Scope 43 - TB Vaccine reveals new approach to treating Asthma

15 October 2010, Asthma

While establishing his asthma research programme at the Malaghan Institute in the mid-1990s, Prof Graham Le Gros observed that certain types of bacterial lung infections could actually halt the development of asthma in mice. This pivotal discovery made the front cover of the prestigious New Scientist magazine and has led to a new form of therapy that could revolutionise the way we treat asthma.

For parents of children who suffer repeated severe asthma attacks, life is a daily battle. Asthma is the consequence of an overactive immune system, causing inflammation in the lungs. The steroid inhalers that are used to treat the disease work by reducing the inflammation in the lung so it is easier to breathe. However, there is growing concern regarding their long-term use.
It has been proposed that the recent increased prevalence and severity of asthma, particularly amongst children, is a consequence of the Western world's obsession with cleanliness. The so-called ‘Hygiene Hypothesis' suggests that some people react to harmless environmental stimulants such as pollen or house dust mites because as infants they were not exposed to the infections required to fully develop their immune systems.

Prof Le Gros' research group decided to test this hypothesis by looking to see if they could restore ‘immune balance' in experimental asthma models with controlled bacterial infections. Strikingly their research showed that treatment with the bacteria used to make the TB vaccine, actually prevented the inflammatory immune responses normally associated with asthmatic lungs. This research revealed a new way of potentially treating asthma - by simply giving the immune system something else to focus on!

Prof Le Gros' published scientific paper describing this landmark discovery has been extensively cited and used by scientists, clinicians and drug companies to identify safer versions of the bacteria and their extracts for the development of a vaccine to treat asthma in humans. There are now several new compounds being developed in the USA that are in the late stages of clinical trial and the FDA approval process - a wonderful testament to the original pioneering research undertaken by Prof Le Gros' research group here at the Malaghan Institute.