"Daedalus dilemma" of the immune system

Our immune system constantly fights off bacteria and viruses and while doing so needs to find a critical balance between overand under-reaction, similar to Daedalus and Icarus in Greek mythology who must neither fly too high nor too low to escape their captivity. How this balancing act is regulated at the molecular levels was so far poorly understood. First insights are now provided by Pavel Kovarik and his team from the Max F. Perutz Laboratories of the University of Vienna and the Medical University of Vienna. The group reports that in the defense against group A Streptococci - bacteria that cause tonsillitis but also serious and sometimes fatal invasive infections - a perfectly synchronized interplay of two immune substances is key. The molecules IL-1? and type I interferon control the strength of the immune response similar to a rheostat that varies the resistance in a circuit. The results are published in "Cell Host & Microbe" and offer new approaches to the treatment of severe streptococcal infections. Similarities between Greek mythology and the immune system The dilemma of our immune system is comparable to the story of Icarus and Daedalus from Greek mythology. To escape their captivity, Daedalus built wings from feathers and wax for himself and his son. Daedalus warned his son that he must neither fly too high but also not too low, otherwise the sun's heat or the humidity of the sea would destroy his wings and he would crash. After they had successfully escaped, Icarus became boisterous and flew higher and higher until the sun began to melt the wax of his wings and he fell into the sea. Similarly, an overor under-reaction of our immune system can be life-threatening. The molecule IL-1? plays a key role in the balanced defense against bacteria