LAUSR

20 Introduction DUOC-01 cells are a macrophage-like cell therapy product derived from umbilical cord blood that is currently being evaluated in a phase I clinical trial for patients with congenital lysosomal storage diseases (ClinicalTrials.gov Identifier: NCT02254863.) Manufacturing of DUOC-01 involves isolation of mononuclear cells from previously cryopreserved cord blood, plating on tissue culture flasks, and culturing for 21 days. Because of the strong adherent properties of these cells, scraping in addition to trypsinization is required during harvest, which decreases cell viability and is difficult to perform in a GMP environment. Objective The objective of this study was to find a harvest method that was gentler on the DUOC-01 cells and simplified the manufacturing process while maintaining cell function. Methods DUOC-01 cells were grown in either standard tissue culture flasks or Ultra Low Attachment Flasks (ULA, Corning Inc.) for 3 weeks. On day 21, different harvest methods were tested, including TrypLE, cold, PBS-EDTA, and longer incubation time. Cell surface markers were determined by flow cytometry. Activity was determined by intracranial injection of cells into murine model of cuprizone-mediated demyelination, then measuring remyelination in the corpus callosum 1 week later.