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)

We herein report on two Japanese siblings with autoimmune polyglandular syndrome type 1 (APS-1). The brother, who expressed a characteristic phenotype of APS-1, had developed severe mucocutaneous candidiasis in early infancy and thereafter developed hypoparathyroidism and Addison's disease, along with a severe deterioration of his immunologic function. In contrast, the 44-year-old sister, who showed a noncharacteristic phenotype of APS-1, developed insulin-dependent diabetes with high anti-glutamic acid decarboxylase antibody, mild nail candidiasis, and autoimmune hepatitis with intact immunoreactivity. She had three susceptible human leukocyte antigen (HLA) loci for type 1 autoimmune diabetes. The expression of T cell receptor (TCR)V beta 5.1 increased in both patients, while the brother showed a widely suppressed expression of many TCRV beta families. Both individuals possessed compound heterozygous novel autoimmune regulator (AIRE) gene mutations (L29P and IVS9-1G > C). The same AIRE gene mutations can thus be associated with characteristic and noncharacteristic phenotypes of APS-1, and HLA may possibly influence the phenotype of APS-1.
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PMID:Distinct clinical phenotype and immunoreactivity in Japanese siblings with autoimmune polyglandular syndrome type 1 (APS-1) associated with compound heterozygous novel AIRE gene mutations. 1217 2

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

Efficient expression of genes transferred by retroviral vectors is a prerequisite for gene therapy, especially when the biological effect depends on the amount of transgene product. High-level gene expression is desirable for several gene therapy approaches involving T lymphocytes. We evaluated standard retroviral vectors with cis-regulatory control elements of the Moloney murine leukemia virus (Mo-MLV) with or without the human T cell-specific CD2 enhancer. For comparison, vectors containing the long terminal repeat (LTR) of myeloproliferative sarcoma virus (MPSV) and an improved 5' untranslated region were used (MP71 vectors), with or without the woodchuck hepatitis virus posttranscriptional regulatory element (PRE). All vectors expressed the enhanced green fluorescent protein (GFP) to measure transgene expression. In mouse T cells MP71 vectors with and without the PRE yielded an up to 10-fold higher expression level compared with the Mo-MLV-based vectors currently used for gene transfer into T lymphocytes. A high multiplicity of infection (MOI) of standard Mo-MLV vectors could not reach expression levels obtained with a low MOI of MP71 vector. Ex vivo-transduced mouse T lymphocytes maintained the vector-dependent differences in level of transgene expression in Rag-1-deficient mice when adoptively transferred. In four human T cell lines and human primary T lymphocytes MP71 vectors yielded an up to 75-fold higher GFP expression level in comparison with the standard Mo-MLV vector. In contrast to mouse T cells, the integration of the PRE into MP71 vectors induced in human T cells a further significant increase in transgene expression level. Southern blot analysis of CEM T cells revealed that the superior performance of MP71 vectors was not due to a higher rate of viral integration. In summary, MP71 vectors are useful tools for stable, high-level gene expression in T lymphocytes, for example, in the expression of T cell receptor genes.
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PMID:Retroviral vectors for high-level transgene expression in T lymphocytes. 1290 67

IL-18 is a pleiotropic cytokine and is produced by various types of cells including activated macrophages, particularly Kupffer cells. IL-18 has potential to activate inflammatory responses through induction of IFN-gamma production in collaboration with IL-12. Somewhat paradoxically, IL-18 also has the capacity to induce allergic responses via induction of IL-4 production by T helper cells and to activate mast cells and basophils to release atopic effector molecules such as histamine. Indeed, IL-18 is involved in inflammatory tissue injuries, such as Crohn's disease and atherosclerosis, and also in hyper IgE and atopic dermatitis. IL-18 is particularly important for induction of experimental liver diseases. Endotoxin-induced liver injury or Fas ligand-induced hepatitis is caused by endogenous IL-18 in mice. Moreover, patients with liver diseases such as fulminant hepatitis, liver cirrhosis due to hepatitis virus infection and primary biliary cirrhosis show elevation of serum levels of IL-18, that correlates with the corresponding disease severity. Therefore, endogenous IL-18 plays a major role in induction of some types of liver injuries in mice and human. NKT cells that express both T cell receptor and NK cell marker are abundant in the liver of mice and human. Recent studies have revealed that NKT cells participate in some types of liver injuries, such as concanavalin A-induced T cell-mediated hepatitis and malaria hepatitis. In this review article, we focus on IL-18-involving liver damages and NKT-cell-mediated liver injuries.
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PMID:Cytokine-induced inflammatory liver injuries. 1452 86

Mouse hepatitis virus type 3 (MHV3), a coronavirus, is an excellent animal model for the study of immunological disorders related to acute and chronic hepatitis. In this study, we have verified if the fulminant hepatitis induced by MHV3 could be related to an impairment of innate immunity. Groups of three C57BL/6 mice were infected with the pathogenic L2-MHV3 or attenuated YAC-MHV3 viruses, and the natural killer (NK) cell populations from liver, spleen and bone marrow were analysed. The percentage of intrahepatic NK1.1(+)T cell receptor (TCR)- cells did not increase while NK1.1(+)TCR(inter) cells decreased in both L2-MHV3- and YAC-MHV3-infected mice. Concurrently, splenic and myeloid NK1.1+ cells decreased in L2-MHV3-infected mice. However, the cytotoxic activity of NK cells increased in liver and decreased in bone marrow from pathogenic L2-MHV3-infected mice while no modification was detected in YAC-MHV3-infected mice. Flow cytometric analysis revealed that both normal and larger splenic or myeloid NK cells decreased more in pathogenic L2-MHV3-infected mice than in attenuated YAC-MHV3-infected mice. In vitro viral infections of interleukin (IL)-15-stimulated lymphoid cells from liver and bone marrow revealed that L2-MHV3 induced higher decreases in cell viability of NK1.1+ cells than the YAC-MHV3 variant. The NK cell decreases were due to the viral permissivity leading to cytopathic effects characterized by cell rounding, syncytia formation and apoptosis. Larger NK+ syncytia were observed in L2-MHV3-infected cells than in YAC-MHV3-infected cells. These results suggest that NK cell production is impaired by viral infection favouring fulminant hepatitis.
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PMID:Murine viral hepatitis involves NK cell depletion associated with virus-induced apoptosis. 1519 42

A rare case of reactive lymphoid hyperplasia (RLH) of the liver in a 75-year-old woman admitted to hospital for surgical treatment of gastric, caecal and colon carcinomas is described here. Two nodular lesions in the left and right lobes of the liver were clinically diagnosed as metastatic tumours by computed tomography of the abdomen. A demarcating grey-white mass of size 1.4 cm was observed in a partially resected liver specimen. On examining the lesion microscopically, it was found to be composed of hyperplastic lymphoid follicles, lymphocytes, plasma cells, other inflammatory cells and interlaced hyalinised fibrous tissues. In the portal tracts around the lesion, chronic inflammatory cell infiltrates were seen, but no interface hepatitis or lymphoid follicle was observed. No evidence of monoclonality was observed by immunohistochemistry for B and T cell markers, in situ hybridisation for kappa and lambda light chains, and polymerase chain reaction analysis of immunoglobulin heavy chains or T cell receptor beta and gamma gene rearrangements. Bcl-2 immunoreactivity was not observed in the germinal centre. Epstein-Barr virus (EBV) antigen (latent membrane protein-1) and EBV-encoded small RNAs were not detected. A proliferation neither of myofibroblasts nor of cells positive for follicular dendritic cell markers was observed. RLH, formerly known as pseudolymphoma, has been reported of the liver in only 14 cases and is considered to be a differential diagnosis of small nodular lesions of the liver. That RLH has an inflammatory reactive nature, not a neoplastic disposition, and that EBV does not participate in the pathogenesis of RLH is supported by this case.
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PMID:Reactive lymphoid hyperplasia of the liver in a patient with multiple carcinomas: a case report and brief review. 1693 75

The C77G polymorphism in exon A of the human CD45 gene occurs with low frequency in healthy individuals. An enhanced frequency of C77G individuals has been reported in cohorts of patients suffering from multiple sclerosis, systemic sclerosis, autoimmune hepatitis, hepatitis C and human immunodeficiency virus (HIV)-1. C77G individuals overexpress CD45RA isoforms on activated/memory T cells. We have shown previously that aberrant expression of CD45RA isoforms enhances the intensity of T cell receptor (TCR) signalling. Here we report that the C77G polymorphism also influences the responsiveness of T cells to cytokines and alters their adhesion properties. When stimulated by interleukin (IL)-2, C77G T cells proliferated more strongly than wild-type controls and showed accelerated phosphorylation of Janus kinase (Jak1). Furthermore, C77G T cells exhibited a higher tendency to form homotypic aggregates in culture which could be enhanced significantly by antibody-mediated triggering of the variant CD45RA molecules. These data indicate that the changes in CD45 isoform combination resulting from C77G may not only affect TCR signalling but also cytokine-driven T cell responses and cellular adhesion. Altered immune responsiveness may enhance susceptibility of C77G carriers for certain diseases.
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PMID:Altered CD45 isoform expression in C77G carriers influences cytokine responsiveness and adhesion properties of T cells. 1790 20

Natural killer T (NKT) cells generally recognize lipid-antigens presented in the context of the MHC class I-like molecule CD1d. CD1d-restricted NKT cells consist of two broad subsets: Type I, which express an invariant T cell receptor (TCR) and type II, which utilize diverse TCR gene segments. A major type II NKT subset has been shown to recognize a self-glycolipid, sulfatide. Both subsets play important roles in autoimmune diseases, tumor surveillance, and infectious diseases. While type I NKT cells protect from tumor growth by enhancing tumor surveillance, type II NKT cells may suppress anti-tumor immune responses. In a murine autoimmune hepatitis model, type I NKT cells contribute to pathogenesis, whereas activation of sulfatide-reactive type II NKT cells protects from disease. Sulfatide-mediated activation of type II NKT cells results in modification of dendritic cells and induction of anergy in type I NKT cells. Elucidation of this novel pathway of cross-regulation among NKT cell subsets will provide tools for intervention in autoimmune diseases and for designing strategies for effective anti-tumor immunity.
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PMID:Cross-regulation between distinct natural killer T cell subsets influences immune response to self and foreign antigens. 1881 45

Although there is growing evidence that NKT cells play an important role in various immune responses through the invariant T cell receptor, other cell surface molecules responsible for their function are not fully understood. Here we study the role of ICOS, the third member of the CD28 family of costimulatory receptors, in in vivo and in vitro NKT cell responses. To establish its in vivo role in systems dependent on NKT cells, we examined the development of Con A-induced hepatitis in ICOS knockout (ICOS(-/-)) mice. We demonstrated that hepatic injury in ICOS(-/-) mice was greatly suppressed as evidenced by the reduced elevation of serum transaminases, reduced apoptosis of hepatocytes and mild histopathological changes. In investigating the cause of this defect, we first found that the NKT cell population is significantly reduced in the liver and spleen of ICOS(-/-) mice. We made and analyzed mixed bone marrow chimera mice with bone marrow cells from ICOS(+/+) and ICOS(-/-) mice, and demonstrated that the defect in ICOS-mediated costimulation results in a significant defect in the development of NKT cells, especially of Valpha14i NKT cells, in the thymus. When we examined the function of residual NKT cells in ICOS(-/-) mice, we found that their cytokine production following stimulation with alpha-galactosylceramide (alpha-GalCer) was strongly impaired. Based on these findings, we propose that ICOS-mediated costimulation may play a critical role in both the development and the optimal function of NKT cells, and that defective ICOS-mediated costimulation may result in impaired Con A-induced hepatitis in ICOS(-/-) mice.
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PMID:Suppression of Con A-induced hepatitis induction in ICOS-deficient mice. 1991 90

CD4(+) helper T (Th) cells differentiate toward distinct effector cell lineages characterized by their distinct cytokine expression patterns and functions. Multiple Th cell populations secrete IL-22 that contributes to both protective and pathological inflammatory responses. Although the differentiation of IL-22-producing Th cells is controlled by the aryl hydrocarbon receptor (AhR), little is known about the regulatory mechanisms inducing physiological stimulators for AhR. Here, we show that Notch signaling enhances IL-22 production by CD4(+) T cells by a mechanism involving AhR stimulation. Notch-mediated stimulation of CD4(+) T cells increased the production of IL-22 even in the absence of STAT3. CD4(+) T cells from RBP-J-deficient mice had little ability to produce IL-22 through T cell receptor-mediated stimulation. RBP-J-deficient mice were highly susceptible to the detrimental immunopathology associated with ConA-induced hepatitis with little IL-22 production by CD4(+) T cells. Exogenous IL-22 protected RBP-J-deficient mice from ConA-induced hepatitis. Notch signaling promoted production of endogenous stimulators for AhR, which further augmented IL-22 secretion. Our studies identify a Notch-AhR axis that regulates IL-22 expression and fine-tunes immune system control of inflammatory responses.
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PMID:Notch signaling drives IL-22 secretion in CD4+ T cells by stimulating the aryl hydrocarbon receptor. 2023 32


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