Substitutions of stem-loop subdomains in internal ribosome entry site of Senecavirus A:Impacts on rescue of sequence-modifying viruses

Senecavirus A(SVA)has a positive-sense,single-stranded RNA genome.Its 5´untranslated region harbors an internal ribosome entry site(IRES),comprising 10 larger or smaller stem-loop structures(including a pseudoknot)that have been demonstrated to be well conserved.However,it is still unclear whether each stem-loop subdomain,such as a single stem or loop,is also highly conserved.To clarify this issue in the present study,a set of 29 SVA cDNA clones were constructed by site-directed mutagenesis(SDM)on the IRES.The SDM-modified scenarios included:(1)stem-formed complementary sequences exchanging with each other;(2)loop transversion;(3)loop transition;and(4)point mutations.All cDNA clones were separately transfected into cells for rescuing viable viruses,whereas only four SVAs of interest could be recovered,and were genetically stable during 20 passages.One progeny grew significantly slower than the other three did.The dual-luciferase reporter assay showed that none of the SDM-modified IRESes significantly inhibited the IRES activity.Our previous study indicated that a single motif from any of the ten stem structures,if completely mutated,would cause the failure of virus recovery.Interestingly,our present study revealed three stem structures,whose individual complementary sequences could exchange with each other to rescue sequence-modifying SVAs.Moreover,one apical loop was demonstrated to have the ability to tolerate its own full-length transition,also having no impact on the recovery of sequence-modifying SVA.The present study suggested that not every stem-loop structure was strictly conserved in its conformation,while the full-length IRES itself was well conserved.This provides a new research direction on interaction between the IRES and many factors.

High-Value-Added Utilization of Turpentine:Screening of Anti-Influenza Virus Agents fromβ-Pinene Derivatives

Turpentine is a renewable and resourceful forest product.The deep processing and utilization of turpentine,particularly its primary componentβ-pinene,has garnered widespread attention.This study aimed to synthesize 40 derivatives ofβ-pinene,including nopinone,3-cyanopyridines of nopinone,myrtanyl acid,myrtanyl acylthioureas,and myrtanyl amides.We assessed the antiviral activities of theseβ-pinene derivatives against influenza virus A/Puerto Rico/8/34(H1N1)using the 3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method.Theβ-pinene derivatives were used before and after cellular infection with the influenza virus to evaluate their preventive and therapeutic effects against the H1N1 virus.The results showed that only compound 10o exhibited a preventive effect against the H1N1 virus with a half-maximal inhibitory concentration(IC50)value of 47.6μmol/L.Among the compounds,4e,4i,and 4l demonstrated therapeutic effects against cellular infection,with compound 4e displaying the most potent therapeutic effect(IC50=17.5μmol/L),comparable to the positive control ribavirin.These findings indicated that certainβ-pinene derivatives exhibited in vitro antiviral activity against the H1N1 influenza A virus,warranting further investigation as potential anti-influenza agents.

Glucose metabolism continuous deteriorating in male patients with human immunodeficiency virus accepted antiretroviral therapy for 156 weeks

BACKGROUND The dynamic characteristics of glucose metabolism and its risk factors in patients living with human immunodeficiency virus(PLWH)who accepted primary treatment with the efavirenz(EFV)plus lamivudine(3TC)plus tenofovir(TDF)(EFV+3TC+TDF)regimen are unclear and warrant investigation.AIM To study the long-term dynamic characteristics of glucose metabolism and its contributing factors in male PLWH who accepted primary treatment with the EFV+3TC+TDF regimen for 156 wk.METHODS This study was designed using a follow-up design.Sixty-one male treatmentnaive PLWH,including 50 cases with normal glucose tolerance and 11 cases with prediabetes,were treated with the EFV+3TC+TDF regimen for 156 wk.The glucose metabolism dynamic characteristics,the main risk factors and the differences among the three CD4+count groups were analyzed.RESULTS In treatment-naive male PLWH,regardless of whether glucose metabolism disorder was present at baseline,who accepted treatment with the EFV+3TC+TDF regimen for 156 wk,a continuous increase in the fasting plasma glucose(FPG)level,the rate of impaired fasting glucose(IFG)and the glycosylated hemoglobin(HbA1c)level were found.These changes were not due to insulin resistance but rather to significantly reduced isletβcell function,according to the homeostasis model assessment ofβcell function(HOMA-β).Moreover,the lower the baseline CD4+T-cell count was,the higher the FPG level and the lower the HOMA-βvalue.Furthermore,the main risk factors for the FPG levels were the CD3+CD8+cell count and viral load(VL),and the factors contributing to the HOMA-βvalues were the alanine aminotransferase level,VL and CD3+CD8+cell count.CONCLUSION These findings provide guidance to clinicians who are monitoring FPG levels closely and are concerned about IFG and decreased isletβcell function during antiretroviral therapy with the EFV+3TC+TDF regimen for long-term application.

Synthesis and in vitro-Anti-hepatitis B Virus Activities of Several Ethyl 5-Hydroxy-1H-indole-3-carboxylates

A series of ethyl 5-hydroxyindole-3-earboxylates 6a-10r was designed and synthesized. The structures of all the compounds were confirmed by IR, ^1H NMR, and MS and their anti-hepatitis B virus （HBV） activities were evaluated in 2.2.15 cells. Among them, compound 7g { ethyl 5-hydroxy-2- [ （ 3-methoxyphenylsulfinyl ） methyl ] -1-methyl-4- [ （4-methylpiperazin-1-yl） methyl ]-1H-indole-3-carboxylate} displays a significant anti-HBV activity, which is more potent than the positive control lamivudine.

Three sensitive and reliable serological assays for detection of potato virus A in potato plants

Vegetative propagation of seed potato often allows passaging of viruses to seed tubers,resulting in significant yield losses and reduction of potato tuber quality.Thus,virus detection approach is crucial for effective virus management programs and the production of virus-free seed potatoes.Among the reported potato-infecting viruses,potato virus A(PVA)is considered as one of the most important viruses in potato-growing regions worldwide.This study prepared four hybridoma lines secreting PVA-specific monoclonal antibodies(MAbs)(2D4,8E11,14A6 and 16H10)using purified PVA virions as an immunogen.Western blotting results indicated that all the four MAbs reacted strongly and specifically with the putative capsid protein of PVA.Using these four MAbs,this study developed antigen-coated plate enzyme-linked immunosorbent assay(ACP-ELISA),Dot-ELISA and Tissue print-ELISA for detection of PVA infection in potato plants.The results indicated that PVA can be detected in crude tissue extracts from infected potato plants diluted up to 1:327680(w/v,g m L^(-1))by ACP-ELISA or up to1:10240 by Dot-ELISA.The Tissue print-ELISA is the quickest and easiest approach among the three serological assays,and is more suitable for onsite large-scale potato screening programs.Further analyses of field-collected potato samples showed that the sensitivities and specificities of the three serological approaches were similar to those of RT-PCR in PVA detection and confirmed that PVA is currently widespread in Yunnan and Zhejiang provinces of China.Hence,the results strongly suggest that these highly sensitive serological approaches based on PVA-specific MAbs are useful and powerful for PVA-free seed potato production programs and PVA field surveys.

Complete nucleotide sequences of two isolates of Cherry virus A from sweet cherry in China

Cherry virus A（CVA） is a member of the genusCapilovirus, in the familyBetalfexiviridae. The infection rate of CVA was high in sweet cherry in China. We determined the complete nucleotide sequences of two isolates of CVA from Tai’an, Shan-dong Province, China using high ifdelity PCR enzymes and speciifc primer pairs for amplifying long fragments in RT-PCR and RACE. The ful-length sequences from isolates ChTA11 and ChTA12 are both 7382 nucleotide （nt） long, excluding the poly（A） tail, encode two open reading frames （ORFs） and have similar genome organization to the two isolates in Gen-Bank. The complete nucleotide sequence of ChTA11 is 98.2 and 81.2% nt identity to the isolates from Germany and India in GenBank, respectively, and the ChTA12 isolate is 98.2 and 81.0% similar. Analysis of the nucleotide and amino acid sequences showed that the domain of unknown function （DUF1717） is more variable compared with other domains. This is the ifrst report of the complete nucleotide sequences of CVA isolates infecting sweet cherry in China.

Receptor-mediated increase in rabies virus axonal transport

Rabies virus （RABV） of the rhabdoviridae family is a prototype neurotropic virus that causes a fatal disease, and is still a major risk mostly in developing countries. A key step in the RABV infection process is its arrival into the central nervous system （CNS）, for which it uses the cellular transport machinery. Neurons are irregular cells with a specialized anatomy, and often extend lengthy axons that may span over a meter long. In infected organisms, RABV virions enter the neuron periphery at the area of a bite and must overcome great distances in order to reach the peripheral neuron＇s cell body and from there,

Synthesis and Anti-influenza Virus Activity of Ethyl 6-Bromo-5-hydroxyindole-3-carboxylate Derivatives

A series of ethyl 6-bromo-5-hydroxyindole-3-carboxylate derivatives were synthesized and their in vitro anti-influenza virus activity was evaluated. All the compounds were characterized by 1H NMR and MS.

EXPERIMENTAL PRIMARY LIVER CANCER IN TREE SHREWS EXPOSED TO HUMAN HEPATITIS B VIRUS AND AFLATOXIN B_(1)

On the basis of the successful establishment of an animal model in tree shrews experimentally in fected with human hepatitis B virus (HHBV), a study on the hepatocarcinogenic effects of HHBV and aflatoxin B1 (AFB1) by using this animal model was conducted through a lifelong experiment. Among 41 tree shrews exposed to AFB1, 17 were experimentally infected by HHBV and 24 were uninfected. After 158 weeks, significant difference of primary liver cancer (PLC) incidence was present between the HHBV infected (52.94%) and uninfected (12.5%) groups (p<0.05). No difference was found between these two groups in the amount of AFB4 ingestion. Moreover, 1/9 of the tree shrews infected only by HHBV but not exposed to AFB4 developed PLC. No PLC was found in 6 tree shrews that had neither been infected with HHBV nor been exposed to AFB4. These results suggest the possible etiologic relationship between HHBV infection and PLC, as well as the synergetic effects of HHBV and AFB4 during PLC development.

Synthesis and in vitro Anti-hepatitis B Virus Activity of Some Ethyl 5-Hydroxy-4-substituted Aminomethyl-2-sulfinylmethyl-1H-indole-3-carboxylates

A novel series of ethyl 5-hydroxy-4-substituted aminomethyl-2-sulfinylmethyl-lH-indole-3-carboxylates 8a--8j and 11e--11f was synthesized and evaluated in HepG2.2.15 cells for their anti-hepatitits B virus（HBV） activity and cytotoxicity. Among them, six compounds showed more potent inhibitory activity than lamivudine. Compound 8e exhibited the most significant anti-HBV activity with an IC50 value of 1.62 μmol/L, which was 33-times more potent than the reference drug lamivudine（IC50=54.78μmol/L）.

ESTABLISHMENT OF A CELL LINE INFECTED WITH SRS MOUSE LEUKEMIA VIRUS AND ITS BIOLOGICAL CHARACTERISTICS

NIH/3T3 cells were infected with a cell-free extract from the mouse SRS ascltic tumor and propagated at vitro. Experimental results showed that type A and type C virus particles were observed in the cytoplasm of infected NIH/ 3T3 cells by electron-microscopy, X-C assay and reverse transcriptase were both positive. Free proviral-DN A of the leukemia vims was found in the infected NIH/3T3 cell by Southern blot hybridization.Morphologically, the NIH/3T3 cells infected in vitro appeared spherical and formed monolayer cell colonies of various sizes after 24 - 48 hours. When the cultured cells were Inoculated into nude mice (BALB/ c, nu nu ) subcutaneously, flbrosarcoma was Induced, 100%. Inoculation of the cell-free extract of the same cultured cells into Inbred SW-1 newborn mice, resulted in the production of lymphocytic leukemia and lymphoma in 52. 3% within 191 days.

Comparison on Detection Results of PRV Wild Virus Antibody Provided by Different Institutions

The detection results from different institutions were performed at the first stage of PRV wild virus antibody supervision in swine breeding. The serum samples were collected from 71 individuals and each individual was sampled twice at one week interval. The results showed that the positive coincidences for gE antibody between two institutions were 35.71% and 45.45 % ：espectively, with the total detection coincidences of 87.32% and 91.55% correspondingly. The positive coincidences for gE antibody between the two detections of each institution were 40.00% and 75.00% respectively, with the total detection coincidences of 87.32% and 97.18% correspondingly. It indicates that it is very necessary to screen the detection institution at the first supervision stage of PRV wild vires for swine population.

Evaluation of antiviral activities of Houttuynia cordata Thunb.extract,quercetin,quercetrin and cinanserin on murine coronavirus and dengue virus infection

Objective:To evaluate the in vitro activities of the ethyl acetate(EA) fraction of Houttuynia cordata(H.cordata) Thunb.(Saururaceae) and three of its constituent flavonoids(quercetin.quercitrin and rutin) against murine coronavirus and dengue virus(DENV).Methods:The antiviral activities of various concentrations of the EA fraction of H.cordata and flavonoids were assessed using virus neutralization tests against mouse hepatitis virus(MHV) and DENV type 2(DENV-2).Cinanserin hydrochloride was also tested against MHV.The EA fraction of H.cordata was tested for acute oral toxicity in C57BL/6 mice.Results:The EA fraction of H.cordata inhibited viral infectivity up to 6 d.Cinanserin hydrochloride was able to inhibit MHV for only 2 d.The 50%inhibitory concentrations(IC_(50)) of the EA fraction of H.cordata added before the viral adsorption stage were 0.98 μg/mL for MHV and 7.50 μg/mL for DENV-2with absence of cytotoxicity.The mice fed with the EA fraction up to 2 000 mg/kg did not induce any signs of acute toxicity,with normal histological features of major organs.Certain flavonoids exhibited comparatively weaker antiviral activity,notably quercetin which could inhibit both MHV and DENV-2.This was followed by quercitrin which could inhibit DENV-2but not MHV,whereas rutin did not exert any inhibitory effect on either virus.When quercetin was combined with quercitrin,enhancement of anti-DENV-2 activity and reduced cytotoxicity were observed.However,the synergistic efficacy of the flavonoid combination was still less than that of the EA fraction.Conclusions:The compounds in H.cordata contribute to the superior antiviral efficacy of the EA fraction which lacked cytotoxicity in vitro and acute toxicity in vim.H.cordata has much potential for the development of antiviral agents against coronavirus and dengue infections.

Hepatitis B virus and hepatitis C virus dual infection

Hepatitis B virus(HBV)and hepatitis C virus(HCV)share common mode of transmission and both are able to induce a chronic infection.Dual HBV/HCV chronic coinfection is a fairly frequent occurrence,especially in high endemic areas and among individuals at high risk of parenterally transmitted infections.The intracellular interplay between HBV and HCV has not yet been sufficiently clarified,also due to the lack of a proper in vitro cellular model.Longitudinal evaluation of serum HBV DNA and HCV RNA amounts has revealed that complex virological profiles may be present in coinfected patients.Dual HBV/HCV infection has been associated to a severe course of the liver disease and to a high risk of developing hepatocellular carcinoma.Despite the clinical importance,solid evidence and clear guidelines for treatment of this special population are still lacking.This review summarizes the available data on the virological and clinical features as well as the therapeutic options of the dual HBV/HCV infection,and highlights the aspects that need to be better clarified.

Genetic variation of hepatitis B virus and its significance forpathogenesis

Hepatitis B virus(HBV)has a worldwide distribution and is endemic in many populations.Due to its unique life cycle which requires an error-prone reverse transcriptase for replication,it constantly evolves,resulting in tremendous genetic variation in the form of genotypes,sub-genotypes,and mutations.In recent years,there has been considerable research on the relationship between HBV genetic variation and HBV-related pathogenesis,which has profound implications in the natural history of HBV infection,viral detection,immune prevention,drug treatment and prognosis.In this review,we attempted to provide a brief account of the influence of HBV genotype on the pathogenesis of HBV infection and summarize our current knowledge on the effects of HBV mutations in different regions on HBV-associated pathogenesis,with an emphasis on mutations in the pre S/S proteins in immune evasion,occult HBV infection and hepatocellular carcinoma(HCC),mutations in polymerase in relation to drug resistance,mutations in HBV core and e antigen in immune evasion,chronicalization of infection and hepatitis B-related acute-on-chronic liver failure,and finally mutations in HBV x proteins in HCC.

Hepatitis B virus and hepatitis C virus play different prognostic roles in intrahepatic cholangiocarcinoma: A meta-analysis

AIM: To identify the prognostic value of hepatitis B virus(HBV) and hepatitis C virus(HCV) infections in patients with intrahepatic cholangiocarcinoma.METHODS: A search was performed for relevant publications in Pub Med, EMBASE and Web of Science databases. The pooled effects were calculated from the available information to identify the relationship between HBV or HCV infection and the prognosis and clinicopathological features. The χ2 and I2 tests were used to evaluate heterogeneity between studies. Pooled hazard ratios(HRs) with 95% confidence intervals(CIs) were calculated by a fixed-effects model, if no heterogeneity existed. If there was heterogeneity, a random-effects model was applied.RESULTS: In total, 14 studies involving 2842 cases were enrolled in this meta-analysis. The patients with HBV infection presented better overall and diseasefree survival, and the pooled HRs were significant at 0.76(95%CI: 0.70-0.83) and 0.78(95%CI: 0.66-0.94), respectively. Additionally, our study revealed that HCV infection was correlated with shortened overall survival in comparison with the control group(HR = 2.64, 95%CI: 1.77-3.93). We also found that HBV infection occurred more frequently in male patients [odds ratio(OR) = 1.91, 95%CI: 1.06-3.44] and was correlated with higher levels of serum aspartate transaminase(AST) and alpha-fetoprotein(AFP)(OR = 1.93, 95%CI: 1.11-3.35; OR = 3.86, 95%CI: 2.58-5.78) and a lower level of serum carbohydrate antigen 19-9(CA19-9)(OR = 0.47, 95%CI: 0.34-0.65). Moreover, HBV infection was associated with cirrhosis(OR = 6.44, 95%CI: 4.33-9.56), a higher proportion of capsule formation(OR = 6.04, 95%CI: 3.56-10.26), and a lower rate of lymph node metastasis(OR = 0.39, 95%CI: 0.25-0.58). No significant publication bias was seen in any of the enrolled studies.CONCLUSION: HBV infection may indicate a favorable prognosis in patients with intrahepatic cholangiocarcinoma, while HCV infection suggests a poor prognosis.

Human immunodeficiency virus and hepatotropic viruses comorbidities as the inducers of liver injury progression

Hepatotropic viruses induced hepatitis progresses much faster and causes more liver-related health problems in people co-infected with human immunodeficiency virus(HIV). Although treatment with antiretroviral therapy has extended the life expectancy of people with HIV, liver disease induced by hepatitis B virus(HBV) and hepatitis C virus(HCV) causes significant numbers of non-acquired immune deficiency syndrome(AIDS)-related deaths in coinfected patients. In recent years, new insights into the mechanisms of accelerated fibrosis and liver disease progression in HIV/HCV and HIV/HBV co-infections have been reported. In this paper, we review recent studies examining the natural history and pathogenesis of liver disease in HIV-HCV/HBV co-infection in the era of direct acting antivirals(DAA) and antiretroviral therapy(ART). We also review the novel therapeutics for management of HIV/HCV and HIV/HBV coinfected individuals.

Hepatitis B virus and micro RNAs:Complex interactions affecting hepatitis B virus replication and hepatitis B virusassociated diseases

Chronic infection with the hepatitis B virus(HBV) is the leading risk factor for the development of hepatocellular carcinoma(HCC). With nearly 750000 deaths yearly, hepatocellular carcinoma is the second highest cause of cancer-related death in the world. Unfortunately, the molecular mechanisms that contribute to the development of HBV-associated HCC remain incompletely understood. Recently, micro RNAs(mi RNAs), a family of small non-coding RNAs that play a role primarily in post-transcriptional gene regulation, have been recognized as important regulators of cellular homeostasis, and altered regulation of mi RNA expression has been suggested to play a significant role in virus-associated diseases and the development of many cancers. With this in mind, many groups have begun to investigate the relationship between mi RNAs and HBV replication and HBV-associated disease. Multiple findings suggest that some mi RNAs, such as mi R-122, and mi R-125 and mi R-199 family members, are playing a role in HBV replication and HBV-associated disease, including the development of HBV-associated HCC. In this review, we discuss the current state of our understanding of the relationship between HBV and mi RNAs, including how HBV affects cellular mi RNAs, how these mi RNAs impact HBV replication, and the relationship between HBV-mediated mi RNA regulation and HCC development. We also address the impact of challenges in studying HBV, such as the lack of an effective model system for infectivity and a reliance on transformed cell lines, on our understanding of the relationship between HBV and mi RNAs, and proposepotential applications of mi RNA-related techniques that could enhance our understanding of the role mi RNAs play in HBV replication and HBV-associated disease, ultimately leading to new therapeutic options and improved patient outcomes.

Occult hepatitis B virus and hepatocellular carcinoma

Occult hepatitis B virus(HBV)infection(OBI)is a challenging pathobiological and clinical issue that has been widely debated for several decades.By definition,OBI is characterized by the persistence of HBV DNA in the liver tissue(and in some cases also in the serum)in the absence of circulating HBV surface antigen(HBsAg).Many epidemiological and molecular studies have indicated that OBI is an important risk factor for hepatocellular carcinoma(HCC)development.OBI may exert direct pro-oncogenic effects through the activation of the same oncogenic mechanisms that are activated in the course of an HBsAg-positive infection.Indeed,in OBI as in HBV-positive infection,HBV DNA can persist in the hepatocytes both integrated into the host genome as well as free episome,and may maintain the capacity to produce proteins-mainly X protein and truncated preS-S protein-provided with potential transforming properties.Furthermore,OBI may indirectly favor HCC development.It has been shown that the persistence of very low viral replicative activity during OBI may induce mild liver necro-inflammation continuing for life,and substantial clinical evidence indicates that OBI canaccelerate the progression of liver disease towards cirrhosis that is considered the most important risk factor for HCC development.

Antiviral therapy for hepatitis B virus associated hepatic failure

BACKGROUND: Chronic hepatitis B virus (HBV) infection remains a major global health issue, and the prognosis of patients with HBV-associated fulminant hepatic failure is extremely poor. The application of antiviral therapies has led to significant improvements in patient outcomes. This article aimed to review the current strategies in antiviral treatment of HBV-associated fulminant hepatic failure. DATA SOURCES: Literature search was conducted using PubMed on the related subjects. Part of the data was from the most recent work of the authors' laboratory. RESULTS: Hepatitis B immunoglobulin in prevention of recurrent HBV infection after orthotopic liver transplantation (OLT) has been proven effective. However, its cost is high, and significant side effects have been found to induce viral mutations. Lamivudine has a potent suppression for HBV replication and an excellent safety profile in decompensated cirrhotic patients, but its major drawback is the high rate of drug-resistance. Adefovir is effective for lamivudine-resistance strains in the post-OLT situation, and its drug-resistance rate is relatively low. Combination therapies such as hepatitis B immunoglobulin combined with lamivudine and lamivudine combined with adefovir have been widely adopted for prophylaxis against HBV recurrence of infection after OLT. Entecavir, telbivudine, tenofovir and other newer agents have been widely used in antiviral therapy. CONCLUSIONS: The prognosis of HBV-associated fulminant hepatic failure is being transformed by developments in antiviral therapy. However, it should be noticed that HBV is controlled but never eliminated, and drug-resistance still remains a major issue. Hopefully, newer strategies may help to solve these problems.