Danger Dust - What Else?

The immune system senses damage to cell membranes caused by pore-forming proteins and mounts a response.

Before this, the mechanism that triggers immune responses to allergens was not really understood. Researchers focused mostly on how a single allergen elicits a reaction, rather than looking for a generalizable mechanism.

The results could also change allergy-treatment strategies, which typically target the allergen directly or downstream immune responses. Now, researchers can start looking for ways to target the hole-creating proteins that are initiating the immune response, Ryan says.

Pore-forming proteins

Researchers based in Beijing, China, identified two proteins in the mould Alternaria alternata, which causes allergic reactions in about 5% of people, that trigger the airway inflammation seen during allergic reactions.

Together, the proteins, called Aeg-S and Aeg-L, create a pore in the membranes of cells lining the nose, throat and lungs. This allows calcium ions to enter the cells and release molecules that alert the immune system to danger. The damage to cell membranes from these pore-forming proteins could be a “common signal that our body uses to recognize something as an allergen”