PMID: 9164953Jun 1, 1997Paper

Protection of mice against Trypanosoma cruzi by immunization with paraflagellar rod proteins requires T cell, but not B cell, function

The Journal of Immunology : Official Journal of the American Association of Immunologists
M J MillerJerry E Manning

Abstract

Previous studies have shown that immunization of mice with the paraflagellar rod proteins (PAR) of Trypanosoma cruzi induces an immune response capable of protecting mice against an otherwise lethal challenge with this parasite. Herein, we define immunologic responses that do or do not play a critical role in PAR-mediated protection. Firstly, PAR-immunized Ab-deficient (muMT) strain mice survived an otherwise lethal T. cruzi challenge, indicating that a B cell response is not required for PAR-induced immunity. However, beta2m -/- mice, which are severely deficient in MHC class I and TCR alphabeta+ CD8+ CD4- T cells, did not survive challenge infection following PAR immunization, indicating that MHC class I/CD8+ T cell function is necessary for protection induced by PAR immunization. Surprisingly, PAR-immunized mice depleted of CD4+ T cells survived a T. cruzi challenge for >84 days postinfection while maintaining a parasitemia that is generally thought to be lethal (i.e., >10(6) trypomastigotes/ml), thus associating CD4+ T cell function with the process of parasite clearance. Consistent with this association, CD4+ T cells from PAR-immunized mice released INF-gamma and stimulated T. cruzi-infected macrophages to release nitric o...Continue Reading

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