Aquatic viruses include infected viruses in aquatic animals, plants and microorganisms, and free-floating viruses(virioplankton)in water environments. In the last three decades, a huge number of aquatic viruses, espec...Aquatic viruses include infected viruses in aquatic animals, plants and microorganisms, and free-floating viruses(virioplankton)in water environments. In the last three decades, a huge number of aquatic viruses, especially diverse free-floating viruses,including cyanophages, phycoviruses, archaea viruses, giant viruses, and even virophages, have been identified by virological experiments and metagenomic analyses. Based on a comprehensive introduction of aquatic virus classification and their morphological and genetic diversity, here, we summarize and outline main virus species, their evolutionary contribution to aquatic communities through horizontal gene transfer, and their ecological roles for cyanobacterial bloom termination and global biogeochemical cycling in freshwater and marine ecosystems. Thereby, some novel insights of aquatic viruses and virus-host interactions, especially their evolutionary contribution and ecological rolesin diverse aquatic communities and ecosystems, are highlighted in this review.展开更多
Hepatitis B virus (HBV) infection,a major public health problem,causes acute and chronic hepatitis that is often complicated by liver cirrhosis and hepatocellular carcinoma.The pathogenic mechanisms of HBV-related liv...Hepatitis B virus (HBV) infection,a major public health problem,causes acute and chronic hepatitis that is often complicated by liver cirrhosis and hepatocellular carcinoma.The pathogenic mechanisms of HBV-related liver disease are not well understood,and the current licensed therapies are not effective in permanently clearing virus from the circulation.In recent years,the role of micro-ribonucleic acids (miRNAs) in HBV infection has attracted great interest.Cellular miRNAs can influence HBV replication directly by binding to HBV transcripts and indirectly by targeting cellular factors relevant to the HBV life cycle.They are also involved in the regulation of cellular genes and signaling pathways that have critical roles in HBV pathogenesis.HBV infection,in turn,can trigger changes in cellular miRNA expression that are associated with distinctive miRNA expression profiles depending on the phase of liver disease.These alterations in miRNA expression have been linked to disease progression and hepatocarcinogenesis.We provide here an up to date review regarding the field of miRNAs and HBV interplay and highlight the potential utility of miRNAs as diagnostic biomarkers and therapeutic targets for the management of HBV-related liver disease.展开更多
The majority of individuals exposed to hepatitis C virus(HCV) establish a persistent infection,which is a leading cause of chronic liver disease,cirrhosis and hepatocellular carcinoma.Major progress has been made duri...The majority of individuals exposed to hepatitis C virus(HCV) establish a persistent infection,which is a leading cause of chronic liver disease,cirrhosis and hepatocellular carcinoma.Major progress has been made during the past twenty-five years in understanding the HCV life cycle and immune responses against HCV infection.Increasing evidence indicates that host genetic factors can significantly influence the outcome of HCV infection and the response to interferon alpha-based antiviral therapy.The arrival of highly effective and convenient treatment regimens for patients chronically infected with HCV has improved prospects for the eradication of HCV worldwide.Clinical trials are evaluating the best anti-viral drug combination,treatment doses and duration.The new treatments are better-tolerated and have shown success rates of more than 95%.However,the recent breakthrough in HCV treatment raises new questions and challenges,including the identification of HCVinfected patients and to link them to appropriate health care,the high pricing of HCV drugs,the emergence of drug resistance or naturally occurring polymorphism in HCV sequences which can compromise HCV treatment response.Finally,we still do not have a vaccine against HCV.In this concise review,we will highlight the progress made in understanding HCV infection and therapy.We will focus on the most significant unsolved problems and the key future challenges in the management of HCV infection.展开更多
MicroRNAs(miRNAs) are a class of small noncoding RNAs that post-transcriptionally regulate the expression of many target genes via mRNA degradation or translation inhibition. Many studies have shown that miRNAs are in...MicroRNAs(miRNAs) are a class of small noncoding RNAs that post-transcriptionally regulate the expression of many target genes via mRNA degradation or translation inhibition. Many studies have shown that miRNAs are involved in the modulation of gene expression and replication of hepatitis B virus(HBV) and hepatitis C virus(HCV) and play a pivotal role in host-virus interactions. Increasing evidence also demonstrates that viral infection leads to alteration of the miRNA expression profile in hepatic tissues or circulation. The deregulated miRNAs participate in hepatocellular carcinoma(HCC)initiation and progression by functioning as oncogenes or tumor suppressor genes by targeting various genes involved in cancer-related signaling pathways. The distinct expression pattern of miRNAs may be a useful marker for the diagnosis and prognosis of virus-related diseases considering the limitation of currently used biomarkers. Moreover, the role of deregulated miRNA in host-virus interactions and HCC development suggested that miRNAs may serve as therapeutic targets or astools. In this review, we summarize the recent findings about the deregulation and the role of miRNAs during HBV/HCV infection and HCC development, and we discuss the possible mechanism of action of miRNAs in the pathogenesis of virus-related diseases. Furthermore, we discuss the potential of using miRNAs as markers for diagnosis and prognosis as well as therapeutic targets and drugs.展开更多
引起乙型肝炎病毒(hepatitis B virus,HBV)感染后慢性化的因素有宿主因素和病毒因素。宿主因素主要有免疫功能、细胞凋亡蛋白抑制因子(cellular inhibitor of apoptosis proteins,c IAPs)以及HLA基因多态性等使宿主不能产生有效的抗病...引起乙型肝炎病毒(hepatitis B virus,HBV)感染后慢性化的因素有宿主因素和病毒因素。宿主因素主要有免疫功能、细胞凋亡蛋白抑制因子(cellular inhibitor of apoptosis proteins,c IAPs)以及HLA基因多态性等使宿主不能产生有效的抗病毒反应;病毒因素主要包括乙肝病毒基因型、乙肝病毒变异、乙肝病毒抗原等,导致HBV持续存在肝细胞中不能被清除。本文综合最新国内外进展对乙肝病毒感染后慢性化的发生机制进行综述。展开更多
甲型流感病毒(influenza A virus,IAV)严重威胁人类健康。病毒核心是核糖核蛋白复合物(viral ribonucleoprotein complexes,vRNPs),是病毒基因组转录和复制的最小功能单位。核蛋白(nucleoprotein,NP)是vRNP的重要组成部分之一,在流感病...甲型流感病毒(influenza A virus,IAV)严重威胁人类健康。病毒核心是核糖核蛋白复合物(viral ribonucleoprotein complexes,vRNPs),是病毒基因组转录和复制的最小功能单位。核蛋白(nucleoprotein,NP)是vRNP的重要组成部分之一,在流感病毒整个生命周期起着关键作用。机体存在多种宿主因子通过NP影响病毒增殖。本文就通过NP影响vRNP核输入、病毒基因组转录和复制、vRNP核输出以及vRNP组装这几个方面的宿主因子进行综述,以期为治疗IAV新靶点的发现及新药物的研发提供参考。展开更多
Hepatitis B virus(HBV)infection is a global public health problem that causes persistent liver diseases such as chronic hepatitis,cirrhosis,and hepatocellular carcinoma.A large amount of people die annually from HBV i...Hepatitis B virus(HBV)infection is a global public health problem that causes persistent liver diseases such as chronic hepatitis,cirrhosis,and hepatocellular carcinoma.A large amount of people die annually from HBV infection.However,the pathogenesises of the HBV-related diseases are ill defined and the therapeutic strategies for the diseases are less than optimum.The recently discovered microRNAs(miRNAs)are tiny noncoding RNAs that regulate gene expression primarily at the post-transcriptional level by binding to mRNAs.miRNAs contribute to a variety of physiological and pathological processes.A number of miRNAs have been found to play a pivotal role in the host-virus interaction including host-HBV interaction.Numerous studies have indicated that HBV infection could change the cellular miRNA expression patterns and different stages of HBV associated disease have displayed distinctive miRNA profiles.Furthermore,the differential expressed miRNAs have been found involved in the progression of HBV-related diseases,for instance some miRNAs are involved in liver tumorigenesis and tumor metastasis.Studies have also shown that the circulating miRNA in serum or plasma might be a very useful biomarker for the diagnosis and prognosis of HBV-related diseases.In addition,miRNA-based therapy strategies have attracted increasing attention,indicating a promising future in the treatment of HBV-related diseases.展开更多
During virus infection, viral RNAs and mRNAs function as blueprints for viral protein synthesis and possibly as pathogen-associated molecular patterns （PAMPs） in innate immunity. Here, considering recent research pr...During virus infection, viral RNAs and mRNAs function as blueprints for viral protein synthesis and possibly as pathogen-associated molecular patterns （PAMPs） in innate immunity. Here, considering recent research progress in microRNAs （miRNAs） and competitive endogenous RNAs （ceRNAs）, we speculate that viral RNAs act as sponges and can sequester endogenous miRNAs within infected cells, thus cross-regulating the stability and translational efficiency of host mRNAs with shared miRNA response elements. This cross-talk and these reciprocal interactions between viral RNAs and host mRNAs are termed ＂competitive viral and host RNAs＂ （cvhRNAs）. We further provide recent experimental evidence for the existence of cvhRNAs networks in hepatitis B virus （HBV）, as well as Her- pesvirus saimiri （HVS）, lytic murine cytomegalovirus （MCMV） and human cytomegalovirus （HCMV） infec- tions. In addition, the cvhRNA hypothesis also pre- dicts possible cross-regulation between host and other viruses, such as hepatitis C virus （HCV）, HIV, influenza virus, human papillomaviruses （HPV）. Since the interaction between miRNAs and viral RNAs also inevitably leads to repression of viral RNA function, we speculate that virus may evolve either to employ cvhRNA networks or to avoid miRNA targeting for optimal fitness within the host. CvhRNA networks may therefore play a fundamental role in the regulation of viral replication, infection establishment, and viral pathogenesis.展开更多
The current therapeutic regimen to combat chronic hepatitis C is not optimal due to substantial side effects and the failure of a significant proportion of patients to achieve a sustained virological response. Recentl...The current therapeutic regimen to combat chronic hepatitis C is not optimal due to substantial side effects and the failure of a significant proportion of patients to achieve a sustained virological response. Recently developed direct-acting antivirals targeting hepatitis C virus (HCV) enzymes reportedly increase the virologic response to therapy but may lead to a selection of drug-resistant variants. Besides direct-acting antivirals, another promising class of HCV drugs in development include host targeting agents that are responsible for interfering with the host factors crucial for the viral life cycle. A family of host proteins known as DEAD-box RNA helicases, characterized by nine conserved motifs, is known to play an important role in RNA metabolism. Several members of this family such as DDX3, DDX5 and DDX6 have been shown to play a role in HCV replication and this review will summarize our current knowledge on their interaction with HCV. As chronic hepatitis C is one of the leading causes of hepatocellular carcinoma, the involvement of DEAD-box RNA helicases in the development of HCC will also be highlighted. Continuing research on the interaction of host DEAD-box proteins with HCV and the contribution to viral replication and pathogenesis could be the panacea for the development of novel therapeutics against HCV.展开更多
Hepatitis C virus(HCV)infection is a global health problem,with an estimated 170 million people being chronically infected.HCV cell entry is a complex multi-step process,involving several cellular factors that trigger...Hepatitis C virus(HCV)infection is a global health problem,with an estimated 170 million people being chronically infected.HCV cell entry is a complex multi-step process,involving several cellular factors that trigger virus uptake into the hepatocytes.The high-density lipoprotein receptor scavenger receptor class B type I,tetraspanin CD81,tight junction protein claudin-1,and occludin are the main receptors that mediate the initial step of HCV infection.In addition,the virus uses cell receptor tyrosine kinases as entry regulators,such as epidermal growth factor receptor and ephrin receptor A2.This review summarizes the current understanding about how cell surface molecules are involved in HCV attachment,internalization,and membrane fusion,and how host cell kinases regulate virus entry.The advances of the potential antiviral agents targeting this process are introduced.展开更多
Tomato brown rugose fruit virus(ToBRFV) is a novel tobamovirus firstly reported in 2015 and poses a severe threat to the tomato industry. So far, it has spread to 10 countries in America, Asia, and Europe. In 2019, To...Tomato brown rugose fruit virus(ToBRFV) is a novel tobamovirus firstly reported in 2015 and poses a severe threat to the tomato industry. So far, it has spread to 10 countries in America, Asia, and Europe. In 2019, ToBRFV was identified in Shandong Province(ToBRFV-SD), China. In this study, it was shown that ToBRFV-SD induced mild to severe mosaic and blistering on leaves, necrosis on sepals and pedicles, and deformation, yellow spots, and brown rugose necrotic lesions on fruits. ToBRFV-SD induced distinct symptoms on plants of tomato, Capsicum annumm, and Nicotiana benthamiana, and caused latent infection on plants of Solanum tuberosum, Solanum melongena, and N. tabacum cv. Zhongyan 102. All the 50 tomato cultivars tested were highly sensitive to ToBRFV-SD. The complete genomic sequence of ToBRFV-SD shared the highest nucleotide and amino acid identities with isolate IL from Israel. In the phylogenetic tree constructed with the complete genomic sequence, all the ToBRFV isolates were clustered together and formed a sister branch with tobacco mosaic virus(TMV). Furthermore, a quadruplex RT-PCR system was developed that could differentiate ToBRFV from other economically important viruses affecting tomatoes, such as TMV, tomato mosaic virus, and tomato spotted wilt virus. The findings of this study enhance our understanding of the biological and molecular characteristics of ToBRFV and provide an efficient and effective detection method for multiple infections, which is helpful in the management of ToBRFV.展开更多
Severe fever with thrombocytopenia syndrome(SFTS)caused by the SFTS virus(SFTSV)is an emerging disease in East Asia with a fatality rate of up to 30%.However,the viral-host interaction of SFTSV remains largely unknown...Severe fever with thrombocytopenia syndrome(SFTS)caused by the SFTS virus(SFTSV)is an emerging disease in East Asia with a fatality rate of up to 30%.However,the viral-host interaction of SFTSV remains largely unknown.The heat-shock protein 90(Hsp90)family consists of highly conserved chaperones that fold and remodel proteins and has a broad impact on the infection of many viruses.Here,we showed that Hsp90 is an important host factor involved in SFTSV infection.Hsp90 inhibitors significantly reduced SFTSV replication,viral protein expression,and the formation of inclusion bodies consisting of nonstructural proteins(NSs).Among viral proteins,NSs appeared to be the most reduced when Hsp90 inhibitors were used,and further analysis showed that their translation was affected.Co-immunoprecipitation of NSs with four isomers of Hsp90 showed that Hsp90βspecifically interacted with them.Knockdown of Hsp90βexpression also inhibited replication of SFTSV.These results suggest that Hsp90βplays a critical role during SFTSV infection and could be a potential target for the development of drugs against SFTS.展开更多
Influenza A virus(IAV),responsible for seasonal epidemics and recurring pandemics,represents a global threat to public health.Given the risk of a potential IAV pandemic,it is increasingly important to better understan...Influenza A virus(IAV),responsible for seasonal epidemics and recurring pandemics,represents a global threat to public health.Given the risk of a potential IAV pandemic,it is increasingly important to better understand virushost interactions and develop new anti-viral strategies.Here,we reported nonmuscle myosin IIA(MYH9)-mediated regulation of IAV infection.MYH9 depletion caused a profound inhibition of IAV infection by reducing viral attachment and internalization in human lung epithelial cells.Surprisingly,overexpression of MYH9 also led to a significant reduction in viral productive infection.Interestingly,overexpression of MYH9 retained viral attachment,internalization,or uncoating,but suppressed the viral ribonucleoprotein(vRNP)activity in a minigenome system.Further analyses found that excess MYH9 might interrupt the formation of vRNP by interacting with the viral nucleoprotein(NP)and result in the reduction of the completed vRNP in the nucleus,thereby inhibiting subsequent viral RNA transcription and replication.Together,we discovered that MYH9 can interact with IAV NP protein and engage in the regulation of vRNP complexes,thereby involving viral replication.These findings enlighten new mechanistic insights into the complicated interface of host-IAV interactions,ultimately making it an attractive target for the generation of antiviral drugs.展开更多
The spike protein(S)of SARS-CoV-2 is responsible for viral attachment and entry,thus a major factor for host suscep-tibility,tissue tropism,virulence and pathogenicity.The S is divided with S1 and S2 region,and the S1...The spike protein(S)of SARS-CoV-2 is responsible for viral attachment and entry,thus a major factor for host suscep-tibility,tissue tropism,virulence and pathogenicity.The S is divided with S1 and S2 region,and the S1 contains the receptor-binding domain(RBD),while the S2 contains the hydrophobic fusion domain for the entry into the host cell.Numerous host proteases have been implicated in the activation of SARS-CoV-2 S through various c leavage sites.In this article,we review host proteases including furin,trypsin,transmembrane protease serine 2(TMPRSS2)and cathepsins in the activation of SARS-CoV-2 S.Many betacoronaviruses including SARS-CoV-2 have polybasic residues at the S1/S2 site which is subjected to the cleavage by furin.The S1/S2 cleavage facilitates more assessable RBD to the receptor ACE2,and the binding triggers further conformational changes and exposure of the S2'site to proteases such as type Il transmembrane serine proteases(TTPRs)including TMPRSS2.In the presence of TMPRSS2 on the target cells,SARS-CoV-2 can utilize a direct entry route by fusion of the viral envelope to the cellular membrane.In the absence of TMPRSS2,SARS-CoV-2 enter target cells via endosomes where multiple cathepsins cleave the S for the successful entry.Additional host proteases involved in the cleavage of the S were discussed.This article also includes roles of 3C-like protease inhibitors which have inhibitory activity against cathepsin L in the entry of SARS-CoV-2,and discussed the dual roles of such inhibitors in virus replication.展开更多
AIM: To evaluate the antiviral potency of a new antihepatitis C virus(HCV) antiviral agent targeting the cellular autophagy machinery. METHODS: Non-infected liver slices, obtained from human liver resection and cut in...AIM: To evaluate the antiviral potency of a new antihepatitis C virus(HCV) antiviral agent targeting the cellular autophagy machinery. METHODS: Non-infected liver slices, obtained from human liver resection and cut in 350 μm-thick slices(2.7 × 106 cells per slice) were infected with cell culture-grown HCV Con1b/C3 supernatant(multiplicity of infection = 0.1) cultivated for up to ten days. HCV infected slices were treated at day 4 post-infection with GNS-396 for 6 d at different concentrations. HCV replication was evaluated by strand-specific real-time quantitative reverse transcription- polymerase chain reaction. The infectivity titers of supernatants were evaluated by foci formation upon inoculation into naive Huh-7.5.1 cells. The cytotoxic effect of the drugs was evaluated by lactate dehydrogenase leakage assays. RESULTS: The antiviral efficacy of a new antiviral drug, GNS-396, an autophagy inhibitor, on HCV infection of adult human liver slices was evidenced in a dosedependent manner. At day 6 post-treatment, GNS-396 EC50 was 158 nmol/L without cytotoxic effect(compared to hydroxychloroquine EC50 = 1.17 μmol/L).CONCLUSION: Our results demonstrated that our ex vivo model is efficient for evaluation the potency of autophagy inhibitors, in particular a new quinoline derivative GNS-396 as antiviral could inhibit HCV infection in a dosedependent manner without cytotoxic effect.展开更多
Single-cell RNA sequencing(scRNA-seq)has allowed for the profiling of host and virus transcripts and host-virus interactions at single-cell resolution.This review summarizes the existing scRNA-seq technologies togethe...Single-cell RNA sequencing(scRNA-seq)has allowed for the profiling of host and virus transcripts and host-virus interactions at single-cell resolution.This review summarizes the existing scRNA-seq technologies together with their strengths and weaknesses.The applications of scRNA-seq in various virological studies are discussed in depth,which broaden the understanding of the immune atlas,host-virus interactions,and immune repertoire.scRNA-seq can be widely used for virology in the near future to better understand the pathogenic mechanisms and discover more effective therapeutic strategies.展开更多
Rice sheath blight, caused by Rhizoctonia solani AG1-IA, is a major disease in rice-growing areas worldwide. Effectors of phytopathogenic fungi play important roles during the infection process of fungal pathogens ont...Rice sheath blight, caused by Rhizoctonia solani AG1-IA, is a major disease in rice-growing areas worldwide. Effectors of phytopathogenic fungi play important roles during the infection process of fungal pathogens onto their host plants. However, the molecular mechanisms by which R. solani effectors regulate rice immunity are not well understood. Through prediction, 78 candidate effector molecules were identified. Using the tobacco rattle virus-host induced gene silencing(TRV-HIGS) system, 45 RNAi constructs of effector genes were infiltrated into Nicotiana benthamiana leaves. The results revealed that eight of these constructs resulted in a significant reduction in necrosis caused by infection with the AG1-IA strain GD-118. Additionally, stable rice transformants carrying the double-stranded RNA construct for one of the effector genes, AGLIP1, were generated to further verify the function of this gene. The suppression of the AGLIP1 gene increased the resistance of both N. benthamiana and rice against GD-118, and also affected the growth rate of GD-118, indicating that AGLIP1 is a key pathogenic factor. Small RNA sequencing showed that the HIGS vectors were processed into si RNAs within the plants and then translocated to the fungi, leading to the silencing of the target genes. As a result, AGLIP1 might be an excellent candidate for HIGS, thereby enhancing crop resistance against the pathogen and contributing to the control of R. solani infection.展开更多
Hepatitis C is recognized as a major threat to global public health. The current treatment of patients with chronic hepatitis C is the addition of ribavirin to interferon-based therapy which has limited efficacy, poor...Hepatitis C is recognized as a major threat to global public health. The current treatment of patients with chronic hepatitis C is the addition of ribavirin to interferon-based therapy which has limited efficacy, poor tolerability, and significant expense. New treatment options that are more potent and less toxic are much needed. Moreover, more effective treatment is an urgent priority for those who relapse or do not respond to current regimens. A major obstacle in combating hepatitis C virus （HCV） infection is that the fidelity of the viral replication machinery is notoriously low, thus enabling the virus to quickly develop mutations that resist compounds targeting viral enzymes. Therefore, an approach targeting the host cofactors, which are indispensable for the propagation of viruses, may be an ideal target for the development of antiviral agents because they have a lower rate of mutation than that of the viral genome, as long as they have no side effects to patients. Drugs targeting, for example, receptors of viral entry, host metabolism or nuclear receptors, which are factors required to complete the HCV life cycle, may be more effective in combating the viral infection. Targeting host cofactors of the HCV life cycle is an attractive concept because it imposes a higher genetic barrier for resistance than direct antiviral compounds. However the principle drawback of this strategy is the greater potential for cellular toxicity.展开更多
基金supported by grants from the National Natural Science Foundation of China (31430091, 31772890)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA08030202)
文摘Aquatic viruses include infected viruses in aquatic animals, plants and microorganisms, and free-floating viruses(virioplankton)in water environments. In the last three decades, a huge number of aquatic viruses, especially diverse free-floating viruses,including cyanophages, phycoviruses, archaea viruses, giant viruses, and even virophages, have been identified by virological experiments and metagenomic analyses. Based on a comprehensive introduction of aquatic virus classification and their morphological and genetic diversity, here, we summarize and outline main virus species, their evolutionary contribution to aquatic communities through horizontal gene transfer, and their ecological roles for cyanobacterial bloom termination and global biogeochemical cycling in freshwater and marine ecosystems. Thereby, some novel insights of aquatic viruses and virus-host interactions, especially their evolutionary contribution and ecological rolesin diverse aquatic communities and ecosystems, are highlighted in this review.
文摘Hepatitis B virus (HBV) infection,a major public health problem,causes acute and chronic hepatitis that is often complicated by liver cirrhosis and hepatocellular carcinoma.The pathogenic mechanisms of HBV-related liver disease are not well understood,and the current licensed therapies are not effective in permanently clearing virus from the circulation.In recent years,the role of micro-ribonucleic acids (miRNAs) in HBV infection has attracted great interest.Cellular miRNAs can influence HBV replication directly by binding to HBV transcripts and indirectly by targeting cellular factors relevant to the HBV life cycle.They are also involved in the regulation of cellular genes and signaling pathways that have critical roles in HBV pathogenesis.HBV infection,in turn,can trigger changes in cellular miRNA expression that are associated with distinctive miRNA expression profiles depending on the phase of liver disease.These alterations in miRNA expression have been linked to disease progression and hepatocarcinogenesis.We provide here an up to date review regarding the field of miRNAs and HBV interplay and highlight the potential utility of miRNAs as diagnostic biomarkers and therapeutic targets for the management of HBV-related liver disease.
文摘The majority of individuals exposed to hepatitis C virus(HCV) establish a persistent infection,which is a leading cause of chronic liver disease,cirrhosis and hepatocellular carcinoma.Major progress has been made during the past twenty-five years in understanding the HCV life cycle and immune responses against HCV infection.Increasing evidence indicates that host genetic factors can significantly influence the outcome of HCV infection and the response to interferon alpha-based antiviral therapy.The arrival of highly effective and convenient treatment regimens for patients chronically infected with HCV has improved prospects for the eradication of HCV worldwide.Clinical trials are evaluating the best anti-viral drug combination,treatment doses and duration.The new treatments are better-tolerated and have shown success rates of more than 95%.However,the recent breakthrough in HCV treatment raises new questions and challenges,including the identification of HCVinfected patients and to link them to appropriate health care,the high pricing of HCV drugs,the emergence of drug resistance or naturally occurring polymorphism in HCV sequences which can compromise HCV treatment response.Finally,we still do not have a vaccine against HCV.In this concise review,we will highlight the progress made in understanding HCV infection and therapy.We will focus on the most significant unsolved problems and the key future challenges in the management of HCV infection.
基金Supported by National Natural Science Foundation of China,No.91029714,No.31071191,No.31270818 and No.31101000Natural Science Foundation of Tianjin,No.09JCZDJC17500 and No.12JCZDJC25100
文摘MicroRNAs(miRNAs) are a class of small noncoding RNAs that post-transcriptionally regulate the expression of many target genes via mRNA degradation or translation inhibition. Many studies have shown that miRNAs are involved in the modulation of gene expression and replication of hepatitis B virus(HBV) and hepatitis C virus(HCV) and play a pivotal role in host-virus interactions. Increasing evidence also demonstrates that viral infection leads to alteration of the miRNA expression profile in hepatic tissues or circulation. The deregulated miRNAs participate in hepatocellular carcinoma(HCC)initiation and progression by functioning as oncogenes or tumor suppressor genes by targeting various genes involved in cancer-related signaling pathways. The distinct expression pattern of miRNAs may be a useful marker for the diagnosis and prognosis of virus-related diseases considering the limitation of currently used biomarkers. Moreover, the role of deregulated miRNA in host-virus interactions and HCC development suggested that miRNAs may serve as therapeutic targets or astools. In this review, we summarize the recent findings about the deregulation and the role of miRNAs during HBV/HCV infection and HCC development, and we discuss the possible mechanism of action of miRNAs in the pathogenesis of virus-related diseases. Furthermore, we discuss the potential of using miRNAs as markers for diagnosis and prognosis as well as therapeutic targets and drugs.
文摘引起乙型肝炎病毒(hepatitis B virus,HBV)感染后慢性化的因素有宿主因素和病毒因素。宿主因素主要有免疫功能、细胞凋亡蛋白抑制因子(cellular inhibitor of apoptosis proteins,c IAPs)以及HLA基因多态性等使宿主不能产生有效的抗病毒反应;病毒因素主要包括乙肝病毒基因型、乙肝病毒变异、乙肝病毒抗原等,导致HBV持续存在肝细胞中不能被清除。本文综合最新国内外进展对乙肝病毒感染后慢性化的发生机制进行综述。
文摘甲型流感病毒(influenza A virus,IAV)严重威胁人类健康。病毒核心是核糖核蛋白复合物(viral ribonucleoprotein complexes,vRNPs),是病毒基因组转录和复制的最小功能单位。核蛋白(nucleoprotein,NP)是vRNP的重要组成部分之一,在流感病毒整个生命周期起着关键作用。机体存在多种宿主因子通过NP影响病毒增殖。本文就通过NP影响vRNP核输入、病毒基因组转录和复制、vRNP核输出以及vRNP组装这几个方面的宿主因子进行综述,以期为治疗IAV新靶点的发现及新药物的研发提供参考。
基金Supported by The National Natural Science Foundation of China,No. 8127181012-5 state S and T Projects for infectious diseases,No. 2012ZX10002-007+1 种基金Doctoral Fund of Ministry of Education of China,No. 20120101110009the National Basic Research Program,No. 2013CB531405
文摘Hepatitis B virus(HBV)infection is a global public health problem that causes persistent liver diseases such as chronic hepatitis,cirrhosis,and hepatocellular carcinoma.A large amount of people die annually from HBV infection.However,the pathogenesises of the HBV-related diseases are ill defined and the therapeutic strategies for the diseases are less than optimum.The recently discovered microRNAs(miRNAs)are tiny noncoding RNAs that regulate gene expression primarily at the post-transcriptional level by binding to mRNAs.miRNAs contribute to a variety of physiological and pathological processes.A number of miRNAs have been found to play a pivotal role in the host-virus interaction including host-HBV interaction.Numerous studies have indicated that HBV infection could change the cellular miRNA expression patterns and different stages of HBV associated disease have displayed distinctive miRNA profiles.Furthermore,the differential expressed miRNAs have been found involved in the progression of HBV-related diseases,for instance some miRNAs are involved in liver tumorigenesis and tumor metastasis.Studies have also shown that the circulating miRNA in serum or plasma might be a very useful biomarker for the diagnosis and prognosis of HBV-related diseases.In addition,miRNA-based therapy strategies have attracted increasing attention,indicating a promising future in the treatment of HBV-related diseases.
文摘During virus infection, viral RNAs and mRNAs function as blueprints for viral protein synthesis and possibly as pathogen-associated molecular patterns （PAMPs） in innate immunity. Here, considering recent research progress in microRNAs （miRNAs） and competitive endogenous RNAs （ceRNAs）, we speculate that viral RNAs act as sponges and can sequester endogenous miRNAs within infected cells, thus cross-regulating the stability and translational efficiency of host mRNAs with shared miRNA response elements. This cross-talk and these reciprocal interactions between viral RNAs and host mRNAs are termed ＂competitive viral and host RNAs＂ （cvhRNAs）. We further provide recent experimental evidence for the existence of cvhRNAs networks in hepatitis B virus （HBV）, as well as Her- pesvirus saimiri （HVS）, lytic murine cytomegalovirus （MCMV） and human cytomegalovirus （HCMV） infec- tions. In addition, the cvhRNA hypothesis also pre- dicts possible cross-regulation between host and other viruses, such as hepatitis C virus （HCV）, HIV, influenza virus, human papillomaviruses （HPV）. Since the interaction between miRNAs and viral RNAs also inevitably leads to repression of viral RNA function, we speculate that virus may evolve either to employ cvhRNA networks or to avoid miRNA targeting for optimal fitness within the host. CvhRNA networks may therefore play a fundamental role in the regulation of viral replication, infection establishment, and viral pathogenesis.
基金Supported by Grants from the Ministry of Education of Singapore,Academic Research Fund Tier 1 Grant R-182-000-170-112
文摘The current therapeutic regimen to combat chronic hepatitis C is not optimal due to substantial side effects and the failure of a significant proportion of patients to achieve a sustained virological response. Recently developed direct-acting antivirals targeting hepatitis C virus (HCV) enzymes reportedly increase the virologic response to therapy but may lead to a selection of drug-resistant variants. Besides direct-acting antivirals, another promising class of HCV drugs in development include host targeting agents that are responsible for interfering with the host factors crucial for the viral life cycle. A family of host proteins known as DEAD-box RNA helicases, characterized by nine conserved motifs, is known to play an important role in RNA metabolism. Several members of this family such as DDX3, DDX5 and DDX6 have been shown to play a role in HCV replication and this review will summarize our current knowledge on their interaction with HCV. As chronic hepatitis C is one of the leading causes of hepatocellular carcinoma, the involvement of DEAD-box RNA helicases in the development of HCC will also be highlighted. Continuing research on the interaction of host DEAD-box proteins with HCV and the contribution to viral replication and pathogenesis could be the panacea for the development of novel therapeutics against HCV.
基金Supported by Research Grants from National S and T Major Project for Infectious Diseases Control,No.2012ZX10002003-004-010National Natural Science Foundation of China,No.81171564,No.81273557 and No.81302812+2 种基金Medical Youth Science Program,No.13QNP100Shanghai Municipal Natural Science Foundation,No.13ZR1449300Shanghai LAD Project,No.B901
文摘Hepatitis C virus(HCV)infection is a global health problem,with an estimated 170 million people being chronically infected.HCV cell entry is a complex multi-step process,involving several cellular factors that trigger virus uptake into the hepatocytes.The high-density lipoprotein receptor scavenger receptor class B type I,tetraspanin CD81,tight junction protein claudin-1,and occludin are the main receptors that mediate the initial step of HCV infection.In addition,the virus uses cell receptor tyrosine kinases as entry regulators,such as epidermal growth factor receptor and ephrin receptor A2.This review summarizes the current understanding about how cell surface molecules are involved in HCV attachment,internalization,and membrane fusion,and how host cell kinases regulate virus entry.The advances of the potential antiviral agents targeting this process are introduced.
基金supported by the grants from the National Natural Science Foundation of China (31720103912 and 31801704)the ’Taishan Scholar’ Construction Project, China (TS201712023)。
文摘Tomato brown rugose fruit virus(ToBRFV) is a novel tobamovirus firstly reported in 2015 and poses a severe threat to the tomato industry. So far, it has spread to 10 countries in America, Asia, and Europe. In 2019, ToBRFV was identified in Shandong Province(ToBRFV-SD), China. In this study, it was shown that ToBRFV-SD induced mild to severe mosaic and blistering on leaves, necrosis on sepals and pedicles, and deformation, yellow spots, and brown rugose necrotic lesions on fruits. ToBRFV-SD induced distinct symptoms on plants of tomato, Capsicum annumm, and Nicotiana benthamiana, and caused latent infection on plants of Solanum tuberosum, Solanum melongena, and N. tabacum cv. Zhongyan 102. All the 50 tomato cultivars tested were highly sensitive to ToBRFV-SD. The complete genomic sequence of ToBRFV-SD shared the highest nucleotide and amino acid identities with isolate IL from Israel. In the phylogenetic tree constructed with the complete genomic sequence, all the ToBRFV isolates were clustered together and formed a sister branch with tobacco mosaic virus(TMV). Furthermore, a quadruplex RT-PCR system was developed that could differentiate ToBRFV from other economically important viruses affecting tomatoes, such as TMV, tomato mosaic virus, and tomato spotted wilt virus. The findings of this study enhance our understanding of the biological and molecular characteristics of ToBRFV and provide an efficient and effective detection method for multiple infections, which is helpful in the management of ToBRFV.
基金supported by grants from the National Natural Science Foundation of China(31900146)the key Biosafety Science and Technology Program of Hubei Jiangxia Laboratory(JXBS001)+1 种基金the Hubei Natural Science Foundation for Distinguished Young Scholars(2021CFA050)the Creative Research Group Program of Natural Science Foundation of Hubei Province(2022CFA021).
文摘Severe fever with thrombocytopenia syndrome(SFTS)caused by the SFTS virus(SFTSV)is an emerging disease in East Asia with a fatality rate of up to 30%.However,the viral-host interaction of SFTSV remains largely unknown.The heat-shock protein 90(Hsp90)family consists of highly conserved chaperones that fold and remodel proteins and has a broad impact on the infection of many viruses.Here,we showed that Hsp90 is an important host factor involved in SFTSV infection.Hsp90 inhibitors significantly reduced SFTSV replication,viral protein expression,and the formation of inclusion bodies consisting of nonstructural proteins(NSs).Among viral proteins,NSs appeared to be the most reduced when Hsp90 inhibitors were used,and further analysis showed that their translation was affected.Co-immunoprecipitation of NSs with four isomers of Hsp90 showed that Hsp90βspecifically interacted with them.Knockdown of Hsp90βexpression also inhibited replication of SFTSV.These results suggest that Hsp90βplays a critical role during SFTSV infection and could be a potential target for the development of drugs against SFTS.
基金supported by the National Natural Science Foundation of China(82071788,81901598,81771704,and 82041015)National Key R&D Program of China(2022YFC2604100).
文摘Influenza A virus(IAV),responsible for seasonal epidemics and recurring pandemics,represents a global threat to public health.Given the risk of a potential IAV pandemic,it is increasingly important to better understand virushost interactions and develop new anti-viral strategies.Here,we reported nonmuscle myosin IIA(MYH9)-mediated regulation of IAV infection.MYH9 depletion caused a profound inhibition of IAV infection by reducing viral attachment and internalization in human lung epithelial cells.Surprisingly,overexpression of MYH9 also led to a significant reduction in viral productive infection.Interestingly,overexpression of MYH9 retained viral attachment,internalization,or uncoating,but suppressed the viral ribonucleoprotein(vRNP)activity in a minigenome system.Further analyses found that excess MYH9 might interrupt the formation of vRNP by interacting with the viral nucleoprotein(NP)and result in the reduction of the completed vRNP in the nucleus,thereby inhibiting subsequent viral RNA transcription and replication.Together,we discovered that MYH9 can interact with IAV NP protein and engage in the regulation of vRNP complexes,thereby involving viral replication.These findings enlighten new mechanistic insights into the complicated interface of host-IAV interactions,ultimately making it an attractive target for the generation of antiviral drugs.
基金National Institutes of Health(NIH)(grants R01 A/130092 and Al161085).
文摘The spike protein(S)of SARS-CoV-2 is responsible for viral attachment and entry,thus a major factor for host suscep-tibility,tissue tropism,virulence and pathogenicity.The S is divided with S1 and S2 region,and the S1 contains the receptor-binding domain(RBD),while the S2 contains the hydrophobic fusion domain for the entry into the host cell.Numerous host proteases have been implicated in the activation of SARS-CoV-2 S through various c leavage sites.In this article,we review host proteases including furin,trypsin,transmembrane protease serine 2(TMPRSS2)and cathepsins in the activation of SARS-CoV-2 S.Many betacoronaviruses including SARS-CoV-2 have polybasic residues at the S1/S2 site which is subjected to the cleavage by furin.The S1/S2 cleavage facilitates more assessable RBD to the receptor ACE2,and the binding triggers further conformational changes and exposure of the S2'site to proteases such as type Il transmembrane serine proteases(TTPRs)including TMPRSS2.In the presence of TMPRSS2 on the target cells,SARS-CoV-2 can utilize a direct entry route by fusion of the viral envelope to the cellular membrane.In the absence of TMPRSS2,SARS-CoV-2 enter target cells via endosomes where multiple cathepsins cleave the S for the successful entry.Additional host proteases involved in the cleavage of the S were discussed.This article also includes roles of 3C-like protease inhibitors which have inhibitory activity against cathepsin L in the entry of SARS-CoV-2,and discussed the dual roles of such inhibitors in virus replication.
基金Supported by The Institut National de la Sante et de la Recherche Medicale(INSERM,France)the personal support of Professor Jean-Francois Delfraissy as Director of the French Agency,Agence Nationale de Recherches sur le Sida et les hepatites virales(ANRS)
文摘AIM: To evaluate the antiviral potency of a new antihepatitis C virus(HCV) antiviral agent targeting the cellular autophagy machinery. METHODS: Non-infected liver slices, obtained from human liver resection and cut in 350 μm-thick slices(2.7 × 106 cells per slice) were infected with cell culture-grown HCV Con1b/C3 supernatant(multiplicity of infection = 0.1) cultivated for up to ten days. HCV infected slices were treated at day 4 post-infection with GNS-396 for 6 d at different concentrations. HCV replication was evaluated by strand-specific real-time quantitative reverse transcription- polymerase chain reaction. The infectivity titers of supernatants were evaluated by foci formation upon inoculation into naive Huh-7.5.1 cells. The cytotoxic effect of the drugs was evaluated by lactate dehydrogenase leakage assays. RESULTS: The antiviral efficacy of a new antiviral drug, GNS-396, an autophagy inhibitor, on HCV infection of adult human liver slices was evidenced in a dosedependent manner. At day 6 post-treatment, GNS-396 EC50 was 158 nmol/L without cytotoxic effect(compared to hydroxychloroquine EC50 = 1.17 μmol/L).CONCLUSION: Our results demonstrated that our ex vivo model is efficient for evaluation the potency of autophagy inhibitors, in particular a new quinoline derivative GNS-396 as antiviral could inhibit HCV infection in a dosedependent manner without cytotoxic effect.
基金supported by the National Key Research and Devel-opment Program of China(2021YFC2300202)the National Natural Science Foundation of China(U1902210,81871641,81972979,82172266,82241071,and 81902048)+1 种基金the Support Project of High-level Teachers in Beijing Municipal Universities in the Period of 13th Five-year Plan(IDHT20190510)the Beijing Key Laboratory of Emerging In-fectious Diseases(DTKF202103).
文摘Single-cell RNA sequencing(scRNA-seq)has allowed for the profiling of host and virus transcripts and host-virus interactions at single-cell resolution.This review summarizes the existing scRNA-seq technologies together with their strengths and weaknesses.The applications of scRNA-seq in various virological studies are discussed in depth,which broaden the understanding of the immune atlas,host-virus interactions,and immune repertoire.scRNA-seq can be widely used for virology in the near future to better understand the pathogenic mechanisms and discover more effective therapeutic strategies.
基金supported by the Henan Province Science and Technology Research Project, China (Grant No. 242102110232)the National Natural Science Foundation of China (Grant No. 31801677)the Major Program of Guangdong Basic and Applied Basic Research, China (Grant No. 2019B030302006)。
文摘Rice sheath blight, caused by Rhizoctonia solani AG1-IA, is a major disease in rice-growing areas worldwide. Effectors of phytopathogenic fungi play important roles during the infection process of fungal pathogens onto their host plants. However, the molecular mechanisms by which R. solani effectors regulate rice immunity are not well understood. Through prediction, 78 candidate effector molecules were identified. Using the tobacco rattle virus-host induced gene silencing(TRV-HIGS) system, 45 RNAi constructs of effector genes were infiltrated into Nicotiana benthamiana leaves. The results revealed that eight of these constructs resulted in a significant reduction in necrosis caused by infection with the AG1-IA strain GD-118. Additionally, stable rice transformants carrying the double-stranded RNA construct for one of the effector genes, AGLIP1, were generated to further verify the function of this gene. The suppression of the AGLIP1 gene increased the resistance of both N. benthamiana and rice against GD-118, and also affected the growth rate of GD-118, indicating that AGLIP1 is a key pathogenic factor. Small RNA sequencing showed that the HIGS vectors were processed into si RNAs within the plants and then translocated to the fungi, leading to the silencing of the target genes. As a result, AGLIP1 might be an excellent candidate for HIGS, thereby enhancing crop resistance against the pathogen and contributing to the control of R. solani infection.
文摘Hepatitis C is recognized as a major threat to global public health. The current treatment of patients with chronic hepatitis C is the addition of ribavirin to interferon-based therapy which has limited efficacy, poor tolerability, and significant expense. New treatment options that are more potent and less toxic are much needed. Moreover, more effective treatment is an urgent priority for those who relapse or do not respond to current regimens. A major obstacle in combating hepatitis C virus （HCV） infection is that the fidelity of the viral replication machinery is notoriously low, thus enabling the virus to quickly develop mutations that resist compounds targeting viral enzymes. Therefore, an approach targeting the host cofactors, which are indispensable for the propagation of viruses, may be an ideal target for the development of antiviral agents because they have a lower rate of mutation than that of the viral genome, as long as they have no side effects to patients. Drugs targeting, for example, receptors of viral entry, host metabolism or nuclear receptors, which are factors required to complete the HCV life cycle, may be more effective in combating the viral infection. Targeting host cofactors of the HCV life cycle is an attractive concept because it imposes a higher genetic barrier for resistance than direct antiviral compounds. However the principle drawback of this strategy is the greater potential for cellular toxicity.
