title: Expression and function of CD5 and CD28 in patients with rheumatoid arthritis.
abstract: To assess the role of CD5 and CD28 in the pathogenesis of the decreased cellular immune function in patients with rheumatoid arthritis (RA) we analysed the expression and function of these T-cell surface molecules. The expression of CD5 as well as of CD28 in synovial and peripheral blood T cells was similar to that of control T cells. Monoclonal antibodies (mAb) directed at CD28 and CD5 were able to provide an accessory signal to anti-CD3 activated T cells both from the synovial fluid and from the peripheral blood. However, the proliferation induced by anti-CD3 mAb in conjunction with anti-CD5 or anti-CD28 mAb was always higher in peripheral blood (PB) T cells compared to the paired synovial fluid T cells. After simultaneous ligation of CD5 and CD28, proliferation was induced in the PB T cells. However, when compared to control PB T cells, this proliferation was significantly lower in the RA patients. Purified normal memory (CD45RO+) T cells proliferated less strongly than naive (CD45RA+) T cells, but no difference was observed between rheumatoid and normal memory T-cell proliferative responses. However, enriched PB CD45RA+ T cells from rheumatoid patients proliferated less vigorously to CD5 and CD28 ligation when compared to normal enriched CD45RA+ T cells. Synovial fluid (SF) T cells, which are mainly of the memory cell type, did not proliferate after simultaneous ligation of CD5 and CD28. This refractory state of synovial T cells could not be explained by a difference in the surface expression of CD5 or CD28. Our data suggest that the cellular immune dysfunction in the PB from rheumatoid patients may be due to a decreased responsiveness of the naive T-cell subset to accessory signals provided by CD5 and CD28. In addition, SF T cells appear hyporesponsive to stimulating signals provided through CD5 and CD28.
authors.affiliation: Department of Medicine, Guy's Hospital, London, U.K.
authors.forename: J
authors.initials: J
authors.lastname: Verwilghen
authors.forename: V
authors.initials: V
authors.lastname: Corrigall
authors.forename: R M
authors.initials: RM
authors.lastname: Pope
authors.forename: R
authors.initials: R
authors.lastname: Rodrigues
authors.forename: G S
authors.initials: GS
authors.lastname: Panayi
mesh_terms: D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000276:immunology*; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D018106:CD28 Antigens / Q000276:immunology*; D017252:CD3 Complex / Q000276:immunology; D018956:CD5 Antigens; D003432:Cross-Linking Reagents; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology; D011956:Receptors, Cell Surface / Q000276:immunology; D013582:Synovial Fluid / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018106:CD28 Antigens; D017252:CD3 Complex; D018956:CD5 Antigens; D003432:Cross-Linking Reagents; D011956:Receptors, Cell Surface