Claude Perreault and his team are studying the cells that regulate the immune system, known as “T lymphocytes,” in order to understand and improve how the immune system works. Their research aims, among other things, to create a vaccine against cancer and prevent the aging of the immune system.

Research theme

Immunology is of considerable medical importance, since the ability of immune cells to distinguish between self and non-self is essential to life and is involved in 90% of fatal human diseases. Indeed, i) recognition of non-self is essential for the elimination of microbes and cancer cells; ii) immune responses against self-antigens cause autoimmune diseases and contribute to chronic inflammatory diseases, age-related neuronal decline, hypertension, and atherosclerosis. Dr. Claude Perreault is trying to discover why the thymus is the only organ capable of supporting T-cell development and how T cells learn to distinguish self from non-self in the thymus. Ultimately, he seeks to understand how T cells can recognize cancer cells and how to increase their anti-tumor activity.

Research objectives

1) Understanding the biology of the thymus.

The thymus is unique in at least two respects. It ages faster than any other organ and is the only organ capable of producing functional T lymphocytes. The Perreault team’s work has shown that premature aging of the thymus is due to intense proteotoxic stress. They have also shown that the KLF4 protein could be used to rejuvenate the thymus. To better understand what makes the thymus so special, the Perreault and Thibault teams are currently conducting mass spectrometry studies on different populations of thymic epithelial cells.

2) Develop a vaccine against cancer

Cancer is caused by genetic and epigenetic abnormalities that often lead to the production of abnormal proteins that can be detected by T lymphocytes. This recognition by T lymphocytes can trigger an immune response leading to the rejection of cancer cells. It is also known that the more T lymphocytes a tumor contains, the more favorable the prognosis for the patient.

For several types of cancer, exploratory work has shown that tumor regression can be observed after the injection of a “non-specific” stimulant (i.e., not directed against a particular molecule). While regression is most often partial, complete remission is sometimes observed. This requires that “foreign” molecules, called “cancer-specific antigens” (CSAs), first be recognized by immune cells (T lymphocytes), which then eliminate the cancer cells.

Research conducted by Dr. Perreault’s laboratory and his collaborators has led to the development of an approach combining genomics, bioinformatics, and proteomics, through which they have identified the largest repertoire of human CSAs. This work has also highlighted the key factors that can influence the ability of these antigens to induce strong anti-tumor responses and paves the way for the development of a vaccine against various cancers. A first vaccine containing ACSs discovered by Claude Perreault and Pierre Thibault’s teams will be tested in humans in 2026.