Does interleukin inhibit or turn down the immune response?

Interleukins: One of a large group of proteins produced mainly by t cells and in some cases by mononuclear phagocytes or other cells. Interleukins participate in communication among leukocytes and are important in the inflammatory response. Most interleukins direct other cells to divide and differentiate. Each acts on a particular group of cells that have receptors specific to that interleukin.