Immunotherapy
A GOOD LIFESTYLE can help us to feel better and live longer. Our lifestyle can affect not only how long we live, but also how healthy we feel now. We are continually exposed to various foreign particles, including infectious agents such as bacteria, virus and other parasites.
People, who are survivors of certain diseases caused by these, are not attacked by the same diseases again because their bodies would have become immune to those diseases.
The word “immunity” is derived from a Latin term IMMUNIS, which means “exempt” or “freedom”.
Immunity refers to all types of mechanisms used by the body for protection from agents that are foreign to the body. The agents may be microorganisms or their products, chemicals, drugs, certain food items, pollen etc.
All types of defence elements with which an individual is born to protect a living body is referred to as innate immunity. It consists of various types of barriers such as skin, mucous membrane, body temperature, pH, various body secretions, white blood cells etc.
Acquired immunity is the adaptive or specific immunity which has the capacity to recognize and selectively eliminate specific foreign agents. It involves two major groups of cells, lymphocytes (T and B) and antigen presenting cells.
Immune system plays an important role in preventing cancer. White blood cells, or leukocytes, play the main role in immune response.
A special type of white blood cells called “KILLER” cells, which are part of the immune system, identify cancer cells by the changes in their surface membrane. Other cells called” HELPER” cells assist the “KILLER” cells to destroy cancer cells. It includes a group of organs, special cells, and substances that help protect the body from infections and some other diseases.
They travel through the body to protect it from germs that cause infections. The immune system recognises the substances that are not normally found in the human body and treats them as “foreign” and attacks them.
An improper function of the immune system can cause discomfort, disease or even death. It may cause hypersensitivity or allergy, auto-immune diseases like insulin – dependent diabetes, multiple sclerosis, rheumatoid arthritis, and immunodeficiency diseases like AIDS, SCID (Severe Combined Immunodeficiency), malnutrition or accidents.
Manipulation of the immune response can be carried out by modulating various components involved in it. It is brought about by the active agents of immunotherapy known as Immunomodulators.
Natural Immunomodulators like cytokines are secreted by one type of immune cell and they bring about response in another type of immune cell.
Immunomodulators modulate the activity of a patient’s immune response, either up or down, until a desired level of therapeutic effect is reached. Such a treatment procedure that involves suppression or augmentation of immune responses, to achieve therapeutic effects is referred to as IMMUNOTHERAPY. It is one of the recent approaches of cancer treatment developed in the 1970s.
Immunotherapy is a biologic therapy used to treat all cancers and it increases the capacity of body's natural defence system to fight the cancer.
Immunotherapy is an effective treatment for patients with certain types of cancer like melanoma, which are resistant to chemotherapy and radiation treatment.
In cancer immunotherapy, the immune system is stimulated to destroy tumours. Immunotherapy stops or slows the growth of cancer cells. It stops the cancer from spreading to other parts of the body. It also helps the immune system in destroying cancer cells.
There are two types of IMMUNOTHERAPIES,
Immunopotentiation therapy that includes administration of Immunopotentiation agents like preformed antibodies, or drugs. They increase the immune response.
Immunosuppressive therapy includes inhibitors of cell division. When patient’s immune system becomes activated against his or her own body, like autoimmune diseases, the response is suppressed by using specific therapies.
The main types of cancer immunotherapy now being used to treat cancer are
Monoclonal antibodies, Immune checkpoint inhibitors, Non-specific immunotherapies, Cancer vaccines, Oncolytic virus therapy and T-cell therapy.
Monoclonal antibodies (mAb or moAb) are antibodies that are clones of a unique parent cell and all are made by identical immune cells. They are made by cell culture and are used as a targeted therapy. Monoclonal antibodies attach to specific abnormal proteins on cancer cells so that the immune system can identify and destroy those cells.
The immune system has certain pathways called Immune checkpoints which are critical to it to control cancer growth. With the help of specific antibodies called Immune checkpoint inhibitors, the immune system blocks these pathways.
Non-specific immunotherapies also destroy cancer cells and they include Interferons and Interleukins.
Genetically modified viruses are used to kill cancer cells in Oncolytic virus therapy. They do not enter healthy cells.
T- Cell therapy
T- Cells are immune cells involved in immunity. Some of these cells are isolated from patient’s body and are changed in the laboratory, so that they contain specific proteins called receptors. They help the T- cells to recognise the cancer cells. This type of therapy is called chimeric antigen receptor (CAR) T-cell therapy.
Cancer vaccines make the antigen to expose. Then the immune system recognises and destroys that antigen.
Both chemotherapy and radiation damage healthy cells, leading to hair loss and nausea/vomiting. Immunotherapy may not cause the same side effects as chemotherapy and radiation. The side effects may be flu-like symptoms, Fever, Chills, Weakness, Dizziness, Nausea or vomiting, Muscle or joint aches, Fatigue and Headache.
Research is still going on to find out new methods of immunotherapy to treat cancer in the future.
