Expression and function of IL-10R in mononuclear cells from patients with systemic lupus erythematosus

Objective: To assess the expression and function of the receptor for interleukin-10 (IL-10R) in immune cells from patients with systemic Jupus erythematosus (SLE). Methods: We assessed the expression and function of IL-10R in peripheral blood mononuclear cells (PBMCs) from 19 SLE patients and 15 healthy controls. The expression of IL-10R was assessed by flow cytometry, and the function of this receptor was determined by analysing both the activation of Jak-1, Tyk-2, Stat-1, and Stat-3 (Western blot) and the induction of gene expression (cDNA array test of 242 genes of cytokines, apoptosis and intracellular signalling) upon stimulation with IL-10. Results: We found similar levels of IL-10R expression in SLE patients and controls. In addition, variable levels of Jak-1, Tyk-2, Stat-1, and Stat-3 activation were induced by IL-10 in PBMCs from SLE patients and controls, with no significant differences in protein phosphorylation or kinetics of activation. However, clear-cut differences in the gene expression induced through IL-10R were observed in SLE patients and controls, mainly in the genes involved in apoptosis and those encoding for cytokines and their receptors. Conclusions: Our data suggest that despite normal levels of IL-10R expression, and an apparent lack of abnormalities in the intracellular signals induced through this receptor, immune cells from SLE patients exhibit an aberrant pattern of gene expression induced through the IL-10R.