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Self-Harm for Self-Defense

To protect themselves during malaria infections, mice can kill their own healthy red blood cells, cutting off the parasite’s primary resource.

By | June 20, 2012

image: Self-Harm for Self-Defense FLICKR CREATIVE COMMONS, AUSSIEGALL

FLICKR CREATIVE COMMONS, AUSSIEGALL

Mice infected with the malaria parasite can purposely damage their own healthy red blood cells to defend themselves against the invader, which thrives by infecting new blood cells. This phenomenon, once thought to be an unintended side effect of the immune system response to infection, appears instead to be an effective measure the reduce the virulence of the parasite, according to a study published yesterday (June 20) in Journal of the Royal Society Interface.

“The immune system is really judiciously killing red blood cells at exactly the moment where it will maximally slow down the parasite’s growth rate,” said evolutionary ecologist and co-author Jessica Metcalf of Oxford University. “So it’s self-harm for self-defense.”

Malaria parasites multiply within red blood cells until they burst, releasing new parasites to seek out new cells and propagate the infection. This cycle tends to happen in waves, so that at the time of bursting, patients carry significantly fewer red blood cells than normal, causing them to become anemic.

To tease apart the host-pathogen relationship, Metcalf compared the number of infected and uninfected red blood cells at various time points for 20 days in mice. She then estimated the average number of newly infected cells per previously infected cell, and correlates that measure, called the reproduction ratio, with other factors, such as disease symptoms, the available supply of healthy red blood cells, and the effectiveness of the host immune response.

Of the eight malaria clones the team tested, the most virulent were also more transmissible, confirming a long-time assumption of parasite dynamics: the more destructive a parasite is to its host, the more quickly it will have to find another, or face extinction. However, the researchers found that the timing and magnitude of transmission of the parasite could not always be predicted based on virulence alone, indicating that the parasites were using different tactics to acquire resources, evade the immune system, and spread to new host cells.

“The idea is that each of these strains differ in the harm they cause,” theoretical biologist Samuel Alizon of the Institut de Recherche pour le Développement in France, who was not involved in the work,  said by email.

One factor that could play a role is the dominant age of red blood cells. As an infection persists and the older blood cells are killed by parasites, the overall population of blood cells becomes much younger. In previous studies, different clones have shown preference for infecting either old or new cells, in which case different strains of the parasite should be favored at different points in the disease progression. But what kind of immune response a clone elicits, including the self-killing mechanism that the team discovered, is also likely to be key in influencing parasite transmission, Metcalf noted. By sacrificing their own red blood cells, the mice can limit the parasite’s ability to spread, and ultimately save more bloods cells in the long run.

The apparent “guerilla action” of the immune system in killing uninfected red blood cells gives new insight into how natural variations in immunity may work. For once, an overactive immune system may be a good thing, helping to control the spread of infection within the body. While Metcalf says there is still a lot unknown about the complex interactions, the research suggests another way in which immunity works to stop invading pathogens in their tracks.

Malaria in mice is much more aggressive and acute than in people, however, so the application of the findings to the human disease remains unclear. But Metcalf believes that the knowledge that parasite virulence stems from a variety of mechanisms could impact the development of new treatments. “If you know that the parasites are doing very different things, then that tells you something about…[the] different impacts of different treatments.”

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Anonymous

June 21, 2012

I know a mouse.  His nickname is Mickey.  He lives in California, and plays in movies.

Isn't it marvelous how Mickey, and other personified abstraction mice, seeing a problem, take the bull by the horns and solve it?

Look at this quote originated in the article:  "To protect themselves during malaria infections, mice can kill their own
healthy red blood cells, cutting off the parasite’s primary resource."

This is science?  If it is informative, what educational level is it supposed to communicate something significant to --  pre-schoolers?

Picture this.  We have called together researchers as many different cutting-edge research projects as we might hope to provide a representative cross-section of what all is going on at the frontiers.  The house lights dim, come back up, and after another minutes go dark, and at down-stage-center the spotlight is on a single, highly renouned bio-evolutionary theorist.  He clears his throat and begins to speak.  He begins with a quote, quoted from the paper the instant article is about, saying:

“The immune system is really judiciously killing red blood cells at
exactly the moment where it will maximally slow down the parasite’s
growth rate.  So it’s self-harm for self-defense."

This is science??????

I had a red pickup truck once that wanted to remain operable and mobile and a participant in traffic jams.  One day a utility trailer unloosed itself from another pickup truck and veered right into the center front of that pickup, caving in its front bumper and grill and radiator and cooling fan.  So, what did that red pickup do?  It harmed itself, by self-harming, in that it absorbed most of the force in its bumper, grill, radiator and fan, in order to preserve its frame and its engine.  You see, if it had not harmed itself by selectively distributing the momentum of that trailer, its engine and/or its frame would have shared the force of the blow, and that red truck would have ended up victim to cannibal machines, such as impact wrenches and cutting torches and gosh knows what all.  By the way, those cannibal tools are no fools either.  They bring along humans with them, when they come to cannibalize.

Metaphors are not exactly stupid, or unpersonifiable, either.  They, too, use mice and humans and whatever else may be at hand to do their thingee, too.  And, do they sometimes self-harm in order to survive?  You betcha'.  One kind of example is when they sacrifice some of their self-survival power in one way, to gain advantage of another way.  For example, they will use the human they are exploiting by giving up a portion of what they would convey along one semantic vector, in order to avail themselves of survival benefit of another as, for example, when they reframe themselves engeniously into becoming a part of a mixed metaphor, or a pun or -- perhaps most clever of all -- when they take advantage of an opportunity to gain by way of a cause peripheral to where they would first seem to be taking things so as avoid becoming ignored or forgotten, and -- to accomplish survival -- avail themselves of an opportunity to present a double entendre (particularly one of what might be mistaken for an innocent  Freudian slip.  (It does not go unnoticed by us who rigorously parse the self-serving-even-if-it-requires-partially-self-sacrificing actions of self-preservation by metaphors, whereby they get humans to behave in their (the metaphors') self-interests -- as well as other aspects of their environment.  By tricking humans to do such metaphor perpetuating things as engage in suggestive inuendo, or other kinds of what might tend to result in reparte that in turn may lead to their breeding-  a metaphor plays the role of participating in the manipulation of humans to have offspring.  Were it not so, and all humans forget to reproduce for a generation, metaphors would die of paucity of humans to use to go on living by being used by the major (or possibly only???) vehicle that enables them to occur.

Of course, metaphors and red pickup trucks, and mice like Mickey sometimes are not given all the credit they deserve for their clever, creative resourcefulness, whereby they meme themselves into increase of their population.  As viewed from a macro scale dynamic in making themselves survive and evolve as they do, they are highly proficient at the game.  And that is why, and how, metaphors have evolved from the time the first one emerged itself into existence.  

As I've said elsewhere -- piercing off some devout macro-bio-evo apologists in the process: metaphors are not science, and science is not metaphors.

However, it may be that few humans are aware of the meaning and significance of the term:  AFFIRMING  THE  CONSEQUENT.

If my theory is correct, then by interactively engaging, and modifying themselves to  solve problems in their environment, they have survived and evolved over time.

Metaphors, and Mickey Mouse, and red pickups have, indeed, survived and evovled over time. 

Therefore, my theory of why and how they have done it is scientifically grounded and correct.

If it is NOT correct, then maybe there is at least one reader out there who sees the parallels between the way evolution works, and how mice and immune systems interactively perceive a problem, weigh solutions to it, pick one... and implement it.

Many other readers will be so bogged down in simplistic, metaphor-driven doctrine as to why and how evolution occurs, that they will perceive me to be saying it does not occur.

It occurs.  It occurs.  It occurs... okay?

Answers as to how it occurs are not, however... are not... are not... at the macro level where all we can do is confirm that it does occur, and make absurdly simplistic and unenlightening personifications and other kinds of rhetorical palaver to "explain" findings at the edge of research.

The REAL explanations may be NEAR being deciphered.  But they will be at scales of size where different dynamics apply than macro dynamics.

Biology is getting there, but is not there yet.  And pretending we can explain where we are at current day of progress would be humorous to all, if some of us could just get over being defensive about the great charade whereby we pretend we know more than we know, quite yet.  
FOOTNOTE (added after original of post) In saying that science is not metaphor and metaphor is not science, my meaning was not that explaining of science can be performed WITHOUT USE of metaphor. My meaning was that the tail of metaphor should not wag the dog of interpretation. It is my contention that the tail of metaphor in biological evolutionary theory not only wags the dog of interpretation of change over time; it DOMINATES it, shouts down questions raised about new evidence; and is MOST resorted to in argumentations backed by the very LEAST hard evidence of how things have come to be as they are today, and seem to work as they work today.

Another statement I have made, that goes along with this assertion, is that dogma is not science and science is not dogma. Dogma holds that something (even a consensus among all scientists on any given day) is self-evident, or obvious without any need of proof and, for these or any other reasons should NOT BE QUESTIONED. Science proceeds BY questioning things. Not to question is anti-science. Contesting a claim on part of any individual or group is NOT anti-science.

Such understanding comes easily to some. For others it comes only after much rigorous effort.
 

Avatar of: James Staples

James Staples

Posts: 1

June 22, 2012

I cannot help but to laugh at this....as I myself engage a 'self-harm for self-defense' type 'response'; in my case, taking certain life-span shortening pain medicines; to a 'disease'; in my case, H.N.P.P. - Hereditary Neuropathy with Susceptability to Pressure Palsies (aka: 'Bulb Planters Palsy' - apt, considering my 'roots' - and also as one of those Conditions which many people who, at one time or another, have 'responded poorly' to Carpal Tunnel Surgery actually had; and which was, often, the actual cause of their 'carpal tunnel-type' symptoms; but, because no one knew it, they ended up undergoing a 'contraindicated' procedure that left them worse off in the end! I know, Traction Therapy, which I've had far too much of, IS CONTRAINDICATED AS WELL!!!).
Of course, the Federal Congress of The United States of America could listen to Me/We, The Chronic Pain Sufferers of the United States of America, as well as the 1400+ Oregon Pysicians who signed on as "Chief Petitioners", in 2008, of the latest version of the Venerable 'Oregon Medical Marijuana Act', and pass a Federal Medical Marijuana Act.......as, after all, it was only because of Tricky Dick Nixons; you know, the only President of the United States of America to be impeaced, and then forced to resign in disgrace; failure to LISTEN TO the Venerable Scientists who submitted the equally venerable "Schaeffer Report" - in, what, 1972? - to Tricky Dick, and his decision to initiate the 'War on Drugs' in spite of it's admonitions to the contray, that led to my being put through that therapy; as it's the "War on Drugs" that is the reason they didn't know I had HNPP, or that such a Therapy was Contraindicated!
Why is that, you may ask?
Why, because - though I was already in some pain, and suffering from some pretty serious 'puberty boosted' chronic depression issues - I was labeled a "Pot Head", at Age 14; because, you see, I'm a Scientific Genius, and I "discovered", at Age 11 or 12, that I could SUCCESSFULLY treat BOTH of those serious medical conditions with this WONDERFUL and TIME HONORED Herb; and, so-o-o-o-o-oo, when I complained to my Pediatrician, at Age 15, about the 'shooting pains in my legs' - aka: A "Typical" example of "...onset of HNPP Symptoms usually occuring during the early teen years..." - I was told that I had "Ceivers Disease".
Or - "Deceivers Disease", which is an Imaginary Condition (usually found only in the minds of 'B-type personalities who've become "addicted" to self-help programs, and/or people are members of a 'Faith Based Organization' where they go to, "Get High on Jesus", and/or people who know how to lobby Congress very successfully) whose primary symptoms are "craving the 'Good Shit'".
Funny, after I became a Registrant of the aformentioned Oregon Rebellion I QUIT - quite Voluntarily, as Pot REALLY Works, you see - the 160mg of Oxycontin and the 20mg of Methadone that I'd been taking for Chronic Neuropathic Pain for over three years, by then.
You know - Oxycontin, Methadone; aka: The "Good Shit".

Avatar of: Roy Niles

Roy Niles

Posts: 32

June 24, 2012

Excellent article.  We have strategic systems operating in all our functions that regulate our internal systems in ways that our brain was not evolved to do.  We have used these strategies to both make new cellular structures to serve a myriad of purposes, and unmake them when needed in service of those same purposes.  There are intelligent operations going on in every one of our cells all the time.  Boggles the mind, and apparently also draws out the crazies to make their comments.  Which some will say includes me, but if so, these scientists were crazier, and more power to them.  Of course they work in England where adaptive mutation processes are better understood than in Creationist versus neoDarwinist America.  We have very little theoretical room for any biological system that in any way is alleged to be intelligently designed.

Avatar of: Valene_Chai

Valene_Chai

Posts: 4

July 1, 2012

So, mice never die from Malaria? Is it possible that the mice running out of healthy red blood cells?

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