BACKGROUND: Previously we described a system whereby human peripheral blood T cells stimulated for 8 days in a cytokine cocktail acquired effector function for contact-dependent induction of proinflammatory cytokines from monocytes. We termed these cells cytokine-activated (Tck) cells and found that the signalling pathways elicited in the responding monocytes were identical whether they were placed in contact with Tck cells or with T cells isolated from rheumatoid arthritis (RA) synovial tissue. METHODS: Here, using magnetic beads and fluorescence-activated cell sorting, we extensively phenotype the Tck effector cells and conclude that effector function resides within the CD4+CD45RO+, CCR7-, CD49dhigh population, and that these cells are derived from the effector memory CD4+ T cells in resting blood. RESULTS: After stimulation in culture, these cells produce a wide range of T-cell cytokines, undergo proliferation and differentiate to acquire an extensively activated phenotype resembling RA synovial T cells. Blocking antibodies against CD69, CD18, or CD49d resulted in a reduction of tumour necrosis factor-alpha production from monocytes stimulated with CD4+CD45RO+ Tck cells in the co-culture assay. Moreover, blockade of these ligands also resulted in inhibition of spontaneous tumour necrosis factor-alpha production in RA synovial mononuclear cell cultures. CONCLUSION: Taken together, these data strengthen our understanding of T-cell effector function, highlight the multiple involvement of different cell surface ligands in cell-cell contact and, provide novel insights into the pathogenesis of inflammatory RA disease.



Publication Date


Publication Title

Arthritis Res Ther





Organisational Unit

School of Biomedical Sciences


Antigens, CD, Arthritis, Rheumatoid, CD4-Positive T-Lymphocytes, Cell Lineage, Cells, Cultured, Cytokines, Flow Cytometry, Humans, Immunologic Memory, Lymphocyte Activation, Monocytes, Phenotype, Synovial Membrane, T-Lymphocyte Subsets