What’s happening at UGA
The Terns laboratory is working to understand precisely how the CRISPR system works in the bacterium Streptococcus thermophilus, which the dairy industry commonly uses to make yogurt and cheese; and in the archaeon Pyrococcus furiosus, which aids in the production of numerous industrially important enzymes and chemicals.
In particular, “we’re trying to utilize this system in good bacteria that we exploit to make foods, pharmaceuticals, and biofuels,” said Michael Terns.
The Terns group is developing RNA as well as DNA targeting systems and have used customized CRISPR RNAs to successfully disrupt expression of a protein responsible for resistance to commonly prescribed antibiotics such as penicillin and amoxicillin. This discovery could help bolster treatments that, because of overuse and misuse, have become largely useless against infection-causing bacteria.
In another set of experiments, led by Rick Tarleton, UGA Athletic Association Distinguished Research Professor of Biological Sciences, scientists are using CRISPR technology to speed the development of vaccines, diagnostics and treatments against Trypanosoma cruzi, an insect-borne parasite that causes Chagas disease. Known to result in irreparable damage to tissues of the heart and digestive systems, Chagas disease is the world’s single most common cause of congestive heart failure and sudden death.
Tarleton and his colleagues are using CRISPR to edit the genome of T. cruzi so that they may better understand how it interacts with host cells. This could ultimately help them identify potential weak points in the parasite’s life cycle, which researchers would then aim to exploit.
“Development of CRISPR in T. cruzi has totally changed what we can do, and even think of doing,” said Tarleton, who is also a member of UGA’s Center for Tropical and Emerging Global Diseases. “Manipulations that used to take us months, we can now complete in days, and experiments we have dreamed of performing for over 15 years are now doable.”
Similarly, Boris Striepen, a Distinguished Research Professor of Cellular Biology, is using CRISPR to genetically modify cryptosporidium, a microscopic parasite that causes the gastrointestinal disease cryptosporidiosis.
Crypto, as researchers often call the microorganism, is most commonly spread through tainted drinking or recreational water. When a person ingests contaminated water, parasites emerge from spores and invade the lining of the small intestine, causing severe diarrhea.
“One of the biggest obstacles with crypto is that it is very difficult to study in the lab, and that has made scientists and funders shy away from studying the parasite,” said Striepen. As a result, there is currently no vaccine and only one crypto-fighting drug—nitazoxanide—approved by the U.S. Food and Drug Administration.
But Striepen and his colleagues are looking to devise a new weapon for that battle. By deploying CRISPR to knock out specific genes in the cryptosporidium parasite, they can test the genes’ importance for the parasite and assess their potential value as a drug target.
Proceed with enthusiasm—and caution
The speed with which CRISPR is developing, combined with its potentially wide range of applications, has spurred both excitement and concern: excitement that it may well signal a revolutionary technology that could change the world for the better; concern about the possibility it could also result in harm.
For example, some worry that the technology could be used to alter the DNA of commercially important plants and animals before the effects of these manipulations on ecosystems are fully understood. And others are troubled that CRISPR might trigger social havoc in a rush to create so-called “designer babies”—offspring whose genetic characteristics are customized prior to their birth.
“Society faces this challenge when any powerful new technology emerges,” said Rebecca Terns. But she is optimistic that the scientific community will proceed with an abundance of caution and that the world will see substantial improvements in quality of life as a result of CRISPR technology—as long as we keep the big picture in mind and proceed carefully.
