Monocyte enrichment from leukapharesis products for the generation of DCs by plastic adherence, or by positive or negative selection.
BACKGROUND
DCs for use in immunotherapy are frequently generated from peripheral blood monocytes. However, there are different approaches to monocyte enrichment.


METHODS
Plastic adherence is a widely used method for the enrichment of monocytes collected in a leukapheresis procedure. Alternatively,monocytes may be enriched by positive selection using magnetic beads coupled to CD14 Abs, or by cell depletion using beads coupled to Abs against CD2 and CD19 to remove non-monocytes.


RESULTS
Positive selection resulted in the highest purity of immature DCs (97 +/- 1%), but in a low yield (8 +/- 3%). In contrast, depletion of non-monocytes gave a good yield (21 +/- 6%), but insufficient purity (42 +/- 10%). Conventional adherence procedures resulted in a good yield (25 +/- 5%) and reasonable purity (72 +/- 4%). All three monocyte enrichment procedures resulted in DCs that underwent maturation upon exposure to a combination of lipopolysaccharide and IFN-gamma. These DCs had a typical immune phenotype, they released similar amounts of IL-12, and had the capacity to support MLR.


CONCLUSIONS
Our data provide a basis to choose a monocyte enrichment procedure that favors high purity or a high yield. However, if a manual open system suffices, plastic adherence is a reasonable alternative.
Children's Cancer Research Institute, St. Anna Children's Hospital, Vienna, Austria.
T
T
Felzmann
V
V
Witt
D
D
Wimmer
G
G
Ressmann
D
D
Wagner
P
P
Paul
K
K
Hüttner
G
G
Fritsch
D000954:Antigens, Surface / Q000276:immunology; D019496:Cancer Vaccines / Q000138:chemical synthesis; D002448:Cell Adhesion / Q000276:immunology; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology / Q000637:transplantation*; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D007371:Interferon-gamma / Q000494:pharmacology; D018664:Interleukin-12 / Q000276:immunology / Q000378:metabolism; D007937:Leukapheresis / Q000379:methods*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008280:Magnetics; D009000:Monocytes / Q000166:cytology / Q000276:immunology / Q000637:transplantation*; D010969:Plastics; D033581:Stem Cell Transplantation / Q000379:methods*
D000954:Antigens, Surface; D019496:Cancer Vaccines; D008070:Lipopolysaccharides; D010969:Plastics; D018664:Interleukin-12; D007371:Interferon-gamma