Effect of Coiled-Coil Peptides on the function of TTSS of EHEC O157:H7 and the Citrobacter rodentium on the C. rodentium. Pathogenicity in Mice.

LARZÁBAL MARIANO; ZOTTA ELSA; IBARRA CRISTINA; RAVINOVITZ BETTINA; VILTE DANIEL; MERCADO ELSA; CATALDI ANGEL

Amsterdam

Simposio; VTEC2012: 8th International Symposium on Shiga Toxin (Verocytotoxin)-producing Escherichia coli infections.; 2012

Gram-negative bacteria such as Salmonella, Yersinia, EnterohemorrhagicEscherichia coli (EHEC) and Enteropathogenic Escherichia coli(EPEC) possess a type III secretion system (TTSS) that is used todeliver virulence proteins directly into the host cell. Recent evidencesuggested that Coil A and Coil B, two synthetic peptides correspondingto coiled-coil domains of the translcator protein EspA, wereeffective in inhibiting the action of TTSS from enteropathogenic E.coli (EPEC).Results: In the current study, the action of these coiled-coil peptideson the TTSS of EHEC O157:H7 and C. rodentium was examined.CoilA and CoilB showed to be effective in reducing the red bloodcell (RBC) lysis mediated by EHEC O157:H7 and the in vitro secretionof translocator proteins EspB and EspD by EHEC O157:H7 andEspD by C. rodentium. Treatment of mice with CoilA and CoilBpeptides prevented colon damage when the animals were inoculatedwith C. rodentium. Colon samples of the non-treated group showedareas with loss of superficial epithelium, damaged cells and endoluminalmononuclear inflammatory infiltrate, consistent with histologicallesion induced by C. rodentium, whereas mice treated with thesynthetic peptides kept normal the surface epithelium showing asimilar structure as the uninfected control group.Conclusions: These encouraging results prompted us to test coiledcoilpeptides as treatment or vaccines in other models of bacterialinfections.