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."
...for all the HIV-analogous-positive monkeys.
THL phish sticks
It would seem to me like this would maybe work for a year or so, and then there'd be some new strain that these antibodies might not hit.
I spent many years in medical school doing research work on viruses, including work with SIV. This article is very optimistic in some of its summaries. HIV and SIV are qualitatively different in the extent of "hypervariability" in their surface proteins. It is generally accepted to be "easier" to create antibodies to SIV, which has been done for many years.
http://www.ncbi.nlm.nih.gov/pubmed/7865316?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DiscoveryPanel.Pubmed_Discovery_RA&linkpos=1&log$=relatedarticles&logdbfrom=pubmed
The technique described is very interesting, don't get me wrong, and I hope it works. However, there are *already* many techniques that appear to immunize against this HIV analog, which do not work for human HIV. The two are significantly different.
Slashdotter, ID #101. UIDs are in binary, right?
Does the direct injection of large sums of money also work for simians?
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.
The analog version is obviously superior. I can feel the soft, velvety texture of the analog virus whereas the digital version seems rough and blocky.
Is it safe again to screw the monkeys or not?!
I will not be pushed, filed, stamped, indexed, briefed, debriefed or numbered. My life is my own.
Yeah, you're probably one of those people that insist on spending a fortune on glass syringes with exotic wood plungers and gold-plated needles, because they feel healthier.
Ignorance is the root of all evil.
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!
Injecting the antibodies directly does neutralize the virus, but unfortunately, the body's immune system recognizes those antibodies as foreign and so mounts an immune response against them (an anti-antibody antibody, if you like), which clears them from the bloodstream. So you'd need regular injections of neutralizing antibodies to maintain a therapeutic concentration in your blood. To quote the paper: "Passive immunization schemes using neutralizing antibodies have protected monkeys from SIV or simian-human immunodeficiency virus (SHIV) challenge infections. Unfortunately, an injection of antibodies every few weeks is neither practical nor cost effective as a large-scale human vaccine approach."