Method for detection of simian immunodeficiency virus neutralizing antibodies using a noncommercial antigen capture enzyme-linked immunosorbent assay.

A neutralization test (NT) using a noncommercial antigen capture enzyme-linked immunosorbent assay (ELISA) to detect simian immunodeficiency virus (SIV) growth in vitro was developed. The capture antibody was a mixture of purified macaque anti-SIV immunoglobulin G (IgG) and a monoclonal antibody to SIV p27. Captured antigens were detected by using purified macaque anti-SIV IgG conjugated to horseradish peroxidase. The NT reliably and sensitively detected differences when various amounts of SIV were used with positive and negative control macaque sera. Dilutions of sequential sera from a macaque (Macaca nemestrina) that had been experimentally infected with SIV were tested for neutralizing antibody with 300 50% tissue culture infective doses of SIV. In this macaque, neutralizing activity and anti-SIV IgG levels in serum (detected by ELISA) increased with time after SIV inoculation, and high IgG titers were required in serum before neutralization occurred in vitro. This simple NT, which detects the presence of SIV serum neutralizing antibodies at a low cost, will be useful for investigating the role of neutralizing antibodies in the SIV-infected macaque model for AIDS.