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

Abstract

Summary: To investigate the protective efficacy of various gpl30 vaccine preparations, rhesus monkeys were immunized with gp130 oligomers (O-gp130) or two different gpl30-monomer preparations (M1-gpl30; M2-gp130) and challenged with 50 MID₅₀ of simian immunodeficiency virus (SIV)mac32H. Following challenge the control animals and all animals of the Ml- and M2-gp130 group and 1 animal of the O-gp130 group were productively infected, whereas 3 animals of the O-gp130 group resisted the productive virus replication. The protection was correlated with high neutralizing antibodies and a long-lasting immune response to the transmembrane protein gp41. Whereas none of the O-gp130 animals had developed disease symptoms, 3 M1-gpl30 animals, 1 M2-gpl30 animal, and 2 control animals died as a result of AIDS within 18 months after challenge. Therefore, immunization with virion-derived gp130 oligomers of SIVmac32H can confer protection against the productive infection with SIVmac32H and suppress the development of the AIDS-like disease.