Allergy - it's in the genes

May 28 2008

In a world first scientists at the Westmead Millennium Institute 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 Institute of Immunology and Allergy* which investigated the 'PHF11' gene and its role in the immune system - and therefore allergies - by focussing 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 eczma."

* The Institute of Immunology and Allergy is within the Westmead Millennium Institute.

Explanatory note from Dr Graham Jones

It is well known that allergy has a strong genetic basis: in other words, if parents have an allergy then in many cases so to do their children. Although genetic studies can show what genes play a role in allergic diseases such as asthma and eczema, understanding how these genes contribute to the development of allergic disease often lags behind.

This new work is particularly exciting as it builds upon genetic studies to show for the first time how a gene called PHF11 is involved in allergic disorders such as asthma and eczema, says Dr Jones.

Notes

• Over 2 million Australians are living with asthma, many of whom are young people aged between 15-24 years. The gene, called PHF11, was first identified in genetic association studies of families with asthma, and confirmed by the Westmead group in children with severe eczema.
• The results of this two-year NHMRC-funded study are reported in the May edition of the internationally prestigious 'Journal of Allergy and Clinical Immunology'.