Figure 3

CD4⁺CD28^null T cells from peripheral blood and synovial fluid show human cytomegalovirus specificity. (upper panel) The functional capacity of CD4⁺CD28^null T cells in peripheral blood (PB) and synovial fluid (SF) was investigated after stimulation of mononuclear cells from paired PB and SF from rheumatoid arthritis patients by plate-bound anti-CD3 antibodies. (lower panel) The reactivity of CD4⁺CD28^null T cells in paired PB and SF to human cytomegalovirus (HCMV) antigens was analysed after stimulation by the pp65 or immediate early (IE) antigens.