Slashdot Mirror
Gene Transfer Immunizes Against Monkey HIV Analog
Al writes "Researchers at the University of Pennsylvania have immunized monkeys against the simian immunodeficiency virus, the animal model that is closest to HIV. They did so by shuttling a gene into the monkeys' muscles, making the muscle cells produce antibody-like molecules that work against SIV. With both SIV and HIV, the chameleon-like mutability of the virus's surface changes so quickly that most antibodies made by the immune system are soon rendered ineffective. Philip Johnson and colleagues designed DNA sequences for two antibodies known to be effective against SIV. They used antibody-like molecules, called immunoadhesins, in which the functional part of an antibody is fused with a more stable section of another antibody. The same approach could be used to deliver antibodies that are effective against HIV, but which the body doesn't normally produce."
I'm kind of seeing this technique as an end-run around the "decoy" problem. It's been well known for some time that, at least in the general population, the antibody response against HIV tends to get targeted towards features which are non-protective or hyper-mutable.
However, over time we've come to discover a very small number of patients who have unusual resistance to progression. Some of these possess receptor mutations, some have unusual HLA types, while others were merely infected with what appeared to be somewhat milder variants of the virus.
However, in a few rare cases, we discovered patients with antibodies that were unusually effective at dealing with HIV's evasions. Often these antibodies had "weird" features -- things like floppy sections of their variable regions that allowed them to reach down to contact hidden epitopes, and other rare features. While they offered hope that an effective antibody response was not impossible, at the same time there really much chance of designing an antigen in such a way to get the general population to produce these unusual variants.
So, what this work has apparently done, is skip the entire vaccination step. Clone out the sequence for those particularly effective antibody variants, get your target organism to express them directly. However HIV may adapt to the new antibodies, as long as you can find one single person, somewhere in the world with an effective antibody response, it can be duplicated elsewhere.
Maybe, but at the same time if it works 80% of the time, then the infection rate will go down much further than that and stop the problem almost in its tracks. If another strain comes out that can get around it, then we've still got existing medications and the ability to adapt the shot to the new strain.
What would be best is if the treatment is cheap enough to administer in Africa (and if it's really effective, than that can be relative since I can see a lot of people and countries giving more money for something this big). Stopping AIDS in Africa could easily be the biggest medical achievement this century.
A gene therapy in humans that reawakens a gene we lost. The kicker? A kind of antibiotic cream can reawaken it without gene therapy!
PHEM - party like it's 1997-2003!
Worse than that -- some Africans believe that AIDS can be cured by having sex with a virgin. A belief not exactly compatible with halting the spread of the disease. The most effective immunization against HIV is information and education of the entire population. Antivirals don't cure the disease, but they can certainly prevent the taker from infecting others if used in accordance with doctor's orders.
I've abandoned my search for truth; now I'm just looking for some useful delusions.