Conventional cancer treatments, such as chemotherapy and radiation therapy, come with the drawback where they might also suppress or weaken our immune system by lowering the number of white blood cells and other immune system cells.
Immunotherapy is a relatively new type of cancer treatment that seeks to strengthen our immune system to fight cancer. But it is only effective in treating certain types of cancer.
Over two years ago, researchers in the UK accidentally discovered a type of immune cell that appears to have the power to detect and kill many kinds of cancer cells—at least all the cancers the team had tested. This discovery makes the outlook of finding a universal treatment for cancer ever more promising.
T Cells: The ‘Trained Assassins’ in Our Immune System
Before going into the discovery, we should first introduce an important immune cell.
As an important part of the immune system, T-cells are a type of white blood cell that originate in the bone marrow and mature in the thymus. They travel to different parts of the body to hunt down foreign substances deemed harmful to the body.
Professor Gillian Griffiths from the Cambridge Institute for Medical Research describes T cells as “trained assassins that are sent on their deadly missions by the immune system. There are billions of them in our blood, each engaged in a ferocious and unrelenting battle to keep us healthy. Once a T cell has found its target, it binds to it and releases its toxic cargo.”
How do T cells find their targets?
On the surface of a T cell is a type of protein called a receptor. When the T cells travel around in the body, the receptors sniff the surface of other cells looking for clues that might signal an abnormality or a foreign invasion. There are many different types of T cell receptors, each has a specific target. Take the cancer-targeting receptors, for example: they can sniff out proteins or other molecules (antigens) that are found only on cancer cells.
Following this method, the scientists have found ways to produce specific receptors that target different kinds of cancer. The “CAR T cell therapy” is the latest cutting-edge cancer treatment using this method, which we will go into detail about.
This is what we currently know about T cells, but there seems to be more to the T cell that we have yet to understand.
The Discovery of a Ubiquitous T-cell
Researchers at Cardiff University in the UK have discovered a special type of T cell that can kill many different types of cancer cells. Their paper was published in Natural Immunology in January 2020.
The Cardiff researchers were originally looking for a kind of T cell that can kill a bunch of bacteria. They happened to use cancer cells as the hosts of the bacteria, since cancer cells can be easily infected with different bacteria.
To their astonishment, they discovered a special type of T cell that not only killed the bacteria (as expected), but also killed ALL the cancer cells–with or without bacteria inside them–used in the experiment.
This discovery sparked their curiosity–is this new hope for universal cure for cancer?
Then they tested other types of cancer in mice who were given human cancers. Lung cancer, colon cancer, bone cancer, breast cancer, blood cancer, skin cancer–all cancer cells used by the researchers were killed by this one type of T cell. What was even more surprising is that this T-cell left the normal cells untouched.
Take melanoma as an example:
The ‘Smoking Gun’ Protein–MR1
Established research tells us that T cells are highly specialized in detecting a certain type of protein on the surface of a cell.
How can this new T cell detect so many different types of cancer cells? Perhaps there is one “smoking gun” antigen that is common among many different cancer cells?
To test this hypothesis, the Cardiff researchers deleted the proteins from the surface of cancer cells one at a time (using CRISPR-Cas 9 gene editing). If the T cell stops working after a protein is deleted, then that protein is the smoking gun.
They did find a protein called MR1. However, MR1 is found on all cells, not just cancerous cells. So, the scientists do not know exactly what information inside MR1 that enables the new T cell to differentiate cancer cells from normal cells.
In their own words, the Cardiff researchers wrote, the receptor “does not recognize MR1 by known mechanisms.”
More research is underway to determine the communication mechanism between MR1 protein and the receptor on the new T cell.
Engineering T Cells to Treat Cancer: CAR T Cell Therapy
The CAR T-cell therapy strengthens a cancer patient’s immune system by adding a lab-produced receptor to the patient’s T cells. This lab-made receptor, called Chimeric Antigen Receptor (CAR), can sniff out the specific type of cancer cells in the patient. In other words, the CARs can recognize and bind to the specific antigens on the surface of cancer cells.
CARs don’t exist naturally, but once they are infused back into the patient’s body, they can continue to multiply in the patient’s blood.
Since 2017, six CAR T-cell therapies have been approved for the treatment of certain blood cancers by the Food and Drug Administration.
Because the CARs must be produced in the lab tailored to each patient, cost is a huge factor. The recently approved CAR T-cell therapy is more than $450,000.
Professor Awen Gallimore, Co-Director of Systems Immunity Research Institute at Cardiff University, told EurekAlert.org in January 2020, “If this transformative new finding holds up, it will lay the foundation for a ‘universal’ T-cell medicine, mitigating against the tremendous costs associated with the identification, generation and manufacture of personalized T-cells.”
The Epoch Times reached out to researchers at Cardiff University.
