title: Unintegrated HIV-1 circular 2-LTR proviral DNA as a marker of recently infected cells: relative effect of recombinant CD4, zidovudine, and saquinavir in vitro.
abstract: Unintegrated HIV-1 proviral DNA is one of the earliest detectable forms of HIV-1, and the influence of an antiretroviral drug on its appearance may reflect the efficacy of that agent in preventing infection of new cells. We characterized the dynamics of HIV-1 p24 (p24) antigen production, HIV-1 gag DNA, tandem long-terminal-repeat circular unintegrated proviral (2-LTR) HIV-1 DNA, HIV-1 tat mRNA, and cell viability in the presence of three antiretroviral agents: recombinant soluble CD4 (rsCD4), zidovudine, and saquinavir. Interference with HIV-1 entry by rsCD4 decreased p24 antigen levels modestly, decreased HIV-1 gag by twofold, and 2-LTR was detectable at the end of the culture period. Inhibition of reverse transcription by zidovudine decreased p24 antigen levels modestly, decreased HIV-1 gag by 19-fold, and inhibited detection of 2-LTR HIV-1 DNA. The protease inhibitor, saquinavir, had the greatest overall effect, with the lowest levels of p24 antigen and HIV-1 gag, and inhibition of 2-LTR. There was no detection of tat mRNA in the saquinavir-treated cultures. In addition, cell viability was significantly higher in cultures treated with saquinavir. In these experiments, 2-LTR HIV-1 DNA was indicative of the relative inhibitory effects of three antiretroviral agents acting at different steps of the HIV-1 replication cycle. We demonstrated in vitro that 2-LTR HIV-1 DNA was a useful indicator of an antiretroviral drug in preventing new cell infection and could be utilized as a dynamic marker of drug efficacy in HIV-1-infected patients.
authors.affiliation: Department of Laboratory Medicine, University of Washington, Seattle 98195, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Panther
authors.forename: R W
authors.initials: RW
authors.lastname: Coombs
authors.forename: S A
authors.initials: SA
authors.lastname: Aung
authors.forename: C
authors.initials: C
authors.lastname: dela Rosa
authors.forename: D
authors.initials: D
authors.lastname: Gretch
authors.forename: L
authors.initials: L
authors.lastname: Corey
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology*; D015415:Biomarkers; D015704:CD4 Antigens / Q000494:pharmacology; D002460:Cell Line; D004279:DNA, Viral / Q000187:drug effects* / Q000235:genetics; D015696:Gene Products, tat / Q000378:metabolism; D016655:HIV Core Protein p24 / Q000378:metabolism; D017320:HIV Protease Inhibitors / Q000494:pharmacology; D015497:HIV-1 / Q000187:drug effects* / Q000502:physiology*; D016133:Polymerase Chain Reaction / Q000379:methods; D011533:Proviruses / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D012367:RNA, Viral / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000494:pharmacology; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology; D019258:Saquinavir / Q000494:pharmacology; D020079:Terminal Repeat Sequences / Q000187:drug effects* / Q000235:genetics; D016662:Virus Integration; D015215:Zidovudine / Q000494:pharmacology; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D019380:Anti-HIV Agents; D015415:Biomarkers; D015704:CD4 Antigens; D004279:DNA, Viral; D015696:Gene Products, tat; D016655:HIV Core Protein p24; D017320:HIV Protease Inhibitors; D012367:RNA, Viral; D011994:Recombinant Proteins; D018894:Reverse Transcriptase Inhibitors; D054322:tat Gene Products, Human Immunodeficiency Virus; D015215:Zidovudine; D019258:Saquinavir