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Doctors Will Test Gene Editing On HIV Patients
Soychemist writes "Some people have a mutation that makes them highly resistant to HIV, and scientists think that they can give that immunity to anyone with a new type of gene therapy. The first human trials will start at the University of Pennsylvania this week. Researchers will draw blood from people with drug-resistant HIV, clip the CCR5 gene out of their T-cells with a nuclease enzyme, grow the modified cells in a dish, and then return 10 billion of them to the patient's bloodstream. Those cells will be immune to the virus, and they will keep the patient's T-cell count up even if the rest are destroyed. 'We will see if it is safe and if those cells inhibit HIV replication in vivo,' said the lead researcher. 'We know they do in the test tube.'"
What's the worst that could happen, they screw it up and you die?
While strides have been made in HIV treatment, it's still a death sentence. Doctors can keep the patient alive longer, but they can't prevent the inevitable.
With so many people in the developing world suffering from HIV, it would be nice to see something like this fast tracked. I am sure that some of those folks, now intimately familiar with their own mortality, would be eager to participate knowing that they could potentially help other people.
The HIV virus has a high rate of mutation, one of the reasons it sticks around in your body and your immune system has to keep attacking it, it's pretty much a "new" virus every time. What's to keep the virus from mutating and avoiding the CCR5 requirement it currently has? CCR5 doesn't seem to be a requirement for a normal human immune system (one of the many types of backups the immune system has), thus some percentage of the population being perfectly healthy without that receptor. I'd even go as far as to say that if HIV mutates into not requiring CCR5, then this new strain could spread and theoretically be worse than the current HIV strain in the wild.
HIV is a bastard of a virus. Our immune systems can usually handle most viruses without intervention. You cant win on your own against HIV. It will destroy the immune system eventually.
HIV is a bastard because it's relatively benign and very hard to transmit. A normal deadly virus like Ebola kills you quickly, HIV keeps you healthy and able to infect others for years. It's mainly transferred by sex, which is a big bummer for all of us who like to sleep around which includes lots of gay men.
But once you have it, you won't get rid of it. Nothing special either, because most people live with the chicken pox virus for most of their lives. That usually doesn't kill you, though...
X.
Instead of just making the typical /. armchair commentary about the zillion ways in which this proposal would be foolish or at best useless, I'm going to give a different angle on this.
First, on a global scale, the most sophisticated HIV treatments are administered to the relatively wealthy. Only when such a treatment is deemed effective does it start to spread down to the poor, due to economics. The old anti-retrovirals of yesterday are today's low-cost options for the millions of HIV+ individuals in developing nations. That's just the reality of the technological development of disease treatment. However, this "trickle-down" mechanism, combined with natural geographic and genetic variations, has led to the evolutionary branching of HIV into significantly distinct strains, with characteristically different disease modalities.
Second, we have as yet no drug that is able to eliminate HIV in the body. The currently available treatments are at best able to turn HIV into a chronic, managed condition. This has some very interesting (some would say alarming) socioeconomic implications. What we are finding is that over time, HAART therapy has evolved from a multiple-dose-per-day regimen that was difficult to maintain, to a more easily managed schedule, leading to better therapy adherence in patients. However, some of these drugs are poorly tolerated in many individuals, and over time, HIV is known to develop multiple resistances due to poor adherence or tolerance. The more disturbing situation, however, is that in many gay communities, the practice of "pre-exposure prophylaxis" has become alarmingly common. What is happening is that some HIV- gay men are obtaining anti-HIV drugs and taking them prior to knowingly exposing themselves to potentially HIV+ individuals through unprotected sex.
From a scientific standpoint, it is fascinating that this development is as successful as it has been. But from the standpoint of a gay man who takes every precaution to educate myself and follow safer sex practices and does everything in my power to serve as a role model for responsible behavior, I find it totally abhorrent that there are guys who expose themselves willingly to HIV in such an unethical manner, in light of all the AIDS deaths that have come before us and all the tireless work of our most brilliant scientists, medical care providers, and public health advocates. They have even given this "PrEP" cute names and euphemisms to disguise the utter insanity of what they are really doing (like they have done with the term "barebacking" to refer to unprotected anal intercourse). If there is anyone on the face of this earth that deserves to die of this terrible disease, it is them. And I don't say that lightly. Some of you might say that these people would have had unprotected sex with or without the drugs, but you have to realize that it is partly through the action of these individuals that drug-resistant HIV is spread. It is for this reason I dare stand in judgment against them.
So this brings me to my third point. The CCR5 discovery is notable in that it confers strong resistance against HIV-1. Two copies of the gene are required for this resistance. However, the transmission of other strains of HIV may not be blocked by the presence of this gene. Even if this therapy were to work, I doubt it would be effective on a large scale. Some of these patients, if you cure them, will simply go out and have more unprotected sex. If you don't believe me, reread the previous paragraph.
The only way human civilization will ever rid itself of the scourge of HIV is if we discover a vaccine or outright cure for all its strains. No chronic management or piecemeal therapy will be sufficient, because there are always people who will do things that will enable the virus to mutate and survive. Ever since the discovery and announcement of the virus in the 80s, this simple fact was apparent to me. But the untold billions of dollars in revenue that HIV research and managemen
I should add that this isn't a reason not to pursue research for cures for HIV. It's a very interesting problem and this technique may have broad application if it works. Also in some parts of the world HIV is very common and hard to avoid.
Just as we would treat a heart attack in a 400 lb man, so we should also treat someone with HIV as best we can.
I like my beverages with warning labels!
The problem being that many cell receptors that these viruses bind to (eg CAR coxaci adenovirus receptor) are highly conserved in humans. If we could just mutate the gene(s) that code for that receptor and nothing else happened it would be fine.
The reason that these genes and receptors are conserved is that they have essential functions, that may not yet be fully (if at all) understood.