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Journal of Biomedical Science May 2024Infections with Herpes simplex virus (HSV)-1 or -2 usually present as mild chronic recurrent disease, however in rare cases can result in life-threatening conditions...
BACKGROUND
Infections with Herpes simplex virus (HSV)-1 or -2 usually present as mild chronic recurrent disease, however in rare cases can result in life-threatening conditions with a large spectrum of pathology. Monoclonal antibody therapy has great potential especially to treat infections with virus resistant to standard therapies. HDIT101, a humanized IgG targeting HSV-1/2 gB was previously investigated in phase 2 clinical trials. The aim of this study was to develop a next-generation therapy by combining different antiviral monoclonal antibodies.
METHODS
A lymph-node derived phage display library (LYNDAL) was screened against recombinant gB from Herpes simplex virus (HSV) -1 and HDIT102 scFv was selected for its binding characteristics using bio-layer interferometry. HDIT102 was further developed as fully human IgG and tested alone or in combination with HDIT101, a clinically tested humanized anti-HSV IgG, in vitro and in vivo. T-cell stimulating activities by antigen-presenting cells treated with IgG-HSV immune complexes were analyzed using primary human cells. To determine the epitopes, the cryo-EM structures of HDIT101 or HDIT102 Fab bound to HSV-1F as well as HSV-2G gB protein were solved at resolutions < 3.5 Å.
RESULTS
HDIT102 Fab showed strong binding to HSV-1F gB with Kd of 8.95 × 10 M and to HSV-2G gB with Kd of 3.29 × 10 M. Neutralization of cell-free virus and inhibition of cell-to-cell spread were comparable between HDIT101 and HDIT102. Both antibodies induced internalization of gB from the cell surface into acidic endosomes by binding distinct epitopes in domain I of gB and compete for binding. CryoEM analyses revealed the ability to form heterogenic immune complexes consisting of two HDIT102 and one HDIT101 Fab bound to one gB trimeric molecule. Both antibodies mediated antibody-dependent phagocytosis by antigen presenting cells which stimulated autologous T-cell activation. In vivo, the combination of HDIT101 and HDIT102 demonstrated synergistic effects on survival and clinical outcome in immunocompetent BALB/cOlaHsd mice.
CONCLUSION
This biochemical and immunological study showcases the potential of an effective combination therapy with two monoclonal anti-gB IgGs for the treatment of HSV-1/2 induced disease conditions.
Topics: Humans; Animals; Mice; Herpes Simplex; Antibodies, Monoclonal; Antibodies, Viral; Herpesvirus 1, Human; Mice, Inbred BALB C; Female; Herpesvirus 2, Human
PubMed: 38807208
DOI: 10.1186/s12929-024-01045-2 -
Virology Aug 2024Glycoprotein C (gC), one of ∼12 HSV-1 envelope glycoproteins, carries out several important functions during infection, including the enhancement of virion attachment...
Glycoprotein C (gC), one of ∼12 HSV-1 envelope glycoproteins, carries out several important functions during infection, including the enhancement of virion attachment by binding to host cell heparan sulfate proteoglycans (HSPG). Here we report that gC can also enhance the release of cell-free progeny virions at the end of the infectious cycle. This activity was observed in multiple cellular contexts including Vero cells and immortalized human keratinocytes. In the absence of gC, progeny virions bound more tightly to infected cells, suggesting that gC promotes the detachment of virions from the infected cell surface. Given this finding, we analyzed the biochemical interactions that tether progeny virions to cells and report evidence for two distinct modes of binding. One is consistent with a direct interaction between gC and HSPG, whereas the other is gC-independent and likely does not involve HSPG. Together, our results i) identify a novel function for a long-studied HSV-1 glycoprotein, and ii) demonstrate that the extracellular release of HSV-1 virions is a dynamic process involving multiple viral and host components.
Topics: Viral Envelope Proteins; Herpesvirus 1, Human; Humans; Chlorocebus aethiops; Vero Cells; Animals; Virion; Virus Release; Heparan Sulfate Proteoglycans; Keratinocytes
PubMed: 38805801
DOI: 10.1016/j.virol.2024.110120 -
PLoS Pathogens May 2024Marek's disease virus (MDV) vaccines were the first vaccines that protected against cancer. The avirulent turkey herpesvirus (HVT) was widely employed and protected...
Marek's disease virus (MDV) vaccines were the first vaccines that protected against cancer. The avirulent turkey herpesvirus (HVT) was widely employed and protected billions of chickens from a deadly MDV infection. It is also among the most common vaccine vectors providing protection against a plethora of pathogens. HVT establishes latency in T-cells, allowing the vaccine virus to persist in the host for life. Intriguingly, the HVT genome contains telomeric repeat arrays (TMRs) at both ends; however, their role in the HVT life cycle remains elusive. We have previously shown that similar TMRs in the MDV genome facilitate its integration into host telomeres, which ensures efficient maintenance of the virus genome during latency and tumorigenesis. In this study, we investigated the role of the TMRs in HVT genome integration, latency, and reactivation in vitro and in vivo. Additionally, we examined HVT infection of feather follicles. We generated an HVT mutant lacking both TMRs (vΔTMR) that efficiently replicated in cell culture. We could demonstrate that wild type HVT integrates at the ends of chromosomes containing the telomeres in T-cells, while integration was severely impaired in the absence of the TMRs. To assess the role of TMRs in vivo, we infected one-day-old chickens with HVT or vΔTMR. vΔTMR loads were significantly reduced in the blood and hardly any virus was transported to the feather follicle epithelium where the virus is commonly shed. Strikingly, latency in the spleen and reactivation of the virus were severely impaired in the absence of the TMRs, indicating that the TMRs are crucial for the establishment of latency and reactivation of HVT. Our findings revealed that the TMRs facilitate integration of the HVT genome into host chromosomes, which ensures efficient persistence in the host, reactivation, and transport of the virus to the skin.
Topics: Animals; Chickens; Telomere; Virus Integration; Marek Disease; Virus Latency; Genetic Vectors; Herpesvirus 1, Meleagrid; Marek Disease Vaccines; Genome, Viral; Herpesvirus 2, Gallid; Repetitive Sequences, Nucleic Acid; Poultry Diseases
PubMed: 38805555
DOI: 10.1371/journal.ppat.1012261 -
Virology Journal May 2024Equine herpesvirus type 1 (EHV-1) is commonly associated with horse abortion. Currently, there are no reported cases of abortion resulting from EHV-1 infection in...
BACKGROUND
Equine herpesvirus type 1 (EHV-1) is commonly associated with horse abortion. Currently, there are no reported cases of abortion resulting from EHV-1 infection in donkeys.
RESULTS
This was the first survey-based study of Chinese donkeys. The presence of EHV-1 was identified by PCR. This survey was conducted in Chabuchar County, North Xinjiang, China, in 2020. A donkey EHV-1 strain (Chabuchar/2020) was successfully isolated in MDBK cells. Seventy-two of 100 donkey sera were able to neutralize the isolated EHV-1. Moreover, the ORF33 sequence of the donkey-origin EHV-1 Chabuchar/2020 strain showed high levels of similarity in both its nucleotide (99.7‒100%) and amino acid (99.5‒100%) sequences, with those of horse EHV-1 strains. EHV-1 Chabuchar/2020 showed significant consistency and was classified within cluster 1 of horse EHV-1 strains. Further, analysis of the expected ORF30 nucleotide sequence revealed that donkey EHV-1 strains contained guanine at position 2254, resulting in a change to aspartic acid at position 752 of the viral DNA polymerase. Therefore, these strains were classified as horse neuropathogenic strains. Lastly, a phylogenetic tree was constructed using the partial ORF68 nucleotide sequences, showing that the identified donkey EHV-1 strain and the EHV-1 strain found in aborted Yili horses in China comprised a novel independent VIII group.
CONCLUSION
This study showed the first isolation and identification of EHV-1 as an etiological agent of abortions in donkeys. Further analysis of the ORF33, ORF30, and ORF68 sequences indicated that the donkey EHV-1 contained the neuropathogenic genotype of strains in the VIII group. It is thus important to be aware of EHV-1 infection in the donkey population, even though the virus has only been identified in donkey abortions in China.
Topics: Animals; Equidae; Herpesvirus 1, Equid; China; Phylogeny; Herpesviridae Infections; Lung; Aborted Fetus; Female; DNA, Viral; Open Reading Frames; Sequence Analysis, DNA; Pregnancy; Polymerase Chain Reaction
PubMed: 38802935
DOI: 10.1186/s12985-024-02390-2 -
Virology Journal May 2024Herpes simplex virus type 1 (HSV-1) infection of the eyes results in herpes simplex keratitis (HSK), which has led to vision loss and even blindness in patients....
Herpes simplex virus type 1 (HSV-1) infection of the eyes results in herpes simplex keratitis (HSK), which has led to vision loss and even blindness in patients. However, the rate of drug resistance in HSV is on the rise; therefore, new antiviral agents with sufficient safety profiles must be developed. At present, we assessed the anti-HSV-1 activity of 502 natural compounds and their ability to reduce the HSV-1-induced cytopathic effect. We chose harmol for further studies because it exhibited the highest antiviral activity. We found that harmol inhibited both HSV-1 F and HSV-1/153 (a clinical drug-resistant strain) replication, with an EC of 9.34 µM and 5.84 µM, respectively. Moreover, harmol reduced HSV-1 replication in corneal tissues and viral progeny production in tears, and also alleviated early corneal surface lesions related to HSK. For example, harmol treatment preserved corneal thickness and nerve density in HSK mice. Interestingly, harmol also showed a promising antiviral effect on HSV-1/153 induced HSK in mouse model. Furthermore, harmol combined with acyclovir (ACV) treatment showed a greater antiviral effect than either one alone in vitro. Therefore, harmol may be a promising therapeutic agent for managing HSK.
Topics: Animals; Antiviral Agents; Keratitis, Herpetic; Mice; Herpesvirus 1, Human; Virus Replication; Disease Models, Animal; Acyclovir; Cornea; Chlorocebus aethiops; Humans; Female; Vero Cells; Mice, Inbred BALB C
PubMed: 38802860
DOI: 10.1186/s12985-024-02384-0 -
Viruses May 2024Marek's disease (MD), caused by (GaAHV2) or Marek's disease herpesvirus (MDV), is a devastating disease in chickens characterized by the development of lymphomas...
Marek's disease (MD), caused by (GaAHV2) or Marek's disease herpesvirus (MDV), is a devastating disease in chickens characterized by the development of lymphomas throughout the body. Vaccine strains used against MD include 3 (GaAHV3), a non-oncogenic chicken alphaherpesvirus homologous to MDV, and homologous meleagrid alphaherpesvirus 1 (MeAHV1) or turkey herpesvirus (HVT). Previous work has shown most of the MDV gC produced during in vitro passage is secreted into the media of infected cells although the predicted protein contains a transmembrane domain. We formerly identified two alternatively spliced gC mRNAs that are secreted during MDV replication in vitro, termed gC104 and gC145 based on the size of the intron removed for each (gC) transcript. Since gC is conserved within the subfamily, we hypothesized GaAHV3 (strain 301B/1) and HVT also secrete gC due to mRNA splicing. To address this, we collected media from 301B/1- and HVT-infected cell cultures and used Western blot analyses and determined that both 301B/1 and HVT produced secreted gC. Next, we extracted RNAs from 301B/1- and HVT-infected cell cultures and chicken feather follicle epithelial (FFE) skin cells. RT-PCR analyses confirmed one splicing variant for 301B/1 gC (gC104) and two variants for HVT gC (gC104 and gC145). Interestingly, the splicing between all three viruses was remarkably conserved. Further analysis of predicted and validated mRNA splicing donor, branch point (BP), and acceptor sites suggested single nucleotide polymorphisms (SNPs) within the 301B/1 transcript sequence resulted in no gC145 being produced. However, modification of the 301B/1 gC145 donor, BP, and acceptor sites to the MDV sequences did not result in gC145 mRNA splice variant, suggesting mRNA splicing is more complex than originally hypothesized. In all, our results show that mRNA splicing of avian herpesviruses is conserved and this information may be important in developing the next generation of MD vaccines or therapies to block transmission.
Topics: Animals; Chickens; RNA Splicing; Viral Envelope Proteins; RNA, Messenger; Marek Disease; Mardivirus; Viral Proteins; Herpesvirus 2, Gallid; Alternative Splicing; Antigens, Viral
PubMed: 38793663
DOI: 10.3390/v16050782 -
Viruses May 2024NUT (nuclear-protein-in-testis) carcinoma (NC) is a highly aggressive tumor disease. Given that current treatment regimens offer a median survival of six months only, it...
NUT (nuclear-protein-in-testis) carcinoma (NC) is a highly aggressive tumor disease. Given that current treatment regimens offer a median survival of six months only, it is likely that this type of tumor requires an extended multimodal treatment approach to improve prognosis. In an earlier case report, we could show that an oncolytic herpes simplex virus (T-VEC) is functional in NC patients. To identify further combination partners for T-VEC, we have investigated the anti-tumoral effects of T-VEC and five different small molecule inhibitors (SMIs) alone and in combination in human NC cell lines. Dual combinations were found to result in higher rates of tumor cell reductions when compared to the respective monotherapy as demonstrated by viability assays and real-time tumor cell growth monitoring. Interestingly, we found that the combination of T-VEC with SMIs resulted in both stronger and earlier reductions in the expression of c-Myc, a main driver of NC cell proliferation, when compared to T-VEC monotherapy. These results indicate the great potential of combinatorial therapies using oncolytic viruses and SMIs to control the highly aggressive behavior of NC cancers and probably will pave the way for innovative multimodal clinical studies in the near future.
Topics: Humans; Oncolytic Viruses; Oncolytic Virotherapy; Cell Line, Tumor; Combined Modality Therapy; Biological Products; Cell Proliferation; Oncogene Proteins; Nuclear Proteins; Carcinoma; Cell Survival; Proto-Oncogene Proteins c-myc; Antineoplastic Agents; Neoplasm Proteins; Herpesvirus 1, Human
PubMed: 38793657
DOI: 10.3390/v16050775 -
Viruses May 2024Based on several clinical observations it was hypothesized that herpesviruses may influence the replication of human bocaviruses, the second known parvoviruses that have...
Based on several clinical observations it was hypothesized that herpesviruses may influence the replication of human bocaviruses, the second known parvoviruses that have been confirmed as human pathogens. While several cell lines support the growth of HSV-1, HBoV-1 was exclusively cultivated on air-liquid interface cultures, the latter being a rather complicated, slow, and low throughput system. One of the cell lines are T84 cells, which are derived from the lung metastasis of a colorectal tumor. In this study, we provide evidence that T84 also supports HBoV replication when cultivated as monolayers, while simultaneously being permissive for HSV-1. The cell culture model thus would enable co-infection studies of both viruses and is worth being optimized for high throughput studies with HBoV-1. Additionally, the study provides evidence for a supporting effect of HSV-1 on the replication and packaging of HBoV-1 progeny DNA into DNase-resistant viral particles.
Topics: Herpesvirus 1, Human; Humans; Virus Replication; Coinfection; Human bocavirus; Cell Line; Cell Line, Tumor; Cell Culture Techniques; Herpes Simplex; Parvoviridae Infections; Chlorocebus aethiops; Virus Cultivation
PubMed: 38793654
DOI: 10.3390/v16050773 -
Viruses May 2024Our current understanding of HSV latency is based on a variety of clinical observations, and in vivo, ex vivo, and in vitro model systems, each with unique advantages... (Review)
Review
Our current understanding of HSV latency is based on a variety of clinical observations, and in vivo, ex vivo, and in vitro model systems, each with unique advantages and drawbacks. The criteria for authentically modeling HSV latency include the ability to easily manipulate host genetics and biological pathways, as well as mimicking the immune response and viral pathogenesis in human infections. Although realistically modeling HSV latency is necessary when choosing a model, the cost, time requirement, ethical constraints, and reagent availability are also equally important. Presently, there remains a pressing need for in vivo models that more closely recapitulate human HSV infection. While the current in vivo, ex vivo, and in vitro models used to study HSV latency have limitations, they provide further insights that add to our understanding of latency. In vivo models have shed light on natural infection routes and the interplay between the host immune response and the virus during latency, while in vitro models have been invaluable in elucidating molecular pathways involved in latency. Below, we review the relative advantages and disadvantages of current HSV models and highlight insights gained through each.
Topics: Virus Latency; Humans; Herpes Simplex; Animals; Simplexvirus; Herpesvirus 1, Human; Disease Models, Animal
PubMed: 38793628
DOI: 10.3390/v16050747 -
Viruses May 2024Equid herpesvirus 4 (EHV-4) is a common respiratory pathogen in horses. It sporadically induces abortion or neonatal death. Although its contribution in neurological...
Equid herpesvirus 4 (EHV-4) is a common respiratory pathogen in horses. It sporadically induces abortion or neonatal death. Although its contribution in neurological disorders is not clearly demonstrated, there is a strong suspicion of its involvement. Despite preventive treatments using vaccines against EHV-1/EHV-4, the resurgence of alpha-EHV infection still constitutes an important threat to the horse industry. Yet very few studies have been conducted on the search for antiviral molecules against EHV-4. A screening of 42 antiviral compounds was performed in vitro on equine fibroblast cells infected with the EHV-4 405/76 reference strain (VR2230). The formation of cytopathic effects was monitored by real-time cell analysis (RTCA), and the viral load was quantified by quantitative PCR. Aciclovir, the most widely used antiviral against alpha-herpesviruses in vivo, does not appear to be effective against EHV-4 in vitro. Potential antiviral activities were confirmed for eight molecules (idoxuridine, vidarabine, pritelivir, cidofovir, valganciclovir, ganciclovir, aphidicolin, and decitabine). Decitabine demonstrates the highest efficacy against EHV-4 in vitro. Transcriptomic analysis revealed the up-regulation of various genes implicated in interferon (IFN) response, suggesting that decitabine triggers the immune antiviral pathway.
Topics: Animals; Antiviral Agents; Horses; Decitabine; Immunity, Innate; Herpesvirus 4, Equid; Fibroblasts; Herpesviridae Infections; Horse Diseases; Viral Load; Cell Line; Virus Replication; Drug Evaluation, Preclinical
PubMed: 38793627
DOI: 10.3390/v16050746