Broad spectrum antibiotic drugs such as penicillin have saved countless lives via the eradication of bacterial infections. Unfortunately, we are still forced to suffer through the common cold each year because there are no “penicillins” in the fight against viruses. Most of the therapeutic anti-virals that do exist are highly specific. In other words, they usually target only a single type of virus or close relatives. A new approach from the Lincoln Laboratory at the Massachusetts Institute of Technology (MIT) called DRACO may revolutionize how viral infections are treated.
Todd Rider is the senior scientist at the MIT-based laboratory and leads the research with his colleagues on DRACO (Double-stranded RNA Activated Caspase Oligomerizer), which is a part of the PANACEA project (Pharmacological Augmentation of Nonspecific Anti-pathogen Cellular Enzymes and Activities). As opposed to vaccinations, which are based on training the immune system to recognize potential invaders by first being exposed to foreign bodies, DRACO would be administered as a drug to target existing infections. DRACO has a broad range of targets because it attacks any cells with more than 23 base pairs of double-stranded RNA. Almost all virus-infected cells produce double-stranded RNA that contain 30 or more base pairs. NewScientist.com explains that “the immune artillery within mammalian cells includes a protein that exploits this viral characteristic.” Normally, an enzyme called protein kinase R (PKR) triggers the cell’s defences when it discovers double-stranded RNA longer than 23 base pairs and production of the viral proteins is stopped. However, viruses are good at evolving and often find ways to get around these PKR defences.
Rider and his team altered PKR by attaching a kamikaze molecule that signals the cell to commit suicide when activated. The combination of the ability of PKR to sense foreign bodies and the destructive capabilities of the attached molecule forms DRACO — a drug that “catches the virus with its pants down,” according to Rider. The result is the annihilation of any infected cell before the virus can replicate in large numbers.
DRACO has successfully treated 15 types of viruses in tests involving both human and mouse cells according to NewScientist.com. Some of the viruses known to have succumbed to DRACO include those that cause dengue fever and polio, the adenoviruses, which are responsible for both the stomach flu and tonsillitis, and perhaps most excitingly for the average student, the rhinovirus that is responsible for some common colds in humans. Mice infected with the deadly H1N1 flu virus also had an increased survival rate when administered with DRACO. Rider believes the project’s potential is enormous, having the ability to prevent or treat even drug resistant HIV, Ebola and smallpox.
If DRACO sounds too good to be true, there may be good reason to question its capabilities. Andrea Branch of the Mount Sinai School of Medicine in New York points out some of the drawbacks of the anti-viral. She has commented that the DRACO protein is fairly large and therefore may have difficulty entering infected cells. She also questions how safe it would be for an individual with a lot of infected tissue, or even an entire organ that is infected, in which case she speculates that DRACO may in fact kill the patient.
As always, more research and further testing will need to be completed before we will know whether DRACO truly is the miracle drug it appears to be. But regardless of how the story turns out, there is no doubt that modern medicine is one step closer to a broad spectrum anti-viral breakthrough. And that, ladies and gentlemen, is excellent news.