title: CD14 expression by activated parenchymal microglia/macrophages and infiltrating monocytes following human traumatic brain injury.
abstract: The immune response in the central nervous system (CNS) is under tight control of regulatory mechanisms, resulting in the establishment of immune privilege. CNS injury induces an acute inflammatory reaction, composed mainly of invading leukocytes and activated microglial cells/macrophages. The generation of this robust immune response requires binding of receptors such as CD14, a pattern recognition receptor of the immune system. CD14, a surface molecule of monocytic cells, is up-regulated after monocyte stimulation and is involved in cellular activation. To examine CD14 expression in human brain lesions we investigated sections of brains obtained at autopsy from 25 cases following closed traumatic brain injury (TBI) and 5 control brains by immunohistochemistry. Detection of CD14 in controls demonstrated constitutive expression by perivascular cells, but not in parenchymal microglial cells, equivalent to known expression pattern of ED2 in rats. Following TBI, numbers of CD14(+) cells in perivascular spaces and in the brain parenchyma increased in parallel within 1-2 days, both at the lesion and in adjacent perilesional areas. The number of CD14(+) cells in perivascular spaces and in the brain parenchyma reached maximum levels within 4-8 days and remained elevated until weeks after trauma. In contrast to activated parenchymal microglia/macrophages, resting parenchymal microglial cells lacked CD14. Thus, early CD14 expression constitutes an essential part of the acute inflammatory CNS response following trauma.
authors.affiliation: Institute of Brain Research, University of Tübingen, Medical School, Calwerstr. 3, 72076, Germany. rudi.beschorner@med.uni-tuebingen.de
authors.forename: Rudi
authors.initials: R
authors.lastname: Beschorner
authors.forename: Thai D
authors.initials: TD
authors.lastname: Nguyen
authors.forename: Fatma
authors.initials: F
authors.lastname: Gözalan
authors.forename: Ingo
authors.initials: I
authors.lastname: Pedal
authors.forename: Rainer
authors.initials: R
authors.lastname: Mattern
authors.forename: Hermann J
authors.initials: HJ
authors.lastname: Schluesener
authors.forename: Richard
authors.initials: R
authors.lastname: Meyermann
authors.forename: Jan M
authors.initials: JM
authors.lastname: Schwab
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000276:immunology / Q000378:metabolism; D000943:Antigens, Differentiation / Q000276:immunology / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000276:immunology / Q000378:metabolism; D001808:Blood Vessels / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D001921:Brain / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D001930:Brain Injuries / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D002135:Calcium-Binding Proteins / Q000276:immunology / Q000378:metabolism; D040501:Calgranulin A; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism / Q000648:ultrastructure; D002634:Chemotaxis, Leukocyte / Q000276:immunology*; D005110:Extracellular Space / Q000276:immunology / Q000378:metabolism; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D018950:Lipopolysaccharide Receptors / Q000276:immunology* / Q000378:metabolism; D008264:Macrophages / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D008297:Male; D017628:Microglia / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D008875:Middle Aged; D009000:Monocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D015214:Antigens, Differentiation, Myelomonocytic; D002135:Calcium-Binding Proteins; D040501:Calgranulin A; D000949:Histocompatibility Antigens Class II; D018950:Lipopolysaccharide Receptors; C067980:CD68 antigen, human; D000097382:CD68 Molecule