Protective efficacy of H antigen from Histoplasma capsulatum in a murine model of pulmonary histoplasmosis.
We previously reported that immunization with H antigen from Histoplasma capsulatum did not protect mice against an intravenous challenge with yeasts. Here, we investigated the utility of H antigen to protect mice in a model of pulmonary histoplasmosis. Mice immunized with H antigen and challenged intranasally 4 weeks postvaccination were protected against sublethal and lethal challenges with H. capsulatum yeasts. If the challenge was performed 3 months after vaccination, there was a reduction in fungal burden following sublethal challenge and a modest delay in mortality in mice given a lethal inoculum. Vaccination was associated with production of gamma interferon, granulocyte-macrophage colony-stimulating factor, interleukin-4, and interleukin-10 by splenocytes. Vaccination with H antigen was not accompanied by a major expansion of CD4(+) or CD8(+) cells in spleens of mice. These results demonstrate that H antigen may be useful as a protective immunogen against pulmonary exposure to H. capsulatum.
Deepe
G S
GS
Division of Infectious Diseases, Department of Medicine, University of Cincinnati College of Medicine, OH 45267-0560, USA.
Gibbons
R
R
D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis; D006658:Histoplasma / Q000276:immunology*; D006660:Histoplasmosis / Q000517:prevention & control*; D007114:Immunization; D016130:Immunophenotyping; D018664:Interleukin-12 / Q000494:pharmacology; D008172:Lung Diseases, Fungal / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D013997:Time Factors
D000942:Antigens, Bacterial; D016207:Cytokines; C022863:H antigen; D018664:Interleukin-12