AIM To incorporate p12 in a plasmid under the control of the CMV promotor and test for the ability of theconstruct to produce specific immune responses in DNA-immunized mice.METHODS A His-tag fusion of the protein p12, was expressed in the prokaryotic expression vector (pQE)and the recombinant protein purified using nickel-chelate chromatography. His-tagged p12 was sub-clonedinto the pBK-CMV vector for expression in eukaryotic systems. Groups of six female balb/c mice werevaccinated with either 50μg im of the DNA pBK-CMV-p12 or pBK-CMV vector alone at week 0, andboosted at 2 and 4 weeks. ELISPOT assays (detection of p12 T-cell dependant IF-γ release) on mouse spleniccells were used to measure cell mediated immune responses and anti-mouse IgG ELISAs to detect antibodyresponse.RESULTS Significant CMI and humoral immune responses to recombinant p12 were detected in micevaccinated with pBK-CMV-p12 vector compared to mice vaccinated with pBK-CMV vector alone. The miceremained well throughout the development of immunity to p12.CONCLUSION A DNA vaccine coding for a specific MAP protein will stimulate humoral and cell mediatedimmune responses in mice.