Nevco News
March 2009
Volume 2, Issue 3
Our Lungs As Part Of Our Immune System
|
Lungs are delicate and exposed to the environment, almost like
an open wound. Consequently, the body has developed an elaborate
immuno-defense system to combat inhaled pathogens and bacteria –
in a healthy individual, this system effectively blocks hundreds
of potentially sickening assaults daily. It works like this: airway epithelial cells initiate an immune response to inhaled bacteria by signaling for white blood cells to move from the bloodstream into the lungs and airway to fight potential infection. For the first time, researchers at Columbia University Medical Center have demonstrated that this signaling cascade includes the activation of epithelial proteases, a type of enzyme capable of opening the junctions between the cells in the airway mucosa, to enable the white blood cells to get through to the site of the infection. The opening of these junctions is initiated by a change in calcium levels. |
Getting white blood cells to the site of an infection, however,
is often a double-edged sword. On the one hand, having as many
white blood cells as possible at the site of an infection is
beneficial, but on the other hand too many white blood cells can
lead to excessive inflammation, interfering with breathing and
damaging the airways. Cystic fibrosis is one disease where this work might have particular import, Dr. Chun says. People with cystic fibrosis possess an abnormal gene that causes normal mucus to become thick and sticky, leaving the lung more prone to infection and inflammation, while still killing infection-causing bacteria. The findings, in mice, demonstrate a way to inhibit proteases and restrict the junctions between cells in the airway mucosa, meaning that fewer white blood cells can get into the airway – causing less inflammation. |
Columbia University Medical Center (2009, January 29). Research Elucidates Way Lungs Fight Bacteria And Prevent Infection. ScienceDaily. Retrieved February 9, 2009 |
