Southern Research Institute, 431 Aviation Way, Frederick, MD 21701, USA.
J Clin Microbiol. 2009 Nov;47(11):3530-9. doi: 10.1128/JCM.00673-09. Epub 2009 Sep 2.
Microbicide candidates with promising in vitro activity are often advanced for evaluations using human primary tissue explants relevant to the in vivo mucosal transmission of human immunodeficiency virus type 1 (HIV-1), such as tonsil, cervical, or rectal tissue. To compare virus growth or the anti-HIV-1 efficacies of candidate microbicides in tissue explants, a novel soft-endpoint method was evaluated to provide a single, objective measurement of virus growth. The applicability of the soft endpoint is shown across several different ex vivo tissue types, with the method performed in different laboratories, and for a candidate microbicide (PRO 2000). The soft-endpoint method was compared to several other endpoint methods, including (i) the growth of virus on specific days after infection, (ii) the area under the virus growth curve, and (iii) the slope of the virus growth curve. Virus growth at the assay soft endpoint was compared between laboratories, methods, and experimental conditions, using nonparametric statistical analyses. Intra-assay variability determinations using the coefficient of variation demonstrated higher variability for virus growth in rectal explants. Significant virus inhibition by PRO 2000 and significant differences in the growth of certain primary HIV-1 isolates were observed by the majority of laboratories. These studies indicate that different laboratories can provide consistent measurements of anti-HIV-1 microbicide efficacy when (i) the soft endpoint or another standardized endpoint is used, (ii) drugs and/or virus reagents are centrally sourced, and (iii) the same explant tissue type and method are used. Application of the soft-endpoint method reduces the inherent variability in comparisons of preclinical assays used for microbicide development.
具有良好体外活性的杀微生物候选物通常会被进一步用于评估，使用与人类免疫缺陷病毒 1 型（HIV-1）体内黏膜传播相关的人体原代组织外植体，如扁桃体、宫颈或直肠组织。为了比较候选杀微生物剂在组织外植体中的病毒生长或抗 HIV-1 功效，评估了一种新的软终点方法，以提供病毒生长的单一客观测量。该软终点的适用性在几种不同的离体组织类型中得到了证明，该方法在不同的实验室中进行，并用于候选杀微生物剂（PRO 2000）。该软终点方法与其他几种终点方法进行了比较，包括（i）感染后特定天数的病毒生长，（ii）病毒生长曲线下的面积，以及（iii）病毒生长曲线的斜率。使用非参数统计分析比较了实验室、方法和实验条件之间的测定软终点处的病毒生长。使用变异系数进行的内部测定变异性表明，直肠外植体中的病毒生长具有更高的变异性。PRO 2000 显著抑制病毒，以及某些原发性 HIV-1 分离株的生长差异，被大多数实验室观察到。这些研究表明，当（i）使用软终点或另一种标准化终点，（ii）药物和/或病毒试剂集中供应，以及（iii）使用相同的外植体组织类型和方法时，不同的实验室可以提供抗 HIV-1 杀微生物剂功效的一致测量。软终点方法的应用减少了用于杀微生物剂开发的临床前检测比较中的固有变异性。
