•Merits of Herpesviridae as recombinant viral vectors.•Techniques and strategies applied for generating recombinant herpesviruses-based vaccine vectors.•Efficacy of members of Herpesviridae in ...vaccine development for combating animal pathogens.•Opinions and perspectives for improvement of recombinant viral vectors for vaccine development.
Throughout the past few decades, numerous viral species have been generated as vaccine vectors. Every viral vector has its own distinct characteristics. For example, the family herpesviridae encompasses several viruses that have medical and veterinary importance. Attenuated herpesviruses are developed as vectors to convey heterologous immunogens targeting several serious and crucial pathogens. Some of these vectors have already been licensed for use in the veterinary field. One of their prominent features is their capability to accommodate large amount of foreign DNA, and to stimulate both cell-mediated and humoral immune responses. A better understanding of vector-host interaction builds up a robust foundation for the future development of herpesviruses-based vectors. At the time, many molecular tools are applied to enable the generation of herpesvirus-based recombinant vaccine vectors such as BAC technology, homologous and two-step en passant mutagenesis, codon optimization, and the CRISPR/Cas9 system. This review article highlights the most important techniques applied in constructing recombinant herpesviruses vectors, advantages and disadvantages of each recombinant herpesvirus vector, and the most recent research regarding their use to control major animal diseases.
(1) Background: equid alphaherpesvirus-1 (EHV-1) is a highly contagious viral pathogen prevalent in most horse populations worldwide. Genome-editing technologies such as CRISPR/Cas9 have become ...powerful tools for precise RNA-guided genome modifications; (2) Methods: we designed single guide RNAs (sgRNA) to target three essential (ORF30, ORF31, and ORF7) and one non-essential (ORF74) EHV-1 genes and determine their effect on viral replication dynamics in vitro; (3) Results: we demonstrated that sgRNAs targeting essential lytic genes reduced EHV-1 replication, whereas those targeting ORF74 had a negligible effect. The sgRNAs targeting ORF30 showed the strongest effect on the suppression of EHV-1 replication, with a reduction in viral genomic copy numbers and infectious progeny virus output. Next-generation sequencing identified variants with deletions in the specific cleavage site of selective sgRNAs. Moreover, we evaluated the combination between different sgRNAs and found that the dual combination of sgRNAs targeting ORF30 and ORF7 significantly suppressed viral replication to lower levels compared to the use of a single sgRNA, suggesting a synergic effect; (4) Conclusion: data demonstrate that sgRNA-guided CRISPR/Cas9 can be used to inhibit EHV-1 replication in vitro, indicating that this programmable technique can be used to develop a novel, safe, and efficacious therapeutic and prophylactic approach against EHV-1.
Objective: In a prospective cohort study to evaluate the clinical and immunological efficacy of differentiated targeted interferon and immunomodulatory therapies focused on identified pathological ...immunophenotropes and associated clinical manifestations in immunocompromised patients suffering from atypical chronic active herpes viral infections (ACA-HVI). Materials and methods: 335 patients suffering from mixed-AHA-HVI were examined. The study complex included: methods for detecting herpesviruses: serodiagnosis, PCR-RV; immunological methods: a research of subpopulation of blood lymphocytes (method of a flow cytometry), determination of the spontaneous and induced products of IFNα and IFNγ, levels of serum cytokines and immunoglobulins (IL-1β, IL-6, IL-17, TNFα and IFNα and IFNγ, Ig A, M, G) by ELISA. The study was approved by the ethics board and informed consent was obtained from all patients. Results: Integral formulas of disorders in the antiviral immune defense system were created, which made it possible to isolate 3 pathological immunophenotypes (PIF): PIF1: NG↓+ind.IFNα/IFNγ↓+CTL↓+EKK↓+IgM↑+hypecytokinemiya (IL-1β↑+IL-6↑+TNFα↑); PIF2: NG↓+ ind. IFNα/IFNγ↓ + EKK↓+ IgG↓+hypercytokinemiya (IL-1β↑+IL-6↑+TNFα↑) and PIF3: NG↓+ind.IFNα/IFNγ↓+hypercytokinemiya (IL-1β↑+IL- 6↑+TNFα↑). Taking into account the identified disorders, a program of targeted interferon and immunomodulatory therapy was developed for each PIF: local and systemic IFN therapy + hexapeptide was developed for PIF1; for PIF2- local and systemic IFN therapy + glucosaminimuramyldipeptide; for PIF3-local and systemic IFN therapy. Conclusions: High clinical efficacy was demonstrated in 100% of patients with three groups of ACA-HVI. Immunological effectiveness of targeted interferon and immunomodulatory therapy programs: 89.5% for PIF1; for PIF2-57.6% and for PIF3- 37.5% of cases.
Equid herpesviruses (EHVs) are a group of highly impactful viral pathogens that affect horses, presenting a substantial risk to the global equine industry. Among these, equid herpesvirus-1 (EHV-1) ...primarily causes respiratory infections. However, its ability to spread to distant organs can lead to severe consequences such as abortion and neurological diseases. These viruses can enter a dormant phase, with minimal activity, and later reactivate to trigger active infections at any time. Recently, there has been a notable rise in the prevalence of a particularly devastating strains of EHV-1 known as equid herpesviral myeloencephalopathy (EHM). In the light of dynamic nature of EHV-1, this review provides a thorough overview of EHV-1 and explores how advances in viral biology affect the pathophysiology of viral infection. The information presented here is crucial for understanding the dynamics of EHV-1 infections and creating practical plans to stop the virus's global spread among equid populations.
•Equine herpesviruses (EHVs) are a group of highly impactful viral pathogens of equines.•Recently, a strain of EHV-1 reported to cause equine herpes viral myeloencephalopathy (EHM).•We highlight advancements in EHV and EHM management in horses.•Dynamics of EHV-1 infections and strategies to control its spread are discussed.•We emphasis the monitoring of recombinant strain of EHV-1 in equines.
Interferons limit viral replication by inducing intracellular restriction factors, such as the GTPase MxB (also designated MX2), which inhibits HIV-1 and, as recently shown, herpesviruses. Inhibition ...of these viruses occurs at ill-defined steps after viral entry and requires formation of MxB dimers or oligomers, but GTP hydrolysis is needed only for blocking herpesviruses. Together with previous findings on related MxA, the new research on MxB highlights the mechanistic diversity by which MX proteins interfere with viral replication.
The tetraspanin protein CD63 has been recently described as a key factor in extracellular vesicle (EV) production and endosomal cargo sorting. In the context of Epstein-Barr virus (EBV) infection, ...CD63 is required for the efficient packaging of the major viral oncoprotein latent membrane protein 1 (LMP1) into exosomes and other EV populations and acts as a negative regulator of LMP1 intracellular signaling. Accumulating evidence has also pointed to intersections of the endosomal and autophagy pathways in maintaining cellular secretory processes and as sites for viral assembly and replication. Indeed, LMP1 can activate the mammalian target of rapamycin (mTOR) pathway to suppress host cell autophagy and facilitate cell growth and proliferation. Despite the growing recognition of cross talk between endosomes and autophagosomes and its relevance to viral infection, little is understood about the molecular mechanisms governing endosomal and autophagy convergence. Here, we demonstrate that CD63-dependent vesicle protein secretion directly opposes intracellular signaling activation downstream of LMP1, including mTOR-associated proteins. Conversely, disruption of normal autolysosomal processes increases LMP1 secretion and dampens signal transduction by the viral protein. Increases in mTOR activation following CD63 knockout are coincident with the development of serum-dependent autophagic vacuoles that are acidified in the presence of high LMP1 levels. Altogether, these findings suggest a key role of CD63 in regulating the interactions between endosomal and autophagy processes and limiting cellular signaling activity in both noninfected and virally infected cells.
The close connection between extracellular vesicles and viruses is becoming rapidly and more widely appreciated. EBV, a human gamma herpesvirus that contributes to the progression of a multitude of lymphomas and carcinomas in immunocompromised or genetically susceptible populations, packages its major oncoprotein, LMP1, into vesicles for secretion. We have recently described a role of the host cell protein CD63 in regulating intracellular signaling of the viral oncoprotein by shuttling LMP1 into exosomes. Here, we provide strong evidence of the utility of CD63-dependent EVs in regulating global intracellular signaling, including mTOR activation by LMP1. We also demonstrate a key role of CD63 in coordinating endosomal and autophagic processes to regulate LMP1 levels within the cell. Overall, this study offers new insights into the complex intersection of cellular secretory and degradative mechanisms and the implications of these processes in viral replication.
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