cell-mediated immunity

(redirected from Cell mediated immunity)
Also found in: Dictionary, Encyclopedia.

cell-·me·di·at·ed im·mu·ni·ty (CMI),

, cellular immunity
Immune responses mediated by activated, antigen-specific T lymphocytes. These T cells may function as effector cells or may orchestrate propagation of the inflammatory response and cellular recruitment through their secretion of cytokines and chemokines.
Synonym(s): delayed hypersensitivity (1)
Farlex Partner Medical Dictionary © Farlex 2012

cell-mediated immunity

n.
Immunity resulting from a cell-mediated immune response. Also called cellular immunity.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

cell-me·di·at·ed im·mu·ni·ty

, cellular immunity (CMI) (sel'mē'dē-āt-ĕd i-myū'ni-tē, sel'yū-lăr)
Immune responses that are initiated by T lymphocytes and mediated by T lymphocytes, macrophages, or both (e.g., graft rejection, delayed-type hypersensitivity).
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
Enlarge picture
CELL-MEDIATED IMMUNITY

cell-mediated immunity

Abbreviation: CMI.
The regulatory and cytotoxic activities of T cells during the specific immune response. This process requires about 36 hr to reach its full effect. Synonym: T-cell–mediated immunity See: illustration; humoral immunity

Unlike B cells, T cells cannot recognize foreign antigens on their own. Foreign antigens are recognized by antigen-presenting cells (APCs) such as macrophages, which engulf them and display part of the antigens on the APC's surface next to a histocompatibility or “self-” antigen (macrophage processing). The presence of these two markers, plus the cytokine interleukin-1 (IL-1) secreted by the APCs activates CD4 helper T cells (TH cells), which regulate the activities of other cells involved in the immune response.

CMI includes direct lysis of target cells by cytotoxic T cells, creation of memory cells that trigger a rapid response when a foreign antigen is encountered for the second time, and delayed hypersensitivity to tissue and organ transplants. T cells also stimulate the activity of macrophages, B cells, and natural killer cells. These functions are controlled largely by the secretion of lymphokines such as the interleukins, interferons, and colony-stimulating factors. Lymphokines facilitate communication and proliferation of the cells in the immune system.

See also: immunity
Medical Dictionary, © 2009 Farlex and Partners

cell-mediated immunity

Action by the immune system involving T cells (T LYMPHOCYTES) and concerned with protection against viruses, fungi, TUBERCULOSIS and cancers and rejection of foreign grafted material. Cell-mediated immunity is not primarily effected by ANTIBODIES.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
Effects of colchicine on cell mediated immunity (CMI): Experimental animals: Albino mice (five-to-seven week-old) were purchased from Department of Theriogenolgy University of Veterinary and Animal Sciences (UVAS) Lahore.
In the present project ketoprofen effects on the phenomena of cell mediated immunity were studied.
High index of suspicion is warranted in patients with impaired cell mediated immunity, who present with fever of unknown origin and elevated liver function tests, especially if the patient has resided or visited an endemic area.
Cell mediated immunity and lower genital tract neoplasia.
Cell Mediated Immunity: Cell mediated immunity (CMI) was determined by employing dermis delayed type hypersensitivity (DHT) reaction (Tiwary and Goel, 1985).
Decreased cell mediated immunity in patients with non--insulin dependent diabetes mellitus Diabetes Res Clin Pract 1995; 28: 137-46.
These patients are immunologically distinct as they present with low or non existing T cell mediated immunity to antigens of M.
Cyclophosphamide induced neutropenia and delayed type hypersensitivity assays were performed to evaluate cell mediated immunity while the other two models were used to evaluate the effect of flurbiprofen on humoral immunity.
Protection is attained 4-6 weeks after BCG vaccination and is mainly due to cell mediated immunity. BCG vaccination site forms a small hypo pigmented scar 5-7 mm in size by 10-12 weeks.
The tuberculoid pole has good cell mediated immunity to M.leprae, with few lesions and bacilli while the lepromatous pole has poor immunity coupled with extensive involvement and greater bacillary load.