A nematode allergen elicits protection against challenge infection under specific conditions

We describe tropomyosin of the filarial nematode Acanthocheilonema viteae as an allergen and study its protective potential in the natural rodent host Meriones unguiculatus (jird). Jirds immunized with recombinant E. coli-expressed A. viteae tropomyosin emusified in alum were not protected, while immunization with recombinant A. viteae tropomyosin or with protein purified from worms together with the adjuvant STP led to reduction of adult worm burdens by 30%. Vaccination with cDNA induced protection of about 30%, while application of cDNA together with aluminium phosphate increased the protection to >40%. Our data suggest that vaccination with tropomyosin under Th1 conditions, which are untypical for nematode infections, induces protection via an antibody independent effector mechanism.