Cytophilic antibody in experimental Chagas' disease.

A method is described for estimating levels of cytophilic antibody against Trypanosoma cruzi in the sera of infected mice. 51Cr-labeled trypanosomes were incubated at 4 C in the presence of adherent, peritoneal cells which had been preincubated with immune or normal serum. It was found that immune, but not normal, serum mediated the enhanced binding of parasites in a manner dependent upon the amount of immune serum present during the preincubation period with peritoneal macrophages. Experiments were done comparing the development of anti-T. cruzi cytophilic antibody during the course of infection in two strains of mice which differ in susceptibility T. cruzi. It was found that neither C57BL/6 (resistant) nor C3H (susceptible) mice accumulated high levels cytophilic antibody, and no significant differences were noted in the level of cytophilic antibody in the sera of these two strains of infected mice. Attempts to stimulate higher levels of anti-T. cruzi cytophilic antibody by immunization with several preparations of culture-forms of the parasite were only minimally effective.