Using antibodies to boost the immune system’s ability to tackle disease is a relatively new approach that is transforming cancer treatment. Now a new study shows that the shape of an antibody can make a big difference to the effectiveness of so-called cancer immunotherapy.
Researchers from the University of Southampton in the UK found a particular naturally occurring antibody called IgG2 is much more effective at stimulating the immune system to fight cancer than other types of antibody.
They report their findings in the journal Cancer Cell.
Study leader Dr. Ann White, Senior Research Fellow at Southampton, says:
“We know that the immune system provides a natural protection against cancer, which can only grow by finding a way around our defences.”
Antibody treatments are now able to correct this problem for many types of cancer, but we still need them to work better,” she adds.
IgG2 is unique among antibodies because it can work on its own without the help of other immune cells. This makes it more active and effective in all tissue types.
The team found that a version of the antibody – IgG2B – is particularly effective at stimulating antitumor immunity because it has what is known as a “locked B structure.”
The team also found they could engineer antibodies to have this particular shape – thus opening the door to making stronger immune stimulators than previous drugs.
Dr. White notes that while it is early days, a discovery like this could enable doctors to treat cancer more effectively.
“Our next task is to bring these novel IgG2B antibodies into trials for cancer patients and we are engineering ways to make them effective in the clinic,” she adds.
The researchers are now trying to discover why IgG2 works better in a locked B structure.
They have crystallized the molecule and shone X-rays through it to better understand its structure.
To their knowledge, this is the first time anyone has crystallized IgG2.
Professor Nic Jones, chief scientist at Cancer Research UK, the sponsor of the study, comments:
“Energizing the immune cells in our body and getting them to treat cancer cells as a threat gives us a better shot at beating cancer.”
The study is part of growing research in the field of cancer immunotherapy at the University of Southampton.
That study could make a big difference because typically, pancreatic cancer does do not respond to immunotherapy, and fewer than 5% of patients survive 5 years after diagnosis.