This section assumes knowledge from the sections: Immune system, Cancer, Protein synthesis, Human cells, Basic biology.
The following section is on a treatment of cancer, it is not a guide on how to perform it, nor is it a guide as to the side effects or how to prepare for treatment. The following section is designed to give readers an in-depth understanding of the treatment, how it functions, and why it functions. Please note that researchers are constantly working to find new treatments or improve current ones, this means the subject(s) discussed below are likely to change as medicine improves.
The basic principle of immune therapy or immunotherapy is to use the body’s natural immune system to fight cancer. As covered in the immune system section, the body fights foreign pathogens by identifying antigens. Cancer cells usually evade the immune system either because they have not mutated to produce new/abnormal proteins, or by having surface proteins that deactivate the immune system. Immune therapy only works if the cancer cells have mutated in a way that they produce something that is not normally inside that organism.
There are a few different types of immune therapy such as monoclonal antibodies, T-cell transfer therapy, immune checkpoint inhibitors, and treatment vaccines.
Monoclonal antibodies: antibodies that are made outside of the body, usually synthetically, although some older techniques used other animals to produce antibodies. These antibodies are specifically made to bind to a target protein that has been identified in the cancerous cells. Antibodies that bind to these proteins, and in turn the cancerous cells, can inhibit cellular function and/or mark the cell for destruction by the body’s natural immune system.
T-cell transfer therapy: the patient’s T cells are removed and taken to a lab where they can be enhanced to attack tumours more effectively. This can be done through 2 ways; the first is TIL therapy (tumour infiltrating lymphocytes) where they are tested to see which of the T cells are best at identifying the cancerous cells. The best performing cells can then be selected and replicated, the new specialised T cells can then be reintroduced to the patient.
Note: TIL therapy is very similar to the modern day practice of selective breeding. Only the best of each generation is allowed to breed, over time the population trends towards the traits we determine to be positive, some traits could include: cuteness, milk production, muscle mass, and crop yield.
The second involves genetic editing, where the patients T cells are introduced to the CAR gene (chimeric antigen receptor), this gene causes the T-cells to create specific proteins that will bind to the tumour. The CAR gene is not a universal sequence, it is edited to match a variety of common antigens that could be produced by cancers. This is known as CAR-T therapy. (1)
Immune checkpoint inhibitors: There are a large variety of receptors found on most healthy cells in the body that signal to the immune system that they are healthy and should not be destroyed. This is to prevent autoimmune diseases. By introducing drugs that block those receptors (usually by binding to them), it can make the immune system far more aggressive. This usually leads to an increase of cancer recognition from the immune system. Although by disabling the immune checkpoints there is a higher chance for autoimmune disease.
Treatment vaccines: If the immune system is recognising the cancer cells but slowly or inefficiently, patients can receive treatment vaccines. This is where larger amounts of the antigen that the immune cells are reacting to is released into the body. This causes cells that do react to the antigen to replicate more, leading to a bigger immune response. (2)
Immune system modulators: this is where the natural cytokines that regulate the immune system are artificially introduced in order to activate the immune system and cause a larger response. (3)
| 1. | National Cancer Institute. T-Cell Transfer Therapy – Immunotherapy. Cancer.gov; 2022. Accessed July 20, 2026. https://www.cancer.gov/about-cancer/treatment/types/immunotherapy/t-cell-transfer-therapy |
| 2. | National Cancer Institute. Cancer Treatment Vaccines – Immunotherapy. Cancer.gov; 2019. Accessed July 20, 2026. https://www.cancer.gov/about-cancer/treatment/types/immunotherapy/cancer-treatment-vaccines |
| 3. | National Cancer Institute. Immune System Modulators for Cancer Therapy – National Cancer Institute. National Cancer Institute; 2019. Accessed July 20, 2026. https://www.cancer.gov/about-cancer/treatment/types/immunotherapy/immune-system-modulators |
| 4. | National Cancer Institute. Immunotherapy to Treat Cancer. Cancer.gov; 2019. Accessed July 20, 2026. https://www.cancer.gov/about-cancer/treatment/types/immunotherapy |