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)

NKT cells are responsible for hepatitis induced either by concanavalin A (Con-A) or alpha-galactosylceramide (alpha-GalCer), and they are also profoundly involved in the generalised Shwartzman reaction (GSR) induced by consecutive injections of interleukin (IL)-12 and lipopolysaccharide (LPS). In the present study, using NC/Nga (NC) mice and SJL mice lacking the Vbeta(+)8 gene, we examined the role of Vbeta(+)8+NKT cells in hepatitis models and in the GSR. The absence of Vbeta(+)8+NKT cells in the liver mononuclear cells (MNC) was confirmed by the alpha-GalCer/CD1d/Ig dimer. Unexpectedly, other dimer+NKT cells including Vbeta7(+)NKT cells in these mice were found to decrease in comparison to that of C57BL/6 mice. No significant hepatocyte injury was observed after alpha-GalCer or Con-A administration in either mice. The serum interferon (IFN)-gamma, IL-4 and tumour necrosis factor (TNF) levels did not increase in these mice after alpha-GalCer injection, however these cytokines substantially increased after Con-A administration, thus suggesting that the roles of NKT cells differ between the two hepatitis models. However, in GSR, although neither mice showed lower IFN-gamma levels after a priming IL-12 injection, they showed TNF levels comparable to those in normal mice after LPS injection, and thus resulted in a decreased but substantial mortality. Although liver MNC from IL-12-injected SJL mice showed an impaired antitumour cytotoxicity, liver MNC of NC mice exhibited a greater antitumour cytotoxicity than that of C57BL/6 mice because liver NK cells proportionally increased in NC mice. These results confirm the critical role that Vbeta8(+)NKT cells play in both liver and multi-organ injury.
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PMID:Mice deficient in Vbeta8+NKT cells are resistant to experimental hepatitis but are partially susceptible to generalised Shwartzman reaction. 1738 Mar 3

The underlying mechanisms for earlier hepatitis B e antigen (HBeAg) seroconversion in patients with chronic hepatitis B virus (HBV) genotype B when compared with genotype C are unknown. We aimed to determine whether there were any differences in the T helper (Th) responses during hepatitis flares in HBeAg-positive patients with genotypes B and C. Proliferative response measured by (3)H-thymidine uptake and Th responses measured by Enzyme-Linked Immunosorbent Spot assays for interleukin (IL)-2, interferon-gamma (IFN-gamma), IL-4, IL-5 and IL-10 were performed in 10 patients with genotype B and 10 with genotype C with hepatitis flares. HBV genotypes, core promoter, precore mutations, sequence of HBV core region and HBV DNA levels were determined. There was no difference in the HBV DNA levels during hepatitis flares between patients with genotypes B and C. Patients with genotype B had a significantly higher number of IFN-gamma producing cells [with hepatitis B core antigen (HBcAg) stimulation] and lower number of IL-10 producing cells (with HBcAg and HBeAg stimulation) compared with patients with genotype C (P = 0.011, =0.043, <0.001 respectively). There was a trend (P = 0.058) that patients with genotype B had a higher cumulative rate of HBeAg seroconversion. Patients with precore mutants also had a significantly higher number of IFN-gamma producing cells (with HBcAg stimulation) and lower number of IL-10 producing cells (with HBeAg stimulation) compared to patients without precore mutant (P = 0.038, =0.016 respectively). HBV genotype B induces a greater Th1 and lesser Th2 response than genotype C. This provides immunologic evidence for the higher chance of HBeAg seroconversion in patients with genotype B.
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PMID:Difference in T helper responses during hepatitis flares in hepatitis B e antigen (HBeAg)-positive patients with genotypes B and C: implication for early HBeAg seroconversion. 1738 19

Woodchucks infected with the woodchuck hepatitis virus (WHV) is the best available animal model for testing the immunotherapeutic effects of dendritic cells (DCs) in the setting of a chronic infection, as woodchucks develop a persistent infection resembling that seen in humans infected with the hepatitis B virus. In the present study, DCs were generated from woodchuck peripheral blood mononuclear cells (wDCs) in the presence of human granulocyte macrophage colony-stimulating factor (hGM-CSF) and human interleukin 4 (hIL-4). After 7 days of culture, cells with morphology similar to DCs were stained positively with a cross-reactive anti-human CD86 antibody. Functional analysis showed that uptake of FITC-dextran by wDCs was very efficient and was partially inhibited after LPS-induced maturation. Furthermore, wDCs stimulated allogenic lymphocytes and induced proliferation. Moreover, wDCs were transduced efficiently with a human adenovirus serotype 5 for the expression of beta-galactosidase. Following transduction and in vivo administration of such DCs into woodchucks, an antigen-specific cellular immune response was induced. These results demonstrate that wDCs can be generated from the peripheral blood. Following transfection with a recombinant adenovirus wDCs can be used as a feasible and effective tool for eliciting WHV-specific T-cell responses indicating their potential to serve as prophylactic and therapeutic vaccines.
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PMID:Woodchuck dendritic cells generated from peripheral blood mononuclear cells and transduced with recombinant human adenovirus serotype 5 induce antigen-specific cellular immune responses. 1738 94

IL-12 is essential for invariant NKT (iNKT) cells because it can maintain a functionally active population and promote a cytokine profile that is assumed to be mainly of the pro-Th1 type. We used the murine concanavalin A (Con A)-induced hepatitis model, in which iNKT cells, IL-12, IL-4, and IFN-gamma are equally requisite, to reevaluate this issue. We demonstrate that IL-12 interacts directly with iNKT cells, contributes to their recruitment to the liver, and enhances their IL-4 production, which is essential for disease onset. IL-12-deficient mice were less susceptible to experimental hepatitis and their iNKT cells produced less IL-4 than their wild-type counterpart. A normal response could be restored by IL-12 injection, revealing its importance as endogenous mediator. In accordance with this observation, we found that iNKT cells expressed the IL-12R constitutively, in contrast to conventional T cells. Furthermore, the physiological relevance of our data is supported by the lower susceptibility to disease induction of NOD mice, known for their inherent functional and numerical abnormalities of iNKT cells associated with decreased iNKT cell-derived IL-4 production and low IL-12 secretion. Taken together, our findings provide the first evidence that IL-12 can enhance the immune response through increased IL-4 production by iNKT cells, underscoring once more the functional plasticity of this subset.
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PMID:The Pro-Th1 cytokine IL-12 enhances IL-4 production by invariant NKT cells: relevance for T cell-mediated hepatitis. 1744 24

The purpose of the work was to study the levels of interleukin-1beta (IL-1beta), IL-2, IL-4, IL-6, tumor necrosis factor a (TNF-alpha), interferon alpha (IF-alpha), interferon gamma (IF-gamma), and the parameters of T-cell immunity in 70patients with acute hepatitis C (AHC). The content of cytokines in peripheral blood was determined by immune-enzyme technique using test systems produced by Proteinovy Kontur (Saint-Petersburg). Evaluation of T-cell reacting (CD4, CD8, CD16, and CD20) was done using a kit of mono- and polyclonal antibodies for human T-lymphocyte, B-lymphocyte, T-helper, T-killer-suppressor, and NK-lymphocyte detection with immunofluorescence technique, produced by Sorbent, Podolsk. Assessment of cytokine spectrum was of a prognostic value. Primary examination revealed high levels of IL-2, IFgamma, CD4, and CD16 and normal levels of IL-4 in most patients who recovered later. These changes characterized a more pronounced activity of Th1 lymphocytes and suppression of Th2 mediator synthesis, which favored the formation of a strong immune response and led to viral elimination. Primary examination usually did not find a significant elevation of pro-inflammatory mediators level, but found high levels of IL-4, CD8, and CD20 in AHC patients whose disease later acquired a chronic form. These features of the spectrum of immune response mediators reflected a more prominent activity of Th2-lymphocytes, suppressing Th1-effector mechanisms, which favored active viral replication and the formation of chronic C hepatitis.
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PMID:[Indices of cell immunity and immune system mediators in patients with acute HCV infection]. 1768 96

We describe a 26-year-old female referred to us because of recurrent bacterial pneumonia. Her immunoglobulin profile on admission was; IgG 1920 mg/l, IgA 60 mg/l, IgM 260 mg/l, IgD below 20 mg/l, IgE below 1 kU/l. Antinuclear antibodies, EBV VCA IgM, anti-parvovirus B19 IgM antibodies and hepatitis infection markers were all negative. Bone marrow aspiration revealed normal cellularity without abnormal cells, especially plasma cell proliferation. No rearrangement for IgH and TCR was observed as determined by Southern blot analysis. By the given data, a diagnosis of common variable immunodeficiency (CVID) was made. The genesis of this disease remained unclear. In this study, proliferation and immunoglobulin production with or without several stimulators were examined. Proliferation stimulated by PHA, Con-A, LPS, or IL-2 was decreased compared to that of healthy individuals. Immunoglobulin production after stimulation with several agents was quite low. Interestingly, however, IL-2 or IL-4 could increase IgM production on 6 days culture significantly. These results indicate that IL-2 or IL-4 possibly restore T cell responses to several antigens and induce B cell differentiation.
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PMID:Partial restoration of immunoglobulin production by cytokines in common variable immunodeficiency. 1782 53

The authors studied the levels of cytokines (interleukin (IL)-1, IL-2, IL-4, IL-6, and interferon-gamma (IFN-gamma)) and cell response to HBV and HCV in the dynamics in patients with acute mixed hepatitis (B+C) who recovered or became chronically ill, as well as before and after treatment of hepatitis C. Patients who later recovered had high levels of IL-2 and IFN-gamma during the acute phase of the disease, and displayed T-lymphocyte sensitization to HbeAg, Hbcore Ag, and the non-structural protein HCV NS3. A significant elevation of IL-2 level and, especially, IFN-gamma level, as well as the appearance of T-lymphocyte response to HCV NS3, HCVcore Ag, and HCV NS4 was observed during antiviral therapy.
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PMID:[Clinical significance of cytokine level and T-cell lymphocyte response to B and C hepatic viral antigens in patients with type C and B+C hepatitis receiving antiviral therapy]. 1788 15

During acute viral hepatitis, the intrahepatic tolerance sustained by immunosuppressive cytokines such as interleukin (IL)-4, IL-10, transforming growth factor (TGF)-beta and prostaglandin E2 (PGE2), produced by Kupffer cells (KC), liver sinusoidal endothelial cells (LSEC), natural killer (NK) T cells and natural regulatory T cells may be disturbed. NK cells are recruited normally in the liver and produce interferon (IFN)-gamma to control viral replication. The use of mouse hepatitis virus type 3 (MHV3) attenuated variants showing selected tropisms for KC or LSEC have allowed determining their roles in the disturbances of immune tolerance during viral hepatitis. Groups of C57BL/6 mice were infected with the pathogenic L2-MHV3 (KC+, LSEC+), low attenuated 51.6-MHV3 (KC+, LSEC-) or high attenuated CL12-MHV3 (KC-, LSEC-) variants for the first 3 days. Results showed that IL-10, TGF-beta and PGE2 production in the liver decreased in L2-MHV3-infected mice and increased in 51.6-MHV3- and CL12-MHV3-infected mice. The ratio of IFN-gamma/IL-4 in liver decreased in L2-MHV3-infected mice, while it was not (or low) altered in mice infected with the attenuated MHV3 variant mice. Phenotypic analysis of intrahepatic mononuclear cells revealed that apoptotic NK and NK T cells increased in mice infected with the L2-MHV3, but were minor in 51.6-MHV3- and CL12-MHV3-infected mice. The numbers of CD4+ forkhead box P3+ cells increased in the livers from low pathogenic CL12-MHV3 and YAC-MHV3-infected mice. These results indicate that viral permissivity of KC and LSEC is involved in the decrease of IL-10 and PGE2, while KC may play an additional role in the apoptosis of NK and NK T cells during acute viral hepatitis.
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PMID:Intrahepatic endothelial and Kupffer cells involved in immunosuppressive cytokines and natural killer (NK)/NK T cell disorders in viral acute hepatitis. 1833 88

TNF-alpha, IFN-gamma, IL-4, and MIP-2 are known to be involved in Con A-induced hepatitis. Although Kupffer cells are reportedly involved in TNF-alpha production, it is largely unknown whether or not Kupffer cells also play a role in the production of other cytokines, such as IFN-gamma, IL-4, and MIP-2. In this study we examined the liver injury and the levels of plasma cytokines, including above four cytokines, KC, and IL-10 in Kupffer cell-depleted mice obtained through administration of liposome-encapsulated dichloromethylene bisphosphonate. The liver injury was significantly suppressed in Kupffer cell-depleted mice, as assessed as to the plasma ALT level and histochemistry. The cytokine levels were also significantly suppressed in such mice except for those of IFN-gamma, which was slightly suppressed at 12h, and IL-10, which was not significantly suppressed at any time. Apoptosis was also significantly suppressed in such mice, as found immunohistochemically with anti-ssDNA Ab. Taken together, these results suggest that Kupffer cells are involved in the production of MIP-2, KC, IL-4, and TNF-alpha in Con A-induced hepatitis, thereby contributing to the liver injury either directly or indirectly.
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PMID:Effects of Kupffer cell-depletion on Concanavalin A-induced hepatitis. 1837 9

The histological hallmark of autoimmune hepatitis (AIH) is a dense portal mononuclear cell infiltrate that invades the surrounding parenchyma and comprises T and B lymphocytes, macrophages, and plasma cells. An unknown but powerful stimulus must be promoting the formation of this massive inflammatory cellular reaction that is likely to initiate and perpetuate liver damage. An autoimmune attack can follow different pathways to inflict damage on hepatocytes. Liver damage is likely to be orchestrated by CD4(+) T lymphocytes recognizing an autoantigenic liver peptide. To trigger an autoimmune response, the peptide must be embraced by an HLA class II molecule and presented to naive CD4(+) T helper (Th0) cells by professional antigen presenting cells, with the co-stimulation of ligand-ligand fostering interaction between the two cells. Th0 cells become activated, differentiate into functional phenotypes according to the cytokines prevailing in the microenvironment and the nature of the antigen, and initiate a cascade of immune reactions determined by the cytokines produced by the activated T cells. Th1 cells, arising in the presence of the macrophage-derived interleukin (IL) -12, secrete mainly IL-2 and interferon-gamma (IFN-gamma), which activate macrophages, enhance expression of HLA class I (increasing liver cell vulnerability to a CD8(+) T cell cytotoxic attack), and induce expression of HLA class II molecules on hepatocytes. Th2 cells, which differentiate from Th0 if the microenvironment is rich in IL-4, produce mainly IL-4, IL-10, and IL-13 which favour autoantibody production by B lymphocytes. Physiologically, Th1 and Th2 antagonize each other. Th17 cells, a recently described population, arise in the presence of transforming growth factor beta (TGF-beta) and IL-6 and appear to have an important effector role in inflammation and autoimmunity. The process of autoantigen recognition is strictly controlled by regulatory mechanisms, such as those exerted by CD4(+)CD25(+) regulatory T cells, which derive from Th0 in the presence of TGF-beta, but in the absence of IL-6. If regulatory mechanisms fail, the autoimmune attack is perpetuated. Over the past three decades different aspects of the above pathogenic scenario have been investigated. In particular, a defect in immunoregulation affecting CD4(+)CD25(+) regulatory T cells (T-regs) has been demonstrated in AIH, particularly at diagnosis or during relapse. Advances in the study of autoreactive T cells have occurred mostly in AIH type 2, since the knowledge that CYP2D6 is the main autoantigen has enabled the characterization of both CD4 and CD8 T cells targeting this cytochrome. CD4 T cells from patients with type 2 AIH positive for the predisposing HLA allele DRB1*0701 recognize seven regions of CYP2D6, five of which are also recognized by CD8 T cells. High numbers of IFN-gamma producing CD4 T cells and CD8 T cells are associated with biochemical evidence of liver damage, suggesting a combined cellular immune attack.
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PMID:Aetiopathogenesis of autoimmune hepatitis. 1852 28


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