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Immune System Killer Mechanism Identified

Posted by samzenpus on from the cancer-killer dept.

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."

10 of 88 comments (clear)

  1. Doh by Anonymous Coward · · Score: 5, Funny

    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!

    1. Re:Doh by sempir · · Score: 3, Funny

      Actually, relaxin and respiratin are also important. Relaxin causes the sphincter to relax, respiratin causes it to inhale, and then finally perforin can do its work. :)

      When "perforin" work is finished it returns to the sphincter and, "fartin" then occurs which causes the sphincter to....exhale!

      --
      A closed mouth gathers no foot.
  2. Why am I reminded of the Wizard of Earthsea? by mellon · · Score: 3, Interesting

    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.

    1. Re:Why am I reminded of the Wizard of Earthsea? by Kilrah_il · · Score: 4, Informative

      It's not the first time that doctors lowered/raised the level of activity of a protein involved with the immune system. Of course it has side effects, but a drug gets approved when the benefits outweigh the risks.
      For example, TNF is an important mediator of inflammation. Its inhibitors are used for Rheumatoid Arthritis and many other diseases.
      Interleukin-2 is also an important factor in the immune system (esp. in its anti-viral and anti-cancer capacity). A recombinant form of this protein is used to fight several types of cancer.
      So, yes, maybe this approach won't work, but it has potential and it will be a shame if it will not be tried.

      Oh, and by the way, thanks for the Wizard of Earthseas reference. I read this book years ago, and never could remember its name.

      --
      Whenever in an argument, remember this.
    2. Re:Why am I reminded of the Wizard of Earthsea? by gilleain · · Score: 3, Interesting

      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.

      The best example of this, I think, is the theory of balance between cancer and auto-immune disease. The idea is based on the fact that cancer involves cells growing out of control, while auto-immune disease (like arthritis) involves the immune system attacking the self. So a more active immune system will lead to arthritis, and a less active one to cancer - and you can't just suppress or boost immune cell-killer response without consequence

  3. Better HIV drugs by antifoidulus · · Score: 4, Insightful

    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
  4. Immune System Killer Mechanism Identified by The_mad_linguist · · Score: 3, Funny

    Immune System Killer Mechanism Identified

    oh nooooooo

  5. This function discovered in 1985 - this is not new by Invicta{HOG} · · Score: 4, Informative

    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.

  6. Re:This function discovered in 1985 - this is not by The+Mysterious+Dr.+X · · Score: 4, Informative

    I was going to say the same thing, but my article is only from 2007... http://www.ncbi.nlm.nih.gov/pubmed/17717151

  7. Re:This function discovered in 1985 - this is not by Anonymous Coward · · Score: 5, Informative

    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.