title: CD3+4-8-WT31-(T cell receptor gamma+) cells and other unusual phenotypes are frequently detected among spontaneously interleukin 2-responsive T lymphocytes present in the joint fluid in juvenile rheumatoid arthritis. A clonal analysis.
abstract: T lymphocytes (E rosetting cells) isolated from the joint fluid of four patients with juvenile rheumatoid arthritis (JRA) were first analyzed for surface antigen expression. Approximately 15% of cells were CD25+ (interleukin, IL, 2 receptor positive), in addition, a remarkable proportion of cells expressed the CD2+3- phenotype. CD3+ cells outnumbered the sum of CD4+ and CD8+ cells as well as the cells reactive with the WT31 monoclonal antibody (which recognizes a framework determinant of the alpha/beta T cell receptor). Purified T cells were cloned under culture conditions (1% phytohemagglutinin, PHA plus IL2) which allow clonal expansion of most peripheral blood T lymphocytes. Under these conditions proliferating cells ranged from 25 to 65%; clones (derived from microcultures containing 0.5 or 0.25 cells/well) were tested for cytolytic activity against P815 cells (in the presence of PHA) or against the natural killer (NK)-sensitive K562 target cells. Fifty-four percent and 73% of clones obtained from the two patients with the polyarticular form of the disease displayed cytolytic activity in the lectin-dependent assay. Cytolytic clones were 22 and 29% in the two patients with single joint involvement. About half of all cytolytic clones displayed NK-like activity. Surface antigen analysis revealed that, in addition to conventional CD3+4+8- and CD3+4-8+, a noticeable fraction of clones (50/202) displayed unusual surface phenotypes. In particular, 33/50 coexpressed CD4 and CD8 antigens; 7/50 were CD2+3-4-8- and displayed NK-like activity; 10/50 expressed CD3 but lacked both CD4 and CD8 antigen and did not react with the WT31 monoclonal antibody. In order to allow selective growth of IL2-responsive cells, T lymphocytes were also cloned directly in IL2. As much as 57% of all clones thus obtained (48/84) displayed cytolytic activity. Moreover, about half expressed unusual surface phenotypes including CD2+3-4-8-, CD3+4+8+ and CD3+4-8-WT31-. Given the accumulation at the site of the joint involvement of unusual T cells, most of which displayed cytolytic activity and were likely to represent cells activated in vivo (IL2 responsive), one may speculate that these cells may be involved in the injury process.
mesh_terms: D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D001171:Arthritis, Juvenile / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation; D012333:RNA, Messenger / Q000235:genetics; D011948:Receptors, Antigen, T-Cell / Q000032:analysis* / Q000235:genetics; D016692:Receptors, Antigen, T-Cell, gamma-delta; D013582:Synovial Fluid / Q000166:cytology / Q000276:immunology*; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000145:classification / Q000276:immunology
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D007376:Interleukin-2; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D016692:Receptors, Antigen, T-Cell, gamma-delta