Immunotherapy is a cancer treatment that strengthens the body’s natural defenses against malignancy (cancer). It employs compounds or cells produced by the body or in a laboratory to increase the ability of the individual’s immune system to detect and eliminate cancer cells.
Immunotherapy works by assisting the immune system in identifying and attacking cancer cells. It may be used alone or in conjunction with other cancer therapies and is rapidly becoming a standard treatment for certain forms of cancer. Immunotherapy comes in a variety of forms: Monoclonal antibodies, checkpoint inhibitors, vaccinations and expansion or production of tumor specific immune cells.
This article will discuss immunotherapy, specifically how the immune system can be optimized to fight cancer.
Immunotherapy and the immune system
Our immune system defends the body against infection, sickness, and disease. It can also help to control the growth and spread of cancer. The lymph glands, spleen, and white blood cells are part of the immune system. Usually, the immune system can detect and kill defective cells in the body, preventing cancer from forming. However, cancer can spread when the immune system fails to recognize cancer cells or fails to effectively kill them.
Cancer cells can also send out signals that prevent the immune system from detecting them allowing cancer cells to hide or evade the immune system.
Immunotherapy aids our immune system in its battle against cancer. Immune-based therapies come in a variety of forms that can operate in many ways to support or enhance our immune response. Some immunotherapies assist the immune system in stopping or slowing cancer cell development. Others aid the immune system in destroying cancer cells or preventing cancer from spreading to other regions of the body. Importantly, immunotherapy approaches can be used independently or in conjunction with other cancer treatments (e.g., radiation and chemotherapy).
Current Immunotherapies comes in a variety of forms:
- Checkpoint inhibitors and monoclonal antibodies to prevent T cell “exhaustion.”
- Oncolytic virus treatment to kill cancer cells
- T-cell immunotherapy to kill cancer cells
T-cell receptor-based cancer therapies
T cells are immune cells that help the body fight illness including cancer. T cell-based cancer therapy involves removing the T cells (called TILs) from biopsy samples of a patient’s cancer, expanding these tumor-reactive T cells and re-injecting them into the patient. In some cases, the protein complex (called the T cell receptor) that recognizes cancer cells is cloned and introduced into patient T cells to make them tumor reactive. Another approach involves introducing synthetic tumor-reactive T cell receptor-like molecules called chimeric antigen receptors (CARs) into patient T cells. Fever, disorientation, low blood pressure, and, in rare cases, seizures are among the side effects of these therapies.
Work of a prominent immunologist
Many prominent immunologists have extensively studied T-cell receptors. Dr. Paul Love, a senior researcher at the National Institutes of Health, has comprehensive research experience in this field. His research focuses primarily on T cell antigen receptor (TCR) signaling, emphasizing the role of immuno-receptor-tyrosine based activation motifs (ITAMs) sequences in subunits of the TCR that are responsible for signal transduction.
Dr. Love developed one of the first gene-targeted models at NIH as a postdoctoral fellow, mice missing expression of the CD3zeta chain of the TCR. His lab has subsequently created mice defective in multiple other TCR subunits. Understanding the function of the TCR’s numerous signal-transducing modules (ITAMs) has been a long-term focus of research in the Love-laboratory. TCRs utilize ITAMs to activate T cells in response to binding foreign proteins (antigens). T cells also identify and eliminate cancer cells and play an essential part in self/non-self-identification. Current research in the Love-laboratory is focused on modifying ITAMs to improve the ability of T cells to kill cancer cells.
Dr. Love’s lab’s research interests are also focussed on mammalian hematopoiesis. The lab has a long history of investigating T cell formation, which begins with migrating multipotent progenitor cells to the thymus from hematopoietic stem cells in the bone marrow. Immature T cells then go through a series of developmental steps in the thymus, including a selection process that promotes the development of functional cells while deleting overtly self-reactive cells, eventually leading to the generation of mature “self-tolerant” T lymphocytes that exit the thymus and populate the peripheral lymphoid organs.
Immunotherapy is a crucial strategy that is currently being used for cancer treatment. The above examples do not include every form of immunotherapy treatment. Scientists are researching many novel approaches that enhance or optimize the body’s immune response to cancer cells. Current research focuses on understanding how TCR signaling influences susceptibility to autoimmune disease and how TCR signaling can be modified to aid tumor immunotherapy.