cell-mediated immunity

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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
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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 ?
Metzger, "Seasonal FluMist vaccination induces cross-reactive T cell immunity against H1N1 (2009) influenza and secondary bacterial infections," Journal of Immunology, vol.
Together, all these findings illustrate a biological function for IL17A in regulating Th1 cell immunity and host responses to intracellular pathogens (Figure 1).
Host-innate immunity in the gut is influenced by paneth cells and intestinal DCs which may be responsible for enhancing T cell immunity induced by checkpoint blockade [95, 96].
Lead author Professor Peter Doherty, from the University of Melbourne, said that predicting and designing vaccines to protect against such mutants can promote T cell immunity.
Cell immunity was evaluated at CD4 = 250 cells/[mm.sup.3], CD8 = 2,340 [mm.sup.3], as shown in Table 6.
Afferent phase production of TNF-alpha is required for the development of protective T cell immunity to Cryptococcus neoformans.
Reconstitution of CD4 cell immunity against varicella-zoster virus was apparent in the vaccinated patients.
Heeger, "Complement regulation of T cell immunity, " Immunologic Research, vol.
Lyke et al., "Live attenuated malaria vaccine designed to protect through hepatic [CD8.sup.+] T cell immunity," Science, vol.
Effects of green tea polyphenols on murine transplant-reactive T cell immunity. Clin Immunol.
According to the company, the secondary endpoints in the phase 1 trial include a determination of the recommended Phase 2 dose, an evaluation of T cell immunity markers and preliminary anti-tumor activity.