Health Editor’s Note: When bacteria can disguise themselves as normal human cells and thus evade the immune system we are in for a world of “hurt.” Our body’s defense against harm is in how quickly the immune system recognizes a harmful invader and begins the fight to eliminate the invader. If the body does not recognize a harmful invader this places the immune system into a state of incompetence, where the body may not even have the ability to raise the body temperature which is one of the signs of infection. In case you did not know, an elevated temperature is the body’s way of trying to kill the invader with increased heat, which will hopefully harm the bacteria or virus. Of course the body could not reach such high levels of temperature truly necessary to kill the invader without frying the body, but what does happen is that the elevated temperature will make a person sick enough to realize that he or she has an infection and needs to do whatever can be done to either ride out the infection or to seek treatment in the form of anti-bacterials or anti-virals. A bacteria that can gut a red blood cell, our oxygen carrying cells, and use it as a way to trick the body into not “seeing” the true harm, is a very insidious one. Much like a Trojan horse and we all know how that went….Carol
Harmful Bacteria Masquerade as Red Blood Cells to Evade the Immune System
by Katherine J. Wu/Smithsonian.com
Even single cells must sometimes be masters of disguise.
Various types of harmful bacteria, for example, masquerade as human cells to evade the immune system, blanketing their surfaces with molecules that resemble our own. The clever trick effectively gives the pathogens “cloaks of invisibility,” says David Gonzalez, a biochemist and microbiologist at the University of California, San Diego.
Now, Gonzalez and his team have discovered a new form of this microbial mimicry that’s especially macabre. To avoid being snuffed out by the immune system, the bacteria that cause strep throat tear apart red blood cells and then dress themselves in the debris, as reported today in the journal Cell Reports.
When this strategy works, the bacteria, called Group A Streptococcus (group A strep), remain concealed while they wreak havoc on the body, the study’s mouse experiments show. But when a protein in the bacteria responsible for the sanguine disguise is snipped out of the strep genome, the microbes are left exposed, allowing the immune system to attack the pathogens and prevent a potentially deadly infection.