A Korean research team found that the p300 protein, which regulates immune responses, is key to treating allergic asthma.

The joint research team, led by Professor Sohn Myung-hyun of Severance Hospital’s Allergy and Asthma Center and Professor Yoon Ho-geun of Yonsei University College of Medicine, announced Monday that the p300 protein triggers a regulatory T-cell response, reducing allergic-asthma severity.

Allergic asthma occurs when the body mounts an excessive immune response to external substances.

According to the research team, the p300 protein regulates GBP5-gene expression, strengthening the function of regulatory T cells -- which prevent excessive immune responses -- and maintaining this balance.

The team reached this conclusion using a mouse model of allergic asthma that lacked the p300 protein.

In this mouse model, they observed not only a reduced number of regulatory T cells but also diminished immune-suppressive function. Additionally, they noted excessive activation of helper T cells -- which assist other cells’ immune functions -- leading to airway inflammation.

To examine this process more closely, the team conducted chromatin immunoprecipitation (ChIP) and RNA-sequencing analyses. ChIP was used to determine which cell-activation processes p300 is involved in, while RNA sequencing identified which proteins were elevated in the affected cells.

The results showed that p300 influences GBP5-gene expression, which supports immune responses to viruses and bacteria. This, in turn, affects T-cell proliferation, suppression, and maintenance.

“This study confirmed that p300 affects GBP5-gene expression and regulatory T-cell growth. This helps suppress asthma exacerbation,” Professor Sohn said. “It suggests a direction for developing allergic-asthma treatments that target p300.”

The team published their findings in the latest issue of the American Journal of Respiratory and Critical Care Medicine.