Figure 1

Nasal or i.m. immunization with Hcβtre-Ad2F induces enhanced serum IgG and mucosal IgA anti-Hcβtre Ab responses. BALB/c mice were immunized by the (A,B) i.n. or (C,D) i.m. route with equimolar concentrations of Hcβtre (25 μg) or Hcβtre-Ad2F (50 μg), either alone or with combination with cholera toxin (CT), as a mucosal adjuvant, on days 0, 7, and 14. Sera and fecal extracts were collected at weekly intervals beginning on day 14 post-primary immunization. Fecal IgA (A,C) and serum IgG (B,D) Ab titers against Hcβtre were determined by ELISA. The addition of vaccine-targeting molecule, Ad2F, in the absence and the presence of CT, improved mucosal Ab responses when compared to mice immunized with Hcβtre only. Without adjuvant, both groups induced weak IgG Abs responses. Data are expressed as mean ± SEM of three different experiments (n = 15 mice). *, p ≤ 0.001; **, p ≤ 0.05 represent the significant differences in IgA and IgG anti-Hcβtre levels between mice immunized with Hcβtre-Ad2F and Hcβtre with or without CT.