Background ζ-chain has an important role in T-lymphocyte activation, and decreased ζ-chain expression is common at the sites of chronic inflammation. The precise mechanism of the ζ-chain downregulation is not known. Our earlier data suggested that CD3 ζ-chain expression of T-lymphocytes isolated from patients with rheumatoid arthritis, was lower than that of the healthy donors (p <0.05), and tumor necrosis factor (TNF) modulated T cell activation during inflammation by regulating the amount of CD3ζ-chain expression via a Src-like adaptor protein (SLAP) dependent mechanism. Our objective was to study the effect of proinflammatory and anti-inflammatory cytokines on the ζ-chain expression.
Materials and Methods PBMCs were separated from whole-blood samples by density gradient centrifugation. Jurkat cells and PBMCs were cultured in RPMI supplemented with 10% fetal bovine serum. PBMCs were activated with anti-CD3 and anti-CD28 antibodies. Cells were treated with 20 and 80 ng/ml TNF, IL- 1, IL-2, IL-4, IL-6, IL-8, IL-10; IL-13, IL-17 and IL-35 for 24 hours or left untreated. ζ-chain expression was measured by Western blot and by flow cytometry.
Results IL-6, IL-8, IL-10, IL-13 and IL-17 downregulated CD3ζ-chain expression (p<0.05), similarly to TNF.
Conclusion Our present data indicate that both proinflammatory and anti-inflammatory cytokines may have a role on T-cell activation through regulating CD3ζ-chain expression.