Comparative immunological studies on somatic antigens and secretion-excretion products of blood stream and culture forms of Trypanosoma lewisi. I. Protective immunity and the agglutinin response.

Abstract

Trypanosoma lewisi is a parasitic protozoan hemoflagellate of the rat. Morphological, physiological, and antigenic alterations of the parasites are observed during the course of the infection. The blood stream forms (BSF) of T. lewisi show 2 morphologically distinguishable types as reported by Taliaferro [1]. The reproducing forms of the parasites, so-called dividing forms, exhibit variability in their size and shape. The parasites cease reproduction by the eight to ninth day, become slender and uniform in size, and are known as nondividing or adult forms. The change from dividing forms to adult forms occurs in response to a host factor, ablastin, the reproduction-inhib