Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0019158 (hepatitis)
30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intracerebral infection of mice with mouse hepatitis virus (MHV) results in an acute encephalomyelitis followed by a chronic demyelinating disease with clinical and histological similarities with the human demyelinating disease multiple sclerosis (MS). Following MHV infection, chemokines including CXC chemokine ligand (CXCL)10 (IFN inducible protein 10 kDa), CXCL9 (monokine induced by IFN-gamma), and CC chemokine ligand 5 (RANTES) are expressed during both acute and chronic stages of disease suggesting a role for these molecules in disease exacerbation. Previous studies have shown that during the acute phase of infection, T lymphocytes are recruited into the CNS by the chemokines CXCL10 and CXCL9. In the present study, MHV-infected mice with established demyelination were treated with antisera against these two chemokines, and disease severity was assessed. Treatment with anti-CXCL10 reduced CD4+ T lymphocyte and macrophage invasion, diminished expression of IFN-gamma and CC chemokine ligand 5, inhibited progression of demyelination, and increased remyelination. Anti-CXCL10 treatment also resulted in an impediment of clinical disease progression that was characterized by a dramatic improvement in neurological function. Treatment with antisera against CXCL9 was without effect, demonstrating a critical role for CXCL10 in inflammatory demyelination in this model. These findings document a novel therapeutic strategy using Ab-mediated neutralization of a key chemokine as a possible treatment for chronic human inflammatory demyelinating diseases such as MS.
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PMID:Neutralization of the chemokine CXCL10 reduces inflammatory cell invasion and demyelination and improves neurological function in a viral model of multiple sclerosis. 1156 31

An effective host response against viral infection of the central nervous system (CNS) is the principal factor dictating the outcome of infection. It is the responsibility of the immune response to contain and control viral replication. Paradoxically, it is the immune response that may also contribute to the development of neuropathology. We have used mouse hepatitis virus (MHV), apositive-strand RNA virus, infection of the CNS to understand the dynamic interaction between viral replication, protection, and pathology with an emphasis on understanding how chemokines participate in these interrelated processes. Herein, we demonstrate the complexity of the chemokine response to MHV infection of the CNS and the delicate balance that exists between host defense and development of disease.
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PMID:Chemokine expression and viral infection of the central nervous system: regulation of host defense and neuropathology. 1159 50

IFN-gamma-inducible protein 10 (IP-10, CXCL10), a chemokine secreted from cells stimulated with type I and II IFNs and LPS, is a chemoattractant for activated T cells. Expression of IP-10 is seen in many Th1-type inflammatory diseases, where it is thought to play an important role in recruiting activated T cells into sites of tissue inflammation. To determine the in vivo function of IP-10, we constructed an IP-10-deficient mouse (IP-10(-/-)) by targeted gene disruption. Immunological analysis revealed that IP-10(-/-) mice had impaired T cell responses. T cell proliferation to allogeneic and antigenic stimulation and IFN-gamma secretion in response to antigenic challenge were impaired in IP-10(-/-) mice. In addition, IP-10(-/-) mice exhibited an impaired contact hypersensitivity response, characterized by decreased ear swelling and reduced inflammatory cell infiltrates. T cells recovered from draining lymph nodes also had a decreased proliferative response to Ag restimulation. Furthermore, IP-10(-/-) mice infected with a neurotropic mouse hepatitis virus had an impaired ability to control viral replication in the brain. This was associated with decreased recruitment of CD4(+) and CD8(+) lymphocytes into the brain, reduced levels of IFN-gamma and the IFN-gamma-induced chemokines monokine induced by IFN-gamma (Mig, CXCL9) and IFN-inducible T cell alpha chemoattractant (I-TAC, CXCL11) in the brain, decreased numbers of virus-specific IFN-gamma-secreting CD8(+) cells in the spleen, and reduced levels of demyelination in the CNS. Taken together, our data suggest a role for IP-10 in both effector T cell generation and trafficking in vivo.
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PMID:IFN-gamma-inducible protein 10 (IP-10; CXCL10)-deficient mice reveal a role for IP-10 in effector T cell generation and trafficking. 1190 72

Chemokines are involved in the pathogenesis of alcoholic hepatitis and are considered to contribute to the migration of leukocytes into the liver during chronic ethanol intoxication. This work tests the hypothesis that chronic ethanol consumption selectively enhances chemokine release by Kupffer cells and hepatic sinusoidal endothelial cells and migration of inflammatory cells into the liver. Furthermore, enhanced hepatic chemokine secretion may induce an autocrine effect on the ability of Kupffer cells and endothelial cells to chemotax and ingest microbial particles. Male Wistar rats were fed with ethanol in agar block and water for 32 weeks, and were allowed free access to solid food. Results show that after 32 weeks of feeding, leukocyte infiltration and steatosis were observed in the livers of ethanol-fed rats. The majority of the infiltrated cells were CD8+ cells. Serum ALT, endotoxin, MIP-1alpha, MCP-1 and RANTES, (but not CINC and MIP-2) were also increased in the ethanol-fed rats than in the pair-fed group. Isolated Kupffer cells from ethanol-fed rats were primed for enhanced MIP-1alpha, MCP-1, and RANTES production in vitro, while the endothelial cells were primed for enhanced MIP-1alpha release only. Chronic alcohol intoxication was also associated with increased basal H2O2 formation, enhanced nuclear translocation and binding of NF-kappaB, AP-1 and MNP-1 in Kupffer Cells. Chronic ethanol feeding significantly enhanced MNP-1 binding, but not those of NF-kappaB and AP-1 in endothelial cells. Concomitantly, chemokine-induced chemotaxis, E.coli phagocytosis and f-met-leu-phe-induced superoxide anion production by Kupffer cells were downregulated in the ethanol-fed group. Taken together these data demonstrate that prolonged alcohol consumption may compromise the host to hepatitis as a result of increased chemokine production and at the same time may suppress the innate immune function of hepatic non-parenchymal cells.
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PMID:Chronic alcohol intoxication primes Kupffer cells and endothelial cells for enhanced CC-chemokine production and concomitantly suppresses phagocytosis and chemotaxis. 1204 6

Infection of the central nervous system (CNS) of susceptible mice with mouse hepatitis virus (MHV), a positive-strand RNA virus that is a member of the Coronaviridae family, reproducibly results in an acute encephalomyelitis followed by a demyelinating disease similar to the human demyelinating disease multiple sclerosis (MS). MHV infection triggers a robust cell-mediated response in which both CD4+ and CD8+ T cells are essential in controlling viral replication and spread. However, viral clearance is incomplete and viral RNA and protein can persist within white matter tracts, areas of viral persistence are often associated with demyelinating lesions, and recent studies have indicated an important role for both T cells and macrophages in contributing to myelin destruction. The molecular mechanisms governing leukocyte trafficking and accumulation within the CNS of MHV-infected mice are just now being understood and recent studies indicate that chemokines and chemokine receptors have an important role in this process. This article will provide an overview on how these molecules regulate T cell and macrophage trafficking into the CNS of MHV-infected mice and illustrate the delicate balance that exists with regards to expression of chemokines and their receptors as it relates to both host defense and disease development.
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PMID:Mouse hepatitis virus infection of the central nervous system: chemokine-mediated regulation of host defense and disease. 1208 Oct 11

The relationship(s) between viral virulence and matrix metalloproteinase (MMP) expression in the central nervous system (CNS) of mice undergoing lethal and sublethal infections with neurotropic mouse hepatitis virus was investigated. Lethal infection induced increased levels of MMP-3 and MMP-12 mRNAs as well as that of tissue inhibitor of matrix metalloproteinases 1 (TIMP-1) compared to sublethal infection. Increased induction of MMP, TIMP, and chemokine expression correlated with increased virus replication but not with inflammatory cell infiltration. Infection of immunosuppressed mice suggested that expression of most MMP, TIMP, and chemokine mRNA was induced primarily in CNS-resident cells. By contrast, MMP-9 protein activity was associated with the infiltration of neutrophils into the CNS. These data indicate an association between the magnitude of inflammatory gene expression within the CNS and viral virulence.
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PMID:Matrix metalloproteinase expression correlates with virulence following neurotropic mouse hepatitis virus infection. 1209 50

Hepatitis C virus (HCV) infection induces an acute and chronic liver inflammation through an immune-mediated pathway that may lead to cirrhosis and liver failure. Indeed, HCV-related hepatitis is characterized by a dramatic lymphocyte infiltrate into the liver which is mainly composed by HCV non-specific cells. Several data indicated that interferon (IFN)-gamma secretion by intrahepatic lymphocytes (IHL) may drive non-specific cell homing to the liver, inducing interferon inducible protein-10 (IP-10) production. An interesting hallmark of these IHL is the recruitment of lymphocytes associated with mechanisms of innate immunity, such as natural killer (NK), natural killer T (NKT) and gamma delta T lymphocytes. CD81 triggering on NK cell surface by the HCV envelope glycoprotein E2 was recently shown to inhibit NK cell function in the liver of HCV-infected persons, resulting in a possible mechanism contributing to the lack of virus clearance and to the establishment of chronic infection. In contrast, intrahepatic NKT cells restricted to CD1d molecules expressed on the hepatocyte surface may contribute to a large extent to liver damage. Finally, an increased frequency of T cells expressing the gamma delta T cell receptor (TCR) was observed in HCV-infected liver and recent observations indicate that intrahepatic gamma delta T cell activation could be directly induced by the HCV/E2 particle through CD81 triggering. These cells are not HCV specific, are able to kill target cells including primary hepatocytes and their ability to produce T helper (Th)1 cytokines is associated with a higher degree of liver disease. Together, CD1d/NKT and/or E2/CD81 interactions may play a major role in the establishment of HCV immunopathogenesis. In the absence of virus clearance, the chemokine-driven recruitment of lymphocytes with an innate cytotoxic behavior in the liver of HCV-infected patients may boost itself, leading to necroinflammatory and fibrotic liver disease.
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PMID:Lymphocyte distribution and intrahepatic compartmentalization during HCV infection: a main role for MHC-unrestricted T cells. 1245 64

Viral infection of the liver causes accumulation of T cells in the infected organ, raising the question as to the signals that mediate this response. Employing an adenovirus induced hepatitis model in mice, we show that IP-10 and Mig are essential for T cell recruitment and that induction of the two chemokines occurs concomitant to production of IFNgamma. It is shown that while IFNgamma induces IP-10 and Mig in hepatocytes, for optimal chemokine induction, a co-stimulatory signal mediated by cross-linking of Fas on hepatocytes is required. Moreover, cross-linking of Fas by injection of anti-Fas antibody into mice triggers induction of IP-10 and Mig in the liver. The cells providing the two signals are shown to express NK1.1 and AsGM1; elimination of these cells leads to inhibition of IFNgamma and chemokine transcript induction. The conclusion is drawn that both NK cells and T cells provide the two signals for induction of IP-10 and Mig in the liver.
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PMID:IP-10 and Mig facilitate accumulation of T cells in the virus-infected liver. 1247 67

Chemokines induce the directional migration of targeted populations of leukocytes during periods of inflammation. Moreover, these molecules also regulate T-cell activation and differentiation following antigenic stimulation. In the present study, the contributions of the CC chemokine ligand 3 (CCL3) to the differentiation and migration of effector T cells in response to viral infection of the central nervous system (CNS) were analyzed. CCL3(-/-) mice infected with mouse hepatitis virus exhibited a significant reduction of virus-specific CD8(+) T cells within the CNS, correlating with delayed viral clearance. Decreased infiltration of CD8(+) T cells into infected CCL3(-/-) mice was associated with enhanced accumulation of primed CD8(+) T cells in cervical lymph nodes. Although virus-specific CD8(+) T cells from CCL3(-/-) mice were CD44(high), they remained CD62L(high) and CD25(low), retained CCR7 expression, and contained limited transcripts of the proinflammatory chemokine receptors CCR5 and CXCR3 compared with virus-specific CD8(+) T cells from CCL3(+/+) mice. Furthermore, the absence of CCL3 impaired the cytokine production and cytolytic activity of CD8(+) T cells. In addition, macrophage accumulation within the CNS was significantly decreased in infected CCL3(-/-) mice, correlating with reduced demyelination. These results suggest that CCL3 not only mediates macrophage chemotaxis but also significantly enhances differentiation of primed CD8(+) T cells into effector cells and their release into circulation, thus potentiating effective migration to the site of infection.
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PMID:CC chemokine ligand 3 (CCL3) regulates CD8(+)-T-cell effector function and migration following viral infection. 1263 60

T cell-mediated liver diseases are associated with elevated serum levels of C-C chemokine ligand 2 (CCL2)/monocyte chemoattractant protein-1 (MCP-1). However, the extent to which the actions of CCL2/MCP-1 contribute to the pathogenesis of T cell-mediated hepatitis remains incompletely understood. Con A-induced hepatitis is a liver-specific inflammation mediated by activated T cells and is driven by an up-regulation of the hepatic expression of TNF-alpha, IFN-gamma, and IL-4. The present study examined the role of CCL2/MCP-1 in the pathogenesis of T cell-mediated hepatitis induced by Con A administration in the mouse. We demonstrate a novel hepatoprotective role for CCL2/MCP-1 during Con A-induced hepatitis, because CCL2/MCP-1 neutralization strikingly enhanced hepatic injury, both biochemically and histologically, after Con A administration. Furthermore, CCL2/MCP-1 neutralization was associated with a significant reduction in the hepatic levels of TNF-alpha and IFN-gamma, but with a significant increase in hepatic IL-4 levels. Moreover, IL-4 production and CCR2 expression by Con A-stimulated CD3(+)NK1.1(+) T cells was significantly reduced by rMCP-1 treatment in vitro. In summary, we propose that CCL2/MCP-1 fulfills a novel anti-inflammatory role in T cell-mediated hepatitis by inhibiting CD3(+)NK1.1(+) T cell-derived IL-4 production through direct stimulation of its specific receptor CCR2. These findings may have direct clinical relevance to T cell-mediated hepatitis.
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PMID:C-C chemokine ligand 2/monocyte chemoattractant protein-1 directly inhibits NKT cell IL-4 production and is hepatoprotective in T cell-mediated hepatitis in the mouse. 1273 74


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