Synthetic immunology, an innovative field of research which could lead to fundamentally new approaches and methods in the treatment of infectious diseases and cancer, is the topic of an article in the “Perspectives” section of the journal “Nature Nanotechnology”. Herein, Heidelberg researchers Prof. Dr. Kerstin Göpfrich, Prof. Dr. Michael Platten, Prof. Dr. Friedrich Frischknecht, and Prof. Dr. Oliver T. Fackler describe a so-called bottom-up approach that uses the toolbox of nanotechnology and synthetic biology to construct systems from molecular building blocks and specifically equip them with immune functions.