Interleukin-10, or IL-10, is a 178 amino acid protein that is primarily secreted by TH2 clones. IL-10 is an anti-inflammatory cytokine that is produced by T cells, NK cells, and macrophages. The anti-inflammatory activity of IL-10 is due to its ability to block signaling through other cytokine receptors, notably IFN-γ receptor, by upregulating expression of SOCS1. In addition, IL-10 promotes T cell tolerance by inhibiting tyrosine phosphorylation of CD28. IL-10 expression has been shown to be elevated in HIV-1 infected individuals and has been implicated in the progression of the disease.
