Image is from Cancer Research Catalyst – American Association for Cancer Research
Immunotherapy also known as biologic therapy is a type of treatment that induces or enhances the body’s immune system instead of using medicines. This process is usually done to treat cancer by stimulating the immune system to become more active in attacking cancer cells or by sustaining the body with man-made immune system proteins.
How Does the Immune System Work?
The immune system is the sum of all components that work together to maintain the normal functions of body organs. These components include but not limited to white blood cells, nutrients, and organ functions.
When the surface of skin is wounded, white blood cells work to heal the wound by eliminating foreign substances. When the wound is larger, it requires a lot of white blood cells to cover the wounded area. This will result in the appearance of lymph nodes near the area. This is where white blood cells build up.
In the process of eliminating foreign substances such as bacteria, germs, and cancer cells, body nutrients such as vitamin C may work to repair the damaged tissues and collagen.
Meanwhile, body organs work together to prevent disease-causing agents to stay inside the body. Kidney works to filter toxins, which are excreted through the urine. Digestive system separate important substances needed by the body from waste. The heart continues to pump blood to carry white blood cells and red blood cells needed to heal wounds.
These are some examples of how the immune system work. The immune system is not a single substance nor a single organ. It is an integration of several body systems that work together to protect the body from certain diseases.
The Immune System as Treatment for Cancer
There still no single medicine that can cure cancer. So far, an effective way to suppress the spread of cancer cells is through the immune system. The immune system serves as the police inside the body. It detects unwanted substances that may infect any area of the body.
However, cancer cells are not detected by the immune system as they appear to be like normal cells by of sending signals to the PD-1 CTLA-4 receptors. These signals confuse the immune system. This is why even a healthy body with strong immune system cannot prevent cancer.
Nonetheless, there is a way to make cancer cells detected by the immune system. The use of immunotherapy drugs such as inhibitors can disrupt the signals that are sent by cancer cells. This will let the cancer cells exposed to the immune system. Cytokines and cancer vaccines are examples of these inhibitors.
Monoclonal antibodies are man-made immune system proteins. These proteins attach to cancer cells thereby flagging the cancer cells to be recognized by the immune system. On the other hand, monoclonal antibodies work to block the abnormal proteins in cancer cells, so they can also be used to prevent cancer cells from spreading.
These are examples of man-made antibodies:
- Pembrolizumab (Keytruda)
- Nivolumab (Opdivo)
- Ipilimumab (Yervoy)
Non-specific immunotherapies are used to boost the immune system to directly stop and kill cancer cells. Examples of these are interferons and interleukin’s.
The use of the immune system is still the most recommended method in the treatment of cancer. It only needs the help of inhibitors to let it work properly on the target. The problem with the immune system is that it is not intelligent enough to keep cancer cells from being hidden. This is why there is still a need for human intervention with the help of man-made antibodies.