A team of British scientists, headed by Dr Claudio Nicoletti, at the Institute of Food Research team in Norwich believe they have identified a key molecule responsible for food allergies. The molecule Interleukin-12 (IL-12) was found to be absent in mice bred to be allergic to peanuts.

IL-12 is normally produced by dendritic cells, part of the body's immune system and has a role in control of Immunoglobulin E (IgE) release.  The team compared the activity of dendritoc cells in the gut and spleen of allergic and allergy resistant mice and found that dendritic cells in the gut of the allergic mice had stopped producing the IL-12, leading to an over-production of IgE. 

When IL-12 production was shut off, an imbalance occurred between two groups of T cells: Th1 which is important in pathogen resistance, and Th2 which stimulates antibody production. 

"We have identified the missing molecule that normally keeps immune responses under control and appropriate," Dr Nicoletti said."We now have a target for a potential treatment for food allergy.

"Further research will tell us whether giving peanuts together with IL-12 to a person with an allergy might re-establish a normal immune response to peanuts, potentially curing their allergy."

Journal of Allergy and Clinical Immunology (2007 in press).