title: Oligoclonal activation of CD4+ T lymphocytes in posterior uveitis.
abstract: Several lines of evidence support an important role for activated T lymphocytes in the perpetuation of autoimmune intraocular inflammatory disease (posterior uveitis). In this study peripheral blood lymphocytes (PBL) were examined by three-colour flow cytometry to assess the distribution of IL-2 receptors (IL-2R) among CD4+ and CD8+ T cell subsets in patients with active posterior uveitis and control subjects. Patients with uveitis (n = 70) showed a significant increase in PBL expressing the alpha-chain (Tac) of the IL-2R compared with controls (n = 28) (34.2% versus 29.6%) (P < 0.05). This increased Tac expression was present on both the CD4+ subset (25.7% versus 20.9%) (P < 0.05) and the CD8+ subset (2.5% versus 1.8%) (P < 0.05) of lymphocytes. We also examined whether the activated CD4+ PBL from uveitis patients (n = 30) showed a dominant pattern of T cell receptor (TCR) gene rearrangement, suggestive of an oligoclonal response to a small number of antigenic peptides. A significant increase in the usage of the V alpha 2.3 TCR family by activated but not by non-activated CD4+ PBL was detected in patients (3.9% versus 3.4%) (P < 0.05) compared with controls. There was evidence of oligoclonal activation of CD4+ PBL in 11/30 patients (36.7%) but in none of the controls (n = 10). However, different V alpha or V beta TCR families were selectively activated among and even within individual patients. The heterogeneity in TCR expression among patients with active intraocular inflammatory disease is discussed.
authors.affiliation: Department of Clinical Ophthalmology, Institute of Ophthalmology, London, UK.
authors.forename: E J
authors.initials: EJ
authors.lastname: Feron
authors.forename: V L
authors.initials: VL
authors.lastname: Calder
authors.forename: S L
authors.initials: SL
authors.lastname: Lightman
mesh_terms: D001327:Autoimmune Diseases / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D005455:Fluorescent Antibody Technique; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis* / Q000276:immunology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000096:biosynthesis / Q000276:immunology; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis* / Q000276:immunology; D015866:Uveitis, Posterior / Q000276:immunology*
chemical_list: D007376:Interleukin-2; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D015375:Receptors, Interleukin-2