Cellular immunotherapy is a method of treating cancer that generally works by triggering the patient’s immune system against tumor cells. It can be accomplished by extracting cells and harvesting a culture to put back in the body. Substances can also be injected to get the process going. The goal is to get the immune system to recognize tumor cells, and overcome the effects of substances called cytokines, which can suppress the immune response to cancer. Various clinical trials have tested different methods of cellular immunotherapy during the first decade of the 21st century.
Methods of cellular immunotherapy include irradiating malignant cells and adding an immune stimulating compound. In another strategy, genes that code for immune responses can be inserted into tumor cells. Cytokines are sometimes used to stimulate the immune system around the affected area; when used locally, side effects are typically avoided. Other type of immunotherapy involves the use of dendritic cells, which typically act as messengers to other types of immune cells. These can be filled with compounds that target cancer cells, and have sometimes been used to create a type of vaccine.
Some cellular immunotherapy treatments make use of immune components called T cells. These treatments often focus on counteracting the ability of many cancers to become unrecognizable to the immune system. Molecules that allow immune cells to target something are often not expressed on a tumor, or there are molecules that kill T cells. Sometimes immune cells from a donor are transplanted to patients with leukemia, and this approach can also be combined with gene therapy.
Genetic engineering can also be used on cells from the patient. Once these are taken from blood sample, molecular receptors can be added and the biological material is grown outside the body. The goal is to re-implant the culture to create a defense against the cancer and eradicate it.
Certain types of cellular immunotherapy have led to autoimmune conditions in people. In treatments that serve as vaccines, some researchers think this response is also possible. Immunotherapies are often used on patients with advanced disease, so the potential of some of them is generally not known. The complexity of cellular therapy often adds to the challenges, and it is typically expensive compared to other treatments. As of 2011, studies using cellular immunotherapy are ongoing, typically focusing on genetic and immune science to help fight cancer, and avoiding the toxic effects of chemotherapy and other treatments.