Gene Surgery at Temple U

[geobee]

They can target HIV inside the cell.  It works in the test tube.  Seems a long way from the clinic, but still, it's pretty cool!

"Dr. Khalili along with his colleague, Wenhui Hu, MD, PhD, the Associate Professor of Neuroscience at Temple, led the groundbreaking research, which was funded by grants from the National Institutes of Health. Khalili and his team created molecular tools to delete the HIV-1 proviral DNA. They used a combination of DNA-snipping enzyme called a nuclease and a targeting strand of RNA called a guide RNA(gRNA) to hunt down the viral genome and excise the HIV-1 DNA. The process allowed the cell’s gene repair machinery to take over, soldering the loose ends of the genome back together leading to virus-free cells."

Here's the link:

http://www.nbcphiladelphia.com/news/local/Groundbreaking-Research-Could-Lead-to-Cure-for-AIDS-267860541.html

[freewillie99]

DNA-snipping enzyme called a nuclease

Sounds like a Zinc Finger nuclease.  Sangamo must be pleased.

[Almost2late]

Found a link this morning with the same story and came running to share it but Geo beat me to it.. Hope it leads to a cure somewhere down the road..

http://6abc.com/health/temple-univ-team-makes-breakthrough-in-hiv-aids-research/206012/

 

[Hoyland]

This research is not a zinc finger project. The team is using much newer technology called CRISPR, which stands for “clustered   regularly interspaced short palindromic   repeats". This technology still has a long way to go before we see it in the clinic but, if it can be delivered to the right cells, it has the potential to cut out any piece of DNA in the genome. As HIV is a retrovirus it places its DNA into the host genome so any tool that can cut out this viral DNA has the potential to be a permanent cure for the disease.

Of course, cutting the wrong section of DNA could have catastrophic effects and this is why there will be a lot of water to flow under the bridge before we see this in humans.

ZFN has been around for about 16 years. CRISP has been around for about 2 years.

[aaware72]

“It’s an important finding because for the first time in laboratory setting we show that the virus can be eradicated from human culture, cell culture, said Dr. Kamel Khalili, who led the research team. They developed molecular tools that can hunt down and delete HIV in cells. “Basically converting infected cells to un-infected cells and that is very important because the current therapy can not eliminate the virus from cells,” said Dr. Khalili."


http://philadelphia.cbslocal.com/2014/07/21/health-temple-university-researchers-successfully-eliminate-hiv-virus-in-human-cells/#.U83LJ_bOXDw.facebook

[zach]

i just want video of hiv virus dying, withering and painful death, screams of turture... maybe directed by rob zombie

that would freaking make my day

[tednlou2]

I just saw this on Facebook.  I kept wondering if the health reporter, Stephanie Stahl, is related to Leslie Stahl of "60 Minutes."  Of course, Leslie would have done a more in-depth look at the process.  But, good to see research is happening and researchers haven't given up, as illusive as it may be. 

[Miss Philicia]

There is already a thread on this: http://forums.poz.com/index.php?topic=54927.0

note: GO PHILLY!

[Jeff G]

Thanks Miss P !

[zach]

at some point i may well have to grudgingly admit that PHL must be a pretty cool place to be

[tryingtostay]

i just want video of hiv virus dying, withering and painful death, screams of turture... maybe directed by rob zombie

that would freaking make my day

you and me both

lol

[geobee]

Here's a more optimistic article:

http://guardianlv.com/2014/07/hiv-and-aids-eradication-may-be-possible-with-new-treatment/

"Khalili admits further work must to be done in order to make the technique suitable for testing on human subjects, however he is confident that the eradication of HIV and AIDS may be possible with this new treatment."

I sure hope that this CRISPR thing recognizes *only* HIV.  Wouldn't want this thing inside you cutting up the wrong genes accidentally.

[tryingtostay]

Here's a more optimistic article:

http://guardianlv.com/2014/07/hiv-and-aids-eradication-may-be-possible-with-new-treatment/

"Khalili admits further work must to be done in order to make the technique suitable for testing on human subjects, however he is confident that the eradication of HIV and AIDS may be possible with this new treatment."

I sure hope that this CRISPR thing recognizes *only* HIV.  Wouldn't want this thing inside you cutting up the wrong genes accidentally.

Yup.  I hope they would think of some kind of secondary fail safe method that would stop the thing from continuing.  Like something to mute or halt it if something goes wrong.  They should be developing that along side it's own creation.

[Reggie]

this is all good time being spent researching possibilities, hats off to those involved.

[Cosmicdancer]

This gives a little more detail on how CRISPR works.

"To make sure CRISPR-Cas9 hits its HIV target, the team coupled it with an appropriately named escort: guide RNA (gRNA). The gRNA attaches to a very specific section of DNA, which is found only in HIV, ensuring that CRISPR-Cas9 can’t miss. The team screened for accidental, “off-target” editing and found virtually none. At least in the laboratory, the drug homes to and inactivates viral genes while leaving host DNA unchanged. Perhaps best of all, healthy cells containing the Cas9/gRNA complex were also immune to HIV infection in the experiment."

Revolutionary Biotech May Offer HIV Cure

By David Shultz

Earlier this month, an HIV infection reemerged in a 4-year-old Mississippi girl believed to have been cured of the virus. Researchers thought that by administering antiviral drugs quickly after she was born, they could destroy the virus before it could insert itself into her DNA.

For four years, it seemed the treatment had worked, but on July 10th officials announced that they had detected levels of the virus in her blood. Her story is representative of one of the tragic difficulties in curing HIV: The virus can hide in host DNA for long periods of time, evading drugs and the immune system alike. But a powerful new protein, known as CRISPR-Cas9, now has HIV’s clandestine genes in its sights.

HIV is often depicted as a spherical, free-floating virus coated with spiky protein receptors. This is accurate, but it only represents part of the virus’ life cycle. Like only imagining frogs as tadpoles, our depictions of HIV often fail to tell the whole story. Much of HIV’s life is spent inside our cells, lying dormant amidst our DNA. The reason we so rarely see an image of this latent version of the virus is because, at this point in its life, it’s made of nothing more than DNA itself. There is no viral shell, or membrane, or spiky protein receptors—just the genetic instructions for making them, sort of like a sleeper terrorist cell waiting to be activated.

It’s estimated that, even when no HIV particles are detectable in the body, around ten million cells carry genetic copies of the virus. As a result, the symptoms can be treated, but the infection can’t be cured.

That all stands to change if Kamel Khalili has his way. He and his team at Temple University have directed a protein called CRISPR-Cas9 to sniff out and remove latent HIV genes. The experiment took place in myeloid cells growing in culture -- an apt model, as these nervous system cells have proven to be a particularly good reservoir for HIV. When applied, Cas9 acts like a pair of molecular scissors that cut both ends of the HIV DNA, slicing it out of our chromosomes and preventing it from being used to make more viruses.

“It’s extremely specific, very efficient, and surprisingly, it does what you anticipate it should do,” said Khalili with a laugh. “We’ve actually converted the cell lines which carried the virus to be virus-free cells.”   

One of the hardest parts of removing viral genes is finding them. The HIV-1 genome is 9,181 base pairs; our own contains around 3 billion. Finding those viral genes is tantamount to finding a fire ant on a mile-long stretch of highway. The cost of missing the mark can be dangerous too. Accidentally altering important, healthy genes can result in cancer or other harmful side effects.

To make sure CRISPR-Cas9 hits its HIV target, the team coupled it with an appropriately named escort: guide RNA (gRNA). The gRNA attaches to a very specific section of DNA, which is found only in HIV, ensuring that CRISPR-Cas9 can’t miss. The team screened for accidental, “off-target” editing and found virtually none. At least in the laboratory, the drug homes to and inactivates viral genes while leaving host DNA unchanged. Perhaps best of all, healthy cells containing the Cas9/gRNA complex were also immune to HIV infection in the experiment.

The power of the CRISPR-Cas9 system has been awe-inspiring since its potential as a gene-editing tool was realized in 2012. Now, it seems these proteins may be capable of removing HIV infection at its root.

There are, of course, large differences between curing HIV in the lab, and doing it in the body. “It has the potential, but it’s a tall order to get [CRISPR-Cas9] into every cell of the human body,” says Khalili.  “We should be able to develop a strategy to effectively deliver this technology to infected individuals, and we would hope that it does the same thing.”

If his team is able to do that, then they may very well cure HIV.

Source: Hu W et al. "RNA-directed gene editing specifically eradicates latent and prevents new HIV-1 infection." PNAS. Published online before print. doi: 10.1073/pnas.1405186111

http://www.realclearscience.com/articles/2014/07/23/revolutionary_biotech_may_offer_hiv_cure_108759.html

David Shultz is a freelance writer and an editorial intern at Nautilus Magazine. He tweets @dshultz14

[tryingtostay]

^ that's incredibly fascinating aside from the fact of my introspective look.

[geobee]

I agree.  Totally fascinating.  The idea of targeting a gene inside the body and changing it has huge implications for HIV and other genetic diseases.  It's mind-blowing.

[dico]

But Sangamo just did that 5 years ago albeit with ZFN technology and not Cas9.

The issue is how to deliver them inside all latently infected cells... With the actual knowledge it is impossible to do that. All we can is taking some blood cells out of the body, treat them and reinject them to the body.

You can see that we aren't going far with that.

[geobee]

This seems a little different than Sangamo in that their end goal is to modify the cells within the body instead of modifying your cells and then giving them back to you.   

[Reggie]

July 24, 2014

Scientists Devise Method of Snipping HIV From Immune Cells
Researchers have created a genetic treatment that, for the first time, has succeeded in removing HIV from infected human cells, providing hope that the technique may be used as part of a treatment, cure or vaccine for the virus. Publishing their findings in the Proceedings of the National Academy of Sciences, researchers devised molecular tools that delete HIV proviral DNA from infected cells.

When HIV infects a human cell, it integrates its DNA into the cell. The new technique takes what’s known as a “guide RNA,” or gRNA, which hunts down the virus’s genetic material, and pairs it with an enzyme called a nuclease that snips DNA out of the cell. The cell’s own methods of repairing genes then kick into gear, bringing the loose ends of the spliced genome back together. The result: a virus-free cell.

The process succeeded in removing the virus from various types of immune cells that HIV typically targets, including microglia, macrophages and CD4 cells.

To make sure the gRNA, which was built from 20 nucleotides (the basic building blocks of the genetic code), did not wind up integrated into the cell’s genome, the researchers constructed it from sequences that do not appear in the coding sequences of human DNA. This helped avoid any cell DNA damage and mitigated the risk of adverse effects.

“This is one important step on the path toward a permanent cure for [HIV],” study co-lead researcher Kamel Khalili, PhD, professor and chair of the department of neuroscience at Temple University in Philadelphia, said in a release.

The technique might be able to fight other viruses and could be used for an HIV vaccine, since cells that were protected by the combination of the nuclease and gRNA could not be infected.

“It’s an exciting discovery, but it’s not yet ready to go into the clinic. It’s a proof of concept that we’re moving in the right direction,” study co-lead researcher Wenhui Hu, MD, PhD, associate professor of neuroscience at Temple, said in the release.

A next step is to find a way to deliver the therapy to every infected cell. Also, because of HIV’s vast capacity to mutate, therapies may need to be tailored to a person’s particular viral gene sequences.

[tryingtostay]

Here is another link to the study.  Says the same thing basically but for those interested..

[tryingtostay]

What's the latest on this?  Or is there a page I can follow like a feed?