Harnessing the immune system to fight cancer
If Dr Claude Perreault has his way, a simple injection may one day become the cure for many cancers.
Dr Perreault is looking for ways to use the body’s infection-fighting T cells to attack cancer just as they attack viruses like the flu.
“Our thinking is that we should treat cancer cells like infected cells,” says Dr Perreault, a researcher at the Institute for Research in Immunology and Cancer and professor of medicine at the Université de Montréal.
It’s been well established that T cells taken from a healthy donor and injected into leukemia patients can destroy cancer cells. In fact, these injections are more potent cancer-fighting agents than chemotherapy or radiation.
The big problem is that the donor’s T cells also attack healthy cells, and the health effects are often fatal.
With funding from the Canadian Cancer Society, Dr Perreault was the first to find a way around the problem and prove that T-cell injections could destroy leukemia cells while sparing normal cells in mice.
His finding attracted international attention. Since then, he’s shown that his technique also works on solid tumours of the skin and colon.
“The key to success was to inject T cells that see cancer cells as “non-self” and therefore reject them. Indeed, cancer is caused by genetic mutations and the survival of cancer cells depends on these mutations. But fortunately, there is a price to pay: mutations produce non-self molecules that can be sensed by the T cells.”
Society funding has allowed Dr Perreault’s team to develop a novel method for discovering mutation-induced non-self molecules on cancer cells. Using this method, they have recently discovered a whole universe of cancer molecules that can be detected by T cells in mice. Dr Perreault believes that these molecules are the “Achilles heel” of cancer cells – not just in mice but also in people. “The immune systems of a mouse and a human are almost identical, so I am very optimistic.”
Dr Perreault is now using a new approach to identify molecules that attract the T cells’ cancer-fighting abilities. These findings could help increase the number of people with cancer who could benefit from immunotherapies, especially those who are resistant to more conventional treatments like chemotherapy. This work was highlighted as one of the Top 10 Society-funded research stories of 2014.
“Over the years, the Canadian Cancer Society has been pivotal in supporting cancer research in my group,” says Dr Perreault. “Moreover, frequent interactions with Society staff, volunteers and scientists have been an enduring source of motivation and inspiration.”