title: Stimulation of HIV replication in mononuclear phagocytes by leukemia inhibitory factor.
abstract: This study examined the effects of leukemia inhibitory factor (LIF) on human immunodeficiency virus (HIV) replication in mononuclear phagocytes (MNP). LIF induced a dose-dependent increase in p24 antigen production in the chronically infected promonocytic cell line U1. The magnitude and time kinetics of the LIF effects were similar to interleukin 1 (IL-1), IL-6, and tumor necrosis factor (TNF), other cytokines known to induce HIV replication in this cell line. To characterize mechanisms responsible for these LIF effects, levels of HIV mRNA, activation of the DNA binding protein nuclear factor (NF)-kB, signal transduction pathways, and potential interactions with other cytokines were analyzed. LIF increased steady-state levels of HIV mRNA at 2.0, 4.3, and 9.2 kB. This was detectable by 24 h and persisted until 72 h. The DNA binding protein NF-kB is a central mediator in cytokine activation of HIV transcription. NF-kB levels were higher in unstimulated U1 cells as compared to the parent cell line U937. In both cell lines LIF increased NF-kB activity. Induction of NF-kB and HIV replication by cytokines are at least in part dependent on reactive oxygen intermediates. The oxygen radical scavenger N-acetyl-L-cysteine, but not an inhibitor of nitric oxide synthase, inhibited LIF-induced HIV replication. LIF induces the production of other cytokines in monocytes but its effects on HIV replication were not inhibited by antibodies to IL-1, TNF, or IL-6. These results identify LIF as a stimulus of HIV replication.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, University of California, San Diego, La Jolla.
authors.forename: S
authors.initials: S
authors.lastname: Broor
authors.forename: A B
authors.initials: AB
authors.lastname: Kusari
authors.forename: B
authors.initials: B
authors.lastname: Zhang
authors.forename: P
authors.initials: P
authors.lastname: Seth
authors.forename: D D
authors.initials: DD
authors.lastname: Richman
authors.forename: D A
authors.initials: DA
authors.lastname: Carson
authors.forename: W
authors.initials: W
authors.lastname: Wachsman
authors.forename: M
authors.initials: M
authors.lastname: Lotz
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001483:Base Sequence; D002460:Cell Line; D016207:Cytokines / Q000494:pharmacology; D017931:DNA Primers / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D015683:Gene Products, gag / Q000235:genetics; D006131:Growth Inhibitors / Q000494:pharmacology*; D006678:HIV / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D016655:HIV Core Protein p24 / Q000096:biosynthesis; D006801:Humans; D015850:Interleukin-6; D007700:Kinetics; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009000:Monocytes / Q000382:microbiology*; D016328:NF-kappa B / Q000096:biosynthesis; D009569:Nitric Oxide / Q000037:antagonists & inhibitors; D012333:RNA, Messenger / Q000096:biosynthesis; D015398:Signal Transduction; D014158:Transcription, Genetic; D014779:Virus Replication / Q000187:drug effects*; D019323:omega-N-Methylarginine
chemical_list: D016207:Cytokines; D017931:DNA Primers; D015683:Gene Products, gag; D006131:Growth Inhibitors; D016655:HIV Core Protein p24; D015850:Interleukin-6; C507837:LIF protein, human; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines; D016328:NF-kappa B; D012333:RNA, Messenger; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine; D000111:Acetylcysteine