Our body has its style to deal with the invaders and infectious elements using its army of little soldiers called immune cells. Our immune system is remarkable, made of a network of cells, tissues, and organs defending our body from a variety of enemies it may encounter. And yes, cancer is on the list of these enemies.
A bit about the immune system
The immune system is a very powerful biological tool in fighting off pathogens or anything that harms the cells of our body. There are two kinds of immunity, innate and adaptive. The innate immune system acts up against common pathogens and gives a general defense against them. While the adaptive immune system gives a more specific response to a particular kind of pathogen. It learns, adapts, and remembers how to defend and battle against a specific enemy.
Let’s talk about the little soldiers or the immune cells who are the actual players here. Different types of immune cells make up the immune system. B cells are ones that release antibodies targeting a specific pathogen. Each of them can release a specific antibody. These antibodies can attach to a tumor disrupting its functioning and firing an immune response against it.
T cells are of different kinds: helper T cells which signal other immune cells and killer T cells which attack and kill the pathogen or tumor cells. Macrophages engulf and digest any pathogens or cells that pose danger.
If you consider the molecular way of the immune system then you should know about antibodies and cytokines. Antibodies are the protein that binds to the special spots known as antigens on the pathogens invading our body or on cancer cells. So, the antibodies keep a note of these markers or special spots for attacking and destruction by the other immune cells. While cytokines are like messengers which assist the other immune cells to work together and initiate the correct immune response against any pathogens.
How does the immune system respond to cancer?
We have discussed earlier that our immune system can identify and attack cancer cells. It does so by checking the weird antigens which are foreign and not seen in normal cells but are present in the tumor cells. Our immune system goes on attack mode whenever it encounters any foreign particles(as foreign particle means enemy or something harmful). So, it watches and destroys the small tumor cells. This kind of monitoring is immune surveillance.
The immune system stops and keeps a check on the formation of cancerous mass in our body in many ways. One can be by fighting off the pathogen responsible for triggering or causing cancer in your body. An example of this is HPV or human papillomavirus which is responsible for causing cervical cancer in women. You might be aware of this virus. Most of the infections caused by this virus are cleared by your immune system and hence the immune system protects women against this type of cancer.
Immune cells destroy the cells with mutation or abnormalities by recognizing the abnormal antigens on the cells. Another way of its operation is rejection. Let’s try to understand with an example. In the case of nonpolyposis colon cancer mutation, which can be passed through generation, an individual inherits a faulty DNA mismatch system and hence a lot of cells with a mutated protein are produced. Hence, the immune system finds the mutated protein on the surface of the cells, they label them as foreign, and reject them. Tumor cells that are successful in fooling the immune system can only survive.
The immune system does work against the cancer cells and might help to prevent cancer. This is true because the immune deficiency makes you more vulnerable to getting cancer. A weak immunity means that you have an increased risk of getting cancer, especially lymphoma which affects the lymphocytes. Our immune system responds to two kinds of antigens found in tumor cells ie, tumor specific and tumor associated antigens. The tumor-associated antigens are present on both normal as well as tumor cells. While the tumor-specific antigens are only present on tumor cells and are unique to them. These are the kind of antigens that are identified by T cells and bring about an immune response.
Why do we still get cancer?
Even though our immune system seems formidable, it cannot win against cancer. Why the immune system is not so effective against cancer. Before you blame the immune system, you should think in this way. If we didn’t have an immune system then all of us would get cancer which is not the case. Our immune system might be fighting against cancer cells regularly and silently. We might even be aware but the immune cells might likely be helping to keep the cell mutation in check. It only fails when it is overwhelmed by tumours or cancer cells or when tumour cells are able to hide and evade the immune system.
One of the new ways to fight cancer is immunotherapy. It utilises your immune system to fight cancer. It uses antigens as a weapon to target and kill cancer cells. Another way is tumour vaccine, in which T cells are stimulated to find and destroy the cancer cells. This treatment can be combined with other conventional therapies to get the desired result.
Your immune system is amazing and fights the pathogens that are invading your body every second. We don’t stand a chance to win over harmful microbes and foreign particles if we don’t have an immune system. It also promises to find a better way to deal with cancer.