Interleukin-10 (IL-10) is an anti-inflammatory protein th at inhibits the expression of proinflammatory cytokines such as IL-1 and tumor necrosis factor-α (TNF-α). Like IL-4, IL-10 enhances humoral immune responses and attenuates cell-mediated immune reactions. It inhibits the production of IFN-γ and antigen-specific proliferation of type-1 T helper cells (Th1). It protects the host tissue from damage during immune responses. The protein has a role in modulating viral immunity. IL-10 enhances cytokine production, natural killer cell proliferation and cytotoxicity in vitro. IL-10 is an immunosuppressive cytokine. It promotes wound repair and functions to resolve inflammation in the central nervous system. IL-10 mediates its signaling function through the interleukin receptors namely, IL-10RA and two IL-10RBs. The expression of IL-10 is regulated by signal transducer and activator of transcription 3 (STAT3) and suppressor of cytokine signaling-3 (SOCS3) ratios. Polymorphisms in the IL-10 gene is implicated in breast cancer.
