Our bodies are equipped with impressive natural defences when fighting cancer. One of the unsung heroes in this battle is a type of immune cell called the Natural Killer (NK).
As the name suggests, these cells are our body’s frontline soldiers, always looking for rogue cells that could turn into cancer. But, as many of us know all too well, cancer is a cunning enemy, constantly evolving new tricks to evade our immune system’s best efforts.
Now, thanks to a groundbreaking discovery from researchers at Monash University and Melbourne-based biotech company oNKo-Innate, there’s fresh hope that we might soon be able to give our immune system the upper hand in this ongoing fight.
Our bodies naturally produce a growth factor called IL-15. Think of it as a kind of ‘fuel’ for our immune system, especially for those all-important NK cells.
IL-15 helps these cells multiply and become more effective at spotting and destroying cancer cells before they can take hold.
Unfortunately, cancer cells are notorious for finding ways to suppress our immune response, even when IL-15 is present.
They can essentially ‘hide’ from NK cells or dampen their activity, allowing tumours to grow unchecked.
Scientists have tried to overcome this by giving patients drugs that activate the IL-15 receptor, but this approach has often backfired.
It supercharges immune cells throughout the entire body, not just at the tumour site, leading to severe side effects.
A more innovative, safer approach
Here’s where the new research comes in. The Monash and oNKo-Innate team, led by Professor Nick Huntington, discovered a gene in NK cells that acts like a ‘brake’ on their sensitivity to IL-15.
By switching off this gene, NK cells became much more responsive to even tiny amounts of IL-15 without needing high, potentially toxic drug doses.
In preclinical models of colorectal cancer, these ‘supercharged’ NK cells were able to slow tumour growth significantly.
Even more exciting, the gene encodes an enzyme, which could be targeted with a pill or injection, making this a practical treatment option.
Colorectal cancer cells, in particular, tend to produce more IL-15 than healthy tissues. However, they can also mutate the IL-15 gene to weaken the immune response, which is linked to cancer coming back and poorer outcomes.
By making NK cells ultra-sensitive to the body’s own IL-15, this new approach could help focus the immune attack right where it’s needed—at the tumour—while sparing healthy tissues and reducing side effects.
The researchers used a cutting-edge technique called CRISPR screening to identify not just one, but two genes that could be targeted to boost NK cell activity.
These genes could be deleted in cell therapies or blocked with small-molecule drugs, opening up a range of new treatment possibilities.
A new era in immunotherapy
This discovery could be a game-changer, especially when combined with existing cancer treatments like immune checkpoint inhibitors (which many of you may have heard about in the news).
According to Jai Rautela, chief executive officer of oNKo-Innate, drugs that enhance IL-15 signalling could provide an extra layer of support for the immune system, particularly in advanced cancers where current treatments sometimes fall short.
As Professor Huntington puts it, this is a prime example of how ‘deep immunology’—understanding the nuts and bolts of our immune system—can lead to new solutions for some of the toughest challenges in cancer treatment.
While this research is still in its early stages, it’s a promising step forward. The fact that similar drugs have already been tested in other blood cancers gives hope that safer, more targeted treatments could be on the horizon for a range of cancers.
Have you or someone you know been affected by cancer? What are your thoughts on these new developments in immunotherapy? We’d love to hear your stories, questions, and opinions in the comments below.
Also read: Australian scientists unveil blood test to spot ovarian cancer early
