Antibody response to stage-specific Trichinella spiralis surface antigens in strong and weak responder mouse strains.

The antibody response to antigens on the cuticular surface of Trichinella spiralis was compared in two strains of mice, NIH mice, which control the parasite relatively strongly, and C3H, which reject this nematode more slowly. The evolution of the antibody response to the nematode surface was monitored by the appearance of antibodies that mediate the adherence of eosinophils to the worm and the appearance of antibodies that recognize molecules on the surface that can be labeled with 125I. Antibody responses were measured using three life cycle stages; muscle stage larvae, immature and mature intestinal stages, and newborn larvae. We found that NIH mice responded immunologically to the four molecules found in extracts of surface-labeled T. spiralis adult worms, but that C3H mice did not produce antibodies to one of these molecules until much later in the infection. NIH mice produced antibodies against both infective larvae antigens by day 4 after infection, whereas C3H recognized only one before day 30. Variations in antibody response also occurred against antigens on the surface of newborn larvae: antibody to one of these antigens was not present in C3H immune sera until day 30. Sera from the two strains likewise differed in their ability to mediate eosinophil adherence to each parasite stage, and in some of the life cycle stages, these differences corresponded to the recognition of specific antigens found on the parasites' surface. The links between recognition of defined parasitic antigens and the fate of the parasite in genetically different strains of mice are discussed.