title: Successful isolation of infectious and high titer human monocyte-derived HIV-1 from two subjects with discontinued therapy.
abstract: BACKGROUND
  HIV-1 DNA in blood monocytes is considered a viral source of various HIV-1 infected tissue macrophages, which is also known as "Trojan horse" hypothesis. However, whether these DNA can produce virions has been an open question for years, due to the inability of isolating high titer and infectious HIV-1 directly from monocytes.
  
  
  RESULTS
  In this study, we demonstrated successful isolation of two strains of M-HIV-1 (1690 M and 1175 M) from two out of four study subjects, together with their in vivo controls, HIV-1 isolated from CD4+ T-cells (T-HIV-1), 1690 T and 1175 T. All M- and T- HIV-1 isolates were detected CCR5-tropic. Both M- HIV-1 exhibited higher levels of replication in monocyte-derived macrophages (MDM) than the two T- HIV-1. Consistent with our previous reports on the subject 1175 with late infection, compartmentalized env C2-V3-C3 sequences were identified between 1175 M and 1175 T. In contrast, 1690 M and 1690 T, which were isolated from subject 1690 with relatively earlier infection, showed homogenous env C2-V3-C3 sequences. However, multiple reverse transcriptase (RT) inhibitor resistance-associated variations were detected in the Gag-Pol region of 1690 M, but not of 1690 T. By further measuring HIV DNA intracellular copy numbers post-MDM infection, 1690 M was found to have significantly higher DNA synthesis efficiency than 1690 T in macrophages, indicating a higher RT activity, which was confirmed by AZT inhibitory assays.
  
  
  CONCLUSIONS
  These results suggested that the M- and T- HIV-1 are compartmentalized in the two study subjects, respectively. Therefore, we demonstrated that under in vitro conditions, HIV-1 infected human monocytes can productively release live viruses while differentiating into macrophages.
authors.affiliation: Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America.
authors.forename: Tong
authors.initials: T
authors.lastname: Wang
authors.forename: Younong
authors.initials: Y
authors.lastname: Xu
authors.forename: Haiying
authors.initials: H
authors.lastname: Zhu
authors.forename: Thomas
authors.initials: T
authors.lastname: Andrus
authors.forename: Sergei B
authors.initials: SB
authors.lastname: Ivanov
authors.forename: Charlotte
authors.initials: C
authors.lastname: Pan
authors.forename: Jazel
authors.initials: J
authors.lastname: Dolores
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Dann
authors.forename: Michael
authors.initials: M
authors.lastname: Zhou
authors.forename: Dominic
authors.initials: D
authors.lastname: Forte
authors.forename: Zihuan
authors.initials: Z
authors.lastname: Yang
authors.forename: Sarah
authors.initials: S
authors.lastname: Holte
authors.forename: Lawrence
authors.initials: L
authors.lastname: Corey
authors.forename: Tuofu
authors.initials: T
authors.lastname: Zhu
mesh_terms: D000595:Amino Acid Sequence; D015496:CD4-Positive T-Lymphocytes / Q000821:virology; D004789:Enzyme Activation; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015658:HIV Infections / Q000188:drug therapy / Q000821:virology; D054303:HIV Reverse Transcriptase / Q000235:genetics / Q000378:metabolism; D015497:HIV-1 / Q000145:classification / Q000302:isolation & purification* / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D009000:Monocytes / Q000821:virology*; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D019713:Receptors, CCR5 / Q000378:metabolism; D015728:Receptors, HIV / Q000378:metabolism; D056189:Viral Tropism / Q000235:genetics; D014779:Virus Replication; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000737:chemistry / Q000235:genetics; D054302:pol Gene Products, Human Immunodeficiency Virus / Q000737:chemistry / Q000235:genetics
chemical_list: D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments; D019713:Receptors, CCR5; D015728:Receptors, HIV; D054301:gag Gene Products, Human Immunodeficiency Virus; D054302:pol Gene Products, Human Immunodeficiency Virus; C514824:reverse transcriptase, Human immunodeficiency virus 1; D054303:HIV Reverse Transcriptase