RT Journal Article SR Electronic(1) A1 Nobe, Rika A1 Nougayrède, Jean-Philippe A1 Taieb, Frédéric A1 Bardiau, Marjorie A1 Cassart, Dominique A1 Navarro-Garcia, Fernando A1 Mainil, Jacques A1 Hayashi, Tetsuya A1 Oswald, EricYR 2009 T1 Enterohaemorrhagic Escherichia coli serogroup O111 inhibits NF-κB-dependent innate responses in a manner independent of a type III secreted OspG orthologue JF Microbiology, VO 155 IS 10 SP 3214 OP 3225 DO https://doi.org/10.1099/mic.0.030759-0 PB Microbiology Society, SN 1465-2080, AB Enterohaemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC) inject a repertoire of effector proteins into host cells via a type III secretion system (T3SS) encoded by the locus of enterocyte effacement (LEE). OspG is an effector protein initially identified in Shigella that was shown to inhibit the host innate immune response. In this study, we found ospG homologues in EHEC (mainly of serogroup O111) and in Yersinia enterocolitica. The T3SS encoded by the LEE was able to inject these different OspG homologues into host cells. Infection of HeLa cells with EHEC O111 inhibited the NF-κB-dependent innate immune response via a T3SS-dependent mechanism. However, an EHEC O111 ospG mutant was still able to inhibit NF-κB p65 transfer to the nucleus in infected cells stimulated by tumour necrosis factor α (TNF-α). In addition, no difference in the inflammatory response was observed between wild-type EHEC O111 and the isogenic ospG mutant in the rabbit ligated intestinal loop model. These results suggest that OspG is not the sole effector protein involved in the inactivation of the host innate immune system during EHEC O111 infection., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.030759-0