Efficacy of cell-free antigens in evaluating cell immunity and inducing protection in a murine model of histoplasmosis

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Author(s):	Sá-Nunes, Anderson ; Medeiros, Alexandra I. ; Nicolete, Roberto ; Frantz, Fabiani Gai ^[4] ; Panunto-Castelo, Ademilson ; Silva, Célio L. ; Faccioli, Lúcia Helena Total Authors: 7
Document type:	Journal article
Source:	Microbes and Infection; v. 7, n. 4, p. 584-592, Apr. 2005.
Field of knowledge:	Biological Sciences - Immunology
Abstract
Histoplasma capsulatum is a dimorphic pathogenic fungus that causes a wide spectrum of disease when mycelial fragments are inhaled. Resistance to H. capsulatum is dependent on cellular immunity mediated by T cells and macrophages. Here we standardized the production of extracts containing cell-free antigens (CFAgs) and observed their efficacy in evaluating cellular immunity during murine histoplasmosis. CFAgs induced a more potent delayed-type hypersensitivity (DTH) response in H. capsulatum-infected mice than did histoplasmin-a classical antigen. This DTH response to CFAgs is able to determine the immune status of infected mice and to predict their death. Moreover, CFAgs stimulated spleen cells from immune mice to produce higher amounts of gamma interferon (IFN-gamma) in vitro. Finally, immunization with CFAgs protected against a lethal inoculum of H. capsulatum. These results demonstrate that CFAgs may be useful for the evaluation of cellular immune response and as a potential source for the development of a vaccine against histoplasmosis. (AU)