Re: Why are retroviruses such an important area for inquiry and investigation t

Hi Sandy-

You ask a good question. Retroviruses are a really hot topic these days for a few different reasons. One reason for the hype is historical, while another one is technical, and one of the most important reasons deals with the public health problems they cause. I'll try to make sense of them for you!

First, I'll start with the grim stuff: some diseases retroviruses cause. First on most people's mind is HIV. Others include Walley dermal sarcoma virus,and Human spumavirus.
"But what is so special about retroviruses, other than that they cause disease?" you're probably asking. "Lots of things kill lots of people!"

Now we segue to the history. Throughout the early studies of cellular and molecular biology, people discovered DNA, RNA, and Proteins (not necessarily in that order). Soon, they realized that a general trend emerges: DNA allows for RNA to be made, and RNA allows for protein to be made. (a depiction and small description can be found at http://www.accessexcellence.com/AB/GG/central.html ). This concept was titled The Central Dogma. And being so titled, people were awfully dogmatic about it....

Then retroviruses were discovered. What was unique about retroviruses? They were able to make DNA from RNA - this is backwards from the central dogma; people were resistant to the idea at first. But the concept was indeed shown to be true.
Along with what part of the body the virus attacks, this aspect also makes the virus more dangerous. If it sticks its DNA into yours, it's possible that your cell could divide and make many, many more virus clones. Also, the virus stick this newly made DNA into your DNA anywhere it wants. If it happens to plop its payload right in the middle of a gene that keeps cells from dividing too quickly, it could also cause a tumor! A virus-producing tumor is not a good thing to have. However, this isn't that likely to happen. (just so you sleep at night)
In combating diseases like HIV, you often hear of anti-retroviral therapies - these treatments are trying to stop virus from making DNA.

Retrovirus are popular amongst the biotechnology circles because we want to harness the virus' capabilities to use a tool. Genetic diseases are tremendously common, and often the cause of the disease is one small mistake in the DNA. This mistake can prevent an important protein from being made, or it may cause the protein to work incorrectly. If we can add back the right piece of DNA, so the protein is made correctly, we could rescue the disease! This is pretty tricky, because we don't want people inhaling viruses. Viruses are pretty crafty, and can easily get around safeguards we try to put up. But the potential is there, and many people are looking into retroviruses as therapeutics. Also, the more we learn about retroviruses, the better we can treat people who have them.

I hope this provides some useful information for you, and sheds a little bit of light on why retroviruses are such the buzz these days. For more details, I'd leaf through some biology textbooks (preferably a cellular or molecular biology book - one of the classics is now on the web at http://www.web- books.com/MoBio/Default.htm .) Another website that is just chock full of details about retroviruses is http://www-micro.msb.le.ac.uk/335/Retroviruses.html.

-Alex Goddard
cgoddard@fas.harvard.edu