Philippa Marrack, PhD

Working in the labs at National Jewish Health in Denver, Marrack and her husband and fellow researcher, John Kappler, were among the first in the world to isolate the T-cell receptor, a crucial component of the immune response that identifies foreign invaders inside the body and destroys them. As a direct result of this research, Marrack discovered how the T-cells that could target the body’s own tissues are destroyed in the thymus before they can cause problems. It’s when rogue cells are not destroyed that they cause destructive autoimmune diseases like AIDS, diabetes, MS, and lupus. Marrack and Kappler also discovered superantigens, powerful toxins that stimulate large numbers of T-cells and can cause devastating immune responses and violent symptoms such as those seen in toxic shock syndrome or food poisoning. Marrack’s current research projects center on why certain autoimmune diseases, like lupus and MS, are more prevalent in women than in men.

Born in England, Marrack earned her doctorate of philosophy degree in biological sciences at Cambridge University. She came to the United States for postdoctoral research and met her lifelong scientific partner and husband, John Kappler. They joined the faculties at National Jewish Health and the University of Colorado Health Sciences Center in 1979.

During her career, Marrack has published more than 300 peer-reviewed journal articles, her latest in 2009 in the science journal Nature. As ranked by citations and the impact of printed journal articles, she is the third most influential researcher in the nation and the top female researcher. She has been a member of the U.S. National Academy of Sciences since 1989 and a fellow of the Royal Society in Great Britain since 1997. Marrack was elected to the prestigious international Institute of Medicine in 2008.