<prompt> All are true regarding interleukin-1 except ?Primary source is monocyte-macrophage systemEndogenous pyrogensInhibit IL-2 production by T-cellsAll are true  <response>: Ans. is c i.e., Inhibit IL-2 production by T-cells Interleukin -1 Also known as leucocyte activating factor LAF or B cell activating factor BAF. Principally secreted by macrophages and monocytes; and epithelial cells. Other sources are B lymphocytes, fibroblasts and endothelial cells. Immunological effects- Activation of T cells for the production of IL - 2. B cell proliferation and antibody synthesis Neutrophil chemotaxis and increased PMN release from bone marrow. Increases body temperature impoant endogenous pyrogen. Bone marrow cell proliferation Induction of acute phase protein. 