Construction and protective effect of targeting antimicrobial peptide against Toxoplasma / 中国血吸虫病防治杂志

ABSTRACT

Objective To construct, express and purify human scFv antibody (S1) against the recombinant SAG1 of Toxoplasma fused to magainin, and observe its protective effect against Toxoplasma in infected mice. Methods The S1 scFv antibody gene amplified from phagmid S1/pIT-2 fused to magainin was cloned into procaryotic expression vector pET-32c. The recombinant plasmid S1M/pET-32c proved by DNA sequencing was transformed into E.coli BL21, and induced for fusion expression of S1M with IPTG. The expressed S1M was purified with Ni 2+ chelating HiTrap HP column and detected with SDS-PAGE. The effect of reduction of infection of Toxoplasma was observed through in vivo and in vitro experiments in mice. Results The fused gene of S1 and magainin was successfully cloned into procaryotic expression vector pET-32c proved by DNA sequencing. The recombinant S1M protein about 43 kDa was expressed in E.coli as inclusion body, and prepared with Ni 2+ column purification. Tachyzoite of Toxoplasma preincubated with S1M showed decreased infectivity in mice, the result of in vivo experiments showed that mice treated with S1M hadlonger survival time than the mice untreated. Conclusion The purified targeting antimicrobial peptide S1M could reduce the infectivity of tachyzoites of Toxoplasma in a certain extent and has a potential value for biological therapy of toxoplasmosis; otherwise, the constructed targeting antimic robial peptide S1M also provides a new model for biological therapy of toxoplasmosis.