Americans win Nobel prize in medicine for work on human immune system​Americans win Nobel prize in medicine for work on human immune system 

 A trio of scientists — two of them American and one Japanese — have won the Nobel Prize in Medicine for their discoveries concerning peripheral immune tolerance, a mechanism by which the body helps prevent itself from attacking its own tissues instead of foreign invaders  ​​A trio of scientists — two of them American and one Japanese — have won the Nobel Prize in Medicine for their discoveries concerning peripheral immune tolerance, a mechanism by which the body helps prevent itself from attacking its own tissues instead of foreign invaders