Search results for "Lectin"
showing 10 items of 495 documents
A role for Toll-like receptor mediated signals in neutrophils in the pathogenesis of the anti-phospholipid syndrome.
2012
The anti-phospholipid syndrome (APS) is characterized by recurrent thrombosis and occurrence of anti-phospholipid antibodies (aPL). aPL are necessary, but not sufficient for the clinical manifestations of APS. Growing evidence suggests a role of innate immune cells, in particular polymorphonuclear neutrophils (PMN) and Toll-like receptors (TLR) to be additionally involved. aPL activate endothelial cells and monocytes through a TLR4-dependent signalling pathway. Whether this is also relevant for PMN in a similar way is currently not known. To address this issue, we used purified PMN from healthy donors and stimulated them in the presence or absence of human monoclonal aPL and the TLR4 agonis…
Effect of Pro-inflammatory Stimuli on Tumor Cell-Mediated Induction of Endothelial Cell Adhesion Molecules in Vitro
2002
The object of our study was the question about the relevance of the tumor surrounding inflammatory cells with respect to the metastatic potential of the tumor cells. To imitate the role of inflammatory cells, three colon carcinoma (HT-29, HRT-18, and SW-620), one breast carcinoma (MCF-7), and one melanoma (ST-ML-12) cell lines were treated with pro-inflammatory stimuli, LPS, TNF-alpha, or IL-1beta. HUVEC monolayers were then stimulated by the collected supernatants (SN) of the tumor cells, following washing out of the applied stimuli. Analysis of CAM expression on HUVEC was performed using cell enzyme immunoassay. E-selectin, VCAM-1, and, in part, ICAM-1 were significantly up-regulated on H…
Endothelialization and Anticoagulation Potential of Surface-Modified PET Intended for Vascular Applications.
2018
In vascular tissue engineering, great attention is paid to the immobilization of biomolecules onto synthetic grafts to increase bio- and hemocompatibility-two critical milestones in the field. The surface modification field of poly(ethylene terephthalate) (PET), a well-known vascular-graft material, is matured and oversaturated. Nevertheless, most developed methods are laborious multistep procedures generally accompanied by coating instability or toxicity issues. Herein, a straightforward surface modification procedure is presented engineered to simultaneously promote surface endothelialization and anticoagulation properties via the covalent immobilization of gelatin through a photoactivate…
Resistance of natural killer T cell-deficient mice to systemic Shwartzman reaction.
2000
The generalized Shwartzman reaction in mice which had been primed and challenged with lipopolysaccharide (LPS) depends on interleukin (IL)-12-induced interferon (IFN)-gamma production at the priming stage. We examined the involvement in the priming mechanism of the unique population of Valpha14 natural killer T (NKT) cells because they promptly produce IFN-gamma after IL-12 stimulation. We report here that LPS- or IL-12-primed NKT cell genetically deficient mice were found to be resistant to LPS-elicited mortality. This outcome can be attributed to the reduction of IFN-gamma production, because injection of recombinant mouse IFN-gamma, but not injection of IL-12, effectively primed the NKT …
Ciona intestinalis galectin (CiLgals-a and CiLgals-b) genes are differentially expressed in endostyle zones and challenged by LPS
2015
Abstract Immunohistochemical and in situ hybridization assays were performed to answer the question whether the endostyle, that is the initial gastro-intestinal trait of Ciona intestinalis pharynx, is involved in galectin (CiLgals-a and CiLgals-b) production during the pharynx inflammatory response to LPS inoculation. Specific anti-CiLgal-a and anti-CiLgals-b antibodies, and oligonucleotide probes, that mark inflammatory hemocytes inside the pharynx vessels and vessel epithelium as shown by a previous paper, were assayed on endostyle histological sections. For the first time, we show that galectins are produced by endostyle zones, and both CiLgals-a and –b genes are upregulated by LPS. CiLg…
Application of X-ray microanalysis to study of the expression of endothelial adhesion molecules on human umbilical vein endothelial cells in vitro
1994
A semi-quantitative procedure is described, which allows the evaluation of expression levels of endothelial adhesion molecules on cultured human umbilical vein endothelial cells (HUVEC) using energy dispersive X-ray microanalysis (EDX). As a model two adhesion molecules, E-selection (CD62E; ELAM-1/endothelial leukocyte adhesion molecule-1) and ICAM-1 (intercellular adhesion molecule-1; CD54), were localized by the use of the silver-enhancement colloidal gold method after stimulation of HUVEC with endotoxin lipopolysaccharide (LPS), tumour necrosis factor (TNF) or a phorbol ester (PMA). The analysis was performed in a scanning electron microscope (SEM) at an accelerating voltage of 15 kV wit…
IL-10 down-regulates T cell activation by antigen-presenting liver sinusoidal endothelial cells through decreased antigen uptake via the mannose rece…
1998
SUMMARYOur study demonstrates that antigen-presenting liver sinusoidal endothelial cells (LSEC) induce production of interferon-gamma (IFN-γ) from cloned Th1 CD4+ T cells. We show that LSEC used the mannose receptor for antigen uptake, which further strengthened the role of LSEC as antigen-presenting cell (APC) population in the liver. The ability of LSEC to activate cloned CD4+ T cells antigen-specifically was down-regulated by exogenous prostaglandin E2 (PGE2) and by IL-10. We identify two separate mechanisms by which IL-10 down-regulated T cell activation through LSEC. IL-10 decreased the constitutive surface expression of MHC class II as well as of the accessory molecules CD80 and CD86 …
CD4+CD25+ regulatory T cells inhibit natural killer cell functions in a transforming growth factor-beta-dependent manner.
2007
Tumor growth promotes the expansion of CD4+CD25+ regulatory T (T reg) cells that counteract T cell–mediated immune responses. An inverse correlation between natural killer (NK) cell activation and T reg cell expansion in tumor-bearing patients, shown here, prompted us to address the role of T reg cells in controlling innate antitumor immunity. Our experiments indicate that human T reg cells expressed membrane-bound transforming growth factor (TGF)–β, which directly inhibited NK cell effector functions and down-regulated NKG2D receptors on the NK cell surface. Adoptive transfer of wild-type T reg cells but not TGF-β−/− T reg cells into nude mice suppressed NK cell–mediated cytotoxicity, redu…
Involvement of complement pathways in patients with bacterial septicemia.
2007
The complement system is a major humoral portion of the innate immune system, playing a significant role in host defence against microorganisms. The biological importance of this system is underlined by the fact that at least three different pathways for its activation exist, the classical, the MBL and the alternative pathway. To elucidate the involvement of the classical and/or the MBL pathway during bacterial septicemia, 32 patients with gram-positive and 30 patients with gram-negative bacterial infections were investigated. In patients with gram-positive bacteria, a significant consumption of C1q (p=0.005) but not of mannose-binding lectin (MBL) (p=0.2) was found during the acute phase o…
Sequential BMP7/TGF-β1 signaling and microbiota instruct mucosal Langerhans cell differentiation
2018
Capucha et al. demonstrate that mucosal Langerhans cell (LC) differentiation from pre–dendritic cells and monocytes involves consecutive BMP7 and TGF-β1 signaling in separate anatomical locations. Moreover, mucosal microbiota regulates the development of LCs that in turn shape microbial and immunological homeostasis.