title: Imaging-based assay for identification and characterization of inhibitors of CXCR4-tropic HIV-1 envelope-dependent cell-cell fusion.
abstract: Infection of certain cell types by HIV results in formation of syncytia. This process can be blocked by antibodies or compounds that prevent interaction of viral envelope protein with host cell receptors. Here the authors describe an automated imaging-based assay for inhibitors of cell-cell fusion mediated by interaction of HIV gp120 with CXCR4 coreceptor. The assay quantifies syncytia formation between U87MG astrocytoma cells constitutively expressing CD4/CXCR4 and morphologically distinct Jurkat T lymphoma cells inducibly expressing HIV env. Each cell type was differentially labeled with vital dyes. Fusion was quantified by measuring size, shape, and color of Jurkat cells and Jurkat-harboring cell syncytia. Dose-response experiments with reference inhibitors AMD 3100 and KRH-1636 yielded potencies consistent with those obtained using standard antiviral assays. This assay complements virus-based infectivity assays for identification of inhibitors of membrane fusion events triggered by interaction of HIV gp120 with host CXCR4.
authors.affiliation: Merck Research Laboratories, Department of Infectious Diseases, Kenilworth, NJ, USA. Susanne.Kramer@spcorp.com
authors.forename: Susanne
authors.initials: S
authors.lastname: Kramer
authors.forename: Peter
authors.initials: P
authors.lastname: Buontempo
authors.forename: Sony
authors.initials: S
authors.lastname: Agrawal
authors.forename: Robert
authors.initials: R
authors.lastname: Ralston
mesh_terms: D000818:Animals; D002460:Cell Line; D015726:Giant Cells / Q000187:drug effects*; D015699:HIV Envelope Protein gp120 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D023581:HIV Fusion Inhibitors / Q000494:pharmacology*; D015497:HIV-1 / Q000187:drug effects* / Q000378:metabolism; D057166:High-Throughput Screening Assays; D006801:Humans; D007091:Image Processing, Computer-Assisted; D019169:Jurkat Cells; D019718:Receptors, CXCR4 / Q000378:metabolism*; D054852:Small Molecule Libraries / Q000494:pharmacology
chemical_list: D015699:HIV Envelope Protein gp120; D023581:HIV Fusion Inhibitors; D019718:Receptors, CXCR4; D054852:Small Molecule Libraries