title: Immunogenicity assay validation for an HIV vaccine trial: high IFNγ+/IL-2+ CD8+ T cells background in healthy Thais.
abstract: In a vaccine trial, assays for vaccine immunogenicity if performed locally will strengthen local site, can save costs and avoid hurdles associated with specimen transport. Here we report the optimization and validation of an Intracellular Cytokine Staining (ICS) assay which was undertaken in preparation for a phase I HIV vaccine trial conducted in Thailand. Intra-, and inter-operator variability were easily established. However, while attempting to set population cut offs for a positive response we found 4/36 (11%) high background responses of IFNγ(+) and/or IL-2(+) CD8(+) T cells (>1%) in normal healthy volunteers. The determinates of these unexpected responses were explored and minimized.
authors: Faculty of Medicine, Chulalongkorn University, Rama IV Road, Pathumwan, Bangkok 10330, Thailand.
authors: Sunee
authors: S
authors: Sirivichayakul
authors: Pattarawat
authors: P
authors: Thantiworasit
authors: Pornsupa
authors: P
authors: Chatkulkawin
authors: Supranee
authors: S
authors: Buranapraditkun
authors: Mee Ling
authors: ML
authors: Munier
authors: Anthony D
authors: AD
authors: Kelleher
authors: Kiat
authors: K
authors: Ruxrungtham
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D017321:Clinical Trials, Phase I as Topic / Q000379:methods*; D016207:Cytokines / Q000378:metabolism*; D015658:HIV Infections / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D015497:HIV-1 / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D007376:Interleukin-2 / Q000378:metabolism; D015588:Observer Variation; D015203:Reproducibility of Results; D013194:Staining and Labeling / Q000379:methods / Q000592:standards*; D013785:Thailand
chemical_list: D016915:AIDS Vaccines; D016207:Cytokines; D007376:Interleukin-2; D007371:Interferon-gamma