AEGiS-08IAC: Genetically engineered HIV-like particles containing chimeric MN/LAI envelope glycoproteins can induce cross-neutralizing antibodies recognizing the IIIB and MN isolates.

8th International AIDS Conference

Amsterdam, Netherlands — July 19-24, 1992

Genetically engineered HIV-like particles containing chimeric MN/LAI envelope glycoproteins can induce cross-neutralizing antibodies recognizing the IIIB and MN isolates.

Int Conf AIDS 1992 Jul 19-24; 8:We52 (abstract no. WeD 1041)
Rovinski B, Cao SX, James O, Sia C, Zolla-Pazner S, Matthews T, Klein M; Connaught Centre for Biotechnology Research, Ontario, Canada.

OBJECTIVE: To develop an AIDS vaccine candidate consisting of genetically engineered noninfectious HIV-like particles capable of eliciting cross-reactive immune responses.

METHODS: Using the inducible human metallothionein IIa promoter, we engineered two HIV-1LAI-based expression vectors encoding heterologous sequences from the V3 loop of the MN isolate in addition to the neutralization epitope of the endogenous envelope. To this end, a synthetic oligomer encoding gp120 residues 306 to 328 of the V3 (MN) loop was inserted at two different positions within the HIV-1LAI env gene. The recombinant constructs were transfected into various mammalian cell lines, and expression of HIV-like particles was assessed by immunoprecipitation and immunoblotting analyses. Immunogenicity studies were carried out in mice and guinea-pigs with fully-assembled, envelope-containing particles isolated from the supernatants of stably engineered Vero cells transfected with recombinant vectors.

RESULTS: Expression studies revealed that insertion of the heterologous V3 (MN) loop segment at two different locations within the conserved region 2 (C2) of gp120LAI, either 173 or 242 residues away from the N-terminus of the mature subunit, resulted in the secretion of noninfectious, fully-assembled HIV-like particles containing chimeric LAI/MN envelope glycoproteins. Both V3 (LAI) and V3 (MN) loop epitopes were recognized by loop-specific neutralizing antibodies. Animal studies demonstrated that these particles are strongly immunogenic and elicit cross-neutralizing antibodies against the IIIB and MN isolates.

CONCLUSION: The HIV-1 env gene can be manipulated to design and genetically engineer structurally modified virus-like particles. Modifications of this nature can be incorporated into candidate AIDS vaccines to broaden the specificity of neutralizing antibodies.

Keywords: AEGIS, HIV, AIDS Vaccines, HIV Envelope Protein gp120, HIV Antibodies, HIV-1, Genes, env, Glycoproteins, HIV Envelope Protein gp41, Epitopes, HIV Envelope Protein gp160, Antibodies, Cell Line, HIV Seropositivity, Immunoblotting, Human, Animal, Mice, genetics, ICA8
920719
WeD1041