Study: Mast cells have a good side

STANFORD, Calif., Sept. 4 (UPI) -- U.S. medical scientists say mast cells -- known to trigger inflammation associated with allergies -- can also help resolve such reactions.

Stanford University School of Medicine researchers have discovered that, in mice, mast cells help decrease skin damage over time from exposure to sun or from poison oak.

"These reactions are much worse if mast cells aren't present," said senior author Dr. Stephen Galli, the school's chairman of pathology.

Galli said the findings, which might lead to new treatment for such maladies, contradict mast cells' reputation for causing allergic reactions. Located beneath the skin and in the body's connective tissue, mast cells contain inflammation-inciting molecules such as histamine and sometimes also react to non-threatening materials such as pollens or plant oils.

Such interactions cause allergic reactions and, in extreme cases, a life-threatening overreaction of anaphylaxis. Mast cells also affect the severity of eczema and asthma, giving rise to some therapies that focus on counteracting their activity.

But Galli's lab has shown mast cells can help fight, rather than just produce, distress.

The study is detailed in the online version of the journal Nature Immunology.