Synthetic control of mammalian-cell motility by engineering chemotaxis to an orthogonal bioinert chemical signal

Abstract

Directed migration of diverse cell types plays a critical role in biological processes ranging from development and morphogenesis to immune response, wound healing, and regeneration. However, techniques to direct, manipulate, and study cell migration in vitro and in vivo in a specific and facile manner are currently limited. We conceived of a strategy to achieve direct control over cell migration to arbitrary user-defined locations, independent of native chemotaxis receptors. Here, we show that genetic modification of cells with an engineered G protein-coupled receptor allows us to redirect their migration to a bioinert drug-like small molecule, clozapine-Noxide (CNO). The engineered receptor and small-molecule ligand form an orthogonal pair: The receptor does not respond to native ligands, and the inert drug does not bind to native cells. CNOresponsive migration can be engineered into a variety of cell types, including neutrophils, T lymphocytes, keratinocytes, and endothelial cells. The engineered cells migrate up a gradient of the drug CNO and transmigrate through endothelial monolayers. Finally, we demonstrate that T lymphocytes modified with the engineered receptor can specifically migrate in vivo to CNO-releasing beads implanted in a live mouse. This technology provides a generalizable genetic tool to systematically perturb and control cell migration both in vitro and in vivo. In the future, this type of migration control could be a valuable module for engineering therapeutic cellular devices.GPCR | cellular therapeutics | synthetic biology

Using synthetic biology to explore principles of development

“…Modules have also now been constructed that 'rewire' morphogenetic events to respond to purely synthetic controls. An example is the system constructed by Park et al (2014), which confers on a variety of cells a chemotactic response towards the small molecule clozapine-N-oxide, which is inert to naturally evolved biological systems.…”

Engineering synthetic optogenetic networks for biomedical applications

“…Recently, a variety of microbial and plant-derived light-sensitive proteins have been engineered as optogenetic actuators to spatially and temporally control gene expression in various cells ( Figure 6). Using different types of opsins and viral delivery vectors for devising new optogenetic tools, investigators can engineer cells to detect and respond to a variety of extracellular and intracellular signals to manipulate the cellular machinery towards novel purposes with precise spatiotemporal control [91][92][93][94]. For example, designable transcription factors such as zinc fingers (ZF) and transcription-activator like effectors (TALE) can be engineered to bind any DNA segment of choice.…”

Synthetic biology in cellular immunotherapy

“…CD16 binds to antibodies, and choosing antibodies that bind to the surface of cancer cells will drive T cell activity against the cancer cell [51]. (C) Engineered receptor for chemotaxis [59]. RASSLs, an engineered G protein-coupled receptor, are activated at the surface of the T cell by a drug and drive chemotaxis of the cell along the drug gradient.…”