A Cell Line Assay to Detect Neutralizing Antibodies against HIV-1 Primary and Prototypic Viruses

Abstract

A cell line assay to detect neutralizing antibodies against HIV-1 primary and prototypic isolates is described. The assay uses the human mega-glioblastoma astrocytic cell, U87-MG that has the stable expression of the human CD4 and either CXCR4 or CCR5 receptors. The results demonstrate that this cell line allows for entry and replication by all known HIV-1 isolates. Comparison of this target to other transformed cell lines, such CEM, H9, and MT-2 cells, shows that the U87-based assay is more consistent. The U87-based assay was also compared to the more traditional peripheral blood mononuclear cell (PBMC) assay, which utilizes primary HIV-1 isolates. Overall the PBMC assay was more sensitive than the 087 format. However, the 087-based cell assay is more consistent because the donor variability associated with PBMCs is eliminated. The U87-based assay allows for rapid and inexpensive setup and endpoint analysis. This proposed neutralization assay maybe used as a high throughput-screening assay for detecting neutralizing antibodies for individuals involved in a third phase clinical trial. This assay can be used to test vaccinee serum against both primary and prototypic HIV-1 isolates.