Multisite comparison of anti-human immunodeficiency virus microbicide activity in explant assays using a novel endpoint analysis

Nicola Richardson-Harman, Carol Lackman-Smith, Patricia S. Fletcher, Peter A. Anton, James W. Bremer, Charlene S. Dezzutti, Julie Elliott, Jean-Charles B. Grivel, Patricia Guenthner, Phalguni Gupta, Maureen Jones, Nell S. Lurain, Leonid B. Margolis, Swarna Mohan, Deena Ratner, Patricia Reichelderfer, Paula Roberts, Robin J. Shattock, James E. Cummins

Research output: Contribution to journalArticle

34 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)3530-3539
Number of pages10
JournalJournal of Clinical Microbiology
Issue number11
Publication statusPublished - Nov 2009
Externally publishedYes


ASJC Scopus subject areas

  • Microbiology (medical)

Cite this

Richardson-Harman, N., Lackman-Smith, C., Fletcher, P. S., Anton, P. A., Bremer, J. W., Dezzutti, C. S., Elliott, J., Grivel, J-C. B., Guenthner, P., Gupta, P., Jones, M., Lurain, N. S., Margolis, L. B., Mohan, S., Ratner, D., Reichelderfer, P., Roberts, P., Shattock, R. J., & Cummins, J. E. (2009). Multisite comparison of anti-human immunodeficiency virus microbicide activity in explant assays using a novel endpoint analysis. Journal of Clinical Microbiology, 47(11), 3530-3539.