Hepatitis E Virus Infection Research Articles

Seroepidemiology of Asymptomatic Plasmodium falciparum CoInfections with Hepatitis B And C Virus among Blood Donors in Modakeke Area Office, Ile Ife, Osun State, Nigeria

Despite the remarkable achievements in the reduction of malaria mortality, the disease had remained the most common cause of morbidity and mortality. Infection with hepatitis B virus (HBV) and hepatitis C virus (HCV) might associate with increased mortality rate as the infections may predisposes to the development of serious liver diseases such as liver cirrhosis, liver failure and hepatocellular carcinoma (HCC). The aim of the present study was to determine the Asymptomatic Plasmodium falciparum co-infections with hepatitis B and C viruses among blood donors in Modakeke Area Office, Ile Ife, Osun State, Nigeria. The study was conducted in Modakeke Area Office, Ile Ife, Osun State. The study was conducted in Modakeke health facility, Ile Ife, Osun State. Five (5) ml of venous blood was obtained from each of 400 blood donors into plain bottles and labeled accordingly. Thick and thin films of the donor’s blood samples were made on slides dried for five minutes at 37°C then stained using Giemsa stain. The slides were then examined microscopically for presence and densities of malaria parasites. Species identification and determination of the Hematological parameters were also conducted on the slides. Sera were separated from the remaining aliquots of the blood and screened for hepatitis-B and C surface antigens (HBsAg and anti-HCV). The overall mean parasitaemia of malarious blood donors was 786.20µl/blood while that of blood donors with hepatitis virus infection was 53 representing 13.3% of the total donor examined. Donors infected with HBV, HCV and co-infection of HBV and HCV had viraemia of 25 (6.3%), 21 (5.3%) and 7(1.8%) respectively. Among the age groups, high prevalence of Hepatitis viral infection rate of 57.9% was recorded among aged group 18-26 years. The infection rate of 15.8%, 13.6% and 10.5% of HBV, HCV was recorded from age group 18-26years respectively. The highest co-infection rate of HBV and HCV of 18.8% was recorded from age group 54-62years, while high mean malaria parasitaemia of 1,882.78 (µl of blood) was also recorded among donors aged 18-26 years. High hepatitis viral infection rate of 22.2% with 16.7% of HCV were recorded among females, while 6.3% of HBV and 1.9% of co-infection was observed among males and the mean malaria parasitaemia of 2,382.80 µl of blood was observed among females. High prevalence of Hepatitis infection rate of 17.1%, 8.6% of HCV, (6.3%) of HBV and 2.3% of co-infection were recorded among single donors. The mean malaria parasitaemia of 786.89 (µl of blood) was observed among married donors, there was significant difference between marital status and hepatitis infection (p= 0.0043) and between HCV (p=0.009). High prevalence of hepatitis viraemia of 21.4% and co-infection 5.6% was recorded among artisans, while 14.6% HBV infection rate was recorded among civil servants and 14.3% of HCV was recorded among donors who are farmers. The mean malaria parasitaemia of 1,150.15 µl/blood was recorded among donors who are traders. Donors that have acquired primary education have high prevalence of hepatitis infection rate of 38.5%, with 15.4% of HBV and (23.1%) co-infection (HBVand HCV). HCV (6.7%) was high among donors with secondary education; high mean malaria parasitaemia of 2,096.84 µl of blood was recorded among donors with primary education. Blood B+ve had high hepatitis viral infection rate of 21.7%, HCV 13.0% and co-infection of 5.8% while 7.8% of HBV was recorded among O+ve donors. The mean malaria parasitaemia of 1,378.50 (µl of blood) was recorded among B-ve donors. The total mean PCV in the study was 42.63, White blood cell count was 5,281.25, lymphocytes count was 42.88, eosinophils was 1.53 and neutrophil count was 55.72. The total percentage of elevated AST was 5.0%, ALT was 6.0% and ALB was 10.5%. There was significant difference between malaria and ALT (p=0.000) also, there was significant difference between HCV and ALB (p=0.000). There was significant difference between HBV and AST (p=0.001), ALT (p=0.028) and ALB (p=0.028).The hepatitis viral infection had significant difference with ALB (p=0.000). The logistic regression shows that there was an association between hepatitis viral infection and aged group 27-35years (p=0.022), female (p=0.006), trading (p=0.001), tertiary (p=0.003) A+ve (p=0.018) and B+ve (p=0.001). In conclusion, Although, the prevalence of malaria was low, while that of hepatitis viral infection was high in the local government area, critical screening of blood donors is of prime importance because they serve as an asymptomatic reservoirs and a potential source of transmission of these infections. The strengthening of creating awareness on the general public regarding Malaria, HBV and HCV transmission and prevention should be embarked on.

Hepatitis E associated determinants and diagnostic biomarkers during pregnancy and its prenatal consequences in Multan, Punjab tertiary care setting (Pakistan).

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis in the world. Hepatitis E infection is commonly widespread by the fecal oral routes and contaminated water. This study was designed to explore the prevalence and risk factors of hepatitis E infection in pregnant women of the Multan district, Pakistan. The study comprised of a total of 500 enrolled patients, among which, 105 pregnant females with hepatitis E infection fulfilled the criteria for anti-HEV antibodies. Pregnant women without significant complications and without hepatitis E infection were excluded from this study. Hepatic profile, complete blood count, coagulation markers, and standard protocol were also assessed for fetal maternal hemorrhage. Our results showed that 105 patients (66.66%, CI 95%) had HEV infection with mean age 25±5 years. Serum bilirubin levels were increased in 74 patients (70.47%), aspartate transaminase was elevated > 200 IU/L in 71 patients (67.61%), alanine transaminase was above the 100 IU/L in 65 patients (245 IU/L), and low platelet counts were found in 45 patients (42.85%). Moreover, fetal distress cases were 9 (10.84%) and maternal distress cases were about 11 (13.25%). Fetal mortality cases were 39 (37.14%), and maternal mortality cases were about 22 (20.95%) due to hepatic comma, intravascular coagulation, and hepatic failure. It was concluded that the prevalence of Hepatitis E during pregnancy is associated with high risk factors of unhygienic practices, blood transfusion, and noncompliance with universal infection control techniques. Maternal fatalities and fetal consequences were exacerbated by HEV infection.

Annual risk of hepatitis E virus infection and seroreversion: Insights from a serological cohort in Sitakunda, Bangladesh.

Hepatitis E virus (HEV) is a major cause of acute jaundice in South Asia. Gaps in our understanding of transmission are driven by non-specific symptoms and scarcity of diagnostics, impeding rational control strategies. In this context, serological data can provide important proxy measures of infection. We enrolled a population-representative serological cohort of 2,337 individuals in Sitakunda, Bangladesh. We estimated the annual risks of HEV infection and seroreversion both using serostatus changes between paired serum samples collected 9months apart, and by fitting catalytic models to the age-stratified cross-sectional seroprevalence. At baseline, 15% (95 CI: 14-17%) of people were seropositive, with seroprevalence highest in the relatively urban south. During the study, 27 individuals seroreverted (annual seroreversion risk: 15%, 95 CI: 10-21%), and 38 seroconverted (annual infection risk: 3%, 95CI: 2-5%). Relying on cross-sectional seroprevalence data alone, and ignoring seroreversion, underestimated the annual infection risk five-fold (0.6%, 95 CrI: 0.5-0.6%). When we accounted for the observed seroreversion in a reversible catalytic model, infection risk was more consistent with measured seroincidence. Our results quantify HEV infection risk in Sitakunda and highlight the importance of accounting for seroreversion when estimating infection incidence from cross-sectional seroprevalence data.

Hepatitis E Virus (HEV) an increasing threat for consumer’s health in Europe

Hepatitis E virus (HEV) is a main cause of enterically transmitted viral hepatitis in humans. Nowadays HEV infections are reported not only in the developing world, but also in developed countries, in which the number of a new cases increases every year. In Europe genotypes HEV3 and HEV4 are mainly responsible for human hepatitis. These genotypes are considered zoonotic agents associated mainly with pigs and wild boars. The consumption of raw or undercooked pig’s or wild boar’s meat products, especially containing blood and/or liver is the basic reason of human HEV infections in developed countries. The aim of this review is to present current epidemiological data on zoonotic HEV human infections in Europe with particular emphasis on the role of food in the virus transmission.

Translational Insights into Molecular Mechanisms of Chemical Hepatocarcinogenesis for Improved Human Risk Assessment

Background: Hepatocellular carcinoma (HCC) is a prevalent liver cancer with major risk factors being hepatitis viral infections, alcohol, non-alcoholic fatty liver disease, and aflatoxin exposure. Both genotoxic and non-genotoxic agents can induce HCC through mechanisms involving DNA damage, oxidative stress, chronic inflammation, and disrupted signaling pathways like MAPK/ERK, PI3K/AKT, WNT/β-catenin and PPARα. While rodent assays are utilized to detect potential chemical hepatocarcinogens, species differences in pathways like PPARα and CAR/PXR activation impact human risk assessment. Purpose: This analysis provides an updated, critical examination of species concordance in mechanisms of hepatic carcinogenesis to inform human safety assessment of rodent liver tumor findings. Main Body: Rodent assays including 2-year bioassays, transgenic models, and short-term studies detect liver tumors through lifetime exposure or early biomarkers. However, rodent-specific PPARα and CAR/PXR activation, along with human risk factors like hepatitis, highlight key interspecies differences. Determining mode of action relevance requires evaluating mechanistic validity and pivotal key events leading to tumors across species. Non-genotoxic compounds eliciting rodent liver tumors can activate PPARα, CAR/PXR, and other pathways triggering increased cell replication; but downstream signaling may differ in human liver. Understanding applicability of these mechanisms in humans as well as incorporating human risk factors into experimental models is critical for accurate risk assessment. Conclusion: In summary, elucidating conserved versus divergent molecular mechanisms of hepatic carcinogenesis between rodents and humans is essential for appropriately interpreting rodent findings and safeguarding human health through science-based risk assessment frameworks and regulatory decision-making processes around potential chemical hazards.

Prevalence of viral hepatitis (A, B, C, and E) infection and co-infection among hospitalized children in Cairo, Egypt

Viral hepatitis is considered a public health issue facing the entire world. The World Health Organization encouraged all countries to work together to eliminate this fatal infection and achieve the 2030 agenda. The present study aimed to investigate the silent infection of viral hepatitis (A, B, C, and E) among hospitalized children in Cairo, Egypt, to control and avoid chronic infection early on. This cross-sectional study included 184 randomly selected hospitalized children from three different hospitals in Cairo, Egypt. They were children aged between a few months to 15 years to determine viral hepatitis infection and co-infection. Antibodies to hepatitis A virus (HAV IgM), hepatitis E virus (HEV IgM), hepatitis C virus (HCV Ab), and hepatitis B virus surface antigen (HBs Ag) were performed by ELISA. If the ELISA results were positive, the viral load was quantified by real-time polymerase chain reaction (RT-PCR). Other laboratory investigations included alanine aminotransferase, aspartate aminotransferase, albumin, and complete blood count. Only five children (2.71%) had HCV Ab positive with no other viral (A, B, and E) co-infections as determined by ELISA. Also, the RT-PCR detected HCV RNA in these ELISA positive children. The remaining children (179/184) were all negative for all hepatitis viruses’ markers (HAV IgM, HEV IgM, HBs Ag, and HCV Ab). In conclusion, this study documented that, Cairo hospitals serving Egyptian children had a low prevalence of viral hepatitis (A, B, C, and E). More research with larger sample sizes from hospitals across Egypt is needed.

Prevalence and characteristics of hepatic hemangiomas assessed by ultrasound: A single-center experience

Introduction/Objective. Liver hemangioma is the most common benign tumor of the liver, with estimated prevalence of 2.5-4%. This study aimed to investigate the prevalence and clinical characteristics of hepatic hemangioma in one Primary Care Center in Serbia. Methods. We conducted a cross-sectional study, which included patients examined in Primary Care Center "Dr Simo Milosevic" in Belgrade, Serbia (December 2017 - March 2020). Patients with suspected atypical changes, malignancies, viral hepatitis infections, and liver cirrhosis were excluded from the study. Results. A total of 567 patients were included in this study (men 42.5%). In 27 patients (4.76%) a diagnosed of hemangioma was made (male:female ratio: 1.1:1). The total number of hemangiomas detected was 48. Hemangiomas were most commonly found in the right liver lobe (32/48, 66,7%). In this study, hemangiomas were most commonly localized in the fourth liver segment (11/48, 22.9%). The mean diameter of the hemangioma was 13.8 mm. In the half of patients diagnosed with hemangioma, more than one hemangioma was detected (13/27, 48.1%). Conclusion. Hemangiomas of the liver are commonly multiple. No sex difference in hemangioma prevalence was noted. The right liver lobe is the most common hemangioma localization in this study cohort.

Верифікація алгоритмів тестування на ВІЛ з використанням швидких тестів

Верифікація алгоритмів тестування на ВІЛ з використанням швидких тестів

The molecular epidemiology of hepatitis E virus genotype 3 in Canada.

Autochthonous hepatitis E virus (HEV) infection is increasingly reported in industrialized countries and is mostly associated with zoonotic HEV genotype 3 (HEV-3). In this study, we examined the molecular epidemiology of 63 human clinical HEV-3 isolates in Canada between 2014 and 2022. Fifty-five samples were IgM positive, 45 samples were IgG positive and 44 were IgM and IgG positive. The majority of the isolates belong to the subtypes 3a, 3b, and 3j, with high sequence homology to Canadian swine and pork isolates. There were a few isolates that clustered with subtypes 3c, 3e, 3f, 3h, and 3g, and an isolate from chronic infection with a rabbit strain (3ra). Previous studies have demonstrated that the isolates from pork products and swine from Canada belong to subtypes 3a and 3b, therefore, domestic swine HEV is likely responsible for the majority of clinical HEV cases in Canada and further support the hypothesis that swine serve as the main reservoirs for HEV-3 infections. Understanding the associated risk of zoonotic HEV infection requires the establishment of sustainable surveillance strategies at the interface between humans, animals, and the environment within a One-Health framework.

Serological survey on Hepatitis E virus in Namibian dogs, cats, horses, and donkeys.

The present study investigated the seropositivity rate of Hepatitis E virus (HEV) in domestic and working animals in Namibia, which included dogs, cats, horses, and donkeys. HEV poses a growing threat as a significant cause of human hepatitis globally and has several genotypes of varying zoonotic potential. As epidemiological data on the seroprevalence of HEV in Namibia is scarce, a serosurvey was conducted on archived serum samples of 374 dogs, 238 cats, 98 horses, and 60 donkeys collected between 2018 and 2022 from different regions, to assess the potential of these animals as sources of HEV infection. The findings revealed that 10.43% (n = 39/374) canine and 5.88% (n = 14/238) feline samples tested positive for HEV antibodies, whereas no seropositivity was detected in horses and donkeys. The study further examined the risk factors associated with HEV seropositivity, including animal sex, age, and geographical region, and noted a higher prevalence in dogs living in areas with intensive pig farming. Although there is no direct evidence indicating that these animals served as major reservoirs for HEV transmission to humans, the study underscores the importance of preventive measures to minimize contact exposure with pets considering the potential zoonotic risk, especially for susceptible risk groups. Further research is needed to explore the zoonotic potential of domestic animals and the epidemiological links between animal and human HEV transmissions in Namibia.

Modeling the Transmission Routes of Hepatitis E Virus as a Zoonotic Disease Using Fractional‐Order Derivative

Hepatitis E virus (HEV) is one of the emerging zoonotic diseases in Sub‐Saharan Africa. Domestic pigs are considered to be the main reservoir for this infectious disease. A third of the world’s population is thought to have been exposed to the virus. The zoonotic transmission of the HEV raises serious zoonotic and food safety concerns for the general public. This is a major public health issue in both developed and developing countries. The World Health Organization (WHO) estimated that 44,000 people died in 2015 as a result of HEV infection. East and South Asia have the highest prevalence of this disease overall. In this study, we proposed, developed, and analyzed the transmission routes of the infection using a fractional‐order derivative approach. The existence, stability, and uniqueness of solutions were established using the approach and concept in Banach space. Local and global stability was determined using the Hyers–Ulam (HU) stability approach. Numerical simulation was conducted using existing parameter values, and it was established that, as the susceptible human population declines, the number of infected human populations rises with a change in fractional order . When the susceptible pig population increases, the number of infected pig populations rises with a change in . It was observed that a few variations in the fractional derivative order did not alter the function’s overall behavior with the results of numerical simulations. Moreover, as the number of recovered human populations increases, there is a corresponding increase in the population of recovered pigs with a change in . The exponential increase in the infected pig population can be controlled by treatment of the infected pigs and prevention of the susceptible pigs. The authors recommend policymakers, and stakeholders prioritize the fight against the virus by enforcing the prevention of humans and treatment of infected pigs. The model can be extended to optimal control and cost‐effectiveness analysis to determine the most effective control strategy that comes with less cost in the combat of the disease.

Analysis of ZNF208 Polymorphisms on the Clinicopathologic Characteristics of Asian Patients with Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC), a major form of liver cancer, is characterized by high lethality and a multifactorial etiology that includes hepatitis virus infections, lifestyle factors, and genetic predispositions. This study aimed to explore the impact of ZNF208 gene polymorphisms on the clinicopathological features of Taiwanese HCC patients, focusing on three specific single nucleotide polymorphisms (SNPs): rs2188971, rs2188972, and rs8105767. Our cohort consisted of 438 HCC patients and 1193 control individuals. Clinical staging was determined using the tumor/node/metastasis (TNM) system, and various clinical indicators were collected. Our analysis revealed a statistically significant increase in ZNF208 expression in HCC patients compared to controls, indicating a potential role in HCC progression. Although no substantial association was observed between ZNF208 SNPs and increased HCC risk, specific clinical features such as distant metastasis and vascular invasion showed significant associations with these SNPs, suggesting their influence on disease aggressiveness. Demographic analyses highlighted the importance of factors like alcohol consumption and viral hepatitis markers in HCC. Our study underscores the complexity of genetic influences on HCC, with ZNF208 polymorphisms potentially affecting tumor progression and patient outcomes.

Detection of hepatitis viruses in suspected cases of Viral Haemorrhagic Fevers in Nigeria.

There have been several Viral Hemorrhagic Fever (VHF) outbreaks in Nigeria which remains a public health concern. Despite the increasing number of suspected cases of VHF due to heightened surveillance activities and growing awareness, only a few cases are laboratory-confirmed to be VHF. Routinely, these samples are only tested for Lassa virus and Yellow fever virus with occasional testing for Dengue virus when indicated. The aetiology of the disease in these VHF suspected cases in Nigeria which are negative for Lassa, Yellow fever and Dengue viruses remains a puzzle. Since the clinical features exhibited by suspected VHF cases are like other endemic illnesses such as Hepatitis, there is a need to investigate the diversity and co-infections of hepatitis viruses as differentials and possible co-morbidity in suspected cases of VHFs in Nigeria. A total of three hundred and fifty (350) blood samples of 212 (60.6%) males and 138 (39.4%) females, aged <1-70 years with a mean age of 25 ±14.5, suspected of VHFs and tested negative for Lassa, Yellow fever and Dengue viruses were investigated for Hepatitis A, B, C and E viruses at the Centre for Human and Zoonotic Virology (CHAZVY), College of Medicine, University of Lagos (CMUL) using serologic and molecular techniques. The serologic analysis of these VHF suspected cases samples revealed that 126 (36%) were positive for at least one hepatitis virus. Individual prevalence for each of the hepatitis virus screened for showed that 37 (10.6%), 18 (5.1%) and 71 (20.3%) were positive for HBV, HCV and HEV respectively. All the samples were negative for HAV. A co-infection rate of 11.9% was also observed, with HCV/HEV co-infections being the most prevalent and the Northern region having the greatest burden of infection. The evidence of hepatitis virus infections in suspected cases of VHF was documented. Thus, their associations as co-morbidities and/or mortalities in this category of individuals require further investigations in endemic countries such as Nigeria. Therefore, the possible inclusion of screening for hepatitis viruses and other aetiologic agents that could mimic infections in suspected cases of VHFs in Nigeria should be thoroughly evaluated to guide informed policy on the diagnosis and management of these cases.

Evaluation of Alanine Aminotransferase (Alt), Aspatate Aminotransferase (Ast) and Albumin (Alb) Among Blood Donors Infected with Hepatitis B and C Virus and Malaria in Ife Central Local Government Area, Ile Ife, Osun State, Nigeria

Liver diseases are responsible for over one and half million deaths annually and are characterized by permanent inflammatory processes that predispose to liver cancer.Liver function biomarkers are important indices that help in assessment of disease severity. Several studies reveal changes in activity level of liver enzymes and protein in the serum due to Plasmodium infection and Hepatitis infection. Liver enzymes play an important role in the assessment of liver function because of liver injury resulting in cytolysis or necrosis that causes release of enzymes into circulation. Infection with hepatitis B virus (HBV) and hepatitis C virus (HCV) are major global health problems. Moreover, infection with these viruses might associate with increased mortality rate as the infection may predisposes to the development of serious liver diseases such as liver cirrhosis, liver failure and hepatocellular carcinoma (HCC). The objectives of the study are to determine the prevalence Hepatitis B and C infections among blood donors, analyze the relationship between socio- demographic variables and Alanine aminotransferase (ALT), Aspatate aminotransferase (AST) and Albumin (ALB), analyze the relationship between malarial and ALT and AST and evaluate the effect of hepatitis infections on the liver cells. The study was conducted in Ife Central Local Government .Area, Ile Ife, Osun State. Five (5) ml of venous blood was obtained from each of 400 blood donors into plain bottles and labeled accordingly. Sera were separated from aliquots of the blood and screened for hepatitis-B and C surface antigens (HBsAg and HCV), and enzymes such as aspatate aminotransferase (AST) and alanine aminotransferase (ALT). The total percentage of elevated AST was 14(3.5%), ALT 15 (3.8%) and ALB 32(8.0%), while that the least AST 24 (6.0%), ALT 23 (4.8%) and ALB 6 (1.5%). There was significant difference between Occupation and ALT (p= 0.040) and ALB (p= 0.030), Marital status and AST (p=0.014), ALT (p= 0.012), ALB (p=0.014), there was no significant difference between HCV and AST (p=0.532), ALT (p=0.532), but with ALB (p=0.000). There was no significant difference between HBV and AST ( p=0.285), ALT (p=0.593) and ALB (p=0.033), the general hepatitis viral infection had no significant difference with AST ( p=0.516), ALT (p=0.516), but with ALB (p= 0.000), There was no significant difference between malaria infection and AST (p= 0.906), ALT (p= 0.999) and ALB (p= 0.718). in conclusion, although the prevalence hepatitis B and C viral infections was low and there was no significant relationship between the Alanine aminotransferase (ALT), Aspatate aminotransferase,(AST) and Hepatitis infection in the local government, critical screening of blood donors is of prime importance because they serve as an asymptomatic reservoirs and a potential source of transmission of these infections. The strengthening of creating awareness on the general public regarding HBsAg and HCV transmission and prevention should be of paramount important.

Development and evaluation of a CRISPR-Cas13a system-based diagnostic for hepatitis E virus.

Hepatitis E virus (HEV) is the leading cause of acute viral hepatitis worldwide. HEV RNA detection is the goldstandard for HEV infection diagnosis and PCR methods are commonly used but are usually time-consuming and expensive, resulting in low detection efficiency and coverage, especially in low-income areas. Here, we developed a simpler and more accessible HEV RNA detection method based on CRISPR-Cas13a system. A total of 265 samples of different types and sources, including 89 positive samples and 176 negative samples, were enrolled for evaluations. The sensitivity andspecificity of the Cas13a-crRNA detection system were evaluated. The World Health Organization reference panel for HEV genotypes was used to evaluate the capability for detecting different HEV genotypes. The validity of the assay was compared with RT-qPCR. The 95 % limits of detection (LOD) of Cas13a-crRNA-based fluorescence assay and strip assay were 12.5 and 200 IU/mL, respectively. They did not show cross-reactivity with samples positive for hepatitis A virus, hepatitis B virus, hepatitis C virus, coxsackievirus A16, rotavirus, enterovirus 71, norovirus or enteropathic Escherichia coli. Different HEV genotypes (HEV1-4) can be detected by the assay. Compared to RT-qPCR, the positive predictive agreements of Cas13a-crRNA-based fluorescence and strip assay were 98.9 % (95 % CI: 93.9-99.8 %) and 91.0 % (95 % CI: 83.3-95.4 %), respectively. The negative predictive agreements were both 100 % (95 % CI: 97.8-100 %). In conclusion, we established a rapid and convenient HEV RNA detection method with good sensitivity and specificity based on CRISPR-Cas13a system, providing anew option for HEV infection diagnosis.

Efficient formation and maintenance of humoral and CD4 T-cell immunity targeting the viral capsid in acute-resolving hepatitis E infection

CD4 T cells shape the neutralizing antibody (nAb) response and facilitate viral clearance in various infections. Knowledge of their phenotype, specificity and dynamics in hepatitis E virus (HEV) infection is limited. HEV is enterically transmitted as a naked virus (nHEV) but acquires a host-derived quasi-envelope (eHEV) when budding from cells. While nHEV is composed of the open reading frame (ORF)-2-derived capsid, eHEV particles also contain ORF3-derived proteins. We aimed to longitudinally characterize the HEV-specific CD4 T cells targeting ORF1, 2 and 3 and antibodies against nHEV or eHEV in immunocompetent individuals with acute and resolved HEV infection. HEV-specific CD4 T cells were analyzed by intracellular cytokine staining after stimulation with in silico-predicted ORF1- and ORF2-derived epitopes and overlapping peptides spanning the ORF3 region. Exvivo multiparametric characterization of capsid-specific CD4 T cells was performed using customized MHC class II tetramers. Total and neutralizing antibodies targeting nHEV or eHEV particles were determined. HEV-specific CD4 T-cell frequencies and antibody titers are highest in individuals with acute infection and decline in a time-dependent process with an antigen hierarchy. HEV-specific CD4 T cells strongly target the ORF2-derived capsid and ORF3-specific CD4 T cells are hardly detectable. NAbs targeting nHEV are found in high titers while eHEV particles are less efficiently neutralized. Capsid-specific CD4 T cells undergo memory formation and stepwise contraction, accompanied by dynamic phenotypical and transcriptional changes over time. The viral capsid is the main target of HEV-specific CD4 T cells and antibodies in acute-resolving infection, correlating with efficient neutralization of nHEV. Capsid-specific immunity rapidly emerges followed by a stepwise contraction several years after infection. The interplay of CD4 T cells and neutralizing antibody responses is critical in the host defense against viral infections, yet little is known about their characteristics in hepatitis E virus (HEV) infection. We conducted a longitudinal study of immunocompetent individuals with acute and resolved HEV infection to understand the characteristics of HEV-specific CD4 T cells and neutralizing antibodies targeting different viral proteins and particles. We found that HEV-specific CD4 T cells mainly target capsid-derived epitopes. This correlates with efficient neutralization of naked virions while quasi-enveloped particles are less susceptible to neutralization. As individuals with pre-existing liver disease and immunocompromised individuals are at risk for fulminant or chronic courses of HEV infection, these individuals might benefit from the development of vaccination strategies which require a detailed knowledge of the composition and longevity of HEV-specific CD4 T-cell and antibody immunity.

CRISPR/Cas9 as a New Antiviral Strategy for Treating Hepatitis Viral Infections.

Hepatitis is an inflammatory liver disease primarily caused by hepatitis A (HAV), B (HBV), C (HCV), D (HDV), and E (HEV) viruses. The chronic forms of hepatitis resulting from HBV and HCV infections can progress to cirrhosis or hepatocellular carcinoma (HCC), while acute hepatitis can lead to acute liver failure, sometimes resulting in fatality. Viral hepatitis was responsible for over 1 million reported deaths annually. The treatment of hepatitis caused by viral infections currently involves the use of interferon-α (IFN-α), nucleoside inhibitors, and reverse transcriptase inhibitors (for HBV). However, these methods do not always lead to a complete cure for viral infections, and chronic forms of the disease pose significant treatment challenges. These facts underscore the urgent need to explore novel drug developments for the treatment of viral hepatitis. The discovery of the CRISPR/Cas9 system and the subsequent development of various modifications of this system have represented a groundbreaking advance in the quest for innovative strategies in the treatment of viral infections. This technology enables the targeted disruption of specific regions of the genome of infectious agents or the direct manipulation of cellular factors involved in viral replication by introducing a double-strand DNA break, which is targeted by guide RNA (spacer). This review provides a comprehensive summary of our current knowledge regarding the application of the CRISPR/Cas system in the regulation of viral infections caused by HAV, HBV, and HCV. It also highlights new strategies for drug development aimed at addressing both acute and chronic forms of viral hepatitis.

A genome-wide CRISPR/Cas9 screen identifies a role for Rab5A and early endosomes in hepatitis E virus replication.

Hepatitis E virus (HEV) is a major cause of acute hepatitis worldwide. As the other positive-strand RNA viruses, it is believed to replicate its genome in a membrane-associated replication complex. However, current understanding of the host factors required for productive HEV infection is limited and the site as well as the composition of the HEV replication complex are still poorly characterized. To identify host factors required for HEV RNA replication, we performed a genome-wide CRISPR/Cas9 screen in permissive human cell lines harboring subgenomic HEV replicons allowing for positive and negative selection. Among the validated candidates, Ras-related early endosomal protein Rab5A was selected for further characterization. siRNA-mediated silencing of Rab5A and its effectors APPL1 and EEA1, but not of the late and recycling endosome components Rab7A and Rab11A, respectively, significantly reduced HEV RNA replication. Furthermore, pharmacological inhibition of Rab5A and of dynamin-2, required for the formation of early endosomes, resulted in a dose-dependent decrease of HEV RNA replication. Colocalization studies revealed close proximity of Rab5A, the HEV ORF1 protein, corresponding to the viral replicase, as well as HEV positive- and negative-strand RNA. In conclusion, we successfully exploited CRISPR/Cas9 and selectable subgenomic replicons to identify host factors of a noncytolytic virus. This approach revealed a role for Rab5A and early endosomes in HEV RNA replication, likely by serving as a scaffold for the establishment of functional replication complexes. Our findings yield insights into the HEV life cycle and the virus-host interactions required for productive infection.

Identification of cytochrome P450 2C18 and 2C76 in tree shrews: P450 2C18 effectively oxidizes typical human P450 2C9/2C19 chiral substrates warfarin and omeprazole with less stereoselectivity

Cytochromes P450 (P450s or CYPs), especially the CYP2C family, are important drug-metabolizing enzymes that play major roles in drug metabolism. Tree shrews, a non-rodent primate-like species, are used in various fields of biomedical research, notably hepatitis virus infection; however, its drug-metabolizing enzymes have not been fully investigated. In this study, tree shrew CYP2C18, CYP2C76a, CYP2C76b, and CYP2C76c cDNAs were identified and contained open reading frames of 489 or 490 amino acids with high sequence identities (70–78 %) to human CYP2Cs. Tree shrew CYP2C76a, CYP2C76b, and CYP2C76c showed higher sequence identities (79–80 %) to cynomolgus CYP2C76 and were not orthologous to any human CYP2C. Phylogenetic analysis revealed that tree shrew CYP2C18 and CYP2C76s were closely related to rat CYP2Cs and cynomolgus CYP2C76, respectively. Tree shrew CYP2C genes formed a gene cluster similar to human CYP2C genes. All four tree shrew CYP2C mRNAs showed predominant expressions in liver, among the tissue types examined; expression of CYP2C18 mRNA was also detected in small intestine. In liver, CYP2C18 mRNA was the most abundant among the tree shrew CYP2C mRNAs. In metabolic assays using human CYP2C substrates, all tree shrew CYP2Cs showed metabolic activities toward diclofenac, R,S-omeprazole, paclitaxel, and R,S-warfarin, with the activity of CYP2C18 exceeding that of the other CYP2Cs. Moreover, tree shrew CYP2C76 enzymes metabolized progesterone more efficiently than human, cynomolgus, or marmoset CYP2Cs. Therefore, these novel tree shrew CYP2Cs are expressed abundantly in liver, encode functional enzymes that metabolize human CYP2C substrates, and are likely responsible for drug clearances.

Viral Biology and Immune Privilege in the Development of Extrahepatic Manifestations During Hepatitis E Virus Infection.

Hepatitis E virus (HEV) exhibits tropism toward hepatocytes and thus affects the liver; however, HEV may also affect other tissues, including the heart, kidneys, intestines, testicles, and central nervous system. To date, the pathophysiological links between HEV infection and extrahepatic manifestations have not yet been established. Considering that HEV infects multiple types of cells, the direct effects of virus replication in peripheral tissues represent a plausible explanation for extrahepatic manifestations. In addition, since the immune response is crucial in the development of the disease, the immune characteristics of affected tissues should be revisited to identify commonalities explaining the effects of the virus. This review summarizes the most recent advances in understanding the virus biology and immune-privileged status of specific tissues as major elements for HEV replication in diverse organs. These discoveries may open avenues to explain the multiple extrahepatic manifestations associated with HEV infection and ultimately to design effective strategies for infection control.