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BMC Veterinary Research Jun 2024Equid alphaherpesvirus 1 (EHV-1) is a ubiquitous and significant viral pathogen in horses worldwide, causing a range of conditions, including fever, respiratory disease,...
Equid alphaherpesvirus 1 (EHV-1) is a ubiquitous and significant viral pathogen in horses worldwide, causing a range of conditions, including fever, respiratory disease, abortion in pregnant mares and the severe neurological disease called equine herpes myeloencephalopathy (EHM). Despite that EHV-1 is a notifiable animal disease in Sweden, there is limited knowledge about the circulating strains. This study aimed to analyze the genetic diversity of EHV-1 strains in equine samples from different Swedish outbreaks by partial genome sequencing. Genotyping based on three selected open reading frames ORF11, ORF30, and ORF34 in the viral genome was conducted for 55 outbreaks of EHV-1 spanning from the years 2012 to 2021. The analysis revealed 14 different genovariants, with one prominent genovariant identified in 49% of the outbreaks. Additionally, the study identified seven mutations not previously described. Three new mutations were demonstrated in ORF11, all synonymous, and four new mutations in ORF34, two synonymous, and two non-synonymous. Notably, different EHV-1 genovariants were found in five out of six studied EHM outbreaks, but clonal spreading was shown within the outbreaks. Moreover, the study demonstrated that healthy (recovered) horses that returned from an EHM outbreak at an international meeting in Valencia, Spain (2021), were positive for the virus clone responsible for the severe disease outbreak despite several weeks of quarantine. These findings shed light on the genetic diversity and transmission dynamics of the virus and significantly contribute to better understanding of the epidemiology of EHV-1 in Sweden and globally.
Topics: Animals; Horses; Sweden; Herpesvirus 1, Equid; Horse Diseases; Disease Outbreaks; Herpesviridae Infections; Genetic Variation; Genome, Viral; Genotype; Open Reading Frames
PubMed: 38909196
DOI: 10.1186/s12917-024-04096-7 -
Nature Communications Jun 2024During primary varicella zoster virus (VZV) infection, infected lymphocytes drive primary viremia, causing systemic dissemination throughout the host, including the...
During primary varicella zoster virus (VZV) infection, infected lymphocytes drive primary viremia, causing systemic dissemination throughout the host, including the skin. This results in cytokine expression, including interferons (IFNs), which partly limit infection. VZV also spreads from skin keratinocytes to lymphocytes prior to secondary viremia. It is not clear how VZV achieves this while evading the cytokine response. Here, we show that VZV glycoprotein C (gC) binds IFN-γ and modifies its activity, increasing the expression of a subset of IFN-stimulated genes (ISGs), including intercellular adhesion molecule 1 (ICAM1), chemokines and immunomodulatory genes. The higher ICAM1 protein level at the plasma membrane of keratinocytes facilitates lymphocyte function-associated antigen 1-dependent T cell adhesion and expression of gC during infection increases VZV spread to peripheral blood mononuclear cells. This constitutes the discovery of a strategy to modulate IFN-γ activity, upregulating a subset of ISGs, promoting enhanced lymphocyte adhesion and virus spread.
Topics: Humans; Interferon-gamma; Cell Adhesion; T-Lymphocytes; Intercellular Adhesion Molecule-1; Keratinocytes; Herpesvirus 3, Human; Varicella Zoster Virus Infection; Leukocytes, Mononuclear; Viral Envelope Proteins; Lymphocyte Function-Associated Antigen-1
PubMed: 38909022
DOI: 10.1038/s41467-024-49657-4 -
Applied Microbiology and Biotechnology Jun 2024Herpes simplex virus type 1 (HSV-1) plays an important role in the field of gene therapy and viral vaccines, especially as an oncolytic virus. However, the mass...
Herpes simplex virus type 1 (HSV-1) plays an important role in the field of gene therapy and viral vaccines, especially as an oncolytic virus. However, the mass production of HSV-1 viral vectors remains a challenge in the industry. In this study, a microcarrier-mediated serum-reduced medium culture was used to improve the bioprocess of HSV-1 production and increase HSV-1 yields. The composition of the culture media, which included a basal medium, serum concentration, and glutamine additive, was optimized. The process was successfully conducted in a 1 L bioreactor, and virus production was threefold greater than that of conventional processes with a 10% serum medium. The bead-to-bead transfer process was also developed to further increase scalability. In spinner flasks, the detachment rate increased from 49.4 to 80.6% when combined agitation was performed during digestion; the overall recovery proportion increased from 37.9 to 71.1% after the operational steps were optimized. Specifically, microcarrier loss was reduced during aspiration and transfer, and microcarriers and detached cells were separated with filters. Comparable cell growth was achieved with the baseline process using 2D culture as the inoculum by exchanging the subculture medium. To increase virus production after bead-to-bead transfer, critical parameters, including shear stress during digestion, TrypLE and EDTA concentrations in the subculture, and the CCI, were identified from 47 parameters via correlation analysis and principal component analysis. The optimized bead-to-bead transfer process achieved an average of 90.4% overall recovery and comparable virus production compared to that of the baseline process. This study is the first to report the optimization of HSV-1 production in Vero cells cultured on microcarriers in serum-reduced medium after bead-to-bead transfer. KEY POINTS: • An HSV-1 production process was developed that involves culturing in serum-reduced medium, and this process achieved threefold greater virus production than that of traditional processes. • An indirect bead-to-bead transfer process was developed with over 90% recovery yield in bioreactors. • HSV-1 production after bead-to-bead transfer was optimized and was comparable to that achieved with 2D culture as inoculum.
Topics: Herpesvirus 1, Human; Bioreactors; Culture Media; Chlorocebus aethiops; Virus Cultivation; Vero Cells; Animals
PubMed: 38896301
DOI: 10.1007/s00253-024-13193-4 -
Frontiers in Immunology 2024Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive sarcomas with unacceptably low cure rates occurring often in patients with neurofibromatosis 1 defects....
INTRODUCTION
Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive sarcomas with unacceptably low cure rates occurring often in patients with neurofibromatosis 1 defects. To investigate oncolytic Herpes Simplex Virus (oHSV) as an immunotherapeutic approach, we compared viral replication, functional activity, and immune response between unarmed and interleukin 12 (IL-12)-armed oncolytic viruses in virus-permissive (B109) and -resistant (67C-4) murine MPNSTs.
METHODS
This study compared two attenuated IL-12-oHSVs with γ134.5 gene deletions (Δγ134.5) and the same transgene expression cassette. The primary difference in the IL-12-oHSVs was in their ability to counter the translational arrest response in infected cells. Unlike M002 (Δγ134.5, mIL-12), C002 (Δγ134.5, mIL-12, IRS1) expresses an HCMV IRS1 gene and evades dsRNA activated translational arrest in infected cells.
RESULTS AND DISCUSSION
Our results show that oHSV replication and gene expression results in vitro were not predictive of oHSV direct oncolytic activity in vivo. Tumors that supported viral replication in cell culture studies resisted viral replication by both oHSVs and restricted M002 transgene expression in vivo. Furthermore, two IL-12-oHSVs with equivalent transcriptional activity differed in IL-12 protein production in vivo, and the differences in IL-12 protein levels were reflected in immune infiltrate activity changes as well as tumor growth suppression differences between the IL-12-oHSVs. C002-treated tumors exhibited sustained IL-12 production with improved dendritic cells, monocyte-macrophage activity (MHCII, CD80/CD86 upregulation) and a polyfunctional Th1-cell response in the tumor infiltrates.
CONCLUSION
These results suggest that transgene protein production differences between oHSVs in vivo, in addition to replication differences, can impact OV-therapeutic activity.
Topics: Animals; Interleukin-12; Mice; Oncolytic Virotherapy; Oncolytic Viruses; Transgenes; Virus Replication; Cell Line, Tumor; Immunotherapy; Humans; Simplexvirus; Dendritic Cells; Female
PubMed: 38895115
DOI: 10.3389/fimmu.2024.1375413 -
Frontiers in Immunology 2024Varicella zoster virus (VZV) causes varicella and can reactivate as herpes zoster, and both diseases present a significant burden worldwide. However, the mechanisms by...
INTRODUCTION
Varicella zoster virus (VZV) causes varicella and can reactivate as herpes zoster, and both diseases present a significant burden worldwide. However, the mechanisms by which VZV establishes latency in the sensory ganglia and disseminates to these sites remain unclear.
METHODS
We combined a single-cell sequencing approach and a well-established rhesus macaque experimental model using Simian varicella virus (SVV), which recapitulates the VZV infection in humans, to define the acute immune response to SVV in the lung as well as compare the transcriptome of infected and bystander lung-resident T cells and macrophages.
RESULTS AND DISCUSSION
Our analysis showed a decrease in the frequency of alveolar macrophages concomitant with an increase in that of infiltrating macrophages expressing antiviral genes as well as proliferating T cells, effector CD8 T cells, and T cells expressing granzyme A (GZMA) shortly after infection. Moreover, infected T cells harbored higher numbers of viral transcripts compared to infected macrophages. Furthermore, genes associated with cellular metabolism (glycolysis and oxidative phosphorylation) showed differential expression in infected cells, suggesting adaptations to support viral replication. Overall, these data suggest that SVV infection remodels the transcriptome of bystander and infected lung-resident T cells and macrophages.
Topics: Animals; Macaca mulatta; Lung; Macrophages, Alveolar; Transcriptome; T-Lymphocytes; Varicellovirus; Macrophages; Herpesviridae Infections; Herpesvirus 3, Human; Disease Models, Animal; Single-Cell Analysis
PubMed: 38887303
DOI: 10.3389/fimmu.2024.1408212 -
Nature Communications Jun 2024This study investigates the role of circular RNAs (circRNAs) in the context of Varicella-Zoster Virus (VZV) lytic infection. We employ two sequencing technologies,...
This study investigates the role of circular RNAs (circRNAs) in the context of Varicella-Zoster Virus (VZV) lytic infection. We employ two sequencing technologies, short-read sequencing and long-read sequencing, following RNase R treatment on VZV-infected neuroblastoma cells to identify and characterize both cellular and viral circRNAs. Our large scanning analysis identifies and subsequent experiments confirm 200 VZV circRNAs. Moreover, we discover numerous VZV latency-associated transcripts (VLTs)-like circRNAs (circVLTs), which contain multiple exons and different isoforms within the same back-splicing breakpoint. To understand the functional significance of these circVLTs, we utilize the Bacteria Artificial Chromosome system to disrupt the expression of viral circRNAs in genomic DNA location. We reveal that the sequence flanking circVLTs' 5' splice donor plays a pivotal role as a cis-acting element in the formation of circVLTs. The circVLTs is dispensable for VZV replication, but the mutation downstream of circVLTs exon 5 leads to increased acyclovir sensitivity in VZV infection models. This suggests that circVLTs may have a role in modulating the sensitivity to antiviral treatment. The findings shed new insight into the regulation of cellular and viral transcription during VZV lytic infection, emphasizing the intricate interplay between circRNAs and viral processes.
Topics: RNA, Circular; Herpesvirus 3, Human; Humans; RNA, Viral; Virus Replication; Cell Line, Tumor; Virus Latency; Varicella Zoster Virus Infection; Acyclovir; Exons
PubMed: 38858365
DOI: 10.1038/s41467-024-49112-4 -
PLoS Pathogens Jun 2024Multiple functions are associated with HSV-1 latency associated transcript (LAT), including establishment of latency, virus reactivation, and antiapoptotic activity. LAT...
The anti-apoptotic function of HSV-1 LAT in neuronal cell cultures but not its function during reactivation correlates with expression of two small non-coding RNAs, sncRNA1&2.
Multiple functions are associated with HSV-1 latency associated transcript (LAT), including establishment of latency, virus reactivation, and antiapoptotic activity. LAT encodes two sncRNAs that are not miRNAs and previously it was shown that they have antiapoptotic activity in vitro. To determine if we can separate the antiapoptotic function of LAT from its latency-reactivation function, we deleted sncRNA1 and sncRNA2 sequences in HSV-1 strain McKrae, creating ΔsncRNA1&2 recombinant virus. Deletion of the sncRNA1&2 in ΔsncRNA1&2 virus was confirmed by complete sequencing of ΔsncRNA1&2 virus and its parental virus. Replication of ΔsncRNA1&2 virus in tissue culture or in the eyes of WT infected mice was similar to that of HSV-1 strain McKrae (LAT-plus) and dLAT2903 (LAT-minus) viruses. The levels of gB DNA in trigeminal ganglia (TG) of mice latently infected with ΔsncRNA1&2 virus was intermediate to that of dLAT2903 and McKrae infected mice, while levels of LAT in TG of latently infected ΔsncRNA1&2 mice was significantly higher than in McKrae infected mice. Similarly, the levels of LAT expression in Neuro-2A cells infected with ΔsncRNA1&2 virus was significantly higher than in McKrae infected cells. Reactivation in TG of ΔsncRNA1&2 infected mice was similar to that of McKrae and time of reactivation in both groups were significantly faster than dLAT2903 infected mice. However, levels of apoptosis in Neuro-2A cells infected with ΔsncRNA1&2 virus was similar to that of dLAT2903 and significantly higher than that of McKrae infected cells. Our results suggest that the antiapoptotic function of LAT resides within the two sncRNAs, which works independently of its latency-reactivation function and it has suppressive effect on LAT expression in vivo and in vitro.
Topics: Animals; Mice; Herpesvirus 1, Human; Apoptosis; Virus Activation; Neurons; Virus Latency; RNA, Viral; RNA, Small Untranslated; Cells, Cultured; Female; MicroRNAs
PubMed: 38857310
DOI: 10.1371/journal.ppat.1012307 -
PLoS Pathogens Jun 2024HSV infects keratinocytes in the epidermis of skin via nectin-1. We established a human foreskin explant infection model to investigate HSV entry and spread. HSV1 entry...
HSV infects keratinocytes in the epidermis of skin via nectin-1. We established a human foreskin explant infection model to investigate HSV entry and spread. HSV1 entry could only be achieved by the topical application of virus via high density microarray projections (HD-MAPs) to the epidermis, which penetrated beyond one third of its thickness, simulating in vivo microtrauma. Rapid lateral spread of HSV1 to a mean of 13 keratinocytes wide occurred after 24 hours and free virus particles were observed between keratinocytes, consistent with an intercellular route of spread. Nectin-1 staining was markedly decreased in foci of infection in the epidermis and in the human keratinocyte HaCaT cell line. Nectin-1 was redistributed, at the protein level, in adjacent uninfected cells surrounding infection, inducible by CCL3, IL-8 (or CXCL8), and possibly CXCL10 and IL-6, thus facilitating spread. These findings provide the first insights into HSV1 entry and spread in human inner foreskin in situ.
Topics: Humans; Male; Keratinocytes; Foreskin; Nectins; Herpes Simplex; Chemokines; Herpesvirus 1, Human; Cell Adhesion Molecules; Virus Internalization
PubMed: 38857290
DOI: 10.1371/journal.ppat.1012267 -
BMC Infectious Diseases Jun 2024Herpes simplex encephalitis (HSE) is an important central nervous infection with severe neurological sequelae. The aim of this study was to describe clinical...
BACKGROUND
Herpes simplex encephalitis (HSE) is an important central nervous infection with severe neurological sequelae. The aim of this study was to describe clinical characteristic and outcomes of patients with HSE in Vietnam.
METHODS
This was a retrospective study of 66 patients with herpes simplex encephalitis who admitted to the National Hospital for Tropical Diseases, Hanoi, Vietnam from 2018 to 2021. The detection of herpes simplex virus (HSV) in cerebrospinal fluid was made by the real-time PCR assay. We reported the clinical manifestation on admission and evaluated clinical outcomes at the hospital discharge by modified Rankin Scale (mRS). Multivariate logistic regression analysis was used to analyze the independent risk factors of severe outcomes.
RESULTS
Of the 66 patients with laboratory confirmed HSE, the median age was 53 years (IQR 38-60) and 44 patients (69.7%) were male. The most common manifestations included fever (100%), followed by the consciousness disorder (95.5%). Other neurological manifestation were seizures (36.4%), memory disorders (31.8%), language disorders (19.7%) and behavioral disorders (13.6%). Conventional magnetic resonance imaging (MRI) showed 93.8% patients with temporal lobe lesions, followed by abnormalities in insula (50%), frontal lobe (34.4%) and 48.4% of patients had bilateral lesions. At discharge, 19 patients (28.8%) completely recovered, 15 patients (22.7%) had mild sequelae, 28 patients (42.4%) had moderate to severe sequelae. Severe neurological sequelae were memory disorders (55.8%), movement disorders (53.5%), language disorders (30.2%). Multivariate logistic regression analysis showed that Glasgow score decrement at admission, seizures, and time duration from onset of symptoms to the start of Acyclovir treatment > 4 days were independent factors associated with severe outcomes in HSE patients.
CONCLUSION
Glasgow score decrement, seizures and delay treatment with Acyclovir were associated with the poor outcome of patients with HSE.
Topics: Humans; Male; Female; Middle Aged; Retrospective Studies; Vietnam; Adult; Encephalitis, Herpes Simplex; Antiviral Agents; Simplexvirus; Risk Factors; Magnetic Resonance Imaging; Acyclovir; Treatment Outcome
PubMed: 38831304
DOI: 10.1186/s12879-024-09453-3 -
PLoS Pathogens Jun 2024Proper transcription regulation by key transcription factors, such as IRF3, is critical for anti-viral defense. Dynamics of enhancer activity play important roles in...
Proper transcription regulation by key transcription factors, such as IRF3, is critical for anti-viral defense. Dynamics of enhancer activity play important roles in many biological processes, and epigenomic analysis is used to determine the involved enhancers and transcription factors. To determine new transcription factors in anti-DNA-virus response, we have performed H3K27ac ChIP-Seq and identified three transcription factors, NR2F6, MEF2D and MAFF, in promoting HSV-1 replication. NR2F6 promotes HSV-1 replication and gene expression in vitro and in vivo, but not dependent on cGAS/STING pathway. NR2F6 binds to the promoter of MAP3K5 and activates AP-1/c-Jun pathway, which is critical for DNA virus replication. On the other hand, NR2F6 is transcriptionally repressed by c-Jun and forms a negative feedback loop. Meanwhile, cGAS/STING innate immunity signaling represses NR2F6 through STAT3. Taken together, we have identified new transcription factors and revealed the underlying mechanisms involved in the network between DNA viruses and host cells.
Topics: Immunity, Innate; Humans; Animals; Herpesvirus 1, Human; Mice; Virus Replication; Herpes Simplex; Signal Transduction; HEK293 Cells; Repressor Proteins
PubMed: 38829910
DOI: 10.1371/journal.ppat.1012271