title: Variation in interferon-gamma responses to Coxiella burnetii antigens with lymphocytes from vaccinated or naturally infected subjects.
abstract: Previous work in our laboratory has shown that lymphocytes from persons vaccinated with a formalin-inactivated Phase I Q fever vaccine (Q-Vax CSL Ltd) show a mitogenic response to Coxiella burnetii antigens. The mitogenic response is the sum of that from various subsets of CD4+, T helper cells, CD8+ T cells and probably B cells. It does not distinguish between T helper cell responses leading to formation of interferon-gamma (IFN-gamma)--a cytokine responsible for clearing intracellular infection with C. burnetii organisms--and responses of other T cell subsets which may produce disease-enhancing cytokines. The present study analyses (i) the capacity of Q-Vax to induce T cell sensitization which leads to IFN-gamma responses on antigen stimulation, and (ii) the immunomodulatory, (down-regulatory) effects of the Phase I lipopolysaccharide (LPS) of the organism, which interacts with monocyte/macrophages to limit IL-2 production and production of IFN-gamma by sensitized T lymphocytes.
authors.affiliation: Department of Pathology, University of Adelaide, South Australia.
authors.forename: A A
authors.initials: AA
authors.lastname: Izzo
authors.forename: B P
authors.initials: BP
authors.lastname: Marmion
mesh_terms: D000942:Antigens, Bacterial / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology; D002478:Cells, Cultured; D016997:Coxiella burnetii / Q000276:immunology*; D015536:Down-Regulation; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D006801:Humans; D007124:Immunoenzyme Techniques; D007371:Interferon-gamma / Q000096:biosynthesis*; D007376:Interleukin-2 / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008264:Macrophages / Q000276:immunology; D009000:Monocytes / Q000276:immunology; D011778:Q Fever / Q000276:immunology* / Q000517:prevention & control; D013601:T-Lymphocytes / Q000276:immunology*; D014611:Vaccination
chemical_list: D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D007376:Interleukin-2; D008070:Lipopolysaccharides; D007371:Interferon-gamma