Peptide 26: It could be the key to you getting your summers back

Asthma UK-funded scientists have uncovered vital information about the body's response to pollen, which could lead to the creation of effective new pollen vaccines.

Using cutting edge technology, they've identified the part of grass pollen grains that're detected by the body’s immune system, activating an allergic reaction in those who’re susceptible.

Over 15 million people in the UK suffer from hay fever caused by grass pollen, and five million people experience symptoms that severely impact on their quality of life. At least half of people with asthma also have hay fever, and this can make their asthma symptoms much worse, putting them at risk of a life-threatening asthma attack and severely limiting their day-to-day activities.

In allergic asthma, inflammation in the lung is caused by a type of white blood cell called the CD4 T-cell that mistakenly attacks harmless allergens, like pollen. This causes an unnecessary immune reaction that damages the body’s tissues. The only treatment options currently available are to avoid the allergen, which can be extremely difficult during pollen season, or to switch off the inflammatory response with medicines or a vaccine. Allergen immunotherapy is currently the closest thing to a cure for allergies, but we don’t yet know how effective or safe immunotherapy is in the long-term - or how to maintain its effects.

Dr Stephen Till, Dr Rosemary Boyton and colleagues at the MRC-Asthma UK Centre in Allergic Mechanisms of Asthma are working on creating a new vaccine that'll 're-educate' a person's immune system so that it no longer responds to pollen.

Dr Stephen Till, now based at King's College London, explains:

"Part of the problem in developing new treatments is that we need to understand how the immune system recognises and responds to pollen grains. This has been difficult in the past because although CD4 T-cells can vary greatly, this is necessary to help them recognise and defend against bacteria and viruses. However, this also means that identifying those specific CD4 T-cells which recognise allergen amongst all CD4-T cells is like finding a needle in a haystack."

Working with a research team at the Benaroya Institute in Seattle, the scientists used a new research tool enabling them to separate out the pollen-specific CD4 T-cells from other CD4 T-cells in people with grass pollen allergy. This tool, called a tetramer, is created from a small fragment of pollen protein fused to a light-emitting chemical. The researchers used the tetramers to count and sort the pollen-specific CD4 T-cells using a light-detecting machine called a flow cytometer. 

Dr Rosemary Boytonat Imperial College London added, "We discovered the part of the pollen that’s most commonly recognised by the immune system, called peptide 26 (p26). We’ve started to delineate the biological pathway through which dampening down of the allergic response can be achieved."

The scientists found that not only is p26 found in Timothy grass, a common allergy trigger often studied by scientists, but also in a number of different pollen grains such as rye and velvet grass.

"We found that p26 immune recognition applies across a wide range of human genetic diversity, meaning that going forward, it may be possible to develop a vaccine that not only protects against a wide range of grass allergens but can also be used in a large section of the population."  says Dr Boyton.

The research has been published in the high impact journal Thorax.

Leanne Reynolds, Research Operations Manager at Asthma UK commented:

"Allergen immunotherapy is currently quite a specialised treatment which isn’t suitable for everyone. There’re also safety implications involved, which is one of the reasons why it isn’t more widely available in the UK. This research takes us a step closer to developing a more effective, safe vaccine that could potentially cure allergic asthma in the future."

(Original article)

Previous Stories