This article discusses a new understanding of how allergens trigger allergic reactions. Here’s a breakdown of the key points:
1. Finding of Pore-Forming Proteins in Allergens:
Researchers in Beijing identified two proteins, Aeg-S and Aeg-L, from the mold Alternaria alternata.
These proteins are responsible for triggering airway inflammation, a common symptom of allergic reactions.
They work by creating pores in the membranes of cells lining the nose, throat, and lungs.
2. Mechanism of Action:
The pores allow calcium ions too enter the cells.
This influx of calcium triggers the release of molecules that signal the immune system to a perceived danger.
The damage to cell membranes caused by these proteins is proposed as a “common signal” for the body to recognize something as an allergen.
3. Experimental Evidence:
When lung cells were treated with both Aeg-S and Aeg-L simultaneously,they showed an immune response similar to exposure to the whole A. alternata extract. Administering the proteins individually did not produce the same response.
In mice, intranasal management of these proteins lead to immune responses similar to A. alternata exposure.
Mice given the proteins repeatedly developed signs of respiratory allergy, including increased levels of serum immunoglobulin E (IgE), an antibody associated with allergic responses. This effect was not seen when proteins were given separately or when the mold lacked these specific proteins.
4. Broad Applicability of the Discovery:
the researchers tested this hypothesis by exposing mice to pore-forming proteins from other allergens, including:
Aspergillus niger (airborne mold)
actinia equina (sea anemone venom)
Eisenia fetida (earthworm)
Pleurotus eryngii (king oyster mushroom)
clostridium perfringens (bacterium)
Laetiporus sulphureus (fungus)
In all these cases, the pore-forming proteins induced similar immune responses and allergic airway inflammation.
5. Implications for Understanding Allergies:
This discovery suggests that unrelated allergens can trigger allergic reactions through a common mechanism involving conserved pore-forming proteins.
This offers a “new way of thinking about allergens.”
Future treatments could possibly target and block or inactivate these pore-forming proteins to prevent allergic reactions.
6. future Research Directions:
The researchers are investigating which specific immune-response pathways are activated by pore-forming proteins.
They also aim to determine if allergens that don’t* form pores (like those in dust mites or pollens) utilize the same pathways.
