Seeking immunity from the ill effects of obesity

Research Lives: Dr Andrew Hogan, principal investigator with the Metabolic Immunology Research Group, Maynooth University

Your research looks at the links between obesity and the immune system and metabolism in children. Why?

“We know that obesity in adults is linked with more than 200 different diseases. Research tells us that in obesity the immune system becomes overactivated, which damages tissues in the body, and some immune cells become depleted so they can’t protect properly. I want to see how we can protect children living with obesity from these immune system changes, to protect them against future disease and damage.

How did you get into this area of research?

I am the first person in my family to go to university. I went to Maynooth University through the access programme, then after my PhD I worked as a Newman scholar with Donal O'Shea and Lydia Lynch in University College Dublin.


We were interested in a type of cell in the immune system called the invariant natural killer T-cell. It attacks viruses and tumours, but stops working properly in obesity. When I moved back to Maynooth to set up my own research group, I thought it would be interesting to look at immune changes in younger people living with obesity.

What did you find when you looked at children with obesity?

We did a project with the National Children’s Research Centre, where we worked with children living with obesity at age six, 10 and 16. We could see kids as young as six were starting to show signs of chronic inflammation, a type of immune-system overactivation.

They already had molecular markers of it in their bloodstream. I thought maybe if we can intervene with children who are living with obesity and stop this immune activation, turn down the chronic inflammation, we could perhaps delay or reduce related disease in adulthood.

We are looking at options there, using a gut hormone that is known to tone down chronic inflammation. There is a shorter-term outlook too: in another project we are looking at obesity and vaccinations.

Tell us more about that.

We know that some vaccines are less effective in adults with obesity, which makes sense. After all, we have been showing for 15 years that in obesity the immune system is overactivated or exhausted.

So we looked at the responses to childhood measles and rubella vaccinations, and in a small study we found that children with obesity have far less of the antibody titre after vaccinations, which means they may not be as well protected from these diseases. Now we are looking at this more closely in larger numbers of children, and we hope to examine responses to the HPV vaccine too.

What do you love about your work?

I just really enjoy it. Of course there are times when things don’t work out as you expect, but I’m a sunny-side-up kind of person, and you just rethink the experiment or find a new direction.

What do you do to take a break?

I find that exercise is a great way to clear the mind. When I was a teenager I did a lot of kickboxing, I was number one in the world at one point. In the last few years I have been doing CrossFit, and I was involved in opening a gym where I teach classes. It’s one of those things that, no matter how you feel at the start of the class, you will always be happy about having done it afterwards. It’s a great way to unwind.

Claire O'Connell

Claire O'Connell

Claire O'Connell is a contributor to The Irish Times who writes about health, science and innovation