<prompt> IL -1 produces -T lymphocyte activationDelayed wound healingIncreased pain perceptionDecreased PMN release from bone marrow  <response>: Ans. is a i.e., T-Iymphocyte activation . 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. 