SIV-NEUTRALIZING AND HIV-2-NEUTRALIZING ANTIBODIES IN INFECTED MACAQUES MEASURED BY A NOVEL AND SIMPLE NEUTRALIZATION TEST BASED ON A NONCOMMERCIAL ANTIGEN-ELISA

A method for the measurement of neutralising antibodies (nab) directed against SIVmac or HIV-2 was developed. The assay is based on antigen detection using a non-commercial enzyme-linked immunosorbent assay (EL ISA). Studies were carried out to determine the influence of the test conditions on the nab titre. The sensitivity of the assay depended mai nly on the virus dose and the length of incubation of the serum-virus- mixture. Prolongation of the culture time from 9 to 11 days increased the validity of the results. Applying this neutralisation assay on seq uential serum samples from SIVmac- or HIV-2ben-infected macaques, a co nsiderable variation was found in nab titres between individual animal s. Whereas after infection with SIVmac, in vitro-neutralisation seems to correlate with protection against disease, and the lower pathogenit y of HIV-2ben in macaques compared with SIVmac is not due to the diffe rences in nab titres.