Immunization against Trypanosoma lewisi in rats by injections of metabolic products
Thillet, Carlos Juan, Jr
Doctor of Philosophy
In the present work we have attempted to determine the general nature and source of the specific antigen or antigens stimulating the formation of the antibody (ablastin) which inhibits the reproduction of T. lewisi , and to study the relations of the antibody thus stimulated to the course of infection with T. lewisi in rats, and to the various phenomena associated with immunity and resistance of rats to this parasite. We have also analyzed and discussed results and interpretations of other workers who have postulated the involvement of several functionally distinct antibodies, and we have suggested that, on the basis of our findings, ablastin may account for all or nearly all of the phenomena observed, and may be the only important antibody involved in the defense mechanism of rats against this parasite. Data obtained in the course of our experiments support the hypothesis first proposed by Chandler (1935) that in the case of Trypanosoma lewisi, as in the case of Nippostrongylus muris and probably a great many other parasites, true functional immunity is dependent upon antibodies directed against excreted metabolic products of the parasites, most probably enzymes, as a consequence of which the nutrition or metabolism of the parasites is interfered with in such a way as to retard growth, development and reproduction.