Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019163 (hepatitis B)
 38,309 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have studied the proliferation and CD40 antigen expression of lymphocytes, and the cytotoxicity to monocytes, of antisense phosphorothioate oligodeoxynucleotides complementary to the SP II promoter of HBV mRNA (sequence I) and the X gene (sequence II) in patients with chronic hepatitis B. The oligo sequence I stimulated proliferation of both T and, to a lesser extent, B cells. The percentage of cells expressing CD40 in T and B cell co-cultures increased from 4.2% to 13.8% after oligo stimulation in patients, while it increased form 4.7% to 48.6% in healthy controls. The sense sequence (sequence III) of the X gene also enhanced the expression of CD40 antigen in patients with hepatitis B. The proportion of CD40 cells (26%) in a resting B-cell preparation from hepatitis B patients decreased to zero after a 5-day culture with sequence I, but IgG levels in the culture supernatant increased. The cytotoxic properties of monocytes were not influenced by the oligos. These findings indicate that antisense oligos against hepatitis B virus (HBV) have mitogenic effects on the proliferation of human lymphocytes in a non-specific manner and may activate T cells to express CD40 antigen.
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PMID:Stimulation of human lymphocyte proliferation and CD40 antigen expression by phosphorothioate oligonucleotides complementary to hepatitis B virus genome. 887 77

While the elimination of hepatitis B virus (HBV) is a common phenomenon at the end of the acute phase of disease, the persistence of HBV is characteristic for chronic hepatitis (CHB). Recent evidence indicates that the elimination of HBV is achieved by FAS/FAS-L induced apoptosis of infected hepatocytes. The aim of this study was to test the hypothesis that HBV persistence in the hepatocytes of CHB patients is due to the delayed onset of apoptosis caused by altered FAS/FAS-L interactions between lymphocytes and hepatocytes. The expression of FAS, FAS-L, BAX, BCL-2, ICE and PCNA in the liver biopsies of 55 patients (14 HBsAg positive, 20 patients with alcoholic hepatopathy, 21 patients with other hepatopathies) was tested by immunohistochemistry. Apoptosis of hepatocytes was evaluated by morphological as well as by TUNEL method. The results were correlated with a grading/staging score and analysed statistically using a one way analysis of variance and the Duncan test. Significantly highernumbers of BAX positive hepatocytes were observed in HBsAg positive patients when compared to control groups. Similarly, both BAX and FAS positive lymphocytes were more frequent in HBsAg positive patients. FAS-L positive lymphocytes and hepatocytes were numerous in all patient groups. Increased numbers of BAX positive hepatocytes in CHB may reflect the increased readiness of these cells to undergo apoptosis. However, the increased numbers of both BAX and FAS positive lymphocytes in CHB suggest that these cells may be particularly sensitive to FAS-L mediated apoptosis potentially resulting in lowered viability of these lymphocytes. This may explain, at least in part, the defective removal of virus-infected cells in chronic hepatitis. However, we cannot rule out the possibility that survival of hepatocytes during CHB may be due to other mechanisms such as defects in apoptosis activation triggered by CD40, defects involving DNase and/or other caspases downstream in the apoptotic cascade within these cells, or to defects in CTL function.
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PMID:Apoptosis-related proteins, BCL-2, BAX, FAS, FAS-L and PCNA in liver biopsies of patients with chronic hepatitis B virus infection. 1093 89

Virus-like particles (VLPs) are known to induce strong Ab responses in the absence of adjuvants. In addition, VLPs are able to prime CTL responses in vivo. To study the efficiency of this latter process, we fused peptide p33 derived from lymphocytic choriomeningitis virus to the hepatitis B core Ag, which spontaneously assembles into VLPs (p33-VLPs). These p33-VLPs were efficiently processed in vitro and in vivo for MHC class I presentation. Nevertheless, p33-VLPs induced weak CTL responses that failed to mediate effective protection from viral challenge. However, if APCs were activated concomitantly in vivo using either anti-CD40 Abs or CpG oligonucleotides, the CTL responses induced were fully protective against infection with lymphocytic choriomeningitis virus or recombinant vaccinia virus. Moreover, these CTL responses were comparable to responses generally induced by live vaccines, because they could be measured in primary ex vivo (51)Cr release assays. Thus, while VLPs alone are inefficient at inducing CTL responses, they become very powerful vaccines if applied together with substances that activate APCs.
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PMID:Critical role for activation of antigen-presenting cells in priming of cytotoxic T cell responses after vaccination with virus-like particles. 1188 58

Dendritic cell (DC)-dependent activation of liver NKT cells triggered by a single i.v. injection of a low dose (10-100 ng/mouse) of alpha-galactosyl ceramide (alphaGalCer) into mice induces liver injury. This response is particularly evident in HBs-tg B6 mice that express a transgene-encoded hepatitis B surface Ag in the liver. Liver injury following alphaGalCer injection is suppressed in mice depleted of NK cells, indicating that NK cells play a role in NK T cell-initiated liver injury. In vitro, liver NKT cells provide a CD80/86-dependent signal to alphaGalCer-pulsed liver DC to release IL-12 p70 that stimulates the IFN-gamma response of NKT and NK cells. Adoptive transfer of NKT cell-activated liver DC into the liver of nontreated, normal (immunocompetent), or immunodeficient (RAG(-/-) or HBs-tg/RAG(-/-)) hosts via the portal vein elicited IFN-gamma responses of liver NK cells in situ. IFN-beta down-regulates the pathogenic IL-12/IFN-gamma cytokine cascade triggered by NKT cell/DC/NK cell interactions in the liver. Pretreating liver DC in vitro with IFN-beta suppressed their IL-12 (but not IL-10) release in response to CD40 ligation or specific (alphaGalCer-dependent) interaction with liver NKT cells and down-regulated the IFN-gamma response of the specifically activated liver NKT cells. In vivo, IFN-beta attenuated the NKT cell-triggered induction of liver immunopathology. This study identifies interacting subsets of the hepatic innate immune system (and cytokines that up- and down-regulate these interactions) activated early in immune-mediated liver pathology.
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PMID:Activating immunity in the liver. II. IFN-beta attenuates NK cell-dependent liver injury triggered by liver NKT cell activation. 1193 27

In this study we evaluated the ability of activated intrahepatic APCs to inhibit hepatitis B virus (HBV) replication in transgenic mice. Intrahepatic APCs were activated by administration of an anti-CD40 agonistic mAb (alphaCD40). We showed that a single i.v. injection of alphaCD40 was sufficient to inhibit HBV replication noncytopathically by a process associated with the recruitment of dendritic cells, macrophages, T cells, and NK cells into the liver and the induction of inflammatory cytokines. The antiviral effect depended on the production of IL-12 and TNF-alpha by activated APCs; however, it was mediated primarily by IFN-gamma produced by NK cells, and possibly T cells, that were activated by IL-12. Collectively, these results suggest that activated APCs can directly produce antiviral cytokines (IL-12, TNF-alpha) and trigger the production of other cytokines (i.e., IFN-gamma) by other cells (e.g., NK cells and T cells) that do not express CD40. These results provide insight into a hitherto unsuspected antiviral function of intrahepatic APCs, and they suggest that therapeutic activation of APCs may represent a new strategy for the treatment of chronic HBV infection.
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PMID:Activated intrahepatic antigen-presenting cells inhibit hepatitis B virus replication in the liver of transgenic mice. 1239 Dec 36

Dendritic cell (DC) maturation is critical for the induction of antigen-specific T lymphocyte responses and may be essential for the development of human vaccines relying on T cell immunity. We investigated the effects on human DC of OM-197, a synthetic pseudodipeptide derived from amino acids, linked to three fatty acid chains and devoid of endotoxin properties. OM-197 upregulated the expression of HLA-DR, CD80, CD86, CD83, CD40 and CD54 at the surface of myeloid DC naturally present in blood as well as of DC generated in vitro from monocytes using IL-4 and GM-CSF. OM-197 also induced the release of IL-12 and TNF-alpha from DC. Finally, DC incubated with OM-197 after pulsing with hepatitis B surface antigen (HBs Ag) induced in vitro expansion of IFN-gamma-secreting HBs Ag-specific CD4(+) T lymphocytes from naive individuals. Taken together, these data identify OM-197 as a potential vaccine adjuvant for the induction of Th1-type responses.
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PMID:OM197-MP-AC induces the maturation of human dendritic cells and promotes a primary T cell response. 1263 19

Clearance of hepatitis B virus infection (HBV) infection implies a polyclonal vigorous T-helper 1 (Th1) and cytotoxic T-lymphocyte (CTL) response. Interleukin-18 (IL-18), a monokine that shares functional abilities with IL-12, is a potent inductor of interferon-gamma (IFN-gamma) by Th1 and natural killer (NK) cells. However, the role and regulation in HBV infection of IFN-gamma have not been defined. This study therefore sought to determine hepatitis B core antigen (HBcAg)-mediated regulation of IL-18 production in peripheral blood mononuclear cells (PBMCs) from healthy controls (HC) and patients with chronic hepatitis B (CHB) or acute hepatitis B (AHB); 31 HC, 27 patients with CHB and 8 patients with AHB infection were included in the study. HBcAg-mediated induction of IL-18 was determined by quantitative reverse transcription-polymerase chain reaction (RT-PCR) and specific enzyme-linked immunosorbent assay (ELISA). HBcAg induced IL-18 gene transcription and dose-dependent secretion of mature IL-18 protein in HC, CHB, and AHB. HBcAg-dependent IL-18 levels were abrogated by inhibition of Caspase-1, but not by blockade of CD40-CD154 interaction. Serum levels of IFN-gamma correlated inversely with viremia in patients with CHB (rho = - 0.54, P < 0.05), but not with serum levels of IL-12 or IL-18. Interestingly, in PBMCs of HBeAg-negative patients, HBcAg induced significantly higher amounts of IL-18 than in those of HBeAg-positive patients. A variant, lacking the histone-like arginine-rich domain, did not induce IL-18 in either HC or CHB in vitro. Taken together, these results indicate that HBcAg induces IL-18 secretion by induction of Caspase-1. Differential regulation in HBeAg-negative and positive patients suggests an important role of IL-18 in CHB infection.
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PMID:Hepatitis B core antigen is a potent inductor of interleukin-18 in peripheral blood mononuclear cells of healthy controls and patients with hepatitis B infection. 1285 6

CD40/CD154 interaction is essential for both humoral and cellular immune response. We investigated whether this interaction could be altered in patients with kidney failure who are known to present an impaired immune response. To that aim, we measured the levels of the soluble form of CD40 (sCD40), which is known to interfere with CD40/CD154 interaction, in 43 chronic renal failure patients, 162 hemodialysed patients, and 83 healthy donors. Uraemic and haemodialysed patients presented a three- and fivefold increase, respectively, of the antagonist soluble form of CD40 in their serum, when compared to healthy subjects. Serum sCD40 levels correlated with those of creatinine in uraemic non-haemodialysed patients. While sCD40 is widely excreted in urine of healthy individuals, it is not eliminated by dialysis sessions on classic membranes. The return to a normal kidney function in nine haemodialysed patients who received renal transplantation, leads to a rapid decrease of serum sCD40 levels. This natural sCD40 exhibited multimeric forms and was able to inhibit immunoglobulin production by CD154-activated B lymphocytes in vitro. Furthermore, the positive correlation we observed between the serum levels of sCD40 and the deficient response to hepatitis B vaccination in uraemic patients suggests that sCD40 also compromises the humoral response in vivo.
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PMID:Potential role of soluble CD40 in the humoral immune response impairment of uraemic patients. 1294 Nov 50

The Nef gene is a major determinant of HIV-1 pathogenicity. Several immunomodulatory functions have been reported for Nef, including down-regulation of CD4 and class I MHC in T-lymphocytes, and the ability to enhance viral transmission from macrophages and dendritic cells (DC) to T-lymphocytes. In this study, HIV-1 (SF2 strain) Nef was expressed in human monocyte-derived dendritic cells, using an adenovirus based delivery system. Nef expression resulted in decreased CD4 levels, but no change to class I MHC, and no impairment in the ability of DC to stimulate recall PPD responses, mixed leukocyte responses, or hepatitis B-specific CD8 responses. The adenovirus vector itself stimulated a strong recall CD4 response in all individuals tested, and also induced up-regulation of class I MHC, CD86 and CD40 on the dendritic cell surface. The study provides no evidence that HIV Nef impairs the function of human dendritic cells, and suggests that delivery of Nef to dendritic cells may be one strategy with which to stimulate an HIV-1 immune response.
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PMID:The functional consequences of delivery of HIV-1 Nef to dendritic cells using an adenoviral vector. 1467 Mar 36

Cytotoxic T lymphocytes (CTL) are essential for control of primary infections by many pathogens and in particular by non-cytopathic viruses. It has been proposed that long-term maintenance of CTL memory and control of lymphocytic choriomeningitis virus (LCMV) is dependent upon the presence of T helper cells and interaction of antigen-presenting cells and CTL via CD40 and its ligand CD40L. However, we demonstrate here that CD40-CD40L interaction maintains CTL memory by induction of virus-specific antibodies. In fact, loss of CTL memory responses and spread of virus in mice lacking CD40 or its ligand is prevented by repetitive therapeutic injections of LCMV-specific antibodies. This indicates that antibodies are essential for long-term control of non-cytopathic virus and to maintain protective memory. Transfer of neutralizing antibodies or induction of antibodies by therapeutic vaccination within weeks after infection may therefore prove beneficial for the treatment of chronic virus infections such as HIV, hepatitis B, and hepatitis C. See accompanying article http://dx.doi.org/10.1002/eji.200324844
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PMID:Maintenance of memory CTL responses by T helper cells and CD40-CD40 ligand: antibodies provide the key. 1476 35


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