Nobel Prize in Medicine, 2011

The Nobel Prize in Physiology or Medicine 2011 was divided, one half jointly to Bruce A. Beutler and Jules A. Hoffmann "for their discoveries concerning the activation of innate immunity" and the other half to Ralph M. Steinman "for his discovery of the dendritic cell and its role in adaptive immunity".

Mr. Beutler and Mr. Hoffmann were cited for their discoveries in the 1990s of receptor proteins that can recognise bacteria and other microorganisms as they enter the body, and activate the first line of defence in the immune system, known as innate immunity.

Mr. Steinman, 70, was honoured for the discovery of dendritic cells ,which help regulate adaptive immunity, the next stage of the immune system’s response, when the invading microorganisms are purged from the body.The dendritic cells activate so called T-cells .Those cells have a key role in adaptive immunity, producing antibodies that destroy infections. Once the infection has been stopped, the immune system maintains a memory that helps it mobilise its defences next time it comes under a similar attack.