title: Enhanced rates and magnitude of immune responses detected against an HIV vaccine: effect of using an optimized process for isolating PBMC.
abstract: 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.
authors.affiliation: Vaccine and Biologics Research, Merck Research Laboratories, West Point and Wayne, PA 19087, USA. lisa_kierstead@merck.com
authors.forename: Lisa S
authors.initials: LS
authors.lastname: Kierstead
authors.forename: Sheri
authors.initials: S
authors.lastname: Dubey
authors.forename: Barbara
authors.initials: B
authors.lastname: Meyer
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Tobery
authors.forename: Robin
authors.initials: R
authors.lastname: Mogg
authors.forename: V Rose
authors.initials: VR
authors.lastname: Fernandez
authors.forename: Romnie
authors.initials: R
authors.lastname: Long
authors.forename: Liming
authors.initials: L
authors.lastname: Guan
authors.forename: Christine
authors.initials: C
authors.lastname: Gaunt
authors.forename: Kelly
authors.initials: K
authors.lastname: Collins
authors.forename: Kara J
authors.initials: KJ
authors.lastname: Sykes
authors.forename: Devan V
authors.initials: DV
authors.lastname: Mehrotra
authors.forename: Narendra
authors.initials: N
authors.lastname: Chirmule
authors.forename: John W
authors.initials: JW
authors.lastname: Shiver
authors.forename: Danilo R
authors.initials: DR
authors.lastname: Casimiro
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology* / Q000627:therapeutic use; D000256:Adenoviridae / Q000235:genetics; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D002986:Clinical Trials as Topic; D015925:Cryopreservation; D004797:Enzyme-Linked Immunosorbent Assay; D015658:HIV Infections / Q000517:prevention & control; D018023:HIV Seronegativity; D006801:Humans; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D013048:Specimen Handling; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors
chemical_list: D016915:AIDS Vaccines; D007371:Interferon-gamma