title: Development of a comprehensive human immunodeficiency virus type 1 screening algorithm for discovery and preclinical testing of topical microbicides.
abstract: Topical microbicides are self-administered, prophylactic products for protection against sexually transmitted pathogens. A large number of compounds with known anti-human immunodeficiency virus type 1 (HIV-1) inhibitory activity have been proposed as candidate topical microbicides. To identify potential leads, an in vitro screening algorithm was developed to evaluate candidate microbicides in assays that assess inhibition of cell-associated and cell-free HIV-1 transmission, entry, and fusion. The algorithm advances compounds by evaluation in a series of defined assays that generate measurements of relative antiviral potency to determine advancement or failure. Initial testing consists of a dual determination of inhibitory activity in the CD4-dependent CCR5-tropic cell-associated transmission inhibition assay and in the CD4/CCR5-mediated HIV-1 entry assay. The activity is confirmed by repeat testing, and identified actives are advanced to secondary screens to determine their effect on transmission of CXCR4-tropic viruses in the presence or absence of CD4 and their ability to inhibit CXCR4- and CCR5-tropic envelope-mediated cell-to-cell fusion. In addition, confirmed active compounds are also evaluated in the presence of human seminal plasma, in assays incorporating a pH 4 to 7 transition, and for growth inhibition of relevant strains of lactobacilli. Leads may then be advanced for specialized testing, including determinations in human cervical explants and in peripheral blood mononuclear cells against primary HIV subtypes, combination testing with other inhibitors, and additional cytotoxicity assays. PRO 2000 and SPL7013 (the active component of VivaGel), two microbicide products currently being evaluated in human clinical trials, were tested in this in vitro algorithm and were shown to be highly active against CCR5- and CXCR4-tropic HIV-1 infection.
authors.affiliation: Southern Research Institute, 431 Aviation Way, Frederick, Maryland 21701, USA. Lackmansmith@southernresearch.org
authors.forename: Carol
authors.initials: C
authors.lastname: Lackman-Smith
authors.forename: Clay
authors.initials: C
authors.lastname: Osterling
authors.forename: Katherine
authors.initials: K
authors.lastname: Luckenbaugh
authors.forename: Marie
authors.initials: M
authors.lastname: Mankowski
authors.forename: Beth
authors.initials: B
authors.lastname: Snyder
authors.forename: Gareth
authors.initials: G
authors.lastname: Lewis
authors.forename: Jeremy
authors.initials: J
authors.lastname: Paull
authors.forename: Albert
authors.initials: A
authors.lastname: Profy
authors.forename: Roger G
authors.initials: RG
authors.lastname: Ptak
authors.forename: Robert W
authors.initials: RW
authors.lastname: Buckheit
authors.forename: Karen M
authors.initials: KM
authors.lastname: Watson
authors.forename: James E
authors.initials: JE
authors.lastname: Cummins
authors.forename: Brigitte E
authors.initials: BE
authors.lastname: Sanders-Beer
mesh_terms: D000465:Algorithms; D000577:Amides / Q000494:pharmacology; D000813:Anilides / Q000494:pharmacology; D019380:Anti-HIV Agents / Q000494:pharmacology*; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D065100:CCR5 Receptor Antagonists; D015704:CD4 Antigens / Q000276:immunology; D002460:Cell Line; D004353:Drug Evaluation, Preclinical; D005663:Furans / Q000494:pharmacology; D015497:HIV-1 / Q000187:drug effects*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D020128:Inhibitory Concentration 50; D009282:Naphthalenesulfonates / Q000494:pharmacology; D011108:Polymers / Q000494:pharmacology; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D019718:Receptors, CXCR4 / Q000037:antagonists & inhibitors; D013854:Thioamides
chemical_list: D000577:Amides; D000813:Anilides; D019380:Anti-HIV Agents; D000891:Anti-Infective Agents, Local; D065100:CCR5 Receptor Antagonists; D015704:CD4 Antigens; D005663:Furans; D009282:Naphthalenesulfonates; C120231:PRO 2000; D011108:Polymers; D000644:Quaternary Ammonium Compounds; D019718:Receptors, CXCR4; D013854:Thioamides; C111216:UC 10; C119369:TAK 779; C100668:UC-781