Pathogenesis and clinical features of severe hepatitis E virus infection

The hepatitis E virus(HEV),a member of the Hepeviridae family,is a small,non-enveloped icosahedral virus divided into eight distinct genotypes(HEV-1 to HEV-8).Only genotypes 1 to 4 are known to cause diseases in humans.Genotypes 1 and 2 commonly spread via fecal-oral transmission,often through the consum-ption of contaminated water.Genotypes 3 and 4 are known to infect pigs,deer,and wild boars,often transferring to humans through inadequately cooked meat.Acute hepatitis caused by HEV in healthy individuals is mostly asymptomatic or associated with minor symptoms,such as jaundice.However,in immunosup-pressed individuals,the disease can progress to chronic hepatitis and even escalate to cirrhosis.For pregnant women,an HEV infection can cause fulminant liver failure,with a potential mortality rate of 25%.Mortality rates also rise amongst cirrhotic patients when they contract an acute HEV infection,which can even trigger acute-on-chronic liver failure if layered onto pre-existing chronic liver disease.As the prevalence of HEV infection continues to rise worldwide,highlighting the particular risks associated with severe HEV infection is of major medical interest.This text offers a brief summary of the characteristics of hepatitis developed by patient groups at an elevated risk of severe HEV infection.

MicroRNA-185-5p mediates regulation of SREBP2 expression by hepatitis C virus core protein

AIM: To investigate the molecular mechanism for regulation of cholesterol metabolism by hepatitis C virus(HCV) core protein in Hep G2 cells.METHODS: HCV genotype 1b core protein was cloned and expressed in Hep G2 cells. The cholesterol content was determined after transfection. The expression of sterol regulatory element binding protein 2(SREBP2) and the rate-limiting enzyme in cholesterol synthesis(HMGCR) was measured by quantitative real-time PCR and immunoblotting after transfection. The effects of core protein on the SREBP2 promoter and 3'-untranslated region were analyzed by luciferase assay. We used different target predictive algorithms, micro RNA(mi RNA) mimics/inhibitors, and site-directed mutation to identify a putative target of a particular mi RNA.RESULTS: HCV core protein expression in Hep G2 cells increased the total intracellular cholesterol level(4.05 ± 0.17 vs 6.47 ± 0.68, P = 0.001), and this increase corresponded to an increase in SREBP2 and HMGCR m RNA levels(P = 0.009 and 0.037, respectively) and protein expression. The molecular mechanism studyrevealed that the HCV core protein increased the expression of SREBP2 by enhancing its promoter activity(P = 0.004). In addition, mi R-185-5p expression was tightly regulated by the HCV core protein(P = 0.041). Moreover, overexpression of mi R-185-5p repressed the SREBP2 m RNA level(P = 0.022) and protein expression. In contrast, inhibition of mi R-185-5p caused upregulation of SREBP2 protein expression. mi R-185-5p was involved in the regulation of SREBP2 expression by HCV core protein. CONCLUSION: HCV core protein disturbs the cholesterol homeostasis in Hep G2 cells via the SREBP2 pathway; mi R-185-5p is involved in the regulation of SREBP2 by the core protein.

Cross-neutralizing Anti-hemagglutinin Antibodies Isolated from Patients Infected with Avian Influenza A(H5N1) Virus

Objective To recover broad-neutralizing monoclonal antibodies(Bn Abs)from avian influenza A(H5N1)virus infection cases and investigate their genetic and functional features.Methods We screened the Abs repertoires of expanded B cells circulating in the peripheral blood of H5N1 patients.The genetic basis,biological functions,and epitopes of the obtained Bn Abs were assessed and modeled.Results Two Bn Abs,2-12 D5,and 3-37 G7.1,were respectively obtained from two human H5N1 cases on days 12 and 21 after disease onset.Both Abs demonstrated cross-neutralizing and Ab-dependent cellular cytotoxicity(ADCC)activity.Albeit derived from distinct Ab lineages,i.e.,V^H1-69-D2-15-JH^4(2-12D5)and V^H1-2-D3-9-JH^5(3-32 G7.1),the Bn Abs were directed toward CR6261-like epitopes in the HA stem,and HA2 I45 in the hydrophobic pocket was the critical residue for their binding.Signature motifs for binding with the HA stem,namely,IFY in VH1-69-encoded Abs and LXYFXW in D3-9-encoded Abs,were also observed in 2-12D5 and 3-32 G7.1,respectively.Conclusions Cross-reactive B cells of different germline origins could be activated and re-circulated by avian influenza virus.The HA stem epitopes targeted by the Bn Abs,and the two Ab-encoding genes usage implied the VH1-69 and D3-9 are the ideal candidates triggered by influenza virus for vaccine development.

Hepatitis C virus core protein-induced miR-93-5p upregulation inhibits interferon signaling pathway by targeting IFNAR1

AIM To investigate the mechanism by which hepatitis C virus(HCV) core protein-induced mi R-93-5 p up-regulation regulates the interferon(IFN) signaling pathway.METHODS HCV-1 b core protein was exogenously expressed in Huh7 cells using pc DNA3.1(+) vector. The expression of mi R-93-5 p and interferon receptor 1(IFNAR1) was measured using quantitative reverse transcriptionpolymerase chain reaction and Western blot. The protein expression and phosphorylation level of STAT1 were evaluated by Western blot. The overexpression and silencing of mi R-93-5 p and IFNAR1 were performed using mi R-93-5 p agomir and antagomir, and pc DNA3.1-IFNAR1 and IFNAR1 si RNA, respectively. Luciferase assay was used to identify whether IFNAR1 is a target of mi R-93-5 p. Cellular experiments were also conducted.RESULTS Serum mi R-93-5 p level was increased in patients with HCV-1 b infection and decreased to normal level after HCV-1 b clearance, but persistently increased in those with pegylated interferon-α resistance, compared with healthy subjects. Serum mi R-93-5 p expression had an AUC value of 0.8359 in distinguishing patients with pegylated interferon-α resistance from those with pegylated interferon-α sensitivity. HCV-1 b core protein increased mi R-93-5 p expression and induced inactivation of the IFN signaling pathway in Huh7 cells. Furthermore, IFNAR1 was identified as a direct target of mi R-93-5 p, and IFNAR1 restore could rescue mi R-93-5 p-reduced STAT1 phosphorylation, suggesting that the mi R-93-5 p-IFNAR1 axis regulates the IFN signaling pathway.CONCLUSION HCV-1 b core protein-induced mi R-93-5 p up-regulation inhibits the IFN signaling pathway by directly targeting IFNAR1, and the mi R-93-5 p-IFNAR1 axis regulates STAT1 phosphorylation. This axis may be a potential therapeutic target for HCV-1 b infection.

Virus-phytoplankton adhesion:a new WSSV transmission route to zooplankton

The pathogenicity of white spot syndrome virus （WSSV） to zooplankton species, rotifer Brachionus urceus （Linnaeus）, copepod Acartia clausi （Giesbrecht） and mysid shrimp Neomysis awatschensis （ Brandt ）, was estimated by immersion challenge and virus - phytoplankton adhesion mute to investigate a potential new transmission mute of WSSV to zooplankton. WSSV succeeded in infecting these zooplankton species and nested-PCR revealed positive results for the virus - phytoplankton adhesion mute, whereas WSSV cannot infect zooplankton by immersion challenge. These results indicated that virus - phytoplankton adhesion route is a successful new transmission mute of WSSV to zooplankton and also implied that phytoplankton could be a carrier in WSSV transmission.

(-)-Epigallocatechin-3-gallate enhances poly I:C-induced interferon-λ1 production and inhibits hepatitis C virus replication in hepatocytes

AIM To investigate the effect of(-)-epigallocatechin-3-gallate(EGCG) on polyinosinic-polycytidylic acid(poly I:C)-triggered intracellular innate immunity against hepatitis C virus(HCV) in hepatocytes. METHODS A cell culture model of HCV infection was generated by infecting a hepatoma cell line, Huh7, with HCV JFH-1 strain(JFH-1-Huh7). Poly I:C with a high molecular weight and EGCG were used to stimulate the JFH-1-Huh7 cells. Real-time reverse transcription-polymerase chain reaction was used to detect the expression levels of intracellular m RNAs and of intracellular and extracellular HCV RNA. Enzyme-linked immunosorbent assay was used to evaluate the interferon(IFN)-λ1 protein level in the cell culture supernatant. Immunostaining was used to examine HCV core protein expression in Huh7 cells.RESULTS Our recent study showed that HCV replication could impair poly I:C-triggered intracellular innate immune responses in hepatocytes. In the current study, we showed that EGCG treatment significantly increased the poly I:C-induced expression of Toll-like receptor 3(TLR3), retinoic acid-inducible gene I, and IFN-λ1 in JFH-1-Huh7 cells. In addition, supplementation with EGCG increased the poly I:C-mediated antiviral activity in JFH-1-Huh7 cells at the intracellular and extracellular HCV RNA and protein levels. Further investigation of the mechanisms showed that EGCG treatment significantly enhanced the poly I:C-induced expression of IFN-regulatory factor 9 and several antiviral IFNstimulated genes, including ISG15, ISG56, myxovirus resistance A, and 2'-5'-oligoadenylate synthetase 1, which encode the key antiviral elements in the IFN signaling pathway. CONCLUSION Our observations provide experimental evidence that EGCG has the ability to enhance poly I:C-induced intracellular antiviral innate immunity against HCV replication in hepatocytes.

African swine fever virus MGF505-3R inhibits cGAS-STING-mediated IFN-βpathway activation by degrading TBK1

African swine fever virus(ASFV)is an important pathogen causing acute infectious disease in domestic pigs and wild boars that seriously endangers the global swine industry.As ASFV is structurally complex and encodes a large number of functional proteins,no effective vaccine has been developed to date.Thus,dissecting the mechanisms of immune escape induced by ASFV proteins is crucial.A previous study showed that the ASFV-encoded protein is an important factor in host immunity.In this study,we identified a negative regulator,MGF505-3R,that significantly downregulated cGAS/STING-and poly(dG:dC)-mediated IFN-βand interferon stimulation response element(ISRE)reporter activity and suppressed IFNB1 and IFIT2 mRNA levels.In addition,TBK1,IRF3 and IκBαphosphorylation levels were also inhibited.Mechanistically,MGF505-3R interacted with cGAS/TBK1/IRF3 and targeted TBK1 for degradation,thereby disrupting the cGAS-STING-mediated IFN-βsignaling pathway,which appears to be highly correlated with autophagy.Knockdown MGF505-3R expression enhanced IFN-βand IL-1βproduction.Taken together,our study revealed a negative regulatory mechanism involving the MGF505-3R-cGAS-STING axis and provided insights into an evasion strategy employed by ASFV that involves autophagy and innate signaling pathways.

Elevated soluble 4-1BB is associated with serum markers of hepatitis B virus in patients with chronic hepatitis B

BACKGROUND Previous studies have suggested that the costimulatory molecule 4-1BB plays pivotal roles in regulating immunity during chronic viral infection.However,up to now,there are few studies about 4-1BB in chronic hepatitis B(CHB).AIM To clarify this issue,we report our comprehensive study results on the expression levels of 4-1BB in patients with CHB.METHODS From September 2018 to June 2019,a total of 64 patients with CHB were recruited from the Department of Hepatology,The First Hospital of Jilin University.Peripheral blood samples were collected from 52 treatment-naïve and 12 entecavir-treated patients with CHB as well as 37 healthy donors(including 24 healthy adults and 13 healthy children).The levels of soluble 4-1BB(s4-1BB)in plasma were measured by ELISA.4-1BB mRNA expression in peripheral blood mononuclear cells was detected by real-time quantitative PCR.RESULTS The s4-1BB levels in the plasma of patients with CHB were significantly higher than those in healthy adults(94.390±7.393 ng/mL vs 8.875±0.914 ng/mL,P<0.001).In addition,the s4-1BB level in plasma was significantly increased in patients with a higher viral load and a disease flare up.However,there were no significant differences between treatment-naïve and entecavir-treated patients.Interestingly,among treatment-naïve patients with CHB,the levels of s4-1BB in plasma had a significant positive correlation with hepatitis B surface antigen,hepatitis B virus DNA,hepatitis B e antigen,and triglyceride levels(r=0.748,P<0.001;r=0.406,P=0.004;r=0.356,P=0.019 and r=-0.469,P=0.007,respectively).The 4-1BB mRNA expression was higher in the peripheral blood mononuclear cells of patients with CHB than in the peripheral blood mononuclear cells of healthy adults,but the difference was not statistically significant.CONCLUSION These results suggest that the levels of s4-1BB may be associated with pathogenesis of hepatitis B virus and therefore may be a promising biomarker for disease progression.

Specific activation of 2'-5'oligoadenylate synthetase gene promoter by hepatitis C virus-core protein:A potential for developing hepatitis C virus targeting gene therapy

AIM： TO examine whether 2＇-5＇oligoadenylate synthetase （OAS） gene promoter can be specifically activated by hepatitis C virus （HCV）-core protein. METHODS： Human embryo hepatic cell line L02 was transfected with pcDNA3.1-core plasmid and selected by G418. Expression of HCV-core was detected by reverse transcription polymerase chain reaction and Western blotting. The OAS promoter sequence was amplified from the genomic DNA and inserted into pGL3-basic vector. The resultant pGL3-OAS-Luci plasmid was transiently transfected into L02/core cells and luciferase activity was assayed. I^ESULTS： L02/core cell line stably expressing HCV- core protein was established. The pGL3-OAS-Luci construct exhibited significant transcriptional activity in the L02/core cells but not in the L02 cells. CONCLUSION： HCV-core protein activates the OAS gene promoter specifically and effectively. Utilization of OAS gene promoter would be an ideal strategy for developing HCV-specific gene therapy.

Expression of co-stimulatory molecules B7-2 and PD-L1 on peripheral blood mononuclear cells in patients with chronic hepatitis B virus infection

Objective： To explore the roles of the expression of the co-stimulatory molecule, B7-2, and the co-inhibitory molecule, PD-L1, on peripheral blood mononuclear cells in the mechanism of immunotolerance in chronic hepatitis B virus infection. Methods： Thirty HBV infected patients in the immunoreactive phase and 20 patients in the immunotolerant phase were enrolled in the study, while 20 healthy volunteers were used as controls. RT- PCR and real-time PCR methods were used to detect the expression levels of B7-2 and PD-L1 mRNA in peripheral blood mononuclear cells in chronic HBV infected patients. Results： The B7-2 expression in irnrnunoreactive and immunotolerant patients was significantly lower than that in the controls （P all 〈 0.01 ）; B7-2 expression in immunoreactive patients was significantly lower than in immunotolerant patients （P 〈 0.01）. PD-L1 expression in irnmunoreactive patients and immunotolerant patients was significantly higher than that in normal controls （P all 〈 0.01）. The PD-L1/BT-2 ratios in immunoreactive and immunotolerant patients were significantly higher than that of the healthy controls （P all 〈 0.01）; the PD-L1/ B7-2 ratio was significantly higher in the immunoreactive patients than in the immunotolerant patients （P 〈 0.01）. Conclusion： In chronic HBV infection, changes in the expression of co-stimulatory and co-inhibitory molecules imply a protective adjustment against the patient＇ s immune response that may result in increased immunotolerance and persistent HBV infection.

A retrospective investigation on the phenotype and stability of the E-protein gene in Japanese Encephalitis (JE) virus strain SA14-14-2 used live-attenuated JE vaccine

To detect retrospectively the phenotype and stability of the E-protein gene in Japanese Encephalitis （JE） virus strain SA14-14-2 used in the live-attenuated JE vaccine prepears, the viral titer was titrated by plaque formation in BHK-21 cell cultures, and the neuro-virulence of viruses was assayed in mice with body weight of 12-14 g by intracerebral inoculation. Meanwhile, the total RNA of virus gene was extracted and amplified by RT-PCR with the designed primers, and then it was purified and cloned to the expression vector pGEM-T. The recombinant plasmid was purified and sequenced. It was found that the loss of viral titer of vaccines stored in -20℃ for longer than 10 years was less than 0.5 Lg PFU/ml. No mice inoculated intracerebrally showed signs of illness or even death. The size of plagues of the vaccine virus remained to be small, and the E genes of primary virus seed SA14-14-2 and the vaccines prepared at different years （1987-2001） were unchanged, in- cluding the 8 critical amino acid sites which were different from the parent wild virus strain SA14 and the related neuro-virulence. These results indicate that the genotypic and biological characteristics of the attenuated JE virus strain SA14-14-2 and its vaccines sion noted. prepared are quite stable without any reversion noted.

Cytokine responses in infants infected with respiratory syncytial virus

Introduction: Variability in severity of Respiratory Syncytial Virus (RSV) infection is reportedly due to differences in inflammatory response. Objective: To characterize the cytokine response in RSV+ infants aged 0 - 36 months and to relate their responses to disease severity. Methods: Nasopharyngeal aspirations (NPAs) were analyzed for RSV and IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-1RA, IL-4R, IFN-γ, sTNFR1, sTNFR2, and TNF-α. Clinical data were collected from the medical records. Results: We included 331 infants of whom 214 were RSV+. In comparison to RSV- infants, they had significantly higher levels of TNF-α, IL-6, IL-1β, and IFN-γ (p α, IL-6, and IL-1β. sTNFR1/2 were significantly increased in RSV+ infants. Hospitalized patients had significantly higher levels of TNF-α, sTNFR2, and IL-10 (p < 0.05) than non-hospitalized patients. The cytokine response could not be related to disease severity. We found no evidence of a skewed Th1/Th2 immune profile. Conclusion: In acute RSV disease, infected infants’ NPAs contain a significant amount of pro-inflammatory cytokines. Whether this response is beneficial or deleterious remains unanswered. Interpersonal variations in cytokine responses might be linked to an inherited tendency to variations in disease severity.

谈校园网络的安全及防范-ARP篇

随着网络世界的到来，校园网作为学校重要的基础设施，担负着学校教学、教研、管理、信息共享和对外交流等许多重要任务。校园网的安全问题，直接影响着学校的教学活动。文章结合近期校园局域网络常受ARP网络病毒攻击和侵扰，对如何加强校园网络安全作了分析和探讨。

DC-SIGN (CD209) Promoter -336 A/G Polymorphism Is Not Associated with Dengue Fever at Burkina Faso, West Africa

Objective: The aim of this study was to characterize the polymorphisms of the DC-SIGN (-336 A/G, rs4804803) gene and their association with the immunopathogenicity of dengue fever in Burkina Faso. Methods: A total of three hundred forty-one subjects, patients of all ages have been included in the study: 208 persons presenting clinical signs of dengue fever which were confirmed by diagnostic and 133 Healthy Controls. Genotyping for the CD209 variant (-336 A/G, rs4804803) was carried out using TaqMan SNP Genotyping Assays. Haplotype frequencies were inferred and compared between the study groups. Results: The percentage of men was 61.88% (211/341) and 38.12% (130/341) for women. The highest frequency of dengue fever (77.42%) was noted in patients with age between 20 to 40 years. Around 1.52% of the study population was positive for HIV, 40.55% were carriers of HBV and 3.83% of HCV. Genotype distribution of the CD209 variant (-336 A/G, rs4804803) was in Hardy-Weinberg equilibrium in both patients and controls. The frequency of allele A was higher than allele G;however, statistical analyses showed that there is no significant difference in genotypes GG, AG and AA in patients and controls. Conclusion: This related no significant association with dengue for the variant of ?336 A/G in the DC-SIGN gene in an Ouagadougou population. However, our results offered the SNP frequencies in a West African population, which might be useful for the study of ethnic groups.

Uptake of Two Doses of HPV Vaccines in Nakuru County, Kenya: A Case of Rongai and Nakuru West Sub-Counties

Background: HPV vaccines were introduced globally as one of the most effective strategies to prevent cervical cancer. HPV vaccines were rolled out in Kenya in 2019 targeting girls aged 10 - 14 years, but the uptake has not been satisfactory. The Purpose of the Study: The aim of the study was to assess the level of HPV uptake among girls aged 10 - 14 years in Rongai and Nakuru West Sub-Counties in Nakuru County. Method: This was a cross-sectional study where data on HPV uptake was retrieved from all the public health facilities located in Rongai and Nakuru West Sub-Counties, Nakuru County, entered into Microsoft Excel then transferred to SPSS version 26 for analysis of HPV vaccine uptake since the year 2019 to June 2022. Data Analysis: Descriptive statistics were used where tables and graphs were generated to represent the percentages and trends of HPV vaccine uptake. Results: The average percentage of HPV uptake in Nakuru West Sub-County since the rollout of vaccination was 17% while that of Rongai Sub-County was 15%. In 2019, HPV 1 uptake was generally low for both Sub-Counties, the results show no HPV 2 vaccines were administered during that year. In 2020, Nakuru West reported an increase in HPV 1 uptake, while Rongai reported a drop in HPV 1 uptake. Both Sub-Counties reported an increase in HPV 2 in 2020 as compared to the previous year. The highest HPV 1 & 2 uptakes were reported in 2021 in both Sub-Counties. The uptake of both HPV 1 & 2 kept increasing subsequently. Conclusion: The overall uptake of HPV vaccines for Doses 1 and 2, in both Rongai and Nakuru West Sub-Counties, is low. However, there has been a consistent increase in uptake of the two doses in the two Sub-Counties since 2019. Therefore, raising public awareness of the importance of HPV vaccination could improve uptake.

计算机实验室中的ARP病毒防治技术研究

针对高校计算机实验室网络中ARP病毒盛行严重影响教学的情况,阐述了ARP协议的工作原理、特征及攻击类型,分析了ARP协议与ARP欺骗的关系,并从多个方面提出了ARP病毒的防治技术.

ARP病毒的原理及防御方法

目的了解ARP病毒原理,有效地防御ARP病毒.方法解析ARP协议原理,分析ARP病毒机理.结果通过ARP病毒原理的分析,指出ARP病毒利用ARP协议本身的漏洞进行ARP欺骗,虚拟网关、制造垃圾数据堵塞网络,从宏观和微观两方面给出局域网内有效地防御ARP病毒的对策.结论ARP病毒是可以防御的1对付病毒最有效的方法是预防,制度、措施、法规、法律是保障,而其核心是人.

基于WinPcap的校园网ARP病毒检测防御系统设计与实现

为了解决校园网中ARP病毒泛滥,无法预防和彻底根除的难题,研究了ARP协议工作原理、存在的漏洞,由它引起的ARP病毒的攻击原理及其危害。分析了目前常见的ARP病毒防御措施,指出其不足。结合校园网实情和多年网管经验,设计并实现了一种基于WinPcap的ARP病毒的检测防御系统,能够快速捕获ARP数据包并进行检测,分析过滤后发现定位ARP病毒源,并对中毒主机及时断网,通知用户立即查杀病毒,弥补了传统方法只对局域网中正常主机在接收ARP报文时攻击欺骗进行防御,而对中毒主机束手无策的缺陷。实践证明系统达到预期设计要求,能够很好地防御校园网中ARP病毒。

图书馆局域网防ARP病毒攻击方法探讨

ARP病毒攻击在图书馆局域网中经常出现,这种病毒清理和防范比较困难,不少网络管理员对此感到困扰。在图书馆以电子阅览室受害最为明显,影响也较大,给读者和工作人员带来诸多不便。为避免或尽量减少因ARP病毒攻击造成的影响,笔者对ARP病毒的症状、攻击原理及处理办法等几个方面作了粗浅的探讨。