Lectins on antigen presenting cells are potentially involved in the antigen uptake and the cellular recognition and trafficking. Serial analysis of gene expression in monocyte-derived dendritic cells (DCs), monocytes, and macrophages revealed that 7 of the 19 C-type lectin mRNA were present in immature DCs. Two of these, the macrophage mannose receptor and the macrophage lectin specific for galactose/N-acetylgalactosamine (MGL), were found only in immature DCs, as confirmed by reverse transcriptase-PCR and flow cytometric analysis. By subcloning and sequencing the amplified mRNA, we obtained nucleotide sequences encoding seven different human MGL (hMGL) subtypes, which were apparently derived from alternatively spliced mRNA. In addition, the hMGL gene locus on human chromosome 17p13 contains one gene. A single nucleotide polymorphism was identified at a position in exon 3 that corresponds to the cytoplasmic region proximal to the transmembrane domain. Of all the splicing variants, the hMGL variant 6C was expressed at the highest levels on immature DCs from all donors tested. Immature DCs could incorporate ␣-GalNAc-modified soluble acrylamide polymers, and this was significantly inhibited by pretreatment of the cells with an anti-hMGL monoclonal antibody that blocks the lectin-carbohydrate interaction. We propose that hMGL is a marker of imDCs and that it functions as an endocytic receptor for glycosylated antigens. Dendritic cells (DCs)1 play a pivotal role in the immune system by processing and presenting a variety of antigens to T cells (1). The uptake of exogenous antigens is the first step in this process and is therefore a critical event that influences DC function. The uptake of glycoconjugates by DCs is potentially mediated by lectins, which are carbohydrate-binding proteins. There are at least four distinct lectin families in animal cells known as the C-type, S-type, P-type, and I-type lectins (2). Some lectins are known to participate in molecular and cellular trafficking in a manner that is dependent on the lectin type, its molecular architecture, and its subcellular localization. DCs are known to express a variety of lectins, particularly C-type lectins, but as yet their biological roles in DC function are unclear.How glycosylated antigen presentation is regulated and how this affects the subsequent immune responses has not yet been clarified. This is an important issue to investigate as it may improve our understanding of, for example, anti-tumor immunity to MUC1. MUC1 is a glycosylated membrane protein that frequently expresses truncated O-glycans such as the T (Gal1-3GalNAc-Thr/Ser) and Tn (GalNAc-Thr/Ser) antigens. MUC1 is an important candidate vaccine antigen as it is an antigen that is often overexpressed in solid tumors, including carcinoma of the breast, lung, pancreas, colon, and ovaries. MUC1-specific cytotoxic T lymphocytes have been isolated from draining lymph nodes of pancreatic and breast cancer patients, ascitic fluids of ovarian cancer patients, and peripheral blood mononuclear cell...
A theoretical answer to the controversial issue on the anomalous convective heat transfer in nanofluids has been provided, exploiting the Buongiorno model for convective heat transfer in nanofluids with modifications to fully account for the effects of nanoparticle volume fraction distributions on the continuity, momentum, and energy equations. A set of exact solutions have been obtained for hydrodynamically and thermally fully developed laminar nanofluid flows in channels and tubes, subject to constant heat flux. From the solutions, it has been concluded that the anomalous heat transfer rate, exceeding the rate expected from the increase in thermal conductivity, is possible in such cases as titania–water nanofluids in a channel, alumina–water nanofluids in a tube and also titania–water nanofluids in a tube. Moreover, the maximum Nusselt number based on the bulk mean nanofluid thermal conductivity is captured when the ratio of Brownian and thermophoretic diffusivities is around 0.5, which can be exploited for designing nanoparticles for high-energy carriers.
We studied the expression of a human macrophage lectin specific for galactose/N-acetylgalactosamine (hMGL) during macrophage differentiation. The expression of hMGL during the in vitro differentiation induced by human serum was examined by immunostaining and Western blotting with a specific mAb, MLD-1, as well as with RT-PCR analysis. hMGL was detected on cells at an intermediate stage of differentiation. These cells were round, slightly larger in size (12.7 +/- 0.2 microm) than monocytes (9.8 +/- 0.1 microm) and expressed the macrophage marker CD14, but lacked the dendritic cell marker CD1a. The highest levels of expression occurred after 2-4 days of culture. At this time point, MLD-1 prominently stained 20-40% of the cells. Monocytes cultured for 16 h or fully differentiated monocyte-derived macrophages were negative or weak for hMGL expression. Similar transient expression was also observed during granulocyte macrophage colony stimulating factor- or macrophage colony stimulating factor-dependent macrophage differentiation. The lectin was characterized as a functional endocytic receptor for glycosylated macromolecules, since the uptake of carbohydrate polymers was partially inhibited by the addition of MLD-1. The distribution of hMGL(+) cells in normal human skin was found by immunostaining to be mainly in the upper dermis distant from vascular structures. More than 90% of the hMGL(+) cells were double stained with anti-CD68 mAb and constituted approximately 20% of the CD68(+) cells. We suggest that the dermal hMGL(+) cells are a subset of differentiated cells derived from monocytes and that hMGL is a unique marker for cells at an intermediate stage of macrophage differentiation.
Acase of stomach carcinoma showing features of submucosal tumor is reported. The patient was a 50-year-old man presenting with hematemesis. Endoscopic examination was performed and revealed a submucosal tumor-like lesion with central ulceration in the fornix of the stomach. The biopsy specimen from this lesion showed poorly differentiated adenocarcinoma, and surgery was performed. The tumor, measuring 3.5 x 2.7 cm in size, invaded to the muscularis propria with proliferation of the interstitial connective tissue and lymphoid follicles consisting mainly of B lymphocytes in the submucosal layer. In situ hybridization of tumor tissue for Epstein-Barr virus (EBV)-encoded small RNA1 as target revealed negative results. In stomach carcinoma simulating submucosal tumor, as in this patient, preoperative diagnosis is important to plan treatment strategies.
The continuous resources recovery system utilizing the water electrolysis reaction was developed for recovering magnesium resources from seawater. A set of experiments for forming magnesium hydroxide from the deep-ocean water were carried out at a cathode channel separated by an ion exchange membrane. The ion concentrations of magnesium and calcium in the solution obtained from the outlet of channel were measured by ICP to evaluate the usefulness of the proposed method for the resources recovery system. Moreover, configuration and component in the precipitate formed in the proposed method were analyzed by SEM and EDS respectively. It was found that all magnesium contained in seawater can be precipitated by the proposed method. Moreover, the formation reaction of magnesium hydroxide depends on the quantity of electricity per unit volume of seawater since the production of OH− on the cathode electrode is proportional to the quantity of electricity in the water electrolysis reaction. Subsequently, the effect of deaeration from the deep-ocean water on the purity of magnesium hydroxide was investigated for forming pure magnesium hydroxide. It was found that 99% pure magnesium hydroxide can be created by applying deaeration to the deep-ocean water due to preventing formation of calcium carbonate since the carbon dioxide is removed from the seawater by deaeration.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.