J Biol Regul Homeost Agents
August 2014
Human mast cells (first described in 1879 by Paul Ehrlich) develop from committed precursors in the bone marrow expressing the differentiation marker CD34+ and distinct from the three other myeloid cells. Mast cells are present in various tissues especially near blood vessels, epithelia and nerves and they are activated by cross-linking of FcεRI, but also by a number of neuropeptides. NGF mediates a number of inflammatory and autoimmune states in conjunction with an increased accumulation of mast cells which appear to be involved in neuroimmune interactions and tissue inflammation.
View Article and Find Full Text PDFEstablishment of Leishmania infection inside macrophages requires deactivation of various signaling pathways that are dispensable for effective immune responses against the parasite. In the present study, we provide evidence that Leishmania infantum promastigotes attachment on the surface of peritoneal macrophages, internalization and transformation to amastigotes abrogated the activation of extracellular signal-regulated protein kinases (ERK) 1/2, p38 mitogen activated protein kinases (MAPK) and c-Jun NH2-terminal kinases (JNK) and the production of pro-inflammatory cytokines IL-12 and TNFalpha. Subsequent macrophage stimulation with lipopolysaccharide (LPS) during the first hours of exposure to parasite or infection resulted in restoration of MAPK phosphorylation.
View Article and Find Full Text PDFIt is well established that mast cells, which are found in the tissues in the proximity of small blood vessels and post-capillary venules, play a key role in the early phase of IgE-mediated allergic reactions. A greatly expanded understanding of the biology of IL-3 has emerged since the early 1980s. IL-3 is a specific factor that stimulates the growth of hematopoietic stem and progenitor cells of a variety of lineages and can promote the proliferation of certain classes of lymphocytes distinct from those that are dependent on IL-2.
View Article and Find Full Text PDFMast cells are ubiquitous in the body and multifunctional immune cells; they are known to be primary responders in allergic reactions, orchestrating strong responses to minute amounts of allergens. Mature mast cells perform important beneficial roles in host defense, both in IgE-dependent immune responses to certain parasites and in natural immunity to bacterial infection. In IgE-associated biological responses, the crosslinking of FcεRI-bound IgE with multivalent antigens initiate the activation of mast cells by promoting aggregation of FceRI.
View Article and Find Full Text PDFWhen through the skin a foreign antigen enters it provokes an immune response and inflammatory reaction. Mast cells are located around small vessels that are involved in vasaldilation. They mature under the influence of local tissue to various cytokines.
View Article and Find Full Text PDFAutoimmunity is a failure of self-tolerance resulting in immune reactions against autologous antigen. Rheumatoid arthritis is characterized by inflammation of synovium associated with destruction of the join cartilage and bone. A role of mast cell-mediated inflammation and antibodies are involved in this disease.
View Article and Find Full Text PDFMast cells are inflammatory cells, and they are prominent in inflammatory diseases such as allergy and asthma. Mast cells possess high-affinity receptors for IgE (FcERI) and the cross-linking of these receptors is essential to trigger the secretion of granules containing arachidonic acid metabolism (such as prostaglandin (PG) D2, leukotriene (LT) B4, and LTC4), histamine, cytokines, chemokines, and proteases, including mast cell-specific chymases and tryptases. Activation of mast cells provokes the secretion of cytokines and mediators that are responsible for the pathologic reaction of immediate hypersensitivity.
View Article and Find Full Text PDFCytokines serve as chemical communicators from one cell to another and most of them have pro-inflammatory activity. Mast cells have been recognised as important mediators of the pathogenesis of allergy and inflammation, suggesting a role for IL-33-mediated mast cell activation. IL-33 was recently identified as a ligand for the orphan IL-1 family receptor T1/ST2 and is mainly expressed by mast cells, fibroblasts, epithelial cells, and endothelial cells, particularly in high endothelial venules.
View Article and Find Full Text PDFCancer cells invade surrounding tissues and metastasize to distant sites. Diet high in fat is a strong link to, and perhaps causes, a high incidence of tumours. Trans-fatty acid might impair the function and it could be involved in the development of cancer.
View Article and Find Full Text PDFMast cells are granulated hematopoietic cells derived from stem cells that reside in nearly all tissues and are involved in protection of a host from bacterial infection with a protective and pathogenic activity. Mast cells are important for both innate and adaptive immunity in tissues which are in close contact with the environment. These cells express proinflammatory cytokines such as IL-1, IL-6, IL-8 and tumor necrosis factor which are necessary for innate immunity.
View Article and Find Full Text PDFMast cells play a central role in inflammatory and immediate allergic reactions and are necessary for allergic reactions. Mast cells play a role in the pathophysiology of autoimmune diseases and appear to be especially important in inflamed tissues, because they infiltrate tissues and produce a variety of cytokines. Mast cells are important for both innate and adaptive immunity in tissues that are in close contact with the environment, i.
View Article and Find Full Text PDFIt has been reported that high levels of cholesterol and triglycerides are associated with increased risk of developing atherosclerosis and shorter life. In fact, vascular endothelial dysfunction occurs during the human aging process. Accumulation of lipids in vascular endothelium activates leukocytes to produce cytokines and chemokines which recruit macrophages.
View Article and Find Full Text PDFThe link between low density lipoprotein and coronary heart disease has been widely studied. Oxidized LDL damages the artery wall, and a diet rich in vitamins and low in saturated fat and cholesterol may reduce this risk. Not only hypercholesterolemia but also low levels of high density lipoprotein cholesterol are critical risk factors for atherosclerosis and related diseases.
View Article and Find Full Text PDFNF-kappaB is implicated in lymphocyte development, maturation, proliferation and survival. This inducible transcription factor is widely expressed by virtually all cell types. In mammals, the genes rela, relb, crel, nfkappaΒ1, and nfkappaB encode the five NF-kB protein family members RelA (p65), RelB, c-Rel, p50, and p52, respectively, which form homo- and heterodimeric DNA-binding complexes capable of regulating target gene transcription of specific biological responses differentially.
View Article and Find Full Text PDFCulicoides biting midges (Diptera: Ceratopogonidae) were trapped between 1999 and 2004 at 122 locations in mainland Greece and on most of the larger Aegean and Ionian islands, using OVI light traps, in order to determine the distribution and seasonal activity of bluetongue virus vectors and other Culicoides species. Thirty-nine Culicoides species were identified, six of which (C. furcillatus, C.
View Article and Find Full Text PDFIn this study we investigate the effect of Trichinella spiralis vaccination on immune responses elicited in BALB/c mice challenged subcutaneously with 0.5 x 10 6 of Leishmania infantum promastigotes. Secretion of specific anti-L.
View Article and Find Full Text PDFInt J Immunopathol Pharmacol
September 2008
Hydatidosis is a usually asymptomatic chronic disease. In most patients who undergo surgery, hydatidosis is not resolved due to high recurrence rate. However, long-term treatment with albendazole has been found to have a significant efficacy that has been further improved when albendazole is combined with praziquantel and fat-rich diet.
View Article and Find Full Text PDFRegulated on activation, normal T-cell expressed and presumably secreted (RANTES), which generally mediates monocyte-macrophage (MO) activation and recruitment, is a protein of 8-10 kD that chemoattracts eosinophils, monocytes and certain T leukocyte subsets. RANTES is coded for by a gene cluster located on human chromosome 17 and is a human T-cell specific molecule. RANTES is a member of a beta intercrine subfamily reported to be a selective chemoattractant for human monocytes rather than neutrophils, and is also a chemoattractant for memory T lymphocytes, CD4+ cells.
View Article and Find Full Text PDFThe activation of monocytes/macrophages by several stimuli is an initial event in the inflammatory response. To ascertain the importance of LTB(4) and 5-lypoxigenase in the inflammatory site, we isolated and stimulated rat adherent granuloma macrophages (RAGMs) with calcium ionophore in the presence or absence of regulated on activation, normal T expressed and secreted (RANTES) [CCL5] at different concentrations. We tested the hypothesis that RANTES may influence the production of LTB(4) stimulated by calcium ionophore A23187 (2.
View Article and Find Full Text PDFActivation of cytokine receptors and alterations in cytokines are thought to play important roles in neuronal dysfunction and in the pathogenesis of the nervous system diseases. CXCL8 (IL-8) is a CXC chemokine with chemotactic and inflammatory properties. Chemokines control mast cell infiltration in several inflammatory diseases, including stress and neurological dysfunctions.
View Article and Find Full Text PDFFlavonoids are naturally occurring polyphenolic plant compounds that are capable of inhibiting histamine and cytokine release from several cells. Many studies suggest that flavonoids are anticancer agents with an apoptotic effect on tumor cells. Studies with animal tumour models have found vitamin deficiency to enhance susceptibility to chemical carcinogenesis and large doses of anti-oxidant vitamins and flavonoids to inhibit carcinogenesis.
View Article and Find Full Text PDFHost resistance against pathogens depends on a complex interplay of innate and adaptive immune mechanisms. Acting as an early line of defence, the immune system includes activation of neutrophils, tissue macrophages, monocytes, dendritic cells, eosinophils and natural killer (NK) cells. NK cells are lymphoid cells that can be activated without previous stimulation and are therefore like macrophages in the first line of defence against tumor cells and a diverse range of pathogens.
View Article and Find Full Text PDFJ Exp Clin Cancer Res
December 2006
Interleukins are mediators of inflammation, immunity and cancer. IL-15 is a cytokine produced by several leukocytes including phagocytes in response to infections and other signals that trigger innate immunity. IL-15 has many homologies to interleukin-2 (IL-2) and like IL-2, stimulates NK cells.
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