Researchers have found that mice lacking a specific immune cell are unable to develop asthma. Asthma is as a result of airway hyper-reactivity (AHR) which is narrowing of the tiny passages in the lungs in response to a trigger such as house dust mite. AHR is triggered by the immune system and leads to the characteristic wheezing and coughing symptoms of an asthma attack. Researchers at Stanford University have been studying mice that lack a specific type of immune cell called natural killer (NK) cells. These mice do not get asthma, despite being exposed to the usual triggers.
The researchers suggest that maybe people with asthma have abnormally large numbers of NK cells in their lungs, or that their NK cells are abnormally responsive. Further research which targets NK cells will be a good new approach in asthma therapy.