1 Apr 2020
In this video, Dr. Maria Harkiolaki, Principal Beamline Scientist at Diamond Light Source, discusses the use of X-ray microscopy to track viral replication and infection in 3D and visualize the distribution of proteins within living cells. Here, Harkiolaki highlights how her lab is currently working to identify the mechanisms and mutations of several viruses, including the herpes virus and a member of the coronavirus family, with the hopes of aiding the development of new therapies. Harkiolaki also explores her role in designing and building user-friendly microscopes for other researchers who use the Diamond Light Source facilities.
I'm Maria Harkiolaki. I'm a Principal Beamline Scientist at the Biological Cryo-Imaging Beamline, at Diamond Light Source, which is the UK national synchrotron [inaudible]. My role is divided into two parts, really. I'm responsible for designing and building specific microscopes. In effect, we take X-rays of cells, and as part of that goal, I have to deliver this technology and make sure people, other scientists can use it.
At the same time, I have my own biology project, which involves specifically viral replication, and ultimately, understanding how a virus manages to successfully create progeny. Quite often, when we study a specific system, let's say a viral system, like the herpes virus, we'll focus on specific proteins. And although that will give us an idea of the interactions between viral proteins and the human immune system, for example, we really can't see what's happening inside a living cell.
With the microscopes we have at our Beamline, we can actually study and visualize the viruses in three dimensions inside living cells and actually track them as they infect. So, in that respect, we get a real understanding of how they distribute, and track macromolecules, like proteins, at the same time. In specific, in the herpes virus project, there's a process called secondary envelopment, where the virus attaches to cell membranes and it wraps itself around them while it's packaging.
In what we're doing specifically, we can see them while we're doing this, actually visualize the cell membranes and how they wrap around the virus. The idea is we can track specific mutations, and potentially, use them as drug targets later on. So once we understand how they form, and how they use the cell membranes, we could try to disrupt them.
My new project at the Beamline, we're starting quite soon, will be to look at the family member of the Coronaviruses. Now, this is not the human pathogen that is making the news right now, but any little bit of information we can gain from family members will contribute in a whole understanding of the evolution of this family of viruses, as well as how their protogenesis is in the infection process that moves along.
So any little information could be put into the pot to contribute to our whole understanding. So, what's quite special about what we do at our Beamline is we offer microscopes. We're using both X-rays and laser light, so effectively, we can pick a cell, and we freeze that cell so we get a snapshot.
We have arrested it at a specific point, and then we image it using X-rays. We image it using laser light and then combine the images to understand it better. Now, this is technology that doesn't exist anywhere else, at least for our kind of microscopy. Beyond that, it's not only an England method, it is available to the rest of the scientific community.
So our emphasis has always been make it user friendly. In thinking about the future, all of us that are working on models, and especially with infectious particles, what we're hoping to contribute is a piece of information that will join together with the work of other people, and in the end, we'll reach a space that we fully understand how a virus progresses through a cell. And that makes them ideal candidates for drug discovery. So hopefully, what we do here will feed into drug discovery at some point, maybe not in the near future, but certainly soon.
On the methodology side, the perfect microscope would be a microscope that has as much functionality as possible on the same sample, so I don't have to worry one cell is like another one. I know that it's the same one. And, very importantly, it's easy to use and it's user friendly. I believe we're heading in that way.
We have managed to capture at least three different microscopes in-house, but clearly there's more work to be done.
Diamond Light Source
Principal Beamline Scientist at Diamond Light Source