Good news for LGND's IL-4 antagonist program to treat asthma:
Thursday May 21 6:03 PM EDT
Asthma-triggering cell identified
NEW YORK (Reuters) -- The cause of the chronic inflammation that underlies asthma has long been a mystery, but now
researchers believe they have identified the type of immune cell that may be responsible for the lung disorder.
According to a report in the May 22nd issue of Science, a subset of white blood cells, known as gamma delta T cells, appear
to drive the reaction that results in two of the hallmarks of asthma: the infiltration of the lungs with inflammatory cells and the
lung's hypersensitive response to allergens or toxins.
Dr. Claudia Zuany-Amorim and colleagues at the Institut Pasteur in Paris, France, bred a special strain of mouse that lacked
gamma delta T cells. Unlike normal mice, the T cell-deficient mice did not have a dramatic increase in inflammatory cells in the
lungs and blood after exposure to an asthma-inducing protein.
An analysis of lung fluid showed that the T cell-deficient mice also produced lower levels of certain growth factors, including
interleukin 5 (IL-5), interleukin 4 (IL-4) and interferon, as well as less IgE, an antibody responsible for allergic reactions.
However, injecting the T cell-deficient mice with IL-4 restored the asthma-like reaction, suggesting that the growth factor plays
a key role in the immune reaction. Further research into the function of gamma delta T cells "...will represent an important step
for understanding and modulating" the immune response that leads to asthma, the researchers concluded. SOURCE: Science
1998;280:1265-1267.
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