activated macrophage

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ac·ti·vat·ed mac·ro·phage

a mature macrophage, in an active metabolic state, that is cytotoxic to tumor/target cells, usually following exposure to certain cytokines.
Synonym(s): armed macrophage

activated macrophage

A mononuclear phagocyte that has been “turned on”—i.e., has enhanced activity by cytokines. Activated macrophages (AMs) are twice the size of resting macrophages and more aggressive (increased lysozymes and surface expression of MHC class-II antigens), and are pivotal in defending a host against microorganisms that grow well within histiocytes/tissue-based macrophages and other cells—e.g., Listeria spp, and Salmonella spp.

activated macrophage

Immunology A mononuclear phagocyte that has been 'turned on'–ie has enhanced activity by cytokines; AMs are bigger–twice the size of resting macrophages and 'badder'–↑ lysozymes and surface expression of MHC class II antigens, and are pivotal in defending against microorganisms that grow well in histiocytes/tissue-based macrophages and other cells–eg, Listeria spp, and Salmonella spp


any of the large, mononuclear, highly phagocytic cells derived from bone marrow cells, promonocytes, the progeny of which, the monocytes, enter the bloodstream, where they stay for a few days before entering the tissues and developing into macrophages. They are components of the monocyte-macrophage system. Macrophages are usually immobile but become actively mobile when stimulated by inflammation, immune cytokines and microbial products. They are an important class of antigen presenting cells (APCs). See also immunity.

activated macrophage
under the influence of cytokines, particularly γ-interferon and interleukin 4, released by antigen-stimulated Th1 lymphocytes, resting macrophages are activated whereby they become larger, more motile, stickier, express more MHCII proteins on their surface, contain more lysosomes and lysosomal enzymes, and secrete a variety of substances including interleukin 1, tumor necrosis factors; they have increased phagocytic activity and increased killing via reactive oxygen intermediates, collagenases and lysosomal enzymes. Called also angry macrophage.
macrophage activating factor (MAF)
a lymphokine produced by T lymphocytes following in vitro, probably γ-interferon, antigenic stimulation that activates macrophages.
alveolar m's
rounded, granular, mononuclear phagocytes within the alveoli of the lungs that ingest inhaled particulate matter.
angry macrophage
see activated macrophage (above).
armed m's
those capable of inducing cytotoxicity as a consequence of binding antibodies via Fc receptors on their surfaces or by factors derived from T lymphocytes (specific macrophage arming factor [SMAF]).
macrophage chemotactic factor (MCF)
a lymphokine that attracts macrophages.
macrophage colony-stimulating factor
see colony-stimulating factors.
macrophage inhibition factor (MIF)
a lymphokine that inhibits macrophage migration, causing them to accumulate at the site of antigen.
specific macrophage arming factor (SMAF)
a lymphokine that stimulates macrophage cytotoxic activity.
References in periodicals archive ?
Interleukin-25 fails to activate STAT6 and induce alternatively activated macrophages.
Nachshon Knoller, Senior Neurosurgeon, Sheba Medical Center, Tel Hashomer, Israel, a principal investigator in this study commented, "In view of the impressive published preclinical results obtained with autologous activated macrophages, I am pleased to have performed the first such human procedure to test the safety of the technique.
Activated macrophages release various inflammatory cytokines that exacerbate the inflammatory response and cause tissue injury (Fujiwara and Kobayashi 2005).
To investigate the effect of stress on the phenotype of activated macrophages present at the wound site, gene expression of markers of wound healing macrophages (WHMs) (IGF-1 and CCL22), regulatory macrophages (RMs) (CCL1) and classically activated macrophages (CAMs) (CXCL-10 and CCL-5) were measured by RT-PCR in wounded tissue commencing from day 2 post-treatment.
Consistent with the study, several studies also suggested that ROS-induced maturation of macrophages is associated with upregulation of proinflammatory gene expression [82, 88], the hallmark of classically activated macrophages.
sup][16],[17] Activated macrophages in the injured kidney produce TNF-a and TGF-[sz], which are central mediators for renal fibrosis.
It should also be noted that a large number of activated macrophages undergo apoptosis, after which they release the lipid content into the matrix and form the lipid nucleus of atheromas [17].
HMGB1 is a ubiquitous nuclear protein that can be released by any damaged cell or by activated macrophages and certain other cell types.
YKL-40 promotes maturation of monocytes to macrophages; afterwards YKL-40 gets secreted by macrophages during the late stages of differentiation and eventually by the activated macrophages (12-15).
Galectin-3 is expressed by activated macrophages and induces cardiac fibroblasts to proliferate and deposit type I collagen in the myocardium (1).
Inflammation is a complex process regulated by a cascade of cytokines, growth factors, NO and prostaglandins produced by activated macrophages.
Hollzmuller et al (19), demonstrated that natural resistance to Leishmania infection depends on intracellular parasite killing by activated macrophages through production of L-arginine-nitric oxide metabolic pathway.

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