Protection of Macaques Against SIV Infection by Subunit Vaccines of SIV Envelope Glycoprotein gp160

Abstract

Simian immunodeficiency virus (SIV) is a primate lentivirus related to human immunodeficiency viruses and is an etiologic agent for acquired immunodeficiency syndrome (AIDS)-like diseases in macaques. To date, only inactivated whole virus vaccines have been shown to protect macaques against SIV infection. Protective immunity was elicited by recombinant subunit vaccines. Four Macaca fascicularis were immunized with recombinant vaccinia virus expressing SIVmne gp160 and were boosted with gp160 produced in baculovirus-infected cells. All four animals were protected against an intravenous challenge of the homologous virus at one to nine animal-infectious doses. These results indicate that immunization with viral envelope antigens alone is sufficient to elicit protective immunity against a primate immunodeficiency virus. The combination immunization regimen, similar to one now being evaluated in humans as candidate human immunodeficiency virus (HIV)-1 vaccines, appears to be an effective way to elicit such immune responses.

Molecular and biological characterization of simian immunodeficiency virus macaque strain 32H proviral clones containing nef size variants

“…The anti-human cell antibodies from the protected monkeys seem to correlate with protection (Langlois et al, 1992). In a recent study, Hu & Benveniste (1992) have shown that a subunit vaccine prepared from the gpl60 of SIVmne can stimulate a protective response in macaques challenged with a homologous biological clone of SIVmne. However, in general these results have not yet been repeated by other groups using the SIVmac model.…”

Prospects for an HIV Vaccine: Conventional Approaches and DNA Immunization

“…Macaques immunized with a vaccinia vector harbouring HIV proteins have also elicited HIV-specific cellular and Immoral immune responses (I-1u et al, 1987;Shen et al, 1991). Futhermore, in another study in which macaques were immunized with a vaccinia vector harbouring the S IV gene encoding gp160, followed by a boost with recombinant SIV gp160, some monkeys showed protection from challenge with primary SIV isolates (Hu et al, 1992). Although these results are promising, studies in which live viral vector vaccines, such as vaccinia, had been administered to immunosuppressed individuals resulted in some individuals developing lifethreatening viral infections (Redfield et al, 1987).…”

True

“…Many of the principles of designing a human AIDS vaccine are currently being tested in the simian immunodeficiency virus model. 101 …”