Functional studies of soluble low-affinity interleukin-2 receptors in rheumatoid synovial fluid.

摘要: Since abnormal regulation of interleukin-2 (IL-2) has been demonstrated in rheumatoid arthritis (RA), the functional role low-affinity soluble IL-2 receptors (sIL-2R) purified from RA synovial fluids (SF) was studied. Picomolar levels sIL-2R were detected SF using an enzyme-linked immunosorbent assay. Levels higher serum and patients than controls (P less 0.001) paired 0.01). Soluble IL-2R had estimated molecular weights 40-50 kd 80-100 by gel filtration analysis. The 80-100-kd peak is likely to be a dimer 40-50-kd peak, since single 45-kd found after elution sodium dodecyl sulfate-polyacrylamide gels. inhibitory activity for lymphocyte proliferation range, with anti-CD25 affinity column further analyzed. fractions did not interfere mitogen-stimulated lymphocytes or binding radiolabeled CTLL-2 cells, although direct demonstrated. range 25 nM, which similar human T cell clone, indicating that both are IL-2. We conclude concentration render them unable IL-2-related activities.