The discovery of a molecule which appears to play a key role in allergies may lead to new therapies, experts say.
Allergies have trebled in 20 years
The researchers from Barts and the London School of Medicine managed to stop allergic attacks in mice by targeting the molecule, P110delta.
They say it may offer the chance to prevent allergies, not just relieve symptoms.
The Journal of Immunology reported that the method did not interfere with the rest of the body's immune defences.
Allergies happen when part of the immune system identifies something common and harmless, such as pollen or house mite faeces, as a foreign invader, and launches an attack.
Unfortunately, this can cause inflammation on the skin, in the nose or airways, which creates the unpleasant and sometimes dangerous symptoms reported by sufferers.
Most anti-allergy pills can reduce the symptoms, but scientists cannot shut down the process itself without damping down the entire immune system, and making the person vulnerable to genuine threats such as infection.
So they are looking in more detail at the chain reaction of an allergy attack, looking for new ways to target the causes more precisely.
The London-based team were looking at a family of proteins called PI3Ks, which have a variety of roles around the body. The P110delta molecule is one of these.
They now believe that targeting this alone might be able to interfere with attacks.
In mice, the molecule could be blocked, without harming the rest of the immune system.
Dr Khaled Ali, who led the project, said: "This work shows that we have the potential to take control of the body's reaction to an allergen and prevent symptoms from occurring."
Professor Bart Vanhaesebroeck, also from Barts and the London, said: "This work confirms our previous findings and shows once and for all that in an allergic reaction, it is P110delta that is the key player.
"We are very hopeful that a drug for human patients can be developed in the very near future."