Lackman-Smith Carol, Osterling Clay, Luckenbaugh Katherine, Mankowski Marie, Snyder Beth, Lewis Gareth, Paull Jeremy, Profy Albert, Ptak Roger G, Buckheit Robert W, Watson Karen M, Cummins James E, Sanders-Beer Brigitte E
Southern Research Institute, 431 Aviation Way, Frederick, Maryland 21701, USA.
Antimicrob Agents Chemother. 2008 May;52(5):1768-81. doi: 10.1128/AAC.01328-07. Epub 2008 Mar 3.
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.
局部用杀微生物剂是用于预防性传播病原体的自我给药产品。大量具有已知抗1型人类免疫缺陷病毒（HIV-1）抑制活性的化合物已被提议作为局部用杀微生物剂候选物。为了确定潜在的先导化合物，开发了一种体外筛选算法，以在评估细胞相关和无细胞HIV-1传播、进入和融合抑制的试验中评估候选杀微生物剂。该算法通过在一系列确定的试验中进行评估来推进化合物，这些试验产生相对抗病毒效力的测量值以确定推进或失败。初始测试包括在CD4依赖性CCR5嗜性细胞相关传播抑制试验和CD4/CCR5介导的HIV-1进入试验中双重测定抑制活性。通过重复测试确认活性，并将鉴定出的活性物质推进到二级筛选，以确定它们在存在或不存在CD4的情况下对CXCR4嗜性病毒传播的影响以及它们抑制CXCR4和CCR5嗜性包膜介导的细胞间融合的能力。此外，还在人精浆存在下、在pH值从4到7转变的试验中以及对相关乳酸杆菌菌株的生长抑制方面对确认的活性化合物进行评估。然后可以推进先导化合物进行专门测试，包括在人宫颈外植体和外周血单核细胞中针对主要HIV亚型的测定、与其他抑制剂的联合测试以及额外的细胞毒性试验。目前正在人体临床试验中评估的两种杀微生物剂产品PRO 2000和SPL7013（VivaGel的活性成分）在此体外算法中进行了测试，并显示对CCR5和CXCR4嗜性HIV-1感染具有高活性。
