The emergence of immunotherapy, including immune checkpoint blockade (ICB) and the adoptive transfer of cytotoxic lymphocytes, such as CAR-T cell therapy, has revolutionized cancer treatment. However, these therapies still face significant challenges in terms of both safety and efficacy. In this Ph.D. thesis, I developed several protein and receptor engineering strategies to enhance the safety and efficacy of cytokine-based therapies and CAR-T cell therapy against solid tumours.
In the first part of the dissertation, I designed and developed both OFF-switch and ON-switch systems to control therapeutic activity by using chemically-responsive domains. In one example, I engineered cytokines activity by selectively masking the receptor binding site with a fused chemically-responsive domain, which is released upon addition of a trigger molecule. I successfully identified switchable mutants for three different cytokines, including IL-2, IL-10, and IL-15, demonstrating significant drug-controllability in mouse models.
In the second part of the thesis, I focused on enhancing the efficacy of CAR-T cell therapies by modulating their biomechanical properties. To enhance the cytotoxicity of CAR-T cells through modulation immune synapse strength, I designed a new type of CAR by fusing the actin-binding domain of integrins with the cytoplasmic tail of a second-generation CAR. These mechanically strengthened CAR-T cells formed highly stable immune synapse with target cells and exhibited improved cytotoxicity in vitro and in vivo.