Wednesday Colloquia

Next-generation targeting has organelle-level precision

by Prof. Yamuna Krishnan (University of Chicago)

Wednesday, January 5, 2022 from to (Asia/Kolkata)
at AG-66 and via ZOOM webinar ( Zoom link: https://zoom.us/j/97963259354?pwd=ZFZsa2xqWGJSZW5pUjZPNkNqeGlEZz09 )
Meeting ID: 979 6325 9354 Pass code: 04072020
Description
Intracellular organelles are relatively autonomous sub-systems within the cell, whose activity and chemical composition reflect the cell’s metabolic state.  Metabolism is altered in diseased or aging cells. This is reflected at the level of specific organelles within them. Often, introducing compensatory changes in organelles can restore cells to normalcy given the intrinsic feedback between cells and their organelles. Nature already targets the delivery of exogenous cargo with organelle-level precision in living organisms as evidenced by endogenous signaling molecules or pathogens such as viruses. Both signaling molecules and viruses are molecularly precise, nanoscale architectures. Like viruses, DNA too, can be self-assembled into molecularly precise, well-defined, synthetic assemblies on the nanoscale, commonly referred to as designer DNA nanodevices. Over the last decade, my lab developed a way to target DNA nanodevices to specific cells in vivo, but with organelle-level precision. Our first discovery in 2011 revealed that DNA nanodevices could reach organelles called lysosomes in specific cells of live nematodes, where it functioned as a reporter of pH. (1-2) Until this innovation, it was not at all obvious whether such DNA nanodevices could function inside a living cell without being interfered with, or interfering with, the cells own networks of DNA control. We spent 10 years studying the environment within lysosomes. Today I will discuss how we use the lysosome as a portal to control cell state in mice. We flip the state of the lysosome, make the lysosome flip the cell “from baddie to goodie” and in turn this make cold tumors hot. DNA nanodevices enable hyper-specific drug delivery.

References: 

1.	Modi, S., et al. A DNA nanomachine that maps spatial and temporal pH changes in living cells. Nat. Nanotechnol., 2009, 4, 325-330.
2. 	Surana, S., et al. An autonomous DNA nanomachine maps spatiotemporal pH changes in a multicellular living organism. Nat. Commun., 2011, 2, 340.
3. 	C. Cui et al A lysosome-targeted DNA nanodevice selectively targets macrophages to attenuate tumors Nat. Nanotechnol. 2021 16, 1394-1402.