(634a) Real-Time Modeling of the Growth and Phenotype of a Cytotoxic T Cell Line for Culture in a Novel Centrifugal Bioreactor with Applications in Immunotherapy

Cancer is one of the most significant issues facing modern medicine. It remains a leading cause of death and a cure has yet to be found. New immunotherapies, or treatments that utilize and enhance a patient’s immune system, have been introduced which have the potential to revolutionize treatment outcomes, but they have been restricted by manufacturing bottlenecks. The development of reliable immunotherapy is critical to provide an alternative to traditional chemotherapy and radiation treatments, which have many negative health effects. Implementation of immunotherapy requires a bioreactor that can rapidly expand modified T cells to fight a patient’s cancer. Systems currently in use for T cell manufacturing are costly and involve many complex steps to ensure that enough cells are expanded. Additionally, the cells themselves are very sensitive to metabolic changes in their surrounding environment, which if not properly controlled, can result in cell dysfunction and even the loss of their killing ability, in a process known as exhaustion. Our group has provided a solution to address these issues, a centrifugal bioreactor (CBR) that uses a balance of centrifugal and fluid forces in a conical chamber to reach and maintain high T cell densities. Our newest prototype, shown in the attached figure, can expand up to 1 x 10⁸ T cells over 5 days. More recent work in our group has focused on developing a model cell line that can be used to optimize the performance of our CBR prototype. We developed a line of bovine CD8+ cytotoxic T cells via stimulation with the parasite T. parva, which causes an immune response similar to that of cancers. We will report on efforts to assess the killing ability and effector activity of our model cell line, and to determine the effects, of changes in major CBR culture conditions and operating parameters on the resulting phenotype of T cells expanded in the system. We hypothesize that regulation of glucose and oxygen levels in the CBR will impact cell phenotype and will model this mathematically. We report on the results of flow cytometry assays used to evaluate phenotypic changes, the design of new mathematical models that predict the concentration of cells with a modified phenotype affected by glucose and oxygen concentrations in our system, and the implementation of glucose and oxygen sensors in our CBR that we can use to control cell culture conditions in real time. This research is expected to provide a streamlined T-cell manufacturing system that can efficiently culture and monitor large numbers of T cells for immunotherapy treatments, leading to groundbreaking advances in the efficiency and availability of life-saving cancer therapies.