IgA response to Yersinia enterocolitica: role of Yop H

BLANCO H; DI GENARO S.

Potreros de los Funes, San Luis

Congreso; XXIV Reunión Científica Anual de la Sociedad de Biología de Cuyo, IV Reunión Científica de la Sociedad Argentina de Microscopía (SAMIC); 2006

Sociedad de Biología de Cuyo

The Yersinia outer protein (Yop) H is a thyrosine phosphatase that contributes to immune response evasion. Mutation in yopH of Y. enterocolitica has shown to result in attenuation. The objective was to study the role of Yop H on IgA response after oral infection with Yersinia in normal and immunodeficient mice. C57BL/6, TNFRp55-/-, IL-12p40-/- and IL-4-/- mice were infected with 5 x 108 wild type (WAP) or Yop H deficient (sycH-) Yersinia. Feces were obtained after infection (day 1-53) and bacterial number was determined. Yersinia-specific IgA in feces was measured by ELISA. The number of specific IgA-secreting cells in the spleen and mesenteric lymph nodes (MLN) was studied by ELISPOT assay. The sycH- strain was attenuated in wild-type and immunodeficient mice. On day 32, the number of bacteria was significantly higher in feces from WAP-infected C57BL/6 mice (p<0.0001). Yersinia-specific IgA response was detected in feces of wild-type and knockout mice after sycH- infection. IgA-secreting cell number was significantly increased in MLN of WAP infected mice (p<0.006).  However, significantly lower IgA level was detected in feces after WAP compared with sycH- infection (p<0.05). We concluded that Yersinia sycH- mutant induces IgA secretion. YopH could contribute to impair IgA transport in mucosa.