RNA binding properties of the US11 protein from four primate simplexviruses.
Tohme, Sarah; Cukier, Cyprian D; Severini, Alberto
2011-11-03
The protein encoded by the Us11 gene of herpes simplex viruses is a dsRNA binding protein which inhibits protein kinase R activity, thereby preventing the interferon-induced shut down of protein synthesis following viral infection. Us11 protein is not essential for infectivity in vitro and in mice in herpes simplex virus type 1 (HSV1), however this virus has a second, and apparently more important, inhibitor of PKR activity, the γ134.5 protein. Recently sequenced simian simplexviruses SA8, HVP2 and B virus do not have an ORF corresponding to the γ134.5 protein, yet they have similar, or greater, infectivity as HSV1 and HSV2. We have expressed the US11 proteins of the simplexviruses HSV1, HSV2, HVP2 and B virus and measured their abilities to bind dsRNA, in order to investigate possible differences that could complement the absence of the γ134.5 protein. We employed a filter binding technique that allows binding of the Us11 protein under condition of excess dsRNA substrate and therefore a measurement of the true Kd value of Us11-dsRNA binding. The results show a Kd of binding in the range of 0.89 nM to 1.82 nM, with no significant difference among the four Us11 proteins.
RNA binding properties of the US11 protein from four primate simplexviruses
2011-01-01
Background The protein encoded by the Us11 gene of herpes simplex viruses is a dsRNA binding protein which inhibits protein kinase R activity, thereby preventing the interferon-induced shut down of protein synthesis following viral infection. Us11 protein is not essential for infectivity in vitro and in mice in herpes simplex virus type 1 (HSV1), however this virus has a second, and apparently more important, inhibitor of PKR activity, the γ134.5 protein. Recently sequenced simian simplexviruses SA8, HVP2 and B virus do not have an ORF corresponding to the γ134.5 protein, yet they have similar, or greater, infectivity as HSV1 and HSV2. Methods We have expressed the US11 proteins of the simplexviruses HSV1, HSV2, HVP2 and B virus and measured their abilities to bind dsRNA, in order to investigate possible differences that could complement the absence of the γ134.5 protein. We employed a filter binding technique that allows binding of the Us11 protein under condition of excess dsRNA substrate and therefore a measurement of the true Kd value of Us11-dsRNA binding. Results and Conclusions The results show a Kd of binding in the range of 0.89 nM to 1.82 nM, with no significant difference among the four Us11 proteins. PMID:22054255
Vasireddi, Mugdha; Patrusheva, Irina; Seoh, Hyuk-Kyu; Filfili, Chadi N.; Wildes, Martin J.; Oh, Jay
2017-01-01
Our overall aim is to develop epitope-based assays for accurate differential diagnosis of B virus zoonotic infections in humans. Antibodies to cross-reacting epitopes on human-simplexviruses continue to confound the interpretation of current assays where abundant antibodies exist from previous infections with HSV types 1 and 2. To find B virus-specific epitopes we cloned ten monoclonal antibodies (mAbs) from the hybridomas we produced. Our unique collection of rare human sera from symptomatic and asymptomatic patients infected with B virus was key to the evaluation and identification of the mAbs as reagents in competition ELISAs (mAb-CE). The analysis of the ten mAbs revealed that the target proteins for six mAbs was glycoprotein B of which two are reactive to simian simplexviruses and not to human simplexviruses. Two mAbs reacted specifically with B virus glycoprotein D, and two other mAbs were specific to VP13/14 and gE-gI complex respectively. The mAbs specific to VP13/14 and gE-gI are strain specific reacting with B virus isolates from rhesus and Japanese macaques and not with isolates from cynomolgus and pigtail macaques. The mAb-CE revealed that a high proportion of naturally B virus infected rhesus macaques and two symptomatic humans possess antibodies to epitopes of VP13/14 protein and on the gE-gI complex. The majority of sera from B virus infected macaques and simplexvirus-infected humans competed with the less specific mAbs. These experiments produced a novel panel of mAbs that enabled B virus strain identification and confirmation of B virus infected macaques by the mAb-CE. For human sera the mAb-CE could be used only for selected cases due to the selective B virus strain-specificity of the mAbs against VP13/14 and gE/gI. To fully accomplish our aim to provide reagents for unequivocal differential diagnosis of zoonotic B virus infections, additional mAbs with a broader range of specificities is critical. PMID:28783746
Isolation and Characterization of a Novel Alphaherpesvirus in Fruit Bats
Sasaki, Michihito; Setiyono, Agus; Handharyani, Ekowati; Kobayashi, Shintaro; Rahmadani, Ibenu; Taha, Siswatiana; Adiani, Sri; Subangkit, Mawar; Nakamura, Ichiro; Sawa, Hirofumi
2014-01-01
ABSTRACT Bats are known to harbor emerging RNA viruses. Recent studies have used high-throughput sequencing technology to identify various virus species, including DNA viruses that are harbored by bats; however, little is known about the nature of these potentially novel viruses. Here, we report the characterization of a novel herpesvirus isolated from an Indonesian pteropodid bat. The virus, tentatively named fruit bat alphaherpesvirus 1 (FBAHV1), has a double-stranded DNA genome of 149,459 bp. The phylogenetic analyses suggested that FBAHV1 is phylogenetically grouped with simplexviruses within the subfamily Alphaherpesvirinae. Inoculation of FBAHV1 into laboratory mice caused a lethal infection. Virus infection was observed in lung, liver, and brain tissue. Serological and PCR screening revealed that fruit bats infected with FBAHV1 or its related virus are widely distributed in Indonesia. The identification of FBAHV1 makes a considerable contribution to our understanding of simplexviruses associated with bats. IMPORTANCE Bats are known to harbor emerging viruses, such as lyssaviruses, henipaviruses, severe acute respiratory syndrome-like coronaviruses, and filoviruses. Although alphaherpesviruses are disseminated in humans and other animals, there is little information about their distribution in bats. Here, we isolated a previously unknown alphaherpesvirus from an Indonesian fruit bat. Genome sequence analysis suggested that the virus is a member of the genus Simplexvirus within the subfamily Alphaherpesvirinae, which also includes common human viruses, such as herpes simplex virus 1 and herpes simplex virus 2. FBAHV1 is the first bat-derived alphaherpesvirus whose complete genome has been sequenced. PMID:24942567
Gustavsen, Kate A; Raphael, Bonnie L; Wildes, Martin J; McAloose, Denise; McCann, Colleen M; Hilliard, Julia K; Calle, Paul P
2018-06-01
Langur alphaherpesvirus (HVL), a provisionally named alphaherpesvirus in the Simplexvirus genus, was first identified in 1991 at the Bronx Zoo in wild-origin silvered langurs ( Trachypithecus cristatus) and their descendants. HVL is closely related to B virus ( Macacine alphaherpesvirus 1) based on serologic and genetic data, but its natural history and zoonotic potential remain unknown. A cohort study was undertaken to describe the epidemiology, clinical impact, and potential management implications of this virus in a naturally infected, zoo-based population of silvered langurs. Opportunistic surveillance sampling from 1991 through 2015 resulted in 235 serum samples and 225 mucosal swabs from 75 individuals. A total of 43 individuals (57.3%) were seropositive for HVL within this period. Seroprevalence increased significantly with age, and indirect evidence suggested a peak in transmission at the onset of sexual maturity. These findings were similar to the behavior of other simplexviruses in their adapted hosts. Yearly cumulative incidence declined significantly through the study period, with zero or one new case detected each year from 2007 through 2015. The density of this population decreased within the study period for management reasons unrelated to HVL infection, and a change in age distribution or less-frequent contacts may have contributed to low transmission. In addition, clinical signs of simplexvirus infection were rare, and virus isolation was negative on all mucosal swabs, suggesting that viral shedding was infrequent. Yearly period seroprevalence remained relatively constant with a median of 45.8%, likely because of the extended survival of infected individuals within the population. Maintenance of a naturally occurring, novel virus with unknown zoonotic potential in a zoo population for over 25 yr highlights the importance of biosecurity and biosafety for management of silvered langurs and all primate species.
The first genome sequence of a metatherian herpesvirus: Macropodid herpesvirus 1.
Vaz, Paola K; Mahony, Timothy J; Hartley, Carol A; Fowler, Elizabeth V; Ficorilli, Nino; Lee, Sang W; Gilkerson, James R; Browning, Glenn F; Devlin, Joanne M
2016-01-22
While many placental herpesvirus genomes have been fully sequenced, the complete genome of a marsupial herpesvirus has not been described. Here we present the first genome sequence of a metatherian herpesvirus, Macropodid herpesvirus 1 (MaHV-1). The MaHV-1 viral genome was sequenced using an Illumina MiSeq sequencer, de novo assembly was performed and the genome was annotated. The MaHV-1 genome was 140 kbp in length and clustered phylogenetically with the primate simplexviruses, sharing 67% nucleotide sequence identity with Human herpesviruses 1 and 2. The MaHV-1 genome contained 66 predicted open reading frames (ORFs) homologous to those in other herpesvirus genomes, but lacked homologues of UL3, UL4, UL56 and glycoprotein J. This is the first alphaherpesvirus genome that has been found to lack the UL3 and UL4 homologues. We identified six novel ORFs and confirmed their transcription by RT-PCR. This is the first genome sequence of a herpesvirus that infects metatherians, a taxonomically unique mammalian clade. Members of the Simplexvirus genus are remarkably conserved, so the absence of ORFs otherwise retained in eutherian and avian alphaherpesviruses contributes to our understanding of the Alphaherpesvirinae. Further study of metatherian herpesvirus genetics and pathogenesis provides a unique approach to understanding herpesvirus-mammalian interactions.
Tyler, Shaun D.; Severini, Alberto
2006-01-01
We have sequenced the entire genome of herpesvirus papio 2 (HVP-2; Cercopithecine herpesvirus 16) strain X313, a baboon herpesvirus with close homology to other primate alphaherpesviruses, such as SA8, monkey B virus, and herpes simplex virus (HSV) type 1 and type 2. The genome of HVP-2 is 156,487 bp in length, with an overall GC content of 76.5%. The genome organization is identical to that of the other members of the genus Simplexvirus, with a long and a short unique region, each bordered by inverted repeats which end with an “a” sequence. All of the open reading frames detected in this genome were homologous and colinear with those of SA8 and B virus. The HSV gene RL1 (γ134.5; neurovirulence factor) is not present in HVP-2, as is the case for SA8 and B virus. The HVP-2 genome is 85% homologous to its closest relative, SA8. However, segment-by-segment bootstrap analysis of the genome revealed at least two regions that display closer homology to the corresponding sequences of B virus. The first region comprises the UL41 to UL44 genes, and the second region is located within the UL36 gene. We hypothesize that this localized and defined shift in homology is due to recombination events between an SA8-like progenitor of HVP-2 and a herpesvirus species more closely related to the B virus. Since some of the genes involved in these putative recombination events are determinants of virulence, a comparative analysis of their function may provide insight into the pathogenic mechanism of simplexviruses. PMID:16414998
Tyler, Shaun D; Severini, Alberto
2006-02-01
We have sequenced the entire genome of herpesvirus papio 2 (HVP-2; Cercopithecine herpesvirus 16) strain X313, a baboon herpesvirus with close homology to other primate alphaherpesviruses, such as SA8, monkey B virus, and herpes simplex virus (HSV) type 1 and type 2. The genome of HVP-2 is 156,487 bp in length, with an overall GC content of 76.5%. The genome organization is identical to that of the other members of the genus Simplexvirus, with a long and a short unique region, each bordered by inverted repeats which end with an "a" sequence. All of the open reading frames detected in this genome were homologous and colinear with those of SA8 and B virus. The HSV gene RL1 (gamma(1)34.5; neurovirulence factor) is not present in HVP-2, as is the case for SA8 and B virus. The HVP-2 genome is 85% homologous to its closest relative, SA8. However, segment-by-segment bootstrap analysis of the genome revealed at least two regions that display closer homology to the corresponding sequences of B virus. The first region comprises the UL41 to UL44 genes, and the second region is located within the UL36 gene. We hypothesize that this localized and defined shift in homology is due to recombination events between an SA8-like progenitor of HVP-2 and a herpesvirus species more closely related to the B virus. Since some of the genes involved in these putative recombination events are determinants of virulence, a comparative analysis of their function may provide insight into the pathogenic mechanism of simplexviruses.
The genome of herpesvirus papio 2 is closely related to the genomes of human herpes simplex viruses.
Bigger, John E; Martin, David W
2003-06-01
Infection of baboons (Papio species) with herpesvirus papio 2 (HVP-2) produces a disease that is clinically similar to herpes simplex virus (HSV-1 and HSV-2) infection of humans. The development of a primate model of simplexvirus infection based on HVP-2 would provide a powerful resource to study virus biology and test vaccine strategies. In order to characterize the molecular biology of HVP-2 and justify further development of this model system we have constructed a physical map of the HVP-2 genome. The results of these studies have identified the presence of 26 reading frames that closely resemble HSV homologues. Furthermore, the HVP-2 genome shares a collinear arrangement with the genome of HSV. These studies further validate the development of the HVP-2 model as a surrogate system to study the biology of HSV infections.
Leplina, Olga; Starostina, Nataliya; Zheltova, Olga; Ostanin, Alexandr; Shevela, Ekaterina; Chernykh, Elena
2016-12-01
Recurrent herpes simplex labialis caused predominantly with herpes simplexvirus 1(HSV-1) is a major problem, for which various treatments have minimal impact. Given the important role of the immune system in controlling virus infection, an activation of virus-specific immune responses, in particular,using dendritic cell (DCs) vaccines, seems to be a promising approach for the treatment of patients with frequent recurrences of herpes labialis. The current paper presents the results of a pilot study of the safety and efficacy of DC vaccines in 14 patients with recurrent HSV-1 infections. DCs were generated in presence of GM-CSF and IFN-alpha and were loaded with HSV-1 recombinant viral glycoprotein D (HSV1gD). DCs cells were injected subcutaneously as 2 courses of vaccination during 9 months. Immunotherapy with DCs did not induce any serious side effects and resulted in more than 2-fold reduction in the recurrence rate and significant enhancement of the inter-recurrent time during the 9 months of treatment and subsequent 6-month follow-up period. An obvious clinical improvement was accompanied with an induction of an antigen-specific response to HCV1gD and a normalization of reduced mitogenic responsiveness of mono-nuclear cells. According to long-term survey data (on average 48 months after the beginning of therapy), 87% of respondents reported the decreased incidence of recurrent infection. At this time, most patients (85.7%) responded to HCV1gD stimulation. The data obtained suggests that dendritic cell vaccines may be a promising new approach for the treatment of recurrent labial herpes.
Herpes B Virus Utilizes Human Nectin-1 but Not HVEM or PILRα for Cell-Cell Fusion and Virus Entry
Fan, Qing; Amen, Melanie; Harden, Mallory; Severini, Alberto; Griffiths, Anthony
2012-01-01
To investigate the requirements of herpesvirus entry and fusion, the four homologous glycoproteins necessary for herpes simplex virus (HSV) fusion were cloned from herpes B virus (BV) (or macacine herpesvirus 1, previously known as cercopithecine herpesvirus 1) and cercopithecine herpesvirus 2 (CeHV-2), both related simian simplexviruses belonging to the alphaherpesvirus subfamily. Western blots and cell-based enzyme-linked immunosorbent assay (ELISA) showed that glycoproteins gB, gD, and gH/gL were expressed in whole-cell lysates and on the cell surface. Cell-cell fusion assays indicated that nectin-1, an HSV-1 gD receptor, mediated fusion of cells expressing glycoproteins from both BV and CeHV-2. However, herpesvirus entry mediator (HVEM), another HSV-1 gD receptor, did not facilitate BV- and CeHV-2-induced cell-cell fusion. Paired immunoglobulin-like type 2 receptor alpha (PILRα), an HSV-1 gB fusion receptor, did not mediate fusion of cells expressing glycoproteins from either simian virus. Productive infection with BV was possible only with nectin-1-expressing cells, indicating that nectin-1 mediated entry while HVEM and PILRα did not function as entry receptors. These results indicate that these alphaherpesviruses have differing preferences for entry receptors. The usage of the HSV-1 gD receptor nectin-1 may explain interspecies transfer of the viruses, and altered receptor usage may result in altered virulence, tropism, or pathogenesis in the new host. A heterotypic cell fusion assay resulting in productive fusion may provide insight into interactions that occur to trigger fusion. These findings may be of therapeutic significance for control of deadly BV infections. PMID:22345445
Structural basis of nectin-1 recognition by pseudorabies virus glycoprotein D
Qi, Jianxun; Wu, Lili; Tian, Kegong; Luo, Tingrong; Shi, Yi
2017-01-01
An early and yet indispensable step in the alphaherpesvirus infection is the engagement of host receptors by the viral envelope glycoprotein D (gD). Of the thus-far identified gD receptors, nectin-1 is likely the most effective in terms of its wide usage by multiple alphaherpesviruses for cell entry. The molecular basis of nectin-1 recognition by the gD protein is therefore an interesting scientific question in the alphaherpesvirus field. Previous studies focused on the herpes simplex virus (HSV) of the Simplexvirus genus, for which both the free gD structure and the gD/nectin-1 complex structure were reported at high resolutions. The structural and functional features of other alphaherpesviral gDs, however, remain poorly characterized. In the current study, we systematically studied the characteristics of nectin-1 binding by the gD of a Varicellovirus genus member, the pseudorabies virus (PRV). We first showed that PRV infects host cells via both human and swine nectin-1, and that its gD exhibits similar binding affinities for nectin-1 of the two species. Furthermore, we demonstrated that removal of the PRV gD membrane-proximal residues could significantly increase its affinity for the receptor binding. The structures of PRV gD in the free and the nectin-1-bound states were then solved, revealing a similar overall 3D fold as well as a homologous nectin-1 binding mode to its HSV counterpart. However, several unique features were observed at the binding interface of PRV gD, enabling the viral ligand to utilize different gD residues (from those of HSV) for nectin-1 engagement. These observed binding characteristics were further verified by the mutagenesis study using the key-residue mutants of nectin-1. The structural and functional data obtained in this study, therefore, provide the basis of receptor recognition by PRV gD. PMID:28542478