GATA-3 Blocks Regulatory T-Cells,Leading to Allergies

[Guest guest]

[Regulatory T Cells are over expressed in CLL. These cells suppress

the immune system, so over expression may be involved in CLL progression.]

Fight against hay fever and other allergies helped by new immune

system discovery

A mechanism which can lead to hay fever and other allergic reactions,

by preventing the immune system from regulating itself properly, has

been discovered by scientists. Researchers hope their finding,

published today (Thursday 27 December 2007) in the journal PLoS

Biology, will allow therapies to be developed that treat allergies by

stopping this mechanism.

The new research shows that a gene known as GATA-3 can block the

development of regulatory T-cells in the immune system by locking

another gene. This gene, FOXP3, is key to regulatory T cells and when

it is blocked new regulatory T cells stop being produced.

The scientists, from Imperial College London, the Swiss Institute of

Allergy and Asthma Research in Davos, Switzerland, and other

international institutions, hope that if they can develop therapies to

stop FOXP3 being blocked, they can ensure that regulatory T cells are

free to work normally.

Regulatory T cells are believed to be vital for averting allergic

reactions in healthy individuals because they keep the other cells in

check, suppressing pro-allergic cells known as Th2 cells and stopping

the immune system from needlessly attacking the body.

In people with allergies, some types of cells in the immune system,

particularly the Th2 cells, wrongly identify a particular allergen,

such as pollen, as being dangerous. Whenever the person encounters

this allergen again, these cells promote the production of antibodies

to attack it, causing an allergic reaction.

Dr Carsten Schmidt-Weber, the principal investigator on the research

from the National Heart and Lung Institute at Imperial College London,

said: & #8220;This finding will help us to understand how healthy individuals

are able to tolerate allergens and what we need to do to re-induce

tolerance in the immune systems of patients with allergies. We hope

that we will soon be able to help not only patients suffering from

single allergies, but also those with multiple ones - the atopic

patients. & #8221;

The researchers reached their conclusions by analysing the genes

related to regulatory T-cells and analysing how they interacted. They

confirmed their findings by using mouse models to show that mice which

were genetically engineered to express the GATA-3 gene in all T cells

showed dramatic defects in the production of regulatory T-cells.

Dr Schmidt-Weber and his colleague Professor Durham, also from

the National Heart and Lung Institute at Imperial College, hope the

new findings will eventually lead to new, more effective treatments

for hayfever and other allergies, to be used in combination with

existing immunotherapies. They hope such treatments could help prevent

hay fever and allergic asthma from reaching epidemic proportions.

[Guest guest]

I have often wondered why my hay fever allergies went

away as my CLL got worse. My allergies to many drugs

is no better though. It seems that research is in the

right direction. Probably too late to help me though.