title: Importance of T lymphocytes in brain injury, immunodeficiency, and recovery after cerebral ischemia.
abstract: Following an ischemic stroke, T lymphocytes become activated, infiltrate the brain, and appear to release cytokines and reactive oxygen species to contribute to early inflammation and brain injury. However, some subsets of T lymphocytes may be beneficial even in the early stages after a stroke, and recent evidence suggests that T lymphocytes can also contribute to the repair and regeneration of the brain at later stages. In the hours to days after stroke, T-lymphocyte numbers are then reduced in the blood and in secondary lymphoid organs as part of a 'stroke-induced immunodeficiency syndrome,' which is mediated by hyperactivity of the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis, resulting in increased risk of infectious complications. Whether or not poststroke T-lymphocyte activation occurs via an antigen-independent process, as opposed to a classical antigen-dependent process, is still controversial. Although considerable recent progress has been made, a better understanding of the roles of the different T-lymphocyte subpopulations and their temporal profile of damage versus repair will help to clarify whether T-lymphocyte targeting may be a viable poststroke therapy for clinical use.
authors.affiliation: Vascular Biology and Immunopharmacology Group, Department of Pharmacology, Monash University, Clayton, Victoria, Australia.
authors.forename: Vanessa H
authors.initials: VH
authors.lastname: Brait
authors.forename: Thiruma V
authors.initials: TV
authors.lastname: Arumugam
authors.forename: Grant R
authors.initials: GR
authors.lastname: Drummond
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Sobey
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000473:pathology; D001921:Brain / Q000276:immunology* / Q000473:pathology; D002545:Brain Ischemia / Q000276:immunology* / Q000473:pathology / Q000628:therapy; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000276:immunology / Q000473:pathology; D007153:Immunologic Deficiency Syndromes / Q000276:immunology* / Q000473:pathology / Q000628:therapy; D007239:Infections / Q000276:immunology / Q000473:pathology; D007249:Inflammation / Q000276:immunology / Q000473:pathology / Q000628:therapy; D008213:Lymphocyte Activation; D010913:Pituitary-Adrenal System / Q000276:immunology / Q000473:pathology; D020521:Stroke / Q000276:immunology* / Q000473:pathology / Q000628:therapy; D013601:T-Lymphocytes / Q000276:immunology* / Q000473:pathology