Quantitative control of intracellular signaling activity through chimeric receptors incorporating multiple identical tyrosine motifs

Programmable synthetic receptors: the next-generation of cell and gene therapies

Cell and gene therapies hold tremendous promise for treating a range of difficult-to-treat diseases. However, concerns over the safety and efficacy require to be further addressed in order to realize their full potential. Synthetic receptors, a synthetic biology tool that can precisely control the function of therapeutic cells and genetic modules, have been rapidly developed and applied as a powerful solution. Delicately designed and engineered, they can be applied to finetune the therapeutic activities, i.e., to regulate production of dosed, bioactive payloads by sensing and processing user-defined signals or biomarkers. This review provides an overview of diverse synthetic receptor systems being used to reprogram therapeutic cells and their wide applications in biomedical research. With a special focus on four synthetic receptor systems at the forefront, including chimeric antigen receptors (CARs) and synthetic Notch (synNotch) receptors, we address the generalized strategies to design, construct and improve synthetic receptors. Meanwhile, we also highlight the expanding landscape of therapeutic applications of the synthetic receptor systems as well as current challenges in their clinical translation.

Rational design of heterodimeric receptors capable of activating target signaling molecules

Intracellular signal transduction is regulated by a variety of transmembrane receptors. Many researchers have aimed to arbitrarily regulate the intracellular signaling and subsequent cell fate with artificial receptors, of which the ligand recognition and signaling properties could be artificially designed. Although several architectures of homodimeric artificial receptors have been reported, engineering of heterodimeric receptors, which are abundant among natural receptors, have yet to be thoroughly investigated. In this study, we rationally design artificial heterodimeric receptors for activating target signaling molecules. We locate a tyrosine motif on an engineered tyrosine kinase domain, which is further connected to a small molecule-responsive heterodimeric module, attaining a pair of heterodimeric receptors with different tyrosine motifs within the pair. The resultant heterodimeric receptors successfully activate target signaling molecules and even control cell proliferation levels according to the properties of tyrosine motifs connected. Thus, our heterodimeric receptors may open a new era of tailor-made designer receptors, which could be useful for cell therapy against intractable diseases.

Biomolecular engineering for nanobio/bionanotechnology

Biomolecular engineering can be used to purposefully manipulate biomolecules, such as peptides, proteins, nucleic acids and lipids, within the framework of the relations among their structures, functions and properties, as well as their applicability to such areas as developing novel biomaterials, biosensing, bioimaging, and clinical diagnostics and therapeutics. Nanotechnology can also be used to design and tune the sizes, shapes, properties and functionality of nanomaterials. As such, there are considerable overlaps between nanotechnology and biomolecular engineering, in that both are concerned with the structure and behavior of materials on the nanometer scale or smaller. Therefore, in combination with nanotechnology, biomolecular engineering is expected to open up new fields of nanobio/bionanotechnology and to contribute to the development of novel nanobiomaterials, nanobiodevices and nanobiosystems. This review highlights recent studies using engineered biological molecules (e.g., oligonucleotides, peptides, proteins, enzymes, polysaccharides, lipids, biological cofactors and ligands) combined with functional nanomaterials in nanobio/bionanotechnology applications, including therapeutics, diagnostics, biosensing, bioanalysis and biocatalysts. Furthermore, this review focuses on five areas of recent advances in biomolecular engineering: (a) nucleic acid engineering, (b) gene engineering, (c) protein engineering, (d) chemical and enzymatic conjugation technologies, and (e) linker engineering. Precisely engineered nanobiomaterials, nanobiodevices and nanobiosystems are anticipated to emerge as next-generation platforms for bioelectronics, biosensors, biocatalysts, molecular imaging modalities, biological actuators, and biomedical applications.