ABSTRACT
Objective To study the prokaryotic expression and immune protection of triosephosphate isomerase(TPI)of Toxoplasma gondii in mice. Methods Total RNA was extracted from toxoplasma tachyzoites,and TPI fragment was amplified by PCR and cloned into the prokaryotic expression vector pET-28a(+). The target protein was induced with IPTG and purified by Ni-NTA affinity chromatography. The mice were immunized 4 times by emulsified TPI with adjuvant,and the last time was the strengthen immunization. At the same time,an adjuvant group and a normal group were set as controls. The blood samples were got from the tail vein of the mice,and the serum antibody titres were detected. All the mice were challenged with 400 toxo-plasma tachyzoites to observe the survival time. Results The TPI gene was amplified from T. gondii cDNA by PCR. The recom-binant vector TPI/pET-28a(+)was usefully constructed,and the TPI protein was expressed and purified. The serum antibody ti-tre could be more than 100 thousand. After infected with toxoplasma tachyzoites,the survival time of the mice in the experimen-tal group was longer than that of the mice in the control groups. Conclusion The TPI protein of T. gondii could trigger the im-munoprotection against T. gondii challenge in the mice.