DNA vaccine coding a p23 protein of Cryptosporidium parvum fused with Fc portion of immunogloblin G induces higher level of interferon-γ expression in mice

To develop DNA vaccines against cryptosporidiosis, a plasmid coding an immunodominant protein of Cryptosporidium parvum sporozoite, p23 (pCX-p23) and another plasmid coding a fusion protein containing whole the p23 and the Fc portion of mouse immunogloblin G1 (pCX-p23Fc). Vaccination of BALB/c mice with the plasmid, pCX-p23 and pCX-p23Fc induced the production of antibodies against p23. Although both of splenocytes of mice immunized with the plasmids pCX-p23 and pCX-p23Fc expressed interleukin-4 and interferon-8, after the in vitro stimulation by p23 antigen, the interferon-8 expression level of pCX-p23Fc immunized mice was much higher than that of pCX-p23 immunized mice. These results suggest a possibility of the plasmid pCX-p23Fc as a DNA vaccine candidate against cryptosporidiosis.