September 29, 2010

Gut-Invading Worms

(Ivanhoe Newswire) -- What did the intestinal worm say to the human body when the regulatory T cell-inducing pathway was blocked?  It was nice gnawing you.  But are these gut-invading worms all bad news?  A recent study shows how intestinal worms sidestep the immune system by inducing the development of suppressive T cells and suppress allergic responses.

Immune T cells are essential for the clearance of invading microbes -- including the renowned intestinal worm -- but flipping the switch off on the immune system is essential for avoiding collateral tissue destruction.  The job goes undone in part to a population of suppressive T cells called regulatory T (T reg) cells. Rick Maizels of the University of Edinburgh and his team of bookworms show that gut-invading worms produce protein that generates T reg cells in mice; in this way, the worms make possible their own survival.  It's like famous joke in the beginning of the article (maybe not famous, but clever nonetheless), when the T reg-inducing pathway becomes blocked, the worms pack their bags and head for the big apple.

T reg cells allow these intestinal enemies to worm their way into the gut, but it's not as detrimental as you would think (as bad as say . . . global worming).  These cells suppress allergic responses, which may explain why humans infected with intestinal worms tend to suffer less from allergies.  These worms might now glow, but they are shining light on the issue of avoiding collateral tissue destruction.

SOURCE: Journal of Experimental Medicine, September 2010