Human thymic stromal lymphopoietin enhances expression of CD80 in human CD14+ monocytes/macrophages

Objective Human thymic stromal lymphopoietin (TSLP), an epithelial cell-derived cytokine, promotes inflammatory T helper type 2 cell (Th2) differentiation of naive CD4(+) T cells. TSLP is highly produced in keratinocytes of patients with atopic dermatitis and bronchial epithelia of patients with asthma and was thought to be a master switch for allergic inflammation. We sought to examine the effect of TSLP in human monocytes/macrophages. Methods The effect of TSLP on the expression of cell surface antigens (CD11c, CD16, CD54, CD80, CD86, and HLA-DR) in peripheral blood CD14(+) monocytes/macrophages was examined. Results TSLP enhanced the expression of CD80 in peripheral blood CD14(+) monocytes/macrophages but not that of other cell surface antigens. It was associated with an increased percentage of CD14(dim/-), CD80(+), CD11c(+), and HLA-DR+ cells, which was consistent with the increased differentiation of myeloid dendritic cells. Conclusions TSLP induces CD80 expression in human peripheral blood CD14(+) monocytes/macrophages; this indicates monocyte/macrophage activation. This may be associated with their differentiation into myeloid dendritic cells.