Search results for "MAST CELLS"
showing 10 items of 99 documents
The Anti-apoptotic Murine Cytomegalovirus Protein vMIA-m38.5 Induces Mast Cell Degranulation.
2020
Mast cells (MC) represent "inbetweeners" of the immune system in that they are part of innate immunity by acting as first-line sentinels for environmental antigens but also provide a link to adaptive immunity by secretion of chemokines that recruit CD8 T cells to organ sites of infection. An interrelationship between MC and cytomegalovirus (CMV) has been a blank area in science until recently when the murine model revealed a role for MC in the resolution of pulmonary infection by murine CMV (mCMV). As to the mechanism, MC were identified as a target cell type of mCMV. Infected MC degranulate and synthesize the CC-chemokine ligand-5 (CCL-5), which is released to attract protective virus-spec…
Mesenchymal Transition of High-Grade Breast Carcinomas Depends on Extracellular Matrix Control of Myeloid Suppressor Cell Activity
2016
SummaryThe extracellular matrix (ECM) contributes to the biological and clinical heterogeneity of breast cancer, and different prognostic groups can be identified according to specific ECM signatures. In high-grade, but not low-grade, tumors, an ECM signature characterized by high SPARC expression (ECM3) identifies tumors with increased epithelial-to-mesenchymal transition (EMT), reduced treatment response, and poor prognosis. To better understand how this ECM3 signature is contributing to tumorigenesis, we expressed SPARC in isogenic cell lines and found that SPARC overexpression in tumor cells reduces their growth rate and induces EMT. SPARC expression also results in the formation of a h…
IL-33 promotes food anaphylaxis in epicutaneously sensitized mice by targeting mast cells
2016
Background Cutaneous exposure to food allergens predisposes to food allergy, which is commonly associated with atopic dermatitis (AD). Levels of the epithelial cytokine IL-33 are increased in skin lesions and serum of patients with AD. Mast cells (MCs) play a critical role in food-induced anaphylaxis and express the IL-33 receptor ST2. The role of IL-33 in patients with MC-dependent food anaphylaxis is unknown. Objective We sought to determine the role and mechanism of action of IL-33 in patients with food-induced anaphylaxis in a model of IgE-dependent food anaphylaxis elicited by oral challenge of epicutaneously sensitized mice. Methods Wild-type, ST2-deficient, and MC-deficient Kit W-sh/…
Interleukin-9 over-expression and T helper 9 polarization in systemic sclerosis patients.
2017
Summary T helper 9 (Th9) cells and interleukin (IL)-9 are involved in the pathogenesis of several autoimmune diseases. The exact role of IL-9 and Th9 cells in patients with systemic sclerosis (SSc) have not yet been studied adequately. IL-9, IL-9R, transcription factor PU.1 (PU.1), IL-4, thymic stromal lymphopoietin (TSLP) and transforming growth factor (TGF)-β expression were assessed in skin and kidney biopsies of SSc patients and healthy controls (HC) by immunohistochemistry (IHC). The cellular source of IL-9 was also analysed by confocal microscopy analysis. Peripheral IL-9-producing cells were also studied by flow cytometry. The functional relevance of IL-9 increased expression in SSc …
Activation of cutaneous immune responses in complex regional pain syndrome
2014
The pathogenesis of complex regional pain syndrome (CRPS) is unresolved, but tumor ne- crosis factor alpha (TNF-a) and interleukin-6 (IL-6) are elevated in experimental skin blister fluid from CRPS-affected limbs, as is tryptase, a marker for mast cells. In the rat fracture model of CRPS, exag- gerated sensory and sympathetic neural signaling stimulate keratinocyte and mast cell proliferation, causing the local production of high levels of inflammatory cytokines leading to pain behavior. The current investigation used CRPS patient skin biopsies to determine whether keratinocyte and mast cell proliferation occur in CRPS skin and to identify the cellular source of the up-regulated TNF-a, IL-6…
Pattern analysis of human cutaneous mast cell populations by total body surface mapping.
2003
SummaryBackground Mast cells (MCs), critical effector cells in allergic inflammation and innate immunity to bacteria, are located in large numbers in tissues that interface the external environment, including the skin. However, little is known about the distribution and numbers of human skin MCs. Objectives To assess the influence of age, sex and skin region on size and spatial distribution of MC populations in normal human skin. Methods Biopsies of healthy skin were obtained from 150 male and female individuals (age range 10–86 years). MCs were quantified and mapped planimetrically by histomorphometry in 15 anatomical sites (abdomen, thorax, lower and upper back, lower and upper arm, lower…
High density of tryptase-positive mast cells in human colorectal cancer: a poor prognostic factor related to protease-activated receptor 2 expression
2013
Tryptase(+) mast cells (MCs), abundant in the invasive front of tumours, contribute to tissue remodelling. Indeed, protease-activated receptor- 2 (PAR-2) activation by MC-tryptase is considered an oncogenic event in colorectal cancer (CRC). Recently, we have suggested NHERF1 as a potential new marker in CRC. In this study, we aimed to determine the distribution of tryptase(+) MCs and PAR-2 and to examine the relationship between PAR-2 and NHERF1, investigating their reputed usefulness as tumour markers. We studied a cohort of 115 CRC specimens including primary cancer (C) and adjacent normal mucosa (NM) by immunohistochemical double staining, analyzing the protein expression of MC-tryptase,…
Rituximab modulates IL-17 expression in the salivary glands of patients with primary Sjögren's syndrome.
2014
OBJECTIVE: The aim of this study was to evaluate the role of rituximab (RTX) in modulating the expression of the IL-17/IL-23 pathway in the salivary glands (SGs) of patients with primary SS (pSS). METHODS: Consecutive SG biopsies were obtained from 15 patients with pSS before and after 1 year of RTX therapy. The SG expression of IL-17, IL-23p19 and p-STAT3 was evaluated by immunohistochemistry at baseline and after RTX therapy. The role of mast cells in pSS patients in modulating the Th17 response and the immunologic effect of RTX on mast cells were also studied in in vitro experiments. RESULTS: IL-17 was overexpressed in the SGs of patients with pSS mainly by infiltrating T cells and mast …
Investigation into mechanisms mediating the inhibitory effect of 1,4-benzodiazepines on mast cells by gene expression profiling.
2013
Abstract Aims This study aims to identify by a molecular genetic approach potential targets in mast cells at which 1,4-benzodiazepines may cause their inhibitory effect on mast cell activity. Main methods Gene expression analyses with microarray gene chip and/or quantitative PCR were performed using 1,4-benzodiazepine-treated human mast cell leukemia HMC-1.2 cells, promyelocytic leukemia HL-60 cells and human mast cells from healthy volunteers and patients with mast cell activation disease (MCAD). Pathway analysis was applied to search for enriched biological functions and canonical pathways within differentially regulated genes. Key findings Both neoplastic and normal human mast cells expr…
Mast Cells Induce Migration of Dendritic Cells in a Murine Model of Acute Allergic Airway Disease
2009
<i>Background: </i>The migration of dendritic cells (DCs) from the lungs to the regional lymph nodes is necessary for the development of allergic airway disease. Following activation, mast cells release a variety of stored or de novo-produced inflammatory mediators, several of them being capable of activating DCs. In this study, the role of mast cells on DC migration from the lungs to the thoracic lymph nodes was investigated in sensitized mice. <i>Methods:</i> Mast cell-deficient mice (Kit<sup>W-sh/W-sh</sup>) and their wild-type counterparts were sensitized intraperitoneally with ovalbumine (OVA) in saline and challenged by a single intranasal administr…