Open AccessCd28 expression on t cell subsets in vivo and cd28‐mediated t cell response in vitro in patients with rheumatoid arthritis
Author(s) -
Sfikakis Peter P.,
Zografou Amalia,
Viglis Vassilis,
IniotakiTheodoraki Aliki,
Piskontaki Ifigenia,
Tsokos George C.,
Sfikakis Paul,
ChoremiPapadopoulou Helen
Publication year - 1995
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.1780380512
Subject(s) - cd28 , t cell , cd8 , cd80 , immunology , interleukin 21 , medicine , synovial fluid , cytotoxic t cell , antigen , biology , immune system , in vitro , cd40 , pathology , biochemistry , alternative medicine , osteoarthritis
Objective . In view of the critical importance of the CD28–CD80 (B7/BB1) costimulatory pathway in antigen‐specific T cell activation and clonal expansion, we examined CD28 surface molecule expression in vivo, and T cell receptor/CD3‐mediated and B7/BB1‐costimulated T cell proliferation in vitro, in rheumatoid arthritis (RA). Methods . Two‐color immunofluorescence analyses of peripheral blood and synovial fluid–derived T cells, as well as 3 H‐thymidine incorporation assays, were performed. Results . In the peripheral blood of 31 patients with active, untreated RA, a mean of 91% (range 48–100%) of CD4+ and 46% (range 13–82%) of CD8+ T cell subsets were CD28+, which was not significantly lower than normal. Although an overall decrease in the number of T cells was not observed, the numbers of CD28+CD8+ T cells were significantly lower in RA patients (mean 233/μl, versus 292/μl in controls), and this decrease was more pronounced in patients with severe disease (mean 172/μl). CD28 expression on peripheral CD8+ T cells in RA patients, but not in healthy individuals, correlated inversely with T cell activation as assessed by HLA–DR antigen expression. In contrast to the peripheral blood, RA synovial fluid T cells were almost exclusively CD28+, suggesting that migration of CD28+CD8+ T cells to active sites of inflammation may occur. In vitro proliferative responses of peripheral blood T cells to B7/BB1 costimulation in the presence of mitogenic doses of anti‐CD3 monoclonal antibody were identical in patients with RA and healthy individuals. Conclusion . Functionally intact CD28+ T cells may contribute to the abnormal immunoregulation and joint inflammation in RA.