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Sample records for molecule-3-grabbing nonintegrin-related dc-signr

  1. Low expression of dendritic cell-specific intercellular adhesion molecule-grabbing nonintegrin-related protein in lung cancer and significant correlations with brain metastasis and natural killer cells.

    PubMed

    Liu, Xiaoli; Zhang, Hua; Su, Lijie; Yang, Peng; Xin, Zhiqiang; Zou, Junwei; Ren, Shuangyi; Zuo, Yunfei

    2015-09-01

    Dendritic cell-specific intercellular adhesion molecule-grabbing nonintegrin-related protein (DC-SIGNR) is a type II transmembrane protein which has been reported to bind a variety of pathogens as well as participate in immunoregulation. But the association between the level of DC-SIGNR and lung cancer is unknown. To investigate the clinical diagnostic significance of DC-SIGNR in lung cancer, we investigated serum DC-SIGNR levels in 173 lung cancer patients and 134 healthy individuals using enzyme-linked immunosorbent assay (ELISA). Results showed that serum DC-SIGNR levels in lung cancer patients were lower than that in healthy controls (P = 0.0003). A cut-off value of 3.8998 ng/L for DC-SIGNR predicted the presence of lung cancer with 78.03% sensitivity and 49.25% specificity (area under the curve = 0.6212, P = 0.0003). Strikingly, serum DC-SIGNR levels were significantly higher in lung cancer patients with brain metastasis compared to those without metastasis (P = 0.0283). Moreover, the serum concentrations of DC-SIGNR in lung cancer patients also correlated significantly with serum natural killer cells percentage (P = 0.0017). In addition, immunohistochemistry assay demonstrated that the expression of DC-SIGNR in lung tissues of 31 lung cancer patients and 13 tuberculosis patients was significantly lower than that in 18 normal lung tissues (P = 0.0418, 0.0289), and there is no significant difference between tuberculosis tissues and lung cancer tissues (P = 0.2696). These results suggest that DC-SIGNR maybe a promising biological molecule that has the potential for clinical research of lung cancer, whereas its underlying roles are needed to be investigated in further studies.

  2. Association of DC-SIGN and DC-SIGNR Repeat Regions with Susceptibility to Pulmonary Tuberculosis in Zahedan, Southeastern Iran.

    PubMed

    Naderi, Mohammad; Hashemi, Mohammad; Soroush, Navid; Amininia, Shadi; Taheri, Mohsen

    2016-05-01

    There are conflicting results concerning DC-SIGN and DC-SIGNR VNTR polymorphisms. The present study aimed to evaluate the possible association between DC-SIGN as well as DC-SIGNR VNTR polymorphisms and pulmonary tuberculosis (PTB) in a sample of Iranian population. This case-control study was done on 171 PTB and 161 healthy subjects. The variants were detected by polymerase chain reaction (PCR). DC-SIGNR VNTR genotypes in cases were 12.7% for 5/5, 2.4% for 6/5, 32.7% for 7/7, 38.2% for 7/5, 5.5% for 7/6, 1.2% for /5, 0.6% for 9/6, 6.7% for 9/7 in PTB patients and 19.7% for 5/5, 2.0% for 6/5, 31.6% for 7/7, 37.5% for 7/5, 5.7% for 7/6, 0.0% for 9/5, 0.7% for 9/6, 2.6% for 9/7 in controls. The findings showed no significant association between DC-SIGNR VNTR polymorphism and PTB. All subjects in cases and controls were 7/7 genotype regarding DC-SIGN VNTR polymorphism. Our data propose that DC-SIGNR VNTR, as well as DC-SIGN VNTR, were not associated with the risk of PTB in a sample of Iranian population. PMID:27309478

  3. Kaposi's sarcoma-associated herpesvirus K3 and K5 proteins down regulate both DC-SIGN and DC-SIGNR.

    PubMed

    Lang, Sabine M; Bynoe, Meisha O F; Karki, Roshan; Tartell, Michael A; Means, Robert E

    2013-01-01

    Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of multicentric Castleman's disease, primary effusion lymphoma and Kaposi's sarcoma. In this study, we show that like the C-type lectin DC-SIGN, the closely related DC-SIGNR can also enhance KSHV infection. Following infection, they are both targeted for down modulation and our data indicate that the KSHV MARCH-family ubiquitin ligase K5 is mediating this regulation and subsequent targeting for degradation of DC-SIGN and DC-SIGNR in the context of the virus. The closely related viral K3 protein, is also able to target these lectins in exogenous expressions studies, but only weakly during viral infection. In addition to requiring a functional RING-CH domain, several protein trafficking motifs in the C-terminal region of both K3 and K5 are important in regulation of DC-SIGN and DC-SIGNR. Further exploration of this modulation revealed that DC-SIGN is endocytosed from the cell surface in THP-1 monocytes, but degraded from an internal location with minimal endocytosis in HEK-293 cells. Pull-down data indicate that both K3 and K5 preferentially associate with immature forms of the lectins, mediating their ubiquitylation and degradation. Together, these data emphasize the molecular complexities of K3 and K5, while expanding the repertoire of targets of these two viral proteins. PMID:23460925

  4. Vitamin C Attenuates Hemorrhagic Shock-induced Dendritic Cell-specific Intercellular Adhesion Molecule 3-grabbing Nonintegrin Expression in Tubular Epithelial Cells and Renal Injury in Rats

    PubMed Central

    Ma, Li; Fei, Jian; Chen, Ying; Zhao, Bing; Yang, Zhi-Tao; Wang, Lu; Sheng, Hui-Qiu; Chen, Er-Zhen; Mao, En-Qiang

    2016-01-01

    Background: The expression of dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) in renal tubular epithelial cells has been thought to be highly correlated with the occurrence of several kidney diseases, but whether it takes place in renal tissues during hemorrhagic shock (HS) is unknown. The present study aimed to investigate this phenomenon and the inhibitory effect of Vitamin C (VitC). Methods: A Sprague–Dawley rat HS model was established in vivo in this study. The expression level and location of DC-SIGN were observed in kidneys. Also, the degree of histological damage, the concentrations of tumor necrosis factor-α and interleukin-6 in the renal tissues, and the serum concentration of blood urea nitrogen and creatinine at different times (2–24 h) after HS (six rats in each group), with or without VitC treatment before resuscitation, were evaluated. Results: HS induced DC-SIGN expression in rat tubular epithelial cells. The proinflammatory cytokine concentration, histological damage scores, and functional injury of kidneys had increased. All these phenomena induced by HS were relieved when the rats were treated with VitC before resuscitation. Conclusions: The results of the present study illustrated that HS could induce tubular epithelial cells expressing DC-SIGN, and the levels of proinflammatory cytokines in the kidney tissues improved correspondingly. The results also indicated that VitC could suppress the DC-SIGN expression in the tubular epithelial cells induced by HS and alleviate the inflammation and functional injury in the kidney. PMID:27411463

  5. Dendritic cell-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) recognizes a novel ligand, Mac-2-binding protein, characteristically expressed on human colorectal carcinomas.

    PubMed

    Nonaka, Motohiro; Ma, Bruce Yong; Imaeda, Hirotsugu; Kawabe, Keiko; Kawasaki, Nobuko; Hodohara, Keiko; Kawasaki, Nana; Andoh, Akira; Fujiyama, Yoshihide; Kawasaki, Toshisuke

    2011-06-24

    Dendritic cell (DC)-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) is a type II transmembrane C-type lectin expressed on DCs such as myeloid DCs and monocyte-derived DCs (MoDCs). Recently, we have reported that DC-SIGN interacts with carcinoembryonic antigen (CEA) expressed on colorectal carcinoma cells. CEA is one of the most widely used tumor markers for gastrointestinal cancers such as colorectal cancer. On the other hand, other groups have reported that the level of Mac-2-binding protein (Mac-2BP) increases in patients with pancreatic, breast, and lung cancers, virus infections such as human immunodeficiency virus and hepatitis C virus, and autoimmune diseases. Here, we first identified Mac-2BP expressed on several colorectal carcinoma cell lines as a novel DC-SIGN ligand through affinity chromatography and mass spectrometry. Interestingly, we found that DC-SIGN selectively recognizes Mac-2BP derived from some colorectal carcinomas but not from the other ones. Furthermore, we found that the α1-3,4-fucose moieties of Le glycans expressed on DC-SIGN-binding Mac-2BP were important for recognition. DC-SIGN-dependent cellular interactions between immature MoDCs and colorectal carcinoma cells significantly inhibited MoDC functional maturation, suggesting that Mac-2BP may provide a tolerogenic microenvironment for colorectal carcinoma cells through DC-SIGN-dependent recognition. Importantly, Mac-2BP was detected as a predominant DC-SIGN ligand expressed on some primary colorectal cancer tissues from certain parts of patients in comparison with CEA from other parts, suggesting that DC-SIGN-binding Mac-2BP bearing tumor-associated Le glycans may become a novel potential colorectal cancer biomarker for some patients instead of CEA.

  6. Impact of viral attachment factor expression on antibody-mediated neutralization of flaviviruses.

    PubMed

    Obara, Christopher J; Dowd, Kimberly A; Ledgerwood, Julie E; Pierson, Theodore C

    2013-03-01

    Neutralization of flaviviruses requires engagement of the virion by antibodies with a stoichiometry that exceeds a required threshold. Factors that modulate the number of antibodies bound to an individual virion when it contacts target cells impact neutralization potency. However, the contribution of cellular factors to the potency of neutralizing antibodies has not been explored systematically. Here we investigate the relationship between expression level of a viral attachment factor on cells and the neutralizing potency of antibodies. Analysis of the attachment factor DC-SIGNR on cells in neutralization studies failed to identify a correlation between DC-SIGNR expression and antibody-mediated protection. Furthermore, neutralization potency was equivalent on a novel Jurkat cell line induced to express DC-SIGNR at varying levels. Finally, blocking virus-attachment factor interactions had no impact on neutralization activity. Altogether, our studies suggest that cellular attachment factor expression is not a significant contributor to the potency of neutralizing antibodies to flaviviruses.

  7. Mannosyl Glycodendritic Structure Inhibits DC-SIGN-Mediated Ebola Virus Infection in cis and in trans

    PubMed Central

    Lasala, Fátima; Arce, Eva; Otero, Joaquín R.; Rojo, Javier; Delgado, Rafael

    2003-01-01

    We have designed a glycodendritic structure, BH30sucMan, that blocks the interaction between dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) and Ebola virus (EBOV) envelope. BH30sucMan inhibits DC-SIGN-mediated EBOV infection at nanomolar concentrations. BH30sucMan may counteract important steps of the infective process of EBOV and, potentially, of microorganisms shown to exploit DC-SIGN for cell entry and infection. PMID:14638512

  8. Generation and characterization of β1,2-gluco-oligosaccharide probes from Brucella abortus cyclic β-glucan and their recognition by C-type lectins of the immune system

    PubMed Central

    Zhang, Hongtao; Palma, Angelina S; Zhang, Yibing; Childs, Robert A; Liu, Yan; Mitchell, Daniel A; Guidolin, Leticia S; Weigel, Wilfried; Mulloy, Barbara; Ciocchini, Andrés E; Feizi, Ten; Chai, Wengang

    2016-01-01

    The β1,2-glucans produced by bacteria are important in invasion, survival and immunomodulation in infected hosts be they mammals or plants. However, there has been a lack of information on proteins which recognize these molecules. This is partly due to the extremely limited availability of the sequence-defined oligosaccharides and derived probes for use in the study of their interactions. Here we have used the cyclic β1,2-glucan (CβG) of the bacterial pathogen Brucella abortus, after removal of succinyl side chains, to prepare linearized oligosaccharides which were used to generate microarrays. We describe optimized conditions for partial depolymerization of the cyclic glucan by acid hydrolysis and conversion of the β1,2-gluco-oligosaccharides, with degrees of polymerization 2–13, to neoglycolipids for the purpose of generating microarrays. By microarray analyses, we show that the C-type lectin receptor DC-SIGNR, like the closely related DC-SIGN we investigated earlier, binds to the β1,2-gluco-oligosaccharides, as does the soluble immune effector serum mannose-binding protein. Exploratory studies with DC-SIGN are suggestive of the recognition also of the intact CβG by this receptor. These findings open the way to unravelling mechanisms of immunomodulation mediated by β1,2-glucans in mammalian systems. PMID:27053576

  9. Gut commensal microvesicles reproduce parent bacterial signals to host immune and enteric nervous systems.

    PubMed

    Al-Nedawi, Khalid; Mian, M Firoz; Hossain, Nazia; Karimi, Khalil; Mao, Yu-Kang; Forsythe, Paul; Min, Kevin K; Stanisz, Andrew M; Kunze, Wolfgang A; Bienenstock, John

    2015-02-01

    Ingestion of a commensal bacteria, Lactobacillus rhamnosus JB-1, has potent immunoregulatory effects, and changes nerve-dependent colon migrating motor complexes (MMCs), enteric nerve function, and behavior. How these alterations occur is unknown. JB-1 microvesicles (MVs) are enriched for heat shock protein components such as chaperonin 60 heat-shock protein isolated from Escherichia coli (GroEL) and reproduce regulatory and neuronal effects in vitro and in vivo. Ingested labeled MVs were detected in murine Peyer's patch (PP) dendritic cells (DCs) within 18 h. After 3 d, PP and mesenteric lymph node DCs assumed a regulatory phenotype and increased functional regulatory CD4(+)25(+)Foxp3+ T cells. JB-1, MVs, and GroEL similarly induced phenotypic change in cocultured DCs via multiple pathways including C-type lectin receptors specific intercellular adhesion molecule-3 grabbing non-integrin-related 1 and Dectin-1, as well as TLR-2 and -9. JB-1 and MVs also decreased the amplitude of neuronally dependent MMCs in an ex vivo model of peristalsis. Gut epithelial, but not direct neuronal application of, MVs, replicated functional effects of JB-1 on in situ patch-clamped enteric neurons. GroEL and anti-TLR-2 were without effect in this system, suggesting the importance of epithelium neuron signaling and discrimination between pathways for bacteria-neuron and -immune communication. Together these results offer a mechanistic explanation of how Gram-positive commensals and probiotics may influence the host's immune and nervous systems.

  10. Host Langerin (CD207) is a receptor for Yersinia pestis phagocytosis and promotes dissemination

    PubMed Central

    Yang, Kun; Park, Chae G; Cheong, Cheolho; Bulgheresi, Silvia; Zhang, Shusheng; Zhang, Pei; He, Yingxia; Jiang, Lingyu; Huang, Hongping; Ding, Honghui; Wu, Yiping; Wang, Shaogang; Zhang, Lin; Li, Anyi; Xia, Lianxu; Bartra, Sara S; Plano, Gregory V; Skurnik, Mikael; Klena, John D; Chen, Tie

    2015-01-01

    Yersinia pestis is a Gram-negative bacterium that causes plague. After Y. pestis overcomes the skin barrier, it encounters antigen-presenting cells (APCs), such as Langerhans and dendritic cells. They transport the bacteria from the skin to the lymph nodes. However, the molecular mechanisms involved in bacterial transmission are unclear. Langerhans cells (LCs) express Langerin (CD207), a calcium-dependent (C-type) lectin. Furthermore, Y. pestis possesses exposed core oligosaccharides. In this study, we show that Y. pestis invades LCs and Langerin-expressing transfectants. However, when the bacterial core oligosaccharides are shielded or truncated, Y. pestis propensity to invade Langerhans and Langerin-expressing cells decreases. Moreover, the interaction of Y. pestis with Langerin-expressing transfectants is inhibited by purified Langerin, a DC-SIGN (DC-specific intercellular adhesion molecule 3 grabbing nonintegrin)-like molecule, an anti-CD207 antibody, purified core oligosaccharides and several oligosaccharides. Furthermore, covering core oligosaccharides reduces the mortality associated with murine infection by adversely affecting the transmission of Y. pestis to lymph nodes. These results demonstrate that direct interaction of core oligosaccharides with Langerin facilitates the invasion of LCs by Y. pestis. Therefore, Langerin-mediated binding of Y. pestis to APCs may promote its dissemination and infection. PMID:25829141

  11. The Consequences of Multiple Simultaneous C-Type Lectin–Ligand Interactions: DCIR Alters the Endo-Lysosomal Routing of DC-SIGN

    PubMed Central

    García-Vallejo, Juan J.; Bloem, Karien; Knippels, Léon M. J.; Garssen, Johan; van Vliet, Sandra J.; van Kooyk, Yvette

    2015-01-01

    Antigen-presenting cells (APCs) are equipped with multiple receptors to allow proper pathogen recognition and capture. C-type lectin receptors (CLRs) recognize glycan structures on pathogens and endogenous glycoproteins for internalization and antigen processing and presentation. Often, the glycan specificity of these receptors is overlapping and/or pathogens are decorated with ligands for multiple CLRs, posing the question whether interference or cooperativity within the CLR family exists. Here, we used imaging flow cytometry to investigate the internalization properties of four different CLRs [mannose receptor, DC-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN), macrophage galactose-type lectin, and dendritic cell immunoreceptor (DCIR)] on different APCs, as well as their intracellular routing. Although the internalization score of the investigated CLRs was similar on monocytes, macrophages, and dendritic cells (DCs), DCIR internalization rates were lower compared to the other CLRs. Upon triggering, DCIR routed to intracellular compartments outside of the classical endo-lysosomal pathway, resulting in poor CD4+ T-cell stimulation. Although DC maturation reduced CLR expression levels, it did not affect their internalization rates. Although CLR internalization appeared to be independently regulated, DC-SIGN routing was affected when DCIR was triggered simultaneously. In conclusion, our results provide new insights for the design of DC-based immunotherapeutic strategies and suggest that DCIR is an inferior target in this respect. PMID:25806031

  12. Dendritic cells respond to nasopharygeal carcinoma cells through annexin A2-recognizing DC-SIGN

    PubMed Central

    Cheng, Chao-Wen; Hsu, Tin-Jui; Lin, Yun-Tien; Lai, Chang-Hao; Liao, Chen-Chung; Chen, Wei-Yu; Leung, Ting-Kai; Lee, Fei-Peng; Lin, Yung-Feng; Chen, Chien-Ho

    2015-01-01

    Dendritic cells (DCs) play an essential role in immunity and are used in cancer immunotherapy. However, these cells can be tuned by tumors with immunosuppressive responses. DC-specific intercellular adhesion molecule 3-Grabbing Nonintegrin (DC-SIGN), a C-type lectin expressed on DCs, recognizes certain carbohydrate structures which can be found on cancer cells. Nasopharyngeal carcinoma (NPC) is an epithelial cell-derived malignant tumor, in which immune response remains unclear. This research is to reveal the molecular link on NPC cells that induces the immunosuppressive responses in DCs. In this article, we report identification of annexin A2 (ANXA2) on NPC cells as a ligand for DC-SIGN on DCs. N-linked mannose-rich glycan on ANXA2 may mediate the interaction. ANXA2 was abundantly expressed in NPC, and knockdown of ANXA2 suppressed NPC xenograft in mice, suggesting a crucial role of ANXA2 in NPC growth. Interaction with NPC cells caused DC-SIGN activation in DCs. Consequently DC maturation and the proinflammatory interleukin (IL)-12 production were inhibited, and the immunosuppressive IL-10 production was promoted. Blockage of either DC-SIGN or ANXA2 eliminated the production of IL-10 from DCs. This report suggests that suppression of ANXA2 at its expression or glycosylation on NPC may improve DC-mediated immunotherapy for the tumor. PMID:25402728

  13. Synthesis and microarray-assisted binding studies of core xylose and fucose containing N-glycans.

    PubMed

    Brzezicka, Katarzyna; Echeverria, Begoña; Serna, Sonia; van Diepen, Angela; Hokke, Cornelis H; Reichardt, Niels-Christian

    2015-05-15

    The synthesis of a collection of 33 xylosylated and core-fucosylated N-glycans found only in nonmammalian organisms such as plants and parasitic helminths has been achieved by employing a highly convergent chemo-enzymatic approach. The influence of these core modifications on the interaction with plant lectins, with the human lectin DC-SIGN (Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Nonintegrin), and with serum antibodies from schistosome-infected individuals was studied. Core xylosylation markedly reduced or completely abolished binding to several mannose-binding plant lectins and to DC-SIGN, a C-type lectin receptor present on antigen presenting cells. Employing the synthetic collection of core-fucosylated and core-xylosylated N-glycans in the context of a larger glycan array including structures lacking these core modifications, we were able to dissect core xylose and core fucose specific antiglycan antibody responses in S. mansoni infection sera, and we observed clear and immunologically relevant differences between children and adult groups infected with this parasite. The work presented here suggests that, quite similar to bisecting N-acetylglucosamine, core xylose distorts the conformation of the unsubstituted glycan, with important implications for the immunogenicity and protein binding properties of complex N-glycans.

  14. Weak Ergodicity Breaking of Receptor Motion in Living Cells Stemming from Random Diffusivity

    NASA Astrophysics Data System (ADS)

    Manzo, Carlo; Torreno-Pina, Juan A.; Massignan, Pietro; Lapeyre, Gerald J.; Lewenstein, Maciej; Garcia Parajo, Maria F.

    2015-01-01

    Molecular transport in living systems regulates numerous processes underlying biological function. Although many cellular components exhibit anomalous diffusion, only recently has the subdiffusive motion been associated with nonergodic behavior. These findings have stimulated new questions for their implications in statistical mechanics and cell biology. Is nonergodicity a common strategy shared by living systems? Which physical mechanisms generate it? What are its implications for biological function? Here, we use single-particle tracking to demonstrate that the motion of dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN), a receptor with unique pathogen-recognition capabilities, reveals nonergodic subdiffusion on living-cell membranes In contrast to previous studies, this behavior is incompatible with transient immobilization, and, therefore, it cannot be interpreted according to continuous-time random-walk theory. We show that the receptor undergoes changes of diffusivity, consistent with the current view of the cell membrane as a highly dynamic and diverse environment. Simulations based on a model of an ordinary random walk in complex media quantitatively reproduce all our observations, pointing toward diffusion heterogeneity as the cause of DC-SIGN behavior. By studying different receptor mutants, we further correlate receptor motion to its molecular structure, thus establishing a strong link between nonergodicity and biological function. These results underscore the role of disorder in cell membranes and its connection with function regulation. Because of its generality, our approach offers a framework to interpret anomalous transport in other complex media where dynamic heterogeneity might play a major role, such as those found, e.g., in soft condensed matter, geology, and ecology.

  15. A Molecular Approach Designed to Limit the Replication of Mature DENV2 in Host Cells

    PubMed Central

    Jamal, Muhsin; Zaidi, Najam Us Sahar Sadaf

    2015-01-01

    Abstract Dengue virus (DENV) is an arthropod-borne virus, which belongs to the Flaviviridae family, and completes its life cycle in two hosts: humans and mosquitoes. For DENV maturation, the surface pre-membrane (prM) protein is cleaved to form a mature membrane protein (M) by furin, which is a cellular enzyme subsequently releasing the mature virus from the host dendritic cell. The objective of the current study was to inhibit mature DENV isotype 2 (DENV2) by RNA-interference in a Vero-81 cell line. Mature DENV2 was propagated in and isolated from U937 cells expressing dendritic cell-specific intracellular adhesion molecule-3-grabbing non-integrin. Maturation of DENV2 was confirmed by Western blot analysis, where virus stock lacking prM was considered mature. Inhibition studies were carried out by transfection of Vero-81 cells with six synthetic siRNAs along with a control siRNA. Reduction in cellular DENV2 was observed also by focus-reduction assay, immunofluorescence assay (IFA), and real-time quantitative polymerase chain reaction (RT-qPCR). Cells transfected with DENV2SsiRNA2, which was targeting the structural region M of mature DENV2, was able to reduce DENV2 titer by up to 85% in focus reduction assays. A significant reduction in mature DENV2 RNA load was observed by RT-qPCR, confirming the previous findings. IFA also revealed reduced levels of cellular DENV2. These results demonstrated that mature DENV2 can be effectively inhibited by synthetic siRNA targeting the structural region of the genome. Mature DENV2 can be successfully inhibited by siRNAs, and specifically high knock-down efficiency is observed by siRNAs against M region of mature DENV2. This study shows that M represents a potential target for RNAi based inhibitory approaches. PMID:26154890

  16. MicroRNA Expression Profiles of Human Blood Monocyte-derived Dendritic Cells and Macrophages Reveal miR-511 as Putative Positive Regulator of Toll-like Receptor 4*

    PubMed Central

    Tserel, Liina; Runnel, Toomas; Kisand, Kai; Pihlap, Maire; Bakhoff, Lairi; Kolde, Raivo; Peterson, Hedi; Vilo, Jaak; Peterson, Pärt; Rebane, Ana

    2011-01-01

    Dendritic cells (DCs) and macrophages (MFs) are important multifunctional immune cells. Like other cell types, they express hundreds of different microRNAs (miRNAs) that are recently discovered post-transcriptional regulators of gene expression. Here we present updated miRNA expression profiles of monocytes, DCs and MFs. Compared with monocytes, ∼50 miRNAs were found to be differentially expressed in immature and mature DCs or MFs, with major expression changes occurring during the differentiation. Knockdown of DICER1, a protein needed for miRNA biosynthesis, led to lower DC-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) and enhanced CD14 protein levels, confirming the importance of miRNAs in DC differentiation in general. Inhibition of the two most highly up-regulated miRNAs, miR-511 and miR-99b, also resulted in reduced DC-SIGN level. Prediction of miRNA-511 targets revealed a number of genes with known immune functions, of which TLR4 and CD80 were validated using inhibition of miR-511 in DCs and luciferase assays in HEK293 cells. Interestingly, under the cell cycle arrest conditions, miR-511 seems to function as a positive regulator of TLR4. In conclusion, we have identified miR-511 as a novel potent modulator of human immune response. In addition, our data highlight that miRNA influence on gene expression is dependent on the cellular environment. PMID:21646346

  17. The relationship of interacting immunological components in dengue pathogenesis.

    PubMed

    Nielsen, David G

    2009-01-01

    The World Health Organization (WHO) estimates that there are over 50 million cases of dengue fever reported annually and approximately 2.5 billion people are at risk. Mild dengue fever presents with headache, fever, rash, myalgia, osteogenic pain, and lethargy. Severe disease can manifest as dengue shock syndrome (DSS) or dengue hemorrhagic fever (DHF). Symptoms of DSS/DHF are leukopenia, low blood volume and pressure encephalitis, cold and sweaty skin, gastrointestinal bleeding, and spontaneous bleeding from gums and nose. Currently, there are no therapeutics available beyond supportive care and untreated complicated dengue fever can have a 50% mortality rate. According to WHO DSS/DHF is the leading cause of childhood mortality in some Asian countries. Dendritic cells are professional antigen presenting cells that are primary targets in a dengue infection. Dengue binds to Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin (DC-SIGN). DC-SIGN has a high affinity for ICAM3 which is expressed in activating T-cells. Previous studies have demonstrated an altered T-cell phenotype expressed in dengue infected patients that could be potentially mediated by dengue-infected DCs.Dengue is enhanced by three interacting components of the immune system. Dengue begins by infecting dendritic cells which in immature dendritic cells is mediated by DC-SIGN. In mature dendritic cells, antibodies can enhance dengue infection via Fc receptors. Downstream of dendritic cells T-cells become activated and generate the very cytokines implicated in vascular leak and shock in addition to activating effector cells. Both the virus and the antibodies are involved in release of complement and anaphylatoxins which can cause or exacerbate DHF/DSS. These systems are inextricable and strongly associated with dengue pathogenesis.

  18. Dermal CD14(+) Dendritic Cell and Macrophage Infection by Dengue Virus Is Stimulated by Interleukin-4.

    PubMed

    Schaeffer, Evelyne; Flacher, Vincent; Papageorgiou, Vasiliki; Decossas, Marion; Fauny, Jean-Daniel; Krämer, Melanie; Mueller, Christopher G

    2015-07-01

    Dengue virus (DENV) is responsible for the most prevalent arthropod-borne viral infection in humans. Events decisive for disease development occur in the skin after virus inoculation by the mosquito. Yet, the role of human dermis-resident immune cells in dengue infection and disease remains elusive. Here we investigated how dermal dendritic cells (dDCs) and macrophages (dMs) react to DENV and impact on immunopathology. We show that both CD1c(+) and CD14(+) dDC subsets were infected, but viral load greatly increased in CD14(+) dDCs upon IL-4 stimulation, which correlated with upregulation of virus-binding lectins Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Nonintegrin (DC-SIGN/CD209) and mannose receptor (CD206). IL-4 also enhanced T-cell activation by dDCs, which was further increased upon dengue infection. dMs purified from digested dermis were initially poorly infected but actively replicated the virus and produced TNF-α upon lectin upregulation in response to IL-4. DC-SIGN(+) cells are abundant in inflammatory skin with scabies infection or Th2-type dermatitis, suggesting that skin reactions to mosquito bites heighten the risk of infection and subsequent immunopathology. Our data identify dDCs and dMs as primary arbovirus target cells in humans and suggest that dDCs initiate a potent virus-directed T-cell response, whereas dMs fuel the inflammatory cascade characteristic of dengue fever. PMID:25521455

  19. Dengue virus binding and replication by platelets.

    PubMed

    Simon, Ayo Y; Sutherland, Michael R; Pryzdial, Edward L G

    2015-07-16

    Dengue virus (DENV) infection causes ∼200 million cases of severe flulike illness annually, escalating to life-threatening hemorrhagic fever or shock syndrome in ∼500,000. Although thrombocytopenia is typical of both mild and severe diseases, the mechanism triggering platelet reduction is incompletely understood. As a probable initiating event, direct purified DENV-platelet binding was followed in the current study by quantitative reverse transcription-polymerase chain reaction and confirmed antigenically. Approximately 800 viruses specifically bound per platelet at 37°C. Fewer sites were observed at 25°C, the blood bank storage temperature (∼350 sites), or 4°C, known to attenuate virus cell entry (∼200 sites). Dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) and heparan sulfate proteoglycan were implicated as coreceptors because only the combination of anti-DC-SIGN and low-molecular-weight heparin prevented binding. Interestingly, at 37°C and 25°C, platelets replicated the positive sense single-stranded RNA genome of DENV by up to ∼4-fold over 7 days. Further time course experiments demonstrated production of viral NS1 protein, which is known to be highly antigenic in patient serum. The infectivity of DENV intrinsically decayed in vitro, which was moderated by platelet-mediated generation of viable progeny. This was shown using a transcription inhibitor and confirmed by freeze-denatured platelets being incapable of replicating the DENV genome. For the first time, these data demonstrate that platelets directly bind DENV saturably and produce infectious virus. Thus, expression of antigen encoded by DENV is a novel consideration in the pathogen-induced thrombocytopenia mechanism. These results furthermore draw attention to the possibility that platelets may produce permissive RNA viruses in addition to DENV.

  20. SARS-CoV Replication and Pathogenesis in an In Vitro Model of the Human Conducting Airway Epithelium

    PubMed Central

    Sims, Amy C.; Burkett, Susan E.; Yount, Boyd; Pickles, Raymond J.

    2008-01-01

    inoculation and progeny virion egress in both polarized Calu3 and ciliated cells of HAE was the apical surface suggesting mechanisms to release large quantities of virus into the lumen of the human lung. Preincubation of the apical surface of cultures with antisera directed against hACE2 reduced viral titers by 2 logs while antisera against DC-SIGN/DC-SIGNR did not reduce viral replication levels suggesting that hACE2 is the primary receptor for entry of SARS-CoV into the ciliated cells of HAE cultures. To assess infectivity in ciliated airway cultures derived from susceptible animal species we generated a recombinant SARS-CoV by deletion of open reading frame 7a/7b (ORF 7a/b) and insertion of the green fluorescent protein (GFP) resulting in SARS-CoV GFP. SARS-CoV GFP replicated to similar titers as wild type viruses in Vero E6, MA104, and CaCo2 cells. In addition, SARS-CoV replication in airway epithelial cultures generated from Golden Syrian hamster tracheas reached similar titers to the human cultures by 72 hours post infection. Efficient SARS-CoV infection of ciliated cell-types in HAE provides a useful in vitro model of human lung origin to study characteristics of SARS-CoV replication and pathogenesis. PMID:17451829

  1. Mannosylated Mucin-Type Immunoglobulin Fusion Proteins Enhance Antigen-Specific Antibody and T Lymphocyte Responses

    PubMed Central

    Johansson, Tomas; Nilsson, Anki; Chatzissavidou, Nathalie; Sjöblom, Magnus; Rova, Ulrika; Holgersson, Jan

    2012-01-01

    Targeting antigens to antigen-presenting cells (APC) improve their immunogenicity and capacity to induce Th1 responses and cytotoxic T lymphocytes (CTL). We have generated a mucin-type immunoglobulin fusion protein (PSGL-1/mIgG2b), which upon expression in the yeast Pichia pastoris became multivalently substituted with O-linked oligomannose structures and bound the macrophage mannose receptor (MMR) and dendritic cell-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN) with high affinity in vitro. Here, its effects on the humoral and cellular anti-ovalbumin (OVA) responses in C57BL/6 mice are presented. OVA antibody class and subclass responses were determined by ELISA, the generation of anti-OVA CTLs was assessed in 51Cr release assays using in vitro-stimulated immune spleen cells from the different groups of mice as effector cells and OVA peptide-fed RMA-S cells as targets, and evaluation of the type of Th cell response was done by IFN-γ, IL-2, IL-4 and IL-5 ELISpot assays. Immunizations with the OVA − mannosylated PSGL-1/mIgG2b conjugate, especially when combined with the AbISCO®-100 adjuvant, lead to faster, stronger and broader (with regard to IgG subclass) OVA IgG responses, a stronger OVA-specific CTL response and stronger Th1 and Th2 responses than if OVA was used alone or together with AbISCO®-100. Also non-covalent mixing of mannosylated PSGL-1/mIgG2b, OVA and AbISCO®-100 lead to relatively stronger humoral and cellular responses. The O-glycan oligomannoses were necessary because PSGL-1/mIgG2b with mono- and disialyl core 1 structures did not have this effect. Mannosylated mucin-type fusion proteins can be used as versatile APC-targeting molecules for vaccines and as such enhance both humoral and cellular immune responses. PMID:23071675

  2. Brugia malayi Antigen (BmA) Inhibits HIV-1 Trans-Infection but Neither BmA nor ES-62 Alter HIV-1 Infectivity of DC Induced CD4+ Th-Cells.

    PubMed

    Mouser, Emily E I M; Pollakis, Georgios; Yazdanbakhsh, Maria; Harnett, William; de Jong, Esther C; Paxton, William A

    2016-01-01

    One of the hallmarks of HIV-1 disease is the association of heightened CD4+ T-cell activation with HIV-1 replication. Parasitic helminths including filarial nematodes have evolved numerous and complex mechanisms to skew, dampen and evade human immune responses suggesting that HIV-1 infection may be modulated in co-infected individuals. Here we studied the effects of two filarial nematode products, adult worm antigen from Brugia malayi (BmA) and excretory-secretory product 62 (ES-62) from Acanthocheilonema viteae on HIV-1 infection in vitro. Neither BmA nor ES-62 influenced HIV-1 replication in CD4+ enriched T-cells, with either a CCR5- or CXCR4-using virus. BmA, but not ES-62, had the capacity to bind the C-type lectin dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) thereby inhibiting HIV-1 trans-infection of CD4+ enriched T-cells. As for their effect on DCs, neither BmA nor ES-62 could enhance or inhibit DC maturation as determined by CD83, CD86 and HLA-DR expression, or the production of IL-6, IL-10, IL-12 and TNF-α. As expected, due to the unaltered DC phenotype, no differences were found in CD4+ T helper (Th) cell phenotypes induced by DCs treated with either BmA or ES-62. Moreover, the HIV-1 susceptibility of the Th-cell populations induced by BmA or ES-62 exposed DCs was unaffected for both CCR5- and CXCR4-using HIV-1 viruses. In conclusion, although BmA has the potential capacity to interfere with HIV-1 transmission or initial viral dissemination through preventing the virus from interacting with DCs, no differences in the Th-cell polarizing capacity of DCs exposed to BmA or ES-62 were observed. Neither antigenic source demonstrated beneficial or detrimental effects on the HIV-1 susceptibility of CD4+ Th-cells induced by exposed DCs. PMID:26808476

  3. The effect of Dermatophagoides pteronyssinus group 7 allergen (Der p 7) on dendritic cells and its role in T cell polarization.

    PubMed

    Tsai, Jaw-Ji; Wang, Hsin-Chieh; Chiu, Chih-Liang; Liao, En-Chih

    2016-11-01

    The innate signaling pathway for Th2 immunity activated by inhaled allergens has not been well defined. Dendritic cells (DCs) can use their innate pattern-recognition Toll-like receptors and C-type lectin receptors to generate innate immunity and influence adaptive responses. The aim of this study was to investigate the glycoform of Dermatophagoides pteronyssinus group 7 allergen (Der p 7) and its functional interaction with dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN). Both bone marrow-derived dendritic cells (BMDCs) derived from mice and monocyte-derived DCs (MDDCs) derived from human peripheral blood mononuclear cells (PBMCs) were used to investigate the function of Der p 7. Dendritic cells derived from THP1 were used to investigate the glycol form of Der p 7. Der p 7 interacted with DC-SIGN as recognized by immunoprecipitation and glycoprotein staining, and its function was partially inhibited by deglycosylation. When BMDCs were cultured with Der p 7, the secretion of IL-6 and gene expressions of IL-6, OX40L and Jagged-1 were increased. IL4(+)/CD4(+) T cells could be induced by Der p 7, however IFN-γ(+)/CD4(+) T cells were down-regulated. The effects of Der p 7 on DCs were down-regulated in the presence of DC-SIGN or TLR4 antibodies and deglycosylation. rDer p 7 enhanced the DC differentiation of CD80 and CD86. The effects of Der p 7 pulsed-MDDCs on IL4(+)/CD4(+) and IFN-γ(+)/CD4(+) T-cell differentiation of human PBMCs were significantly increased after Der p 7 stimulation and decreased by DC-SIGN antibody inhibition. In conclusion, the Der p 7 is a glycoprotein and its function was partially through glycan binding. BMDCs could be activated by Der p 7 through TLR4 and DC-SIGN, and followed by the expression of OX40 ligand (OX40L) and Jagged-1, the expressions of IL4(+)/CD4(+) cells were enhanced. These findings identify a previously unrecognized function of Der p 7 and establish a link between innate TLR4/C

  4. The effect of Dermatophagoides pteronyssinus group 7 allergen (Der p 7) on dendritic cells and its role in T cell polarization.

    PubMed

    Tsai, Jaw-Ji; Wang, Hsin-Chieh; Chiu, Chih-Liang; Liao, En-Chih

    2016-11-01

    The innate signaling pathway for Th2 immunity activated by inhaled allergens has not been well defined. Dendritic cells (DCs) can use their innate pattern-recognition Toll-like receptors and C-type lectin receptors to generate innate immunity and influence adaptive responses. The aim of this study was to investigate the glycoform of Dermatophagoides pteronyssinus group 7 allergen (Der p 7) and its functional interaction with dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN). Both bone marrow-derived dendritic cells (BMDCs) derived from mice and monocyte-derived DCs (MDDCs) derived from human peripheral blood mononuclear cells (PBMCs) were used to investigate the function of Der p 7. Dendritic cells derived from THP1 were used to investigate the glycol form of Der p 7. Der p 7 interacted with DC-SIGN as recognized by immunoprecipitation and glycoprotein staining, and its function was partially inhibited by deglycosylation. When BMDCs were cultured with Der p 7, the secretion of IL-6 and gene expressions of IL-6, OX40L and Jagged-1 were increased. IL4(+)/CD4(+) T cells could be induced by Der p 7, however IFN-γ(+)/CD4(+) T cells were down-regulated. The effects of Der p 7 on DCs were down-regulated in the presence of DC-SIGN or TLR4 antibodies and deglycosylation. rDer p 7 enhanced the DC differentiation of CD80 and CD86. The effects of Der p 7 pulsed-MDDCs on IL4(+)/CD4(+) and IFN-γ(+)/CD4(+) T-cell differentiation of human PBMCs were significantly increased after Der p 7 stimulation and decreased by DC-SIGN antibody inhibition. In conclusion, the Der p 7 is a glycoprotein and its function was partially through glycan binding. BMDCs could be activated by Der p 7 through TLR4 and DC-SIGN, and followed by the expression of OX40 ligand (OX40L) and Jagged-1, the expressions of IL4(+)/CD4(+) cells were enhanced. These findings identify a previously unrecognized function of Der p 7 and establish a link between innate TLR4/C

  5. Brugia malayi Antigen (BmA) Inhibits HIV-1 Trans-Infection but Neither BmA nor ES-62 Alter HIV-1 Infectivity of DC Induced CD4+ Th-Cells

    PubMed Central

    Mouser, Emily E. I. M.; Pollakis, Georgios; Yazdanbakhsh, Maria; Harnett, William

    2016-01-01

    One of the hallmarks of HIV-1 disease is the association of heightened CD4+ T-cell activation with HIV-1 replication. Parasitic helminths including filarial nematodes have evolved numerous and complex mechanisms to skew, dampen and evade human immune responses suggesting that HIV-1 infection may be modulated in co-infected individuals. Here we studied the effects of two filarial nematode products, adult worm antigen from Brugia malayi (BmA) and excretory-secretory product 62 (ES-62) from Acanthocheilonema viteae on HIV-1 infection in vitro. Neither BmA nor ES-62 influenced HIV-1 replication in CD4+ enriched T-cells, with either a CCR5- or CXCR4-using virus. BmA, but not ES-62, had the capacity to bind the C-type lectin dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) thereby inhibiting HIV-1 trans-infection of CD4+ enriched T-cells. As for their effect on DCs, neither BmA nor ES-62 could enhance or inhibit DC maturation as determined by CD83, CD86 and HLA-DR expression, or the production of IL-6, IL-10, IL-12 and TNF-α. As expected, due to the unaltered DC phenotype, no differences were found in CD4+ T helper (Th) cell phenotypes induced by DCs treated with either BmA or ES-62. Moreover, the HIV-1 susceptibility of the Th-cell populations induced by BmA or ES-62 exposed DCs was unaffected for both CCR5- and CXCR4-using HIV-1 viruses. In conclusion, although BmA has the potential capacity to interfere with HIV-1 transmission or initial viral dissemination through preventing the virus from interacting with DCs, no differences in the Th-cell polarizing capacity of DCs exposed to BmA or ES-62 were observed. Neither antigenic source demonstrated beneficial or detrimental effects on the HIV-1 susceptibility of CD4+ Th-cells induced by exposed DCs. PMID:26808476

  6. Sialylated intravenous immunoglobulin suppress anti-ganglioside antibody mediated nerve injury.

    PubMed

    Zhang, Gang; Massaad, Cynthia A; Gao, Tong; Pillai, Laila; Bogdanova, Nataliia; Ghauri, Sameera; Sheikh, Kazim A

    2016-08-01

    The precise mechanisms underlying the efficacy of intravenous immunoglobulin (IVIg) in autoimmune neurological disorders including Guillain-Barré syndrome (GBS) are not known. Anti-ganglioside antibodies have been reported to be pathogenic in some variants of GBS, and we have developed passive transfer animal models to study anti-ganglioside antibody mediated-endoneurial inflammation and associated neuropathological effects and to evaluate the efficacy of new therapeutic approaches. Some studies indicate that IVIg's anti-inflammatory activity resides in a minor sialylated IVIg (sIVIg) fractions and is dependent on an innate Th2 response via binding to a specific ICAM3-grabbing nonintegrin related 1 receptor (SIGN-R1). Therefore the efficacy of IVIg, IVIg fractions with various IgG Fc sialylation status, and the involvement of Th2 pathway were examined in one of our animal model of antibody-mediated inhibition of axonal regeneration. We demonstrate that both IVIg and sIVIg ameliorated anti-glycan antibody mediated-pathological effect, whereas, the unsialylated fractions of IVIg were not beneficial in our model. Tenfold lower doses of sIVIg compared to whole IVIg provided equivalent efficacy in our studies. Moreover, we found that whole IVIg and sIVIg significantly upregulates the gene expression of IL-33, which itself can provide protection from antibody-mediated nerve injury in our model. Our results support that the SIGN-R1-Th2 pathway is involved in the anti-inflammatory effects of IVIg on endoneurium in our model and elements of this pathway including IL-33 can provide novel therapeutics in inflammatory neuropathies. PMID:27208700