AEGiS-07IAC: Characterization of human antibody binding sites on the HIV-2 external envelope.

7th International AIDS Conference


Florence, Italy — June 16-21, 1991

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Characterization of human antibody binding sites on the HIV-2 external envelope.

Int Conf AIDS 1991 Jun 16-21; 7:39 (abstract no. M.A.69)
deWolf F, Meloen RH, Bakker M, Barin F, Goudsmit J; Human Retrovirus Laboratory, University of Amsterdam, The Netherlands

OBJECTIVE: To map linear antibody binding sites on the HIV-2 external glycoprotein (EGP) gp125 and to study antibody reactivity to the most antigenic epitopes in sera of HIV-1- and HIV-2-infected individuals.

METHODS: HIV-2 immunoblot positive sera from 8 patients were used for antibody-reactive peptide scanning (PEPSCAN) using overlapping nonapeptides derived from the EGP of HIV-2Rod. Peptides representing PEPSCAN selected regions were synthesized and antibody-reactivity to these peptides was measured in sera from 26 HIV-2 positive African and European individuals, 64 HIV-1 positive Africans and 55 Dutch homosexual men, as well as 49 HIV-1/-2 negative African and 48 Dutch controls.

RESULTS: Fifteen antibody-binding regions were identified, among which 2 amino terminal regions (E3,aa118-132; E4,aa125-141) and 4 carboxyl terminal regions (E11,aa303-324; E12,aa340-358; E14,aa436-452; E15,aa486-507) were the most antigenic. E3 and E4 are highly variable domains across SIV, HIV-2 and HIV-1, E14 and E15 are highly conserved among HIV-2 strains, and had more aa's in common with SIV than with HIV-1. Sera of HIV-2 infected individuals bound the E11 and E15 peptides best (31%). The sera of HIV-1 infected Africans showed the highest levels of cross-reactivity to the HIV-2 peptides, while this was low in HIV-1-positive European sera. Using peptides covering the E15 epitope of HIV-1 and SIV, African HIV-2 positive sera showed cross-reactivity to E15 of HIV-1 and SIV.

CONCLUSIONS: 1) The immunodominant regions of the HIV-2 EGP (E11 and E15) align with those of HIV-1, 2. The frequency with which the African HIV-1 positive sera react to the HIV-1 E15 domain is similar to that for the European sera, but African sera frequently cross-react to the SIV and HIV-2 E15 domains, showing only modest primary aa-conservation.

Keywords: AEGIS, HIV-2, HIV-1, Binding Sites, Antibody, SIV, Epitopes, Immunodominant Epitopes, Peptides, Human, Male, immunology, ICA7KWDaegis,hiv-2,hiv-1,bindingsites,antibody,siv,epitopes,immunodominantepitopes,peptides,human,male,immunology,ica7
910616
MA69

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