title: Serotyping HIV-1 with V3 peptides: detection of high avidity antibodies presenting clade-specific reactivity.
abstract: The main objective of the present study was to assess the specificity and sensitivity of a modified assay using short synthetic peptides of the V3 region of HIV-1 gp120, which is the main target for neutralizing antibodies. Results from an enzyme immunoassay (EIA) employing a panel of synthetic peptides of HIV-1 subtypes and using urea washes to detect high avidity antibodies (AAV3) were compared with those obtained by the heteroduplex mobility assay and DNA sequencing. The EIA correctly typed 100% of subtype B (sensitivity = 1.0; specificity = 0.95), 100% of HIV-1 E samples (sensitivity = 1.0; specificity = 1.0), and 95% of subtype C specimens (sensitivity = 0.95; specificity = 0.94). In contrast, only 50% of subtype A (sensitivity = 0.5; specificity = 0.95), 60% of subtype D (sensitivity = 0.6; specificity = 1.0), and 28% of subtype F samples (sensitivity = 0.28; specificity = 0.95) were correctly identified. This approach was also able to discriminate in a few samples antibodies from patients infected with B variants circulating in Brazil and Thailand that reacted specifically. The assays described in this study are relatively rapid and simple to perform compared to molecular approaches and can be used to screen large numbers of serum or plasma samples. Moreover, the classification in subtypes (genotypes) may overestimate HIV-1 diversity and a classification into serotypes, based on antigenic V3 diversity or another principal neutralization domain, may be more helpful for vaccine development and identification of variants.
authors.affiliation: Instituto de Infectologia Emílio Ribas, São Paulo, SP, Brasil.
authors.forename: J
authors.initials: J
authors.lastname: Casseb
authors.forename: D
authors.initials: D
authors.lastname: Katzenstein
authors.forename: M
authors.initials: M
authors.lastname: Winters
authors.forename: L F M
authors.initials: LF
authors.lastname: Brigido
authors.forename: A J S
authors.initials: AJ
authors.lastname: Duarte
authors.forename: R M
authors.initials: RM
authors.lastname: Hendry
mesh_terms: D000595:Amino Acid Sequence; D000915:Antibody Affinity; D001483:Base Sequence; D015483:HIV Antibodies / Q000097:blood / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology* / Q000821:virology; D015497:HIV-1 / Q000145:classification* / Q000276:immunology; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology*; D012680:Sensitivity and Specificity; D017385:Sequence Homology; D012703:Serotyping
chemical_list: D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments