Prokaryotic expression of the antigen gene Ts43 of Trichinella spiralis and identification of its recombinant protein

To express the antigen gene Ts43 of Trichinella spiralis and identify the antigenicity of the recombinant protein,the antigen gene Ts43 of T.spiralis was cloned into the prokaryotic expression vector pET30a(+) and the recombinant pET30a(+)-Ts43 was constructed.The recombinant plasmid was transformed into an E.coli BL21 and induced by IPTG.The antigenicity of the recombinant protein was identified by SDS-PAGE and Western blotting.The results showed the relative molecular weight of the expressed fusion protein was about 41 000 and the expression level peaked at 4 h post-incubation.The portion of the fusion protein accounted for 14.7% of all the protein by thin-layer gel optical scanning.On Western blotting analysis,the recombinant protein was recognized by sera from mice infected with T.spiralis(T1),with T.nativa(T2) and T.nelsoni(T7) as well as sera of patients with trichinellosis,but not cross-reacted with sera from mice infected with B.hominis,C.parum,and sera from normal mice and persons.However,the recombinant protein was cross-reacted with sera from patients with echinococcosis,cysticercosis,schistosomiasis,paragonimiasis and clonorchiasis.The recombinant protein of T.spiralis Ts43 antigen gene has the antigenicity,but it shows the cross-reaction with sera from patients with certain other parasitic diseases.