title: gp120-Independent infection of CD4(-) epithelial cells and CD4(+) T-cells by HIV-1.
abstract: Infection of CD4- cells by HIV-1 is well documented, but the mechanism responsible remains a matter of discussion. Previously we modified an HIV-1 virus strain, NL4-3, by deleting the Env proteins (gp41 and gp120) and inserting the enhanced green fluorescent protein (EGFP), and found that the Env(-) virus infects several types of CD4- cells. Here, we have prepared Env(-) virus from both the CD4- cell line, 293T, and the CD4+ cell lines, CEM and SUPT1, and found that HIV-1 Env(-) virus from either cell type is infectious for both CD4+ and several CD4- cell lines. Replication of HIV-1 Env(-) virus-infected cells was demonstrated by p24 gag protein assays and real-time reverse transcriptase polymerase chain reaction (RT-PCR) of the culture medium from infected cells. Virus collected from the HIV-1-Env(-) infected cultures proved infectious to several CD4- cell lines. Our results suggest that HIV-1 infects both CD4- and CD4+ cells using a gp120-independent mechanism. This infection mechanism may provide new explanations for HIV-1 latency and persistent infection in patients.
authors.affiliation: Division of Oral Biology and Medicine and University of California Los Angeles Dental Institute, UCLA School of Dentistry, Los Angeles, 90095-1668, USA.
authors.forename: Yen-Hung
authors.initials: YH
authors.lastname: Chow
authors.forename: Duan
authors.initials: D
authors.lastname: Yu
authors.forename: Jun-Ying
authors.initials: JY
authors.lastname: Zhang
authors.forename: Yiming
authors.initials: Y
authors.lastname: Xie
authors.forename: O Lu-Chen
authors.initials: OL
authors.lastname: Wei
authors.forename: Christopher
authors.initials: C
authors.lastname: Chiu
authors.forename: Mani
authors.initials: M
authors.lastname: Foroohar
authors.forename: Otto O
authors.initials: OO
authors.lastname: Yang
authors.forename: No-Hee
authors.initials: NH
authors.lastname: Park
authors.forename: Irvin S Y
authors.initials: IS
authors.lastname: Chen
authors.forename: Shen
authors.initials: S
authors.lastname: Pang
mesh_terms: D015704:CD4 Antigens / Q000032:analysis*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000821:virology*; D002460:Cell Line; D004847:Epithelial Cells / Q000276:immunology / Q000821:virology; D049452:Green Fluorescent Proteins; D015699:HIV Envelope Protein gp120; D015497:HIV-1 / Q000737:chemistry / Q000502:physiology*; D006801:Humans; D008164:Luminescent Proteins; D014779:Virus Replication
chemical_list: D015704:CD4 Antigens; D015699:HIV Envelope Protein gp120; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins