The good vs the bad in immunology

Professor Barbara Fazekas de St Groth

Professor Barbara Fazekas de St Groth, Group Head of T Cell Biology

Since she first learned about immune diseases in medical school, Barbara Fazekas de St Groth has wanted to know how the immune system works. She admits that it’s a mammoth goal because our current understanding of the immune system is pretty basic.

In the 1800s, many autoimmune and allergic diseases, like hayfever, were either unheard of or rare. The sharp increase in prevalence has largely been attributed to factors found in the Western World such as diet, environment and exposure to chemicals.

Barbara says that if you live in a village in Pakistan, you are unlikely to have many of the diseases that plague the developed world. But if you emigrate, your children born in the West will lose that resistance.

So what is it about our lifestyles that makes our immune systems hyper-reactive?

Barbara leads the T Cell Biology team and they are investigating the threshold at which the immune system becomes activated. If the threshold is too low, the body overreacts to harmless substances or attacks itself and we develop an allergic reaction or an autoimmune disease.

She says that one of the problems with our obsession with germs is that when we use antibacterial wash we actually remove the good bacteria that live on our skin as well as the bad. She uses the example of children in day care centres who generally have a lower incidence of allergies because, as they play, they not only swap the bad guys that cause things like coughs and colds, but they actually swap good germs that keep the threshold at the right level.

Her latest research, published recently in Proceedings of the National Academy of Sciences (PNAS), showed that the immune cells in the outer layer of the skin constantly act as peacekeepers to stop the immune system killing off the good germs.

This research is important because it showed that the skin can differentiate between the good bacteria and the harmful bacteria. If we could mimic what the “good guys” do, then we could develop treatments that stop allergies and autoimmune reactions in their tracks.

Imagine if we could give babies the good bugs they need instead of, as adults, consuming drugs to dampen our response to pollen or peanuts?