Across the Atlantic, Dr. Cooper, then a pediatrician at the University of Minnesota and now a professor at the Emory University School of Medicine, had noticed that some inherited immune disorders in children seemed to affect two separate pathways of the immune system. His attention was drawn to studies in chickens that pointed to a possible explanation.

Chickens have a thymus and an additional lymphoid organ called the bursa of Fabricius. Dr. Cooper discovered that in newly hatched chickens, lymphocytes are generated in the liver and bone marrow, while some mature in the thymus and other lymphocytes mature in the bursa. In mammals, these B cells simply reside in the bone marrow and they were the ones that spit out antibodies when activated by T cells. There wasn’t just one set of immune cells that carried out all disease-fighting tasks in the body, but rather two types of lymphocytes with separate jobs.

“These studies told us that almost everything we were thinking about in immunology had to be revised,” Dr. Cooper said. This finding set the stage for several other important discoveries regarding immune deficiencies, treating autoimmune disorders and developing new cancer therapies.

Dr. H. Michael Shepard, Dr. Axel Ullrich and Dr. Dennis J. Slamon

The combined efforts of Dr. H. Michael Shepard and Dr. Axel Ullrich, who were at Genentech when they did their research, and Dr. Dennis J. Slamon, an oncologist at the University of California, Los Angeles, resulted in the creation of Herceptin, the first monoclonal antibody therapy for breast cancer. They are the recipients of the Lasker-DeBakey Clinical Medical Research Award.

Monoclonal antibodies are proteins produced by B cells that bind to specific invader organisms and abnormal cells. They help the immune system identify and remove abnormal cells, including cancerous ones. In the case of Herceptin, the antibody binds to a protein called HER2 on the surface of breast cancer cells.