Journal of Medical Virology最新文献

Epstein‒Barr virus (EBV) regulates the expression of host genes involved in functional pathways for viral infection and pathogenicity. Long noncoding RNAs (lncRNAs) have been found to be important regulators of cellular biology. However, how EBV affects host biological processes via lncRNAs remains elusive. Eukaryotic initiation factor 4A3 (EIF4A3) was recently identified as an essential controller of cell fate with an unknown role in EBV infection. Here, the expression of lncRNA brain cytoplasmic 200 (BC200) was shown to be significantly upregulated in EBV-infected cell lines. RNA immunoprecipitation and RNA pulldown assays confirmed that BC200 bound to EIF4A3. Moreover, BC200 promoted EIF4A3 expression at the protein level but not at the mRNA level. Mechanistically, BC200 stabilized the EIF4A3 protein by impeding the K48-linked polyubiquitination of the K195 and K198 residues of EIF4A3. In addition, RNA-seq analysis of EBV-positive cells with knockdown of either BC200 or EIF4A3 revealed that a broad range of cellular genes were differentially regulated, particularly those related to virus infection and immune response pathways. This study is the first to reveal the key residues involved in EIF4A3 polyubiquitination and elucidate the novel regulatory role of EBV in host gene expression via the BC200/EIF4A3 axis. These results have implications for the pathogenesis and treatment of EBV-related diseases.

To clarify the epidemiology of enterovirus D68 (EV-D68), an enterovirus rarely identified in the 20th century, we performed seroepidemiological analysis against EV-D68 using sera collected in 1976, 1985, 1990, 1999, 2009, and 2019, as well as Yamagata isolate (EVD68/Yamagata.JPN/2023-89), in Yamagata, Japan. The neutralizing antibody (Ab)-positive rates for those under 20 years old were 61.0%, 82.5%, 84.3%, 46.7%, 50.5%, and 67.9%, in each year, whereas the rates for those above 20 years old were between 93.4% and 99.1%. Generally, geometric mean titers (GMTs）increased with age among children and the total GMT in each year was 25.4, 49.2, 37.2, 30.8, 29.5, and 33.9, from 1976 to 2019, respectively. The findings in this Yamagata-based study showed that the seroprevalence of EV-D68 over the last four decades has increased with age among children, as a susceptible group, and then reaches a plateau of over approximately 80% among adults. This study clearly revealed that EV-D68 was stably transmitted among children in the 20th century, when EV-D68 detection was quite rare.

Ebola disease (EBOD) in humans is a severe disease caused by at least four related viruses in the genus Orthoebolavirus, most often by the eponymous Ebola virus. Due to human-to-human transmission and incomplete success in treating cases despite promising therapeutic development, EBOD is a high priority in public health research. Yet despite almost 50 years since EBOD was first described, the sources of these viruses remain undefined and much remains to be understood about the disease epidemiology and virus emergence and spread. One important approach to improve our understanding is detection of antibodies that can reveal past human infections. However, serosurveys routinely describe seroprevalences that imply infection rates much higher than those clinically observed. Proposed hypotheses to explain this difference include existence of common but less pathogenic strains or relatives of these viruses, misidentification of EBOD as something else, and a higher proportion of subclinical infections than currently appreciated. The work presented here maps B-cell epitopes in the spike protein of Ebola virus and describes a single epitope that is cross-reactive with an antigen seemingly unrelated to orthoebolaviruses. Antibodies against this epitope appear to explain most of the unexpected reactivity towards the spike, arguing against common but unidentified infections in the population. Importantly, antibodies of cross-reactive donors from within and outside the known EBOD geographic range bound the same epitope. In light of this finding, it is plausible that epitope mapping enables broadly applicable specificity improvements in the field of serology.

Borna disease virus 1 (BoDV-1) is a neurotropic RNA virus that has been linked to fatal BoDV-1 encephalitis (BVE) in humans. Ferroptosis represents a newly recognized kind of programmed cell death that marked by iron overload and lipid peroxidation. Various viral infections are closely related to ferroptosis. However, the link between BoDV-1 infection and ferroptosis, as well as its role in BVE pathogenesis, remains inadequately understood. Herein, we used primary rat cortical neurons, human microglial HMC3 cells, and Sprague‒Dawley rats as models. BoDV-1 infection induced ferroptosis, as ferroptosis characteristics were detected (iron overload, reactive oxygen species buildup, decreased antioxidant capacity, lipid peroxidation, and mitochondrial damage). Analysis via qRT-PCR and Western blot demonstrated that BoDV-1-induced ferroptosis was mediated through Nrf2/HO-1/SLC7a11/GPX4 antioxidant pathway suppression. Nrf2 downregulation was due to BoDV-1 infection promoting Nrf2 ubiquitination and degradation. Following BoDV-1-induced ferroptosis, the PTGS2/PGE2 signaling pathway was activated, and various intracellular lipid peroxidation products and damage-associated molecular patterns were released, contributing to BVE occurrence and progression. More importantly, inhibiting ferroptosis or the ubiquitin‒proteasome system effectively alleviated BVE. Collectively, these findings demonstrate the interaction between BoDV-1 infection and ferroptosis and reveal BoDV-1-induced ferroptosis as an underlying pathogenic mechanism of BVE.

Kaposi's Sarcoma Herpesvirus (KSHV) is the causative agent of several human diseases. There are no cures for KSHV infection. KSHV establishes biphasic lifelong infections. During the lytic phase, new genomes are replicated by seven viral DNA replication proteins. The processivity factor's (PF-8) functions to tether DNA polymerase to DNA, so new viral genomes are efficiently synthesized. PF-8 self-associates, interacts with KSHV DNA replication proteins and the viral DNA. Inhibition of viral DNA replication would diminish the infection within a host and reduce transmission to new individuals. In this review we summarize PF-8 molecular and structural studies, detail the essential protein-protein and nucleic acid interactions needed for efficient lytic DNA replication, identify future areas for investigation and propose PF-8 as a promising antiviral target. Additionally, we discuss similarities that the processivity factor from Epstein-Barr virus shares with PF-8, which could promote a pan-herpesvirus antiviral therapeutic targeting strategy.

This study aimed to assess the impact of COVID-19 on the prevalence of adenovirus (AdV) infection in children. This study retrospectively analyzed the changes in the epidemiological and clinical features of AdV-associated respiratory infections in children in Hangzhou, China, between January 2019 and July 2024. A total of 771 316 samples were included in the study, and the positive rate was 6.10% (47 050/771 316). Among them, the positive rate of AdV infection was highest in 2019, reaching 11.29% (26 929/238 333), while the positive rates in the remaining years were between 2% and 9%. In terms of seasonal epidemic characteristics, the summer of 2019 was the peak of AdV incidence, with the positive rate peaking at around 16.95% (7275/45 268), followed by a gradual decline and a low-level epidemic in winter, with a positive rate of 8.79% (8094/92 060). However, during the period 2020−2024, the AdV epidemic season did not show any significant regularity. Gender analysis revealed that the positive rate of male patients was generally greater than that of female patients. In different age groups, the population susceptible to AdV changed before and after the epidemic. In the early and middle stages of the COVID-19 epidemic, the susceptible population was mainly 2−5 years old, whereas in the later stages of the epidemic, the susceptible population was 5−18 years old. In addition, the main clinical symptoms of AdV-positive children from 2019−2024 were respiratory tract symptoms and fever. In summary, the COVID-19 epidemic has had a certain impact on the prevalence of AdV. These findings provide an important basis and reference for the prevention and diagnosis of AdV, especially in the context of increasing age- and gender-specific public health strategies.

The COVID-19 pandemic had a significant impact on the global influenza vaccination and the epidemics of seasonal influenza. To further explore the molecular epidemiology of influenza viruses and assess vaccine effectiveness, we collected influenza cases in Wuhan during the 2022–2023 influenza season. Among 1312 clinical samples, 312 samples tested positive for influenza viruses using reverse transcription polymerase chain reaction. These positive samples included 146A/H1N1 subtypes (46.8%), 164A/H3N2 subtypes (52.6%) and 2 influenza B virus types (0.6%). Based on the whole genome sequence information of hemagglutinin (HA) and neuraminidase (NA) from 27A/H1N1 influenza virus strains and 26A/H3N2 influenza virus strains obtained in this study, a phylogenetic analysis was conducted. The analysis revealed that all A/H1N1 strains belonged to the evolutionary branch 6B.1A.5a.2a, and they exhibited specific substitutions at positions K71Q, Q206E, E241A, and R276K. Similarly, all A/H3N2 strains were classified into the 3C.2a1b.2a.1a subclade and displayed amino acid substitutions at positions S172H, N175Y, I176T, K187N, and S214P. Notably, the A/H3N2 strains also acquired a new potential glycosylation site at position N174. Using an epitope model, the predicted vaccine effectiveness was assessed for the A/H1N1 and A/H3N2 strains. The predicted vaccine effectiveness against the Wuhan influenza epidemic strain was over 85% for the A/H1N1 vaccine strain. However, the effectiveness against the A/H3N2 vaccine strain was only 48.7%. To further verify the protection of influenza vaccine against circulating influenza viruses in the region, we conducted in vivo and in vitro animal studies. The results of in vitro neutralization experiment showed that rabbit serum antibodies inoculated with quadrivalent isolated influenza vaccine had neutralization ability against all 24 isolated influenza viruses. In vivo experiments showed that vaccinated mice had fewer lung lesions when infected with the influenza strain circulating in Wuhan, suggesting that vaccination can effectively reduce the occurrence of severe lung damage. These findings emphasize the importance of accurately predicting seasonal influenza strains for effective influenza prevention and control, especially during the co-circulation of SARS-CoV-2 and influenza viruses. This study provides valuable information on the seasonal influenza virus in Wuhan during the COVID-19 pandemic and serves as a basis for vaccine prediction and updates.

BRAAVE (NCT03631732), a Phase 3b, multicenter, open-label US study, demonstrated the efficacy of switching to bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) among Black individuals with suppressed HIV through 48 weeks. Here, 72-week resistance, adherence, and virologic outcomes are presented. Enrollment criteria permitted nonnucleoside reverse transcriptase inhibitor (NNRTI)–resistance (R), protease inhibitor (PI)–R, and certain nucleos(t)ide reverse transcriptase inhibitor (NRTI)–R (M184V/I allowed; ≥3 thymidine analog mutations [TAMs] excluded); but excluded primary integrase strand transfer inhibitor (INSTI)-R. Pre-existing resistance was determined using historical genotypes and retrospective baseline proviral DNA genotyping. Adherence, virologic outcomes, and viral blips were assessed. Of 489 participants receiving B/F/TAF with ≥1 post-switch HIV-1 RNA measurement: pre-existing NRTI-R (15% of participants), M184V/I (11%), ≥1 TAMs (8%), NNRTI-R (22%), and PI-R (13%) were observed; pre-existing INSTI-R substitutions (2%) were detected post-randomization; mean viral blip frequency was 0.9% across all timepoints (unassociated with virologic failure); 24% of participants had <95% adherence (98% of whom had HIV-1 RNA <50 copies/mL at last visit); none had treatment-emergent study-drug resistance. Overall, 99% of participants, including all with baseline NRTI-R/INSTI-R, had HIV-1 RNA <50 copies/mL at the last visit, demonstrating that B/F/TAF maintained virologic suppression through 72 weeks regardless of pre-existing resistance, viral blips, and suboptimal adherence.

Organ transplant recipients with hepatitis E virus (HEV) infection bears high risk to develop chronic hepatitis, which is generally associated with immunosuppressive therapies. This study aimed to identify the incidence and predictors of de novo HEV infection in patients after receiving transplantation. We performed a large retrospective study to investigate the prevalence of anti-HEV at baseline, incidence of de novo HEV infection after transplantation, and the risk factors of HEV infection among patients with liver transplant in China. A total of 407 liver transplant recipients were examined for the presence of anti-HEV immunoglobulin G, IgM antibodies, and HEV RNA in serum. Basal indexes in individuals with evidence of post-transplant HEV infection were compared with those without evidence of that, and risk factors associated with HEV infection were assessed. The prevalence of anti-HEV at pretransplant in liver transplant recipients was 25.8% (105/407). Serum-negative conversion occurred in 34 (32.38%) of 105 liver transplant patients. Sixty-five out of 302 patients had de novo HEV infection after transplantation, with a cumulative incidence of 42.74% during follow-up. After transplantation, HEV infection was associated with liver failure (p = 0.012), hypoproteinemia (p = 0.030) and higher level of r-glutamyl transferase (GGT) (p = 0.022) before transplantation. Graft rejection (OR = 0.075; p = 0.045) was negatively associated with serum-negative conversion in patients who had positive anti-HEV antibody before transplantation. The incidence of de novo HEV infection after transplantation were higher in China. Liver failure, hypoproteinemia, and GGT elevation may be associated with HEV infection after liver transplantation. This study suggests that prevention and control of HEV infection after liver transplantation should be paid attention in patients bearing these risk factors.