4). EPEC samples (E2348/69) pre-treated for 3 h with dilutions of serum or fecal extracts obtained from mice immunized with BCG-bfpA, BCG-intimin, Smeg-bfpA or Smeg-intimin, were added to HEp-2 monolayers cultivated on coverslips. As a negative control, EPEC (E2348/69) samples were similarly pre-treated with dilutions of serum

or feces collected prior to the immunizations. After incubation for click here 3 h at 37 °C, the coverslips were stained and examined by light microscopy. Untreated EPEC (E2348/69) typically displays a localized pattern of adhesion, generating tight microcolonies of bacteria on the epithelial cell surface. As shown in Fig. 5A–C, adherence of EPEC (E2348/69) cells pre-treated with dilutions of immune serum or fecal extracts was blocked by over 90%. In contrast, in EPEC (E2348/69) cells pre-treated with dilutions of serum or feces collected before immunization, adherence was blocked by less than 5%. Attenuated M. bovis BCG vaccine strains have been intensively investigated as a vehicle for delivering heterologous antigens and allowing the induction of both humoral (mucosal and systemic) and cell-mediated immune responses [21]. In this study, we used recombinant BCG that expressed BfpA or intimin ABT-199 price as vaccines against EPEC. As an alternative,

M. smegmatis was also used to present the BfpA and intimin antigens to the host. It is interesting to note that the recombinant strains of both species were able to induce systemic and mucosal BfpA and intimin-specific antibody responses with adherence-neutralizing activity following oral administration to mice. This evidence demonstrates that the different rBCG-EPEC or Smeg-EPEC vaccine strains are potential live vectors for the generation

Dipeptidyl peptidase of strategies to prevent EPEC. Three important qualities for a recombinant vaccine were positively evaluated in our study. First, a live attenuated vaccine was constructed with the ability to express two important proteins, BfpA and intimin, involved in the pathogenesis of EPEC. Second, the expression of the recombinant proteins induced specific and long lasting immune response in immunized mice, characterized by serum and mucosal IgG and IgA antibodies. The third important property of our recombinants is that the induced antibodies were able to prevent, in in vitro EPEC adherence to HEp-2 cells. IgA production was probably enhanced by the adjuvant effects of mesoporous silica SBA-15 [20]. SBA-15 is a nontoxic positive modulator of the mucosal immune response even in low immune responsive mice and is a natural candidate to be included as an adjuvant in an anti-EPEC vaccine. The anti-EPEC antibodies specifically recognize recombinant and native BfpA and intimin proteins free in solution and naturally fixed on the bacterial cell surfaces (Fig. 1A and B). The significant production of TNF-α and IFN-γ identifies BfpA and intimin as inducers of cellular immunity [22] and [23].