Scientists uncover how lung cells may block allergies for months

Respiratory allergies have surged worldwide over the past decade, driven by pollution, urbanisation, and climate change. Now, a new study led by researchers at France's Pasteur Institute suggests a potential way to prevent them by harnessing the lung's own structural cells.

The team discovered that exposing mice to bacterial or viral fragments before introducing an allergen prevented allergic reactions for at least six weeks. Without this initial protective exposure, the animals developed severe lung hypersensitivity, which worsened dramatically upon re-exposure to the allergen.

The key finding was that immunological memory for blocking allergies is stored not in immune cells, but in fibroblasts—connective tissue cells that support and bind organs. These fibroblasts undergo epigenetic changes, allowing them to 'remember' the microbial exposure and suppress allergic responses for months.

Between 2016 and 2026, respiratory allergy cases have skyrocketed in heavily affected nations. In the US, numbers rose from around 50 million to 65 million. China saw an increase from 150 million to 200 million, while India jumped from 100 million to 150 million. European countries like the UK and Germany also recorded rises of 20–30%.

The study's results open new clinical possibilities for preventing respiratory allergies. By targeting fibroblasts, researchers hope to develop long-lasting protection against allergic reactions in humans.

The findings suggest that controlled exposure to microbial fragments could train the lungs to resist allergies for extended periods. If translated into human treatments, this approach might help curb the rapid rise of respiratory allergies across the globe.