Immunization with Nematospiroides dubius adult worms plus pertussigen has different consequences in mice of various genotypes.

In the Nematospiroides dubius/mouse model of intestinal nematodiasis, young C57BL/6 male mice are highly susceptible in that they remain chronically infected after repeated oral administrations of infective third-stage larvae (L3). It was shown previously that a parenteral injection of small numbers of living adult worms, or their aqueous extracts, was highly effective at sensitizing these mice for accelerated rejection of adult worms but only when the mice were additionally injected with pertussigen from Bordetella pertussis. 'Host protective antigens' appear to be soluble proteins. This method of vaccination is largely ineffective in male mice of strains CBA/H and C3H/He and can actually be counterproductive in BALB/c mice. Thus, adult worms injected subcutaneously into male BALB/c mice will sensitize them for accelerated rejection and this effect is neutralized by simultaneous injection of such mice with pertussigen. The data highlight the known complexity of host-parasite relationships in intestinal parasitism and suggest that several different defects underlie the genetically based inability of some mice to reject N. dubius worms from the intestines following exposure to N. dubius antigens.