title: Analysis of the cells involved in the lymphoproliferative response to Coxiella burnetii antigens.
abstract: Vaccination with an inactivated, whole cell, Q fever vaccine (Q-vax) induces lasting antibody conversion and a positive delayed-type hypersensitivity (DTH) skin reaction in about 60% of recipients but a long-lasting positive lymphoproliferative or mitogenic response to C. burnetii antigens with peripheral blood mononuclear cells (PBMC) in 85-95% of subjects. Analysis of the lymphoproliferative response to C. burnetii antigens has now been made by fractionation-reconstitution experiments with PBMC from vaccines, from past infections, and from healthy controls. The major contributor to the response in immune subjects proved to be the T lymphocyte. T cells were stimulated by both the phase I and phase II antigens of two prototype strains of C. burnetii and responses were greatly amplified by addition of IL-2. Similar T lymphocyte stimulation profiles were obtained with the 'Priscilla' strain of C. burnetii which represents a different biotype of Coxiella isolated from Q fever endocarditis; Q-vax is therefore likely to protect against endocarditis strains. Fractionation-reconstitution experiments with T and B cells from vaccines and subjects infected in the past, using various antigenic or haptenic fractions from C. burnetii indicate that protein, non-lipopolysaccharide components of the organism are responsible for the mitogenic response of immune T cells. However, the role of the lipopolysaccharide in the protective immunogen has still to be defined.
authors.affiliation: Department of Pathology, University of Adelaide, Australia.
authors.forename: A A
authors.initials: AA
authors.lastname: Izzo
authors.forename: B P
authors.initials: BP
authors.lastname: Marmion
authors.forename: T
authors.initials: T
authors.lastname: Hackstadt
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D003381:Coxiella / Q000276:immunology*; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000276:immunology*; D009000:Monocytes / Q000276:immunology; D011778:Q Fever / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control; D013601:T-Lymphocytes / Q000276:immunology*; D014612:Vaccines
chemical_list: D000942:Antigens, Bacterial; D007376:Interleukin-2; D014612:Vaccines