Reinvent Mesenchymal Stem Cells - A Synthetic Biology Approach to Engineer Programmable Cellular Theranostics

About This Grant

PROJECT ABSTRACT Mesenchymal stem/stromal cells (MSCs), the most abundant adult precursor cells in the human body, have been widely explored for various experimental and clinical applications and were recently approved for clinical use by the FDA. Nevertheless, a daunting challenge remains: the poor survival and reduced regenerative capability of MSCs in hostile microenvironments in the recipient tissue markedly undermine their efficacy and treatment outcome. Our proposal, “Reinvent Mesenchymal Stem Cells - A Synthetic Biology Approach to Engineer Programmable Adult Stem Cell Theranostics,” aims to overcome these limitations by engineering a programmable cellular theranostic platform for MSCs. We previously developed synthetic genetic circuits (SGCs) having upstream genetic sensors to detect intracellular signaling and downstream secretory effector molecules to program cellular signaling and desirable cellular functions under conditions of stress or disease. Here, we propose to integrate SGCs into MSCs to engineer Autonomous Impairment-inducible MSCs (aiMSCs). aiMSCs would spontaneously detect stress- or disease-induced intracellular signals via genetic sensors and initiate transgene expression to enhance cell survival and treat targeted pathologies. To ensure the safety and translational potential of aiMSCs, we will embed two types of autonomously programmable control mechanisms: 1) dual intracellular signaling feedback controls at the sensor and effector levels, and 2) a safety switch based on endogenous microRNA binding, to respond to the microenvironment in real time and increase effector output levels when the tissue damage intensifies or turn off the SGC when the tissue heals. As proof-of-concept, we propose two specific aims to develop the aiMSC technology and explore its potential as a next-generation MSC therapy. We will use synthetic biology, genetic engineering, and computational tools to engineer: 1) murine bone marrow (BM)-derived MSCs that automatically detect and respond to inflammatory signals, augment MSC survival, and promote a destructive-to-constructive transition in tissue inflammation (aiMSC-I); and 2) human BM-MSCs (hMSCs) that detect and respond to metabolic distress- induced signals and promote hMSC survival, anti-oxidation, and mitochondrial protection (HaiMSC-M). We will use cellular, organoid, and animal disease models to validate aiMSC-I and HaiMSC-M and to demonstrate enhanced MSC survival and functioning, as well as the self-contained and self-regulated modulation of disease conditions. Large-scale genetic sensor screening and machine learning will be used to identify unique MSC- specific pathology sensors. aiMSCs represent an adaptive, self-programmed theranostic approach that augments MSCs on demand in a safe and controlled manner. aiMSCs would significantly advance patient treatment and offer new perspectives for precision medicine, designer therapeutics, and stem cell therapies.