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Query: UMLS:C0038362 (
stomatitis
)
8,852
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Upon stimulation with alpha/beta interferon, rat cells synthesize three Mx proteins. Sequence analysis of corresponding cDNAs reveals that these three proteins are derived from three distinct genes. One of the rat cDNAs is termed Mx1 because it is most closely related to the mouse Mx1 cDNA and because it codes for a
nuclear protein
that, like the mouse Mx1 protein, inhibits influenza virus growth. However, this protein differs from mouse Mx1 protein, in that it also inhibits vesicular
stomatitis
virus (VSV), a rhabdovirus. A second rat cDNA is more closely related to the mouse Mx2 cDNA and directs the synthesis of a cytoplasmic protein that inhibits VSV but not influenza virus. The third rat cDNA codes for a cytoplasmic protein that differs from the second one in only eight positions and has no detectable activity against either virus. These results indicate that rat Mx proteins have antiviral specificities not anticipated from the analysis of the murine Mx1 protein.
...
PMID:Activity of rat Mx proteins against a rhabdovirus. 217 90
A C164Y somatic mutation in the H-2Kb class I molecule causes a disruption of the alpha 2 domain disulfide bond and results in a loss of H-2Kb cell surface expression by the 69.9.15 cell line. In vitro culture of the somatic cell variant at 30 degrees C induced weak, but reproducible, expression of the H-2Kb mutant molecule on the cell surface, which suggests that a temperature-sensitive mutation was contributing to the H-2Kb null phenotype. Based on the inherent structural instability of the mutant H-2Kb molecules synthesized by 69.9.15 cells, we sought to determine the ability of high affinity peptide-ligand to counteract the null expression of H-2Kb. Treatment of 69.9.15 cells was performed with acid-eluted cell-derived peptides, as well as synthetic H-2Kb-restricted peptides, ovalbumin (OVA) p257-264 (YSIINFEKL), and vesicular
stomatitis
virus-
nuclear protein
p52-59 (RGYVYQGL). Whereas the endogenous and vesicular
stomatitis
virus peptides were ineffective at inducing H-2Kb expression at either 37 degrees C or 30 degrees C, treatment with the OVA peptide at 30 degrees C gave rise to dose-dependent enhancement in H-2Kb expression, an effect that was independent of exogenous sources of bovine beta 2-microglobulin at the time of peptide treatment. By comparison, expression of H-2Kb remained unaltered when cells were treated with the OVA peptide at 37 degrees C, consistent with the temperature-sensitive expression of the mutant molecules. Decay of H-2Kb from the cell surface was similar for both 69.9.15 and RMA-S cells, an indication that binding of OVA p257-264 provided the same level of stability for class I molecules with either a cis-(69.9.15) or trans-acting (RMA-S) defect in heavy chain transport. These data provide novel evidence that transport-defective MHC class I molecules, similar in nature to those encoded by class I genes isolated from human genomic libraries, i.e., the 12.4 pseudogene with a polymorphism at amino acid position 164 (C-->F), are subject to high affinity peptide-induced stabilization which reverses the class I null phenotype.
...
PMID:Failure in expression of structurally altered (CYS164-->TYR) H-2Kb molecules is mitigated with high affinity peptide-ligand. 776 72
The 3' ends of the genome and antigenome RNA of vesicular
stomatitis
virus (VSV) serve as the promoter sites for the RNA-dependent RNA polymerase in the initiation of transcription and replication, respectively. The leader RNA, the first transcript synthesized during the RNA synthetic step, contains sequences to initiate encapsidation with the nucleocapsid protein, which is a prerequisite for replication. It also plays a role in the inhibition of cellular RNA synthesis. To search for a specific cellular factor(s) which may interact with the leader RNA sequences and regulate these processes, we used a gel mobility shift assay to identify such a protein(s). By using nuclear extract, it was found that in addition to the previously reported La protein, a 120-kDa
nuclear protein
specifically interacts with the leader RNA. Biochemical and immunological studies identified the 120-kDa protein as heterogeneous nuclear ribonucleoprotein particle U (hnRNP U), which is involved in pre-mRNA processing. We also demonstrate that hnRNP U is associated with the leader RNA in the nuclei of VSV-infected cells and also packaged within the purified virions. By double immunofluorescence labeling and confocal microscopy, hnRNP U appears to colocalize with the virus in the cytoplasm of infected cells. These results strongly suggest that hnRNP U plays an important role in the life cycle of VSV.
...
PMID:Specific interaction of heterogeneous nuclear ribonucleoprotein particle U with the leader RNA sequence of vesicular stomatitis virus. 976 91
Human herpesvirus 8 (HHV-8; Kaposi's sarcoma herpesvirus) encodes four open reading frames with homology to cellular proteins of interferon regulatory factor (IRF) family. Three of them, viral IRF-1 (vIRF-1), vIRF-2, and vIRF-3, have been cloned and found, when overexpressed, to down-regulate the transcriptional activity of interferon type I gene promoters in infected cells by interfering with the transactivating activity of cellular IRFs. In this study, we have further characterized vIRF-2 and shown that it is a
nuclear protein
which is constitutively expressed in HHV-8-positive pleural effusion lymphoma cell lines. Nuclear localization of vIRF-2 was confirmed by in situ detection of ectopically expressed enhanced green fluorescent protein/vIRF-2 fusion protein. We found that the expression of vIRF-2 in HEK293 cells inhibited the antiviral effect of interferon and rescued translation of vesicular
stomatitis
virus mRNA from interferon-induced translational block. To provide insight into the mechanism of this effect we have demonstrated that vIRF-2 physically interacts with PKR consequently inhibiting autophosphorylation of double-stranded RNA-activated protein kinase (PKR) and blocking phosphorylation of PKR substrates histone 2A and eukaryotic translation initiation factor 2alpha. These results suggest that the latently expressed vIRF-2 has a role in viral mimicry which targets the activity of interferon-induced PKR kinase. By inhibiting the kinase activity of PKR and consequent down-modulation of protein synthesis, HHV-8 has evolved a mechanism by which it can overcome the interferon-mediated antiviral effect. Thus, the anti-interferon functions of vIRF-2 may contribute to the establishment of a chronic or latent infection.
...
PMID:Latently expressed human herpesvirus 8-encoded interferon regulatory factor 2 inhibits double-stranded RNA-activated protein kinase. 1116 Jul 38
The balance between astrocyte and microglia neuroprotection and neurotoxicity defines the tempo of neuronal dysfunction during HIV-1-associated dementia (HAD). Astrocytes maintain brain homeostasis and respond actively to brain damage by providing functional and nutritive neuronal support. In HAD, low-level, continuous infection of astrocytes occurs, but the functional consequences of this infection are poorly understood. To this end, human fetal astrocytes (HFA) and monocyte-derived macrophages (MDM) were infected with HIV-1DJV and HIV-1NL4-3 (neurotropic and lymphotropic strains respectively) and a pseudotyped Vesicular
Stomatitis
Virus (VSV/HIV-1NL4-3) prior to intracranial injection into the basal ganglia of severe combined immunodeficient mice. Neuropathological and immunohistochemical comparisons for inflammatory and neurotoxic activities were performed amongst the infected cell types at 7 or 14 days. HIV-1-infected MDM induced significant increases in Mac-1, glial fibrillary acidic protein, ionized calcium-binding adapter molecule 1, and proinflammatory cytokine RNA and/or protein expression when compared with HSV/HIV-1- and HIV-1-infected HFA and sham-operated mice. Levels of neuron-specific
nuclear protein
, microtubule-associated protein 2, and neurofilament antigens were reduced significantly in the brain regions injected with human MDM infected with HIV-1DJV or VSV/HIV-1. We conclude that HIV-1 infection of astrocytes leads to limited neurodegeneration, underscoring the early and active role of macrophage-driven neurotoxicity in disease.
...
PMID:Neuropathologic and neuroinflammatory activities of HIV-1-infected human astrocytes in murine brain. 1670 72
Intranasal application of vesicular
stomatitis
virus (VSV) causes acute infection of the central nervous system (CNS). However, VSV encephalitis is not invariably fatal, suggesting that the CNS may contain a professional antigen-presenting cell (APC) capable of inducing or propagating a protective antiviral immune response. To examine this possibility, we first characterized the cellular elements that infiltrate the brain as well as the activation status of resident microglia in the brains of normal and transgenic mice acutely ablated of peripheral dendritic cells (DCs) in vivo. VSV encephalitis was characterized by a pronounced infiltrate of myeloid cells (CD45(high)CD11b(+)) and CD8(+) T cells containing a subset that was specific for the immunodominant VSV
nuclear protein
epitope. This T cell response correlated temporally with a rapid and sustained upregulation of MHC class I expression on microglia, whereas class II expression was markedly delayed. Ablation of peripheral DCs profoundly inhibited the inflammatory response as well as infiltration of virus-specific CD8(+) T cells. Unexpectedly, the VSV-induced interferon-gamma (IFN-gamma) response in the CNS remained intact in DC-deficient mice. Thus, both the inflammatory and certain components of the adaptive primary antiviral immune response in the CNS are dependent on peripheral DCs in vivo.
...
PMID:Peripheral dendritic cells are essential for both the innate and adaptive antiviral immune responses in the central nervous system. 1926 38
Adenosine deaminases acting on RNA (ADARs) catalyze the C-6 deamination of adenosine (A) to produce inosine (I), which behaves as guanine (G), thereby altering base pairing in RNAs with double-stranded character. Two genes, adar1 and adar2, are known to encode enzymatically active ADARs in mammalian cells. Furthermore, two size forms of ADAR1 are expressed by alternative promoter usage, a short (p110) nuclear form that is constitutively made and a long (p150) form that is interferon inducible and present in both the cytoplasm and nucleus. ADAR2 is also a constitutively expressed
nuclear protein
. Extensive A-to-G substitution has been described in mouse polyomavirus (PyV) RNA isolated late times after infection, suggesting modification by ADAR. To test the role of ADAR in PyV infection, we used genetically null mouse embryo fibroblast cells deficient in either ADAR1 or ADAR2. The single-cycle yields and growth kinetics of PyV were comparable between adar1(-/-) and adar2(-/-) genetic null fibroblast cells. While large T antigen was expressed to higher levels in adar1(-/-) cells than adar2(-/-) cells, less difference was seen in VP1 protein expression levels between the two knockout MEFs. However, virus-induced cell killing was greatly enhanced in PyV-infected adar1(-/-) cells compared to that of adar2(-/-) cells. Complementation with p110 protected cells from PyV-induced cytotoxicity. UV-irradiated PyV did not display any enhanced cytopathic effect in adar1(-/-) cells. Reovirus and vesicular
stomatitis
virus single-cycle yields were comparable between adar1(-/-) and adar2(-/-) cells, and neither reovirus nor VSV showed enhanced cytotoxicity in adar1(-/-)-infected cells. These results suggest that ADAR1 plays a virus-selective role in the host response to infection.
...
PMID:Host response to polyomavirus infection is modulated by RNA adenosine deaminase ADAR1 but not by ADAR2. 2163 55
Chronic ulcerative
stomatitis
is an immune-mediated mucocutaneous disorder characterized clinically by erosions or ulcers. Most cases are limited to the mouth. The histopathological features are non-specific or mimic those of oral lichen planus, and studies by immunofluorescent microscopy are essential for definitive diagnosis. The defining immunopathogenic mechanism is the binding of IgG to the
nuclear protein
deltaNp63alpha of keratinocytes in the basal and parabasal cell layers of the oral stratified epithelium. DeltaNp63alpha functions as a regulator of epithelial stem cell activity and as an antiapoptotic agent and regulates the expression of cell-to-cell and cell-to-basement membrane adhesion molecules. The autoimmune IgG-deltaNp63alpha interaction is thought to result in damage to the structural attachment of keratinocytes to one another and to the epithelial basement membrane zone and in dysregulation of the cell cycle and apoptosis of basal keratinocytes with the development of erosions or ulcers. The aims of treatment are to suppress the pathogenic immunoinflammatory responses, to prevent local infection and to promote healing. The purpose of this article is to provide a succinct review of the diagnostic, clinical and etiopathogenic features of, and treatment guidelines for chronic ulcerative
stomatitis
, and to argue that this disease should be regarded as a variant of oral lichen planus, rather than as a distinct entity.
...
PMID:Is chronic ulcerative stomatitis a variant of lichen planus, or a distinct disease? 2818 59
The BAF-chromatin remodeling complex, with its mutually exclusive ATPases SMARCA2 and SMARCA4, is essential for the transcriptional activation of numerous genes, including a subset of interferon-stimulated genes (ISGs). Here, we show that C-terminally truncated forms of both SMARCA2 and SMARCA4 accumulate in cells infected with different RNA or DNA viruses. The levels of truncated SMARCA2 or SMARCA4 strongly correlate with the degree of cell damage and death observed after virus infection. The use of a pan-caspase inhibitor and genetically modified cell lines unable to undergo apoptosis revealed that the truncated forms result from the activity of caspases downstream of the activated intrinsic apoptotic pathway. C-terminally cleaved SMARCA2 and SMARCA4 lack potential nuclear localization signals as well as the bromo- and SnAC domain, with the latter two domains believed to be essential for chromatin association and remodeling. Consistent with this belief, C-terminally truncated SMARCA2 was partially relocated to the cytoplasm. However, the remaining
nuclear protein
was sufficient to induce ISG expression and inhibit the replication of vesicular
stomatitis
virus and influenza A virus. This suggests that virus-induced apoptosis does not occur at the expense of an intact interferon-mediated antiviral response pathway.
IMPORTANCE
Efficient induction of interferon-stimulated genes (ISGs) prior to infection is known to effectively convert a cell into an antiviral state, blocking viral replication. Additionally, cells can undergo caspase-mediated apoptosis to control viral infection. Here, we identify SMARCA2 and SMARCA4 to be essential for the efficient induction of ISGs but also to be targeted by cellular caspases downstream of the intrinsic apoptotic pathway. We find that C-terminally cleaved SMARCA2 and SMARCA4 accumulate at late stages of infection, when cell damage already had occurred. Cleavage of the C terminus removes domains important for nuclear localization and chromatin binding of SMARCA2 and SMARCA4. Consequently, the cleaved forms are unable to efficiently accumulate in the cell nucleus. Intriguingly, the remaining nuclear C-terminally truncated SMARCA2 still induced ISG expression, although to lower levels. These data suggest that in virus-infected cells caspase-mediated cell death does not completely inactivate the SMARCA2- and SMARCA4-dependent interferon signaling pathway.
...
PMID:Partial Inactivation of the Chromatin Remodelers SMARCA2 and SMARCA4 in Virus-Infected Cells by Caspase-Mediated Cleavage. 2984 89
In order to establish productive infection and dissemination, viruses usually evolve a number of strategies to hijack and/or subvert the host defense systems. However, host factors utilized by the virus to facilitate infection remain poorly characterized. In this work, we found that
Drosophila melanogaster
deficient in
budding uninhibited by benzimidazoles 1
(
bub1
), a highly conserved subunit of the kinetochore complex regulating chromosome congression (1), became resistant to
Drosophila C virus
(DCV) infection, evidenced in increased survival rates and reduced viral loads, compared to the wild-type control. Mechanistic analysis further showed that Bub1 also functioned in the cytoplasm and was essentially involved in clathrin-dependent endocytosis of DCV and other pathogens, thus limiting pathogen entry. DCV infection potentially had strengthened the interaction between Bub1 and the clathrin adaptor on the cell membrane. Furthermore, the conserved function of Bub1 was also verified in a mammalian cell line. Thus, our data demonstrated a previously unknown function of Bub1 that could be hijacked by pathogens to facilitate their infection and spread.
IMPORTANCE
In this work, we identify for the first time that the
nuclear protein
Bub1 (budding uninhibited by benzimidazoles 1), a highly conserved subunit of the kinetochore complex regulating chromosome congression, has a novel and important function on the cell membrane to facilitate the virus to enter host cells. Bub1 deficiency empowers the host to have the ability to resist viral infection in
Drosophila
and a human cell line. Bub1 is involved in the virus entry step through regulating endocytosis. The DCV capsid protein can recruit Bub1, and DCV infection can strengthen the interaction between Bub1 and a clathrin-dependent endocytosis component. The restricted entry of vesicular
stomatitis
virus (VSV) and
Listeria monocytogenes
in
bub1
-deficient flies and cell lines was also observed. Therefore, our data implicate a previously unknown function of Bub1 that can be hijacked by pathogens to facilitate their entry, and Bub1 may serve as a potential antiviral therapy target for limiting viral entry.
...
PMID:Bub1 Facilitates Virus Entry through Endocytosis in a Model of Drosophila Pathogenesis. 2997 67
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