V3 loop core region serotyping of HIV-1 infected patients using the FHV epitope presenting system

• Published in: Journal of virological methods 1997, Vol.63 (1), p.121-127
• Main Authors: Schiappacassi, M., Buratti, E., D'Agaro, P., Ciani, L., Scodeller, E.S., Tisminetzky, S.G., Baralle, F.E.
• Format: Article
• Language: English
• Subjects: AIDS/HIV; Amino Acid Sequence; Biological and medical sciences; Capsid - genetics; Enzyme-Linked Immunosorbent Assay; Epitopes - genetics; Epitopes - immunology; FHV; Genetic Vectors; HIV Antibodies - blood; HIV Antibodies - classification; HIV Antibodies - immunology; HIV Antigens - genetics; HIV Antigens - immunology; HIV Envelope Protein gp120 - genetics; HIV Envelope Protein gp120 - immunology; HIV Infections - blood; HIV Infections - immunology; HIV Infections - virology; HIV-1; HIV-1 - classification; HIV-1 - genetics; HIV-1 - immunology; Humans; Immunodeficiencies; Immunodeficiencies. Immunoglobulinopathies; Immunopathology; Insect Viruses - genetics; Medical sciences; Molecular Sequence Data; Peptide Fragments - genetics; Peptide Fragments - immunology; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - immunology; RNA Viruses - genetics; Serotyping - methods; V3 loop serotyping
• ISSN: 0166-0934; 1879-0984
• DOI: 10.1016/S0166-0934(96)02120-9

We have reported recently a new epitope presenting system based on the Flock House Virus (FHV) capsid protein. The HIV-1 V3 loop core sequence IGPGRAF was inserted in different sites of this carrier molecule. Immunoreactivity experiments and molecular modelling consistently showed that the most reactive recombinant protein displayed the IGPGRAF sequence in a conformation which is most similar to that of a V3 loop reference structure. The same insertion site was then used to display the V3 loop apex sequences of six different HIV-1 isolates. Sera from 32 HIV-1 infected patients were examined for their reactivity to our chimeric proteins and the results were compared with those obtained using synthetic V3 loop peptides. The data obtained were confirmed by nested PCR amplification and direct sequencing of the patient's V3 loops. The results showed that the V3 loop serotyping using the FHV hybrid proteins, was more specific than that obtained using synthetic peptides. This system will therefore be a useful tool for the correct evaluation of the immune response against different V3 loop core sequences.