IRIC - Institute for Research in Immunology and Cancer

Published on October 14, 2011

IRIC researchers show how to increase the immune system’s efficiency

IRIC researchers have taken another major step in the development of anti-cancer immunotherapies.  Published in the scientific journal Molecular Systems Biology, a recent study directed by Principal Investigators Pierre Thibault and Claude Perreault shows, for the first time, that our cells display messages on their surface that give the immune system an overview of their global physiological condition. A better understanding of the messages generated will allow investigators to make the immune system more efficient in recognizing cancer cells. Immunotherapy is a type of treatment that tries to stimulate the immune system to respond better to diseases and infections. In treating cancer, the goal of immunotherapy is to induce the immune system to destroy the cancer cells.

For this study, IRIC researchers developed a new approach of unequalled sensitivity, allowing for the detection of thousands of protein fragments (peptides) presented to the immune system on the surface of the cells. The immunopeptidome is the name given to the complete range of these fragments displayed by the cells, and which play an essential role in our survival. The immune system does not attack cells that show a normal immunopeptidome.
The cutting-edge approach developed in this study allowed comparison of the immunopeptidome of normal cells with that of abnormal cells. It was possible to show that the changes in the immunopeptidome reflected specific disturbances within the cells, thus offering the immune system an open window on the abnormal physiological status of these cells. This better understanding of the processes determining the composition of the immunopeptidome would make it possible to predict the changes in its composition and would be a major advantage for the development of anti-cancer immunotherapies.

These experimental and therapeutic approaches result directly from the discoveries made by Dr. Ralph M. Steinman, who won the 2011 Nobel Prize for Medicine or Physiology. Dr. Steinman was convinced of the value of these immunotherapeutic approaches, to the extent that he personally underwent experimental treatments for pancreatic cancer, to which he succumbed to last September 30.

Paper cited Caron E, Vincent K, Fortier MH, Laverdure JP, Bramoullé A, Hardy MP, Voisin G, Roux PP, Lemieux S, Thibault P, Perreault C. (2011). The MHC I immunopeptidome conveys to the cell surface an integrative view of cellular regulation. Mol Syst Biol. 7:533.