Expression and function of dectin-1 is defective in monocytes from patients with systemic lupus erythematosus and rheumatoid arthritis.

ABSTRACT

The aim of this work was to study the expression and function of the innate immune receptor dectin-1 in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). We studied twenty-six patients with SLE not receiving immunosuppressive therapy, twenty-six patients with RA, and fifteen controls. We found that monocytes from SLE patients showed a diminished expression of dectin-1 compared to healthy controls, and an inverse correlation between percent of dectin-1(+) cells and the disease activity score was detected. In addition, cells from SLE patients showed an abnormal calcium flux response induced by dectin-1 ligands as well as an enhanced release of IL-1ß, IL-6 and TNF-α, but not IL-23, upon dectin-1 engagement. Monocytes from patients with RA also showed a diminished expression, and a defective function of dectin-1. Our data suggest that dectin-1 receptor defects could contribute to the pathogenesis of autoimmune inflammatory conditions.