Enhanced rates and magnitude of immune responses detected against an HIV vaccine: effect of using an optimized process for isolating PBMC

AIDS Res Hum Retroviruses. 2007 Jan;23(1):86-92. doi: 10.1089/aid.2006.0129.


Quantitative analysis of cell-mediated immune responses induced by candidate HIV vaccines requires robust procedures for collecting and processing human peripheral mononuclear blood cells (PBMCs). We evaluated several parameters in order to optimize a sample handling process that would be suitable for a multicenter clinical trial. Among the findings, systematic increases in the magnitude of IFN-gamma ELISpot responses were observed when the time from blood collection to PBMC freezing was reduced to <12 h. By implementing these improvements within an ongoing clinical trial, the estimated immunologic response rates to an adenovirus- based HIV vaccine increased by more than 20 percentage points to approximately 80% of the vaccine recipients against any of the vaccine antigens and the average levels of T cell response improved more than 3-fold. These studies establish the importance of optimal conditions for PBMC collection and handling to the success of a clinical development program.

Publication types

  • Comparative Study

MeSH terms

  • AIDS Vaccines / immunology*
  • AIDS Vaccines / therapeutic use
  • Adenoviridae / genetics
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Cells, Cultured
  • Clinical Trials as Topic
  • Cryopreservation
  • Enzyme-Linked Immunosorbent Assay
  • HIV Infections / prevention & control
  • HIV Seronegativity
  • Humans
  • Immunity, Cellular
  • Interferon-gamma / immunology
  • Leukocytes, Mononuclear / immunology*
  • Specimen Handling*
  • T-Lymphocytes / immunology
  • Time Factors


  • AIDS Vaccines
  • Interferon-gamma