IMMUNOLOGICAL CONSEQUENCES OF INTESTINAL HELMINTH INFECTIONS - HUMORAL RESPONSES TO OVALBUMIN

Humoral responses to ovalbumin (OA) administered i.p. with Al(OH)3 were depressed in C57BL mice immunized 5-13 days after infection with Nematospiroides dubius, but not Nippostrongylus brasiliensis or Trichuris muris. These 2 parasites induced elevated IgM responses, possibly as a result of systemic contact with parasite larvae or debris since i.v. administered N. dubius also increased IgM titers to OA. Depression of anti-OA IgG titers by N. dubius was also observed in infected BALB/c and CBA mice given OA-Al(OH)3 (i.p.), but not in C57BL mice given OA-Al(OH)3 (s.c.), OA-FCA (i.p or s.c.), or OA-Bordetella pertussis (i.p.). These findings suggest that local effects of N. dubius within the peritoneum reduce the adjuvanticity of Al(OH)3, resulting in depressed responses to OA-Al(OH)3.