What bothers the natural killer cells?

The innate immune system, which contains cells from the lymphoid branch, includes one of the first defense lines in the battle against viral infections and cancer: natural killer (NK) cells. NK are critical for the immune response, since they are able to respond to threats without prior sensitization. The efficacy of NK activity is somewhat impaired, however, as a significant percentage of the NK are not appropriately educated. For proper function, NK cells should express classical inhibitory receptors. Lacking these, the cells become inefficient, or "anergic". The molecular mechanisms leading to the anergic condition, as well as those underlying NK cell exhaustion that arises from overstimulation in chronic conditions, remain unknown. In an article published in The EMBO Journal, Prof. Mira Barda-Saad and her team unravel the process leading to NK dysfunction. Moreover, they describe a way to re-activate NK cells using nanoparticles, which may be used for the clinical development of immunotherapeutic treatments.