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)

CTLs are thought to be major effectors for clearing viruses in acute infections including hepatitis B virus (HBV). Persistent HBV infection is characterized by a lack of or a weak CTL response to HBV, which is thought to reflect tolerance to HBV antigens. In the present study, we found that alpha-galactosylceramide (alpha-GalCer), a ligand for Valpha14-positive NKT cells, strongly enhanced the induction and proliferation of HBV-specific CTLs by HBsAg. In HBsAg transgenic mice, which are thought to be tolerant to HBV-encoded antigens, administration of HBsAg or alpha-GalCer alone failed to induce HBsAg-specific CTLs, but they were induced by co-administration of both compounds. Furthermore, by limiting dilution analysis, we confirmed the existence of HBsAg-specific CTL precursors in the HBsAg transgenic mice immunized with HBsAg and alpha-GalCer. A blocking experiment using antibodies to cytokines and CD40 ligand showed that IL-2 and CD40-CD40L interaction mediate the enhancement of CTL induction caused by alpha-GalCer through NKT cell activation. Our results may open up a new method for clearing the virus from patients with persistent HBV infection.
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PMID:Role of Valpha14+ NKT cells in the development of Hepatitis B virus-specific CTL: activation of Valpha14+ NKT cells promotes the breakage of CTL tolerance. 1848 27

The role of specific CD4(+) T cell subsets in the induction of humoral immune responses in humans is largely unknown. In this study, the generation of hepatitis B surface Ag-specific CD4(+) T lymphocytes following vaccination was closely monitored and characterized at the single-cell level. The appearance and absolute numbers of hepatitis B surface Ag-specific IL-2 producing effector memory CD4(+) T lymphocytes was solely and tightly related to Ab titers reached. This relation remained present many years after vaccination. Subsequently, a relation was found between Ab titers and number of IL-2 producing memory CD4(+) T lymphocytes for various other Ags. These observations matched the findings of an in vitro assay, using different T cell subsets to induce B cell differentiation into IgG-producing plasma cells. By depleting for IL-2 producing memory T cells, we demonstrated that these cells are important for B cell differentiation into IgG-producing plasma cells. Finally, blocking the action of IL-2 with an IL-2R-alpha Ab inhibited the differentiation of B lymphocytes into IgG-producing plasma cells. Based on these findings, we conclude that the development of Ag-specific IL-2-producing memory T cells appears to be essential for the development of IgG-secreting plasma cells in humans.
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PMID:IL-2 producing memory CD4+ T lymphocytes are closely associated with the generation of IgG-secreting plasma cells. 1871 42

(+)-Dapoxetine hydrochloride, (R)-Etodolac; Abatacept, ABT-510, Adalimumab, Agatolimod sodium, Alemtuzumab, Alvocidib hydrochloride, Aminolevulinic acid methyl ester, Aripiprazole, AS01B, AS02B, AS02V, Azacitidine; Becatecarin, Bevacizumab, Bevirimat, Bortezomib, Bremelanotide; CAIV-T, Canfosfamide hydrochloride, CHR-2797, Ciclesonide, Clevidipine; Darbepoetin alfa, Decitabine, Degarelix acetate, Dendritic cell-based vaccine, Denosumab, Desloratadine, DMXB-Anabaseine, Duloxetine hydrochloride, Dutasteride; Ecogramostim, Eicosapentaenoic acid/docosahexaenoic acid, Eletriptan, Enzastaurin hydrochloride, Erlotinib hydrochloride, Escitalopram oxalate, Etoricoxib, Everolimus, Ezetimibe, Ezetimibe/simvastatin; Ferumoxytol, Fesoterodine fumarate, Fulvestrant; Gefitinib, GM-CSF DNA, GSK-690693; H5N1 avian flu vaccine, Hepatitis B hyperimmunoglobulin, Human Fibroblast Growth Factor 1, Hypericin-PVP; Icatibant acetate, Iclaprim, Immunoglobulin intravenous (human), Ipilimumab, ISS-1018; L19-IL-2, Lapuleucel-T, Laropiprant, Liposomal doxorubicin, LP-261, Lumiracoxib, LY-518674; MDV-3100, MGCD-0103, Mirabegron, MyoCell; NASHA/Dx, Niacin/laropiprant; O6-Benzylguanine, Ocrelizumab, Olmesartan medoxomil, Omalizumab; P-276-00, Paclitaxel nanoparticles, Paclitaxel nanoparticles, Padoporfin, Paliperidone, PAN-811, Pegaptanib octasodium, Pegfilgrastim, Pemetrexed disodium, PF-00299804, Pimecrolimus, Prasugrel, Pregabalin; Reolysin, Rimonabant, Rivaroxaban, Rosuvastatin calcium; Satraplatin, SCH-697243,Selenite sodium, Silodosin, Sorafenib, Sunitinib malate; Talarozole, Taxus, Temsirolimus, Tocilizumab, Tolevamer potassium sodium, Tremelimumab, TTP-889; Uracil; V-260, Valsartan/amlodipine besylate, Vardenafil hydrochloride hydrate, Varenicline tartrate, Varespladib, Vitespen, Voclosporin, VX-001; Xience V; Zotarolimus-eluting stent.
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PMID:Gateways to clinical trials. 1880 98

The ideal adjuvants for hepatitis B vaccines should be capable of eliciting both strong humoral and cellular immune responses, especially Th1 cell and cytotoxic T lymphocyte (CTL) responses. However, Alum used as adjuvants in the hepatitis B vaccines currently commercialized offers limitation in inducing cell-mediated response. Therefore, a less hemolytic saponin platycodin D (PD) from the root of Platycodon grandiflorum has been explored for its potential as an alternative adjuvant. In order to compare the adjuvant activity with Alum, antigen-specific cellular and humoral immune responses were evaluated following immunization with a formulation containing hepatitis B surface antigen (HBsAg) adjuvanted with PD and Alum in mice. The Con A-, LPS-, and HBsAg-induced splenocyte proliferation and the serum HBsAg-specific IgG, IgG1, IgG2a, and IgG2b antibody titers in the HBsAg-immunized mice were significantly enhanced by PD (P<0.05, P<0.01 or P<0.001). PD also significantly promoted the production of Th1 (IL-2 and IFN-gamma) and Th2 (IL-10) cytokines and up-regulated the mRNA expression of Th1 cytokines (IL-2 and IFN-gamma) in splenocytes from the mice immunized with HBsAg (P<0.001). Besides, PD remarkably increased the killing activities of natural killer (NK) cells and CTLs from splenocytes in the HBsAg-immunized mice (P<0.001), which may have important implications for vaccination against hepatitis B virus. The results indicated that PD has strong potential to increase both cellular and humoral immune responses and elicit a balanced Th1/Th2 response against HBsAg, and that PD may be the candidates as adjuvants for use in prophylactic and therapeutic hepatitis B vaccine.
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PMID:Platycodin D is a potent adjuvant of specific cellular and humoral immune responses against recombinant hepatitis B antigen. 1904 58

Although the virological features of serologically silent hepadnaviral primary occult infection (POI) have been relatively well recognized in the woodchuck model of hepatitis B virus infection, the characteristics of accompanying immune responses remain unknown. In this study, the kinetics of woodchuck hepatitis virus (WHV)-specific and generalized (mitogen-induced) T-cell proliferative responses and cytokine expression profiles in circulating lymphoid cells and the liver, along with WHV-specific antibody responses, were investigated during experimentally induced POI and subsequent challenge with a liver-pathogenic dose (>10(3) virions) or liver-nonpathogenic dose (50 virions) of the same virus. The data revealed that POI, which does not prompt WHV surface antigenemia, antiviral antibody response, and hepatitis or protect from challenge with a liver-pathogenic virus dose, was accompanied by the appearance of a strong WHV-specific T-cell response directed against multiple viral epitopes that intermittently persisted at low levels for up to 10-months during follow-up. Furthermore, immediately after exposure to a liver-nonpathogenic dose of WHV, lymphocytes acquired a heightened capacity to proliferate in response to mitogenic stimuli and displayed augmented expression of alpha interferon, interleukin-12 (IL-12), and IL-2, but not tumor necrosis factor alpha. Overall, the kinetics of WHV-specific and mitogen-induced T-cell proliferative and cytokine responses in POI were closely comparable to those seen in infection induced by liver-pathogenic viral doses. The data demonstrated that virus-specific T-cell proliferative reactivity is a very sensitive indicator of exposure to hepadnavirus, even to small amounts inducing serologically mute infection. They also showed that hepadnaviral POI is not only a molecularly but also an immunologically identifiable and distinctive entity.
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PMID:Primary occult hepadnavirus infection induces virus-specific T-cell and aberrant cytokine responses in the absence of antiviral antibody reactivity in the Woodchuck model of hepatitis B virus infection. 1919 91

Chronic hepatitis B virus infection is characterized by persistent detectable levels of hepatitis B surface antigen (HBsAg) and HBV DNA in the serum. In contrast, HBsAg is not detectable during occult HBV infection, despite the presence of HBV DNA. An altered host immune response could play a role in the development of occult HBV infection; however, potential differences in immune responses among chronic and occult HBV-infected patients have not been evaluated in vivo. In the current study, we evaluated serum levels of regulatory, apoptotic, and fibrotic/anti-fibrotic cytokines/markers as indicators of immune responses in 25 chronic and 12 occult HBV-infected patients. More than half of the patients in both chronic and occult HBV infection groups had IL-2, IL-4, IL-13, and IFN-gamma levels below detectable limits. In contrast, most patients had detectable levels of IL-8, IL-10, IP-10, sFas, sFasL, and TGF-beta1. Of these, only sFas was significantly different between the two groups, with lower levels observed during occult compared to chronic HBV infection (p=0.01). As a surrogate marker of apoptotic inhibition, decreased sFas during occult HBV infection suggests that apoptosis occurs at different rates in occult compared to chronic HBV infection and therefore, may contribute to persistence of occult HBV infection.
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PMID:Cytokine expression during chronic versus occult hepatitis B virus infection in HIV co-infected individuals. 1962 94

Immune stimulating complexes (ISCOMs) incorporating recombinant hepatitis B surface antigen (rHBsAg) were prepared for induction of humoral and cellular immunity by subcutaneous administration. Prepared ISCOMs were characterized for their size, shape, incorporation efficiency, zeta potential, antigen integrity, antigen conformation and immunogenicity by biophysical and immunological techniques including transmission electron microscopy (TEM), Dynamic light scattering (DLS), SDS-PAGE, fluorescence spectroscopy, in vitro potency test and in vivo humoral and cellular immune stimulatory efficacy in Balb/c mice. Prepared ISCOM particles show characteristic cage like morphology with average size of 44 approximately nm, polydispersity index 0.1, negative zeta potential (-21.7 mV) and antigen association efficiency approximately 39%. Tryptophan emission fluorescence and in vitro potency assay data suggest that association of rHBsAg with ISCOMs results in local electrostatic interactions, motional restriction of tryptophan residues of the protein resulting in reduction of anti-rHBsAg monoclonal antibodies binding affinity. Immunization with rHBsAg ISCOMs resulted in upregulation of specific cellular (IFN-gamma and IL-2) as well as IgG response (IgG2a isotype biased) humoral response in Balb/c mice. Immune responses were significantly higher than those produced by of alum-adsorbed antigen (alum-rHBsAg) after (one booster) (p < 0.001). These data demonstrate that although the conformation of rHBsAg after incorporation into ISCOMs was moderately altered but due to strong adjuvant ability, rHBsAg ISCOMs were highly immunogenic as compared to marketed rHBsAg formulations by subcutaneous route of administration.
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PMID:Evaluation of ISCOMs for immunization against hepatitis B. 1975 Nov 76

The magnitude of the immune response to vaccinations can be influenced by genetic variability. In the present study, we aimed to investigate whether cytokine or cytokine receptor gene polymorphisms were associated with variations in the immune response to childhood vaccination. The study group consisted of 141 healthy infants who had been immunized with hepatitis B vaccine (HBV), 7-valent pneumococcal conjugate (PCV7), and diphtheria, tetanus, acellular pertussis (DTaP) vaccines according to standard childhood immunization schedules. Genotype analysis was performed on genomic DNA using a 5' nuclease PCR assay. Post vaccination total, isotypic, and antigen-specific serum antibody levels were measured using multiplex immunoassays. Significant associations were observed between SNPs in the TNFalpha, IL-12B, IL-4Ralpha, and IL-10 genes and vaccine-specific immune responses (p<0.05). In addition, SNPs in the IL-1beta, TNFalpha, IL-2, IL-4, IL-10, IL-4Ralpha, and IL-12B genes were associated with variations in serum levels of immunoglobulins (IgG, IgA, IgM) and IgG isotypes (IgG1-IgG3) (p<0.05). These data suggest that genetic variations in cytokine genes can influence vaccine-induced immune responses in infants, which in turn may influence vaccine efficacy.
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PMID:Influence of cytokine gene variations on immunization to childhood vaccines. 1981 9

Successful immunotherapy of chronic hepatitis B virus (HBV) infection is expected to be characterized by enhanced activation of immune responses. Combining the specificity of hepatitis B core antigen (HBcAg) cytotoxic T lymphocyte (CTL) epitope, the cell-penetrating property of human immunodeficiency virus-1 (HIV)-Tat peptide, and the adjuvanticity of CpG oligodeoxynucleotides (CpG ODNs) may elicit strong immune responses and therapeutic effects in HBV infection. We synthesized a fusion peptide containing HBcAg18-27 CTL epitope and HIV-Tat(49-57) peptide. The fusion peptide was intramuscularly injected to HBV transgenic mice with CpG ODN as adjuvant at 2-week intervals three times. The percentages of CD3(+), CD4(+) and CD8(+) cells in spleen lymphocytes and the levels of circulating interferon (IFN)-gamma and interleukin (IL)-2 were determined for the evaluation of immune responses and the levels of serum HBV DNA and the expression of hepatitis B surface antigen (HBsAg) and HBcAg in liver tissue were determined for the assessment of therapeutic effects. Our results showed that the synthesized fusion peptide adjuvanted with CpG ODN could induce significant increase of the percentages of CD3(+), CD4(+) and CD8(+) cells and the levels of IFN-gamma and IL-2, indicating the strong immune responses, and reduced HBV DNA levels and decreased expression of HBsAg and HBcAg in liver tissue, suggesting the therapeutic effects. Collectively, our study supports that HBcAg18-27 CTL epitope fused to HIV-Tat(49-57) peptide adjuvanted with CpG ODN may be a promising strategy for immunotherapy of chronic HBV infection.
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PMID:HBcAg18-27 epitope fused to HIV-Tat 49-57 adjuvanted with CpG ODN induces immunotherapeutic effects in transgenic mice. 1988 89

Platycodin D2 (1), a less hemolytic saponin from the root of Platycodon grandiflorum than platycodin D (2), was evaluated for the potential to enhance specific cellular and humoral immune responses to hepatitis B surface antigen (HBsAg) in mice. It significantly increased the concanavalin A (Con A)-, lipopolysaccharide (LPS)-, and HBsAg-induced splenocyte proliferation in HBsAg-immunized mice (P<0.05, P<0.01, and P<0.001, resp.). HBsAg-specific IgG, IgG1, IgG2a, and IgG2b antibody titers in the serum were also markedly enhanced by 1 compared to the HBsAg control group (P<0.01 or P<0.001). Moreover, 1 significantly promoted the production of Th1 (IL-2 and IFN-gamma) and Th2 (IL-4 and IL-10) cytokines from splenocytes in the HBsAg-immunized mice (P<0.001). The adjuvant potential of 1 on splenocyte proliferation, serum HBsAg-specific IgG2a and IgG2b antibody response, as well as Th1-cytokine secretion from splenocytes in the HBsAg-immunized mice was higher than that of Alum. The results suggest that 1 could improve both cellular and humoral immune responses to HBsAg in mice. Hence, 1 might be a promising adjuvant for hepatitis B vaccine with dual Th1- and Th2-potentiating activity.
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PMID:Platycodin D2 improves specific cellular and humoral responses to hepatitis B surface antigen in mice. 2008 84


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