IL10 modulates the expression of cytokines, soluble mediators and cell surface molecules by cells of myeloid origin, with important consequences for their ability to activate and sustain immune and inflammatory responses. The effects of IL10 on cytokine production and function of human macrophages are generally similar to those on monocytes, although less pronounced (Moore et al. 2001).
IL10 inhibits expression of IL1R1 and IL-1RII (de Waal Malefyt et al. 1991, Jenkins et al. 1994, Dickensheets & Donnelly 1997).
Both transcriptional and posttranscriptional mechanisms have been implicated in the inhibitory effects of IL10 on cytokine and chemokine production (Bogdan et al. 1991, Clarke et al. 1998, Brown et al. 1996).
IL10 inhibits monocyte expression of MHC class II antigens, ICAM1 (CD54), CD80 (B7), CD86 (B7.2) and FCER2 (CD23), countering the induction of these molecules by IL-4 or IFNgamma (de Waal Malefyt et al. 1991, Ding et al. 1993, Kubin et al. 1994, Willems et al. 1994, Morinobu et al. 1996). Downregulated expression of these molecules significantly decreases the T cell-activating capacity of monocyte APCs (de Waal Malefyt et al. 1991, Fiorentino et al. 1991, Ding et al. 1993).