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883General: Cancer/Interleukin-2 - "State of Siege"

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  • Janice and Ben Haines
    Sep 7, 1998
      Greetings,
      The following is from the book, "An Incomplete Education", written by Judy
      Jones and William Wilson, 1995, page 524-525.

      I thought it was a well written chapter on what happens to the body when
      there is a foreign invader. Also, I need to use this in my latest research
      on Interleukin-2 and how it relates to angiostatin and endostatin. Not the
      reference to interleukin-2 where I retyped the section from 'An Incomplete
      Education."

      Welcome new subscribers to the NHL-low team, now at: 313

      Regards,
      -Ben (KIA)

      From the National Cancer Institute:
      http://207.121.187.155/NCI_CANCER_TRIALS/zones/PressInfo/Angio/QA.html
      -----8<-----8<---
      <snip>
      13) Are there compounds that had promising results in mice
      but proved less successful in treating human cancers?

      Yes, many. A prime example is interleukin-2. In the 1980s, this
      drug was very successful in treating tumors in mice. But subsequent
      studies in people showed that interleukin 2 caused significant side
      effects, such as severe drops in blood pressure and the leaking of
      fluid from blood vessels. These difficulties in people were not
      predicted based on the mouse studies. A large number of
      chemotherapy drugs have much greater effectiveness against mouse
      tumors than against human cancers.

      -----8<-----8<---
      From: 'An Incomplete Education', page 524-525

      STATE OF SIEGE

      In the last twenty-five years, researchers have pieced together a picture
      of what happens when a foreign invader (e.g. a virus, bacterium, or
      parasite) enters the body. First, the army -- our trillion white blood
      cells, born in the bone marrow --- is alerted. These cells are of two major
      kinds: phagocytes ("cell eaters") that constantly patrol the body looking
      for intruders to devour, and lymphocytes, little commandos called T and B
      cells (T is for thymus, a small gland in the neck where T cells mature, B
      for bone marrow, the birthplace of B cells.)

      The soldiers in this army communicate via special proteins called
      cytokines. (Yes, of course, the military metaphor is tired, but "the body's
      bowling team" just doesn't cut it.) At the first sign of attack, special
      phagocytes, called macrophages begin to swallow up the enemy, taking from
      each the equivalent of its dog tag --- a tiny piece called the antigen,
      which a macrophage then displays on its own surface to attract helper T
      cells trained to recognize that particular antigen. (The thymus apparently
      has on hand a T cell able to recognize each of nature's hundreds of
      millions of antigens.) The macrophage secretes a cytokine called
      interleukin-1 and interleukin-2, which causes the creation of still more
      helper T cells and of killer T cells, whose job it is to clobber body cells
      already taken over by the invader. The new helper T cells release a
      lymphokine that orders the production of B cells in the spleen and lymph
      nodes. (Gives a whole new meaning to the term "sick day," doesn't it?)

      Helper T cells then produce yet another lymphokine that tells B cells it's
      time to stop reproducing and start making antibodies, proteins tailored to
      fight specific antigens. The B cells are capable of creating millions of
      different antibodies, which either fight the invaders or flag them so
      phagocytes can recognize and devour them. The helper Ts, bless 'em, also
      secrete gamma interferon, a lymphokine that boosts T cell activation,
      assists B cells in producing antibodies, and helps macrophages digest the
      enemy.

      When the invaders are vanquished, suppressor T cells tell the rest of the
      immune system to call it quits. Turning off the immune response is as
      important as launching it; some forms of blood cancer seem to be the result
      of T and B cells gone wild. And the immune system can mistakenly attach
      the body's own cells, as in such autoimmune diseases as rheumatoid
      arthritis and systemic lupus erythematosus. (Allergies are basically an
      immune-system overreaction to harmless invaders like dust and pollen.)

      After the battle's over, phagocytes clean up the debris --dead cells,
      spilled protein fragments. Certain B and T cells, called memory cells,
      remain in the blood and the lymphatic system, on guard against renewed
      attack by the same antigen. Vaccination is sort of basic training for
      memory cells; it introduces dead or weakened disease causing substances
      into the body, priming memory cells so they'll recognize the invader should
      it ever appear again in full force.

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