MCP-1 is selectively expressed in the late phase by cytokine-stimulated human neutrophils: TNF-alpha plays a role in maximal MCP-1 mRNA expression

Culture supernatants of phytohemagglutinin (PHA)-stimulated human periphera l blood mononuclear cells (PHA-sup) induced monocyte chemoattractant protei n-1 (MCP-1) mRNA expression in human neutrophjls. MCP-1 mRNA was first dete cted by Northern analysis at 8 h, and the peak level was detected at 16 h a nd sustained until 72 h. Cycloheximide and genistein, but not pertussis tox in, inhibited the expression of MCP-1 mRNA, Reecombinant tumor necrosis fac tor a (TNF-cx) induced a low level MCP-1 mRNA accumulation in neutrophils, and addition of anti-TNF-a IgG blocked 30-70% of MCP-1 mRNA expression indu ced with PHA-sup, PHA-sup-stimulated PMN synthesized and secreted 3.1 +/- 1 .3 ng/5 x 10(6) PMN MCP-1 within the first 24 h, Hybridization of P-32-labe led cDNA preparations to an array of human cytokine cDNAs further indicated that MCP-1 mRNA was selectively up-regulated in the late phase after stimu lation with the PHA-sup.