AEGiS-14IAC: V3 Antibodies and Heteroduplex Mobility Assay results in HIV-1 Infected Individuals from Venezuela.

14th International AIDS Conference

Barcelona, Spain - July 7-12, 2002

V3 Antibodies and Heteroduplex Mobility Assay results in HIV-1 Infected Individuals from Venezuela.

Int Conf AIDS 2002 Jul 7-12; 14:(abstract no. A10011)

Castro E, Bongertz V, Deibis L, Morgado M, Echeverria de Perez G
Instituto de Inmunologia, Universidad Central de Venezuela, Caracas, Venezuela

BACKGROUND: High diversity of HIV-1 M group has lead to the description of ten distinct subtypes and 12 circulating recombinant forms (CRFs), including the CRF12 _BF detected in South American countries. Enough evidence has been collected towards the identification of the third variable region (V3) of the envelope glycoprotein HIV-1/gp120 as the principal neutralizing domain (PND). Heterogeneous antibody reactivity in sera detected by V3 synthetic peptides has been associated with virus diversity.

OBJECTIVE: To investigate env antibody reactivity in HIV-1 isolates from Venezuela subtyped by heteroduplex mobility assay (HMA).

METHODS: V3 env antibodies to several syntethic peptides; A, B, Bbr, C, D, E, F, Fbr (Chiron Mimotopes, San Diego, Ca, USA) were assessed by ELISA, through an existing collaboration with the Oswaldo Cruz Institute. Plasma from 39 HIV-1 infected individuals (30% women and 70% men) was screened. For HIV-1 subtype exploration, nested PCR isolates obtained of env analysis with second round primer sets ED31-33 were studied by HMA (NIH AIDS Research and Reference Reagent Program).

RESULTS: As expected, a high cross-reactivity to different V3 synthetic peptides was observed. However, major antibody reactivity was present to peptides V3Bbr (37/39) and V3Fbr (32/39). Sixteen of 39 plasma (38.5%) reacted to V3B. Two samples (5%) were negative to all peptides. HIV-1 subtyping by HMA showed 92.3% (36/39) to be clade B and 7.7% (3/39) failed the PCR amplification after several attempts. The 3 non-amplified samples were studied by env sequencing and phylogenetic analysis, resulting in B clade as well.

CONCLUSIONS: These results show a higher recognition of B virus circulating in our area by V3Bbr and V3Fbr peptides that by V3B. Such observation could be related to the presence of mosaic genomes among the env B population viruses. This assumption would be consistent with CRF12 _BF previous descriptions in our region and also in Venezuela.

Keywords: AEGIS, HIV-1, Polymerase Chain Reaction, Enzyme-Linked Immunosorbent Assay, Venezuela, Peptides, Immunoglobulin Variable Region, Human, Female, Male, immunology

020707
A10011