India, Oct. 7 -- Our immune system is so powerful that it can sometimes attack parts of our body itself, leading to autoimmune disorders. Today, it is well known that the body has a regulatory mechanism, called peripheral immune tolerance, that prevents the immune system from going overboard, but it took a long journey spanning decades before scientists deciphered how that works.

The Nobel Prize for Medicine, announced on Monday, honours three scientists who made pioneering discoveries along that journey. Shimon Shakaguchi, currently with Osaka University, discovered regulatory T cells, the watchdogs that help prevent the immune system from attacking the body. Independently, Mary E Brunkow (Institute for Systems Biology, Seattle) and Fre...