title: Antigen presentation by rat brain and retinal endothelial cells.
abstract: Brain and retinal endothelial cells (EC) form the blood-brain and vascular blood-retinal barriers, respectively, and are believed to play a role in mediating T cell responses in the central nervous system. In this study, Lewis rat retinal and brain EC grown in vitro were capable of expressing MHC class II I-A but not I-E molecules following treatment with interferon-gamma. In the presence of their antigen, CD4+ antigen-specific T cells were able to mediate lysis of retinal EC monolayers to a similar extent as brain EC. T cell proliferation was poorly supported by confluent retinal or brain EC monolayers, but subconfluent EC monolayers supported proliferation in a MHC class II (I-A)-restricted manner (P < 0.001). Exposure of T cells to confluent retinal EC monolayers resulted in them becoming less responsive to subsequent antigen presentation by thymocytes. Conversely, pre-exposure with subconfluent EC had no such effect. These results suggest that a non-proliferating EC monolayer is able to downregulate T cell responsiveness which may have important implications during lymphocyte traffic across the blood-tissue barriers of the central nervous system.
authors.affiliation: Department of Clinical Science, Institute of Ophthalmology, London, UK.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: V L
authors.initials: VL
authors.lastname: Calder
authors.forename: S L
authors.initials: SL
authors.lastname: Lightman
authors.forename: J
authors.initials: J
authors.lastname: Greenwood
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D000941:Antigens / Q000276:immunology; D019393:Arrestin; D001812:Blood-Brain Barrier / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002450:Cell Communication; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D004730:Endothelium, Vascular / Q000276:immunology*; D005136:Eye Proteins / Q000276:immunology; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D008213:Lymphocyte Activation; D051381:Rats; D011917:Rats, Inbred Lew; D012160:Retina / Q000276:immunology*
chemical_list: D000941:Antigens; D019393:Arrestin; D005136:Eye Proteins; D000949:Histocompatibility Antigens Class II