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 CD142+CD16+ and CD14+CD16+ phenotypes, and on CD4+CD25high 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.