IFN-g and IL-17 responses influence protective immune response to Yersinia enterocolitica.

DAVE MABEL NOEMÍ; AUTENRIETH INGO B; DI GENARO MARÍA SILVIA

Lima

Congreso; Inmunoperú 2012; 2012

Asociación Latinoamaericana de Inmunología (ALAI)

Yersinia enterocolitica (Ye) is an enteropathogenic bacterium that possess virulence factors known as Yops (Yersinia outer proteins). YopH is a powerful phosphotyrosine phosphatase that inhibits phagocytosis and T cell activation. The purpose was to address whether YopH influences Th1 and Th17 balance after oral Ye infection. C57BL/6 wild-type (WT) or IL-12/23p40-/- mice were orally infected with 1-5 ?~ 108 Ye O:8 WA-314 or with a YopH deletion mutant (?¢yopH) strain. After 5 or 7 days, the mice were killed and Peyer?fs patches (PP), mesenteric lymph nodes (MLN) and spleen (S) were aseptically removed to determine the numbers of colony forming units (CFU)/organ and cytokines by ELISA. We found lower CFU number in PP, MLN and S after Ye ?¢yopH infection in WT mice (p<0.001). In MLN, Ye WA-314 induced higher IL-12/23p40 and IFN-g levels at days 5 and 7, respectively (p<0.05 compared with ?¢yopH strain). In contrast, ?¢yopH strain induced higher IL-17 production in MLN at day 7 that was in line with higher levels of IL-6 and TGF-b at day 5 (p<0.05). The number of CFU increased in IL-12/23p40-/- compared with WT mice after Ye ?¢yopH infection, and this increment associated with decreased levels of IL-17 (p<0.05). We concluded that Ye ?¢yopH strain changes Th1 to Th17 cytokine profile suggesting a crutial rol of IL-17 and IL-12/23p40 in the attenuation of this mutante strain.