patches and mesenteric lymph nodes, causing an acute inflammatory reaction. Even though Y. enterocoliticainduces a robust inflammatory response during infection, the bacterium has evolved a number of virulence factors to limit the extent of this response. We previously demonstrated that interleukin-1α (IL-1α) was critical for the induction of gut inflammation characteristic of Y. enterocoliticainfection. More recently, the known actions of IL-1α are becoming more complex because IL-1α can function both as a proinflammatory cytokine and as a nuclear factor. In this study, we tested the ability of Y. enterocoliticato modulate intracellular IL-1α-dependent IL-8 production in epithelial cells. Nuclear translocation of pre-IL-1α protein and IL-1α-dependent secretion of IL-8 into the culture supernatant were increased during infection with a strain lacking the 70-kDa virulence plasmid compared to the case during infection with the wild type, suggesting that Yersiniaouter proteins (Yops) might be involved in modulating intracellular IL-1α signaling. Infection of HeLa cells with a strain lacking the yopPgene resulted in increased nuclear translocation of pre-IL-1α and IL-1α-dependent secretion of IL-8 similar to what is observed with bacteria lacking the virulence plasmid. YopP is a protein acetylase that inhibits mitogen-activated protein kinase (MAP kinase)- and NF-κB-dependent signal transduction pathways. Nuclear translocation of pre-IL-1α and IL-1α-dependent secretion of IL-8 in response to Yersinia enterocoliticainfection were dependent on extracellular signal-regulated kinase (ERK) and p38 MAP kinase signaling but independent of NF-κB. These data suggest that Y. enterocoliticainhibits intracellular pre-IL-1α signaling and subsequent proinflammatory responses through inhibition of MAP kinase pathways.
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