Studies on Immune Responses to Parasite Antigens in Mice

Abstract

Normal mice of several strains reject the nematode worm N. brasiliensis from the intestine within 14 days (and most often within 10 days) of injection of high numbers of infective 3rd stage larvae (L3). Previously-infected mice are markedly resistant to a 2nd infection. Hypothymic, nu/nu (nude) mice continue to harbor worms long after intact mice have rejected the worm burden. An inoculum of T [thymus-derived] cells at the time of, or several days after L3 injection, leads to worm elimination within 14 days in nu/nu mice. No evidence is available to indicate whether T cells with specificity for parasite antigens are required in a reconstitutive inoculum in nu/nu mice. Pretreatment of normal mice with cyclophosphamide, at doses reported to lead to temporary B [bone marrow-derived] cell hypofunction, does not result in delayed rejection of worms; but the participation of B cell products (antibodies) cannot be discounted on the basis of this result.