title: Characterization of a human monocyte cytotoxicity-inducing factor (MCF).
abstract: Recently, we reported a lymphokine, monocyte cytotoxicity-inducing factor (MCF), which is distinct from interferon-gamma (IFN-gamma). In this report, we provide further characterization of MCF. MCF is inactivated by chymotrypsin, but not trypsin, RNase, or DNase. The production of MCF is abolished in a dose-dependent manner by actinomycin D and is diminished by puromycin, and cycloheximide. Native MCF produced under serum-free conditions demonstrated charge heterogeneity with three species having isoelectric points at 2.7, 5.6, and 6.7 respectively, and two molecular weight species of 29 Kd and 14.7 Kd. MCF-activated monocytes were not only able to lyse both NK sensitive and resistant targets, but also secreted IL 1, but not TNF. In summary, MCF is a lymphokine distinct from TNF, IL 1, IL 2, the IFNs, and the CSFs, which is able to activate monocytes to lyse tumor targets.
authors.affiliation: Department of Internal Medicine, University of Texas Medical School, Houston.
authors.forename: C M
authors.initials: CM
authors.lastname: Jones
authors.forename: C A
authors.initials: CA
authors.lastname: Prince
authors.forename: R K
authors.initials: RK
authors.lastname: Shadduck
mesh_terms: D002918:Chymotrypsin / Q000494:pharmacology; D003601:Cytotoxicity Tests, Immunologic; D003609:Dactinomycin / Q000494:pharmacology; D006801:Humans; D006825:Hybridomas / Q000378:metabolism; D007375:Interleukin-1 / Q000096:biosynthesis; D007526:Isoelectric Point; D008222:Lymphokines / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D016215:Macrophage-Activating Factors; D008970:Molecular Weight; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D013601:T-Lymphocytes / Q000378:metabolism; D014415:Tunicamycin / Q000494:pharmacology
chemical_list: D007375:Interleukin-1; D008222:Lymphokines; D016215:Macrophage-Activating Factors; D011500:Protein Synthesis Inhibitors; D014415:Tunicamycin; D003609:Dactinomycin; D002918:Chymotrypsin