” Prior to our imaging technique, if one wanted to understand what was going on inside a cell, and to learn what modifications had actually taken place upon an infection, they d have to go through the procedure of repairing, slicing, and staining the cells in order to analyze them by electron microscopy. As part of a study released in Cell Reports Methods late last year, she and three colleagues carried out SXT on human lung cell samples prepared by their associates at Heidelberg University and the German Center for Infection Research.
“Nobody at Berkeley Lab, for example, is able to have those cells growing in their laboratory. If we were using transmission electron microscopy (TEM), for instance, it would have taken so much longer to track a single organelle like this,” since scientists utilizing TEM have to slice the cells, evaluate each particular slice individually, and then rebuild the location, she stated.
As part of his function at the German Center for Infection Research, Bartenschlager and his team have begun utilizing whole-cell SXT to take a look at how human cells respond to numerous speculative COVID-19-treating drugs.
Digital pictures of cells contaminated with SARS-CoV-2, developed from soft X-ray tomography taken of chemically fixed cells at the Advanced Light Source. Credit: Loconte et al./ Berkeley Lab
An exceptionally fast new 3D imaging technique can reveal how cells react to infection and to possible treatments.
To combat a pandemic, science needs to move quickly. With safe and effective vaccines now widely offered and a handful of promising COVID-19 treatments coming quickly, theres no doubt that numerous elements of biological research have actually been successfully sped up in the previous two years.
Now, researchers from Lawrence Berkeley National Laboratory (Berkeley Lab) and Heidelberg University in Germany have cranked up the speed of imaging infected cells using soft X-ray tomography, a tiny imaging method that can create exceptionally detailed, three-dimensional scans.
Their method takes mere minutes to collect information that would require weeks of prep and analysis with other methods, giving researchers a simple way to rapidly analyze how our cells internal machinery reacts to SARS-CoV-2, or other pathogens, along with how the cells respond to drugs created to treat the infection.
” Prior to our imaging method, if one wished to know what was going on inside a cell, and to discover what changes had occurred upon an infection, they d have to go through the procedure of repairing, slicing, and staining the cells in order to examine them by electron microscopy. With all the actions included, it would take weeks to get the answer. We can do it in a day,” stated job co-lead Carolyn Larabell, a Berkeley Lab faculty scientist in the Biosciences Area. “So, it actually speeds up the procedure of examining cells, the effects to infection, and the consequences of dealing with a patient with a drug that may or might not cure or avoid the disease.”
Taking cellular freeze frames
Larabell is a professor of anatomy at UC San Francisco and director of the National Center for X-Ray Tomography, a facility based at Berkeley Labs Advanced Light Source (ALS). As part of a study published in Cell Reports Methods late last year, she and three colleagues performed SXT on human lung cell samples prepared by their coworkers at Heidelberg University and the German Center for Infection Research.
Led by virologist Ralf Bartenschlager and physicist Venera Weinhardt, the German group thoroughly infected the cells with SARS-CoV-2 then chemically fixed them with aldehyde-based compounds– a process that kills cells and preserves them, paralyzed, in their last living state (and also inactivates any remaining viral particles)– at 6 and 24 hours post-infection.
Valentina Loconte and Jian-Hua Chen, mounting a brand-new cell sample on the X-ray microscopic lense at the National Center for X-Ray Tomography. Credit: Berkeley Lab
The entire team was pleased when the resulting 3D images had the same level of beautiful information and clarity that SXT is understood for, despite the chemical fixation done to the cells. The takeaway is that their method will permit lots of labs to safely image contaminated cells without the fundamental threats– and corresponding needed safety protocols– of working with live infected cells.
” This is an actually essential point because theres a great deal of hazardous organisms that people cant study since not everyone has a BSL-3 (Biosafety Level 3) laboratory,” Larabell described. “Nobody at Berkeley Lab, for instance, is able to have those cells growing in their lab. It opens up the doors to a lot of experiments on pathogens that we could not image before.”
Jian-Hua Chen and Valentina Loconte, scientists in Larabells group, carried out the tomography sessions and image analysis, respectively, at the National Center for X-Ray Tomography. Both were pleasantly surprised to see how SXT captured modifications to different organelles within the lung cells at really high resolution after very little time invested on sample preparation and without usage of stains or labeling. These extra actions are often needed to generate cell maps wherein the various internal elements are easily distinguishable.
” One information that struck me was the presence of this big membrane compartment that is probably the method the cell tries to recycle or get rid of all of the viral reproductive machineries,” stated Loconte, a postdoctoral scientist. She noted that the images showed the development of this strange compartment in nearly all the infected cells they studied. “It was highlighted truly clearly by our method. If we were using transmission electron microscopy (TEM), for circumstances, it would have taken so much longer to track a single organelle like this,” due to the fact that scientists utilizing TEM have to slice the cells, evaluate each particular piece individually, and then rebuild the location, she stated.
Spreading out the news
Now that theyve shown the potential of utilizing whole-cell SXT to safely image virus-infected cells, the authors believe that their findings will help the international clinical neighborhood research study COVID-19 and potentially other diseases.
As part of his function at the German Center for Infection Research, Bartenschlager and his group have actually begun utilizing whole-cell SXT to analyze how human cells react to numerous speculative COVID-19-treating drugs. They also plan to utilize the technology to comprehend the development of infections caused by other viral representatives.
” Being microscopists, we often state seeing is believing. Nevertheless, there are still a lot of unknowns for us to check out to get a much better understanding of the intricacies of virus-host interactions. This will require imaging large numbers of cells to obtain statistically significant details, provided the variations between contaminated cells that we observed,” stated Chen. “SXT provides the community a very great chance to investigate and observe what happens after human cells have been contaminated by infections. Im hoping this will open a window to respond to important concerns in the field of virology.”
Referral: “Using soft X-ray tomography for quick whole-cell quantitative imaging of SARS-CoV-2-infected cells” by Valentina Loconte, Jian-Hua Chen, Mirko Cortese, Axel Ekman, Mark A. Le Gros, Carolyn Larabell, Ralf Bartenschlager and Venera Weinhardt, 28 October 2021, Cell Reports Methods.DOI: 10.1016/ j.crmeth.2021.100117.
This work was supported by the German Research Foundation, the National Institute of General Medical Sciences of the National Institutes of Health, and the Department of Energy (DOE) Office of Science. The ALS is a DOE Office of Science user center.
