Function of Fresh and Cryopreserved Monocytes Assessed by Release of 51-CR Radioactivity from Human Red Blood Cells Coated With Antibody

摘要

Human peripheral blood mononuclear cells isolated from plateletpheresis were cryopreserved at -80 C with 10% DMSO for as long as 2.5 years. Monocyte functional activity was assessed before and after cryopreservation by the release of radioactivity during incubation with 51-Cr labeled red blood cells. The adherent population of monouclear cells was isolated to increase the proportion of monocytes in the mononuclear cell samples before testing for functional activity. In the first series of experiments, the functional activity of the monocytes appeared to be maintained during cryopreservation: the functional activity was 40% in the fresh samples and 45% following cryopreservation. However, the fresh samples were not assayed along with the cryopreserved samples, and there was a high degree of variability associated with the assay. In the second series of experiments, the cryopreserved mononuclear cells were assayed along with the fresh samples. The 22% functional activity observed in the cryopreserved samples was significantly lower than the 32% functional activity observed in the fresh samples. However, there was no correlation between the length of frozen storage and the functional activity. In vitro viability was assessed by testing membrane integrity using fluorescein diacetate and ethidium bromide and showed that the viability of the cryopreserved mononuclear cells was maintained at 90%. Human peripheral blood mononuclear cells can be cryopreserved at -80 C for as long as 2.5 years with only a slight loss of functional activity and in vitro viability.