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Biology subjects

Sin, W.-X.

Publications and source records attributed to Sin, W.-X..

3 recordsLinked to original sources

Dynamic estimation of metabolic state during CAR T cell production and the relationship of early metabolism to final therapeutic product

Adoptive cell therapies such as CAR T cells have revolutionized cancer treatment and shown successes even with refractory cases of haematological malignancies. There is burgeoning interest in the optimization and improved manufacturing of cell therapy products. For CAR T cell therapy, enrichment of certain phenotypes of T cells in the infusion product have been correlated with improved long-term treatment outcomes. While metabolic control of T cell phenotypic fates has been demonstrated in some contexts, gaps still exist in our knowledge of how T cell metabolic dynamics early during CAR T manufacturing might affect critical quality attributes (CQAs) of the final product (e.g., differentiation/exhaustion/potency). We present a modelling framework that can perform real-time estimation of per-cell metabolic rates of T cells expanded ex vivo in a reactor. We validate our estimated rates using metabolic assays, show how average rates can be deconvoluted to rates of individual T cell phenotypes, and demonstrate applicability to different reactor types. Applying our tool to the expansion of both healthy and patient-derived cells in a perfusion-based microbioreactor, we offer proof-of-principle to show that correlations exist between early metabolic rates of T cells in culture and cellular attributes related to growth, differentiation and exhaustion of the final product. Given the biological variation that exists in the growth and dynamics of patient-derived cells in culture, such modelling contributes to the overarching goal of improving the consistency of cell therapy through Adaptive Process Control (APC).

cancer biology↗

Use of cellular FAD autofluorescence as a label-free cellular attribute for the production of chimeric antigen receptor-T cells

Chimeric antigen receptor T (CAR-T) cell therapy has become an attractive approach for treating hematological malignancies. However, the accessibility of this therapy is limited by factors such as complex manufacturing process, limited capacity of manufacturing facilities and the requirement of highly skilled workforce for the manual steps of CAR-T cell production. To minimize the manual processes, CAR-T cell manufacturing field is shifting towards closed and automated systems, including analytical tools that offer intermittent monitoring of cells in production. Therefore, label-free technologies for closely monitoring CAR-T cells in closed systems are needed. Here, we evaluate the use of a flow cytometer equipped with a 405nm violet laser for investigating the NADH and FAD autofluorescence in T cells. Our results revealed the increase of NADH and FAD autofluorescence were significantly correlated with the upregulation of T cell activation marker, CD25 and the increase of extracellular lactate in spent media in the first three days after T cell activation. We demonstrate the potential use of FAD for determining the endpoint of CAR-T cell manufacture by establishing a relationship between the rate of change in the mean fluorescence intensity (MFI) of FAD in CAR-T cells and the rate of change in T cell proliferation using a G-Rex bioreactor. Collectively, these findings suggest that autofluorescence, particularly FAD autofluorescence, can serve as a label-free biomarker (cellular attribute) for monitoring T cell activation and expansion during CAR-T cell production. The use of 405nm visible light to substitute the genotoxic UV wavelengths for assessing the NADH and FAD autofluorescence, paves the way to incorporate autofluorescence measurements into closed and automated systems for in-process monitoring of CAR-T cell manufacturing.

immunology↗

High-density microbioreactor process designed for automated point-of-care manufacturing of CAR T cells

While adoptive cell therapies have revolutionized cancer immunotherapy, current autologous chimeric antigen receptor (CAR) T cell manufacturing face challenges in scaling to meet patient demands. CAR T cell production still largely rely on fed-batch, manual, open processes that lack environmental monitoring and control, whereas most perfusion-based, automated, closed-system bioreactors currently suffer from large footprints and working volumes, thus hindering process development and scaling-out. Here, we present a means of conducting anti-CD19 CAR T cell culture-on-a-chip. We show that T cells can be activated, transduced, and expanded to densities exceeding 150 million cells/mL in a two-milliliter perfusion-capable microfluidic bioreactor, thus enabling the production of CAR T cells at clinical dose levels in a small footprint. Key functional attributes such as exhaustion phenotype and cytolytic function were comparable to T cells generated in a gas-permeable well. The process intensification and online analytics offered by the microbioreactor could facilitate high-throughput process optimization studies, as well as enable efficient scale-out of cell therapy manufacturing, while providing insights into the growth and metabolic state of the CAR T cells during ex vivo culture.

bioengineering↗