Controlling gene expression in mammalian cells constitutes one of the core principles of mammalian synthetic biology. Especially for cell-based therapies, inducers of gene expression which demonstrate the highest degree of safety and patient adherence are needed. In this chapter, I describe methods to implement caffeine-controlled gene expression systems into mammalian cells. Using an array of different implementation strategies, from reconstituting transcription factors to activating endogenous signaling pathways, allows for a wide range of sensitivity and capacity of the resulting caffeine-responsive gene switches.
Keywords: Caffeine; Inducible expression; Receptors; Synthetic biology; Transcription factors.