title: A comparison of standard immunogenicity assays for monitoring HIV type 1 gag-specific T cell responses in Ad5 HIV Type 1 gag vaccinated human subjects.
abstract: Currently, there are numerous candidate HIV vaccines aimed at inducing T-cell mediated immune responses against HIV. To assess the immunogenicity of such vaccines, a reliable T cell assay must be utilized and typically one of the following assays is chosen for this purpose: bulk culture CTL, MHC I tetramer staining, IFN-gamma ELISPOT, or IFN-gamma intracellular cytokine staining. In this paper we report a comparison of the T cell responses detected by each assay in a large cohort of healthy normal volunteers vaccinated with adenovirus serotype 5 expressing HIV gag. Using stringently validated formats of each of these assays and pools of overlapping HIV gag peptides, we demonstrate that there is a high degree of correlation between all four of the common T cell assays, but inherent differences in the sensitivity of each assay to detect responders. In this study, the ELISPOT assay is shown to have the greatest sensitivity in detecting vaccine responses, while the ICS assay, although less sensitive, has the advantage of providing additional information on the phenotype of the responding cells.
authors.affiliation: Department of Vaccines and Biologics Research, Merck Research Laboratories, West Point, Pennsylvania 19486, USA. timothy_tobery@merck.com
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Tobery
authors.forename: Sheri A
authors.initials: SA
authors.lastname: Dubey
authors.forename: Kiersten
authors.initials: K
authors.lastname: Anderson
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Freed
authors.forename: Kara S
authors.initials: KS
authors.lastname: Cox
authors.forename: Jing
authors.initials: J
authors.lastname: Lin
authors.forename: Michael T
authors.initials: MT
authors.lastname: Prokop
authors.forename: Kara J
authors.initials: KJ
authors.lastname: Sykes
authors.forename: Robin
authors.initials: R
authors.lastname: Mogg
authors.forename: Devan V
authors.initials: DV
authors.lastname: Mehrotra
authors.forename: Tong-Ming
authors.initials: TM
authors.lastname: Fu
authors.forename: Danilo R
authors.initials: DR
authors.lastname: Casimiro
authors.forename: John W
authors.initials: JW
authors.lastname: Shiver
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology*; D000256:Adenoviridae; D000293:Adolescent; D000328:Adult; D005260:Female; D015683:Gene Products, gag / Q000276:immunology*; D015488:HIV Antigens / Q000276:immunology; D015658:HIV Infections / Q000517:prevention & control*; D015497:HIV-1; D006801:Humans; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D016915:AIDS Vaccines; D015683:Gene Products, gag; D015488:HIV Antigens