title: Frozen-thawed human blood monocytes respond reproducibly to activation stimuli: implications for screening of BRMs.
abstract: The purpose of this study was to identify the optimal freezing conditions for human blood monocytes to allow their recovery and use for in vitro screening of activation stimuli. Human monocytes separated from buffy coats of healthy blood donors were suspended at a density of 1 x 10(7) cells/ml in freezing medium consisting of 70% medium: 20% fetal bovine serum: 10% DMSO frozen in a stepdown freezer, and stored at -180 degrees C. Monocytes were thawed at different times up to 4 months later. Viability was > 90%. Fresh monocytes from different donors and frozen monocytes thawed at different times were incubated with different concentrations of lipopolysaccharide, muramyl tripeptide, muramyl dipeptide, or lipopeptide. Tumoricidal activity and IL-1 production of fresh monocytes varied greatly among the 5 different preparations. In contrast, the frozen monocytes (thawed at different times) produced uniform levels of antitumor activity and IL-1 production. These results show that monocytes recovered from frozen storage maintain their ability to respond to activation stimuli in a uniform and reproducible manner. Thus, the use of frozen-thawed monocytes is recommended for screening of macrophage-activating agents.
authors.affiliation: Department of Cell Biology, University of Texas M.D. Anderson Cancer Center, Houston 77030.
authors.forename: T
authors.initials: T
authors.lastname: Utsugi
authors.forename: D
authors.initials: D
authors.lastname: Brown
authors.forename: A
authors.initials: A
authors.lastname: Nii
authors.forename: I J
authors.initials: IJ
authors.lastname: Fidler
mesh_terms: D015925:Cryopreservation; D004353:Drug Evaluation, Preclinical; D005615:Freezing; D006801:Humans; D007155:Immunologic Factors / Q000494:pharmacology*; D007375:Interleukin-1 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000494:pharmacology; D008262:Macrophage Activation / Q000187:drug effects; D008545:Melanoma / Q000628:therapy; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D016260:Monocytes, Activated Killer / Q000187:drug effects / Q000502:physiology; D015203:Reproducibility of Results; D014407:Tumor Cells, Cultured
chemical_list: D007155:Immunologic Factors; D007375:Interleukin-1; D008070:Lipopolysaccharides