Conserved Fever Pathways across Vertebrates: A Herpesvirus Expressed Decoy TNF-alpha Receptor Delays Behavioral Fever in Fish.
; ; et al
in Cell Host & Microbe (2017), 21(2), 244-253
Both endotherms and ectotherms (e.g., fish) increase their body temperature to limit pathogen infection. Ectotherms do so by moving to warmer places, hence the term "behavioral fever." We studied the ... [more ▼]
Both endotherms and ectotherms (e.g., fish) increase their body temperature to limit pathogen infection. Ectotherms do so by moving to warmer places, hence the term "behavioral fever." We studied the manifestation of behavioral fever in the common carp infected by cyprinid herpesvirus 3, a native carp pathogen. Carp maintained at 24 degrees C died from the infection, whereas those housed in multi-chamber tanks encompassing a 24 degrees C-32 degrees C gradient migrated transiently to the warmest compartment and survived as a consequence. Behavioral fever manifested only at advanced stages of infection. Consistent with this, expression of CyHV-3 ORF12, encoding a soluble decoy receptor for TNF-alpha, delayed the manifestation of behavioral fever and promoted CyHV-3 replication in the context of a temperature gradient. Injection of anti-TNF-alpha neutralizing antibodies suppressed behavioral fever, and decreased fish survival in response to infection. This study provides a unique example of how viruses have evolved to alter host behavior to increase fitness. [less ▲]Detailed reference viewed: 18 (3 ULg)
Behavioral fever in ectothermic vertebrates.
; ; Vanderplasschen, Alain
in Developmental & Comparative Immunology (2017), 66
Fever is an evolutionary conserved defense mechanism which is present in both endothermic and ectothermic vertebrates. Ectotherms in response to infection can increase their body temperature by moving to ... [more ▼]
Fever is an evolutionary conserved defense mechanism which is present in both endothermic and ectothermic vertebrates. Ectotherms in response to infection can increase their body temperature by moving to warmer places. This process is known as behavioral fever. In this review, we summarize the current knowledge on the mechanisms of induction of fever in mammals. We further discuss the evolutionary conserved mechanisms existing between fever of mammals and behavioral fever of ectothermic vertebrates. Finally, the experimental evidences supporting an adaptive value of behavioral fever expressed by ectothermic vertebrates are summarized. [less ▲]Detailed reference viewed: 24 (2 ULg)
Viral glycoprotein gp150 promotes sexual transmission of Murid Herpesvirus-4
Zeippen, Caroline ; Javaux, Justine ; Xiao, Xue et al
Poster (2016, November 28)
Gammaherpesviruses are important pathogens in human and veterinary medicine. During co-evolution with their hosts, they developed many strategies allowing them to shed infectious particles in presence of ... [more ▼]
Gammaherpesviruses are important pathogens in human and veterinary medicine. During co-evolution with their hosts, they developed many strategies allowing them to shed infectious particles in presence of immune response. Understanding these strategies is likely to be important to control infection. Interestingly, we recently observed that Murid herpesvirus 4 (MuHV-4), a gammaherpesvirus infecting laboratory mice, could be sexually transmitted between mice. This model offers therefore the opportunity to understand the mechanisms underlying natural transmission. Some of these mechanisms could rely on the glycoprotein 150 (gp150), which could limit virus neutralization and promote the release of infectious particles from cells. In this study, we tested therefore the importance of gp150 in the context of MuHV-4 sexual transmission. Briefly, female mice were infected with WT or gp150- strains expressing luciferase. They were imaged with an in vivo imaging system to follow infection. When lytic replication was observed in the genital tract, infected females were mated with naïve males to compare the capacity of transmission of the two strains. Our results show that, while the gp150- strain has no deficit in reaching and replicating in the female genital tract, it displays a major deficit of sexual transmission in comparison with WT virions. Interestingly, this deficit appears to reflect a deficit of virions release from vaginal epithelial cells. Altogether, our results show that, while gp150 is not required for efficient dissemination and maintenance of MuHV-4 within its host, it is essential for efficient transmission, by promoting the releasing of infectious particles from the mucosal cells. [less ▲]Detailed reference viewed: 27 (3 ULg)
Replacement of Glycoprotein B in Alcelaphine Herpesvirus 1 by Its Ovine Herpesvirus 2 Homolog : Implications in Vaccine Development for Sheep-Associated Malignant Catarrhal Fever.
; ; Dewals, Benjamin G et al
in mSphere (2016), 1(4), 00108-16
Vaccine development is a top priority in malignant catarrhal fever (MCF) research. In the case of sheep-associated MCF (SA-MCF) caused by ovine herpesvirus 2 (OvHV-2), progress toward this objective has ... [more ▼]
Vaccine development is a top priority in malignant catarrhal fever (MCF) research. In the case of sheep-associated MCF (SA-MCF) caused by ovine herpesvirus 2 (OvHV-2), progress toward this objective has been hindered by the absence of methods to attenuate or modify the virus, since it cannot be propagated in vitro. As an alternative for vaccine development, in this study, we tested the hypothesis that one of the SA-MCF vaccine candidate targets, OvHV-2 glycoprotein B (gB), could be expressed by a nonpathogenic alcelaphine herpesvirus 1 (AlHV-1) and then evaluated the potential of the AlHV-1/OvHV-2 chimera to be used as a vaccine and a diagnostic tool. The construction and characterization of an AlHV-1/OvHV-2 chimeric virus that is nonpathogenic and expresses an OvHV-2 vaccine target are significant steps toward the development of an SA-MCF vaccine and also provide a valuable means to study OvHV-2 biology. [less ▲]Detailed reference viewed: 25 (3 ULg)
Genomic duplication and translocation of reactivation transactivator and bZIP-homolog genes is a conserved event in alcelaphine herpesvirus 1.
Myster, Françoise ; ; et al
in Scientific Reports (2016), 6
Alcelaphine herpesvirus 1 (AlHV-1) is a gammaherpesvirus carried asymptomatically by wildebeest. Upon cross-species transmission, AlHV-1 induces malignant catarrhal fever (MCF), a fatal ... [more ▼]
Alcelaphine herpesvirus 1 (AlHV-1) is a gammaherpesvirus carried asymptomatically by wildebeest. Upon cross-species transmission, AlHV-1 induces malignant catarrhal fever (MCF), a fatal lymphoproliferative disease of ruminants, including cattle. The strain C500 has been cloned as an infectious, pathogenic bacterial artificial chromosome (BAC) that is used to study MCF. Although AlHV-1 infection can be established in cell culture, multiple passages in vitro cause a loss of virulence associated with rearrangements of the viral genome. Here, sequencing of the BAC clone showed that the long unique region (LUR) of the genome is nearly identical to that of the previously sequenced strain from which the BAC was derived, and identified the duplication and translocation of a region from within LUR, containing the entire coding sequences of ORF50-encoding reactivation transactivator Rta and A6-encoding bZIP protein genes. The duplicated region was further located to a position within the terminal repeat (TR) and its deletion resulted in lower ORF50 expression levels and reduced viral fitness. Finally, the presence of a similar but not identical duplication and translocation containing both genes was found in AlHV-1 strain WC11. These results indicate that selection pressure for enhanced viral fitness may drive the duplication of ORF50 and A6 in AlHV-1. [less ▲]Detailed reference viewed: 14 (2 ULg)
Long term-cultured and cryopreserved primordial germ cells from various chicken breeds retain high proliferative potential and gonadal colonisation competency
Tonus, Céline ; ; Ectors, Fabien et al
in Reproduction, Fertility and Development (2016), 28(5), 628-639Detailed reference viewed: 151 (75 ULg)
Deletion of Murid Herpesvirus 4 ORF63 Affects the Trafficking of Incoming Capsids toward the Nucleus.
Latif, Muhammad Bilal ; Machiels, Bénédicte ; Xiao, Xue et al
in Journal of virology (2016), 90(5), 2455-72
Gammaherpesviruses are important human and animal pathogens. Despite the fact that they display the classical architecture of herpesviruses, the function of most of their structural proteins is still ... [more ▼]
Gammaherpesviruses are important human and animal pathogens. Despite the fact that they display the classical architecture of herpesviruses, the function of most of their structural proteins is still poorly defined. This is especially true for tegument proteins. Interestingly, a potential role in immune evasion has recently been proposed for the tegument protein encoded by Kaposi's sarcoma-associated herpesvirus open reading frame 63 (ORF63). To gain insight about the roles of ORF63 in the life cycle of a gammaherpesvirus, we generated null mutations in the ORF63 gene of murid herpesvirus 4 (MuHV-4). We showed that disruption of ORF63 was associated with a severe MuHV-4 growth deficit both in vitro and in vivo. The latter deficit was mainly associated with a defect of replication in the lung but did not affect the establishment of latency in the spleen. From a functional point of view, inhibition of caspase-1 or the inflammasome did not restore the growth of the ORF63-deficient mutant, suggesting that the observed deficit was not associated with the immune evasion mechanism identified previously. Moreover, this growth deficit was also not associated with a defect in virion egress from the infected cells. In contrast, it appeared that MuHV-4 ORF63-deficient mutants failed to address most of their capsids to the nucleus during entry into the host cell, suggesting that ORF63 plays a role in capsid movement. In the future, ORF63 could therefore be considered a target to block gammaherpesvirus infection at a very early stage of the infection. IMPORTANCE: The important diseases caused by gammaherpesviruses in human and animal populations justify a better understanding of their life cycle. In particular, the role of most of their tegument proteins is still largely unknown. In this study, we used murid herpesvirus 4, a gammaherpesvirus infecting mice, to decipher the role of the protein encoded by the viral ORF63 gene. We showed that the absence of this protein is associated with a severe growth deficit both in vitro and in vivo that was mainly due to impaired migration of viral capsids toward the nucleus during entry. Together, our results provide new insights about the life cycle of gammaherpesviruses and could allow the development of new antiviral strategies aimed at blocking gammaherpesvirus infection at the very early stages. [less ▲]Detailed reference viewed: 27 (6 ULg)
Structural Proteomics of Herpesviruses.
; Gillet, Laurent ; Vanderplasschen, Alain et al
in Viruses (2016), 8(2),
Herpesviruses are highly prevalent viruses associated with numerous pathologies both in animal and human populations. Until now, most of the strategies used to prevent or to cure these infections have ... [more ▼]
Herpesviruses are highly prevalent viruses associated with numerous pathologies both in animal and human populations. Until now, most of the strategies used to prevent or to cure these infections have been unsuccessful because these viruses have developed numerous immune evasion mechanisms. Therefore, a better understanding of their complex lifecycle is needed. In particular, while the genome of numerous herpesviruses has been sequenced, the exact composition of virions remains unknown for most of them. Mass spectrometry has recently emerged as a central method and has permitted fundamental discoveries in virology. Here, we review mass spectrometry-based approaches that have recently allowed a better understanding of the composition of the herpesvirus virion. In particular, we describe strategies commonly used for proper sample preparation and fractionation to allow protein localization inside the particle but also to avoid contamination by nonstructural proteins. A collection of other important data regarding post-translational modifications or the relative abundance of structural proteins is also described. This review also discusses the poorly studied importance of host proteins in herpesvirus structural proteins and the necessity to develop a quantitative workflow to better understand the dynamics of the structural proteome. In the future, we hope that this collaborative effort will assist in the development of new strategies to fight these infections. [less ▲]Detailed reference viewed: 38 (6 ULg)
Bovine Herpesvirus 4 Modulates Its beta-1,6-N-Acetylglucosaminyltransferase Activity through Alternative Splicing.
Lété, Céline ; ; Machiels, Bénédicte et al
in Journal of virology (2016), 90(4), 2039-51
Carbohydrates play major roles in host-virus interactions. It is therefore not surprising that, during coevolution with their hosts, viruses have developed sophisticated mechanisms to hijack for their ... [more ▼]
Carbohydrates play major roles in host-virus interactions. It is therefore not surprising that, during coevolution with their hosts, viruses have developed sophisticated mechanisms to hijack for their profit different pathways of glycan synthesis. Thus, the Bo17 gene of Bovine herpesvirus 4 (BoHV-4) encodes a homologue of the cellular core 2 protein beta-1,6-N-acetylglucosaminyltransferase-mucin type (C2GnT-M), which is a key player for the synthesis of complex O-glycans. Surprisingly, we show in this study that, as opposed to what is observed for the cellular enzyme, two different mRNAs are encoded by the Bo17 gene of all available BoHV-4 strains. While the first one corresponds to the entire coding sequence of the Bo17 gene, the second results from the splicing of a 138-bp intron encoding critical residues of the enzyme. Antibodies generated against the Bo17 C terminus showed that the two forms of Bo17 are expressed in BoHV-4 infected cells, but enzymatic assays revealed that the spliced form is not active. In order to reveal the function of these two forms, we then generated recombinant strains expressing only the long or the short form of Bo17. Although we did not highlight replication differences between these strains, glycomic analyses and lectin neutralization assays confirmed that the splicing of the Bo17 gene gives the potential to BoHV-4 to fine-tune the global level of core 2 branching activity in the infected cell. Altogether, these results suggest the existence of new mechanisms to regulate the activity of glycosyltransferases from the Golgi apparatus. IMPORTANCE: Viruses are masters of adaptation that hijack cellular pathways to allow their growth. Glycans play a central role in many biological processes, and several studies have highlighted mechanisms by which viruses can affect glycosylation. Glycan synthesis is a nontemplate process regulated by the availability of key glycosyltransferases. Interestingly, bovine herpesvirus 4 encodes one such enzyme which is a key enzyme for the synthesis of complex O-glycans. In this study, we show that, in contrast to cellular homologues, this virus has evolved to alternatively express two proteins from this gene. While the first one is enzymatically active, the second results from the alternative splicing of the region encoding the catalytic site of the enzyme. We postulate that this regulatory mechanism could allow the virus to modulate the synthesis of some particular glycans for function at the location and/or the moment of infection. [less ▲]Detailed reference viewed: 33 (8 ULg)
Small RNA deep sequencing identifies viral microRNAs during malignant catarrhal fever induced by alcelaphine herpesvirus 1
Sorel, Océane ; ; Myster, Françoise et al
in Journal of General Virology (The) (2015), 96(11), 3360-3372
Alcelaphine herpesvirus 1 (AlHV-1) is a c-herpesvirus (c-HV) carried asymptomatically by wildebeest. Upon cross-species transmission, AlHV-1 induces a fatal lymphoproliferative disease named malignant ... [more ▼]
Alcelaphine herpesvirus 1 (AlHV-1) is a c-herpesvirus (c-HV) carried asymptomatically by wildebeest. Upon cross-species transmission, AlHV-1 induces a fatal lymphoproliferative disease named malignant catarrhal fever (MCF) in many ruminants, including cattle, and the rabbit model. Latency has been shown to be essential for MCF induction. However, the mechanisms causing the activation and proliferation of infected CD8+T cells are unknown. Many c-HVs express microRNAs (miRNAs). These small non-coding RNAs can regulate expression of host or viral target genes involved in various pathways and are thought to facilitate viral infection and/or mediate activation and proliferation of infected lymphocytes. The AlHV-1 genome has been predicted to encode a large number of miRNAs. However, their precise contribution in viral infection and pathogenesis in vivo remains unknown. Here, using cloning and sequencing of small RNAs we identified 36 potential miRNAs expressed in a lymphoblastoid cell line propagated from a calf infected with AlHV-1 and developing MCF. Among the sequenced candidate miRNAs, 32 were expressed on the reverse strand of the genome in two main clusters. The expression of these 32 viral miRNAs was further validated using Northern blot and quantitative reverse transcription PCR in lymphoid organs of MCF- developing calves or rabbits. To determine the concerted contribution in MCF of 28 viral miRNAs clustered in the non-protein-coding region of the AlHV-1 genome, a recombinant virus was produced. The absence of these 28 miRNAs did not affect viral growth in vitro or MCF induction in rabbits, indicating that the AlHV-1 miRNAs clustered in this non-protein-coding genomic region are dispensable for MCF induction. [less ▲]Detailed reference viewed: 34 (4 ULg)
The genome of a tortoise herpesvirus (testudinid herpesvirus 3) has a novel structure and contains a large region that is not required for replication in vitro or virulence in vivo.
Gandar, Frederic ; ; et al
in Journal of Virology (2015), 89(22), 11438-11456
Testudinid herpesvirus 3 (TeHV-3) is the causative agent of a lethal disease affecting several tortoise species. The threat that this virus poses to endangered animals is focusing efforts on ... [more ▼]
Testudinid herpesvirus 3 (TeHV-3) is the causative agent of a lethal disease affecting several tortoise species. The threat that this virus poses to endangered animals is focusing efforts on characterizing its properties, in order to enable the development of prophylactic methods. We have sequenced the genomes of the two most studied TeHV-3 strains (1976 and 4295). TeHV-3 strain 1976 has a novel genome structure and is most closely related to a turtle herpesvirus, thus supporting its classification into genus Scutavirus, subfamily Alphaherpesvirinae, family Herpesviridae. The sequence of strain 1976 also revealed viral counterparts of cellular interleukin-10 and semaphorin, which have not been described previously in members of subfamily Alphaherpesvirinae. TeHV-3 strain 4295 is a mixture of three forms (m1, m2, and M), in which, in comparison to strain 1976, the genomes exhibit large, partially overlapping deletions of 12.5 to 22.4 kb. Viral subclones representing these forms were isolated by limiting dilution assays, and each replicated in cell culture comparably to strain 1976. With the goal of testing the potential of the three forms as attenuated vaccine candidates, strain 4295 was inoculated intranasally into Hermann's tortoises (Testudo hermanni). All inoculated subjects died, and PCR analyses demonstrated the ability of the m2 and M forms to spread and invade the brain. In contrast, the m1 form was detected in none of the organs tested, suggesting its potential as the basis of an attenuated vaccine candidate. Our findings represent a major step toward characterizing TeHV-3 and developing prophylactic methods against it. [less ▲]Detailed reference viewed: 63 (14 ULg)
Long term culture, cryopreservation and genetic modification of chicken primordial germ cells
Tonus, Céline ; Garcia Gil, Francisco José ; et al
Poster (2015, October 16)
Avian primordial germ cells (PGCs) are precursor of gametes and appear during early stages of embryonic development. Under appropriate culture conditions, these cells can keep their germ cells properties ... [more ▼]
Avian primordial germ cells (PGCs) are precursor of gametes and appear during early stages of embryonic development. Under appropriate culture conditions, these cells can keep their germ cells properties in vitro and are foreseen as promising tools for developing efficient avian genetic engineering and preservation of germplasm. We propose original methods that allow long term expansion, efficient cryopreservation and genetic modification of primary cultures of undifferentiated PGCs. PGCs are collected from embryonic blood during their migratory period and grown in cell-culture insert in the presence of feeder cells (BRL). This physically separated co-culture system along with selective culture medium promoted emergence, selection and proliferation of PGCs lines. Forty percent of blood samples gave rise to lines originating from three commercial layer and two Belgian endangered breeds. PGCs lines were characterized for the expression of the stem cells and PGCs marker SSEA-1 by FACS. RT-PCR confirmed expression of germ-line specific markers (CVH, CDH, DAZL), pluripotency markers (cPouV, cSox2, cNanog), telomerase and CXCR4 receptor. All lines were male although isolated from pooled male and female blood samples. Two cryopreservation methods were developed based upon slow-freezing and aseptic vitrification. Both have shown a similar effectiveness in allowing storage without phenotype drift. Stably expressing lines were obtained by Lipofectamine® mediated transfection of a GFP plasmid. PGCs were subsequently injected in recipient embryos. Persistence of exogenous PGCs in the developing gonad of recipient embryos confirmed that PGCs retain their gonadal colonisation ability, both after long-term culture and after cryopreservation. [less ▲]Detailed reference viewed: 126 (13 ULg)
Helminth-induced inflammation controls murine γ-herpesvirus replication in the lung
Dougall, Annette ; Rolot, Marion ; Vanderplasschen, Alain et al
Conference (2015, September)Detailed reference viewed: 55 (5 ULg)
The site of administration influences both the type and the magnitude of the immune response induced by DNA vaccine electroporation
; ; et al
in Vaccine (2015), 33Detailed reference viewed: 29 (2 ULg)
Rational Development of an Attenuated Recombinant Cyprinid Herpesvirus 3 Vaccine Using Prokaryotic Mutagenesis and In Vivo Bioluminescent Imaging
Boutier, Maxime ; Ronsmans, Maygane ; et al
in PLoS Pathogens (2015), 11(2), 1004690
Cyprinid herpesvirus 3 (CyHV 3) is causing severe economic losses worldwide in common and koi carp industries, and a safe and efficacious attenuated vaccine compatible with mass vaccination is needed. We ... [more ▼]
Cyprinid herpesvirus 3 (CyHV 3) is causing severe economic losses worldwide in common and koi carp industries, and a safe and efficacious attenuated vaccine compatible with mass vaccination is needed. We produced single deleted recombinants using prokaryotic mutagenesis. When producing a recombinant lacking open reading frame 134 (ORF134), we unexpectedly obtained a clone with additional deletion of ORF56 and ORF57. This triple deleted recombinant replicated efficiently in vitro and expressed an in vivo safety/efficacy profile compatible with use as an attenuated vaccine. To determine the role of the double ORF56-57 deletion in the phenotype and to improve further the quality of the vaccine candidate, a series of deleted recombinants was produced and tested in vivo. These experiments led to the selection of a double deleted recombinant lacking ORF56 and ORF57 as a vaccine candidate. The safety and efficacy of this strain were studied using an in vivo bioluminescent imaging system (IVIS), qPCR, and histopathological examination, which demonstrated that it enters fish via skin infection similar to the wild type strain. However, compared to the parental wild type strain, the vaccine candidate replicated at lower levels and spread less efficiently to secondary sites of infection. Transmission experiments allowing water contamination with or without additional physical contact between fish demonstrated that the vaccine candidate has a reduced ability to spread from vaccinated fish to naïve sentinel cohabitants. Finally, IVIS analyses demonstrated that the vaccine candidate induces a protective mucosal immune response at the portal of entry. Thus, the present study is the first to report the rational development of a recombinant attenuated vaccine against CyHV 3 for mass vaccination of carp. We also demonstrated the relevance of the CyHV 3 carp model for studying alloherpesvirus transmission and mucosal immunity in teleost skin. [less ▲]Detailed reference viewed: 66 (12 ULg)
Cyprinid Herpesvirus 3 Il10 Inhibits Inflammatory Activities of Carp Macrophages and Promotes Proliferation of Igm+ B Cells and Memory T Cells in a Manner Similar to Carp Il10.
; ; et al
in Journal of immunology (Baltimore, Md. : 1950) (2015), 195(8), 3694-704
Cyprinid herpesvirus 3 (CyHV-3) is the causative agent of a lethal disease of carp and encodes for an Il10 homolog (ORF134). Our previous studies with a recombinant ORF134-deleted strain and the derived ... [more ▼]
Cyprinid herpesvirus 3 (CyHV-3) is the causative agent of a lethal disease of carp and encodes for an Il10 homolog (ORF134). Our previous studies with a recombinant ORF134-deleted strain and the derived revertant strain suggested that cyprinid herpesvirus 3 Il10 (CyHV-3 Il10 [cyhv3Il10]) is not essential for viral replication in vitro, or virulence in vivo. In apparent contrast, cyhv3Il10 is one of the most abundant proteins of the CyHV-3 secretome and is structurally very similar to carp Il10 and also human IL10. To date, studies addressing the biological activity of cyhv3Il10 on cells of its natural host have not been performed. To address the apparent contradiction between the presence of a structurally conserved Il10 homolog in the genome of CyHV-3 and the lack of a clear phenotype in vivo using recombinant cyhv3Il10-deleted viruses, we used an in vitro approach to investigate in detail whether cyhv3Il10 exerts any biological activity on carp cells. In this study, we provide direct evidence that cyhv3Il10 is biologically active and, similarly to carp Il10, signals via a conserved Stat3 pathway modulating immune cells of its natural host, carp. In vitro, cyhv3Il10 deactivates phagocytes with a prominent effect on macrophages, while also promoting proliferation of Igm(+) B cells and memory T cells. Collectively, this study demonstrates a clear biological activity of cyhv3Il10 on cells of its natural host and indicates that cyhv3Il10 is a true viral ortholog of carp Il10. Furthermore, to our knowledge, this is the first report on biological activities of a nonmammalian viral Il10 homolog. [less ▲]Detailed reference viewed: 17 (1 ULg)
The Structure of the Cyprinid herpesvirus 3 ORF112-Zalpha.Z-DNA Complex Reveals a Mechanism of Nucleic Acids Recognition Conserved with E3L, a Poxvirus Inhibitor of Interferon Response.
; ; Boutier, Maxime et al
in Journal of Biological Chemistry (2015), 290(52), 30713-25
In vertebrate species, the innate immune system down-regulates protein translation in response to viral infection through the action of the double-stranded RNA (dsRNA)-activated protein kinase (PKR). In ... [more ▼]
In vertebrate species, the innate immune system down-regulates protein translation in response to viral infection through the action of the double-stranded RNA (dsRNA)-activated protein kinase (PKR). In some teleost species another protein kinase, Z-DNA-dependent protein kinase (PKZ), plays a similar role but instead of dsRNA binding domains, PKZ has Zalpha domains. These domains recognize the left-handed conformer of dsDNA and dsRNA known as Z-DNA/Z-RNA. Cyprinid herpesvirus 3 infects common and koi carp, which have PKZ, and encodes the ORF112 protein that itself bears a Zalpha domain, a putative competitive inhibitor of PKZ. Here we present the crystal structure of ORF112-Zalpha in complex with an 18-bp CpG DNA repeat, at 1.5 A. We demonstrate that the bound DNA is in the left-handed conformation and identify key interactions for the specificity of ORF112. Localization of ORF112 protein in stress granules induced in Cyprinid herpesvirus 3-infected fish cells suggests a functional behavior similar to that of Zalpha domains of the interferon-regulated, nucleic acid surveillance proteins ADAR1 and DAI. [less ▲]Detailed reference viewed: 11 (0 ULg)
Cyprinid herpesvirus 3 : an archetype of fish alloherpesviruses
Boutier, Maxime ; Ronsmans, Maygane ; Rakus, Krzysztof et al
in Advances in Virus Research (2015), 93Detailed reference viewed: 66 (11 ULg)
The alpha2,3-Sialyltransferase Encoded by Myxoma Virus Is a Virulence Factor that Contributes to Immunosuppression.
; ; et al
in PloS one (2015), 10(2), 0118806
Myxoma virus (MYXV) induces a lethal disease called Myxomatosis in European rabbits. MYXV is one of the rare viruses that encodes an alpha2,3-sialyltransferase through its M138L gene. In this study, we ... [more ▼]
Myxoma virus (MYXV) induces a lethal disease called Myxomatosis in European rabbits. MYXV is one of the rare viruses that encodes an alpha2,3-sialyltransferase through its M138L gene. In this study, we showed that although the absence of the enzyme was not associated with any in vitro deficit, the M138L deficient strains are highly attenuated in vivo. Indeed, while all rabbits infected with the parental and the revertant strains died within 9 days post-infection from severe myxomatosis, all but one rabbit inoculated with the M138L deficient strains survived the infection. In primary lesions, this resistance to the infection was associated with an increased ability of innate immune cells, mostly neutrophils, to migrate to the site of virus replication at 4 days post-infection. This was followed by the development of a better specific immune response against MYXV. Indeed, at day 9 post-infection, we observed an important proliferation of lymphocytes and an intense congestion of blood vessels in lymph nodes after M138L knockouts infection. Accordingly, in these rabbits, we observed an intense mononuclear cell infiltration throughout the dermis in primary lesions and higher titers of neutralizing antibodies. Finally, this adaptive immune response provided protection to these surviving rabbits against a challenge with the MYXV WT strain. Altogether, these results show that expression of the M138L gene contributes directly or indirectly to immune evasion by MYXV. In the future, these results could help us to better understand the pathogenesis of myxomatosis but also the importance of glycans in regulation of immune responses. [less ▲]Detailed reference viewed: 42 (11 ULg)
Viral semaphorin inhibits dendritic cell phagocytosis and migration but is not essential for γ-herpesvirus-induced lymphoproliferation in malignant catarrhal fever.
Myster, Françoise ; Gonon Rodrigues Palmeira, Leonor ; Sorel, Océane et al
in Journal of Virology (2015)Detailed reference viewed: 27 (10 ULg)