While not delivering a knockout blow, the discovery of penicillin in 1928 provided a potent weapon in the fight against a wide range of bacterial infections. The quest to develop a similarly broad-spectrum drug to fight viral infections has proven more difficult but now researchers at MIT's Lincoln Laboratory have designed a drug that has so far proven effective against all 15 viruses it has been tested on. These include rhinoviruses that cause the common cold, H1N1 influenza, a stomach virus, a polio virus, dengue fever and several other types of hemorrhagic fever.
While there are a number drugs that are effective against specific viruses, such as the protease inhibitors used to control HIV infection, they are relatively rare and susceptible to viral resistance. In a development that could change the way viral infections are treated, the MIT researchers have designed a drug that can identify cells that have been infected not just by a specific virus, but by any virus, then kill those cells to terminate the infection.
When viruses infect a cell, they hijack its cellular machinery to create more copies of the virus, which then infect other cells, and so on. During this replication process, the viruses create long strings of double-stranded RNA (dsRNA), which isn't found in human or other animal cells. While human cells have proteins that latch onto dsRNA, which sets off a cascade of reactions that prevents the virus from replicating, many viruses are able to circumvent this by blocking one of the steps further down the cascade.
To get around this problem, Todd Rider, a senior staff scientist in Lincoln Laboratory's Chemical, Biological, and Nanoscale Technologies Group, had the idea of combining a dsRNA-binding protein with another protein that causes cells to undergo programmed cell suicide - a process called apoptosis.
The therapeutic agents devised by Rider are dubbed DRACOs (Double-stranded RNA Activated Caspase Oligomerizers). When one end of the DRACO binds to dsRNA, it signals the other end to initiate cell suicide. However, if it enters a cell and finds no dsRNA present, it leaves the cell unharmed. Because each DRACO also includes a "delivery tag," taken from naturally occurring proteins, it is able to cross cell membranes and enter any human or animal cell.
In addition to testing DRACO in human and animal cells cultured in the lab, the MIT team has also tested it in mice infected with the H1N1 influenza virus. Treated mice were completely cured of the infection and DRACO itself was shown to be not toxic to the mice. The team is now testing DRACO against more viruses in mice and reports promising results. Rider says he hopes to license the technology for trials in larger animals with his sights on eventual human clinical trials.
The MIT team's research appears in a paper published on July 27 in the journal PLoS One.
To destroy the Flu and Cold Virus, you have to do it through the nose, as the cells that line the respiratory tract are not basically bathed in the blood stream. Maybe now that is why Tamiflu is now doing there vaccines up the nose.
Imagine how big a dose that would take of a presumably extremely costly Rx? It\'s a lab curiosity at best and maybe a cure in small animals. Cost effective therapy requires highly specific drugs taken at low doses that target the diseased cells selectively without uptake by normal cells.
HR, Biotech consultant
But my biggest worry is this - this treatment employs the cell suicide trigger against the infected cell. What if viruses evolve to block all forms of cell suicide or even death... or aging, and we get the \"T-Virus\" from the Resident Evil games/movies that ends up turning us all into zombies? :-) :-) :-)
I didn\'t read anywhere in the article that the are making any such claim. If that was implied at all, it was implied by the author of the article.
You wrote: \"Imagine how big a dose that would take of a presumably extremely costly Rx?\"
Basically any size dose; the more the better as, so far, it has proven non-toxic. You seem to not understand completely what is meant by:
\"However, if it enters a cell and finds no dsRNA present, it leaves the cell unharmed.\"
When it leaves one cell, a DRACO is free to enter another, then another, then another, then another cell to repeat the process. Therefore, the size of the dose only determines how fast cells are examined; the more DRACOs within a given period of time, the faster the detection and eradication of infected cells.