Immunogenicity of p55 Gene Fragment from Pneumocystis carinii / 中国寄生虫学与寄生虫病杂志

ABSTRACT

Objective To evaluate immunogenicity of the recombinant protein GST-p55/570 of Pneumocystis carinii.Methods The fusion protein GST-p55/570 was expressed from the prokaryotic expression plasmid pGEX-570,and purified by using glutathione-agarose.The expressed product was analyzed by SDS-PAGE.Thirty-three mice were randomly divided into three groups,immunized with GST-p55/570,GST and PBS,respectively.Each group was immunized for four times at 2 week intervals.At the 7th day after final immunization,spleen was removed to obtain single cell suspension.Proliferation ability of lymphocytes was determined by MTT.Serum samples were collected at pre-immunizaton and two weeks after each immunization.Antibody level in sera of mice was determined by ELISA.The immune response to the recombinant GST-p55/570 recognized by sera of immunized mice was examined by Western blotting.Results The expressed fusion protein GST-p55/570 showed a Mr 47 000.Compared with GST group(1.134 5?0.073 5) or PBS group(1.124 8?0.041 6),a higher stimulation index(2.063 0?0.160 2) was revealed in GST-p55/570-immunized mice(P