The Action Of The Immune System Against Cancer
The immune system is also able to identify and fight its own cellular components. This happens when these are abnormal.
The immune system is a complex defense system whose main function is to protect the body against external agents. For this, it is important to be able to distinguish our own components from foreign bodies.
Moreover, this system is also capable of identifying and combating its own cellular components. This is the case when the latter are abnormal. For example, carcinogenic cells which are different from the normal cell.
It is important to understand that in all types of cancer, the disease process is that certain cells in the body begin to divide without stopping and spread to nearby tissues. Cancer is a dangerous disease and it is essential to have professional help to fight it properly.
Immune system functions
In addition to recognizing and fighting tumor cells, the immune system also has other ways to prevent them from manifesting:
- Protection against viral infections which can lead to the appearance of tumors: this is the case, for example, with the human papillomavirus. In addition, it has great mutagenic potential, so its infection can alter the genetic material of cells.
- Fights by eliminating external pathogens: when there is an infection, the body reacts by developing inflammation around it. However, this inflammation must be resolved effectively because this environment can sometimes generate the appearance of tumors.
- Identification and elimination of carcinogenic cells using specific markers
Surface antigens
But, how does the immune system recognize carcinogenic cells? The answer lies in the surface proteins found in all cells. They are called surface antigens.
The surface antigens of tumor cells are different from those of healthy cells. Thus, cells of the immune system can identify these antigens and detect when they match a mutant cell.
On the other hand, the immune cells capable of accomplishing this recognition task are T lymphocytes. These T lymphocytes have a set of receptors which detect surface antigens.
The action of the immune system against cancer
The reaction of the immune system to cancer begins with the recognition of the mutated cells, thanks to the surface antigens mentioned above. These antigens are examined by the T lymphocytes present in the lymph nodes.
Then the T cells undergo a series of changes and become active. This gives them the ability to move and travel through blood vessels. Thanks to this, the lymphocytes reach the tumor by being directed by gradients in the concentration of certain signaling molecules.
Once they get to the tumor, they infiltrate that area in an attempt to attack it. They then identify the tumor cells which present certain proteins on their surface, and then proceed to their destruction.
However, this is possible by stimulating another set of cells in the immune system. For example, Natural Killer (NK) cells or macrophages.
Leakage mechanisms of tumor cells
The reason cancer develops, despite the action of the immune system, is that some cancer cells have accumulated so many mutations that they have mechanisms to bypass the immune system.
These mechanisms allow tumor cells to hide from the immune system. For example, by obscuring surface antigens that might be recognized.
In these cases, the immune system can defend itself thanks to the Natural Killer cells . These are able to detect when a cell has lost its own surface antigens, recognize it as foreign and eliminate it.
Another mechanism that tumor cells can use to prevent the action of the immune system is to produce chemical messengers which inhibit the immune cells. Thus, they create immunosuppression around the tumor area. This therefore promotes the survival of cancer cells.
For all these reasons, the main goal of immunotherapy is precisely to help the immune system fight off abnormal cells. This can be achieved through adjuvant therapy, which uses antibodies directed against tumor cells in order to promote their elimination.
