title: A new antigen scanning strategy for monitoring HIV-1 specific T-cell immune responses.
abstract: Delineation of the immune correlates of protection in natural infection or after vaccination is a mandatory step for vaccine development. Although the most recent techniques allow a sensitive and specific detection of the cellular immune response, a consensus on the best strategy to assess their magnitude and breadth is yet to be reached. Within the AIDS Vaccine Integrated Project (AVIP http://www.avip-eu.org) we developed an antigen scanning strategy combining the empirical-based approach of overlapping peptides with a vast array of database information. This new system, termed Variable Overlapping Peptide Scanning Design (VOPSD), was used for preparing two peptide sets encompassing the candidate HIV-1 vaccine antigens Tat and Nef. Validation of the VOPSD strategy was obtained by direct comparison with 15mer or 20mer peptide sets in a trial involving six laboratories of the AVIP consortium. Cross-reactive background responses were measured in 80 HIV seronegative donors (HIV-), while sensitivity and magnitude of Tat and Nef-specific T-cell responses were assessed on 90 HIV+ individuals. In HIV-, VOPSD peptides generated background responses comparable with those of the standard sets. In HIV-1+ individuals the VOPSD pools showed a higher sensitivity in detecting individual responses (Tat VOPSD vs. Tat 15mers or 20mers: p≤0.01) as well as in generating stronger responses (Nef VOPSD vs. Nef 20mers: p<0.001) than standard sets, enhancing both CD4 and CD8 T-cell responses. Moreover, this peptide design allowed a marked reduction of the peptides number, representing a powerful tool for investigating novel HIV-1 candidate vaccine antigens in cohorts of HIV-seronegative and seropositive individuals.
authors.affiliation: San Raffaele Scientific Institute, Milan, Italy. malnati.mauro@hsr.it
authors.forename: Mauro S
authors.initials: MS
authors.lastname: Malnati
authors.forename: Silvia
authors.initials: S
authors.lastname: Heltai
authors.forename: Antonio
authors.initials: A
authors.lastname: Cosma
authors.forename: Peter
authors.initials: P
authors.lastname: Reitmeir
authors.forename: Simone
authors.initials: S
authors.lastname: Allgayer
authors.forename: Richard H
authors.initials: RH
authors.lastname: Glashoff
authors.forename: Walter
authors.initials: W
authors.lastname: Liebrich
authors.forename: Eftyhia
authors.initials: E
authors.lastname: Vardas
authors.forename: Nesrina
authors.initials: N
authors.lastname: Imami
authors.forename: Samantha
authors.initials: S
authors.lastname: Westrop
authors.forename: Silvia
authors.initials: S
authors.lastname: Nozza
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Tambussi
authors.forename: Stefano
authors.initials: S
authors.lastname: Buttò
authors.forename: Emanuele
authors.initials: E
authors.lastname: Fanales-Belasio
authors.forename: Barbara
authors.initials: B
authors.lastname: Ensoli
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Ensoli
authors.forename: Antonella
authors.initials: A
authors.lastname: Tripiciano
authors.forename: Claudio
authors.initials: C
authors.lastname: Fortis
authors.forename: Paolo
authors.initials: P
authors.lastname: Lusso
authors.forename: Guido
authors.initials: G
authors.lastname: Poli
authors.forename: Volker
authors.initials: V
authors.lastname: Erfle
authors.forename: Harvey
authors.initials: H
authors.lastname: Holmes
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology*; D000595:Amino Acid Sequence; D000941:Antigens / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D030562:Databases, Protein; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology; D012680:Sensitivity and Specificity; D020539:Sequence Analysis, Protein / Q000379:methods
chemical_list: D016915:AIDS Vaccines; D000941:Antigens; D018984:Epitopes, T-Lymphocyte; D010455:Peptides; D007371:Interferon-gamma