Hepatitis: Kanto T

Kanto T, Hayashi N. · No affiliation provided · J Gastroenterol. · Pubmed #15338382 No free full text.

This publication has no abstract.

Kanto T. · Department of Gastroenterology, Osaka University Graduate School of Medicine, Suita, Japan. · Front Biosci. · Pubmed #18508652 No free full text.

Abstract: Dendritic cells (DCs) sense virus via toll-like receptors (TLR) or retinoic acid inducible gene-I (RIG-I) and evoke a cascade of immune reactions. In myeloid DC (MDC) from hepatitis C virus (HCV)-infected patients, the levels of TLR/RIG-I-mediated IFN-beta or TNF-alfa induction are lower than those in uninfected donors, suggesting that their signal transduction in MDC is impaired. Dendritic cells in HCV infection are unresponsive to interferon (IFN)-alfa, thus failing to enhance MHC class-I related chain A/B and subsequent NK cell activation. Alternatively, NK cells from the patients down-regulate DC in the presence of HLA-E-expressing hepatocytes by secreting IL-10 and TGF-beta1. Such functional alteration of NK cells in HCV infection is ascribed to the enhanced expression of NKG2A/CD94. Activated NKT cells from the patients produce higher levels of IL-13 but comparable IFN-gamma with those from controls, showing their bias to Th2-type. In pegylated IFN-alfa/ribavirin therapy for chronic hepatitis C, improved DC function is related with successful HCV eradication. In conclusion, cross-talks among DCs and innate lymphocytes are critical in shaping immune response against HCV, either spontaneously or therapeutically.

Kanto T, Hayashi N. · Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Osaka. · Intern Med. · Pubmed #16543687 links to  free full text

Abstract: Hepatitis C virus (HCV) infection is one of the major causes of chronic liver disease worldwide. The critical role of innate as well as adaptive immunity has been reported in HCV persistence and liver injury. In the early phase of acute infection, HCV continues to replicate in the liver, suggesting the HCV capability of inhibiting innate immunity. The sustained, vigorous and multiepitope-specific CD4+ and CD8+ T cell responses are essential for spontaneous HCV clearance. HCV-specific CD8+ T cells are primary elements for HCV clearance by inducing hepatocyte apoptosis, in which Fas/CD95 is fundamentally involved. However, once HCV persistency develops, HCV utilizes multifaceted arms to subvert various immune effectors. During IFNalpha-based therapy, the enhancement of HCV-specific CD4+ T cell response followed by HCV eradication has been reported, however, it remains obscure whether the therapeutic HCV clearance is able to restore the durable immune competency to HCV. Further investigation is still warranted to establish the means to direct HCV-specific immune responses in the desired way.

Kanto T, Hayashi N. · Department of Dendritic Cell Biology and Clinical Application, Osaka University Graduate School of Medicine. · Nippon Rinsho. · Pubmed #15359787 No free full text.

This publication has no abstract.

Kanto T, Hayashi N. · Department of Molecular Therapeutics, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, 565-0871 Suita, Japan. · J Gastroenterol. · Pubmed #15338363 No free full text.

This publication has no abstract.

Hayashi N, Kanto T, Hosui A, Sugimoto Y, Okawa K, Takehara T, Sasaki Y. · No affiliation provided · Nippon Naika Gakkai Zasshi. · Pubmed #12577933 No free full text.

This publication has no abstract.

Itose I, Kanto T, Inoue M, Miyazaki M, Miyatake H, Sakakibara M, Yakushijin T, Oze T, Hiramatsu N, Takehara T, Kasahara A, Katayama K, Kato M, Hayashi N. · Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Japan. · J Med Virol. · Pubmed #17385691 No free full text.

Abstract: A combination of pegylated interferon alpha (PEG-IFNalpha) and ribavirin has been used widely. Enhancement of immune response against hepatitis C virus (HCV) is known to be involved in the efficacy of the combination therapy. The aim of the study was to elucidate whether the frequency or function of immunocompetent blood cells is related to the outcome of the therapy. Twenty-five chronic hepatitis C patients with high viral load of HCV genotype 1 who underwent 48 weeks of PEG-IFNalpha2b and ribavirin therapy were examined. During the treatment, frequencies of dendritic cell subsets, helper T cell subsets, and NK cells were phenotypically determined. In some patients, the ability of dendritic cells to stimulate allogeneic CD4(+)T cells was examined at the end and after the therapy. Among the 25 patients, 11 showed a sustained virological response, 11 a transient response, and 3 no response. In comparison with sustained virological responders, non-sustained virological responders showed impaired dendritic cell function at the end and after the treatment. The transient responders showed a decline of plasmacytoid dendritic cell frequency from Weeks 1-12 and impaired dendritic cell function as well. Even in patients who attained negative serum HCV RNA at Week 12, the transient responders showed a significant decrease of plasmacytoid dendritic cell frequency and impaired dendritic cell function. In conclusion, in PEG-IFNalpha and ribavirin combination therapy for chronic hepatitis C patients, the early-phase plasmacytoid dendritic cell frequency and/or end-of-treatment dendritic cell function are related to the virological outcome of the therapy.

Kurashige N, Hiramatsu N, Ohkawa K, Yakushijin T, Kiso S, Kanto T, Takehara T, Kasahara A, Doi Y, Yamada A, Oshita M, Mita E, Hagiwara H, Nagase T, Yoshihara H, Hayashi E, Imai Y, Kato M, Kashihara T, Hayashi N. · Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan. · J Gastroenterol. · Pubmed #19387534 No free full text.

Abstract: PURPOSE: The antiviral effect of adefovir dipivoxil (ADV) added to ongoing lamivudine (LAM) treatment for LAM-resistant chronic hepatitis B (CHB) differs among patients. We investigated clinical factors affecting the response to ADV therapy in LAM-resistant CHB. METHODS: The subjects were 75 LAM-resistant CHB patients treated with ADV in addition to LAM. Virological response (VR) was defined as HBV DNA clearance (<2.6 logcopies/ml) at 12 months after the start of ADV therapy. Clinical factors contributing to VR were examined by univariate and multivariate analyses. RESULTS: Lower HBV DNA at baseline and negative hepatitis B e antigen (HBeAg) were significant factors affecting VR in univariate analysis. In multivariate analysis, lower HBV DNA at baseline (P = 0.005), negative HBeAg (P = 0.009), and higher ALT (P = 0.036) were significant independent factors contributing to VR. In HBeAg-positive patients, HBV DNA clearance was more frequently observed during ADV therapy in patients with baseline HBV DNA < or = 7.0 logcopies/ml than in those with baseline HBV DNA >7.0 logcopies/ml. By contrast, the link of lower HBV DNA at baseline to better therapeutic response was not evident in HBeAg-negative patients. CONCLUSION: In ADV therapy added to ongoing LAM treatment for LAM-resistant CHB, lower baseline HBV DNA and negative HBeAg contributed to a better antiviral effect. Addition of ADV should be done promptly before marked increase in HBV DNA, especially in CHB patients showing LAM resistance positive for HBeAg.

Kurokawa M, Hiramatsu N, Oze T, Mochizuki K, Yakushijin T, Kurashige N, Inoue Y, Igura T, Imanaka K, Yamada A, Oshita M, Hagiwara H, Mita E, Ito T, Inui Y, Hijioka T, Yoshihara H, Inoue A, Imai Y, Kato M, Kiso S, Kanto T, Takehara T, Kasahara A, Hayashi N. · Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka, Japan. · Hepatol Res. · Pubmed #19207583 No free full text.

Abstract: Aim: The objective of this study was to elucidate the long-term effects of interferon (IFN)alpha-2b plus ribavirin combination therapy and to clarify whether this therapy can reduce the incidence of hepatocellular carcinoma (HCC) in patients with chronic hepatitis C. Methods: A total of 403 patients infected with hepatitis C virus (HCV) were enrolled in a multicenter trial. All patients were treated with a combination of IFN-alpha-2b plus ribavirin therapy. We examined the incidence of HCC after combination therapy and analyzed the risk factors for liver carcinogenesis. Results: A sustained virological response (SVR) was achieved by 139 (34%) of the patients. The cumulative rate of incidence of HCC was significantly lower in SVR patients than in non-SVR patients (P = 0.03), while there was no difference in the cumulative incidence of HCC between the transient response (TR) group and the no response (NR) group. Cox's regression analysis indicated the following risk factors as independently significant in relation to the development of HCC: age being > 60 years (P = 0.006), advanced histological staging (P = 0.033), non-SVR to IFN therapy (P = 0.044). The cumulative incidence rate of HCC was significantly lower in patients who had average serum alanine aminotransferase (ALT) levels of < 40 IU/L than in those who showed average serum ALT levels of >== 40 IU/L after the combination therapy (P = 0.021). Conclusions: These results suggest that the attainment of SVR or continuous normalization of ALT levels after IFN therapy can affect patients apart from HCC development.

Miyazaki M, Kanto T, Inoue M, Itose I, Miyatake H, Sakakibara M, Yakushijin T, Kakita N, Hiramatsu N, Takehara T, Kasahara A, Hayashi N. · Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka, Japan. · J Med Virol. · Pubmed #18428149 No free full text.

Abstract: Dendritic cells utilize various sets of Toll-like receptors (TLR) or cytosolic sensors to detect pathogens and evoke immune responses. In patients with hepatitis C virus (HCV) infection, a higher prevalence of various infectious diseases is reported; suggesting that innate immunity against pathogens is impaired. The aim of this study was to clarify whether the TLR and retinoic acid inducible gene-I (RIG-I) system in myeloid dendritic cells is preserved or not in chronic HCV infection. The expression of TLRs, RIG-I and its relatives were compared in myeloid dendritic cells between 39 patients and 52 healthy volunteers. The induction of type-I interferon (IFN) and inflammatory cytokines was examined in response to agonists for TLR2 (palmitoyl-3-cysteine-serine-lysine-4), TLR3/RIG-I (polyinosine-polycytidylic acid) or TLR4 (lipopolysaccharide). The relative expressions of TLR2, TLR4, RIG-I, and LGP2 from the patients were significantly higher than those from the volunteers, whereas TLR3 and MDA-5 expressions did not differ. In search for factors regulating TLR/RIG-I expression, it was shown that IFN-alpha, polyinosine-polycytidylic acid and lipopolysaccharide induced TLR3, TLR4 and RIG-I, but TNF-alpha, HCV core or HCV non-structural proteins did not. For the functional analyses, myeloid dendritic cells from the patients induced significantly less amounts of IFN-beta, TNF-alpha and IL-12p70 in response to polyinosine-polycytidylic acid or lipopolysaccharide. It is noteworthy that the expression of TRIF and TRAF6, which are essential adaptor molecules transmitting TLR3 or TLR4-dependent signals, is reduced in the patients. Thus, innate cytokine responses in myeloid dendritic cells are impaired regardless of enhanced expressions of TLR2, TLR4, and RIG-I in HCV infection.

Kanada A, Takehara T, Ohkawa K, Kato M, Tatsumi T, Miyagi T, Sakamori R, Yamaguchi S, Uemura A, Kohga K, Sasakawa A, Hikita H, Kawamura K, Kanto T, Hiramatsu N, Hayashi N. · Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Yamadaoka, Suita, Osaka, Japan. · Hepatol Res. · Pubmed #18070052 No free full text.

Abstract: The efficacy of entecavir for patients with hepatitis B virus/human immunodeficiency virus coinfection has not been fully elucidated. Here we examined a patient coinfected with both viruses in whom entecavir-resistant hepatitis B virus appeared. The 60-year-old Japanese male with the coinfection received antiretroviral therapy including lamivudine. The therapy initially suppressed replication of both viruses, followed by reactivation of the hepatitis B virus alone by 2 years of therapy. He subsequently received entecavir therapy in addition to the antiretroviral regimen. After entecavir administration, the hepatitis B virus DNA level was slightly reduced, but then increased after 6 months of entecavir therapy. In the sequencing analysis of hepatitis B virus, no drug resistance-associated amino acid substitutions were observed in the reverse transcriptase (rt) domain before antiretroviral therapy. The lamivudine-resistant amino acid substitutions at rt173, rt180 and rt204 were detected before entecavir administration, and further the entecavir-resistant rt202 substitution was observed after 6 months of entecavir therapy. The full-length hepatitis B sequences showed that the viral strain derived from the patient belonged to genotype H. In summary, this report describes a patient with hepatitis B virus/human immunodeficiency virus coinfection who received entecavir therapy in addition to an antiretroviral regimen and showed the early emergence of entecavir-resistance hepatitis B virus. In entecavir therapy for patients infected with both viruses, great care should be taken with respect to the emergence of entecavir-resistant hepatitis B virus, especially in patients with pre-existing lamivudine-resistant virus.

Kurashige N, Hiramatsu N, Ohkawa K, Oze T, Inoue Y, Kurokawa M, Yakushijin T, Igura T, Kiso S, Kanto T, Takehara T, Tamura S, Kasahara A, Oshita M, Hijioka T, Katayama K, Yoshihara H, Hayashi E, Imai Y, Kato M, Hayashi N. · Osaka University, Osaka, Japan. · Hepatol Res. · Pubmed #18034827 No free full text.

Abstract: Aim: Lamivudine (LAM) has been widely used to treat chronic hepatitis B (CHB) patients, but the emergence of a LAM-resistant virus greatly limits its therapeutic efficacy. In this study, we tried to identify factors affecting the emergence of a LAM-resistant virus in CHB patients treated with LAM. Methods: The subjects were 190 CHB patients in continuous LAM therapy (139 males, mean age 50 years, 87 HBeAg-positive). The mean duration of follow-up was 39 months (range 12-104). The initial viral response (IVR) was defined as HBV DNA < 4.0 logcopies/mL, and the initial biochemical response (IBR) as normalization of alanine aminotransferase (ALT) (<40 IU/L) at 6 months. Results: IVR was positive in 86% of the patients. The cumulative emergence rates of LAM-resistant virus were 10% at 1 year, 30% at 2 years and 46% at 3 years. In univariate analysis, factors contributing to the emergence of LAM-resistant virus were baseline HBV DNA > 6.5 logcopies/mL (P = 0.0044), HBeAg-positivity (P = 0.0062), IBR (P = 0.01) and IVR (P < 0.0001). The cumulative emergence rates of LAM-resistant virus in IVR-positive and -negative patients were 4% and 41% at 1 year, and 41% and 79% at 3 years. In multivariate analysis, only IVR was an independent factor affecting the emergence of LAM-resistant virus (P < 0.0001). Conclusion: IVR is a useful factor for predicting the emergence of LAM-resistant virus in CHB patients treated with LAM. For IVR-negative patients, therapeutic options other than LAM monotherapy should be used because of the high incidence of the emergence of LAM-resistant virus.

Kanada A, Takehara T, Ohkawa K, Tatsumi T, Sakamori R, Yamaguchi S, Uemura A, Kohga K, Sasakawa A, Hikita H, Hijioka T, Katayama K, Deguchi M, Kagita M, Kanto T, Hiramatsu N, Hayashi N. · Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita, Japan. · Intervirology. · Pubmed #17975320 No free full text.

Abstract: OBJECTIVE: Genome-wide sequences of hepatitis B virus strain associated with type B fulminant hepatitis have not been compared with those of acute self-limited hepatitis. We carried out full-length sequencing analysis of viral strains derived from patients with type B acute liver injury. METHODS: Nine acute self-limited hepatitis and 6 fulminant hepatitis patients were the subjects of this study. Full-length sequencing analysis of viral DNA was done by PCR-direct sequencing. RESULTS: Higher frequencies in fulminant hepatitis strains compared with acute hepatitis ones were observed in the T1762/A1764 (p < 0.05), A1896 (p = 0.09) and M1753 (M = C or A) (p = 0.09) mutations. Viruses related to fulminant hepatitis possessed the higher number of nucleotide substitutions than those related to acute hepatitis in the whole virus genome (p < 0.01) and various regions including preS/S gene (p < 0.05), precore/core gene (p < 0.01), polymerase gene (p < 0.05) and basic core promoter/core upstream regulatory sequence (p < 0.01). The high number of nucleotide substitutions in viruses related to fulminant hepatitis was predominantly non-synonymous in the preS/S and precore/core genes. CONCLUSION: Development of type B fulminant hepatitis may be associated with a highly mutated hepatitis B virus strain.

Kanto T, Hayashi N. · Department of Gastroenterology and Hepatology and Department of Dendritic Cell Biology and Clinical Applications, Osaka University Graduate School of Medicine, Osaka, Japan. · Hepatol Res. · Pubmed #17931181 No free full text.

Abstract: Sequential activation of innate and adaptive immune response is crucial for virus elimination. We thus sought to clarify the role of innate immune system in the pathogenesis of hepatitis C virus (HCV) infection. Dendritic cells (DC) sense virus infection via toll-like receptors (TLR) or retinoic acid inducible gene-I (RIG-I), resulting in the secretion of type-I interferons (IFN) and inflammatory cytokines. Blood DC consist of two subsets; myeloid DC (MDC) and plasmacytoid DC (PDC). In MDC from HCV-infected patients, regardless of higher expression of TLR2, TLR4 and RIG-I compared to the controls, the levels of TLR/RIG-I-mediated IFN-beta or TNF-alpha induction are lower than those in uninfected donors. These results suggest that the signal transduction in the downstream of TLR/RIG-I in MDC is profoundly impaired in HCV infection. In response to IFN-alpha, DC are able to express MHC class-I related chain A/B (MICA/B) and activate natural killer (NK) cells following ligation of NKG2D. Interestingly, DC from HCV-infected patients are unresponsive to exogenous IFN-alpha to enhance MICA/B expression and fail to activate NK cells. Alternatively, NK cells from HCV-infected patients downregulate DC functions in the presence of human leukocyte antigen E-expressing hepatocytes by secreting interleukin (IL)-10 and transforming growth factor-beta1. Such functional alteration of NK cells in HCV infection is ascribed to the enhanced expression of inhibitory receptor NKG2A/CD94 compared to the healthy counterparts. Invariant NKT cells activated by CD1d-positive DC secrete both T-helper (Th)1 and Th2 cytokines, serving as immune regulators. The frequency of NKT cells in chronic HCV infection does not differ from those in healthy donors. Activated NKT cells produce higher levels of IL-13 but comparable levels of IFN-gamma with those from healthy subjects, showing that NKT cells are biased to Th2-type in chronic HCV infection. In conclusion, cross-talks among DC, NK cells and NKT cells are critical in shaping subsequent adaptive immune response against HCV.

Abe T, Kaname Y, Hamamoto I, Tsuda Y, Wen X, Taguwa S, Moriishi K, Takeuchi O, Kawai T, Kanto T, Hayashi N, Akira S, Matsuura Y. · Department of Molecular Virology, Graduate School of Medicine, Osaka University, Osaka, Japan. · J Virol. · Pubmed #17567694 links to  free full text

Abstract: Hepatitis C virus (HCV) infection induces a wide range of chronic liver injuries; however, the mechanism through which HCV evades the immune surveillance system remains obscure. Blood dendritic cells (DCs) play a pivotal role in the recognition of viral infection and the induction of innate and adaptive immune responses. Several reports suggest that HCV infection induces the dysfunction of DCs in patients with chronic hepatitis C. Toll-like receptor (TLR) has been shown to play various roles in many viral infections; however, the involvement of HCV proteins in the TLR signaling pathway has not yet been precisely elucidated. In this study, we established mouse macrophage cell lines stably expressing HCV proteins and determined the effect of HCV proteins on the TLR signaling pathways. Immune cells expressing NS3, NS3/4A, NS4B, or NS5A were found to inhibit the activation of the TLR2, TLR4, TLR7, and TLR9 signaling pathways. Various genotypes of NS5A bound to MyD88, a major adaptor molecule in TLR, inhibited the recruitment of interleukin-1 receptor-associated kinase 1 to MyD88, and impaired cytokine production in response to TLR ligands. Amino acid residues 240 to 280, previously identified as the interferon sensitivity-determining region (ISDR) in NS5A, interacted with the death domain of MyD88, and the expression of a mutant NS5A lacking the ISDR partially restored cytokine production. These results suggest that the expression of HCV proteins modulates the TLR signaling pathway in immune cells.

Tani H, Komoda Y, Matsuo E, Suzuki K, Hamamoto I, Yamashita T, Moriishi K, Fujiyama K, Kanto T, Hayashi N, Owsianka A, Patel AH, Whitt MA, Matsuura Y. · Department of Molecular Virology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan. · J Virol. · Pubmed #17553880 links to  free full text

Abstract: Although in vitro replication of the hepatitis C virus (HCV) JFH1 clone of genotype 2a (HCVcc) has been developed, a robust cell culture system for the 1a and 1b genotypes, which are the most prevalent viruses in the world and resistant to interferon therapy, has not yet been established. As a surrogate virus system, pseudotype viruses transiently bearing HCV envelope proteins based on the vesicular stomatitis virus (VSV) and retrovirus have been developed. Here, we have developed a replication-competent recombinant VSV with a genome encoding unmodified HCV E1 and E2 proteins in place of the VSV envelope protein (HCVrv) in human cell lines. HCVrv and a pseudotype VSV bearing the unmodified HCV envelope proteins (HCVpv) generated in 293T or Huh7 cells exhibited high infectivity in Huh7 cells. Generation of infectious HCVrv was limited in some cell lines examined. Furthermore, HCVrv but not HCVpv was able to propagate and form foci in Huh7 cells. The infection of Huh7 cells with HCVpv and HCVrv was neutralized by anti-hCD81 and anti-E2 antibodies and by sera from chronic HCV patients. The infectivity of HCVrv was inhibited by an endoplasmic reticulum alpha-glucosidase inhibitor, N-(n-nonyl) deoxynojirimycin (Nn-DNJ), but not by a Golgi mannosidase inhibitor, deoxymannojirimycin. Focus formation of HCVrv in Huh7 cells was impaired by Nn-DNJ treatment. These results indicate that the HCVrv developed in this study can be used to study HCV envelope proteins with respect to not only the biological functions in the entry process but also their maturation step.

Miyatake H, Kanto T, Inoue M, Sakakibara M, Kaimori A, Yakushijin T, Itose I, Miyazaki M, Kuzushita N, Hiramatsu N, Takehara T, Kasahara A, Hayashi N. · Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita-shi, Osaka, Japan. · J Viral Hepat. · Pubmed #17501761 No free full text.

Abstract: In interferon-alpha (IFN-alpha)/ribavirin combination therapy for chronic hepatitis C (CHC), an enhanced T helper 1 (Th1) response is essential for the eradication of hepatitis C virus (HCV). We aimed to elucidate the role of IFN-alpha or IFN-alpha/ribavirin in dendritic cell (DC) ability to induce Th1 response in HCV infection. We generated monocyte-derived DC from 20 CHC patients and 15 normal subjects driven by granulocyte-macrophage colony-stimulating factor and interleukin 4 (IL-4) without IFN-alpha (GM/4-DC), with IFN-alpha (IFN-DC), with ribavirin (R-DC) or with IFN-alpha/ribavirin (IFN/R-DC) and compared their phenotypes and functions between the groups. We also compared them in 14 CHC patients between who subsequently attained sustained virological response (SVR) and who did not (non-SVR) by 24 weeks of IFN-alpha/ribavirin therapy. Compared with GM/4-DC, IFN-DC displayed higher CD86 expression, but lesser ability to secrete IL-10 and were more potent to prime CD4(+) T cells to secrete IFN-gamma and IL-2. Such differences were more significant in healthy subjects than in CHC patients. No additive effect of ribavirin was observed in DC phenotypes and functions in vitro either which was used alone or in combined with IFN-alpha. However, in the SVR patients, an ability of IFN/R-DC to prime T cells to secrete IFN-gamma and IL-2 was higher than those of IFN-DC and those of IFN/R-DC in the non-SVR group, respectively. In conclusion, DC from CHC patients are impaired in the ability to drive Th1 in response to IFN-alpha. Such DC impairment is restored in vitro by the addition of ribavirin in not all but some patients who cleared HCV by the combination therapy.

Oze T, Hiramatsu N, Kurashige N, Tsuda N, Yakushijin T, Kanto T, Takehara T, Kasahara A, Kato M, Yoshihara H, Katayama K, Kubota S, Hijioka T, Ishibashi K, Oshita M, Hagiwara H, Haruna Y, Mita E, Tamura S, Hayashi N. · Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita 565-0871, Japan. · J Gastroenterol. · Pubmed #17048050 No free full text.

Abstract: BACKGROUND: The aim of this study was to examine the factors correlated with the progression of ribavirin-induced hemolytic anemia in patients with chronic hepatitis C treated by interferon and ribavirin combination therapy. METHODS: This study was conducted on 505 patients by the Osaka Liver Disease Study Group. A decline of hemoglobin (Hb) concentration by 2 g/dl at the end of 2 weeks from the start of the treatment ("2 by 2" standard) was adopted as a predictive factor for progression to severe anemia. The ribavirin apparent clearance (CL/F) was also examined. RESULTS: Of 482 patients whose Hb value was more than 12 g/dl before the treatment, 68 patients (14%) had to discontinue ribavirin owing to severe anemia. Patients in the "2 by 2"-positive group (Hb decline over 2 g/dl) and the group with lower CL/F were significantly more likely to discontinue ribavirin owing to severe anemia. Discontinuation was more common among patients aged 60 years or older than for those under 60 years old (21% vs. 9%, P < 0.001). Among patients aged 60 years or older, only the "2 by 2" standard was significantly associated with the discontinuance of ribavirin owing to severe anemia in a multivariate analysis (odds ratio, 4.18; P < 0.001). CONCLUSIONS: The "2 by 2" standard of Hb decline can be used to identify patients likely to develop severe anemia. The early reduction of ribavirin can help prevent progression to severe anemia, thus allowing ribavirin therapy to be completed even in older patients.

Hosui A, Takehara T, Ohkawa K, Kanazawa Y, Tatsumi T, Yamaguchi S, Sakamori R, Hiramatsu N, Kanto T, Hayashi N. · Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan. · Biochem Biophys Res Commun. · Pubmed #16806084 No free full text.

Abstract: The influence of hepatitis C virus (HCV) protein(s) on cellular differentiation remains to be clarified. Using murine normal liver epithelial cells, we investigated whether HCV core protein affects differentiation into hepatocytes. Mock and HCV core-expressing cells were stimulated with oncostatin M (OSM) and dexamethasone, and the degree of differentiation was evaluated by measuring the expression of albumin and tyrosine aminotransferase (TAT). Lower amounts after stimulation were found in HCV core-expressing cells than in mock cells. Phosphorylation of the signal transducer and activator transcription factor 3 (STAT3) was prevented by the HCV core under OSM stimulation. Reporter gene assay revealed that the HCV core/Janus kinase (JAK) interaction directly suppressed the OSM-dependent JAK-STAT signal transduction. Furthermore, expression of OSM receptor beta (OSMRbeta) after stimulation was prevented by the HCV core. In conclusion, the HCV core may suppress differentiation into hepatocytes via inhibition of the JAK-STAT pathway and OSMRbeta expression.

Hiramatsu N, Oze T, Tsuda N, Kurashige N, Koga K, Toyama T, Yasumaru M, Kanto T, Takehara T, Kasahara A, Kato M, Yoshihara H, Katayama K, Hijioka T, Hagiwara H, Kubota S, Oshita M, Haruna Y, Mita E, Suzuki K, Ishibashi K, Hayashi N. · Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita City, Osaka 565-0871, Japan. · Hepatol Res. · Pubmed #16678478 No free full text.

Abstract: The aim of this study was to investigate the efficacy and safety of combination therapy of interferon and ribavirin for aged patients with chronic hepatitis C. METHODS: This study was conducted at Osaka University Hospital and institutions participating in the Osaka Liver Disease Study Group on 329 patients with chronic hepatitis C receiving interferon and ribavirin combination therapy (group A, under 60 year old, n=199; group B, 60-64 year old, n=64; group C, over 65 year old (mean age, 67.8+/-2.2 year old, n=66)). Of the 293 patients who were tested for HCV serotype and HCV viral loads, 215 had HCV-RNA with serotype 1 and high viral loads (1H) and the other 78 had HCV-RNA with serotype 2 or low viral loads (non-1H). RESULTS: In per-protocol analysis, the overall SVR rate of 1H patients was 28% (51/184). Among the 1H patients, the SVR rate was significantly lower in group C (16%) and group B (17%) than in group A (34%) (p<0.05). The overall SVR rate of non-1H patients was 85% (57/67). No significant difference was found in the SVR rate among group C (79%), group B (100%), and group A (84%). On the other hand, the discontinuance of both drugs due to side effects was 29% (19/66) in group C, 20% (13/64) in group B, and 11% (21/199) in group A, with the discontinuance rates being higher in the older group (p=0.002). CONCLUSIONS: In aged chronic hepatitis C patients, interferon and ribavirin combination therapy can be recommended for the non-1H patients who showed a high SVR rate of approximately 65%, but not for the 1H patients.

Inoue M, Kanto T, Miyatake H, Itose I, Miyazaki M, Yakushijin T, Sakakibara M, Kuzushita N, Hiramatsu N, Takehara T, Kasahara A, Hayashi N. · Department of Dendritic Cell Biology and Clinical Application, Osaka University Graduate School of Medicine, Osaka, Japan. · J Hepatol. · Pubmed #16580086 No free full text.

Abstract: BACKGROUND/AIMS: Human invariant natural killer T (iNKT) cells express a TCR Valpha24-JalphaQ paired with Vbeta11 and are activated by a surrogate ligand, alpha-galactosylceramide (alphaGalCer). The iNKT cells are involved in the regulation of anti-viral immune responses; however, little is known about their roles in hepatitis C virus (HCV) infection. METHODS: We compared the frequency of peripheral iNKT cells and their cytokine producing capacity reactive to alphaGalCer between chronically HCV-infected patients and healthy subjects. Cytokine production of freshly isolated iNKT cells were analyzed by ELISPOT. Activated iNKT cells were obtained by culture with alphaGalCer-loaded dendritic cells (DCs) and re-stimulated with them for the measurement of cytokine production. RESULTS: The frequencies of iNKT cells were not different between HCV-infected patients and healthy subjects. The number of fresh IFN-gamma-producing iNKT cells reactive to alphaGalCer was not different between the patients and controls, whereas fresh iNKT cells produced negligible amounts of Th2 cytokines regardless of HCV infection. In response to alphaGalCer, expanded iNKT cells from the patients secreted IFN-gamma comparable in amount to controls, whereas they released significantly more IL-13 than cells from controls. CONCLUSIONS: Activated iNKT cells from HCV-infected patients gain more ability to secrete IL-13 than those from healthy subjects.

Yakushijin T, Kanto T, Inoue M, Oze T, Miyazaki M, Itose I, Miyatake H, Sakakibara M, Kuzushita N, Hiramatsu N, Takehara T, Kasahara A, Hayashi N. · Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan. · Hepatol Res. · Pubmed #16458588 No free full text.

Abstract: BACKGROUND: Dendritic cells (DCs) utilize Toll-like receptors (TLRs) to sense virus and initiate immune responses. We aimed at elucidating the roles of TLRs on DCs in hepatitis C virus (HCV) infection. METHODS: Monocyte-derived DCs were obtained from 32 healthy volunteers (HV) and 30 chronically HCV-infected patients (CH). TLR2, TLR3 and TLR4 expressions on immature DCs were quantified by real-time quantitative RT-PCR. We stimulated DCs with specific TLR ligands and examined DC maturation, cytokine production and ability to stimulate allogeneic CD4(+) T cells. RESULTS: TLR2 expression on immature DCs was lower in the CH group, whereas those of TLR3 or TLR4 were not different between the groups. Each TLR ligand induced DC maturation and stimulated them to release comparable levels of IL-12p70, IL-6, IL-10, TNF-alpha and IFN-beta between the groups. TLR2 and TLR4 ligands enhanced DC ability to stimulate T cell proliferation, with the degree due to the TLR2 ligand being lower in the CH group. CONCLUSIONS: In HCV infection, the TLR2 expression on DCs is reduced and TLR2-stimulated DCs show lesser ability to proliferate T cells than healthy counterparts, suggesting that the TLR2 system is involved in HCV-induced immunopathogenesis.

Kanto T, Inoue M, Miyazaki M, Itose I, Miyatake H, Sakakibara M, Yakushijin T, Kaimori A, Oki C, Hiramatsu N, Kasahara A, Hayashi N. · Department of Molecular Therapeutics, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan. · Intervirology. · Pubmed #16166790 No free full text.

Abstract: Hepatitis C virus (HCV) induces chronic liver disease in hosts which can eventually progresses to liver cirrhosis and hepatocellular carcinoma. However, progression of liver disease is slower in patients with persistently normal levels of alanine aminotransferase (ALT) than in those with active hepatitis. Although distinct immune responses against HCV have been proposed in asymptomatic infection, the role of circulating dendritic cells (DC) in the pathogenesis of these patients remains obscure. To address this issue, we compared the number and function of myeloid DC (MDC) and plasmacytoid DC (PDC) between uninfected individuals and HCV-infected patients with or without elevated ALT levels. Numbers of DC and DC progenitors were significantly lower in patients with chronic active hepatitis than in control subjects. However, no differences were found in the number of DC between normal controls and HCV-infected patients with persistently normal ALT levels. MDC from patients with active hepatitis were less able to polarize naive CD4 T cells into the Th1 phenotype, while their MDC and PDC primed more CD4 T cells producing IL-10 than those from normal controls. Such dysfunction of DC was also observed in patients with persistently normal ALT levels. In conclusion, circulating DC decrease in number predominantly in HCV-infected patients with active hepatitis, and the function of DC is impaired even in those with normal ALT levels.

Kanto T, Inoue M, Miyatake H, Sato A, Sakakibara M, Yakushijin T, Oki C, Itose I, Hiramatsu N, Takehara T, Kasahara A, Hayashi N. · Department of Molecular Therapeutics, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan. · J Infect Dis. · Pubmed #15529255 No free full text.

Abstract: Hepatitis C virus (HCV) infection induces a wide range of chronic liver injuries. The mechanism by which HCV evades the immune surveillance system remains obscure. Blood dendritic cells (DCs) consist of myeloid and plasmacytoid subsets that play distinct roles in the regulation of antivirus immune responses; however, their roles in the pathogenesis of HCV infection are yet to be determined. We compared the numbers and functions of myeloid and plasmacytoid DCs between 43 patients with chronic hepatitis and 26 age-matched healthy volunteers. Absolute numbers of myeloid DCs, plasmacytoid DCs, and DC progenitors in the periphery were significantly lower in patients with chronic hepatitis than in healthy volunteers. Myeloid and plasmacytoid DCs from the patients had impaired abilities to stimulate allogeneic CD4 T cells and to produce interleukin (IL)-12 p70 and interferon- alpha , compared with those from healthy volunteers. After exposure to naive CD4 T cells, myeloid DCs from the patients were less able to drive the T helper type 1 response, whereas myeloid and plasmacytoid DCs from the patients primed more IL-10-producing cells than did those from healthy volunteers. In conclusion, in chronic HCV infection, both types of blood DCs are reduced and have an impaired ability to polarize T helper cells.

Jinushi M, Takehara T, Tatsumi T, Kanto T, Miyagi T, Suzuki T, Kanazawa Y, Hiramatsu N, Hayashi N. · Department of Molecular Therapeutics, Osaka University Graduate School of Medicine, Yamadaoka 2-2, Suita, Osaka 565-0871, Japan. · J Immunol. · Pubmed #15528343 links to  free full text

Abstract: NK cells are potent activators of dendritic cells (DCs), but it remains obscure how third-party cells affect the ability of NK cells to modulate DC functions. We show here that NK cells derived from healthy donors (N-NK), when cocultured with human liver epithelial cells, induced maturation as well as activation of DCs, such as increased migratory capacity as well as T cell stimulatory activity. In contrast, NK cells from chronic hepatitis C virus-infected donors (HCV-NK) were not capable of activating DCs under the same conditions. In comparison to N-NK, HCV-NK showed higher expression of CD94/NKG2A and produced IL-10 and TGFbeta when cultured with hepatic cells, most of which express HLA-E, a ligand for CD94/NKG2A. Blockade of NKG2A restored the ability of HCV-NK to activate DCs, which appeared to result from the reduced NK cell production of IL-10 and TGFbeta. The blockade also endowed HCV-NK with an ability to drive DCs to generate Th1-polarized CD4+ T cells. These findings show that NK cell modulation of DCs is regulated by third-party cells through NK receptor and its ligand interaction. Aberrant expression of NK receptors may have an impact on the magnitude and direction of DC activation of T cells under pathological conditions, such as chronic viral infection.