A programmable protease-based protein secretion platform for therapeutic applications.
                            
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                                BphS
                            
                                CRY2/CIB1
                            
                                Magnets
                            
                                PhyA/FHY1
                            
                            
                                
                                    Hana3A
                                
                            
                                
                                    HEK293T
                                
                            
                                
                                    hMSCs
                                
                            
                                
                                    mouse IPSCs
                                
                            
                            
                                Control of intracellular / vesicular transport
                            
                            
                            
                            
                            
                        
                        
                        
                        
                            Abstract:
                            Cell-based therapies represent potent enabling technologies in biomedical science. However, current genetic control systems for engineered-cell therapies are predominantly based on the transcription or translation of therapeutic outputs. Here we report a protease-based rapid protein secretion system (PASS) that regulates the secretion of pretranslated proteins retained in the endoplasmic reticulum (ER) owing to an ER-retrieval signal. Upon cleavage by inducible proteases, these proteins are secreted. Three PASS variants (chemPASS, antigenPASS and optoPASS) are developed. With chemPASS, we demonstrate the reversal of hyperglycemia in diabetic mice within minutes via drug-induced insulin secretion. AntigenPASS-equipped cells recognize the tumor antigen and secrete granzyme B and perforin, inducing targeted cell apoptosis. Finally, results from mouse models of diabetes, hypertension and inflammatory pain demonstrate light-induced, optoPASS-mediated therapeutic peptide secretion within minutes, conferring anticipated therapeutic benefits. PASS is a flexible platform for rapid delivery of therapeutic proteins that can facilitate the development and adoption of cell-based precision therapies.