Intruder alert

 

SMALL PRINT:YOUR BODY has a top-notch internal alarm system called the innate immune system – it can sense disease-causing intruders and trigger a response to get rid of them. But if this front-line defence kicks off against our own tissues, it could result in auto-immune disease.

That fine balance is the subject of The offensive side of immune defences, an RDS Irish Times lecture, in association with the Irish Society for Immunology, on May 19th.

Speaker Dr Kate Fitzgerald, who is to receive the 2011 Irish Society for Immunology Public Lecture Award, reckons innate immunity is the most exciting aspect of immunology.

“It is the body’s first line of defence. It is essential. Without it we would not be able to handle even the most innocuous microbes we would encounter,” she says.

Her lab at the University of Massachusetts looks at how our immune system discriminates between a disease-causing pathogen and something non-threatening, or even molecules from our own body.

Dr Fitzgerald, who studied at University College Cork and Trinity College Dublin, will talk about how being able to distinguish molecules means we can control infection, but the flip side is that if these same events are misregulated it can lead to diseases like arthritis or lupus.

“I would like people to understand how the immune system is a double-edged sword, where on the one hand it wards off infections, but it’s a fine balance and a slight tipping of the scale can have serious consequences,” she says.

“Control is everything.”

The event, which starts at 7pm at the RDS Merrion Room on Thursday May 19th, is free but places must be booked in advance – email science@rds.ie or call 01-2407289. See rds.ie/science

A right royal protein

WHAT MAKES a queen? If you are human, it can be down to having the appropriate royal parents, or perhaps marrying prince charming and waiting. And if all goes to plan tomorrow in London, Kate Middleton will be going for option number two. But in honeybees, the route to queendom is a little more biochemical, and a new study pinpoints a protein called royalactin as having an important role.

For honeybees, there are two female castes: the worker and the larger and longer-lived queen, points out Masaki Kamakura in Japan, whose study was published online in the journal Nature earlier this week. A larva becomes a queen when it is nourished by “royal jelly”, a substance that worker bees make – but quite how that happens has been unclear, according to Kamakura.

He found that royal jelly lost its potency for making queens if it was stored at high temperatures for a month. So he looked to see what proteins were being lost under these conditions, and that search led him to royalactin.

Kamakura then fed the royalactin protein, along with some other nutrients, to honeybee larvae and saw it indeed had a queen-making effect.

And when he fed the protein to fruit fly larvae, it beefed up the flies and induced several biochemical changes, giving some clues about how the process might work.

In the journal paper he describes the royalactin protein as “the major active factor in the induction of caste differentiation by royal jelly”.

But others point out there’s more at play. Nature’s Great Beyond blog quotes Canberra-based researcher Ryszard Maleszka, who comments: “There are dozens of potentially important components in royal jelly and giving a special rank to one of them is misleading.”

Claire O’Connell