title: Activation of T Lymphocytes in Response to Persistent Bacterial Infection: Induction of CD11b and of Toll-Like Receptors on T Cells.
abstract: T cell activation is invariably associated with virus infections, but activation of T cells is also noted, for example, in patients with persistent bacterial infections with intracellular pathogens or localised bacterial biofilms. The latter is characterised by a destructive inflammatory process. Massive infiltration of leukocytes, predominantly of polymorphonuclear neutrophils (PMNs) and of T lymphocytes, is seen. While PMN influx into sites of bacterial infection is in line with their role as "first-line defence" a role of T cells in bacterial infection has not yet been delineated. We now found evidence for activation and expansion of peripheral blood T cells and an upregulation of Toll-like receptors 1, 2, and 4 on small portions of T cells. T cells recovered from the infected site were terminally differentiated and produced interferon gamma, a cytokine known to enhance functions of phagocytic cells, leading to the conclusion that infiltrated T cells support the local immuner defence.
authors.affiliation: Institut für Immunologie, Universität Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Dimitra
authors.initials: D
authors.lastname: Kotsougiani
authors.forename: Marco
authors.initials: M
authors.lastname: Pioch
authors.forename: Birgit
authors.initials: B
authors.lastname: Prior
authors.forename: Volkmar
authors.initials: V
authors.lastname: Heppert
authors.forename: G Maria
authors.initials: GM
authors.lastname: Hänsch
authors.forename: Christof
authors.initials: C
authors.lastname: Wagner