Articles by Gabriel A. Kwong in JoVE
Nanosensors to Detect Protease Activity In Vivo for Noninvasive Diagnostics Brandon Alexander Holt1, Quoc D. Mac1, Gabriel A. Kwong1,2,3,4,5 1Wallace H. Coulter Department of Biomedical Engineering, Georgia Tech College of Engineering and Emory School of Medicine, 2Parker H. Petit Institute of Bioengineering and Bioscience, 3Institute for Electronics and Nanotechnology, Georgia Tech, 4Integrated Cancer Research Center, Georgia Tech, 5The Georgia Immunoengineering Consortium, Emory University and Georgia Tech Proteases are tightly regulated enzymes involved in fundamental biological processes, and dysregulated protease activity drives progression of complex diseases such as cancer. This method's goal is to create nanosensors that measure protease activity in vivo by producing a cleavage signal that is detectable from host urine and discriminates disease.
Other articles by Gabriel A. Kwong on PubMed
Individually Addressable and Dynamic DNA Gates for Multiplexed Cell Sorting Proceedings of the National Academy of Sciences of the United States of America. Apr, 2018 | Pubmed ID: 29632190 The ability to analyze and isolate cells based on the expression of specific surface markers has increased our understanding of cell biology and produced numerous applications for biomedicine. However, established cell-sorting platforms rely on labels that are limited in number due to biophysical constraints, such as overlapping emission spectra of fluorophores in FACS. Here, we establish a framework built on a system of orthogonal and extensible DNA gates for multiplexed cell sorting. These DNA gates label target cell populations by antibodies to allow magnetic bead isolation en masse and then selectively unlock by strand displacement to sort cells. We show that DNA gated sorting (DGS) is triggered to completion within minutes on the surface of cells and achieves target cell purity, viability, and yield equivalent to that of commercial magnetic sorting kits. We demonstrate multiplexed sorting of three distinct immune cell populations (CD8, CD4, and CD19) from mouse splenocytes to high purity and show that recovered CD8 T cells retain proliferative potential and target cell-killing activity. To broaden the utility of this platform, we implement a double positive sorting scheme using DNA gates on peptide-MHC tetramers to isolate antigen-specific CD8 T cells from mice infected with lymphocytic choriomeningitis virus (LCMV). DGS can potentially be expanded with fewer biophysical constraints to large families of DNA gates for applications that require analysis of complex cell populations, such as host immune responses to disease.