BioE Seminar Series: Programmable RNA Sensing for Cell Monitoring and Editing

RNAs are the central and universal mediator of genetic information underlying the diversity of cell types and cell states, which together shape tissue organization and organismal function across species and life spans. Despite advances in RNA sequencing and massive accumulation of transcriptome datasets across life sciences, the dearth of technologies that leverage RNAs to observe and manipulate cell types remains a prohibitive bottleneck in biology and medicine. Here, we describe CellREADR (Cell access through RNA sensing by Endogenous ADAR), a programmable RNA sensing technology that leverages RNA editing mediated by ADAR (adenosine deaminase acting on RNA) for coupling the detection of cell-defining RNAs with translation of effector proteins. We have designed and implemented CellREADR in human cell lines and extensively characterized its RNA sensor and effector properties. We demonstrated that AAV-mediated delivery of CellREADR conferred specific cell type access in mouse and rat brains, and in ex vivo human tissues from temporal cerebral cortex. Furthermore, CellREADR enabled calcium imaging and optogenetic control of neuron types in behaving mice and electrophysiological recording of neuron types in ex vivo human cortex. CellREADR thus highlights the potential for RNA-based monitoring and editing of animal cells in ways that are specific, versatile, easy, and generalizable across organ systems and species, with broad applications in biology, biotechnology, and programmable RNA medicine. The latest progress will be presented.