Single step enrichment of blood dendritic cells by positive immunoselection.
Dendritic cells (DC) for cancer immunotherapy protocols are generated most commonly by in vitro differentiation of monocytes with exogenous cytokines (Mo-DC). However, Mo-DC differ in their molecular phenotype and function from blood DC (BDC). Clinical isolation of BDC has been limited to the use of density gradients, which result in low yields of variable purity. We have developed a DC enrichment platform, which uses the CMRF-44 (IgM) or CMRF-56 (IgG) monoclonal antibodies (mAb) to select BDC that express these antigens after a short overnight incubation. After culture of peripheral blood mononuclear cells (PBMC) in autologous/AB serum, biotinylated CMRF-44 was used to select DC in a single step immuno-magnetic bead procedure; this produced populations containing up to 99% CMRF-44(+) cells, including up to 67% CMRF-44(+) CD14(-) CD19(-) DC, from an initial starting population of approximately 0.5%. We observed consistent differences in the purities obtained from individual donors with a mean of 54% CMRF-44(+) cells (range 19-99%). Similar results were obtained using biotinylated CMRF-56 mAb, an antibody identifying a comparable population in cultured PBMC. We recovered an average of 54% and 66% of the available BDC in separations performed with the CMRF-44 and CMRF-56 mAb, respectively. The reproducibility of the procedure and the ability to perform it in a closed sterile system makes it suitable for clinical use. Larger scale preparations starting from apheresis derived PBMC will produce sufficient BDC for immunotherapy protocols. The purified BDC elicited strong allogeneic mixed leukocyte reactions and HLA classes II- and I-restricted antigen-specific primary immune responses.
López
J Alejandro
JA
Mater Medical Research Institute, Aubigny Place, 4101, South Brisbane, Australia.
Bioley
Gilles
G
Turtle
Cameron J
CJ
Pinzón-Charry
Alberto
A
Ho
Chris S K
CS
Vuckovic
Slavica
S
Crosbie
Georgina
G
Gilleece
Maria
M
Jackson
David C
DC
Munster
David
D
Hart
Derek N J
DN
D000911:Antibodies, Monoclonal / Q000276:immunology; D000941:Antigens / Q000276:immunology / Q000378:metabolism; D000943:Antigens, Differentiation / Q000276:immunology; D002478:Cells, Cultured; D003470:Culture Media; D003713:Dendritic Cells / Q000145:classification / Q000276:immunology* / Q000637:transplantation; D015395:Histocompatibility Antigens Class I / Q000502:physiology; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods*; D016130:Immunophenotyping; D016219:Immunotherapy, Adoptive; D007700:Kinetics; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D009369:Neoplasms / Q000628:therapy; D013601:T-Lymphocytes / Q000276:immunology
D000911:Antibodies, Monoclonal; D000941:Antigens; D000943:Antigens, Differentiation; C119956:CMRF-56 antigen; D003470:Culture Media; D015395:Histocompatibility Antigens Class I