Immunological Properties of a Trypanosomal Lipopolysaccharide and its Effects on the Infection with Trypanosoma (Schizotrypanum) cruzi

Abstract

A lipopolysaccharide, TCLP, was obtained from culture form of T.(S) cruzi by extraction with phenol-water at 68° C. Unlike the lipopolysac-charides obtained from Gramnegative bacteria, TCLP lacked adjuvant action on antibody formation, did not react with complement and was incapable of sensitizing rabbits for or eliciting the Shwartzman phenomenon, Mice given TCLP showed an initial short period of increased reticuloen-dothelial clearance of colloidal carbon, followed by a 2-day period of significantly depressed clearance.

TCLP had an adverse effect on mice infected with virulent forms of T. (S.) cruzi. Peak parasitemias were significantly increased over those of control animals (given only the parasite). Early mortality also ensued. These effects were found to be independent of the sequence of administration of TCLP and the parasite.

Prior immunization with TCLP did not prevent either the disease or death in mice challenged with virulent T.(S.) cruzi