Oral glucocorticoid treatment decreases interleukin-10 receptor expression on peripheral blood leucocyte subsets

Glucocorticoids (GCS) are capable of stimulating the secretion of interleukin (IL)-10 by leucocytes; however, the potential of GCS to modulate leucocyte susceptibility to IL-10-mediated actions has not yet been studied. In the current paper, we performed a detailed cross-sectional analysis of IL-10 receptor (IL-10R) expression by CD4(+) and CD8(+) T cells, natural killer (NK) cells, monocytes and neutrophils. Next, we analysed the effects of short-term oral GCS treatment on surface IL-10R expression by various leucocyte subpopulations in asthmatic patients. All leucocyte subsets studied presented with substantial levels of surface IL-10R. The highest levels of IL-10R were found on monocytes, predominantly with CD14(2+)CD16(+) and CD14(+)CD16(+) phenotypes, and on CD4(+)CD25(high) T cells. In contrast, levels of IL-10R on CD8(+) T cells, NK cells and neutrophils were significantly lower and similar to each other in intensity. GCS treatment resulted in a significant decrease of IL-10R expression on all analysed peripheral blood leucocyte subsets. Our data suggest that down-regulation of IL-10R could counterbalance the otherwise suppressive action of GCS.