Allergens that chop up a clotting protein contribute to reactions
A common blood-clotting protein turns out to play a role in allergic asthma. The protein interacts with better-known immune system players already implicated in allergy, providing a missing piece of the biological puzzle underlying such respiratory attacks. The finding exposes a biological chain of events that could offer targets for allergic asthma treatments, researchers say.
Asthma symptoms triggered by allergies are marked by inflammation of the respiratory tract, which leaves a person gasping for breath, coughing and wheezing. There are many players in this overreaction, including an immune protein called TLR4, or toll-like receptor 4, and enzymes in fungi and other allergens called proteinases.
In the new study, a team of scientists induced allergic asthma attacks in mice by exposing the animals to proteinases found in molds, which are common fungal allergens. These proteinases break down a blood-clotting protein called fibrinogen. The resulting shards of fibr