| 单词 | immunotherapy | |||
| 释义 | immunotherapyim·mu·no·ther·a·pyI0052000 (ĭm′yə-nō-thĕr′ə-pē, ĭ-myo͞o′-)immunotherapy(ˌɪmjʊnəʊˈθɛrəpɪ)im•mu•no•ther•a•py(ˌɪm yə noʊˈθɛr ə pi, ɪˌmyu-)n., pl. -pies.
ImmunotherapyImmunotherapyThe treatment of cancer by improving the ability of a tumor-bearing individual (the host) to reject the tumor immunologically. There are molecules on the surface of tumor cells, and perhaps in their interior, that are recognized as different from normal structures by the immune system and thus generate an immune response. The two components of the immune response are cell-mediated and antibody-mediated immunity, which must work in concert to overcome tumor cells. One type of thymus-derived lymphocyte (also called a cytotoxic T cell) can destroy tumor cells directly, while another recruits other white blood cells, the macrophages, that do the killing. Natural killer cells and perhaps other white blood cells may also participate. However, elements that normally regulate immunity, such as suppressor T cells, are stimulated excessively by the tumor, which leads to an immune response that is deficient and unable to reject the growing tumor. Thus the strategy of immunotherapy is to stimulate within or transfer to the tumor-bearing individual the appropriate antitumor elements while avoiding further stimulation of suppressor elements. See Cellular immunology, Immunologic cytotoxicity, Immunosuppression There are four broad categories of immunotherapy: active, adoptive, restorative, and passive. Active immunotherapy attempts to stimulate the host's intrinsic immune response to the tumor, either nonspecifically or specifically. Nonspecific active immunotherapy utilizes materials that have no apparent antigenic relationship to the tumor, but have modulatory effects on the immune system, stimulating macrophages, lymphocytes, and natural killer cells. Specific active immunotherapy attempts to stimulate specific antitumor responses with tumor-associated antigens as the immunizing materials. Adoptive immunotherapy involves the transfer of immunologically competent white blood cells or their precursors into the host. Bone marrow transplantation, while performed principally for the replacement of hematopoietic stem cells, can also be viewed as adoptive immunotherapy. Restorative immunotherapy comprises the direct and indirect restoration of deficient immunological function through any means other than the direct transfer of cells. Passive immunotherapy means the transfer of antibodies to tumor-bearing recipients. This approach has been made feasible by the development of hybridoma technology, which now permits the production of large quantities of monoclonal antibodies specific for an antigenic determinant on tumor cells. See Genetic engineering, Immunology, Monoclonal antibodies Immunotherapya branch of practical immunology concerned with the treatment of infectious diseases through the use of immunological preparations, such as vaccines, immune sera, and gamma globulins. Sera and gamma globulins are used for acute types of disease, such as diphtheria, tetanus, botulism, and cerebrospinal meningitis. Vaccines are injected for protracted, sluggish, and chronic forms of infection, such as dysentery, brucellosis, and tularemia. Immunotherapy is combined with antibiotics and chemotherapy. In veterinary medicine, infectious diseases are treated by injecting affected animals with therapeutic sera and bacteriophages. When injected with therapeutic serum or the gamma globulin obtained from it the animal receives, in ready form, protective substances (antibodies) against the causative agent of the disease or its toxin. immunotherapy[¦im·yə·nō′ther·ə·pē]See Immunotherapy immunotherapyimmunotherapy[im″u-no-ther´ah-pe]Nonspecific immunotherapy relies on general immune stimulants to activate the whole immune system. In the past decade, immunotherapy against cancer has involved the use of the bacille Calmette-Guérin vaccine (bcg vaccine), which is evolved from strains of Mycobacterium tuberculosis, and is used to provide some immunity to tuberculosis. A growing body of knowledge allows scientists to devise mechanisms to utilize an individual's own defenses to attack foreign cells, such as cancer cells. One drawback to the use of general immune stimulants is that there is a limit to how much the immune system can be forced to respond. At some point there is an automatic dampening of the response which controls immunologic activities so as to protect the body from attack by its own destructive immune cells. Specific immunotherapy is being actively investigated. Particularly promising is the technique that involves the use of specific antibodies for types of tumor cells, which have been “loaded” with either antineoplastic drugs or radioactive materials. When injected into the bloodstream of a patient with that particular kind of tumor, the “loaded” antibodies attach to the surface of the malignant cells. Thus, the antineoplastic drug or radiation does more damage to the malignant cells than to nonmalignant cells that the antibody does not bind to. Adaptive immunotherapy is a technique in which a cancer patient's white blood cells are withdrawn and cultured in the laboratory with interleukin-2. The leukocytes thus treated are infused into the patient's bloodstream to stimulate the immune system. Immunotherapy is also used in the desensitization or hyposensitization of individuals allergic to specific allergens. Minute amounts of allergen to which the person is allergic are administered by injection in increasing doses over prolonged periods of time, in order to provoke production of large quantities of blocking antibody (predominantly IgG), which prevents an immediate hypersensitivity reaction from occurring. Presumably, the blocking antibody prevents the reaction by competing locally or in the circulation for the antigen. im·mu·no·ther·a·py(im'yū-nō-thār'ă-pē),This method has been widely adopted in oncology, particularly in cases that fail to respond to other treatment. Immunotherapy seeks to boost immune system function, as with the administration of interferons and interleukin-2, or to attack cancerous cells directly, as with the injection of monoclonal antibodies. Several alternative medical practices are claimed to enhance immune function, and various over-the-counter substances (for example, goldenseal, L-lysine) have gained popularity for this supposed property. immunotherapy(ĭm′yə-nō-thĕr′ə-pē, ĭ-myo͞o′-)immunotherapyAllergy medicineA therapy in which an allergen (e.g., hymenopteran venom) is administered in increasing doses to individuals who have potentially fatal hypersensitivity to an allergen. Immunotherapy elicits production of blocking IgG antibodies, interferes with antigen-Fab (a part of an immunoglobuln molecule) binding, prevents fixation of IgE a primary component of anaphylaxis), downregulates T-cell responses, inhibits inflammatory responses to allergens and attenuates anaphylactic reactions. Immunotherapy in patients with seasonal ragweed-exacerbated asthma and allergic rhinitis evokes objective improvement of symptoms, which may not be sustained over time. Oncology A therapy that nonspecifically stimulates the immune system to destroy malignant cells. Anecdotal success has been reported with BCG immunotherapy (in which BCG is instilled in the bladder to control superfical transitional cell carcinomas) in melanomas, leukaemia and solid tumours; Coley’s toxin; and heat-killed formalin-treated Corynebacterium parvum (an immunopotentiator and immunomodulator in animals that evokes reticuloendothelial hyperplasia, stimulation of macrophages and B cells and which may enhance T-cell function by increasing its blastogenic response to T-cell mitogens). immunotherapyBiological response modifier therapy, biological therapy, hyposensitization therapy Allergy medicineimmunotherapyimmunotherapytreatment involving the use of ANTIBODIES.Immunotherapyim·mu·no·ther·a·py(im'yū-nō-thār'ă-pē)immunotherapy
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