Application of Logic Gate Regulated Constitutively Activated STAT Molecule for CAR T Cell Efficacy Improvement

Abstract

Cancer is a complex disease, therefore the treatment methods used to address it should be robust enough to effectively combat it. Despite their general success, standard methods of treatment such as chemotherapy or radiation are not suitable for many patients, children in particular, as the associated side effects can be extremely detrimental. Chimeric antigen receptor (CAR) T cell therapy is a solution, as it has shown great promise in combating cancer while overcoming the non-specific nature of traditional therapy methods and minimizing side effects. CAR T cell therapy involves isolating T-cells from a patient's blood and introducing recombinant DNA into them, which encodes for the CAR and other various transgenes that provide functional advantages. Despite the success that has been seen with CAR T cell therapy, there still however remains room for improvement. Studies have shown evidence of low T cell persistence, represented by poor cell expansion and tumor infiltration, thus resulting in the therapeutic effect declining over time. This project works to overcome these issues by implementing logic gate regulation of transgenes in a T cell-based therapy method. Various combinations of an inducible synthetic promoter and drug regulation will be explored to control expression of constitutively activated signal transducer and activator of transcription (caSTAT) molecules, which are transcription factors associated with cell survival. The synthetic promoter requires CAR activation for expression of the downstream caSTAT molecule. Fusion of estrogen binding domains (EBDs) to the molecules regulates their activity, based on the presence of an estrogen analog. These regulated systems are designed to achieve time and location control of transgene expression to minimize its side effects. Efficacy of these systems will be explored by applying them in in vitro models. The results will better inform the development of more regulated, personalized and efficient CAR T cell therapy methods for treating cancer in patients.