Niels K. Jerne was born in England in1911 but mainly worked in Switzerland. He was awarded the Nobel Prize in 1984 for his theoretical studies on the immune system. He is credited with the concept that the thymus is the site where lymphocytes multiply differentiate and become functional T cells. He developed the network theory that antibodies stimulate antiidiotypes and with antibodies form a functional network. He also was the first to expound the selective theory that explained how antibodies could be produced that respond to a great variety of antigens

Tizard Introduction to Immunology 4th Ed p 334