Integrated HIV Successfully Cut Out of Human Genome
Chris writes "German scientists have succeeded in snipping HIV out of human cells after it has integrated itself into a patient's DNA. The procedure is a breakthrough in bio-technology and fuels hope of a cure for AIDS. The group is only cautiously optimistic, though, as treating a full-on infection would be substantially different than succeeding in a controlled lab environment. 'Researchers ... began with the bacterial enzyme Cre recombinase, which exchanges any two pieces of DNA flanked on either end by a certain pattern of nucleotides (DNA subunits) known as loxP. HIV does not naturally contain loxP sites, so the team created a hybrid of the two DNA molecules, which they used to select a series of mutated Cre enzymes that were increasingly able to recognize the combined DNA. The final enzyme, Tre, removed all traces of HIV from cultured human cervical cells after about three months, the researchers report online today in Science.'"
I read about this in PhysOrg yesterday and they speak more about something the last paragraph of Scientific American only mentions. The fact that they wouldn't use this enzyme to remove HIV infections but instead to figure out which cells have been infected. The biggest problem in treating HIV is that it can go dormant and undetected for so long during which the host can infect others. It sounds horrible, but even being able to destroy all the cells infected with the virus is worth something though it may often prove fatal to the host. I don't think this is a 'cure' or 'vaccine' merely something that makes HIV treatments much much more effective.
My work here is dung.
HIV does not naturally contain loxP sites, so the team created a hybrid of the two DNA molecules, which they used to select a series of mutated Cre enzymes that were increasingly able to recognize the combined DNA.
So...this technique won't work at all in the real world. It won't even work with actual HIV even in the lab.
It's interesting research for its own sake, but in this case it has absolutely nothing to do with HIV. They simply found an interesting way to remove an arbitrary snippet of DNA. In fact, to make it work with HIV, they had to cheat and add tags to the HIV sequence.
This is like saying I could break into a bank vault after I replaced the lock with one I knew the combination to. It says nothing about the bank, only that I possess the capability to manipulate locks.
Think of this as an initial proof-of-concept. Fiddling with DNA is extremely useful - correcting genetic diseases and curing all sorts of viruses that hang out in your cells comes to mind (e.g. herpes). You could even look at curing cancer, since that's typically due to genetic mutations that could be potentially removed, making cells non-cancerous again.
Eventually, you'll want to be able to recognize and remove longer strands of DNA. I'd also worry about the efficiency - randomly removing strands of DNA from healthy cells is a good way to cause big problems. Existing gene therapies that use viruses to deliver the payload sometimes go astray and cause cancer, which is no good.
This is a big deal because it shows that this technique which has been used for years to cut out fragments of the genome for replication (via PCR and other methods) could be used to remove the viral elements from a genome. It's a big deal research-wise, but the major problem that will hinder this application from practical application is that HIV hybridizes EXTREMELY fast. Using an artificial bacterial enzyme to remove dna fragments requires a specific nucleotide sequence that it targets. Since HIV "changes appearance" (it actually mutates) at a super accelerated rate (100,000+ faster than animal genome) it makes treating (in this case removing) the virus very difficult. This is the same reason that current HIV treatments are effective at first, but slowly become less and less effective as the virus hybridizes. I'm not sure about needing a different enzyme for every strain of HIV, but that certainly makes sense. I don't claim to be an expert on this topic, but I certainly find it interesting. Just my 2 cents...
Could this lead to people getting away with murder because they can alter their DNA ?
Could this lead to people being framed for murder due to spoofed DNA ?
This sounds like it could destroy the credibility of DNA evidence for high-profile cases in the future.
Wanna fight ? Bend over, stick your head up your ass, and fight for air.
Do you, by any chance, wake up to public radio or similar? I find that sometimes the first 10 minutes or so of what is said on the radio, before I become fully cognizant, gets absorbed into my subconscious so that I think it is weird when I hear the same bit of news later in the day.
My eyes reflect the stars and a smile lights up my face.