Transitioning from native to synthetic receptors: broadening T-cell engineering and beyond.

T-cell immunotherapy has progressed rapidly, evolving from native T-cell receptor biology to the development of innovative synthetic receptors that extend therapeutic applications beyond cancer. This review explores engineering strategies, ranging from natural TCRs to synthetic receptors, that increase T-cell activation and therapeutic potential. We begin by highlighting the foundational role of native receptors in the T-cell response, emphasizing how these structural and functional insights inform the design of next-generation synthetic receptors. Comparisons between CAR and TCR-like synthetic receptors underscore their respective advantages in specificity, efficacy, and safety, as well as potential areas for further improvement. In addition, gene editing technologies such as CRISPR-Cas9 enable precise modifications to the T-cell genome, enhancing receptor performance and minimizing immunogenic risks. In addition to tumors, these engineered T cells can be directed against viral infections, autoimmune disorders, and other diseases. We also explore advanced strategies that engage multiple immune cell types to achieve synergistic, durable responses. By demonstrating how native and synthetic receptors collectively drive innovation, this review aims to inspire new research directions and ultimately expand the scope of T-cell engineering for universal therapeutic applications.