Active immunotherapy

Active immunotherapy is a type of immunotherapy that aims to stimulate the host's immune system or a specific immune response to a disease or pathogen and is most commonly used in cancer treatments.^[1][2] Active immunotherapy is also used for treatment of neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, prion disease, and multiple sclerosis.^[3] Active immunotherapies induce an immune response through direct immune system stimulation, while immunotherapies that administer antibodies directly to the system are classified as passive immunotherapies.^[4] Active immunotherapies can elicit generic and specific immune responses depending on the goal of the treatment.^[5] The categories of active immunotherapy divide into:

• Non-specific active immunotherapy: generating a general immune system response using cytokines and other cell signaling molecules.^[6]
• Specific active immunotherapy: the generation of cell-mediated and antibody immune responses focused on specific antigens expressed by the cancer cells, typically using a vaccine platform.^[5]

Active immunotherapies fall under the category of activation immunotherapies, which is a subset of immunotherapies that activate the immune system as opposed immunotherapies that suppress the immune system.

Non-specific active immunotherapy is administered with the overall goal of generally eliminating malignant pathogens or cells from the host system.^[5] This treatment stimulates the immune system in a general sense, rather than specifically targeting a cell type e.g. cancer cells. Non-specific approaches aim to create a robust immune response that would lead to the eventual killing of malignant cells through immunomodulators such as cytokines.^[6]

Immunomodulating agents regulate the immune system's response and are produced by various immune cells. These agents include the following agents and markers:

The BCG vaccine has been used against tuberculosis, mycobacteria, and various cancers in the form of vaccination as an initial immune system stimulant.^[7] In cancer, the anti-tumor immunological effects are elicited by the host's immune response and the BCG infection against the tumor cells, most commonly in bladder cancer.^[7] The immune activation allows for further recognition and elimination of malignant tumor cells.^[7]

Specific active immunotherapy administers a specific antigen as the therapy. The therapy allows the host to create an antigen-specific response with the development of antibodies, proliferation of cytotoxic T lymphocyte responses, or both, directed at the desired pathogen or malignant tumor cell in the case of cancer therapy.^[5]

Vaccine therapies are a type of specific active immunotherapy. Vaccine therapies deliver various agents that will lead to a specific immune response e.g. antibody development or CTL response.^[5] Tumor antigens have been a main target in specific active immunotherapy by way of vaccination. Tumor antigens are antigens produced by tumor cells and can be common among patients with the same cancer-type, or unique to a particular patient. Their specificity to malignant tumor cells makes tumor antigens ideal candidates for vaccination.^[2]

• Cancer vaccine
• C-Met#Active immunotherapy,
• Alzheimer's disease clinical research#Active immunotherapy,
• Mantle cell lymphoma § Immunotherapy,