CD45RO+, CD4+ memory effector T cells were obtained from RA matching peripheral blood and synovial fluid. T cells were cultured for 1 week with OKT3 (0.01 μg/ml) and anti-CD28, as described in Materials and methods. Where indicated, the cultures contained saturating concentrations of anti-IFN-γ antibody and/or IL-4. Afterward, the cells were washed, rested for 2.5 days, and restimulated for 6 h with mitogen to assess intracellular cytokines by flow cytometry; 104 cells were analyzed for each sample. The percentage of cytokine-expressing cells for each sample is shown. Similar results were obtained in at least two independent experiments. No significant difference (P > 0.05) was observed in the percentage of synovial IL-4-producing effector cells in the absence or presence of anti-IFN-γ antibody and/or IL-4.