28/05/2008

Scientists identify gene associated with allergies

In a world first, scientists have identified how a gene associated with allergic diseases such as asthma and eczema works, providing new hope for potential drug treatments.

The University of Sydney's Dr Graham Jones led a group based at the Westmead Millennium Institute (Institute of Immunology and Allergy) which investigated the 'PHF11' gene and its role in the immune system (and therefore allergies). They focused on two types of T-cells known as Th1 and Th2.

"One of the hallmarks of allergy is an imbalance between these two types of T-cells: we know many children and adults with allergies have an oversupply of the Th2 version of T-cells compared to the Th1 version," says Dr Jones.

"Our breakthrough is finding that the PHF11 gene encodes a protein whose function is to turn on other T-cell genes and, more importantly, that its effect is more pronounced in Th1 than Th2 cells.

"In a nice tie-in with our earlier genetic studies, we have also found that genetic variants in the PHF11 gene that are associated with childhood eczema lead to lower levels of PHF11 gene activity. This could lead to problems with Th1 T-cells.

"Although there is much work ahead of us, our results suggest that problems with the Th1 subset could contribute to the Th1/Th2 T-cell balance. This idea has been around for some time now, but it is very satisfying to uncover new evidence for it using our genetic and functional approach," states Dr Jones

"Most people with asthma or eczema are atopic - meaning they have a genetic tendency for the disorders," says Professor Tony Cunningham, Westmead Millennium Institute Director. "So this is an important step forward in this field of genetic research."

"While in its early stages the research does have the potential to guide the development of new drugs and topical therapies for the treatment of allergies like asthma and eczema."