Professor, Program in Immunology
Clinical Research Division, Fred Hutch
Dr. Stan Riddell is a world leader in developing immunotherapies, which harness the power of the immune system to fight cancers and dangerous infections. His research focuses on detailing the complex biology of immune cells called T cells and pioneering therapies that use genetically reprogrammed T cells to specifically recognize and destroy diseased cells. These therapeutic T cells zero in on specific protein targets known as antigens, using either natural molecules called T-cell receptors or synthetic molecules called chimeric antigen receptors. Chimeric antigen receptors, also known as CARs, combine elements from T-cell receptors and from other immune cell-produced antibody molecules. His team’s breakthroughs are helping researchers make progress for patients who need better therapies.
University of Washington School of Medicine
Seattle Cancer Care Alliance
M.D., University of Manitoba, 1979
Resident, Internal Medicine, University of Manitoba, 1983
Fellow, Hematology, University of Manitoba, 1985
Dr. Riddell is an expert in using hematopoietic (blood-forming) stem cell transplantation (HCT) to treat patients with leukemias, lymphomas and other blood-related cancers, and in treating graft-versus-host disease (GVHD) that can occur when a donor’s immune T cells attack normal tissues as well as the malignancy. Based on his extensive clinical experience and laboratory investigations, Dr. Riddell has developed innovative therapies that use T cells to treat various viral infections and cancers. He was the principal investigator on the first human trial of transferred therapeutic T cells, to prevent dangerous cytomegalovirus infections after HCT, and on four subsequent clinical trials of ‘adoptive’ T cell therapy, including the first using leukemia-reactive T cells to treat relapsed leukemia post-transplant and the first using CAR-engineered T cells of defined subset composition.
Dr. Riddell’s early studies demonstrated the potential to augment T cell immunity by the adoptive transfer of antigen-specific T cells and uncovered mechanisms by which virally-infected cells evade immune recognition. These findings provided insights into similar mechanisms that tumors use to escape T cell immunity and that might be therapeutically targeted to improve patient outcomes. More recently, the Riddell team identified the subset of T cells that can best survive and function after transfer to patients and found that using clearly defined combinations of T-cell types can make the therapy even more effective. They have developed critical techniques for the isolation, expansion, genetic modification and reinfusion of therapeutic T cells, and for monitoring patient safety as well as T cell persistence, migration and function post-infusion. Many of these powerful methods are now broadly used in developing adoptive immunotherapies, including state-of-the-art ways to identify the tumor antigens recognized by T cells and to rapidly multiply the number of disease-fighting T cells.
Dr. Riddell’s research group continues to make new discoveries to enable the development of effective T cell therapies for more patients. They are:
—Dr. Stanley Riddell