Norio Horiike

Dendritic cells with immature phenotype and defective function in the peripheral blood from patients with hepatocellular carcinoma

BACKGROUND/AIMS Defects and dysfunctions in antigen-presenting dendritic cells have been shown during carcinogenesis. The phenotype and function of dendritic cells have been studied in patients with hepatocellular carcinoma to explore the possibility of dendritic cell-based immune therapy in hepatocellular carcinoma. METHODS The stimulatory capacity of dendritic cells in allogenic mixed leukocytes reaction, the expression of surface makers on dendritic cells, the production of cytokines and nitric oxide by dendritic cells and the levels of maturation of dendritic cells from 17 patients with hepatocellular carcinoma, 10 patients with liver cirrhosis and 10 normal controls were compared. RESULT Dendritic cells from hepatocellular carcinoma had significantly lower capacity to stimulate allogenic T cells in allogenic mixed leukocytes reaction compared with dendritic cells from liver cirrhosis and normal controls (p<0.05). Dendritic cells from hepatocellular carcinoma expressed significantly lower levels of HLA DR and induced decreased amounts of interleukin-12 compared with dendritic cells from normal controls (p<0.05). On the other hand, dendritic cells from hepatocellular carcinoma produced significantly higher levels of nitric oxide and tumor necrosis factor-a compared with dendritic cells from liver cirrhosis and normal controls (p<0.05). The uptake of fluorescein isothiocyanate-labeled dextran revealed an immature phenotype of dendritic cells from hepatocellular carcinoma compared with dendritic cells from liver cirrhosis (p<0.05). CONCLUSION The results of this study on the function of dendritic cells in hepatocellular carcinoma, and the prevalence of immature dendritic cells in hepatocellular carcinoma in the microenvironment of high levels of inflammatory cytokines indicate a specific defect of dendritic cell maturation during hepatocarcinogenesis. These data show that induction of dendritic cell maturation might be an approach to dendritic cell-based immune therapy during hepatocellular carcinoma.

Detection of Hepatitis C Virus (HCV) in Serum and Peripheral-Blood Mononuclear Cells from HCV-Monoinfected and HIV/HCV–Coinfected Persons

It has been speculated that hepatitis C virus (HCV) replicates in peripheral-blood mononuclear cells (PBMCs), which, therefore, may be a site for interaction with human immunodeficiency virus (HIV). We used strand-specific real-time polymerase chain reaction to detect HCV RNA in 28 HCV-monoinfected and 20 HIV/HCV-coinfected women. At the first visit, positive-strand HCV RNA was detected in serum samples from 89% of the women, whereas positive-strand HCV RNA was detected in PBMC samples from 32% and 55% of the HCV-monoinfected and HIV/HCV-coinfected women, respectively. After initiation of antiretroviral therapy, the HIV/HCV-coinfected women were significantly more likely to have detectable positive- and negative-strand HCV RNA in the PBMC compartment than were the HCV-monoinfected women. HIV and HCV RNA levels were not correlated. Serum HCV RNA levels were correlated over time; HCV RNA levels in the serum and PBMC compartments were not. These data suggest differential regulation of HCV RNA in the serum and PBMC compartments and may partially explain the limited HCV antiviral response rates observed in coinfected persons.

Soluble CD163 in patients with liver diseases: very high levels of soluble CD163 in patients with fulminant hepatic failure

BackgroundThe levels of several cytokines and chemokines are elevated in various liver diseases, especially in fulminant hepatic failure (FHF). Activated macrophages may have a role in the production of these immune modulators. CD163 is a member of a scavenger receptor family and is expressed mainly on activated macrophages, and a soluble form of CD163 (sCD163) is released from activated macrophages. The aim of this study was to assess sCD163 levels in patients with FHF and to evaluate their clinical significance.MethodsThe levels of sCD163 in the sera were measured in 21 patients with FHF, 17 patients with acute hepatitis (AH), 22 patients with chronic hepatitis (CH), and 14 normal healthy controls (NC), by an enzyme-linked immunosorbent assay. The levels of sCD163 were observed serially in patients with FHF and AH.ResultsThe levels of sCD163 in the sera from patients with FHF were significantly higher than those in patients with AH and CH and the NC group (P < 0.0001). There was a good correlation between serum levels of sCD163 and prothrombin time (r = −0.677; P < 0.0001). A kinetic study revealed that the levels of sCD163 decreased in patients with AH and in survivors of FHF, whereas the levels of sCD163 progressively increased in nonsurvivors of FHF.ConclusionsThis study shows that the products of activated macrophages may be involved in the pathogenesis of FHF. This study also inspires optimism that sCD163 may possess prognostic importance in FHF.

Macrophage migration inhibitory factor activates antigen‐presenting dendritic cells and induces inflammatory cytokines in ulcerative colitis

The level of macrophage migration inhibitory factor (MIF) and the functions of dendritic cells (DC) are up‐regulated in the peripheral blood, and the numbers of MIF‐expressing cells and mature DC are increased at the colonic mucosa from patients with ulcerative colitis (UC). However, a functional relationship between MIF and DC, and the role of MIF in the pathogenesis of UC, are not clear. In this study, we showed that a pure population of peripheral blood DC is a new and still unknown source of MIF. DC from UC patients produced significantly higher levels of MIF (17·5 ± 9·8 ng/ml, n = 10) compared with patients with Crohn’s disease (CD) (4·6 ± 2·5 ng/ml, n = 5, P < 0·01) and control subjects (5·0 ± 2·6 ng/ml, n = 10, P < 0·01). A double immunofluorescence study revealed the expression of MIF by CD83‐positive mature DC at the colonic mucosa from UC patients. Blood DC treated with high amounts of MIF (500 ng/ml) showed a significantly higher stimulatory capacity (43287 ± 5998 CPM, n = 5) in an allogenic mixed leucocyte reaction compared with untreated DC (27528 ± 8823 CPM, n = 5, P < 0·05). Study of intracellular cytokine expression showed that MIF induced significant levels of interleukin (IL)‐1β and IL‐8 in monocytes and DC from UC and CD patients. These results showing the capacity of MIF to induce increased functional capacity of DC, and to produce IL‐1β and IL‐8 from monocytes and DC, indicate a role of MIF in the induction and/or perpetuation of the inflammatory environment in UC.

Absence of CD83-positive mature and activated dendritic cells at cancer nodules from patients with hepatocellular carcinoma: relevance to hepatocarcinogenesis

Mature and activated dendritic cells (CD83-positive DCs) are essential for the recruitment and survival of activated tumor-specific lymphocytes during carcinogenesis. The frequencies of CD83 positive DCs were almost same in peripheral blood from patients with hepatocellular carcinoma (HCC) and cirrhosis of liver (LC). However, the numbers of CD83 positive DCs in liver tissues were significant lower in HCC compared with LC (6.6+/-10.9 vs. 33.3+/-24 DCs/specimen, P<0.05). Most importantly, there were no CD83-positive DCs at cancer nodules in HCC. A role of infiltration of activated DCs in liver during hepatocarcinogenesis is shown.

Virtual Sonographic Radiofrequency Ablation of Hepatocellular Carcinoma Visualized on CT but Not on Conventional Sonography

OBJECTIVE Some nodules cannot be visualized clearly on conventional sonography but can be visualized on CT. In the present study, we evaluated the usefulness of real-time percutaneous ablation therapy under virtual sonographic guidance for these nodules. SUBJECTS AND METHODS In vitro experiments were performed with gelatin gel to evaluate the accuracy of virtual sonography. We also studied 50 patients with 58 hepatocellular carcinoma nodules, of whom 18 patients (21 nodules) underwent radiofrequency ablation by virtual sonography. This was the initial treatment for seven of these patients and an additional treatment for 11 patients. Thirty-two patients (37 nodules) received radiofrequency ablation without virtual imaging. The patients receiving standard radiofrequency ablation were retrospectively selected as the historical control group under the same conditions as the study group. RESULTS The in vitro gelatin gel study revealed that all punctures had been performed accurately. In both the initial-treatment group and the additional-treatment group, the mean number of treatments with virtual sonography was significantly lower than that without virtual sonography (p = 0.003 for both groups). The rates of local recurrence and complications did not differ significantly between the two groups. CONCLUSION In the treatment of nodules not depicted on sonography, radiofrequency ablation assisted by virtual sonography is an efficacious alternative.

Decreased interferon‐α production and impaired T helper 1 polarization by dendritic cells from patients with chronic hepatitis C

Patients with chronic hepatitis C (CHC) are unable to prime and maintain vigorous T cell responses that are initiated during the acute phase of hepatitis C virus (HCV) infection. As dendritic cells (DCs) induce and regulate both innate and adaptive immune responses, the aim of this study was to analyse two critical functions of DCs: firstly, production of interferon (IFN)‐α and, secondly, polarization of T helper 1 lymphocytes. The frequencies of plasmacytoid DC (PDC) and myeloid DC (MDC) were estimated in 63 patients with CHC and 34 normal controls using four‐colour flow cytometry. Circulating DCs were isolated from peripheral blood of CHC patients (n = 10) and normal controls (n = 10). These DCs were cultured with herpes simplex virus‐1 to evaluate their capacity to produce IFN‐α. The capacity of DCs to induce polarization of autologous naive CD4+ T lymphocytes to IFN‐γ‐producing effector T lymphocytes was also assessed. The frequencies of PDCs producing intracellular IFN‐α (P < 0·01) and the levels of IFN‐α in culture supernatant of PDCs (P < 0·01) were significantly lower in patients with CHC compared to those of normal controls. The numbers of MDC were significantly lower in patients with CHC (8·2 (6·0)/µl, median (interquartile range), n = 63) compared to normal control (11·7 (7·8)/µl, n = 34) (P < 0·01). Moreover, DCs from patients with CHC induced significantly lower numbers of IFN‐γ‐producing effector T lymphocytes compared to that of controls (P < 0·01). This study indicates that the low IFN‐α‐producing capacity and impaired T helper 1 polarization ability of DCs from patients with CHC might be responsible for the typical low anti‐HCV immune responses in these patients.

Drug-induced liver injury in Japan: An analysis of 1676 cases between 1997 and 2006

At the 44th Annual Meeting of the Japan Society of Hepatology, 1674 cases of drug‐induced liver injury (DILI), occurring between January 1997 and December 2006, were reviewed. Data were obtained by questionnaires completed by the 29 presenters of the special DILI session during the meeting. This article presents the reviews findings, including the role of dietary supplements and Chinese herbal medicines in DILI.

Mechanism of action of vaccine therapy in murine hepatitis B virus carriers: vaccine-induced activation of antigen presenting dendritic cells

BACKGROUND/AIMS Vaccine therapy in which vaccine containing hepatitis B surface antigen (HBsAg) is injected has shown therapeutic activity (vaccine therapy) in some human and murine chronic hepatitis B virus (HBV)-carriers. Using HBV-transgenic mice (HBV-Tg), an animal model of the HBV-carrier state, the mechanism underlying the antiviral and immune modulatory capacity of vaccine therapy was studied. METHODS Placebo-controlled, double-blind trials of vaccine therapy were conducted in HBV-Tg; some HBV-Tg responded to the therapy, whereas others were non-responders. The titers of HBV-markers, the functions of lymphocytes and antigen presenting dendritic cells were compared between vaccine responders and vaccine non-responders. RESULTS The prevaccinated titers of HBsAg, hepatitis B e-antigen (HBeAg), HBV DNA and the responses of lymphocytes to polyclonal mitogens were almost unchanged between responders and non-responders, but the levels of proliferation of HBsAg-specific lymphocytes from non-responders was significantly lower than responders (p<0.05). The capacity of dendritic cells to induce proliferation of T cells and production of antibody to HBsAg (anti-HBs) was significantly higher in responders compared with non-responders (p<0.05). Injection with HBsAg resulted in upregulation of MHC class II and CD86 antigens (p<0.05) on dendritic cells and increased production of IL-12, IL-2 and TNF-alpha in cultures (p<0.05) in vaccine responders but not in non-responders. CONCLUSIONS The activation of dendritic cells following injection with vaccine containing HBsAg is the vital factor underlying the therapeutic potentiality of vaccine therapy in HBV carriers.

Infection and dysfunction of circulating blood dendritic cells and their subsets in chronic hepatitis C virus infection.

BackgroundTo understand interactions between dendritic cells (DCs) and viruses, in vitro-cultured monocyte-derived DCs are usually used for functional analyses. However, several recent studies indicate that circulating blood DCs are different from monocyte-derived DCs, both phenotypically and functionally. Indeed, circulating DCs act as functional antigen-presenting cells in vivo. This study was conducted to evaluate the function of circulating blood DCs in patients with chronic hepatitis C and to examine whether circulating DCs from these patients were infected by hepatitis C virus (HCV).MethodsThe phenotypes and biological functions of circulating DCs from patients with chronic hepatitis C (n = 27), patients with non-HCV chronic liver disease (n = 7), and normal volunteers (n = 13) were analyzed. The presence of the HCV genome sequence in circulating blood DCs and in subsets of circulating DCs (myeloid DCs and plasmacytoid DCs) in patients with chronic hepatitis C was assessed.ResultsThe stimulatory capacity of circulating DCs was significantly reduced in patients with chronic hepatitis C compared to patients with non-HCV chronic liver diseases and normal controls (P < 0.01). HCV RNA was identified in the overall population of circulating DCs, and in myeloid DCs and plasmacytoid DCs. Nucleotide sequences of the 5′ non-coding region of HCV RNA showed marked differences between paired samples of circulating DCs and sera from the same patients.ConclusionsOur results indicate the dysfunction and infection of circulatory blood DCs in chronic HCV infection. This may compromise the capacity of patients with hepatitis C to induce an effective antiviral immune response.