title: Inhibitory effects of small-molecule CCR5 antagonists on human immunodeficiency virus type 1 envelope-mediated membrane fusion and viral replication.
abstract: We established a human immunodeficiency virus type 1 (HIV-1) envelope (Env)-mediated membrane fusion assay and examined the small-molecule CCR5 antagonist TAK-779 and its derivatives for their inhibitory effects on HIV-1 Env-mediated membrane fusion and viral replication. The membrane fusion assay is based on HIV-1 long terminal repeat-directed beta-D-galactosidase reporter gene expression in CD4- and CCR5-expressed HeLa (MAGI-CCR5) cells after cocultivation with effector 293T cells expressing HIV-1 Env. Inhibition of HIV-1 replication was also determined in MAGI-CCR5 cells infected with the corresponding cell-free HIV-1. TAK-779 effectively suppressed R5 HIV-1 (strain JR-FL) Env-mediated membrane fusion as well as viral replication. Its 50% inhibitory concentrations (IC(50)s) for membrane fusion and viral replication were 0.87 +/- 0.11 and 1.4 +/- 0.1 nM, respectively. These values corresponded well to the IC(50) for (125)I-RANTES (regulated on activation, T cell expressed, and secreted) binding to CCR5 (1.4 nM). The inhibitory effects of 18 TAK-779 derivatives on membrane fusion differed from one compound to another. However, there was a close correlation among their inhibitory effects on membrane fusion, viral replication, and RANTES binding. The correlation coefficient between their IC(50)s for membrane fusion and viral replication was 0.881. Furthermore, since this assay depends on Env expressed in the effector cells, it is also applicable to the evaluation of CXCR4 antagonists. These results indicate that the HIV-1 Env-mediated membrane fusion assay is a useful tool for the evaluation of entry inhibitors.
authors.affiliation: Division of Human Retroviruses, Center for Chronic Viral Diseases, Faculty of Medicine, Kagoshima University, Kagoshima 890-8520, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Takashima
authors.forename: H
authors.initials: H
authors.lastname: Miyake
authors.forename: R A
authors.initials: RA
authors.lastname: Furuta
authors.forename: J I
authors.initials: JI
authors.lastname: Fujisawa
authors.forename: Y
authors.initials: Y
authors.lastname: Iizawa
authors.forename: N
authors.initials: N
authors.lastname: Kanzaki
authors.forename: M
authors.initials: M
authors.lastname: Shiraishi
authors.forename: K
authors.initials: K
authors.lastname: Okonogi
authors.forename: M
authors.initials: M
authors.lastname: Baba
mesh_terms: D000577:Amides / Q000494:pharmacology*; D019380:Anti-HIV Agents / Q000494:pharmacology*; D065100:CCR5 Receptor Antagonists; D018946:Chemokine CCL5 / Q000378:metabolism; D015696:Gene Products, tat / Q000096:biosynthesis; D015497:HIV-1 / Q000187:drug effects*; D006367:HeLa Cells; D006801:Humans; D008561:Membrane Fusion / Q000187:drug effects*; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000821:virology; D014759:Viral Envelope Proteins / Q000502:physiology*; D014779:Virus Replication / Q000187:drug effects*; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D000577:Amides; D019380:Anti-HIV Agents; D065100:CCR5 Receptor Antagonists; D018946:Chemokine CCL5; D015696:Gene Products, tat; D000644:Quaternary Ammonium Compounds; D014759:Viral Envelope Proteins; D054322:tat Gene Products, Human Immunodeficiency Virus; C119369:TAK 779