STOCKHOLM (AP) — Three scientists won the Nobel Prize in medicine Monday for discoveries about how the immune system knows to attack germs and not our own bodies. The work by Mary E. Brunkow, Fred Ramsdell and Dr. Shimon Sakaguchi uncovered a key pathway the body uses to keep the immune system in check, called peripheral immune tolerance. Experts called the findings critical to understanding autoimmune diseases such as Type 1 diabetes, rheumatoid arthritis and lupus. In separate projects the...