Researchers at Tel Aviv University have proved the CRISPR system can be used to precisely and reliably identify viruses and bacteria that infect crew members during space missions.
The experiment was conducted in the International Space Station, testing genetic diagnosis under microgravity conditions using the CRISPR system.
CRISPR systems are the immune systems of bacteria from viruses. Bacteria use the CRISPR-Cas systems as a sort of molecular “search engine” to locate viral sequences and cleave them in order to disable viruses.
The study was led by Dr. Dudu Burstein from the Shmunis School of Biomedicine and Cancer Research, Tel Aviv University and Dr. Gur Pines from the Volcani Institute.
The experiment was conducted in space by astronaut Eytan Stibbe as part of the “Rakia” mission launched to space in April, under the leadership of the Ramon Foundation and the Israel Space Agency.
Two scientists who studied (CRISPR), the sophisticated defense mechanism, Prof. Emmanuelle Charpentier and Prof. Jennifer Doudna, succeeded in redirecting it to perform gnome editing on various organisms, including the DNA of human cells.
Doudna and Charpentier earned international recognition when they were awarded the Nobel Prize in Chemistry in 2020. Dr. Burstein is a former member of the Doudna – he spent several years in her lab as a postdoctoral associate, learning about CRISPR-Cas from one of the greatest authorities in the field.
The CRISPR system was recently used to identify various organisms with extreme precision based on recognition of specific DNA sequences.
As part of their scientific vision, the researchers hypothesized that genetic diagnostics using this method, which requires minimal and easily operated equipment, could be suitable for long space missions, for example, at the International Space Station, or on future missions to explore the moon and Mars.
“Conditions in space are extremely problematic, and treatment methods are limited, so it is essential to identify pathogens in a rapid, reliable, and straightforward method,” Burstein explains.
“Tests like PCR, which we are now all familiar with, require trained personnel and relatively complex equipment. In the International Space Station, we tested a CRISPR-based detection method developed by Dr. Janice Chen and colleagues in the Doudna lab. First, the DNA is amplified: each targetted DNA molecule is repeatedly duplicated many times, and then the CRISPR-Cas goes into action: If it identifies the target DNA, it activates a fluorescent molecular marker i.
“The fluorescence lets us know whether the bacteria or viruses of interest are indeed present in the sample. This whole process can be conducted in one tiny test tube, so it can suit well the astronauts’ needs.”.
Doctoral student Dan Alon and Dr. Karin Mittelman planned the experiment in detail and conducted it countless times in the lab under various conditions. “After reaching the desired result, they prepared a kit, including the CRISPR-Cas system and the other components required for detection. Eventually, this kit was launched together with Eytan Stibbe to the International Space Station,” Burstein says.
The results of the experiments conducted by Stibbe were highly successful, and the researchers proved that it is indeed possible to perform precise and sensitive CRISPR-based diagnosis even in an environment with virtually no gravity.
“This is the first step towards the simple and rapid diagnosis of diseases and pathogens even on space missions,” Burstein says.
“There is still work to do on the next stages: simple extraction of DNA from samples, making the system more efficient, such that it will be able to test a variety of organisms in one test tube, and diagnosis of more complex samples. It was inspiring to see our test kit in Eytan’s hands at the Space Station, and we’re even more excited by the possibility that such kits will help future astronauts on their extraterrestrial missions.”