is the " treatment
by inducing, enhancing, or suppressing an immune response". Immunotherapies designed to elicit or amplify an immune response are classified as activation immunotherapies,
while immunotherapies that reduce or suppress are classified as suppression immunotherapies.
In recent years, immunotherapy has become of great interest to researchers, clinicians and pharmaceutical companies
, particularly in its promise to treat various forms of cancer
. Memorial Sloan Kettering Cancer Center|website=www.mskcc.org|language=en|access-date=2017-07-27}}
Immunomodulatory regimens often have fewer side effects than existing drugs, including less potential for creating resistance when treating microbial disease.
Cell-based immunotherapies are effective for some cancers. Immune effector cells such as lymphocyte
s, dendritic cell
s, natural killer cell
s (NK Cell), cytotoxic T lymphocytes
(CTL), etc., work together to defend the body against cancer by targeting abnormal antigens expressed on the surface of tumor cells.
Therapies such as granulocyte colony-stimulating factor
and cellular membrane fractions from bacteria
are licensed for medical use. Others including IL-2
, various chemokine
s, synthetic cytosine phosphate-guanosine (CpG) oligodeoxynucleotides and glucan
s are involved in clinical and preclinical studies.
Immunomodulators are the active agents of immunotherapy. They are a diverse array of recombinant, synthetic, and natural preparations.
Cancer immunotherapy attempts to stimulate the immune system
to destroy tumors. A variety of strategies are in use or are undergoing research and testing. Randomized controlled studies in different cancers resulting in significant increase in survival and disease free period have been reported and its efficacy is enhanced by 20–30% when cell-based immunotherapy is combined with conventional treatment methods.
The extraction of G-CSF lymphocytes
from the blood and expanding in vitro against a tumour antigen before reinjecting the cells with appropriate stimulatory cytokines
. The cells then destroy the tumor cells that express the antigen
immunotherapy for early stage (non-invasive) bladder cancer
instills attenuated live bacteria
into the bladder
and is effective in preventing recurrence in up to two thirds of cases.
Topical immunotherapy utilizes an immune enhancement cream ( imiquimod
) which produces interferon
, causing the recipient's killer T cells
to destroy wart
s, actinic keratoses
, basal cell cancer
, vaginal intraepithelial neoplasia
, squamous cell cancer, cutaneous lymphoma, and superficial malignant melanoma.
Injection immunotherapy ("intralesional" or "intratumoral") uses mumps, candida, the HPV vaccine or trichophytin antigen
injections to treat warts (HPV induced tumors).
Adoptive cell transfer
has been tested on lung
and other cancers.
Dendritic cell-based pump-priming
can be stimulated to activate a cytotoxic
response towards an antigen
. Dendritic cells, a type of antigen presenting cell
, are harvested from the person needing the immunotherapy. These cells are then either pulsed with an antigen or tumor lysate or transfected
with a viral vector
, causing them to display the antigen. Upon transfusion into the person, these activated cells present the antigen to the effector lymphocytes ( CD4+ helper T cells
, cytotoxic CD8+ T cells
and B cell
s). This initiates a cytotoxic response against tumor cells expressing the antigen (against which the adaptive response has now been primed). The cancer vaccine Sipuleucel-T
is one example of this approach.
T-cell adoptive transfer
Adoptive cell transfer in vitro
cultivates autologous, extracted T cells for later transfusion. The T cells may already target tumor cells. Alternatively, they may be genetically engineered to do so. These T cells, referred to as tumor-infiltrating lymphocyte
s (TIL), are multiplied using high concentrations of Interleukin-2
, anti-CD3 and allo-reactive feeder cells. These T cells are then transferred back into the person along with administration of IL-2 to further boost their anti-cancer activity.
Before reinfusion, lymphodepletion of the recipient is required to eliminate regulatory T cells as well as unmodified, endogenous lymphocytes that compete with the transferred cells for homeostatic cytokines. Lymphodepletion can be achieved by total body irradiation. Transferred cells multiplied in vivo
and persisted in peripheral blood in many people, sometimes representing levels of 75% of all CD8+ T cells at 6–12 months after infusion. As of 2012, clinical trials for metastatic melanoma were ongoing at multiple sites.
=Immune enhancement therapy
Autologous immune enhancement therapy
use a person's own peripheral blood-derived natural killer cell
s, cytotoxic T lymphocytes and other relevant immune cells are expanded in vitro
and then reinfused. The therapy has been tested against Hepatitis C
, Chronic fatigue syndrome
=Genetically engineered T cells
Genetically engineered T cell
s are created by harvesting T cells and then infecting the T cells with a retrovirus
that contains a copy of a T cell receptor
(TCR) gene that is specialised to recognise tumour antigens. The virus integrates the receptor into the T cells' genome
. The cells are expanded non-specifically and/or stimulated. The cells are then reinfused and produce an immune response against the tumour cells. The technique has been tested on refractory stage IV metastatic melanomas and advanced skin cancer
Another potential use of immunotherapy is to restore the immune system of people with immune deficiencies. Cytokines
have been tested in clinical trials.
immunotherapy, which includes vaccination
, involves activating the immune system
to respond to an infectious agent.
dampens an abnormal immune response
in autoimmune diseases
or reduces a normal immune response
to prevent rejection
organs or cells.
s help manage organ transplantation and autoimmune disease. Immune responses depend on lymphocyte proliferation. Cytostatic drugs
are immunosuppressive. Glucocorticoids
are somewhat more specific inhibitors of lymphocyte activation, whereas inhibitors of immunophilins
more specifically target T lymphocyte activation. Immunosuppressive antibodies
target steps in the immune response. Other drugs
modulate immune responses.
The body naturally does not launch an immune system attack on its own tissues. Immune tolerance therapies seek to reset the immune system so that the body stops mistakenly attacking its own organs or cells in autoimmune disease
or accepts foreign tissue in organ transplant
ation. Creating immunity reduces or eliminates the need for lifelong immunosuppression and attendant side effects. It has been tested on transplantations, and type 1 diabetes
or other autoimmune disorders.
Immunotherapy is used to treat allergies
. While allergy treatments (such as antihistamine
s or corticosteroids
) treat allergic symptoms, immunotherapy can reduce sensitivity to allergen
s, lessening its severity.
Immunotherapy may produce long-term benefits. Immunotherapy is partly effective in some people and ineffective in others, but it offers allergy sufferers a chance to reduce or stop their symptoms.
The therapy is indicated for people who are extremely allergic or who cannot avoid specific allergen
s. Immunotherapy is generally not indicated for food or medicinal allergies. This therapy is particularly useful for people with allergic rhinitis
The first dose contain tiny amounts of the allergen or antigen. Dosages increase over time, as the person becomes desensitized. This technique has been tested on infants to prevent peanut allergies.
) and Hookworm
) have been tested for immunological diseases and allergies. Helminthic therapy
has been investigated as a treatment for relapsing remitting multiple sclerosis Crohn’s
, allergies and asthma. The mechanism of how the helminths modulate the immune response, is unknown. Hypothesized mechanisms include re-polarisation of the Th1 / Th2 response and modulation of dendritic cell function. The helminths down regulate the pro-inflammatory Th1 cytokines, Interleukin-12
(IL-12), Interferon-Gamma (IFN-γ) and Tumour Necrosis Factor-Alpha
(TNF-ά), while promoting the production of regulatory Th2 cytokines such as IL-10
Co-evolution with helminths has shaped some of the genes associated with Interleukin
expression and immunological disorders, such Crohn's
, ulcerative colitis
and celiac disease
. Helminth's relationship to humans as hosts should be classified as mutualistic or symbiotic