Some Considerations Relative to the Nature of Immunity in Trypanosoma lewisi Infections

Publisher Website
Google Scholar
Abstract
The demonstration that ablastin is an antibody directed against metabolic products, that this is the cause of agglutination as well as inhibition of reproduction of Trypanosoma lewisi, and that immune serum from recovered rats loses most of its potency when absorbed with metabolic products, indicates that ablastin is primarily responsible for immunity of rats to reinfection, and is also the agent responsible for at least the first number crisis, since agglutination is a precursor of phagocytic destruction of the parasites. Inhibition of reproduction is effected by a lower titer of ablastin than is agglutination; it is presumably due to neutralization by antibodies of excreted metabolic products, probably enzymes, which enable the parasites to avail themselves of some constituent or constituents of the environment that is required for growth and reproduction. The agglutination appears to be due to ablastln-ablastinogen combination in contact with the parasite bodies. Many experiments of earlier workers which seemed to indicate separate reproduction-inhibiting and trypanocidal antibodies seem to be adequately explained by quantitative relationships between ablastin and ablastinogen. The modifications in the course of T. lewisi infections resulting from deficiency of pantothenic acid and from administration of salicylates, demonstrated by Becker and his colleagues, seem explicable on the basis of interference with antibody (ablastin)-production, whereas the effect of benzene, demonstrated by Barnes, like the effect of splenectomy and blockade demonstrated by Taliaferro, seem explicable on the basis of partial interference with phagocytosis.