Designing natural and synthetic immune tissues.

Vaccines and immunotherapies have provided enormous improvements for public health, but there are fundamental disconnects between where most studies are performed-in cell culture and animal models-and the ultimate application in humans. Engineering immune tissues and organs, such as bone marrow, thymus, lymph nodes and spleen, could be instrumental in overcoming these hurdles. Fundamentally, designed immune tissues could serve as in vitro tools to more accurately study human immune function and disease, while immune tissues engineered for implantation as next-generation vaccines or immunotherapies could enable direct, on-demand control over generation and regulation of immune function. In this Review, we discuss recent interdisciplinary strategies that are merging materials science and immunology to create engineered immune tissues in vitro and in vivo. We also highlight the hurdles facing these approaches and the need for comparison to existing clinical options, relevant animal models, and other emerging technologies.