New discovery could lead to better treatments for cancer and chronic infections

Melbourne scientists hope this world-first discovery will explain why immunotherapy fails in some patients, paving the way for better treatments.

Melbourne scientists have uncovered key cells that are crucial in the fight against cancer and chronic infections, bringing them a step closer to better treatments for both.

Their study, published on Wednesday in Nature, found a specific type of T-cell plays a critical role in maintaining an immune response in mice and could help explain a phenomenon called “immune exhaustion”.

The world-first discovery, from the Doherty Institute in Melbourne and Germany’s Technical University of Munich, could also explain why immunotherapy fails in some patients.

Melbourne University Professor and co-author Axel Kallies said T cells were critical to our immune system, and kill off infected or cancerous cells.

But he said, if a virus persists or a malignant tumour continues to grow, ‘immune exhaustion’ — common in patients with cancer or chronic viral infections — can occur.

It’s hoped the discovery will help develop more targeted, precise treatments and spare patients from having to undergone therapies that would never have worked for them.

“The T-cells will … initially do their best to fight this threat, but they will eventually lose their functionality (against that specific infection or cancer),” he said.

“That then contributes to the escape of these virally infected cells … or the tumour can keep on growing in your body.

“The question in our field has always been, how can we prevent this … how can we prevent the immune system from losing its edge?”

Prof Kallies said they discovered a type of T-cell which act like a stem cell and continually produce “good killer cells”.

“They can essentially self-renew, which means they don’t disappear or exhaust themselves,” he said.

“That is what makes it so exciting, because we can now identify cells that sort of act as a source … for a long-term immune response.”

He said it will take a few years to “really put our finger on” the cells’ human equivalent, but he is excited about the benefits their discovery could lead to.

“I’m actually quite optimistic that this is going to work out in a positive way,” he said.

He said their work may one day help identify which patients will benefit from immunotherapy, and those who should try other treatments instead.

“Our work suggests that these stem-like T cells may be the clue why that is,” he said.

“If a patient for example, lacks the cells or has very few of them, the prediction would be that certain therapies won’t work.”

He said the hope is to develop more targeted, precise treatments and spare patients from having to undergone therapies that would never have worked for them.

“You’re losing time and wasting resources by treating patients with an agent that is not specifically helpful for them.”