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ABSTRACT Background Methods Results Conclusions Mpox (formerly known as monkeypox), a zoonotic disease caused by Monkeypox virus (MPXV), has become an international outbreak since May 2022. Mpox often presents with a mild systemic illness and a characteristic vesiculopustular skin eruption. In addition to molecular testing, histopathology of cutaneous lesions usually shows distinctive findings, such as epidermal necrosis, balloon degeneration, papillary dermal edema, and focal dermal necrosis, which have proven helpful in the diagnosis of mpox. Viral cytopathic changes with areas of multinucleation, smudging of the nuclei, and intracytoplasmic inclusions have also been described. Although useful, these features are relatively nonspecific. The use of a monoclonal antibody for immunohistochemical (IHC) staining of MPXV may be a useful tool in confirming mpox infection.Three cases of PCR‐confirmed mpox were biopsied and subjected to IHC staining with a monoclonal MPXV‐specific antibody targeting viral envelope protein A29. As controls, cell lines transduced to express other MPXV viral antigens and samples of cutaneous viral infections involving Molluscum contagiosum, Herpes simplex, Herpes zoster, or Cytomegalovirus were also subjected to IHC staining with this antibody.All three mpox patient biopsies performed on lesional skin subjected to MPXV IHC staining reliably detected viral infection in lesional skin with a diffuse cytoplasmic and focally nuclear staining pattern. No staining was seen in transduced cell lines expressing off‐target MPXV viral antigens and in lesional skin of other common viral infections listed above.The monoclonal MPXV‐specific antibody may be used as an adjunct tool to confirm mpox infection. [ABSTRACT FROM AUTHOR]

ABSTRACT Unexpected mass mortality of black bullhead Ameiurus melas (Rafinesque, 1820) fingerlings occurred 1 week after their arrival at our animal facility. The specimens of the invasive fish species originated from Lake Balaton, the largest natural freshwater lake in Hungary. The mortality reached 100% within 3 days. Gross pathological examination detected inflammation in the inner organs, renomegaly, and a marble, pale pink liver. Two pathogenic bacteria strains, Vibrio cholerae Pacini, 1854, and Plesiomonas shigelloides (Bader 1954), were detected in the fish liver examined. The molecular virological examination showed the presence of the nucleic acid of two dsDNA viruses. One is the Ictalurid herpesvirus 2 (IcHV‐2), which is a well‐known pathogen of the black bullhead that has only been reported from Italian fish farms previously. This is the first report of IcHV‐2 from a natural freshwater habitat. The other viral DNA detected in fish belongs to an unidentified virus species. Sequence analysis of the partial DNA polymerase gene confirmed that the novel virus is a member of the subfamily Chordopoxvirinae within the family Poxviridae. Although the causative agent of this mass mortality could not be identified with certainty, the clinical signs suggest that the detected viruses are the most suspicious. Furthermore, our results highlight that the health monitoring of invasive species is also important for the timely detection of pathogens that threaten the native fish fauna. [ABSTRACT FROM AUTHOR]

Amsacta moorei entomopoxvirus (AMEV) is a poxvirus exclusively infecting insects and has been considered as a potential biological control agent. AMEV includes a CPD photolyase (AMV025, AMEV photolyase gene) responsible for converting cyclobutane pyrimidine dimers (CPDs) back into monomers. The codon usage patterns and their influence on the evolution of the AMEV photolyase gene are still widely uninvestigated. Here, we conducted a thorough examination of the codon usage bias (CUB) within the photolyase gene of AMEV and contrasted it with that of the photolyase genes found in five other entomopoxvirus species. Both nucleotide content and relative synonymous codon usage (RSCU) analysis indicated a higher frequency of AT-ending codons in the photolyase gene of AMEV. The effective number of codons (ENC) analysis revealed a high CUB in AMEV photolyase gene. The ENC-GC3s plot, neutrality plot, parity rule 2, correspondence analysis, and correlation analysis collectively indicated that both natural selection and mutation pressure impact the codon usage patterns of the AMEV photolyase gene, with natural selection emerging as the dominant factor shaping these patterns. Our research represents the inaugural effort to assess the codon usage pattern of the photolyase gene in AMEV, aiming to enhance our comprehension of the evolutionary dynamics within an entomopoxvirus. [ABSTRACT FROM AUTHOR]

As the world still vividly recalls the previous monkeypox (mpox) outbreak that impacted over 120 countries worldwide with more than 99,000 cases in 2022, we are now facing a second wave of infections from the monkeypox virus (MPXV), characterized by an exponential increase in cases. The current 2024 outbreak has already recorded more than 20,000 cases in Africa, marking a dramatic escalation compared to previous outbreaks. The predominance of the newly identified clade Ib variant, first detected in the Democratic Republic of the Congo (DRC) and now identified across multiple African nations and beyond, underscores its enhanced transmissibility and potential for international spread, evidenced by cases in Sweden and Thailand. The World Health Organization (WHO) declared on August 14, 2024, the current mpox outbreak a Public Health Emergency of International Concern (PHEIC), calling for heightened global public health measures. The ongoing pattern of unusual, frequent, and extensive outbreaks of mpox with potential global implications poses significant questions. This review addresses, in the format of 50 questions and answers, the 2024 mpox outbreak, detailing its characteristics, epidemiological data, and impact compared to previous outbreaks. It comprehensively explores critical questions related to MPXV virological characteristics, immunological response, clinical manifestations, epidemiology, diagnostics, and available treatments. The review also documents the significant and evolving challenges posed by the current mpox outbreak, highlighting its scale, spread, and public health response. [ABSTRACT FROM AUTHOR]

Fatty acid metabolism can provide various products essential for viral infections. How vaccinia virus (VACV), the prototype of poxviruses, modulates fatty acid metabolism is not well understood. Here, we show that VACV infection results in increased neutral lipid droplet synthesis, the organelles that play a crucial role in storing and mobilizing fatty acids for energy production via ß-oxidation. Citrate is the first tricarboxylic acid (TCA) cycle intermediate that can be transported to the cytosol to be converted to acetyl-CoA for de novo fatty acid biosynthesis. We found that VACV infection stimulates the S455 phosphorylation of ATP citrate lyase (ACLY), a pivotal enzyme that links citrate metabolism with lipid metabolism. We demonstrate that the inhibition of neutral lipid droplet synthesis and ACLY severely suppresses VACV replication. Remarkably, we found that virus growth factor (VGF)-induced signaling is essential for the VACV-mediated upregulation of ACLY phosphorylation and neutral lipid droplets. Finally, we report that VGF-induced EGFR-Akt pathway and ACLY phosphorylation are important for VACV stimulation of neutral lipid synthesis. These findings identified a new way of rewiring cell metabolism by a virus and a novel function for VGF in the governance of virus-host interactions through the induction of a key enzyme at the crossroads of the TCA cycle and fatty acid metabolism. Our study also provides a mechanism for the role played by VGF and its downstream signaling cascades in the modulation of lipid metabolism in VACV-infected cells. IMPORTANCE Neutral lipid droplets are vital players in cellular metabolism. Here, we showed that VACV induces neutral lipid droplet synthesis in infected primary human foreskin fibroblasts and identified the cellular and viral factors needed. We ident ified VACV encoded growth factor (VGF) as an essential viral factor that induces cellular EGFR-Akt signaling to increase lipid droplets. Interestingly, VACV increases the S455 phosphorylation of ACLY, a key metabolic enzyme that sits at the crossroads of carbohydrate and lipid metabolism in a VGF-EGFR-Akt-dependent manner. We also found that ACLY is vital for VACV-induced lipid droplet synthesis. Our findings ident ified the modulation of ACLY by a virus and identified it as a potential target for antiviral development against pathogenic poxviruses. Our study also expands the role of growth factor signaling in boosting VACV replication by targeting fatty acid metabolism. [ABSTRACT FROM AUTHOR]

The antiviral protein kinase R (PKR) is activated by viral double-stranded RNA and phosphorylates translation initiation factor eIF2a, thereby inhibiting translation and virus replication. Most poxviruses contain two PKR inhibitors, called E3 and K3 in vaccinia virus (VACV), which are determinants of viral host range. The prevailing model for E3 function is that it inhibits PKR through the non-specific sequestration of double-stranded (ds) RNA. Our data revealed that Syrian hamster PKR was resistant to E3, which is at odds with the sequestration model. However, Syrian hamster PKR was still sensitive to K3 inhibition. In contrast, Armenian hamster PKR showed opposite sensitivities, being sensitive to E3 and resistant to K3 inhibition. Mutational analyses of hamster PKRs showed that sensitivity to E3 inhibition was largely determined by the region linking the dsRNA-binding domains and the kinase domain of PKR, whereas two amino acid residues in the kinase domain (helix aG) determined sensitivity to K3. The expression of PKRs in congenic cells showed that Syrian hamster PKR containing the two Armenian hamster PKR residues in helix aG was resistant to wild-type VACV infection and that cells expressing either hamster PKR recapitulated the phenotypes observed in species-derived cell lines. The observed resistance of Syrian hamster PKR to E3 explains its host range function and challenges the paradigm that dsRNA-binding PKR inhibitors mainly act by the sequestration of dsRNA. IMPORTANCE The molecular mechanisms that govern the host range of viruses are incompletely understood. We show that the host range functions of E3 and K3, two host range factors from vaccinia virus, are a result of species-specific interactions with the antiviral protein kinase R (PKR) and that PKR from closely related species displayed dramatic differences in their sensitivities to these viral inhibitors. The current model for E3-mediated PKR inhibition is that E3 non-specifically sequesters double-stranded (ds) RNA to prevent PKR activation. This model does not predict species-specific sensitivity to E3; therefore, our data suggest that the current model is incomplete and that dsRNA sequestration is not the primary mechanism for E3 activity. [ABSTRACT FROM AUTHOR]

The Africa Centers for Disease Control and Prevention declared mpox a Public Health Emergency of Continental Security (PHECS) in Africa. African public health systems have moved to mobilize a response against a backdrop of inherent significant challenges. With this commentary, we discuss how lessons from past public health emergencies, particularly COVID-19 and Ebola outbreaks, have prepared the region for improved disease surveillance, rapid response strategies, and effective public health communication and how these lessons can be applied to the mpox response, emphasizing the importance of strong healthcare infrastructure, effective data sharing, community engagement, targeted interventions, and robust contact tracing. Additionally, addressing misinformation and building public trust are crucial for controlling the spread of any disease. By leveraging these strategies, African countries can enhance their response to mpox. This includes improving diagnostic capabilities, strengthening cross-border collaborations, and prioritizing vaccination campaigns where needed. Ultimately, by applying the hard-earned lessons from the COVID-19 pandemic and Ebola outbreak, the East Africa region can better address the challenges posed by mpox and safeguard public health. [ABSTRACT FROM AUTHOR]

In eukaryotic cells, the endoplasmic reticulum is particularly important in post-translational modification of proteins before they are released extracellularly or sent to another endomembrane system. The correct three-dimensional folding of most proteins occurs in the ER lumen, which has an oxidative environment that is essential for the formation of disulfide bridges, which are important in maintaining protein structure. The ER is a versatile organelle that ensures the correct structure of proteins and is essential in the synthesis of lipids and sterols, in addition to offering support in the maintenance of intracellular calcium. Consequently, the cells needed to respond to demands caused by physiological conditions and pathological disturbances in the organelle homeostasis, leading to proper functioning of the cell or even programmed cell death. Disturbances to the ER function trigger a response to the accumulation of unfolded or misfolded proteins, known as the unfolded protein response. Such disturbances include abiotic stress, pharmacological agents, and intracellular pathogens, such as viruses. When misfolded proteins accumulate in the ER, they can undergo ubiquitination and proteasomal degradation through components of the ER-associated degradation system. Once a prolonged activity of the UPR pathway occurs, indicating that homeostasis cannot be reestablished, components of this pathway induce cell death by apoptosis. Here, we discuss how viruses have evolved ways to counteract UPR responses to maximize replication. This evolutionary viral ability is important to understand cell pathology and should be taken into account when designing therapeutic interventions and vaccines. [ABSTRACT FROM AUTHOR]

Parasitoid wasps are one of the most species‐rich groups of animals on Earth, due to their ability to successfully develop as parasites of nearly all types of insects. Unlike most known parasitoid wasps that specialize towards one or a few host species, Diachasmimorpha longicaudata is a generalist that can survive within multiple genera of tephritid fruit fly hosts, including many globally important pest species. Diachasmimorpha longicaudata has therefore been widely released to suppress pest populations as part of biological control efforts in tropical and subtropical agricultural ecosystems. In this study, we investigated the role of a mutualistic poxvirus in shaping the host range of D. longicaudata across three genera of agricultural pest species: two of which are permissive hosts for D. longicaudata parasitism and one that is a nonpermissive host. We found that permissive hosts Ceratitis capitata and Bactrocera dorsalis were highly susceptible to manual virus injection, displaying rapid virus replication and abundant fly mortality. However, the nonpermissive host Zeugodacus cucurbitae largely overcame virus infection, exhibiting substantially lower mortality and no virus replication. Investigation of transcriptional dynamics during virus infection demonstrated hindered viral gene expression and limited changes in fly gene expression within the nonpermissive host compared with the permissive species, indicating that the host range of the viral symbiont may influence the host range of D. longicaudata wasps. These findings also reveal that viral symbiont activity may be a major contributor to the success of D. longicaudata as a generalist parasitoid species and a globally successful biological control agent. [ABSTRACT FROM AUTHOR]

Microtubule (MT)-dependent transport is a critical means of intracellular movement of cellular cargo by kinesin and dynein motors. MT-dependent transport is tightly regulated by cellular MT-associated proteins (MAPs) that directly bind to MTs and either promote or impede motor protein function. Viruses have been widely shown to usurp MT-dependent transport to facilitate their virion movement to sites of replication and/or for exit from the cell. However, it is unclear if viruses also negatively regulate MT-dependent transport. Using single-molecule motility and cellular transport assays, we show that the vaccinia virus (VV)-encoded MAP, A51R, inhibits kinesin-1-dependent transport along MTs in vitro and in cells. This inhibition is selective as the function of kinesin-3 is largely unaffected by VV A51R. Interestingly, we show that A51R promotes the perinuclear accumulation of cellular cargo transported by kinesin-1 such as lysosomes and mitochondria during infection. Moreover, A51R also regulates the release of specialized VV virions that exit the cell using kinesin-1-dependent movement. Using a fluorescently tagged rigor mutant of kinesin-1, we show that these motors accumulate on A51R-stabilized MTs, suggesting these stabilized MTs may form a "kinesin-1 sink" to regulate MT-dependent transport in the cell. Collectively, our findings uncover a new mechanism by which viruses regulate host cytoskeletal processes. [ABSTRACT FROM AUTHOR]

Mpox (monkeypox) is a neglected tropical disease that has received increased attention since the multi-nation outbreak that began in 2022. The virus is endemic in West and Central Africa, where the Democratic Republic of the Congo (DRC) is the most affected country. Clade I monkeypox virus (MPXV) infection is endemic in the DRC and has an overall case fatality rate of 10.6% among children and adults. A study conducted in Sankuru Province, DRC, from 2007 to 2011 demonstrated that 75% of pregnant women with mpox had miscarriages or stillbirth. Further analysis of a stillborn fetus showed that MPXV could infect both the placenta and fetus, causing congenital infection. No additional cases of Clade I MPXV in pregnant women were reported until a new outbreak occurred in South Kivu Province during 2023 and 2024. Eight pregnant women having Clade I MPXV infection were identified, of whom four had either miscarriages or stillbirth, representing a 50% fetal mortality rate. These reports confirm previous data from the DRC that indicate the capability of Clade I MPXV to affect the fetus, causing congenital infection and fetal loss in a high percentage of cases. In this article, we review both past and new data from the DRC on the effects of Clade I MPXV during pregnancy and discuss the association of mpox with fetal loss. [ABSTRACT FROM AUTHOR]

The skin is a complex tissue that provides a strong physical barrier against invading pathogens. Despite this, many viruses can access the skin and successfully replicate in either the epidermal keratinocytes or dermal immune cells. In this review, we provide an overview of the antiviral T cell biology responding to cutaneous viral infections and how these responses differ depending on the cellular targets of infection. Much of our mechanistic understanding of T cell surveillance of cutaneous infection has been gained from murine models of poxvirus and herpesvirus infection. However, we also discuss other viral infections, including flaviviruses and papillomaviruses, in which the cutaneous T cell response has been less extensively studied. In addition to the mechanisms of successful T cell control of cutaneous viral infection, we highlight knowledge gaps and future directions with possible impact on human health. [ABSTRACT FROM AUTHOR]

Lumpy skin disease virus (LSDV) is a member of the capripoxvirus (CPPV) genus of the Poxviridae family. LSDV is a rapidly emerging, high-consequence pathogen of cattle, recently spreading from Africa and the Middle East into Europe and Asia. We have sequenced the whole genome of historical LSDV isolates from the Pirbright Institute virus archive, and field isolates from recent disease outbreaks in Sri Lanka, Mongolia, Nigeria and Ethiopia. These genome sequences were compared to published genomes and classified into different subgroups. Two subgroups contained vaccine or vaccine-like samples ("Neethling-like" clade 1.1 and "Kenya-like" subgroup, clade 1.2.2). One subgroup was associated with outbreaks of LSD in the Middle East/Europe (clade 1.2.1) and a previously unreported subgroup originated from cases of LSD in west and central Africa (clade 1.2.3). Isolates were also identified that contained a mix of genes from both wildtype and vaccine samples (vaccine-like recombinants, grouped in clade 2). Whole genome sequencing and analysis of LSDV strains isolated from different regions of Africa, Europe and Asia have provided new knowledge of the drivers of LSDV emergence, and will inform future disease control strategies. [ABSTRACT FROM AUTHOR]

A juvenile grey‐headed flying fox (GHFF) (Pteropus poliocephalus) presented to the Australia Zoo Wildlife Hospital after a wildlife carer found the animal hanging on the outside of an aviary. On presentation, the animal was emaciated and moribund with disseminated, multifocal, depigmented and proliferative lesions on the wing membranes and skin of the neck. Histopathology revealed multiple, well‐circumscribed proliferative epidermal lesions with intracytoplasmic inclusion bodies. A poxvirus was identified via transmission electron microscopy and next‐generation sequencing (NGS). Analysis of sequences obtained demonstrated 99% nucleotide identity to Pteropox virus strain Australia (GenBank KU980965). To the authors' knowledge, this paper describes the first case of Pteropox virus infection in a GHFF. [ABSTRACT FROM AUTHOR]

Poxviruses have evolved a wide array of mechanisms to evade the immune response, and we provide an overview of the different immunomodulatory strategies. Poxviruses prevent the recognition of viral DNA that triggers the immune responses and inhibit signaling pathways within the infected cell. A unique feature of poxviruses is the production of secreted proteins that mimic cytokines and cytokine receptors, acting as decoy receptors to neutralize the activity of cytokines and chemokines. The capacity of these proteins to evade cellular immune responses by inhibiting cytokine activation is complemented by poxviruses' strategies to block natural killer cells and cytotoxic T cells, often through interfering with antigen presentation pathways. Mechanisms that target complement activation are also encoded by poxviruses. Virus-encoded proteins that target immune molecules and pathways play a major role in immune modulation, and their contribution to viral pathogenesis, facilitating virus replication or preventing immunopathology, is discussed. [ABSTRACT FROM AUTHOR]

Myxoma virus (MYXV) is a Leporipoxvirus (genus) belonging to the family Poxviridae; it is characterised by a genome of approximately 161 kb dsDNA encoding for several proteins that play an essential role in both host spectrum determination and immunomodulation. The healthy reservoir of the virus is Sylvilagus spp. At the same time, in wild and domestic European rabbits (Oryctolagus cuniculus), MYXV is the etiologic agent of myxomatosis, a disease with an extremely high mortality rate. In 2014, an interspecies jump of MYXV was reported in Lepus europaeus in the UK. In 2018, myxomatosis induced by a new recombinant strain called MYXV-To was identified during a large outbreak in Iberian hares (Lepus granatensis) in Spain. Here, we describe the case of myxomatosis in another hare species: an adult male Italian hare (Lepus corsicanus) found dead in 2018 in Sicily with lesions suggestive of myxomatosis and treponema infection. Laboratory tests, e.g., end-point PCR and negative staining electron microscopy, confirmed the presence of both pathogens. MYXV was then isolated from tissue samples in permissive cells and sequenced using NGS technology. Main genomic differences concerning known MYXV strains are discussed. [ABSTRACT FROM AUTHOR]

Infection at barrier sites, e.g., skin, activates local immune defenses that limit pathogen spread, while preserving tissue integrity. Phenotypically distinct γδ T cell populations reside in skin, where they shape immunity to cutaneous infection prior to onset of an adaptive immune response by conventional αβ CD4+ (TCD4+) and CD8+ (TCD8+) T cells. To examine the mechanisms used by γδ T cells to control cutaneous virus replication and tissue pathology, we examined γδ T cells after infection with vaccinia virus (VACV). Resident γδ T cells expanded and combined with recruited γδ T cells to control pathology after VACV infection. However, γδ T cells did not play a role in control of local virus replication or blockade of systemic virus spread. We identified a unique wound healing signature that has features common to, but also features that antagonize, the sterile cutaneous wound healing response. Tissue repair generally occurs after clearance of a pathogen, but viral wound healing started prior to the peak of virus replication in the skin. γδ T cells contributed to wound healing through induction of multiple cytokines/growth factors required for efficient wound closure. Therefore, γδ T cells modulate the wound healing response following cutaneous virus infection, maintaining skin barrier function to prevent secondary bacterial infection. [ABSTRACT FROM AUTHOR]

The sudden emergence of SARS-CoV-2 demonstrates the need for new vaccines that rapidly protect in the case of an emergency. In this study, we developed a recombinant MVA vaccine co-expressing SARS-CoV-2 prefusion-stabilized spike protein (ST) and SARS-CoV-2 nucleoprotein (N, MVA-SARS-2-ST/N) as an approach to further improve vaccine-induced immunogenicity and efficacy. Single MVA-SARS-2-ST/N vaccination in K18-hACE2 mice induced robust protection against lethal respiratory SARS-CoV-2 challenge infection 28 days later. The protective outcome of MVA-SARS-2-ST/N vaccination correlated with the activation of SARS-CoV-2-neutralizing antibodies (nABs) and substantial amounts of SARS-CoV-2-specific T cells especially in the lung of MVA-SARS-2-ST/N-vaccinated mice. Emergency vaccination with MVA-SARS-2-ST/N just 2 days before lethal SARS-CoV-2 challenge infection resulted in a delayed onset of clinical disease outcome in these mice and increased titers of nAB or SARS-CoV-2-specific T cells in the spleen and lung. These data highlight the potential of a multivalent COVID-19 vaccine co-expressing S- and N-protein, which further contributes to the development of rapidly protective vaccination strategies against emerging pathogens. [ABSTRACT FROM AUTHOR]

Vaccinia virus (Orthopoxvirus) F17 protein is a major virion structural phosphoprotein having a molecular weight of 11 kDa. Recently, it was shown that F17 synthesised in infected cells interacts with mTOR subunits to evade cell immunity and stimulate late viral protein synthesis. Several years back, we purified an 11 kDa protein that inhibited protein synthesis in reticulocyte lysate from virions, and that possesses all physico-chemical properties of F17 protein. To investigate this discrepancy, we used defective vaccinia virus particles devoid of the F17 protein (designated iF17− particles) to assess their ability to inhibit protein synthesis. To this aim, we purified iF17− particles from cells infected with a vaccinia virus mutant which expresses F17 only in the presence of IPTG. The SDS-PAGE protein profiles of iF17− particles or derived particles, obtained by solubilisation of the viral membrane, were similar to that of infectious iF17 particles. As expected, the profiles of full iF17− particles and those lacking the viral membrane were missing the 11 kDa F17 band. The iF17− particles did attach to cells and injected their viral DNA into the cytoplasm. Co-infection of the non-permissive BSC40 cells with a modified vaccinia Ankara (MVA) virus, expressing an mCherry protein, and iF17− particles, induced a strong mCherry fluorescence. Altogether, these experiments confirmed that the iF17− particles can inject their content into cells. We measured the rate of protein synthesis as a function of the multiplicity of infection (MOI), in the presence of puromycin as a label. We showed that iF17− particles did not inhibit protein synthesis at high MOI, by contrast to the infectious iF17 mutant. Furthermore, the measured efficiency to inhibit protein synthesis by the iF17 mutant virus generated in the presence of IPTG, was threefold to eightfold lower than that of the wild-type WR virus. The iF17 mutant contained about threefold less F17 protein than wild-type WR. Altogether these results strongly suggest that virion-associated F17 protein is essential to mediate a stoichiometric inhibition of protein synthesis, in contrast to the late synthesised F17. It is possible that this discrepancy is due to different phosphorylation states of the free and virion-associated F17 protein. [ABSTRACT FROM AUTHOR]

In the spring of 2022, an epidemic due to human monkeypox virus (MPXV) of unprecedented magnitude spread across all continents. Although this event was surprising in its suddenness, the resurgence of a virus from the Poxviridae family is not surprising in a world population that has been largely naïve to these viruses since the eradication of the smallpox virus in 1980 and the concomitant cessation of vaccination. Since then, a vaccine and two antiviral compounds have been developed to combat a possible return of smallpox. However, the use of these treatments during the 2022 MPXV epidemic showed certain limitations, indicating the importance of continuing to develop the therapeutic arsenal against these viruses. For several decades, efforts to understand the molecular mechanisms involved in the synthesis of the DNA genome of these viruses have been ongoing. Although many questions remain unanswered up to now, the three-dimensional structures of essential proteins, and in particular of the DNA polymerase holoenzyme in complex with DNA, make it possible to consider the development of a model for poxvirus DNA replication. In addition, these structures are valuable tools for the development of new antivirals targeting viral genome synthesis. This review will first present the molecules approved for the treatment of poxvirus infections, followed by a review of our knowledge of the replication machinery of these viruses. Finally, we will describe how these proteins could be the target of new antiviral compounds. [ABSTRACT FROM AUTHOR]

Smallpox was a highly contagious disease caused by the variola virus. The disease affected millions of people over thousands of years and variola virus ranked as one of the deadliest viruses in human history. The complete eradication of smallpox in 1980, a major triumph in medicine, was achieved through a global vaccination campaign using a less virulent poxvirus, vaccinia virus. Despite this success, the herd immunity established by this campaign has significantly waned, and concerns are rising about the potential reintroduction of variola virus as a biological weapon or the emergence of zoonotic poxviruses. These fears were further fueled in 2022 by a global outbreak of monkeypox virus (mpox), which spread to over 100 countries, thereby boosting interest in developing new vaccines using molecular approaches. However, poxviruses are complex and creating modern vaccines against them is challenging. This review focuses on the structural biology of the six major neutralization determinants on poxviruses (D8, H3, A27, L1, B5, and A33), the localization of epitopes targeted by neutralizing antibodies, and their application in the development of subunit vaccines. [ABSTRACT FROM AUTHOR]

The 2022 global Mpox outbreak swiftly introduced unforeseen diversity in the monkeypox virus (MPXV) population, resulting in numerous Clade IIb sublineages. This propagation of new MPXV mutations warrants the thorough re-investigation of previously recommended or validated primers designed to target MPXV genomes. In this study, we explored 18 PCR primer sets and examined their binding specificity against 5210 MPXV genomes, representing all the established MPXV lineages. Our results indicated that only five primer sets resulted in almost all perfect matches against the targeted MPXV lineages, and the remaining primer sets all contained 1–2 mismatches against almost all the MPXV lineages. We further investigated the mismatched primer-genome pairs and discovered that some of the primers overlapped with poorly sequenced and assembled regions of the MPXV genomes, which are consistent across multiple lineages. However, we identified 173 99% genome-wide conserved regions across all 5210 MPXV genomes, representing 30 lineages/clades with at least 80% lineage-specific consensus for future primer development and primer binding evaluation. This exercise is crucial to ensure that the current detection schemes are robust and serve as a framework for primer evaluation in clinical testing development for other infectious diseases. [ABSTRACT FROM AUTHOR]

The sporadic outbreaks of human mpox diseases in the nearly twenty years have seriously influenced the public health and economic. Though the reservoirs of mpox virus (MPXV) are mainly rodents, it could spill over to humans by direct contact and cause self-limiting infection with the symptom of lymphadenopathy and rash on the skin. Since the first case reported outside Africa in the USA at the beginning of this century in America, MPXV has been gradually prevalent globally and become an increasing public threat. With the advancing technology of viral detection and gene sequencing, many novel poxviruses were detected which enriched the variety of Poxviridae family. In this review, we provide a comprehensive overview on the latest classification, host spectrum, genome feature, pathogenicity and the evolution of MPXV and other poxviruses. This information will promote our understanding of the phylogenetic relationship and infectious transmission of pathogenic poxviruses and contribute to future viral researches and disease control. [ABSTRACT FROM AUTHOR]

The aim of personalized cancer vaccines is to elicit potent and tumor-specific immune responses against neoantigens specific to each patient and to establish durable immunity, while minimizing the adverse events. Over recent years, there has been a renewed interest in personalized cancer vaccines, primarily due to the advancement of innovative technologies for the identification of neoantigens and novel vaccine delivery platforms. Here, we review the emerging field of personalized cancer vaccination, with a focus on the use of viral vectors as a vaccine platform. The recent advancements in viral vector technology have led to the development of efficient production processes, positioning personalized viral vaccines as one of the preferred technologies. Many clinical trials have shown the feasibility, safety, immunogenicity and, more recently, preliminary evidence of the anti-tumor activity of personalized vaccination, fostering active research in the field, including further clinical trials for different tumor types and in different clinical settings. [ABSTRACT FROM AUTHOR]

Vaccinia virus (VACV) infection induces prominent changes in host cell metabolism. Little is known about the global metabolic reprogramming that takes place in whole tissue during viral infection. Here, we performed a longitudinal metabolomics study in VACV-infected mouse skin to investigate metabolic changes in the tissue during infection. We assessed metabolites in homogenized skin of the ear pinnae over time in the presence or absence of antigen-specific T cells using untargeted mass spectrometry. VACV infection induced several significant metabolic changes in the tissue, including in the levels of nucleic acid metabolites (reflecting the impact of viral replication on the skin metabolome). Furthermore, monocyte- and antiviral T cell-produced metabolites, such as itaconic acid and glutamine, were significantly increased following infection, highlighting the immune response's contribution to the global skin metabolome. Additional RNA-Seq of infected skin tissue recapitulated metabolic changes identified by metabolomics analysis. Overall, our study reveals the metabolic balance of viral replication and the antiviral immune response in the skin, elucidating metabolic pathways that could contribute to cutaneous poxvirus control in vivo. [ABSTRACT FROM AUTHOR]

Oncolytic viruses (OVs) have emerged as one of the most promising cancer immunotherapy agents that selectively target and kill cancer cells while sparing normal cells. OVs are from diverse families of viruses and can possess either a DNA or an RNA genome. These viruses also have either a natural or engineered tropism for cancer cells. Oncolytic DNA viruses have the additional advantage of a stable genome and multiple-transgene insertion capability without compromising infection or replication. Herpes simplex virus 1 (HSV-1), a member of the oncolytic DNA viruses, has been approved for the treatment of cancers. This success with HSV-1 was achievable by introducing multiple genetic modifications within the virus to enhance cancer selectivity and reduce the toxicity to healthy cells. Here, we review the natural characteristics of and genetically engineered changes in selected DNA viruses that enhance the tumor tropism of these oncolytic viruses. [ABSTRACT FROM AUTHOR]

Poxviruses belong to the Poxviridae family, a group of pathogens known for their high infectivity in humans, posing significant health threats. One of the most well‐known representatives of poxvirus infections is smallpox, which has been successfully eradicated. However, in recent years, there has been a resurgence in cases of mpox, another member of the Poxviridae family, raising concerns about the potential for a global pandemic or a worldwide health crisis. While the typical clinical presentation of mpox and other poxvirus infections often involves cutaneous lesions, there have been reports of various atypical and non‐classic clinical manifestations. Dermoscopy has emerged as a crucial diagnostic tool, aiding dermatologists in clinical practice to make informed decisions. In this summary, we provide an overview of the clinical and dermoscopic features of representative cutaneous lesions associated with human poxvirus infections, including mpox, orf, milker's nodule, and molluscum contagiosum. [ABSTRACT FROM AUTHOR]

Serine protease inhibitors, SERPINS, are a highly conserved family of proteins that regulate serine proteases in the central coagulation and immune pathways, representing 2–10% of circulating proteins in the blood. Serine proteases form cascades of sequentially activated enzymes that direct thrombosis (clot formation) and thrombolysis (clot dissolution), complement activation in immune responses and also programmed cell death (apoptosis). Virus-derived serpins have co-evolved with mammalian proteases and serpins, developing into highly effective inhibitors of mammalian proteolytic pathways. Through interacting with extracellular and intracellular serine and cysteine proteases, viral serpins provide a new class of highly active virus-derived coagulation-, immune-, and apoptosis-modulating drug candidates. Viral serpins have unique characteristics: (1) function at micrograms per kilogram doses; (2) selectivity in targeting sites of protease activation; (3) minimal side effects at active concentrations; and (4) the demonstrated capacity to be modified, or fine-tuned, for altered protease targeting. To date, the virus-derived serpin class of biologics has proven effective in a wide range of animal models and in one clinical trial in patients with unstable coronary disease. Here, we outline the known viral serpins and review prior studies with viral serpins, considering their potential for application as new sources for immune-, coagulation-, and apoptosis-modulating therapeutics. [ABSTRACT FROM AUTHOR]

Zoonotic poxviruses such as mpox virus (MPXV) continue to threaten public health safety since the eradication of smallpox. Vaccinia virus (VACV), the prototypic poxvirus used as the vaccine strain for smallpox eradication, is the best-characterized member of the poxvirus family. VACV encodes a serine protease inhibitor 1 (SPI-1) conserved in all orthopoxviruses, which has been recognized as a host range factor for modified VACV Ankara (MVA), an approved smallpox vaccine and a promising vaccine vector. FAM111A (family with sequence similarity 111 member A), a nuclear protein that regulates host DNA replication, was shown to restrict the replication of a VACV SPI-1 deletion mutant (VACV-ΔSPI-1) in human cells. Nevertheless, the detailed antiviral mechanisms of FAM111A were unresolved. Here, we show that FAM111A is a potent restriction factor for VACV-ΔSPI-1 and MVA. Deletion of FAM111A rescued the replication of MVA and VACV-ΔSPI-1 and overexpression of FAM111A significantly reduced viral DNA replication and virus titers but did not affect viral early gene expression. The antiviral effect of FAM111A necessitated its trypsin-like protease domain and DNA-binding domain but not the PCNA-interacting motif. We further identified that FAM111A translocated into the cytoplasm upon VACV infection by degrading the nuclear pore complex via its protease activity, interacted with VACV DNA-binding protein I3, and promoted I3 degradation through autophagy. Moreover, SPI-1 from VACV, MPXV, or lumpy skin disease virus was able to antagonize FAM111A by prohibiting its nuclear export. Our findings reveal the detailed mechanism by which FAM111A inhibits VACV and provide explanations for the immune evasive function of VACV SPI-1. [ABSTRACT FROM AUTHOR]

Smallpox was eradicated in less than 200 years after Edward Jenner's practice of cowpox variolation in 1796. The forty-three years of us living free of smallpox, beginning in 1979, never truly separated us from poxviruses. The recent outbreak of monkeypox in May 2022 might well warn us of the necessity of keeping up both the scientific research and public awareness of poxviruses. One of them in particular, the vaccinia virus (VACV), has been extensively studied as a vector given its broad host range, extraordinary thermal stability, and exceptional immunogenicity. Unceasing fundamental biological research on VACV provides us with a better understanding of its genetic elements, involvement in cellular signaling pathways, and modulation of host immune responses. This enables the rational design of safer and more efficacious next-generation vectors. To address the new technological advancement within the past decade in VACV research, this review covers the studies of viral immunomodulatory genes, modifications in commonly used vectors, novel mechanisms for rapid generation and purification of recombinant virus, and several other innovative approaches to studying its biology. [ABSTRACT FROM AUTHOR]

In African countries where mpox (monkeypox) is endemic, infection is caused by two genetically related clades—Clade I (formerly Congo Basin), and Clade IIa (formerly West Africa), both of which are potentially life-threatening infections. Prior to the 2022–2023 global outbreak, mpox infections among pregnant women caused by Clade I were reported to have a 75% perinatal case fatality rate in the Democratic Republic of Congo, including the only documented case of placental infection and stillbirth from the Congenital Mpox Syndrome, and the Clade IIa mpox infection was associated with stillbirths in Nigeria. The 2022–2023 global mpox outbreak, caused by a genetically distinct strain, Clade IIb, has focused attention on the effects of mpox on pregnant women and fetal outcomes. There have been at least 58 cases of mpox infection occurring in pregnant women during the 2022–2023 outbreak. No confirmed cases of adverse perinatal outcome, including stillbirth, have been reported. The absence of perinatal morbidity and mortality from Clade IIb corresponds to the overall case fatality rate among non-pregnant women of <0.1%, as this clade has been demonstrated to produce a less-severe disease than the mpox Clade I or IIa variants. Thus, there are apparently important differences between mpox clades affecting pregnant women and perinatal outcomes. [ABSTRACT FROM AUTHOR]

The SARS-CoV-2 pandemic demonstrated the need for potent and broad-spectrum vaccines. This study reports the development and testing of a lumpy skin disease virus (LSDV)-vectored vaccine against SARS-CoV-2, utilizing stabilized spike and conserved nucleocapsid proteins as antigens to develop robust immunogenicity. Construction of the vaccine (LSDV-SARS2-S,N) was confirmed by polymerase chain reaction (PCR) amplification and sequencing. In vitro characterization confirmed that cells infected with LSDV-SARS2-S,N expressed SARS-CoV-2 spike and nucleocapsid protein. In BALB/c mice, the vaccine elicited high magnitude IFN-γ ELISpot responses (spike: 2808 SFU/106 splenocytes) and neutralizing antibodies (ID50 = 6552). Testing in hamsters, which emulate human COVID-19 disease progression, showed the development of high titers of neutralizing antibodies against the Wuhan and Delta SARS-CoV-2 variants (Wuhan ID50 = 2905; Delta ID50 = 4648). Additionally, hamsters vaccinated with LSDV-SARS2-S,N displayed significantly less weight loss, lung damage, and reduced viral RNA copies following SARS-CoV-2 infection with the Delta variant as compared to controls, demonstrating protection against disease. These data demonstrate that LSDV-vectored vaccines display promise as an effective SARS-CoV-2 vaccine and as a potential vaccine platform for communicable diseases in humans and animals. Further efficacy testing and immune response analysis, particularly in non-human primates, are warranted. [ABSTRACT FROM AUTHOR]

Bioindicators of wildlife health are useful tools for studying the viability of various organisms and populations, and can include a range of phenotypic variables, such as behavior, body size, and physiological parameters, such as circulating hormones and nutrients. Few studies have investigated the utility of total plasma protein as a predictor of environmental or nutritional variation among birds, as well as variation across different habitats and life-history stages. Here, we examined relationships between plasma protein and season, urbanization, sex, body condition, molt status, and disease state in House Finches (Haemorhous mexicanus). We sampled blood from House Finches across three seasons (winter, summer, and fall 2021) and measured plasma protein levels using a Bradford assay. We also collected data including condition, sex, and poxvirus infection state at capture, as well as fecal samples to assess gut parasitism (coccidiosis). During the fall season, we also estimated molt status, as number of actively growing feathers. We found a significant relationship between circulating protein levels and capture site, as well as novel links to molt state and pox presence, with urban birds, those infected with pox, and those in more intense molt having higher protein levels. Our results support the hypotheses that plasma protein concentration can be indicative of a bird's body molt and degree of habitat urbanization, although future work is needed to determine why protein levels were higher in virus-infected birds. [ABSTRACT FROM AUTHOR]

The widespread outbreak of the monkeypox virus (MPXV) recognized in 2022 poses new challenges for public healthcare systems worldwide. With more than 86,000 people infected, there is concern that MPXV may become endemic outside of its original geographical area leading to repeated human spillover infections or continue to be spread person-to-person. Fortunately, classical public health measures (e.g., isolation, contact tracing and quarantine) and vaccination have blunted the spread of the virus, but cases are continuing to be reported in 28 countries in March 2023. We describe here the vaccines and drugs available for the prevention and treatment of MPXV infections. However, although their efficacy against monkeypox (mpox) has been established in animal models, little is known about their efficacy in the current outbreak setting. The continuing opportunity for transmission raises concerns about the potential for evolution of the virus and for expansion beyond the current risk groups. The priorities for action are clear: 1) more data on the efficacy of vaccines and drugs in infected humans must be gathered; 2) global collaborations are necessary to ensure that government authorities work with the private sector in developed and low and middle income countries (LMICs) to provide the availability of treatments and vaccines, especially in historically endemic/enzootic areas; 3) diagnostic and surveillance capacity must be increased to identify areas and populations where the virus is present and may seed resurgence; 4) those at high risk of severe outcomes (e.g., immunocompromised, untreated HIV, pregnant women, and inflammatory skin conditions) must be informed of the risk of infection and be protected from community transmission of MPXV; 5) engagement with the hardest hit communities in a non-stigmatizing way is needed to increase the understanding and acceptance of public health measures; and 6) repositories of monkeypox clinical samples, including blood, fluids, tissues and lesion material must be established for researchers. This MPXV outbreak is a warning that pandemic preparedness plans need additional coordination and resources. We must prepare for continuing transmission, resurgence, and repeated spillovers of MPXV. [ABSTRACT FROM AUTHOR]

Lumpy Skin disease (LSD) is an economically important disease in cattle caused by the LSD virus (LSDV) of the genus Capripoxvirus, while pseudocowpox (PCP) is a widely distributed zoonotic cattle disease caused by the PCP virus (PCPV) of the genus Parapoxvirus. Though both viral pox infections are reportedly present in Nigeria, similarities in their clinical presentation and limited access to laboratories often lead to misdiagnosis in the field. This study investigated suspected LSD outbreaks in organized and transhumance cattle herds in Nigeria in 2020. A total of 42 scab/skin biopsy samples were collected from 16 outbreaks of suspected LSD in five northern States of Nigeria. The samples were analyzed using a high-resolution multiplex melting (HRM) assay to differentiate poxviruses belonging to Orthopoxvirus, Capripoxvirus, and Parapoxvirus genera. LSDV was characterized using four gene segments, namely the RNA polymerase 30 kDa subunit (RPO30), G-protein-coupled receptor (GPCR), the extracellular enveloped virus (EEV) glycoprotein and CaPV homolog of the variola virus B22R. Likewise, the partial B2L gene of PCPV was also analyzed. Nineteen samples (45.2%) were positive according to the HRM assay for LSDV, and five (11.9%) were co-infected with LSDV and PCPV. The multiple sequence alignments of the GPCR, EEV, and B22R showed 100% similarity among the Nigerian LSDV samples, unlike the RPO30 phylogeny, which showed two clusters. Some of the Nigerian LSDVs clustered within LSDV SG II were with commonly circulating LSDV field isolates in Africa, the Middle East, and Europe, while the remaining Nigerian LSDVs produced a unique sub-group. The B2L sequences of Nigerian PCPVs were 100% identical and clustered within the PCPV group containing cattle/Reindeer isolates, close to PCPVs from Zambia and Botswana. The results show the diversity of Nigerian LSDV strains. This paper also reports the first documented co-infection of LSDV and PCPV in Nigeria. [ABSTRACT FROM AUTHOR]

The monkeypox epidemic has attracted global attention to poxviruses. The cytoplasmic replication of poxviruses requires extensive protein synthesis, challenging the capacity of the endoplasmic reticulum (ER). However, the role of the ER in the life cycle of poxviruses is unclear. In this study, we demonstrate that infection with the lumpy skin disease virus (LSDV), a member of the poxvirus family, causes ER stress in vivo and in vitro, further facilitating the activation of the unfolded protein response (UPR). Although UPR activation aids in the restoration of the cellular environment, its significance in the LSDV life cycle remains unclear. Furthermore, the significance of ER imbalance for viral replication is also unknown. We show that LSDV replication is hampered by an unbalanced ER environment. In addition, we verify that the LSDV replication depends on the activation of PERK‐eIF2α and IRE1‐XBP1 signaling cascades rather than ATF6, implying that global translation and reduced XBP1 cleavage are deleterious to LSDV replication. Taken together, these findings indicate that LSDV is involved in the repression of global translational signaling, ER chaperone transcription, and ATF6 cleavage from the Golgi into the nucleus, thereby maintaining cell homeostasis; moreover, PERK and IRE1 activation contribute to LSDV replication. Our findings suggest that targeting UPR elements may be applied in response to infection from LSDV or even other poxviruses, such as monkeypox. [ABSTRACT FROM AUTHOR]

Skin histology of papules and pustules from 5 men having sex with men with mpox infection showed viral intracytoplasmic cytopathic changes, interface dermatitis, marked inflammatory dermic infiltrate including superficial neutrophils and perivascular and periadnexal deep lymphocytes. Histologic description of mpox lesions improves our understanding about clinical presentations and may have some therapeutic implications. [ABSTRACT FROM AUTHOR]

The majority of emerging viral infectious diseases in humans originate from wildlife reservoirs, such as rodents and bats. We investigated a possible reservoir, namely wild gerbils and mice trapped in a desert reserve within the emirate of Dubai, United Arab Emirates (UAE). In total, 52 gerbils and 1 jird (Gerbillinae), 10 house mice (Mus musculus), and 1 Arabian spiny mouse (Acomys dimidiatus) were sampled. Oro-pharyngeal swabs, fecal samples, attached ticks, and organ samples (where available) were screened by (RT-q)PCR for the following viruses: Middle East respiratory syndrome-related coronavirus, Crimean-Congo hemorrhagic fever orthonairovirus, Alkhumra hemorrhagic fever virus, hantaviruses, Lymphocytic choriomeningitis mammarenavirus, Rustrela virus, poxviruses, flaviviruses, and herpesviruses. All of the samples were negative for all investigated viruses, except for herpesviruses: 19 gerbils (35.8%) and seven house mice (70.0%) were positive. The resulting sequences were only partly identical to sequences in GenBank. Phylogenetic analysis revealed three novel betaherpesviruses and four novel gammaherpesviruses. Interestingly, species identification of the positive gerbils resulted in eight individuals clustering in a separate clade, most closely related to Dipodillus campestris, the North African gerbil, indicating either the expansion of the geographic range of this species, or the existence of a closely related, yet undiscovered species in the UAE. In conclusion, we could not find evidence of persistence or shedding of potentially zoonotic viruses in the investigated rodent cohorts of limited sample size. [ABSTRACT FROM AUTHOR]

The WHO declares a pandemic when there is a community transmission of a disease that is occurring in at least two countries in two WHO regions. This research evaluated the current (year 2022) outbreak of monkeypox against the criteria of a pandemic and suggests necessary health interventions. Monkeypox is a zoonotic disease, causing diseases in humans similar to smallpox. Since its discovery in humans in 1970, several outbreaks have occurred with the most recent spreading widely to non-endemic areas and fulfilling the WHO criteria for phase 6 of an outbreak as high cases of infections were seen in Europe and America. Although, the pandemic from monkeypox may not be remarkable because the basic reproductive number, attack, and case fatality rates are much lower than some of the previous pandemics. However, it should not be underestimated, as spread to vulnerable groups may be detrimental. It is therefore important for the health systems of countries to develop a pandemic preparedness and response plan for monkeypox and continue to monitor the outbreak with a prompt response when needed. [ABSTRACT FROM AUTHOR]

Monkeypox is a disease transmitted through animals but can also spread from human to human. The causative agent is monkeypox virus which is a ds-DNA virus. Monkeypox virus belongs to the orthopox genus of the poxviridae family. Other members of this family are the variola virus and the vaccinia virus. This virus was first discovered in 1958. In 1970, when various types of research were going on to eradicate smallpox, the first case of smallpox in humans was reported in the Democratic Republic of Congo. Both smallpox and monkeypox share the same clinical features. Other symptoms are adenopathy and papular rashes. Monkeypox can spread through various modes of transmission. The most common mode is direct contact with contagious animals or contagious humans. Disease progression can be limited by spreading awareness, among the people about the factors responsible for transmission, clinical manifestations, and preventive methodologies. [ABSTRACT FROM AUTHOR]

CV301 comprises recombinant poxviruses, Modified Vaccinia Ankara (MVA) and Fowlpox (FPV), encoding CEA, MUC-1, and co-stimulatory Molecules (TRICOM) ICAM-1, LFA-3, and B7-1. MVA-BN-CV301 is used for priming and FPV-CV301 is used for boosting. A Phase 2, single-arm trial was designed to evaluate CV301 plus atezolizumab as first-line treatment for cisplatin-ineligible advanced urothelial carcinoma (aUC) (Cohort 1) or progressing after platinum chemotherapy (Cohort 2). MVA-CV301 was given subcutaneously (SC) on Days 1 and 22 and FPV-CV301 SC from day 43 every 21 days for 4 doses, then tapered gradually over up to 2 years. Atezolizumab 1200 mg IV was given every 21 days. The primary endpoint was objective response rate (ORR). Overall, 43 evaluable patients received therapy: 19 in Cohort 1; 24 in Cohort 2; nine experienced ≥ Grade 3 therapy-related adverse events. In Cohort 1, one had partial response (PR) (ORR 5.3%, 90% CI 0.3, 22.6). In Cohort 2, 1 complete response and 1 PR were noted (ORR 8.3%, 90% CI 1.5, 24.0). The trial was halted for futility. Patients exhibiting benefit demonstrated T-cell response to CEA and MUC-1. The trial illustrates the challenges in the development of vaccines, which should be guided by robust preclinical data. [ABSTRACT FROM AUTHOR]

Receptor-interacting protein kinase 3 (RIPK3) and mixed lineage kinase domain-like pseudokinase (MLKL) are proteins that are critical for necroptosis, a mechanism of programmed cell death that is both activated when apoptosis is inhibited and thought to be antiviral. Here, we investigated the role of RIPK3 and MLKL in controlling the Orthopoxvirus ectromelia virus (ECTV), a natural pathogen of the mouse. We found that C57BL/6 (B6) mice deficient in RIPK3 (Ripk32/2) or MLKL (Mlkl2/2) were as susceptible as wild-type (WT) B6 mice to ECTV lethality after low-dose intraperitoneal infection and were as resistant as WT B6 mice after ECTV infection through the natural footpad route. Additionally, after footpad infection, Mlkl2/2 mice, but not Ripk32/2 mice, endured lower viral titers than WT mice in the draining lymph node (dLN) at three days postinfection and in the spleen or in the liver at seven days postinfection. Despite the improved viral control, Mlkl2/2 mice did not differ from WT mice in the expression of interferons or interferon-stimulated genes or in the recruitment of natural killer (NK) cells and inflammatory monocytes (iMOs) to the dLN. Additionally, the CD8 T-cell responses in Mlkl2/2 and WT mice were similar, even though in the dLNs of Mlkl2/2 mice, professional antigen-presenting cells were more heavily infected. Finally, the histopathology in the livers of Mlkl2/2 and WT mice at 7 dpi did not differ. Thus, the mechanism of the increased virus control by Mlkl2/2 mice remains to be defined. IMPORTANCE The molecules RIPK3 and MLKL are required for necroptotic cell death, which is widely thought of as an antiviral mechanism. Here we show that C57BL/6 (B6) mice deficient in RIPK3 or MLKL are as susceptible as WT B6 mice to ECTV lethality after a low-dose intraperitoneal infection and are as resistant as WT B6 mice after ECTV infection through the natural footpad route. Mice deficient in MLKL are more efficient than WT mice at controlling virus loads in various organs. This improved viral control is not due to enhanced interferon, natural killer cell, or CD8 T-cell responses. Overall, the data indicate that deficiencies in the molecules that are critical to necroptosis do not necessarily result in worse outcomes following viral infection and may improve virus control. [ABSTRACT FROM AUTHOR]

The decline in cross-protection provided by the smallpox vaccine increases the risk of infection from other poxviruses. While drug combinations are a promising management, they remain underdeveloped for poxviruses. Prior to the development of the smallpox vaccine, China had long relied on herbal medicine to combat pox and accumulated a wealth of knowledge regarding different herb combinations and symptoms related to pox. The information was documented in the form of prescriptions. The extensive data of prescriptions offer the potential for uncovering commonalities underlying these prescriptions, thereby providing valuable insights into the development of drug combinations against pox. The 2344 prescriptions were collected from the LTM-TCM database and 12 traditional Chinese medicine books. Firstly, the relative frequency of citation was utilized to identify the most used herbs among these prescriptions. TCMSP and LTM-TCM databases were employed to gather information about active compounds and their targets. GeneCards and DisGeNET databases were utilized to determine the associated targets for smallpox, cowpox, chickenpox, and mpox. Subsequently, network pharmacology analysis was conducted to investigate potential pathway information related to the most used herbs. A comparison of active compounds from these herbs resulted in the identification of 29 high-frequency compounds. The functions of these compounds were elucidated through gene overlap analysis, docking, and literature review. Finally, we summarized pox-related symptoms and used fidelity levels to distinguish specific herbs for corresponding symptoms. Based on 2344 traditional pox-related prescriptions, we identified 19 most used herbs and 64 associated bio-functional modules for poxvirus treatment, with the most significant one being immunoregulation primarily involving CD4+ regulation. We also identified 29 leads that possess anti-inflammatory, antimicrobial, and antiviral properties. These herbs and leads hold the potential for pox treatment. Additionally, docking analysis suggested that these leads could inhibit poxvirus DNA synthesis, RNA capping machinery processes, and mature poxvirus particle formation, as well as immunosuppressors. The clinical features of mpox in 2022 were found to align well with our description of symptoms related to the pox. Through the analysis of 2344 prescriptions for pox treatment, we obtained a comprehensive library of the most used herbs and high-frequency compounds, along with their potential functional spectrum. These libraries served as raw resources for drug combination development, while the identified symptom patterns and specific herbs greatly enhanced our insight into diverse treatments for pox patients. [Display omitted] • 19 herbal medicines and 29 compounds showed high frequency in 2344 prescriptions related to pox. • The most used herbs exhibited similar multi-module cooperation patterns in the treatment of pox. • The 29 molecules showed different potential for pox, such as antivirus, antibacterial, and anti-inflammation. • The extra 19 specific herbal medicines were found for different pox symptoms. [ABSTRACT FROM AUTHOR]

Low molecular weight proteins, known as chemokines, facilitate the migration and localization of immune cells to the site of infection and injury. One of the first chemokines identified, CXCL8 functions as a key neutrophil activator, recruiting neutrophils to sites of inflammation. Several viral infections, including zoonotic coronaviruses and poxviruses, have been reported to induce the expression of CXCL8. Dromedary camels are known to harbor several potentially zoonotic pathogens, but critical immune molecules such as chemokines remain unidentified. We report here the identification of CXCL8 from the dromedary camel - the first chemokine identified from camelids. The complete dromedary CXCL8 cDNA sequence as well as the corresponding gene sequence from dromedary and two New World camelids - alpaca and llama were cloned. CXCL8 mRNA expression was relatively higher in PBMC, spleen, lung, intestine, and liver. Poly(I:C) and lipopolysaccharide stimulated CXCL8 expression in vitro , while interferon treatment inhibited it. In vitro infection with potentially zoonotic camelpox virus induced the expression of CXCL8 in camel kidney cells. Toxicological studies on camelids have been limited, and no biomarkers have been identified. Hence, we also evaluated CXCL8 mRNA expression as a potential biomarker to assess heavy metal toxicity in camel kidney cells in vitro. CXCL8 expression was increased after in vitro exposure to heavy metal compounds of cobalt and cadmium, suggesting potential utility as a biomarker for renal toxicity in camels. The results of our study demonstrate that camel CXCL8 plays a significant role in immunomodulatory and induced toxicity responses in dromedary camels. • Dromedary CXCL8 - the first chemokine identified from camelids. • Camelpox virus infection induces the expression of CXCL8 in vitro. • Poly(I:C) and LPS stimulates CXCL8 expression in vitro , while IFN inhibits it. • CXCL8 expression induced in camel kidney cells exposed to heavy metals in vitro. • CXCL8 show potential utility as biomarker for in vitro toxicity in camels. [ABSTRACT FROM AUTHOR]

• ANK repeat proteins form an L-shaped helix-loop-helix structure consisting of a 33-aa motif. • These proteins interact with other proteins and regulate cell signaling, apoptosis, and inflammatory reactions. • These proteins are rare in viruses with the exception of poxviruses, representing a large family. • In poxviruses, these proteins feature ankyrin repeats in the N-terminal and F-box homolog in the C-terminal. • These proteins enhance viral virulence and hence act as targets for viral anti-therapeutic development. Ankyrin repeat is a 33-amino acid motif commonly observed in eukaryotes and, to a lesser extent, in prokaryotes and archaea and rarely in viruses. This motif plays a crucial role in regulating various cellular processes like the cell cycle, transcription, cell signaling, and inflammatory responses through interactions between proteins. Poxviruses exhibit a distinctive feature of containing multiple ankyrin repeat proteins within their genomes. All the genera of poxviruses possess these proteins except molluscipox virus, crocodylidpox virus, and red squirrel poxvirus. An intriguing characteristic has generated notable interest in studying the functions of these proteins within poxvirus biology. Within poxviruses, ankyrin repeat proteins exhibit a distinct configuration, featuring ankyrin repeats in the N-terminal region and a cellular F-box homolog in the C-terminal region, which enables interactions with the cellular Skp, Cullin, F-box containing ubiquitin ligase complex. Through the examination of experimental evidences and discussions from current literature, this review elucidates the organization and role of ankyrin repeat proteins in poxviruses. Various research studies have highlighted the significant importance of these proteins in poxviral pathogenesis and, acting as factors that enhance virulence. Consequently, they represent viable targets for developing genetically altered viruses with decreased virulence, thus displaying potential as candidates for vaccines and antiviral therapeutic development contributing to safer and more effective strategies against poxviral infections. [ABSTRACT FROM AUTHOR]

The Wyeth strain of vaccinia virus (VACV) produced by Wyeth Pharmaceuticals was supposedly used to manufacture the old freeze-dried American smallpox vaccine, Dryvax, until its discontinuation in 2008. Although the genomic sequences of numerous Dryvax clones have been reported, data on VACV-Wyeth genomes are still lacking. Genomic analysis of old VACV strains is relevant to understand the evolutionary relationships of smallpox vaccines, particularly with the recent resumption of smallpox vaccination in certain population groups as an attempt to control the worldwide monkeypox outbreak. Here we analyzed the complete genome sequences of three VACV-Wyeth clonal isolates obtained from a single seed vial donated to the Brazilian eradication program in the 1970s. Wyeth clones show >99.3% similarity to each other and >95.3% similarity with Dryvax clones, mapping together in clade I of the vaccinia group. Although the patterns of SNPs and INDELs comparing Dryvax and Wyeth clones are overall uniform, important differences were detected particularly at the ends of the genome. In addition, we detected recombinant events of clone Wyeth A111 and the Dryvax clone Acam2000, suggesting that other regions of the genomes may have similar patchy patterns of recombination. A small-scale serological survey using VACV-Wyeth as antigen in ELISA assays revealed that 63 of the 65 individuals born before the end of smallpox vaccination in Brazil still have anti-VACV IgG antibodies, demonstrating the usefulness of the VACV-Wyeth strain in future extended serological studies of the Brazilian population. [ABSTRACT FROM AUTHOR]

Monkeypox has been a neglected, zoonotic tropical disease for over 50 years. Since the 2022 global outbreak, hundreds of human clinical samples have been subjected to next-generation sequencing (NGS) worldwide with raw data deposited in public repositories. However, sequence analysis for in-depth investigation of viral evolution remains hindered by the lack of a curated, whole genome Monkeypox virus (MPXV) database (DB) and efficient bioinformatics pipelines. To address this, we developed a customized MPXV DB for integration with "ready-to-use" workflows in the CLC Microbial Genomics Module for whole genomic and metagenomic analysis. After database construction (218 MPXV genomes), whole genome alignment, pairwise comparison, and evolutionary analysis of all genomes were analyzed to autogenerate tabular outputs and visual displays (collective runtime: 16 min). The clinical utility of the MPXV DB was demonstrated by using a Chimpanzee fecal, hybrid-capture NGS dataset (publicly available) for metagenomic, phylogenomic, and viral/host integration analysis. The clinically relevant MPXV DB embedded in CLC workflows proved to be a rapid method of sequence analysis useful for phylogenomic exploration and a wide range of applications in translational science. [ABSTRACT FROM AUTHOR]

The last two decades have seen the emergence of three highly pathogenic coronaviruses with zoonotic origins, which prompted immediate attention to the underlying cause and prevention of future outbreaks. Intensification of camel husbandry in the Middle East has resulted in increased human-camel interactions, which has led to the spread of potentially zoonotic viruses with human spillover risks like MERS-coronavirus, camelpox virus, etc. Type-I interferons function as the first line of defense against invading viruses and are pivotal for limiting viral replication and immune-mediated pathologies. Seven novel dromedary camel interferon delta genes were identified and cloned. Functional characterization of this novel class of IFNs from the mammalian suborder tylopoda is reported for the first time. The camel interferon-delta proteins resemble the reported mammalian counterparts in sequence similarity, conservation of cysteines, and phylogenetic proximity. Prokaryotically expressed recombinant camel interferon-δ1 induced IFN-stimulated gene expression and also exerted antiviral action against camelpox virus, an endemic zoonotic virus. The pre-treatment of camel kidney cells with recombinant camel IFN-δ1 increased cell survival and reduced camelpox virus in a dose-dependent manner. The identification of novel IFNs from species with zoonotic spillover risk such as camels, and evaluating their antiviral effects in-vitro will play a key role in improving immunotherapies against viruses and expanding the arsenal to combat emerging zoonotic pathogens. • Seven functional IFN-δ genes and a pseudogene isolated from the dromedary camel. • First functional characterization of IFN-δs in mammals other than pigs, horses, and sheep. • Recombinant camel IFN-δ1 protein produced and purified from E.coli inclusion bodies by on-column refolding. • Recombinant IFN-δ1 induced IFN-responsive genes in camel kidney cells. • Camelpox virus was sensitive to recombinant dromedary IFN-δ1 in-vitro. [ABSTRACT FROM AUTHOR]

Since April 2022, cases of simian orthopoxvirosis (commonly known as monkeypox) have been reported in more than hundred non-endemic countries. The causative agent, the Monkeypox virus (MPXV), is a virus of the family Poxviridae belonging to the genus Orthopoxvirus (OPXV). The sudden and unusual emergence of this virus mainly in Europe and in the United States has highlighted a previously neglected infectious disease. This virus has been endemic in Africa for at least several decades, since its discovery in 1958 in captive monkeys. MPXV, because of its proximity to the smallpox virus, is part of the list of Microorganisms and Toxins (MOT), which includes all human pathogens considered to be potentially misused for malicious purposes (biological weapons proliferation, bioterrorism) or susceptible to provoke laboratory accidents. As such, its use is subjected to strict regulations in level-3 biosafety laboratories, which de facto limits the possibilities of its study in France. The objective of this article is to review the current knowledge about OPXV in general, and then to focus on the virus responsible for the 2022 MPXV outbreak. [ABSTRACT FROM AUTHOR]

The article discusses the emergence of the Alaskapox virus (AKPV) in the Arctic region. AKPV is a type of Orthopoxvirus and is related to other poxviruses that affect human health, such as smallpox and monkeypox. So far, there have been seven reported cases of AKPV infection, with symptoms including skin lesions, fever, malaise, and lymphadenopathy. Most cases have been mild and resolved within weeks to months. One fatal case was reported in an elderly man with a history of cancer and immunosuppression. The article suggests that contact with animals may play a role in the transmission of AKPV. Dermatologists in Alaska should consider AKPV infection in patients with pox-like skin lesions and take appropriate precautions. [Extracted from the article]