Chimeric antigen receptor (CAR)s are modular synthetic receptors that consist of four main components: an extracellular target antigen-binding domain, a hinge region, a transmembrane domain, and one or more intracellular signaling domains. Although the CAR-T with the co-stimulatory signaling domain such as CD28 or 4-1BB has received success in clinical studies, more and more research results revealed that the different combination of the four domains may have a synergistic effect to the CAR-T cells’ phenotype and functionality, which means the specificity, signal transduction, killing dynamics, proliferation, exhaustion, and in vivo survival of the T cells can be altered by editing any one of the four components, ultimately affecting the clinical efficacy and safety of the CAR-T cells. In the mean time, the 4th generation of CAR T cells have proven to be effective in multiple preclinical studies, which is one of the major methods in tackling the barriers of solid tumors.
Adopting the Design-Build-Test-Learning (DBTL) approach from the synthetic biology, and the directed evolution of molecules using single-cell characterization method, Immunofoco’s CAR-T cell screening platform systematically and efficiently generated a library of different combination of the domains, and a comparative analysis of their influence to the CAR-T cells’ performance. From there, Immunofoco assembled a display platform that empowers a rapid functional screening and optimization system, to filter from the numerous antigen binding or other functional domains and identify those candidate compositions that are ideal to the wanted characteristics. This platform accelerates the screening or optimization of CAR-T in solid tumors substantially.
