Diagnostic significance of lactate dehydrogenase in measles virus reinfection cases.

Lactate dehydrogenase (LDH) levels in measles virus (MeV) reinfection cases for the diagnosis of measles have not been extensively studied. Thus, we evaluated the significance of serum LDH in the immune response of patients with MeV reinfection in comparison with those of patients with primary infection. Among 70 patients who tested positive for MeV-RNA, 42 with high MeV-specific IgG avidity (HA) were suspected as cases of reinfection and 28 with low MeV-specific IgG (LA) were suspected as cases of primary infection. The viral loads in the HA group were also lower than those in the LA group (P < 0.001). The titers of MeV-specific IgM and IgG in the HA group were significantly lower and higher, respectively, than those in the LA group (P < 0.001). The total LDH and LDH isozyme levels were elevated in the LA group compared with those in the HA group (P < 0.001). Through receiver operating characteristic curve analyses, we determined that the area under the curve of total LDH level was 0.87 (95% CI 0.74-1.00) and that the discriminatory accuracy was high for total LDH and all isozymes. By stepwise binary logistic regression analysis considering MeV-specific IgG avidity, we developed a model using IgG, IgM, and total LDH as explanatory variables, which was optimal for distinguishing the LA and HA groups (adjusted R2 = 0.773, P < 0.001). Thus, the serum LDH level in addition to IgM and IgG may be useful parameters for differentiating MeV reinfection from primary infection.

Sindbis viral structural protein cytotoxicity on human neuroblastoma cells.

PURPOSE: Oncolytic viral therapy for neuroblastoma (NB) cells with Sindbis virus (SINV) is a promising strategy for treating high-risk NB. Here, we evaluated the possibility of using SINV structural proteins as therapeutic agents for NB since UV-inactivated SINV could induce cytopathogenic effects. METHODS: The cytotoxicity of UV-inactivated SINV toward human NB cell lines NB69, NGP, GOTO, NLF, SK-N-SH, SH-SY5Y, CHP134, NB-1, IMR32, and RT-BM-1 were analyzed. Apoptosis was confirmed by TUNEL assays. To determine the components of SINV responsible for the cytotoxicity of UV-inactivated SINV, expression vectors encoding the structural proteins, namely capsid, E2, and E1, were transfected in NB cells. Cytotoxicity was evaluated by MTT assays. RESULTS: UV-inactivated SINV elicited more significant cytotoxicity in NB69, NGP, and RT-BM-1 than in normal human fibroblasts. Results of the transfection experiments showed that all NB cell lines susceptible to UV-inactivated SINV were highly susceptible to the E1 protein, whereas fibroblasts transfected with vectors harboring capsid, E1, or E2 were not. CONCLUSIONS: We demonstrated that the cytotoxicity of the UV-inactivated SINV is due to apoptosis induced by the E1 structural protein of SINV, which can be used selectively as a therapeutic agent for NB.

Superinfection of hepatitis A virus in hepatocytes infected with hepatitis B virus.

Hepatitis A virus (HAV) infection is a major cause of acute hepatitis including acute liver failure. Hepatitis B infection (HBV) occurs worldwide, with the highest rates in Asian and African countries, and there are several reports that HAV infection may have a more severe clinical course in patients with chronic HBV infection. We previously demonstrated that Japanese miso extracts have inhibitory effects on HAV replication. In the present study, we examined the replication of HAV and HBV in a hepatocyte superinfection model and the inhibitory effects of Japanese miso extracts on both viruses. According to the results, HAV infection inhibited HBV replication in superinfected hepatocytes, and Japanese rice-koji miso extracts had inhibitory effects on HAV replication. Our findings provide useful information for clinicians in managing HAV infection in patients with chronic HBV infection.

Inhibitory effect of Japanese rice-koji miso extracts on hepatitis A virus replication in association with the elevation of glucose-regulated protein 78 expression.

Hepatitis A virus (HAV) infection is one of the major causes of acute hepatitis and acute liver failure in developing and developed countries. Although effective vaccines for HAV infection are available, outbreaks of HAV infection still cause deaths, even in developed countries. One approach to control HAV infection is prevention through diet, which can inhibit HAV propagation and replication. Glucose-regulated protein 78 (GRP78) is a member of the heat shock protein 70 family of molecular chaperone required for endoplasmic reticulum stress and stress-induced autophagy. We previously showed that the elevation of GRP78 expression inhibits HAV replication. It has been reported that Japanese miso extracts, which was made from rice-koji, enhance GRP78 expression. In the present study, we used human hepatoma Huh7 cells and human hepatocyte PXB cells to examine the efficacy of Japanese miso extracts as antiviral agents against HAV. Japanese miso extracts enhanced GRP78 expression and inhibited HAV replication in human hepatocytes. Together, these results demonstrate that Japanese miso extracts may partly modulate GRP78 expression and additively or synergistically work as antivirals against HAV infection. Japanese miso extracts can be used as effective dietary supplements for severe hepatitis A.

Free fatty acids or high-concentration glucose enhances hepatitis A virus replication in association with a reduction in glucose-regulated protein 78 expression.

Although the interaction between host and hepatitis A virus (HAV) factors could lead to severe hepatitis A, the exact mechanism of acute liver failure caused by HAV infection is not yet fully understood. The effects of metabolic diseases such as dyslipidemia or diabetes mellitus on HAV replication are still unknown. Here, we examined the effects of free fatty acids or high-concentration glucose on HAV replication and the effects on mitogen-activated protein kinase signaling pathway-related genes in human hepatocytes. We discovered a novel effect of free fatty acids or high-concentration glucose on HAV replication in association with a reduction in the expression of glucose-regulated protein 78 (GRP78). We also observed that thapsigargin induced GRP78 expression and inhibited HAV replication. These findings may provide a new interpretation of the relationship between metabolic diseases and severity of hepatitis A and suggest a new understanding of the mechanism of severe HAV infection.

Feasibility of viral dust infection via air movement and dispersion of dried viral particles from the floor.

The contributions of splash from vomiting and the dispersion of dried-up virus from a contaminated floor surface to community gastroenteritis outbreaks caused by Norovirus (NoV) were evaluated, using Feline calicivirus (FCV) as an NoV surrogate. There was no difference in the size distribution of FCV-containing particles around 0.75 µm) collected from a virus-sprayed chamber 1 and 12 hr after nebulization. FCV clearly dispersed after hitting a floor surface contaminated with dried virus. These results suggest that NoV can likely form airborne droplet nuclei, and dust may be the main route of infection transmission. J. Med. Virol. 89:931-935, 2017. © 2016 Wiley Periodicals, Inc.

Association of IFNL3 Genotype with Hepatic Steatosis in Chronic Hepatitis C Patients Treated with Peginterferon and Ribavirin Combination Therapy.

BACKGROUND: Genetic variation near the interferon lambda 3 (IFNL3) is known to be associated with response to pegylated interferon (pegIFN) and ribavirin combination therapy in patients with chronic hepatitis C virus (HCV) infection which is often accompanied by hepatic steatosis. AIMS: We examined whether this genetic variation is associated with host lipids and treatment response. METHODS: A total of 101 Japanese patients who had underwent liver biopsy before treatment with pegIFN and ribavirin for HCV genotype 1b infection were retrospectively analyzed for association between IFNL3 genotypes (rs8099917) and clinical factors including histopathological features of the liver. The presence of >5% steatosis in the liver specimen was defined as hepatic steatosis. RESULTS: Forty patients (40%) had liver steatosis before therapy. Patients with IFNL3 minor genotype (non-TT) showed lower low-density lipoprotein cholesterol level (p=0.0045), higher γ-glutamyl transpeptidase level (p=0.0003) and higher prevalence of hepatic steatosis (p=0.0002). Advanced fibrosis [odds ratio (OR) 4.63, p=0.03] and IFNL3 major genotype (OR 0.13, p=0.001) were 2 independent factors for determining the presence of hepatic steatosis. Among the factors associated with sustained virological response, IFNL3 genotype was the most significant predictor, as per multivariate analysis. CONCLUSIONS: Our results confirmed that IFNL3 genotype is associated with hepatic steatosis as well as IFN response.

Discrepancy between Hepatitis C Virus Genotypes and NS4-Based Serotypes: Association with Their Subgenomic Sequences.

Determination of hepatitis C virus (HCV) genotypes plays an important role in the direct-acting agent era. Discrepancies between HCV genotyping and serotyping assays are occasionally observed. Eighteen samples with discrepant results between genotyping and serotyping methods were analyzed. HCV serotyping and genotyping were based on the HCV nonstructural 4 (NS4) region and 5'-untranslated region (5'-UTR), respectively. HCV core and NS4 regions were chosen to be sequenced and were compared with the genotyping and serotyping results. Deep sequencing was also performed for the corresponding HCV NS4 regions. Seventeen out of 18 discrepant samples could be sequenced by the Sanger method. Both HCV core and NS4 sequences were concordant with that of genotyping in the 5'-UTR in all 17 samples. In cloning analysis of the HCV NS4 region, there were several amino acid variations, but each sequence was much closer to the peptide with the same genotype. Deep sequencing revealed that minor clones with different subgenotypes existed in two of the 17 samples. Genotyping by genome amplification showed high consistency, while several false reactions were detected by serotyping. The deep sequencing method also provides accurate genotyping results and may be useful for analyzing discrepant cases. HCV genotyping should be correctly determined before antiviral treatment.

Alteration of cell cycle progression by Sindbis virus infection.

We examined the impact of Sindbis virus (SINV) infection on cell cycle progression in a cancer cell line, HeLa, and a non-cancerous cell line, Vero. Cell cycle analyses showed that SINV infection is able to alter the cell cycle progression in both HeLa and Vero cells, but differently, especially during the early stage of infection. SINV infection affected the expression of several cell cycle regulators (CDK4, CDK6, cyclin E, p21, cyclin A and cyclin B) in HeLa cells and caused HeLa cells to accumulate in S phase during the early stage of infection. Monitoring SINV replication in HeLa and Vero cells expressing cell cycle indicators revealed that SINV which infected HeLa cells during G1 phase preferred to proliferate during S/G2 phase, and the average time interval for viral replication was significantly shorter in both HeLa and Vero cells infected during G1 phase than in cells infected during S/G2 phase.

The sirtuin inhibitor sirtinol inhibits hepatitis A virus (HAV) replication by inhibiting HAV internal ribosomal entry site activity.

Epigenetics plays a role in the regulation of gene expression. Epigenetic changes control gene expression at the transcriptional level. Our previous study suggested that the La protein, which is mainly localized in the nucleus, was associated with hepatitis A virus (HAV) internal ribosomal entry site (IRES)-mediated translation and HAV replication. The aim of this study was to investigate whether epigenetic compounds have effects on HAV IRES-mediated translation and HAV replication. Sirtinol, a sirtuin inhibitor, inhibited HAV IRES-mediated translation in COS7-HAV-IRES cells. Treatment with 10 µM sirtinol resulted in a significant reduction in the intracellular RNA levels of HAV HA11-1299 genotype IIIA in Huh7 cells. Epigenetic treatment with a sirtuin inhibitor may represent a new treatment option for HAV infection. In conclusion, epigenetic control was involved in HAV IRES-dependent translation and HAV replication. Special attention should also be paid to underlying viral diseases in the clinical use of epigenetic treatments for malignancies.

Association between hepatitis B virus and MHC class I polypeptide-related chain A in human hepatocytes derived from human-mouse chimeric mouse liver.

Due to the lack of efficient hepatitis B virus (HBV) infection systems, progress in understanding the role of innate immunity in HBV infection has remained challenging. Here we used human hepatocytes from a humanized severe combined immunodeficiency albumin promoter/enhancer driven-urokinase-type plasminogen activator mouse model for HBV infection. HBV DNA levels in culture medium from these human hepatocytes were 4.8-5.7 log IU/mL between day 16 and day 66 post-infection by HBV genotype C inoculum. HBV surface antigen (HBsAg) was also detected by chemiluminescent immunoassay from day 7 to day 66 post-infection. Western blot analysis revealed that major histocompatibility complex class I-related chain A (MICA), which plays a role in the innate immune system, was induced in HBV-infected human hepatocytes 27 days after infection compared with the uninfected control. MICA was reduced at day 62 and undetectable at day 90. Of interest, MICA expression by human hepatocytes increased after HBV infection and decreased before HBsAg loss. Human hepatocytes derived from chimeric mice with hepatocyte-humanized liver could support HBV genome replication. Further studies of the association between HBV replication and MICA induction should be conducted.

The JAK2 inhibitor AZD1480 inhibits hepatitis A virus replication in Huh7 cells.

The JAK2 inhibitor AZD1480 has been reported to inhibit La protein expression. We previously demonstrated that the inhibition of La expression could inhibit hepatitis A virus (HAV) internal ribosomal entry-site (IRES)-mediated translation and HAV replication in vitro. In this study, we analyzed the effects of AZD1480 on HAV IRES-mediated translation and replication. HAV IRES-mediated translation in COS7-HAV-IRES cells was inhibited by 0.1-1 µM AZD1480, a dosage that did not affect cell viability. Results showed a significant reduction in intracellular HAV HA11-1299 genotype IIIA RNA levels in Huh7 cells treated with AZD1480. Furthermore, AZD1480 inhibited the expression of phosphorylated-(Tyr-705)-signal transducer and activator of transcription 3 (STAT3) and La in Huh7 cells. Therefore, we propose that AZD1480 can inhibit HAV IRES activity and HAV replication through the inhibition of the La protein.

Oncolytic viral therapy for neuroblastoma cells with Sindbis virus AR339 strain.

PURPOSE: With current treatment regimens, high-risk neuroblastoma (NB) remains largely incurable. Oncolytic viral therapy uses replication-competent viruses, like Sindbis virus (SINV), to kill cancers. The SINV AR339 strain is blood borne and relatively non-virulent. We evaluated the feasibility of SINV AR339 for treating human NB. METHODS: The cytotoxicity and viral growth of SINV AR339 were evaluated for five human NB cell lines, SK-N-SH, IMR-32, LAN-5, GOTO, and RT-BM-1. SINV-induced apoptosis was confirmed by TUNEL assays and PARP-1 cleavage. In vivo effects of SINV on neuroblastoma cell xenografts in nude mice were assessed by intratumoral or intravenous SINV inoculation. RESULTS: In five human NB cell lines, SINV infections induced remarkable cytotoxicity. The mRNA expressions of anti-apoptotic genes, Bcl-2 and Bcl-xL, in LAN-5 and RT-BM-1, which were less sensitive to SINV infection, increased in response to SINV infection, while the other NB cell lines sensitive to SINV infection failed to respond. In nude mice, intratumoral and intravenous SINV inoculations caused significant regression of NB xenograft tumors. CONCLUSION: Our results suggested that SINV AR339 was significantly oncolytic against human NB. Thus, SINV showed promise as a novel therapy for treating NB.

Effect of Hepatitis C Virus Genotype 1b Core and NS5A Mutations on Response to Peginterferon Plus Ribavirin Combination Therapy.

We examined whether hepatitis C virus (HCV) genotype 1b core- and NS5A-region mutations are associated with response to peginterferon α-2b plus ribavirin combination therapy. A total of 103 patients with high HCV genotype 1b viral loads (≥ 100 KIU/mL) were treated with the combination therapy. Pretreatment mutations in the core region and interferon sensitivity determining region (ISDR) in the NS5A region were analyzed. In univariate analysis, arginine and leucine at positions 70 and 91 in the core region, defined as double wild (DW)-type, were associated with early virologic response (p = 0.002), sustained virologic response (SVR) (p = 0.004), and non-response (p = 0.005). Non-threonine at position 110 was associated with SVR (p = 0.004). Multivariate analysis showed the following pretreatment predictors of SVR: hemoglobin level ≥ 14 g/dL (odds ratio (OR) 6.2, p = 0.04); platelet count ≥ 14 × 104/mm³ (OR 5.2, p = 0.04); aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio < 0.9 (OR 6.17, p = 0.009); DW-type (OR 6.8, p = 0.02); non-threonine at position 110 (OR 14.5, p = 0.03); and ≥ 2 mutations in the ISDR (OR 12.3, p = 0.02). Patients with non-DW-type, non-threonine at position 110, and < 2 ISDR mutations showed significantly lower SVR rates than others (11/45 (24.4%) vs. 27/37 (73.0%), respectively; p < 0.001). SVR can be predicted through core and NS5A region mutations and host factors like hemoglobin, platelet count, and AST/ALT ratio in HCV genotype 1b-infected patients treated with peginterferon and ribavirin combination therapy.

Ultra-deep sequencing analysis of the hepatitis A virus 5'-untranslated region among cases of the same outbreak from a single source.

Hepatitis A virus (HAV) is a causative agent of acute viral hepatitis for which an effective vaccine has been developed. Here we describe ultra-deep pyrosequences (UDPSs) of HAV 5'-untranslated region (5'UTR) among cases of the same outbreak, which arose from a single source, associated with a revolving sushi bar. We determined the reference sequence from HAV-derived clone from an attendant by the Sanger method. Sixteen UDPSs from this outbreak and one from another sporadic case were compared with this reference. Nucleotide errors yielded a UDPS error rate of < 1%. This study confirmed that nucleotide substitutions of this region are transition mutations in outbreak cases, that insertion was observed only in non-severe cases, and that these nucleotide substitutions were different from those of the sporadic case. Analysis of UDPSs detected low-prevalence HAV variations in 5'UTR, but no specific mutations associated with severity in these outbreak cases. To our surprise, HAV strains in this outbreak conserved HAV IRES sequence even if we performed analysis of UDPSs. UDPS analysis of HAV 5'UTR gave us no association between the disease severity of hepatitis A and HAV 5'UTR substitutions. It might be more interesting to perform ultra-deep sequencing of full length HAV genome in order to reveal possible unknown genomic determinants associated with disease severity. Further studies will be needed.

Reactivation of hepatitis B virus in hematopoietic stem cell transplant recipients in Japan: efficacy of nucleos(t)ide analogues for prevention and treatment.

We retrospectively reviewed 413 recipients with hematologic malignancies who underwent hematopoietic stem cell transplantation (HSCT) between June 1986 and March 2013. Recipients with antibody to hepatitis B core antigen (anti-HBc) and/or to hepatitis B surface antigen (anti-HBs) were regarded as experiencing previous hepatitis B virus (HBV) infection. Clinical data of these recipients were reviewed from medical records. We defined ≥1 log IU/mL increase in serum HBV DNA from nadir as HBV reactivation in hepatitis B surface antigen (HBsAg)-positive recipients, and also defined ≥1 log IU/mL increase or re-appearance of HBV DNA and/or HBsAg as HBV reactivation in HBsAg-negative recipients. In 5 HBsAg-positive recipients, 2 recipients initially not administered with nucleos(t)ide analogues (NUCs) experienced HBV reactivation, but finally all 5 were successfully controlled with NUCs. HBV reactivation was observed in 11 (2.7%) of 408 HBsAg-negative recipients; 8 of these were treated with NUCs, and fortunately none developed acute liver failure. In 5 (6.0%) of 83 anti-HBc and/or anti-HBs-positive recipients, HBV reactivation occurred. None of 157 (0%) recipients without HBsAg, anti-HBs or anti-HBc experienced HBV reactivation. In HSCT recipients, HBV reactivation is a common event in HBsAg-positive recipients, or in HBsAg-negative recipients with anti-HBc and/or anti-HBs. Further attention should be paid to HSCT recipients with previous exposure to HBV.

Hepatitis B virus e antigen physically associates with receptor-interacting serine/threonine protein kinase 2 and regulates IL-6 gene expression.

We previously reported that hepatitis B virus (HBV) e antigen (HBeAg) inhibits production of interleukin 6 by suppressing NF-κB activation. NF-κB is known to be activated through receptor-interacting serine/threonine protein kinase 2 (RIPK2), and we examined the mechanisms of interleukin 6 regulation by HBeAg. HBeAg inhibits RIPK2 expression and interacts with RIPK2, which may represent 2 mechanisms through which HBeAg blocks nucleotide-binding oligomerization domain-containing protein 1 ligand-induced NF-κB activation in HepG2 cells. Our findings identified novel molecular mechanisms whereby HBeAg modulates intracellular signaling pathways by targeting RIPK2, supporting the concept that HBeAg could impair both innate and adaptive immune responses to promote chronic HBV infection.

PKR-NF-κB Pathway Upstream of IFN-ß Induction Is Dysregulated in Oncolytic Sindbis Virus-infected HeLa Cells.

BACKGROUND/AIM: Sindbis virus (SINV) is a naturally occurring oncolytic virus that kills cancer cells and is less harmful to normal cells. In this study, a recombinant SINV, which expressed green and blue fluorescent proteins, was used to precisely analyze SINV infection and replication. MATERIALS AND METHODS: Antiviral responses, including IFN-ß mRNA, protein kinase R (PKR), NF-B, and caspase 3/7, were analyzed in SINV-infected cancerous HeLa cells and normal human fibroblast TIG-1-20 cells. RESULTS: SINV could infect, replicate, and proliferate both in HeLa and TIG-1-20 cells, causing lytic infection only in HeLa cells. SINV grew preferentially in HeLa cells causing remarkable apoptosis. IFN-ß mRNA expression was suppressed in SINV-infected HeLa cells compared to that in TIG-1-20 cells. Further analyses of PKR and NF-B upstream of IFN-ß induction revealed that the compromised response in the PKR-NF-B pathway during early infection coincided with IFN induction suppression in HeLa cells. CONCLUSION: Dysregulation of PKR in HeLa cells is the determinant of SINV oncolysis.

Preparation and characterization of phospholipid-conjugated indocyanine green as a near-infrared probe.

We have rationally designed and synthesized a novel near-infrared (NIR) photoactivating probe, designated by iDOPE, in which an indocyanine green (ICG) fluorophore is covalently conjugated with a phospholipid moiety, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), to incorporate into liposome bilayers. NIR irradiation showed that iDOPE retained the optical and fluorescence properties of ICG and demonstrated photoactivator characteristics: fluorescence emission at around 820 nm in a solvent, singlet oxygen production, and concentration-dependent heat generation. Additionally, iDOPE was incorporated into liposome bilayers and maintained stable liposomally formulated iDOPE (LP-iDOPE) over 1week under physiological conditions. We also observed the tumor-specific biodistribution of LP-iDOPE of in vivo xenografts. These findings suggest that LP-iDOPE might be a promising tool for NIR optical imaging, photodynamic therapy, and photothermal therapy.

Hepatitis C Virus nonstructural 5A protein inhibits lipopolysaccharide-mediated apoptosis of hepatocytes by decreasing expression of Toll-like receptor 4.

BACKGROUND: Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) has been shown to modulate multiple cellular processes, including apoptosis. The aim of this study was to assess the effects of HCV NS5A on apoptosis induced by Toll-like receptor (TLR) 4 ligand, lipopolysaccharide (LPS). METHODS: Apoptotic responses to TLR4 ligands and the expression of molecules involved in TLR signaling pathways in human hepatocytes were examined with or without expression of HCV NS5A. RESULTS: HCV NS5A protected HepG2 hepatocytes against LPS-induced apoptosis, an effect linked to reduced TLR4 expression. A similar downregulation of TLR4 expression was observed in Huh-7-expressing genotype 1b and 2a. In agreement with these findings, NS5A inhibited the expression of numerous genes encoding for molecules involved in TLR4 signaling, such as CD14, MD-2, myeloid differentiation primary response gene 88, interferon regulatory factor 3, and nuclear factor-κB2. Consistent with a conferred prosurvival advantage, NS5A diminished the poly(adenosine diphosphate-ribose) polymerase cleavage and the activation of caspases 3, 7, 8, and 9 and increased the expression of anti-apoptotic molecules Bcl-2 and c-FLIP. CONCLUSIONS: HCV NS5A downregulates TLR4 signaling and LPS-induced apoptotic pathways in human hepatocytes, suggesting that disruption of TLR4-mediated apoptosis may play a role in the pathogenesis of HCV infection.