Breakthrough in Respiratory Allergies: Key Inflammatory Molecule Identified

A groundbreaking discovery by researchers at CNRS, Inserm, and Université Toulouse III — Paul Sabatier has unveiled a new molecule from the alarmin family, named TL1A, that plays a pivotal role in the onset of inflammatory responses in allergic respiratory diseases like asthma and allergic rhinitis. Published in the Journal of Experimental Medicine, this finding opens new doors for targeted therapies that could revolutionize the treatment of these prevalent conditions.

Breakthrough in Respiratory Allergies: Key Inflammatory Molecule Identified 1

The Role of the Pulmonary Epithelium in Allergic Diseases

The pulmonary epithelium, which lines the inner surface of the lungs, has long been recognized as a critical player in respiratory inflammation that underlies diseases such as asthma and allergic rhinitis. However, the specific mechanisms by which this epithelium contributes to disease have remained largely enigmatic, with researchers striving to decode the complexities involved.

Discovery of TL1A

The newly identified molecule, TL1A, is part of the alarmin family—a group of proteins known for their role in initiating immune responses. TL1A is released by lung epithelium cells shortly after exposure to allergens, such as mould, marking the beginning of an allergic reaction. This discovery was made possible through collaborative research led by Corinne Cayrol and Jean-Philippe Girard at the Institut de pharmacologie et de biologie structurale.

The Double Alarm Signal

TL1A does not act alone; it works in conjunction with another alarmin, interleukin-33 (IL-33). Together, these molecules form a “double alarm signal” that awakens the immune system to the presence of an allergen. This signal dramatically enhances the activity of immune cells, leading to the cascade of reactions that manifest as allergic inflammation. Understanding this dual mechanism provides significant insight into the inflammatory processes that could be interrupted to prevent or mitigate allergic responses.

Implications for Treatment

The identification of TL1A as a key factor in allergic inflammation positions it as a major therapeutic target. Potential treatments could involve antibodies designed to block TL1A, thereby preventing it from triggering the immune response associated with allergic diseases. Such treatments promise substantial improvements in the quality of life for individuals suffering from severe asthma and other allergic conditions.

Current Impact and Future Directions

In France alone, allergic diseases affect at least 17 million people, with the most severe forms of asthma causing several hundred deaths annually. The discovery of TL1A not only enhances our understanding of these diseases but also lays the groundwork for developing medications that could reduce these significant health burdens.

Future research will likely focus on developing and testing TL1A-blocking antibodies in clinical trials to assess their safety and efficacy. Additionally, scientists aim to explore the broader role of alarmins in other inflammatory diseases, potentially extending the impact of this research beyond allergic respiratory conditions.


The discovery of the TL1A molecule as a trigger for allergic inflammation represents a major advancement in allergy and immunology research. By targeting this molecule, new treatments could effectively prevent the severe symptoms associated with asthma and allergic rhinitis, transforming the lives of millions who currently suffer from these conditions. As research progresses, the hope is to apply these findings not only to improve treatments but also to develop preventive strategies that could one day eradicate the threat of severe allergic diseases.

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