10 Feb 2012
IMMUNOLOGY: How a stomach-colonizing bacterium protects against asthma
The bacterium Helicobacter pylori can be found colonizing the stomach lining of almost half the world’s population. Although persistent infection with Helicobacter pylori increases an individual’s risk of developing stomach cancer, it also decreases their risk of developing asthma. A team of researchers led by Anne Müller, at the University of Zürich, Switzerland, has now identified a cellular mechanism by which persistent infection with Helicobacter pylori protects mice from developing allergic asthma. Specifically, they found that Helicobacter pylori modulated immune cells known as dendritic cells such that they did not activate an aggressive immune response but instead activated what is known as a tolerogenic immune response. Although this tolerogenic immune response enabled Helicobacter pylori to persist, it also prevented the onset of unwanted immune responses to allergens (that is, it protected against allergic asthma).
As noted by Kouji Matsushima and Shigenori Nagai, in an accompanying commentary, these data provide new mechanistic insight into the intriguing link between the recent sharp rise in the industrialized world in the number of people with asthma and the simultaneous decrease in exposure to microbes, including Helicobacter pylori.
TITLE: DC-derived IL-18 drives Treg differentiation, murine Helicobacter pylori–specific immune tolerance, and asthma protection
- ‘Bad’ Gut Bacteria May Help Control Diabetes (medicalnewstoday.com)
- URI scientists, collaborators closer to designing vaccine for H. pylori pathogen (uriprovidenceblog.wordpress.com)
- News From The Journal Of Clinical Investigation: Feb. 6, 2012 (medicalnewstoday.com)
- Helicobacter pylori targets dendritic cells to induce immune tolerance, promote persistence and confer protection against allergic asthma. (polygenicpathways.blogspot.com)