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Immune System Killer Mechanism Identified
traveller.ct writes "Researchers from Melbourne and London have identified the mechanism by which the immune system destroys malignant cells. The notion of killer cells puncturing a malignant cell to inject toxic enzymes has been understood for over a century, but now, using the Australian Synchrotron, researchers have identified the protein which is responsible for forming a pore in the malignant cell: perforin. Perforin resembles the cellular weaponry employed by bacteria such as anthrax, but may have been appropriated by our immune system in our evolutionary past to fight against them. The researchers are now investigating ways to boost perforin for more effective cancer protection and therapy for acute diseases such as cerebral malaria."
Should have been pretty obvious from the start.
"Let's see which of the proteins is most likely the one used to perforate other cells.. we have relaxin, movearoundin, respiratin and perforin... hmmm!
When you tweak one thing, something else tends to go out of balance. Still, this is pretty cool, whether it leads directly or indirectly to new treatments.
I wonder if this finding will help researchers develop better anti HIV drugs. Part of the reason that HIV is almost impossible to remove from the body is its ability to remain latent, HIV viruses don't always start producing new virons and killing the cell right away, sometimes they enter a cell and essentially just sit there, sometimes for up to 5 years. Ordinarily the cell would be marked for execution, but HIV(and other viruses, notably the herpes family) somehow prevent the cell from making the chemicals necessary to let the immune system know that it's time to die. This is why people on HIV treatment can have 0 viral load(the amount of virus in a particular blood sample), but still be infected. They still have HIV just kind of hanging out in a very small number of cells.
I read a few years back(sorry cannot find the article) that they had some luck using epilepsy medication in combination with a huge dose of anti-HIV medication, patients saw about a 75% reduction in the number of infected cells, but the side effects were so severe that they discontinued the study. Not a single person was totally cured. I wonder if its possible to use the information gathered here to help determine how HIV prevents cell death and how we can stop this.
Monstar L
Immune System Killer Mechanism Identified
oh nooooooo
http://www.ncbi.nlm.nih.gov/pubmed/3874868
Perforin has been known for 25 years to be the mechanism by which immune cells kill other cells.
I was going to say the same thing, but my article is only from 2007... http://www.ncbi.nlm.nih.gov/pubmed/17717151
Don't know. Maybe because you've seen too many movies?
Just to allay your fears, this is a protein, meaning it cannot be ingested, since it will be broken in the gastrointestinal (GI) tract. The only effective way to give it to someone is by injection. Even then, these proteins are usually broken down quickly by the body (to prevent their overactivity). For continuous action the immune cells continue to secrete the protein until the job is done.
So basically, you need to hold on to the enemy soldier, put an intravenous line in him and give him the protein continuously until he dies from massive total system cell breakdown. Sounds like a regular Dr. Evil plot - No way can Austin Powers escape this one!
Whenever in an argument, remember this.
Perforin resembles the cellular weaponry employed by bacteria such as anthrax, but may have been appropriated by our immune system in our evolutionary past to fight against them.
or perhaps anthrax, and others, appropriated perforin from our immune system
i'm not saying one scenario is more likely than the other, but redirecting virtuous weaponry for evil is just as likely as salvaging malicious weaponry for good. molecular evolution is a highly promiscuous process, so, in the end, it might not even matter which came first, or possible to figure out which came first
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
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Actually, what the researchers have done is produce an X-ray crystal structure of perforin, which enables them to understand how it works and hopefully how to tweak it to our purposes. Could be an interesting drug, recombinantly engineered perforin targeting e.g. malaria or other protozoan diseases. It is of course just another of several attempts to use immune system derived proteins as medicines (antibiotics, anti tumour drugs etc), and will suffer the same problems: hard to administer, breaks down quickly, does not diffuse well through tissue to the target area.
The summary's statement that the researchers have "identified" perforins as the causative agent of cell membrane perforation is misleading, that has been known for quite some time, as you mention.
The detailed molecular mechanism has been know for sometime; what these workers did was to create a detailed 3D atom resolution model of the responsible protein perforin, while this will certainly help in understanding how pore forming proteins, which are widespread and often act as agents of disease, work, it is not consistent with the title.
oh, overblown article headline , taken from PR pretending to be news, on slashdot. Why am I surprised ?
note - I coudn't get the DOI at the bottom of the article to work , so if this is not published, it is not even *science*
Here is a review by author whisstock The structure and function of mammalian membrane-attack complex/perforin-like proteins. Kondos SC, Hatfaludi T, Voskoboinik I, Trapani JA, Law RH, Whisstock JC, Dunstone MA. Tissue Antigens. 2010 Sep 22. doi: 10.1111/j.1399-0039.2010.01566.x. [Epub ahead of print]PMID: 2086058