Enhanced rates and magnitude of immune responses detected against an HIV vaccine: effect of using an optimized process for isolating PBMC.
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.
Kierstead
Lisa S
LS
Vaccine and Biologics Research, Merck Research Laboratories, West Point and Wayne, PA 19087, USA. lisa_kierstead@merck.com
Dubey
Sheri
S
Meyer
Barbara
B
Tobery
Timothy W
TW
Mogg
Robin
R
Fernandez
V Rose
VR
Long
Romnie
R
Guan
Liming
L
Gaunt
Christine
C
Collins
Kelly
K
Sykes
Kara J
KJ
Mehrotra
Devan V
DV
Chirmule
Narendra
N
Shiver
John W
JW
Casimiro
Danilo R
DR
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
D016915:AIDS Vaccines; D007371:Interferon-gamma