Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The carboxy termini of the three glycoproteins (prM, E, and NS1) specified by dengue virus type 2 (DEN-2) were determined. The glycoproteins were radiolabeled with selected amino acids chosen following analysis of the deduced amino acid sequence of the polyprotein and then digested with carboxypeptidase A. The pattern of release of radioactive amino acids enabled definition of the carboxy termini. In addition, the amino terminus of NS2A was determined by Edman degradation of the radiolabeled protein. The results showed that no amino acids were lost at the carboxy termini of prM, E, and NS1 during their cleavage from the DEN-2 polyprotein. For each glycoprotein, the carboxy terminal amino acid immediately preceded the amino terminal acid of the following polypeptide.
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PMID:Definition of the carboxy termini of the three glycoproteins specified by dengue virus type 2. 274 48

Dengue type 2 virus (DEN 2) could replicate only to a limited extent in a murine mastocytoma cell line, P815. The viral multiplication was enhanced 10- to 100-fold by mouse anti-DEN 2 antiserum or anti-DEN 2 type-specific monoclonal antibody diluted beyond their neutralizing titers. Cells incubated with virus-antibody mixtures changed morphologically, developing a mature mast cell-like appearance, 4-5 days after infection. The indirect fluorescent antibody technique showed that the enhancement of infection was caused by an increase in the number of DEN 2-infected cells. This is the first report that cells of mast cell lineage support dengue virus multiplication, and that virus production is enhanced in the presence of anti-dengue antibodies.
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PMID:Antibody-mediated enhancement of infection by dengue virus of the P815 murine mastocytoma cell line. 310 62

We report here the first demonstration of dengue virus infection and vasoactive cytokine response of a cell of the mast cell/basophil lineage. Infection of KU812 cells was dependent on dengue-specific antibody and gave rise to infectious virions. This antibody-enhanced dengue virus infection triggered a four- to fivefold increase in the release of interleukin-1beta (IL-1beta) and a modest increase for IL-6 but not for an alternate cytokine, granulocyte-macrophage colony-stimulating factor. The results suggest a potential role for mast cells/basophils in the pathogenesis of dengue virus-induced disease.
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PMID:Release of vasoactive cytokines by antibody-enhanced dengue virus infection of a human mast cell/basophil line. 1088 55

Severe dengue virus infections usually occur in individuals who have preexisting anti-dengue virus antibodies. Mast cells are known to play an important role in host defense against several pathogens, but their role in viral infection has not yet been elucidated. The effects of dengue virus infection on the production of chemokines by human mast cells were examined. Elevated levels of secreted RANTES, MIP-1alpha, and MIP-1beta, but not IL-8 or ENA-78, were observed following infection of KU812 or HMC-1 human mast cell-basophil lines. In some cases a >200-fold increase in RANTES production was observed. Cord blood-derived cultured human mast cells treated with dengue virus in the presence of subneutralizing concentrations of dengue virus-specific antibody also demonstrated significantly (P < 0.05) increased RANTES production, under conditions which did not induce significant degranulation. Chemokine responses were not observed when mast cells were treated with UV-inactivated dengue virus in the presence or absence of human dengue virus-specific antibody. Neither antibody-enhanced dengue virus infection of the highly permissive U937 monocytic cell line nor adenovirus infection of mast cells induced a RANTES, MIP-1alpha, or MIP-1beta response, demonstrating a selective mast cell response to dengue virus. These results suggest a role for mast cells in the initiation of chemokine-dependent host responses to dengue virus infection.
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PMID:Dengue virus selectively induces human mast cell chemokine production. 1213 44

Mast cells have been most widely studied in the context of allergic disease but also play a critical role in host defence against bacterial infection, most elegantly demonstrated in studies using mast cell deficient w/wv mice. There is less data available concerning the role of mast cells in defence against viral pathogens, however, mast cells have been demonstrated to be a potential reservoir of infection for several pathogens, such as HIV-1 and dengue, and capable of producing mediators following challenge with a number of viral products. Traditional mast cell mediators such as histamine, protease enzymes and leukotrienes are important for effective host responses. The cytokines and chemokines produced by mast cells in response to pathogens are known to profoundly alter the nature of the innate immune response and its effectiveness in eliminating infection. Cytokine and chemokine production by mast cells is closely regulated and may occur independently of classical mast cell degranulation. Depending upon the nature of the stimulus or type of infection, a unique profile of cytokines is induced. In this review, we will examine the role and regulation of mast cell cytokines and chemokines in the context of a number of bacterial and viral infections, emphasizing the multiple receptor mechanisms used to activate mast cells. This area of research is still in its early stages and much work remains to be done. However, understanding the unique properties of resident tissue mast cells and how their cytokine responses are regulated by pathogens or pathogen products, will provide important opportunities for the therapeutic manipulation of local immune responses.
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PMID:Mast cell cytokine and chemokine responses to bacterial and viral infection. 1257 Jun 71

The difficulty in studying dengue virus (DENV) infection in humans and in developing a virus vaccine is the absence of a suitable animal model which develops the full spectra of the Dengue haemorrhagic fever (DHF) and Dengue shock syndrome (DSS). Despite the fact that viruses have been found in various animal tissues, we isolated DENV from tissues of adult BALB/c mice, inoculated with DENV serotype 2 (DENV-2) obtained from human serum. Viruses were ultrastructurally identified and immunolocalized by immunofluorescence techniques in C6/36 mosquito cell cultures, inoculated with tissues (liver, lung, kidney and cerebellum) macerate supernatant from mice, 48 h post-infection (p.i.). These organs, collected at the same stage of infection, were examined histologically. The histopathological analysis revealed focal alterations in all tissues examined. Liver contained focal ballooned hepatocytes, but without modifying the average diameter of the majority of hepatocytes. Sinusoidal lumen was significantly diminished at this stage but portal and centrolobular veins became congested. Lungs exhibited hemorrhagic foci in the alveolar space, vascular congestion and focal alveolitis. Cerebellar tissue showed rare foci of neuronal compactation (Purkinje cells) and perivascular oedema. In kidneys it was observed an increase in glomerular volume with augmented endocapillary and mesangial cellularity, with reactivity to anti-IgM in all glomeruli of infected mice. In conclusion, DENV-2 was found in all tissues examined early in the evolution of infection. Presence of viruses in tissues has mainly led to hemodynamic alterations with generalized vascular congestion and increased permeability, and mast cell recruitment in lungs. The latter could participate in the vascular modifications in tissues.
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PMID:Histopathological aspects of Dengue-2 virus infected mice tissues and complementary virus isolation. 1555 98

Mosquitoes (Aedes aegypti) were genetically modified to exhibit impaired vector competence for dengue type 2 viruses (DENV-2). We exploited the natural antiviral RNA interference (RNAi) pathway in the mosquito midgut by constructing an effector gene that expresses an inverted-repeat (IR) RNA derived from the premembrane protein coding region of the DENV-2 RNA genome. The A. aegypti carboxypeptidase A promoter was used to express the IR RNA in midgut epithelial cells after ingestion of a bloodmeal. The promoter and effector gene were inserted into the genome of a white-eye Puerto Rico Rexville D (Higgs' white eye) strain by using the nonautonomous mariner MosI transformation system. A transgenic family, Carb77, expressed IR RNA in the midgut after a bloodmeal. Carb77 mosquitoes ingesting an artificial bloodmeal containing DENV-2 exhibited marked reduction of viral envelope antigen in midguts and salivary glands after infection. DENV-2 titration of individual mosquitoes showed that most Carb77 mosquitoes poorly supported virus replication. Transmission in vitro of virus from the Carb77 line was significantly diminished when compared to control mosquitoes. The presence of DENV-2-derived siRNAs in RNA extracts from midguts of Carb77 and the loss of the resistance phenotype when the RNAi pathway was interrupted proved that DENV-2 resistance was caused by a RNAi response. Engineering of transgenic A. aegypti that show a high level of resistance against DENV-2 provides a powerful tool for developing population replacement strategies to control transmission of dengue viruses.
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PMID:Engineering RNA interference-based resistance to dengue virus type 2 in genetically modified Aedes aegypti. 1653 8

Dengue virus is a major mosquito-borne human pathogen with four known serotypes. The presence of antidengue virus antibodies in the serum of individuals prior to dengue virus infection is believed to be an important risk factor for severe dengue virus disease as a result of the phenomenon of antibody-dependent enhancement operating on Fc receptor (FcR)-bearing cells. In addition to blood monocytes, mast cells are susceptible to antibody-enhanced dengue virus infection, producing a number of inflammatory mediators including IL-1, IL-6, and CCL5. Using the human mast cell-like lines KU812 and HMC-1 as well as primary cultures of human cord blood-derived mast cells (CBMC), we aimed to identify the participating FcRs in antibody-enhanced mast cell dengue virus infection, as FcRs represent a potential site for therapeutic intervention. CBMC expressed significant levels of FcgammaRI, FcgammaRII, and FcgammaRIII, and mast cell-like HMC-1 and KU812 cells expressed predominantly FcgammaRII. All four serotypes of dengue virus showed antibody-enhanced binding to KU812 cells. Specific FcgammaRII blockade with mAb IV.3 was found to significantly abrogate dengue virus binding to KU812 cells and CBMC in the presence of dengue-specific antibody. Dengue virus infection and the production of CCL5 by KU812 cells were also inhibited by FcgammaRII blockade.
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PMID:A dominant role for FcgammaRII in antibody-enhanced dengue virus infection of human mast cells and associated CCL5 release. 1694 Mar 32

Severe forms of dengue virus disease, known as dengue hemorrhagic fever and dengue shock syndrome, result from an aberrant immune response involving antibody-dependent enhancement of infection, thrombocytopenia, and a loss of vascular integrity, culminating in hemorrhage, shock, and in some cases, death. Several studies have indicated that dengue virus infection results in the induction of apoptosis of certain cells believed to be contributory players in dengue pathogenesis. However, none have specifically examined the role of antibody enhancement in the context of induction of apoptosis. Here, we show that antibody-enhanced dengue virus infection of the FcR-bearing mast cell/basophil KU812 cell line results in a massive induction of apoptosis. Confocal microscopy and flow cytometry indicate two distinct subpopulations consisting of productively infected cells and apoptotic-uninfected bystanders. Apoptosis was found to be caspase-dependent, involving global caspase activation and cleavage of poly-ADP-ribose polymerase (PARP) and D4-guanosine diphosphate dissociation inhibitor (D4-GDI). Additional FcR-bearing cells, including K562, U937, and human mast cell 1 (HMC-1), were analyzed for apoptosis induction following infection. Although all cells displayed high susceptibility to antibody-enhanced dengue virus infection, only cells of a mast cell phenotype (KU812 and HMC-1) were found to undergo apoptosis. Dengue-induced apoptosis of KU812 cells was shown to require antibody-enhanced dengue virus infection by blockade of FcgammaRII. Transfection of KU812 cells with L-SIGN/DC-SIGNR was able to overcome the requirement for antibody enhancement with regard to dengue virus infection and apoptosis.
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PMID:Dramatic caspase-dependent apoptosis in antibody-enhanced dengue virus infection of human mast cells. 1880 35

Vascular perturbation is a hallmark of severe forms of dengue disease. We show here that antibody-enhanced dengue virus infection of primary human cord blood-derived mast cells (CBMCs) and the human mast cell-like line HMC-1 results in the release of factor(s) which activate human endothelial cells, as evidenced by increased expression of the adhesion molecules ICAM-1 and VCAM-1. Endothelial cell activation was prevented by pretreatment of mast cell-derived supernatants with a tumor necrosis factor (TNF)-specific blocking antibody, thus identifying TNF as the endothelial cell-activating factor. Our findings suggest that mast cells may represent an important source of TNF, promoting vascular endothelial perturbation following antibody-enhanced dengue virus infection.
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PMID:Dengue virus infection of mast cells triggers endothelial cell activation. 2106 56


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