Efficiency of infection of rheumatoid arthritis (RA) joint cell cultures. RA joint tissues were obtained from the synovium from patients with RA undergoing surgery. Cells were infected with Advβgal (moi 40) for 48 hours prior to analysis of the cells for βgal expression by fluorescence activated cell sorting (FACS). (B) Effect of IκBα transgene expression on cytokine expression in RA joint cell cultures. RA joint cells were infected with AdvIκBα or AdvO (moi 40). Culture supernatants were harvested after 48 hours and analysed for the expression of various cytokines by enzyme-linked immunosorbent assay. Data are representative of samples from at least five patients. IL-1RA, interleukin-1 receptor antagonist; TNF, tumour necrosis factor; sTNFR, soluble TNF receptor.