A Study of Cytoplasmic Inclusions in Trypanosoma lewisi and their Relationship to the Formation of Antibody

Abstract

Developmental forms of Trypanosoma lewisi continue to increase in number when the "crisis" (normally occurring at the 10th day) is inhibited; the inclusions which they contain also increase in number, density and retractile power. Suspensions of killed developmental forms containing multiple inclusions have greater protective power against a challenge infection than have similar suspensions of adult forms which contain a single inclusion. It is suggested that the multiple inclusions contain an antigenic factor which stimulates the production of a trypanocidal antibody and reacts with it to produce the crisis, but the single inclusions of the adult forms which survive the crisis have different antigenic properties.