Engineering immune cells for next-generation therapies

Immune cell engineering has emerged as a transformative frontier in medicine, reshaping therapeutic strategies for cancer, autoimmunity and infectious diseases. Advances in delivery technologies such as viral vectors, lipid nanoparticles and polymer-based systems, together with precise gene editing tools including mRNA platforms and CRISPR, have enabled the efficient programming of immune cells with enhanced specificity and potency. Chimeric antigen receptor (CAR) designs exemplify how synthetic receptors can redirect immune recognition and function, and are now being applied not only to T cells but also to macrophages, natural killer cells and dendritic cells. These innovations are expanding therapeutic opportunities from hematologic malignancies to solid tumors and chronic inflammatory disorders. In parallel, the transition from ex vivo manipulation to in vivo reprogramming is beginning to address manufacturing bottlenecks and improve clinical accessibility. Moreover, artificial intelligence is increasingly driving rational design of vectors, CAR structures, and signaling networks for next-generation therapies. In this Review, we summarize current approaches to immune cell engineering, compare the characteristics of delivery systems and the design of engineered regulatory elements, and highlight therapeutic applications, while also discussing the outstanding challenges of safety, persistence and microenvironmental barriers that must be overcome to achieve durable and widely applicable therapies.