Prechallenge high neutralizing antibodies and long-lasting immune reactivity to gp41 correlate with protection of rhesus monkeys against productive simian immunodeficiency virus infection or disease development

To investigate the protective efficacy of various gp130 vaccine preparation s, rhesus monkeys were immunized with gp130 oligomers (O-gp130) or two diff erent gp130-monomer preparations (M1-gp130; M2-gp130) and challenged with 5 0 MID,, of simian immunodeficiency virus (SIV)mac32H. Following challenge t he control animals and all animals of the M1- and M2-gp130 group and I anim al of the O-gp130 group were productively infected, whereas 3 animals of th e O-gp130 group resisted the productive virus replication. The protection w as correlated with high neutralizing antibodies and a long-lasting immune r esponse to the transmembrane protein gp41. Whereas none of the O-gp130 anim als had developed disease symptoms, 3 M1-gp130 animals, I M2-gp130 animal, and 2 control animals died as a result of AIDS within 18 months after chall enge. Therefore, immunization with virion-derived gp130 oligomers of SIVmac 32H can confer protection against the productive infection with SIVmac32H a nd suppress the development of the AIDS-like disease.