title: T cells mediate cross-protective immunity between spotted fever group rickettsiae and typhus group rickettsiae.
abstract: Rickettsioses are severe infections caused by obligately intracellular bacteria that preferentially infect the endothelium lining the vasculature. The causative agents, rickettsiae, have been divided according to biological, genetic, and antigenic parameters into 2 main groups: spotted fever and typhus. They have not been thought to stimulate cross-reactive protective immune responses; however, in this study, we show that, in relevant animal models that mimic human rickettsial infections, there is reciprocal immunological cross-protection between spotted fever group and typhus group rickettsiae. Furthermore, we present evidence that T cells are responsible for this cross-immunity and that cross-stimulation of T cells also occurs in humans.
authors.affiliation: Department of Pathology, University of Texas Medical Branch, Galveston, Texas 77555-0609, USA.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Valbuena
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Jordan
authors.forename: David H
authors.initials: DH
authors.lastname: Walker
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D003429:Cross Reactions; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D020114:Rickettsia conorii / Q000276:immunology*; D012286:Rickettsia typhi / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D007371:Interferon-gamma