Identification and characterization of a full-length cDNA encoding paramyosin of Trichinella spiralis.

Abstract A full-length cDNA encoding Trichinella spiralis paramyosin ( Ts -Pmy) was cloned by immunoscreening a cDNA library of the adult T. spiralis worm . Ts -Pmy cDNA consists of 2655 bp that encode 885 amino acids. The recombinant protein (r Ts -Pmy) was expressed and purified by Ni-affinity chromatography. Western blot analysis showed that r Ts -Pmy could be recognized by sera from T. spiralis -infected humans, swine, rabbits, and mice. Immunolocalization demonstrated that Ts -Pmy was abundant on the surface of T. spiralis larvae. BALB/c mice vaccinated with r Ts -Pmy demonstrated 36.2% reduction in muscle larvae burden following T. spiralis larvae challenge. Vaccination of the mice with r Ts -Pmy resulted in a high level of specific anti- Ts -Pmy IgG antibodies and generated a Th1/Th2 mixed type of immune response, with Th2 predominant. These studies showed that r Ts -Pmy induced protective immunity in mice and could be considered as a potential vaccine candidate for trichinellosis.