title: Activated Langerhans cells release tumor necrosis factor.
abstract: Langerhans cells act as antigen-presenting cells in immune reactions in the skin. What other roles they may play in inflammation is less well defined. We have tested whether these cells can produce TNF-alpha, an important mediator of inflammation. Resting Langerhans cells produce less than 0.1 U TNF-alpha/ml. Langerhans cells stimulated with phorbol myristate acetate (PMA) and lipopolysaccharide (LPS) release 4-5 U TNF-alpha/ml. Specificity of the released TNF-alpha in an L929 cytotoxicity assay was confirmed by using neutralizing anti-TNF-alpha monoclonal antibodies, and the identity of TNF-alpha was further confirmed by Northern blot hybridization with an TNF-alpha oligomer DNA probe. Activated Langerhans cells may contribute to inflammation in the skin by releasing TNF-alpha, which is known to effect fibroblast growth, endothelial cell activation, and lymphocyte function.
authors.affiliation: Psoriasis Research Institute, Stanford Medical Center, Palo Alto, California.
authors.forename: J W
authors.initials: JW
authors.lastname: Larrick
authors.forename: V
authors.initials: V
authors.lastname: Morhenn
authors.forename: Y L
authors.initials: YL
authors.lastname: Chiang
authors.forename: T
authors.initials: T
authors.lastname: Shi
mesh_terms: D006801:Humans; D015151:Immunoblotting; D066298:In Vitro Techniques; D007801:Langerhans Cells / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha