(293b) Development of a Novel Centrifugal Bioreactor with a Real-Time Monitoring Sensor for T Cell Exhaustion with Applications in Cancer Immunotherapy

It is impossible to downplay the critical challenges that the medical field is facing in the race to develop a reliable treatment for cancer. Over one hundred billion dollars are spent each year to treat the disease and a cure has yet to be discovered. Common cancer treatments such as radiation and chemotherapy can be effective in destroying cancerous tissue but cause many detrimental side effects. Thus, recent years have seen new treatment methods that specifically target cancers without damaging the rest of the body, such as immunotherapy. Adoptive cell therapy (ACT) is one form of immunotherapy in which patients’ immune cells are modified to target cancer cells and then reintroduced into the body. Widespread implementation of ACT has been a difficult task due to the high treatment cost and inefficient methods currently used to expand the cells. Additionally, if the production of cells is not carefully controlled, it can result in the cells losing their cancer-killing ability after expansion. In response to these concerns, our laboratory has designed a centrifugal bioreactor (CBR) for expansion of cytotoxic T cells for immunotherapy. The CBR uses a balance of centrifugal forces and fluid forces on the chamber containing the cells, as shown in the figure below, to quickly expand cytotoxic T-cells to high population densities. To validate the CBR, we recently began by optimizing the growth of CEM (human lymphoblastic leukemia) cells, which are similar to cytotoxic T lymphocytes (CTLs). We hypothesized that by designing a kinetic model from static culture experiments, we could predict the parameters necessary to achieve peak CEM and eventually CTL growth in the CBR. We will report on kinetic growth studies in which different glucose concentrations were tested with the CEM cell line in order to determine the maximum specific growth rate, as well as studies where varying levels of inhibitory growth byproducts were tested and critical inhibitor concentrations were determined. In this presentation, we will also report on results from another recent conceptual development in the design of the CBR: a fiber optic sensor that provides real-time monitoring and feedback control to regulate the cellular environment, based on levels of surface co-receptors and cellular mRNA regulation within the culture. Prior studies have pinpointed T cell exhaustion as a significant obstacle in achieving successful immunotherapy, particularly in treatments for solid tumors; T cell exhaustion occurs during a period of chronic antigen stimulation when the cells lose their ability to target and kill cancer cells, currently theorized to be associated with particular inhibitory receptors and cytokines in the immune system. The sensor we are developing will regulate the pathways involved in producing these receptors, which will ensure that the cells maintain cytotoxic properties during the expansion process within the CBR. In summary, achieving optimal kinetic models for the CBR system and methods to prevent T cell exhaustion have the potential to significantly enhance culture efficiency and availability of immunotherapy treatments.