cell-mediated immunity

(redirected from Cell 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)

cell-mediated immunity

Immunity resulting from a cell-mediated immune response. Also called cellular immunity.

cell-mediated immunity

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).
Enlarge picture

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

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.


effected by cellular rather than chemical elements.

cell-mediated hypersensitivity
see delayed hypersensitivity.
cell-mediated immunity
see cellular immunity.
cell-mediated lympholysis assay
a test of cell-mediated immunity in which activated cytoxic T lymphocytes cause lysis of 51Cr-labeled target cells.
References in periodicals archive ?
The addition of this compound promoted significant generation of potent killer T cell immunity and provided protection from infection.
Researchers sought to demonstrate that a combination of gene therapy to insert a normal form of the IL2RG gene into patients' own stem cells and use of low-dose marrow conditioning to enhance engraftment of the patients' own gene-corrected stem cells would successfully restore both B cell immunity and antibody production.
While there is a growing understanding of the importance of T cell immunity in protecting against infectious diseases, genetic diversity and limitations in screening technology have made it challenging to identify antigens that would produce a protective immune response across a broad population in Chlamydia and other complex illnesses.
Further, the results confirmed that intratumoral generation of IL-12 and associated proteins lead to systemic anti-melanoma T cell immunity including cytotoxic CD8+ T cells and TH1 CD4+ cells, without any evidence of increased T regulatory cells or myeloid-derived suppressor cells.
Analysis of Phase 2 data evaluating induced memory T cell immunity following treatment with AGS-003 in combination with sunitinib presented at the 2013 Annual Meeting of the Society for Immunotherapy of Cancer (SITC).
Some vaccines also are directed against more or different types of HPV or are designed as therapeutic vaccines by induction of T cell immunity.
About Genocea Biosciences Genocea Biosciences is harnessing the power of T cell immunity to develop the next generation of vaccines.
The antigens were identified using ATLAS (TM), Genocea's platform for the rapid discovery of antigens that induce T cell immunity.
In contrast to conventional vaccines, Adamis' novel technology focuses on the induction of T cell immunity specifically directed at conserved, unchanging regions of the virus.
His laboratory research on cancer vaccines focuses on augmenting CD4 helper T cell immunity using peptide epitopes.
These results were presented today in a talk entitled "Induction of Potent T Cell Immunity in Macaques by EP DNA + Molecular Adjuvants" delivered by Professor David Weiner of the University of Pennsylvania School of Medicine.