Recent advances in molecular mechanisms to improve the efficacy of CAR-T cell therapy for viral diseases, cancer, and autoimmune diseases.

Chimeric antigen receptor (CAR)-T cell therapy has transformed the treatment of hematological malignancies, yet its broader application to solid tumors, chronic viral infections, and autoimmune diseases remains constrained by antigen heterogeneity, immunosuppressive tissue microenvironments, T-cell exhaustion, limited persistence, and treatment-associated toxicities. These challenges have shifted the field from optimizing individual receptor constructs toward engineering CAR-T cells as programmable immune systems capable of adapting to diverse disease contexts. This review synthesizes recent advances in molecular engineering strategies that enhance CAR-T cell function beyond conventional receptor design. We discuss how receptor engineering, genome editing, transcriptional and epigenetic regulation, metabolic reprogramming, synthetic gene circuits, and safety-control platforms collectively reshape CAR-T cell fate, persistence, and therapeutic efficacy. Rather than functioning independently, these engineering strategies are increasingly integrated to generate context-specific cellular therapies capable of adapting to diverse disease environments, including cancer, autoimmune diseases, and chronic viral infections. We also highlight the potential for translation into clinical practice or clinical translation and discuss the major challenges associated with clinical implementation. Next-generation CAR-T therapies will increasingly integrate molecular engineering strategies or will rely on molecular engineering strategies to integrate antigen recognition, cellular fitness, immune regulation, and longevity rather than simply maximizing cytotoxic activity. Recent advances in programmable cellular engineering coupled with rigorous clinical evaluation as well as scalable manufacturing technologies or scalable manufacturing platforms in the treatment of other diseases beyond oncology will facilitate the development of safer, more durable, and broadly applicable cellular therapies.