title: T-cell response to bacterial agents.
abstract: T-cell responses are crucial for the outcome of any infection. The type of effector T-cell reaction is determined by a complex interaction of antigen-presenting cells with naive T cells and involves genetic and environmental factors, including the type of antigen, cytokines, chemokines, co-stimulatory molecules, and signalling cascades. The decision for the immune response to go in a certain direction is based not on one signal alone, but rather on many different elements acting both synergistically and antagonistically, and through feedback loops leading to activation or inhibition of T cells. In the course of evolution different types of T cells have developed, such as T helper 1 (Th1) cells, which protect against intracellular bacteria; Th2 cells, which play a role against parasites; and Th17 cells, which face extracellular bacteria and fungi.
authors.affiliation: Department of Internal Medicine, University of Florence and Department of Biomedicine, Policlinico AOU Careggi Florence, Italy. delios@unifi.it
authors.forename: Mario Milco
authors.initials: MM
authors.lastname: D'Elios
authors.forename: Marisa
authors.initials: M
authors.lastname: Benagiano
authors.forename: Chiara
authors.initials: C
authors.lastname: Della Bella
authors.forename: Amedeo
authors.initials: A
authors.lastname: Amedei
mesh_terms: D000938:Antigen-Presenting Cells; D001424:Bacterial Infections / Q000276:immunology* / Q000517:prevention & control; D018925:Chemokines / Q000276:immunology; D006801:Humans; D007378:Interleukins / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology*; D058504:Th17 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D018925:Chemokines; D007378:Interleukins