title: Detection of CD4+ T cells harboring human immunodeficiency virus type 1 DNA by flow cytometry using simultaneous immunophenotyping and PCR-driven in situ hybridization: evidence of epitope masking of the CD4 cell surface molecule in vivo.
abstract: Human immunodeficiency virus type 1 (HIV-1) infection of T cells and cells of the monocyte/macrophage lineage requires a specific interaction between the CD4 antigen expressed on the cell surface and the HIV-1 external envelope glycoprotein (gp120). To study the association between HIV-1 infection and modulation of cell surface expression of the CD4 molecule in vivo, we examined the CD4+ T cells harboring proviral DNA obtained from HIV-1-infected individuals who had received no antiretroviral therapy for at least 90 days. Simultaneous immunophenotyping of CD4 cell surface expression and PCR-driven in situ hybridization for HIV-1 DNA were used to resolve the CD4+ T cells into distinct populations predicted upon the presence or absence of proviral DNA. Among the HIV-1-infected study subjects, the percentage of CD4+ T cells harboring proviral DNA ranged from 17.3 to 55.5%, with a mean of 40.5%. Cell surface fluorescent staining with anti-CD4 antibody directed against a non-gp120 binding site-related epitope (L120) or a conformation-dependent epitope of the gp120 binding site (Leu 3A) demonstrated either an equivalent or a 1.5- to 3-fold-lower cell surface staining intensity for the HIV-1 DNA-positive subpopulation relative to the HIV-1 DNA-negative subpopulation, respectively. These data suggest that masking or alteration of specific epitopes on the CD4 molecule occurs after viral infection.
authors.affiliation: Department of Medicine, Northwestern University Medical School, Chicago, Illinois 60611, USA.
authors.forename: B K
authors.initials: BK
authors.lastname: Patterson
authors.forename: C
authors.initials: C
authors.lastname: Goolsby
authors.forename: V
authors.initials: V
authors.lastname: Hodara
authors.forename: K L
authors.initials: KL
authors.lastname: Lohman
authors.forename: S M
authors.initials: SM
authors.lastname: Wolinsky
mesh_terms: D015704:CD4 Antigens / Q000032:analysis*; D015496:CD4-Positive T-Lymphocytes / Q000821:virology*; D002460:Cell Line; D004279:DNA, Viral / Q000032:analysis*; D000939:Epitopes; D005434:Flow Cytometry; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D016130:Immunophenotyping; D017403:In Situ Hybridization; D016133:Polymerase Chain Reaction; D011533:Proviruses / Q000235:genetics; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D015398:Signal Transduction
chemical_list: D015704:CD4 Antigens; D004279:DNA, Viral; D000939:Epitopes; D011948:Receptors, Antigen, T-Cell