An important breakthrough in immunology by IRCM researchers

A team of researchers at the IRCM led by Dr. André Veillette made an important breakthrough in the field of immunology, which will be published online today by the scientific journal Immunity. The scientists explained a poorly understood molecular mechanism associated with a human immune disorder known as XLP disease or Duncan's syndrome.

"We studied the SAP molecule, which plays a critical role in multiple different types of immune cells," says Dr. Veillette, Director of the Molecular Oncology research unit at the IRCM. "More specifically, we wanted to understand why SAP is an essential component of natural killer cells' ability to eliminate abnormal blood cells."

Natural killer (NK) cells are crucial to the immune system, and provide rapid responses against cancer and virus-infected cells, especially blood cells as can be found in leukemia and lymphomas. Patients with XLP are at a high risk of developing lymphomas.

"Until now, the way by which SAP enhances NK cells' response to abnormal blood cells was not well understood," explains Zhongjun Dong, former researcher in Dr. Veillette's laboratory and first author of the article. "We discovered that SAP stimulates the function of NK cells through a double mechanism. On one hand, it couples the necessary genes and enzymes to increase NK cell responses, and on the other hand, it prevents genes from inhibiting these responses." Dr. Dong is now a professor at Tsinghua University, a leading university in China.

"The SAP molecule is important in immunity, as it is associated with most cases of XLP disease," adds Dr. Veillette. "In addition, our findings may have implications on the role of SAP in other diseases such as lupus and arthritis."

According to the XLP Research Trust, X-linked lymphoproliferative disease (XLP), also known as Duncan's syndrome, is a fatal disease affecting boys worldwide. The cause of the condition was only found in 1998, so many cases may not yet have been properly diagnosed. If untreated, approximately 70% of patients with XLP die by the age of 10.

Dr. Veillette's research is funded by the Canada Research Chairs program and the Canadian Institutes for Health Research (CIHR). "I applaud Dr. Veillette and his team for their research in the field of human immune disorder and their breakthrough discovery in understanding the role of the SAP protein in controlling abnormal blood cells," said Dr. Marc Ouellette, Scientific Director of the CIHR Institute of Infection and Immunity. "Their work will contribute to a better understanding of our immune system and how to treat human immune diseases for improved health for all Canadians."

For more information on this discovery, please refer to the article summary published online by Immunity: http://www.cell.com/immunity/abstract/S1074-7613(12)00231-2.

André Veillette obtained his medical degree from the Université Laval. He is Full IRCM Research Professor and Director of the Molecular Oncology research unit. Dr. Veillette is a full researcher-professor in the Department of Medicine (accreditation in molecular biology) at the Université de Montréal. He is also adjunct professor in the Department of Medicine (Division of Experimental Medicine) at McGill University. Dr. Veillette holds the Canada Research Chair in Immune System Signalling. For more information, visit www.ircm.qc.ca/veillette.

Founded in 1967, the IRCM is currently comprised of 36 research units in various fields, namely immunity and viral infections, cardiovascular and metabolic diseases, cancer, neurobiology and development, systems biology and medicinal chemistry. It also houses three specialized research clinics, seven core facilities and three research platforms with state-of-the-art equipment. The IRCM employs 425 people and is an independent institution affiliated with the Université de Montréal. The IRCM clinic is associated to the Centre hospitalier de l'Université de Montréal (CHUM). The IRCM also maintains a long-standing association with McGill University.

The Canadian Institutes of Health Research is the Government of Canada's health research investment agency. CIHR's mission is to create new scientific knowledge and to enable its translation into improved health, more effective health services and products, and a strengthened Canadian health care system. Composed of 13 Institutes, CIHR provides leadership and support to more than 14,100 health researchers and trainees across Canada.