Welcome back, Steminists! We hope you are having a restful time remote learning and working and are excited for the loosening of lockdown which will commence soon in the UK. Today, we have a fascinating and very topical blog post from one of our new monthly writers, the talented Aleksandra. Applications are still open to join our team of monthly writers so make sure to complete the contact form on this website if you are interested and tell us what you would bring to the team. We also accept one off submissions and would love to read your STEM articles!
Have you ever thought about a huge, powerful army that protects you every day? This army is called the immune system and consists of a large number of different compounds. There are a lot of soldiers that protect us from pathogens and other microorganisms that could be dangerous and cause illnesses. Some of them are called B-lymphocytes and T-lymphocytes and they have properties that make them one of the most amazing things ever- they can remember antigens they have encountered before.
This army can be used in an innovative cancer treatment called immunotherapy that uses our own immune system to fight tumors. Isn’t it an amazing idea? It is so much different from cancer treatments we know. In the past, we generally had only three options to fight with cancer: chemotherapy, radiotherapy and surgery. But now we have a new player, immunotherapy, that is constantly getting into power.
Have you ever thought about why our immune system, so precise and genius, can’t see cancer? Sometimes the person notices a tumor before their immune system does. Earlier scientists thought that’s because cancer cells are too similar to our own healthy cells.By the way, it’s worth to know that tumor cells are actually our own cells that due to some factors mutated and don’t work properly. However, it turned out that there’s another reason why cancer is so often invisible for our immune system that makes it probably the best player in hide and seek play ever.
Apparently, cancer learnt how to express structures that are usually found on our healthy cells: these structures are called checkpoints. If our immune system finds a checkpoint on a surface of the cell it thinks that the cell works properly and that everything is okay. Therefore, if a checkpoint is found on the surface of a cancer cell, it gives a false signal that the cell is healthy and that is not a risk for the organism.
One type of immunotherapy tries to block checkpoints found on tumor cells- so they can’t bind to the T-cells. Therefore off-signal is not sent and the immune response can work properly and consequently, dangerous cancer cells are killed. We know only several types of different checkpoints but scientists think that there might be a lot more of them- it gives a chance of improving checkpoint inhibitors immunotherapy in the future, so it can make the outlook better for more cancer patients.
Another type of immunotherapy uses patient’s own T-cells that are changed in the lab so they can fight tumor cells better. This therapy is called CAR T-cell therapy, it's now used for a lot different types of cancer and it’s proven to give a better outlook for a large number of patients. In 2017 Food and Drug Administration (FDA) approved two CAR-T cell therapies- one of them for children with acute lymphoblastic leukemia and the other one for adults with lymphomas in late stages.
This sounds pretty cool, but generally, how does it work? So, the T-cells are manufactured in a lab to produce a special type of a receptor found on their surface - called chimeric antigen receptors. The procedure is quite simple, the blood is taken from the patient and T-cells are separated. Then the disarmed virus is inserted into T-cells and changes their DNA information so they are able to express gene coding for CAR. Later T-cells are grown into millions of copies (our huge army) and inserted again into the patient's bloodstream.
Receptors manufactured in the lab are essential- they enable T-cells to attach to specific antigens found on a surface of cancer cells and start an immune response, so cancer is no longer invisible.
Immunotherapy is a big hope for thousands of scientists, physicians and patients that gives the prospect for improving the whole field of cancer treatments. Hundreds of studies are held right now to continuously broaden our knowledge how our immune system works and how it can be useful in fighting cancer.
Bibliography:
Charles Chraeber 'The Breakthrough'
Cancer.gov
Biospace.com
'Lung Cancer' Gresham College, Prof. Chris Whitty (2019)
Sciencedirect.com
Britannica.com