Immunogenicity assay validation for an HIV vaccine trial: high IFNγ+/IL-2+ CD8+ T cells background in healthy Thais

Vaccine. 2011 Aug 11;29(35):6002-7. doi: 10.1016/j.vaccine.2011.06.035. Epub 2011 Jun 28.

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • AIDS Vaccines / immunology*
  • CD8-Positive T-Lymphocytes / immunology*
  • Clinical Trials, Phase I as Topic / methods*
  • Cytokines / metabolism*
  • HIV Infections / immunology*
  • HIV Infections / prevention & control
  • HIV Infections / virology
  • HIV-1 / immunology
  • Humans
  • Interferon-gamma / metabolism
  • Interleukin-2 / metabolism
  • Observer Variation
  • Reproducibility of Results
  • Staining and Labeling / methods
  • Staining and Labeling / standards*
  • Thailand

Substances

  • AIDS Vaccines
  • Cytokines
  • Interleukin-2
  • Interferon-gamma