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Researchers Successfully Cut HIV DNA Out of Human Cells
mrspoonsi sends word that researchers from Temple University have managed to eliminate the HIV-1 virus from human cells for the first time. "When deployed, a combination of a DNA-snipping enzyme called a nuclease and a targeting strand of RNA called a guide RNA (gRNA) hunt down the viral genome and excise the HIV-1 DNA (abstract). From there, the cell's gene repair machinery takes over, soldering the loose ends of the genome back together – resulting in virus-free cells." While antiretroviral therapy can treat people who are infected with HIV, the immune system is incapable of actually removing the virus, so this is an important step in fighting it. The researchers still have to overcome the problem of delivering the the genetic "toolkit" to each affected cell in a patient's body, and also HIV's high mutation rate.
Why can't we quarantine these morons like we used to do with other diseases?
Because liberals are too nice to force people to spend the rest of their lives in isolation for getting some disease.
And because conservatives are too cheap to pay for it.
As demonstrated by our victory in the war on drugs, clearly we can just step up enforcement to solve the problem!
"The researchers still have to overcome the problem of delivering the the genetic "toolkit" to each affected cell in a patient's body"
Solution: Use the HIV virus itself
http://www.scripps.edu/news/press/2014/20140626torbett.html
"Viruses infect the body by inserting their own genetic material into human cells. In gene therapy, however, scientists have developed “gutted” viruses, such as the human immunodeficiency virus (HIV), to produce what are called “viral vectors.” Viral vectors carry therapeutic genes into cells without causing viral disease. Torbett and other scientists have shown that HIV vectors can deliver genes to blood stem cells."
The irony in this solution would be over 9000.
Here is probably the biggest difference in terms of a drug-development perspective: HIV relies on enzymes that are not normally found in the human body, so it is relatively easy to find drugs that can target these proteins without causing significant side effects. Cancer cells, however, are human cells themselves, so the proteins that drive tumor growth and malignancy are found in healthy cells as well. Thus, developing anti-cancer drugs is not just a matter of finding and inactivating the proteins that drive cancers, but also making sure that inactivating these targets does not harm other non-cancerous cells in the body.
http://www.pnas.org/content/early/2014/07/17/1405186111.abstract
This isn't such a big deal. Cas9/CRISPR is being used for all sorts of applications. This is just one of them, and the actual challenge isn't editing the genome, it is delivering Cas9/CRISPR to all cells of the body and having them being specific. That is far, far more difficult.
The authors detected INDELS (insertion/deletions) within the HIV-1 targetted sequence, so that is good -- it's doing what it should be in that respect.
However, Cas9/CRISPR can go OT (off target) and edit non-targetted DNA. It is the most specific editing tool that anybody has ever found, and will no doubt be Nobel-Prize worthy one day. But if OT effects happen, this is bad, when you start deleting/editing bits of DNA randomly - things can go wrong, cells and tissues can do things they're not meant to. Although that is fairly rare with Cas9/CRISPR -- however when exposed to megabases of DNA even rare events can become frequent (I would consider 1 OT effect too many for me, if I was about to be injected with something that was going to edit my Genome).
The authors did detect some OT effects (from their paper published in PNAS). So they carefully use the phrasing "minimize" OT effects in their paper. Also, they say "The long-term expression of Cas9/LTR-A/B gRNAs did not adversely affect cell growth or viability, suggesting a low occurrence of off-target interference with the host genome or Cas9-induced toxicity in this model." while it's a golf-clap worthy assay for cells in a dish (where's the rest of the assays for motility, cilial function, cell cycle length, etc.?), that isn't good enough either when uttering the words 'therapy'.
It's kind of neat, but I can see why this is PNAS and not Nature or Nat Med.