Human Immune System Has Emergency Backup Plan (Excerpted from Science Daily -- full article at that URL)
ScienceDaily (Dec. 27, 2010) � New research by scientists at the University of California, San Diego School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences reveals that the immune system has an effective backup plan to protect the body from infection when the "master regulator" of the body's innate immune system fails. The study appears in the December 19 online issue of the journal Nature Immunology.
A molecule known as nuclear factor kappa B (NF-κB) has been regarded as the "master regulator" of the body's innate immune response, receiving signals of injury or infection and activating genes for microbial killing and inflammation.
"We discovered that loss of NF-κB caused mice to produce a potent immune-activating molecule known as interleukin-1 beta (IL-1β), which in turn stimulated their bone marrow to produce dramatically increased numbers of white blood cells known as neutrophils," said Karin.
The new research demonstrates that the innate immune system deploys two effective strategies to deal with invasive bacterial infection, and that the IL-1β system provides an important safety net when NF-κB falls short.
While helpful in short-term defense against a severe bacterial infection, the dramatic increase in neutrophil counts seen in the NF-κB-deficient mice ultimately came at a cost. Over many weeks, these activated immune cells produced inflammation in multiple organs and led to the premature death of the animals.
Long-term blockade of NF-κB signaling has been explored extensively by the biotechnology and pharmaceutical industry as a strategy for anti-inflammatory or anti-cancer therapy, perhaps unaware of the risks suggested by this new research.
"One might contemplate adding a second inhibitor of IL-1β signaling to protect against the over-exuberant neutrophil response," said Karin. "Unfortunately, loss of both the NF-κB pathway and the backup IL-1β pathway rendered the mice highly susceptible to invasive bacterial infection which they no longer cleared."
Posted by Heleneh (Member # 21207) on :
Good to know this. But also scary for people who can't seem to get rid of chronic inflammation no matter how hard they try.