Yop effectors of Yersinia spp. and actin rearrangements

Abstract

Three species of the Yersinia genus are pathogenic for humans: Yersinia pestis, the agent of plague, which is usually transmitted by fleas and is often fatal, and Yersinia enterocolitica and Yersinia pseudotuberculosis, enteropathogens that typically cause self-limiting infections of the gastrointestinal tract. All three species share a marked tropism for lymphoid tissue. The enteropathogenic yersiniae encode invasin, a high-affinity ligand for β1 integrin extracellular matrix (ECM) receptors 1 Isberg R.R. Tran Van Nhieu G. Binding and internalization of microorganisms by integrin receptors. Trends Microbiol. 1994; 2: 10-14 Abstract Full Text PDF PubMed Scopus (164) Google Scholar . Binding of invasin to β1 integrins exposed on the luminal surface of M cells triggers efficient bacterial uptake and delivery into Peyer’s patches 2 Marra A. Isberg R.R. Invasin-dependent and invasin-independent pathways for translocation of Yersinia pseudotuberculosis across the Peyer’s patch intestinal epithelium. Infect. Immun. 1997; 65: 3412-3421 Crossref PubMed Google Scholar , 3 Siebers A. Finlay B.B. M cells and the pathogenesis of mucosal and systemic infections. Trends Microbiol. 1996; 4: 22-29 Abstract Full Text PDF PubMed Scopus (139) Google Scholar . After invading this niche, the yersiniae resist uptake by phagocytic cells and replicate extracellularly 3 Siebers A. Finlay B.B. M cells and the pathogenesis of mucosal and systemic infections. Trends Microbiol. 1996; 4: 22-29 Abstract Full Text PDF PubMed Scopus (139) Google Scholar . A plasmid-encoded type III protein secretion system endows these bacteria with the capacity to inhibit the anti-bacterial mechanisms of leukocytes 4 Cornelis G.R. et al. The virulence plasmid of Yersinia, an antihost genome. Microbiol. Mol. Biol. Rev. 1998; 62: 1315-1352 Crossref PubMed Google Scholar , 5 Hueck C.J. Type III protein secretion systems in bacterial pathogens of animals and plants. Microbiol. Mol. Biol. Rev. 1998; 62: 379-433 Crossref PubMed Google Scholar . Upon contact with the surface of a host cell, the type III system targets a set of six Yop effector proteins (YpkA, and YopH, M, T, J and E) into the cytoplasmic compartment of the eukaryote 4 Cornelis G.R. et al. The virulence plasmid of Yersinia, an antihost genome. Microbiol. Mol. Biol. Rev. 1998; 62: 1315-1352 Crossref PubMed Google Scholar , 6 Fällman M. et al. Yersinia proteins that target host cell signaling pathways. J. Clin. Invest. 1997; 99: 1153-1157 Crossref PubMed Scopus (37) Google Scholar . In cultured cells, targeted Yops have been shown to interfere with functions important for cell adhesion, phagocytosis, superoxide release, cytokine synthesis and survival 4 Cornelis G.R. et al. The virulence plasmid of Yersinia, an antihost genome. Microbiol. Mol. Biol. Rev. 1998; 62: 1315-1352 Crossref PubMed Google Scholar , 6 Fällman M. et al. Yersinia proteins that target host cell signaling pathways. J. Clin. Invest. 1997; 99: 1153-1157 Crossref PubMed Scopus (37) Google Scholar .