Another productive afternoon totally wasted reading fascinating stuff on the Web. (We're drowning in knowledge, too.)
Always distracted by interesting misappropriations of theories of the immune system, I came across the interesting ideas and equally interesting life story of barmaid-turned-scientist Polly Matzinger and her revolutionary Danger Model, which is proving useful in fields far beyond medicine.
It isn't really insurrectionary -- it's just a different way of looking at things. Let me use an analogy to explain it. Imagine a community in which the police accept anyone they met during elementary school and kill any new migrant. That's the Self/Nonself Model. In the Danger Model, tourists and immigrants are accepted, until they start breaking windows. Only then do the police move to eliminate them. In fact, it doesn't matter if the window breaker is a foreigner or a member of the community. That kind of mutant behavior is considered unacceptable, and the destructive individual is removed. The community police are the white blood cells of the immune system. The Self/Nonself Model says that they kill anything that enters the body after an early training period in which "self" is learned. In the Danger Model, the police wander around, waiting for an alarm signaling that something is doing damage. If an immigrant enters without doing damage, the white cells simply continue to wander, and after a while, the harmless immigrant becomes part of the community.
A good introduction to Matzinger's theory and its implications is her article , "The Danger Model: A Renewed Sense of Self" (Science 2002 296: 301-305), which can be read here.
Perhaps, if we move from the idea that every lymphocyte should be directed against non-self antigens whose appearance stimulates the response, and consider instead the possibility that immunity is controlled by an internal conversation between tissues and the cells of the immune system (53), we may regain a renewed sense of the self that we have lost.
Matzinger has quite an interesting story, herself. According to her entry in Wikipedia,
Polly Matzinger is now a section head at the National Institute of Allergy and Infectious Diseases and her "danger model" suggests that the immune system is more concerned with damage detected on the basis of cell death rather than with foreign invaders. In one of her first publications, she coauthored a paper with Galadriel Mirkwood for the Journal of Experimental Immunology. The journal barred Matzinger for 15 years [or] "until the editor died" since it turned out that the coauthor was an Afghan Hound which according to her was as much involved in research as many other coauthors. She took to science from an unusual background career path which included stints as a playboy model, jazz musician and bar waitress. To many she stands as a symbol of the scientific spirit and its openness.
In the HP Labs in the UK, the Danger Theory is being applied by Steve Cayzer to "artificial immune systems" such as computer security.
Danger Theory is not about the way Artificial Immune Systems represent data. Instead, it provides ideas about which data the Artificial Immune Systems should represent and deal with. They should focus on dangerous, i.e. interesting data. It could be argued that the shift from non-self to danger is merely a symbolic label change that achieves nothing. We do not believe this to be the case, since danger is a grounded signal, and non-self is (typically) a set of feature vectors with no further information about their meaning. The danger signal helps us to identify which subset of feature vectors is of interest. A suitably defined danger signal thus overcomes many of the limitations of self-nonself selection. It restricts the domain of non-self to a manageable size, removes the need to screen against all self, and deals adaptively with scenarios where self (or non-self) changes over time.
It's conceivable, too, that such an approach might prove more useful in targeting terrorists than declaring as nonself anyone who comes from the wrong part of the world or holds unpopular opinions.
Later, there was very weird synchronicity to these metaphors of autoimmunity when I caught a radio essay about a Jewish guy who utterly rejected Klezmer unless it was played by a black jazz musician ...