We could be one step closer to personalized cancer vaccines; in what has been hailed a “groundbreaking” discovery, researchers suggest it could be possible to encourage the immune system to target and destroy cancer cells by identifying specific antigens on their surface.
In the journal Science, an international research team reveals how T cells - white blood cells that help the body fight infection - can recognize antigens that represent genetic faults, or mutations, in cancer cells.
Study coauthor Prof. Charles Swanton, of the University College London (UCL) Cancer Institute in the UK, and colleagues say the findings open the door to immunotherapies that could prime these T cells to identify the unique mutations and kill cancer cells.
Immunotherapy for the treatment of cancer - using a patient’s own immune cells to fight the disease - has been increasingly investigated in recent years, medicalnewstoday.com reported.
But there is one major barrier preventing the treatment from moving forward: the inability to guide immune cells toward the exact cancer cells they need to kill, while avoiding the destruction of healthy cells.
This latest study may have uncovered much-needed targets on cancer cells, bringing researchers closer to a more precise, effective form of immunotherapy.
“For many years we have studied how the immune response to cancer is regulated without a clear understanding of what it is that immune cells recognize on cancerous cells,” says study coauthor Dr. Sergio Quezada, head of the Immune Regulation and Cancer Immunotherapy Laboratory at the UCL Cancer Institute.
“Based on these new findings, we will be able to tell the immune system how to specifically recognize and attack tumors.”
Researchers explain that as a tumor grows, a number of unique mutations arise in its various parts. These mutations produce antigens on the surface of cancer cells within a tumor, which act as “flags” for T cells, prompting them to launch an attack.
“Like Hoodlums”
While the T cells have the ability to eradicate all cancer cells within a tumor, they are not always able to reach their goal. The tumor can either launch a defense mechanism that deactivates the immune cells, or there are often simply too many mutations for the T cells to recognize and attack.
“Genetically diverse tumors are like a gang of hoodlums involved in different crimes - from robbery to smuggling. And the immune system struggles to keep on top of the cancer - just as it’s difficult for police when there’s so much going on,” explains Dr. Quezada.
For their study, researchers used The Cancer Genome Atlas (TCGA) to analyze the genetic data of more than 200 patients with one of two different forms of lung cancer - adenocarcinoma and squamous cell carcinoma.
Moving to the lab, the team isolated T cells from the tumors of two lung cancer patients. They found that their T cells were able to recognize these common antigens, suggesting that tumors contain immune cells that have the ability to identify cancer cells as harmful.
A vaccine could be developed that switches on these T cells in a cancer patient, or it may be possible to harvest, grow or administer T cells back into a patient that can identify the common antigens present in each cancer cell.
