Differential Regulation of Interleukin-l2 (IL-l2), Tumor Necrosis Factor cy, and IL-1p Production in Human Myeloid Leukemia Cell Lines and Peripheral Blood Mononuclear Cells

Natural killer cell-stimulatory factor or interleukin-l2 (NKSF/ IL-12) was originally identified and purified from the conditioned medium of Epstein-Barr virus (EBV)-transformed B-cell lines. Phorbol diesters were observed to be potent stimulators of NKSF/IL-12 production from the B-cell lines. Although monocytes were found to be the major producers of NKSFIIL-12 in peripheral blood (PB) in response to lipopolysaccharide (LPS) or to Staphy/ococcus aureus, several myeloid leukemia cell lines tested did not produce detectable NKSF/IL-12 either constitutively or upon stimulation with phorbol diesters. However, three lines, ML-3, HL-60, and THP-1, responded to LPS with significant levels of NKSF/ IL-12 production, whereas S aureus was effective only on THP-1 cells. When the cell lines were preincubated with compounds known to induce them to differentiate, production of tumor necrosis factor a (TNFa) and IL-lfi was in most