Researchers Determine Chemical Structure of HIV Capsid 90
adeelarshad82 writes "Researchers at the University of Illinois at Urbana-Champaign (UIUC) have determined the precise chemical structure of the HIV 'capsid,' a protein shell that protects the virus's genetic material and is a key to its virulence. The experiment involved mapping an incredible 64 million atoms to simulate the HIV capsid, pictured here. Interestingly no current HIV drugs target the HIV capsid and researchers believe that understanding the structure of the HIV capsid may hold the key to the development of new and more effective antiretroviral drugs. What makes this whole experiment even more fascinating is the use of Blue Waters, a Cray XK7 supercomputer with 3,000 Nvidia Tesla K20X GPU accelerators."
Re:The picture suggests ... (Score:5, Informative)
That there are numerous repeating elements in the capsid. Seems like this would be a perfect target for antibody formation. But obviously, that hasn't worked out. Be interesting to know why.
(Armchair biology is wonderfully simple, isn't it?)
The capsid is not exposed to the blood and therefore subject to interaction with antibodies. It's the layer beneath the viral capsule, and it is the capsule that is the most external layer which is exposed to the blood. Drug design will be likely to try and interact with the capsid once it is inside the cell and before it releases its payload
Mutations of the HIV virus (Score:4, Informative)
Interestingly no current HIV drugs target the HIV capsid and researchers believe that understanding the structure of the HIV capsid may hold the key to the development of new and more effective antiretroviral drugs
Since the "discovery" of the HIV virus in the late 1980's scientists have discovered that the HIV virus has undergone several mutations
Even if there are drugs which can successfully targets the HIV capsid that have been decoded in this experiment, it does not mean that the HIV virus won't mutate again, and change their capsid sequence (or chemical formula) to foil those drugs
But all in all, the effort in sequencing the capsid is indeed a breakthrough, a step forward in understanding the nature of the bug, even if it's one type, amongst the many varieties
Re:The picture suggests ... (Score:3, Informative)
The capsid doesn't enter the cell, but it is produced there.
There are many possible lines of defense against viruses. Ignoring natural innate/adaptive immunity, you can block viral binding to cells (target receptors). You can interfere with replication of viral genomes (reverse transcription inhibitors, a big one for HIV). You can prevent assembly of new viruses (capsid inhibitors: http://jvi.asm.org/content/82/20/10262.full [asm.org], note the way they used structure to guide their work). Or you can prevent viral capsid maturation (protease inhibitors, also big with HIV).
So while you can't target live (enveloped) virus with a capsid inhibitor (at least easily), you can prevent the formation of new virus. Here's a picture of what actually happens: http://jvi.asm.org/content/82/20/10262/F6.expansion.html [asm.org]. There should be nice tidy spheres of new capsids, and instead you get blobs of virally-useless junk.