title: T cells require tumor necrosis factor-alpha to provide protective immunity in mice infected with Histoplasma capsulatum.
abstract: We examined whether neutralization of tumor necrosis factor (TNF)-alpha after intranasal exposure of mice to Histoplasma capsulatum was necessary for control of primary or secondary infection. All mice given monoclonal antibody to TNF-alpha on the day of infection or on day 3 after infection died. When antibody was administered on day 5 after infection, 60% of mice with primary infection died, whereas none with secondary infection did. Antibody treatment on day 7 after infection produced a transiently higher fungal burden. Because optimal clearance required TNF-alpha after the onset of infection, we hypothesized that it may regulate T cell function. Lung CD3+ cells were the dominant population of TNF-alpha-producing cells (approximately 40%-70%). Neutralization of this cytokine decreased the number of memory T cells but not the number of activated, proliferating, or interferon-gamma-producing cells. T cells from infected, TNF-alpha-neutralized mice failed to protect T cell-deficient mice. The absence of TNF-alpha induces a defect in T cell-mediated protection.
authors.affiliation: Division of Infectious Diseases, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0560, USA. george.deepe@uc.edu
authors.forename: George S
authors.initials: GS
authors.lastname: Deepe
authors.forename: Reta S
authors.initials: RS
authors.lastname: Gibbons
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D004195:Disease Models, Animal; D005434:Flow Cytometry; D006658:Histoplasma / Q000276:immunology*; D006660:Histoplasmosis / Q000276:immunology*; D008168:Lung / Q000382:microbiology; D016131:Lymphocyte Subsets / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D013154:Spleen / Q000382:microbiology; D016019:Survival Analysis; D013601:T-Lymphocytes / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D014409:Tumor Necrosis Factor-alpha