Resting cell neutralization assay for HIV-1 primary isolates

A technique is described for detecting the activity of neutralizing polyclonal or monoclonal antibodies against HIV-1 primary isolates. Most commonly, neutralizing antibody activity for HIV-1 is assessed by quantifying the ability of antibodies to inhibit virus infection in mitogen-activated peripheral blood mononuclear cells or transformed lymphocytes. Because the target of HIV infection in vivo is neither a mitogen-activated nor a transformed cell, an assay using unstimulated peripheral blood mononuclear cells as a more physiologic target cell was developed. This "resting cell assay" mainly utilizes primary HIV-1 isolates that have been carried for only a few passages in vitro. The result is an assay that is more efficient to perform and that detects neutralizing activity with comparable or greater sensitivity than that previously described for assays of primary HIV-1 isolates.