Multisite comparison of anti-human immunodeficiency virus microbicide activity in explant assays using a novel endpoint analysis.
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.
Richardson-Harman
Nicola
N
Southern Research Institute, 431 Aviation Way, Frederick, MD 21701, USA.
Lackman-Smith
Carol
C
Fletcher
Patricia S
PS
Anton
Peter A
PA
Bremer
James W
JW
Dezzutti
Charlene S
CS
Elliott
Julie
J
Grivel
Jean-Charles
JC
Guenthner
Patricia
P
Gupta
Phalguni
P
Jones
Maureen
M
Lurain
Nell S
NS
Margolis
Leonid B
LB
Mohan
Swarna
S
Ratner
Deena
D
Reichelderfer
Patricia
P
Roberts
Paula
P
Shattock
Robin J
RJ
Cummins
James E
JE
D000890:Anti-Infective Agents / Q000494:pharmacology*; D002584:Cervix Uteri / Q000821:virology; D005260:Female; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods* / Q000592:standards*; D009092:Mucous Membrane / Q000821:virology; D014066:Palatine Tonsil / Q000821:virology; D012007:Rectum / Q000821:virology; D015203:Reproducibility of Results; D014779:Virus Replication / Q000187:drug effects
D000890:Anti-Infective Agents