title: A transcription inhibitor, actinomycin D, enhances HIV-1 replication through an interleukin-6-dependent pathway.
abstract: We previously demonstrated that Actinomycin D (ActD) enhanced HIV-1 replication in the MT-2 cell, a human T-cell leukemia virus type-1-infected cell line. The MT-2 cell is known to produce multiple cytokines spontaneously. In this study, we investigated the impact of ActD on the cytokine production from MT-2 cells and HIV-1 replication in a latently infected cell line, U1. MT-2 cells were pulse-treated with 0 or 200 nM of ActD, and culture supernatants were collected 3 days after incubation. Supernatants from untreated cells (Sup0) induced HIV-1 replication by 150-fold in U1 cells. Culture supernatants from ActD-treated cells (Sup200) enhanced HIV-1 replication by 1200-fold. A combination of a sequential chromatographic approach and mass spectrometric analysis identified that the HIV-inducing factors in Sup200 were interleukin (IL)-6 and tumor necrosis factor (TNF)-beta. Quantitative analysis revealed that ActD treatment increased the concentration of IL-6 in Sup200 by 600% compared with that in Sup0 but decreased the amount of TNFbeta in Sup200 by 85%. Northern blot analysis showed that ActD treatment increased IL-6 transcripts; however, no change was seen in TNFbeta transcripts. These results suggest that ActD induces replication of HIV-1 through modulation of cytokine production.
authors.affiliation: Laboratory of Human Retrovirology, Science Applications International Corporation (SAIC)-Frederick, Frederick, MD 21702-1201, USA. timamichi@niaid.nih.gov
authors.forename: Tomozumi
authors.initials: T
authors.lastname: Imamichi
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Conrads
authors.forename: Ming
authors.initials: M
authors.lastname: Zhou
authors.forename: Yuxin
authors.initials: Y
authors.lastname: Liu
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Adelsberger
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Veenstra
authors.forename: H Clifford
authors.initials: HC
authors.lastname: Lane
mesh_terms: D015152:Blotting, Northern; D002460:Cell Line; D002845:Chromatography; D003609:Dactinomycin / Q000494:pharmacology*; D016655:HIV Core Protein p24 / Q000032:analysis; D015497:HIV-1 / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis / Q000302:isolation & purification / Q000502:physiology*; D008233:Lymphotoxin-alpha / Q000032:analysis / Q000302:isolation & purification / Q000502:physiology; D013058:Mass Spectrometry; D012333:RNA, Messenger / Q000032:analysis; D013601:T-Lymphocytes / Q000821:virology; D014158:Transcription, Genetic / Q000187:drug effects; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D016655:HIV Core Protein p24; D015850:Interleukin-6; D008233:Lymphotoxin-alpha; D012333:RNA, Messenger; D003609:Dactinomycin