Molecular cloning and characterization of heat shock protein 70 from Trichinella spiralis

Abstract A cDNA encoding heat shock protein 70 of Trichinella spiralis ( Ts -Hsp70) was identified by immunoscreening the adult T. spiralis cDNA library with rabbit antisera against T. spiralis adult extracts. The open reading frame of Ts -Hsp70 cDNA encoded a 623-amino acid peptide with a predicted molecular weight of 68.7 kDa, which shares a high degree of sequence conservation with HSP70s from other parasites. Recombinant Ts -Hsp70 was expressed in Escherichia coli and purified with nickel column chromatography. Western blot analysis showed that recombinant Ts -Hsp70 could be recognized not only by trichinellosis patient sera, but also by T. spiralis -infected sera from rabbits, swine, and mice. Mice vaccinated with recombinant Ts -Hsp70 formulated with Freund's adjuvant exhibited strong humoral immune responses indicated by high titer of IgG antibody and significant muscle larval reduction (37%) after being challenged with T. spiralis larvae. The present results indicate that Ts -Hsp70 is a possible candidate vaccine against T. spiralis infection.