How our immune system kills abnormal blood cells

A team of researchers at the IRCM, led by Dr. André Veillette, an adjunct professor at McGill University in the Faculty of Medicine explains how our immune system kills abnormal blood cells. Their discovery, recently published in the Journal of Experimental Medicine , could eventually lead to new treatment avenues for leukemia, lymphoma and certain types of infectious viral diseases. "Our team is studying how natural killer cells can eliminate abnormal hematopoietic (blood) cells," explains Dr. Veillette, Director of the Molecular Oncology research unit at the IRCM. "NK (natural killer) cells are crucial to the immune system and play a critical role in protecting us against viruses and cancer cells." In a previous study, the IRCM researchers found the SAP molecule to be an essential component of NK cells' ability to kill abnormal blood cells, which can be found in blood cancers such as leukemia and lymphoma, as well as in certain infectious viral diseases like infectious mononucleosis. "In addition to SAP, a protein called EAT-2 can also be found in NK cells," adds Dr. Veillette. "We knew that EAT-2 cooperates with SAP, and, with this research project, we wanted to better understand why they are both required for the proper functioning of NK cells." Using a variety of genetic, biochemical and imaging approaches, the researchers successfully defined the molecular and cellular mechanisms by which EAT-2 controls the activation of NK cells. "We identified the molecular chain of events that occur, and showed that EAT-2 and SAP perform different functions using distinct mechanisms," says Dr. Veillette.