Gene Therapy Could Offer Long-Lasting Allergy Relief

Modifying blood stem cells could turn off the immune response to an allergen.

Allergies can be lifelong or they can resolve seemingly out of nowhere, and patients can develop them at different points during their life; however, this process remains largely unknown.

Most patients are advised to refrain from interacting with their allergen, but this may be difficult for patients with severe allergic asthma.

In a new study published by JCI Insight, investigators were able to turn off the immune response that results in an allergic reaction in animal models.

"When someone has an allergy or asthma flare-up, the symptoms they experience results from immune cells reacting to protein in the allergen," said lead researcher Ray Steptoe, PhD. "The challenge in asthma and allergies is that these immune cells, known as T cells, develop a form of immune 'memory' and become very resistant to treatments.”

While T cells are very beneficial when responding to harmful pathogens, they can elicit a dangerous response to certain allergens that may not require such action. For some patients, emergency epinephrine treatment can prevent a life-threatening allergic reaction.

In the current study, the authors were able to desensitize the immune system to a particular asthma allergen.

"We have now been able 'wipe' the memory of these T-cells in animals with gene therapy, de-sensitising the immune system so that it tolerates the protein,” Dr Steptoe said. "Our work used an experimental asthma allergen, but this research could be applied to treat those who have severe allergies to peanuts, bee venom, shell fish, and other substances."

To achieve this, the authors took blood stem cells and inserted a gene that regulates the allergen. Next, the cells were transplanted into the patient.

The transplanted blood stem cells were observed to create new cells that express the protein and target immune cells, thus turning off the immune response, according to the study.

The authors said that the end goal would be a single gene therapy via injection that could replace short-term treatments, which only target symptoms.

"We haven't quite got it to the point where it's as simple as getting a flu jab (sic), so we are working on making it simpler and safer so it could be used across a wide cross-section of affected individuals," Dr Steptoe said. "At the moment, the target population might be those individuals who have severe asthma or potentially lethal food allergies."

The authors said that further studies are needed in human cells in a laboratory setting. These findings could have implications for the millions of individuals around the world with asthma.

"Even though there are effective treatments available for the vast majority, patients face a number of obstacles and challenges in their self-management practices," said Peter Anderson, PhD, chief executive officer at Asthma Foundation of Queensland and New South Wales.