Non-plaque-forming virions of Modified Vaccinia virus Ankara express viral genes.

PubMed

Lülf, Anna-Theresa; Freudenstein, Astrid; Marr, Lisa; Sutter, Gerd; Volz, Asisa

2016-12-01

In cell culture infections with vaccinia virus the number of counted virus particles is substantially higher than the number of plaques obtained by titration. We found that standard vaccine preparations of recombinant Modified Vaccinia virus Ankara produce only about 20-30% plaque-forming virions in fully permissive cell cultures. To evaluate the biological activity of the non-plaque-forming particles, we generated recombinant viruses expressing fluorescent reporter proteins under transcriptional control of specific viral early and late promoters. Live cell imaging and automated counting by fluorescent microscopy indicated that virtually all virus particles can enter cells and switch on viral gene expression. Although most of the non-plaque-forming infections are arrested at the level of viral early gene expression, we detected activation of late viral transcription in 10-20% of single infected cells. Thus, non-plaque-forming particles are biologically active, and likely contribute to the immunogenicity of vaccinia virus vaccines. Copyright © 2016 Elsevier Inc. All rights reserved.

Myxoma and vaccinia viruses exploit different mechanisms to enter and infect human cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Villa, Nancy Y.; Bartee, Eric; Mohamed, Mohamed R.

2010-06-05

Myxoma (MYXV) and vaccinia (VACV) viruses have recently emerged as potential oncolytic agents that can infect and kill different human cancer cells. Although both are structurally similar, it is unknown whether the pathway(s) used by these poxviruses to enter and cause oncolysis in cancer cells are mechanistically similar. Here, we compared the entry of MYXV and VACV-WR into various human cancer cells and observed significant differences: 1 - low-pH treatment accelerates fusion-mediated entry of VACV but not MYXV, 2 - the tyrosine kinase inhibitor genistein inhibits entry of VACV, but not MYXV, 3 - knockdown of PAK1 revealed that itmore » is required for a late stage event downstream of MYXV entry into cancer cells, whereas PAK1 is required for VACV entry into the same target cells. These results suggest that VACV and MYXV exploit different mechanisms to enter into human cancer cells, thus providing some rationale for their divergent cancer cell tropisms.« less

Construction of live vaccines by using genetically engineered poxviruses: biological activity of recombinant vaccinia virus expressing influenza virus hemagglutinin.

PubMed Central

Panicali, D; Davis, S W; Weinberg, R L; Paoletti, E

1983-01-01

Recombinant vaccinia viruses containing the cloned hemagglutinin (HA) gene from influenza virus were constructed. The biological activity of these poxvirus vectors was demonstrated both in vitro and in vivo. Expression of HA in cells infected with recombinant vaccinia was detected by using specific anti-HA antiserum and 125I-labeled protein A, showing that HA synthesized under the regulation of vaccinia virus was antigenic. Immunization of rabbits with these recombinant poxviruses resulted in the production of antibodies reactive with authentic influenza HA as detected by radioimmunoassay, by inhibition of HA erythrocyte agglutination, and by neutralization of influenza virus infectivity. The production of antibodies directed against influenza HA suggested that the HA gene expressed in vaccinia is immunogenic. These data indicate the potential of genetically engineered poxviruses for use as generic live vaccine vehicles that have both human and veterinary applications. Images PMID:6310573

Inhibition of vaccinia virus maturation by zinc chloride.

PubMed Central

Katz, E; Margalith, E

1981-01-01

Zinc chloride (0.1 mM) inhibited by 96.4% the growth of vaccinia virus in HeLa cells. Approximately 50% inhibition in formation of particles that sedimented in sucrose gradients similarly to vaccinia virions occurred in the presence of zinc ions. Whereas the synthesis of the viral deoxyribonucleic acid was not affected by zinc chloride, a decrease in the overall synthesis of viral polypeptides and inhibition of the cleavage of precursors to the core polypeptides were observed. Images PMID:7347557

Studies on the serological relationships between avian pox, sheep pox, goat pox and vaccinia viruses

PubMed Central

Uppal, P. K.; Nilakantan, P. R.

1970-01-01

By using neutralization, complement fixation and immunogel-diffusion tests, it has been demonstrated that cross-reactions occur between various avian pox viruses and between sheep pox and goat pox viruses. No such reactions were demonstrated between avian pox viruses and vaccinia virus or between avian pox and sheep pox and goat pox viruses. Furthermore, no serological relationship was demonstrable between vaccinia virus and sheep pox and goat pox viruses. PMID:4989854

Vaccinia virus, herpes simplex virus, and carcinogens induce DNA amplification in a human cell line and support replication of a helpervirus dependent parvovirus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schlehofer, J.R.; Ehrbar, M.; zur Hausen, H.

1986-07-15

The SV40-transformed human kidney cell line, NB-E, amplifies integrated as well as episomal SV40 DNA upon treatment with chemical (DMBA) or physical (uv irradiation) carcinogens (initiators) as well as after infection with herpes simplex virus (HSV) type 1 or with vaccinia virus. In addition it is shown that vaccinia virus induces SV40 DNA amplification also in the SV40-transformed Chinese hamster embryo cell line, CO631. These findings demonstrate that human cells similar to Chinese hamster cells amplify integrated DNA sequences after treatment with carcinogens or infection with specific viruses. Furthermore, a poxvirus--vaccinia virus--similar to herpes group viruses induces DNA amplification. Asmore » reported for other systems, the vaccinia virus-induced DNA amplification in NB-E cells is inhibited by coinfection with adeno-associated virus (AAV) type 5. This is in line with previous studies on inhibition of carcinogen- or HSV-induced DNA amplification in CO631 cells. The experiments also demonstrate that vaccinia virus, in addition to herpes and adenoviruses acts as a helper virus for replication and structural antigen synthesis of AAV-5 in NB-E cells.« less

Susceptibility of Vaccinia Virus to Chemical Disinfectants

PubMed Central

de Oliveira, Tércia Moreira Ludolfo; Rehfeld, Izabelle Silva; Coelho Guedes, Maria Isabel Maldonado; Ferreira, Jaqueline Maria Siqueira; Kroon, Erna Geessien; Lobato, Zélia Inês Portela

2011-01-01

Vaccinia virus (VACV) is the cause of bovine vaccinia (BV), an emerging zoonotic disease that affects dairy cows and milkers. Some chemical disinfectants have been used on farms affected by BV to disinfect cow teats and milkers' hands. To date, there is no information about the efficacy of disinfectants against VACV. Therefore, this study aimed to assess the virucidal activity of some active disinfectants commonly used in the field. Sodium hypochlorite, quaternary ammonium combined with chlorhexidine, and quaternary ammonium combined with glutaraldehyde were effective in inactivating the virus at all concentrations tested. Iodine and quaternary ammonium as the only active component were partially effective. The presence of bovine feces as organic matter and light decreased the effectiveness of sodium hypochlorite. These results show that an appropriated disinfection and asepsis of teats and hands may be helpful in the control and prevention of BV and other infections with VACV. PMID:21734141

Analysis of variola and vaccinia virus neutralization assays for smallpox vaccines.

PubMed

Hughes, Christine M; Newman, Frances K; Davidson, Whitni B; Olson, Victoria A; Smith, Scott K; Holman, Robert C; Yan, Lihan; Frey, Sharon E; Belshe, Robert B; Karem, Kevin L; Damon, Inger K

2012-07-01

Possible smallpox reemergence drives research for third-generation vaccines that effectively neutralize variola virus. A comparison of neutralization assays using different substrates, variola and vaccinia (Dryvax and modified vaccinia Ankara [MVA]), showed significantly different 90% neutralization titers; Dryvax underestimated while MVA overestimated variola neutralization. Third-generation vaccines may rely upon neutralization as a correlate of protection.

Expression of the Bacillus anthracis protective antigen gene by baculovirus and vaccinia virus recombinants.

PubMed Central

Iacono-Connors, L C; Schmaljohn, C S; Dalrymple, J M

1990-01-01

The gene encoding Bacillus anthracis protective antigen (PA) was modified by site-directed mutagenesis, subcloned into baculovirus and vaccinia virus plasmid transfer vectors (pAcYM1 and pSC-11, respectively), and inserted via homologous recombinations into baculovirus Autographa californica nuclear polyhedrosis virus or vaccinia virus (strains WR and Connaught). Expression of PA was detected in both systems by immunofluorescence assays with antisera from rabbits immunized with B. anthracis PA. Western blot (immunoblot) analysis showed that the expressed product of both systems was slightly larger (86 kilodaltons) than B. anthracis-produced PA (83.5 kilodaltons). Analysis of trypsin digests of virus-expressed and authentic PA suggested that the size difference was due to the presence of a signal sequence remaining with the virus-expressed protein. Immunization of mice with either recombinant baculovirus-infected Spodoptera frugiperda cells or with vaccinia virus recombinants elicited a high-titer, anti-PA antibody response. Images PMID:2105271

Can vaccinia virus be replaced by MVA virus for testing virucidal activity of chemical disinfectants?

PubMed

Rabenau, Holger F; Rapp, Ingrid; Steinmann, Jochen

2010-06-23

Vaccinia virus strain Lister Elstree (VACV) is a test virus in the DVV/RKI guidelines as representative of the stable enveloped viruses. Since the potential risk of laboratory-acquired infections with VACV persists and since the adverse effects of vaccination with VACV are described, the replacement of VACV by the modified vaccinia Ankara strain (MVA) was studied by testing the activity of different chemical biocides in three German laboratories. The inactivating properties of different chemical biocides (peracetic acid, aldehydes and alcohols) were tested in a quantitative suspension test according to the DVV/RKI guideline. All tests were performed with a protein load of 10% fetal calf serum with both viruses in parallel using different concentrations and contact times. Residual virus was determined by endpoint dilution method. The chemical biocides exhibited similar virucidal activity against VACV and MVA. In three cases intra-laboratory differences were determined between VACV and MVA - 40% (v/v) ethanol and 30% (v/v) isopropanol are more active against MVA, whereas MVA seems more stable than VACV when testing with 0.05% glutardialdehyde. Test accuracy across the three participating laboratories was high. Remarkably inter-laboratory differences in the reduction factor were only observed in two cases. Our data provide valuable information for the replacement of VACV by MVA for testing chemical biocides and disinfectants. Because MVA does not replicate in humans this would eliminate the potential risk of inadvertent inoculation with vaccinia virus and disease in non-vaccinated laboratory workers.

Septins suppress the release of vaccinia virus from infected cells.

PubMed

Pfanzelter, Julia; Mostowy, Serge; Way, Michael

2018-06-19

Septins are conserved components of the cytoskeleton that play important roles in many fundamental cellular processes including division, migration, and membrane trafficking. Septins can also inhibit bacterial infection by forming cage-like structures around pathogens such as Shigella We found that septins are recruited to vaccinia virus immediately after its fusion with the plasma membrane during viral egress. RNA interference-mediated depletion of septins increases virus release and cell-to-cell spread, as well as actin tail formation. Live cell imaging reveals that septins are displaced from the virus when it induces actin polymerization. Septin loss, however, depends on the recruitment of the SH2/SH3 adaptor Nck, but not the activity of the Arp2/3 complex. Moreover, it is the recruitment of dynamin by the third Nck SH3 domain that displaces septins from the virus in a formin-dependent fashion. Our study demonstrates that septins suppress vaccinia release by "entrapping" the virus at the plasma membrane. This antiviral effect is overcome by dynamin together with formin-mediated actin polymerization. © 2018 Pfanzelter et al.

One-step selection of Vaccinia virus-binding DNA aptamers by MonoLEX

PubMed Central

Nitsche, Andreas; Kurth, Andreas; Dunkhorst, Anna; Pänke, Oliver; Sielaff, Hendrik; Junge, Wolfgang; Muth, Doreen; Scheller, Frieder; Stöcklein, Walter; Dahmen, Claudia; Pauli, Georg; Kage, Andreas

2007-01-01

Background As a new class of therapeutic and diagnostic reagents, more than fifteen years ago RNA and DNA aptamers were identified as binding molecules to numerous small compounds, proteins and rarely even to complete pathogen particles. Most aptamers were isolated from complex libraries of synthetic nucleic acids by a process termed SELEX based on several selection and amplification steps. Here we report the application of a new one-step selection method (MonoLEX) to acquire high-affinity DNA aptamers binding Vaccinia virus used as a model organism for complex target structures. Results The selection against complete Vaccinia virus particles resulted in a 64-base DNA aptamer specifically binding to orthopoxviruses as validated by dot blot analysis, Surface Plasmon Resonance, Fluorescence Correlation Spectroscopy and real-time PCR, following an aptamer blotting assay. The same oligonucleotide showed the ability to inhibit in vitro infection of Vaccinia virus and other orthopoxviruses in a concentration-dependent manner. Conclusion The MonoLEX method is a straightforward procedure as demonstrated here for the identification of a high-affinity DNA aptamer binding Vaccinia virus. MonoLEX comprises a single affinity chromatography step, followed by subsequent physical segmentation of the affinity resin and a single final PCR amplification step of bound aptamers. Therefore, this procedure improves the selection of high affinity aptamers by reducing the competition between aptamers of different affinities during the PCR step, indicating an advantage for the single-round MonoLEX method. PMID:17697378

Modulating Vaccinia Virus Immunomodulators to Improve Immunological Memory

PubMed Central

Torres, Alice A.; Smith, Geoffrey L.

2018-01-01

The increasing frequency of monkeypox virus infections, new outbreaks of other zoonotic orthopoxviruses and concern about the re-emergence of smallpox have prompted research into developing antiviral drugs and better vaccines against these viruses. This article considers the genetic engineering of vaccinia virus (VACV) to enhance vaccine immunogenicity and safety. The virulence, immunogenicity and protective efficacy of VACV strains engineered to lack specific immunomodulatory or host range proteins are described. The ultimate goal is to develop safer and more immunogenic VACV vaccines that induce long-lasting immunological memory. PMID:29495547

Vaccinia Virus Recombinant Expressing Herpes Simplex Virus Type 1 Glycoprotein D Prevents Latent Herpes in Mice

NASA Astrophysics Data System (ADS)

Cremer, Kenneth J.; Mackett, Michael; Wohlenberg, Charles; Notkins, Abner Louis; Moss, Bernard

1985-05-01

In humans, herpes simplex virus causes a primary infection and then often a latent ganglionic infection that persists for life. Because these latent infections can recur periodically, vaccines are needed that can protect against both primary and latent herpes simplex infections. Infectious vaccinia virus recombinants that contain the herpes simplex virus type 1 (HSV-1) glycoprotein D gene under control of defined early or late vaccinia virus promoters were constructed. Tissue culture cells infected with these recombinant viruses synthesized a glycosylated protein that had the same mass (60,000 daltons) as the glycoprotein D produced by HSV-1. Immunization of mice with one of these recombinant viruses by intradermal, subcutaneous, or intraperitoneal routes resulted in the production of antibodies that neutralized HSV-1 and protected the mice against subsequent lethal challenge with HSV-1 or HSV-2. Immunization with the recombinant virus also protected the majority of the mice against the development of a latent HSV-1 infection of the trigeminal ganglia. This is the first demonstration that a genetically engineered vaccine can prevent the development of latency.

Vaccinia Virus Recombinants: Expression of VSV Genes and Protective Immunization of Mice and Cattle

NASA Astrophysics Data System (ADS)

Mackett, M.; Yilma, T.; Rose, J. K.; Moss, B.

1985-01-01

Vesicular stomatitis virus (VSV) causes a contagious disease of horses, cattle, and pigs. When DNA copies of messenger RNA's for the G or N proteins of VSV were linked to a vaccinia virus promoter and inserted into the vaccinia genome, the recombinants retained infectivity and synthesized VSV polypeptides. After intradermal vaccination with live recombinant virus expressing the G protein, mice produced VSV-neutralizing antibodies and were protected against lethal encephalitis upon intravenous challenge with VSV. In cattle, the degree of protection against intradermalingually injected VSV was correlated with the level of neutralizing antibody produced following vaccination.

Modified Vaccinia Ankara Virus Vaccination Provides Long-Term Protection against Nasal Rabbitpox Virus Challenge.

PubMed

Jones, Dorothy I; McGee, Charles E; Sample, Christopher J; Sempowski, Gregory D; Pickup, David J; Staats, Herman F

2016-07-01

Modified vaccinia Ankara virus (MVA) is a smallpox vaccine candidate. This study was performed to determine if MVA vaccination provides long-term protection against rabbitpox virus (RPXV) challenge, an animal model of smallpox. Two doses of MVA provided 100% protection against a lethal intranasal RPXV challenge administered 9 months after vaccination. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Resistance to Human Respiratory Syncytial Virus (RSV) Infection Induced by Immunization of Cotton Rats with a Recombinant Vaccinia Virus Expressing the RSV G Glycoprotein

NASA Astrophysics Data System (ADS)

Elango, Narayanasamy; Prince, Gregory A.; Murphy, Brian R.; Venkatesan, Sundararajan; Chanock, Robert M.; Moss, Bernard

1986-03-01

A cDNA copy of the G glycoprotein gene of human respiratory syncytial virus (RSV) was placed under control of a vaccinia virus promoter and inserted into the thymidine kinase locus of the vaccinia virus genome. The recombinant vaccinia virus retained infectivity and expressed a 93-kDa protein that migrated with the authentic RSV G glycoprotein upon polyacrylamide gel electrophoresis. Glycosylation of the expressed protein and transport to the cell surface were demonstrated in the absence of other RSV proteins. Cotton rats that were inoculated intradermally with the infectious recombinant virus produced serum antibody to the G glycoprotein that neutralized RSV in vitro. Furthermore, the vaccinated animals were resistant to lower respiratory tract infection upon intranasal inoculation with RSV and had reduced titers of RSV in the nose.

Identification of vaccinia virus epitope-specific HLA-A*0201-restricted T cells and comparative analysis of smallpox vaccines

PubMed Central

Drexler, Ingo; Staib, Caroline; Kastenmüller, Wolfgang; Stevanović, Stefan; Schmidt, Burkhard; Lemonnier, François A.; Rammensee, Hans-Georg; Busch, Dirk H.; Bernhard, Helga; Erfle, Volker; Sutter, Gerd

2003-01-01

Despite worldwide eradication of naturally occurring variola virus, smallpox remains a potential threat to both civilian and military populations. New, safe smallpox vaccines are being developed, and there is an urgent need for methods to evaluate vaccine efficacy after immunization. Here we report the identification of an immunodominant HLA-A*0201-restricted epitope that is recognized by cytotoxic CD8+ T cells and conserved among Orthopoxvirus species including variola virus. This finding has permitted analysis and monitoring of epitope-specific T cell responses after immunization and demonstration of the identified T cell specificity in an A*0201-positive human donor. Vaccination of transgenic mice allowed us to compare the immunogenicity of several vaccinia viruses including highly attenuated, replication-deficient modified vaccinia virus Ankara (MVA). MVA vaccines elicited levels of CD8+ T cell responses that were comparable to those induced by the replication-competent vaccinia virus strains. Finally, we demonstrate that MVA vaccination is fully protective against a lethal respiratory challenge with virulent vaccinia virus strain Western Reserve. Our data provide a basis to rationally estimate immunogenicity of safe, second-generation poxvirus vaccines and suggest that MVA may be a suitable candidate. PMID:12518065

Intracellular Transport of Vaccinia Virus in HeLa Cells Requires WASH-VPEF/FAM21-Retromer Complexes and Recycling Molecules Rab11 and Rab22

PubMed Central

Hsiao, Jye-Chian; Chu, Li-Wei; Lo, Yung-Tsun; Lee, Sue-Ping; Chen, Tzu-Jung; Huang, Cheng-Yen

2015-01-01

ABSTRACT Vaccinia virus, the prototype of the Orthopoxvirus genus in the family Poxviridae, infects a wide range of cell lines and animals. Vaccinia mature virus particles of the WR strain reportedly enter HeLa cells through fluid-phase endocytosis. However, the intracellular trafficking process of the vaccinia mature virus between cellular uptake and membrane fusion remains unknown. We used live imaging of single virus particles with a combination of various cellular vesicle markers, to track fluorescent vaccinia mature virus particle movement in cells. Furthermore, we performed functional interference assays to perturb distinct vesicle trafficking processes in order to delineate the specific route undertaken by vaccinia mature virus prior to membrane fusion and virus core uncoating in cells. Our results showed that vaccinia virus traffics to early endosomes, where recycling endosome markers Rab11 and Rab22 are recruited to participate in subsequent virus trafficking prior to virus core uncoating in the cytoplasm. Furthermore, we identified WASH-VPEF/FAM21-retromer complexes that mediate endosome fission and sorting of virus-containing vesicles prior to virus core uncoating in the cytoplasm. IMPORTANCE Vaccinia mature virions of the WR strain enter HeLa cells through fluid phase endocytosis. We previously demonstrated that virus-containing vesicles are internalized into phosphatidylinositol 3-phosphate positive macropinosomes, which are then fused with Rab5-positive early endosomes. However, the subsequent process of sorting the virion-containing vesicles prior to membrane fusion remains unclear. We dissected the intracellular trafficking pathway of vaccinia mature virions in cells up to virus core uncoating in cytoplasm. We show that vaccinia mature virions first travel to early endosomes. Subsequent trafficking events require the important endosome-tethered protein VPEF/FAM21, which recruits WASH and retromer protein complexes to the endosome. There, the complex

Lister vaccine strain of vaccinia virus armed with the endostatin-angiostatin fusion gene: an oncolytic virus superior to dl1520 (ONYX-015) for human head and neck cancer.

PubMed

Tysome, James R; Wang, Pengju; Alusi, Ghassan; Briat, Arnaud; Gangeswaran, Rathi; Wang, Jiwei; Bhakta, Vipul; Fodor, Istvan; Lemoine, Nick R; Wang, Yaohe

2011-09-01

Oncolytic viral therapy represents a promising strategy for the treatment of head and neck squamous cell carcinoma (HNSCC), with dl1520 (ONYX-015) the most widely used oncolytic adenovirus in clinical trials. This study aimed to determine the effectiveness of the Lister vaccine strain of vaccinia virus as well as a vaccinia virus armed with the endostatin-angiostatin fusion gene (VVhEA) as a novel therapy for HNSCC and to compare them with dl1520. The potency and replication of the Lister strain and VVhEA and the expression and function of the fusion protein were determined in human HNSCC cells in vitro and in vivo. Finally, the efficacy of VVhEA was compared with dl1520 in vivo in a human HNSCC model. The Lister vaccine strain of vaccinia virus was more effective than the adenovirus against all HNSCC cell lines tested in vitro. Although the potency of VVhEA was attenuated in vitro, the expression and function of the endostatin-angiostatin fusion protein was confirmed in HNSCC models both in vitro and in vivo. This novel vaccinia virus (VVhEA) demonstrated superior antitumor potency in vivo compared with both dl1520 and the control vaccinia virus. This study suggests that the Lister strain vaccinia virus armed with an endostatin-angiostatin fusion gene may be a potential therapeutic agent for HNSCC.

Vaccinia Virus Induces Rapid Necrosis in Keratinocytes by a STAT3-Dependent Mechanism

PubMed Central

He, Yong; Fisher, Robert; Chowdhury, Soma; Sultana, Ishrat; Pereira, Claudia P.; Bray, Mike; Reed, Jennifer L.

2014-01-01

Rationale Humans with a dominant negative mutation in STAT3 are susceptible to severe skin infections, suggesting an essential role for STAT3 signaling in defense against cutaneous pathogens. Methods To focus on innate antiviral defenses in keratinocytes, we used a standard model of cutaneous infection of severe combined immunodeficient mice with the current smallpox vaccine, ACAM-2000. In parallel, early events post-infection with the smallpox vaccine ACAM-2000 were investigated in cultured keratinocytes of human and mouse origin. Results Mice treated topically with a STAT3 inhibitor (Stattic) developed larger vaccinia lesions with higher virus titers and died more rapidly than untreated controls. Cultured human and murine keratinocytes infected with ACAM-2000 underwent rapid necrosis, but when treated with Stattic or with inhibitors of RIP1 kinase or caspase-1, they survived longer, produced higher titers of virus, and showed reduced activation of type I interferon responses and inflammatory cytokines release. Treatment with inhibitors of RIP1 kinase and STAT3, but not caspase-1, also reduced the inflammatory response of keratinocytes to TLR ligands. Vaccinia growth properties in Vero cells, which are known to be defective in some antiviral responses, were unaffected by inhibition of RIP1K, caspase-1, or STAT3. Conclusions Our findings indicate that keratinocytes suppress the replication and spread of vaccinia virus by undergoing rapid programmed cell death, in a process requiring STAT3. These data offer a new framework for understanding susceptibility to skin infection in patients with STAT3 mutations. Interventions which promote prompt necroptosis/pyroptosis of infected keratinocytes may reduce risks associated with vaccination with live vaccinia virus. PMID:25419841

Horizontal study of vaccinia virus infections in an endemic area: epidemiologic, phylogenetic and economic aspects.

PubMed

Assis, Felipe L; Franco-Luiz, Ana Paula M; Paim, Luis M; Oliveira, Graziele P; Pereira, Alexandre F; de Almeida, Gabriel M F; Figueiredo, Leandra B; Tanus, Adriano; Trindade, Giliane S; Ferreira, Paulo P; Kroon, Erna G; Abrahão, Jônatas S

2015-11-01

Vaccinia virus (VACV), the etiological agent of bovine vaccinia (BV), is widespread in Brazil and present in most of the milk-producing regions. We conducted a horizontal study of BV in Bahia, a state of Brazil in which the production of milk is increasing. During 2011, human and bovine clinical samples were collected during outbreaks for BV diagnosis, virus isolation and molecular analysis. We collected data for epidemiological inferences. Vaccinia virus was detected in 87.7% of the analyzed outbreaks, highlighting the effective circulation of VACV in Bahia. The molecular data showed the spreading of group 1 Brazilian VACV to Bahia. We observed a seasonal profile of BV, with its peak in the drier and cooler season. Manual milking was observed in 96 % of the visited properties, showing its importance to viral spread in herds. Under-notification of BV, ineffective animal trade surveillance, and bad milking practices have contributed to the spread of VACV in Brazil.

Sensitization with vaccinia virus encoding H5N1 hemagglutinin restores immune potential against H5N1 influenza virus.

PubMed

Yasui, Fumihiko; Itoh, Yasushi; Ikejiri, Ai; Kitabatake, Masahiro; Sakaguchi, Nobuo; Munekata, Keisuke; Shichinohe, Shintaro; Hayashi, Yukiko; Ishigaki, Hirohito; Nakayama, Misako; Sakoda, Yoshihiro; Kida, Hiroshi; Ogasawara, Kazumasa; Kohara, Michinori

2016-11-28

H5N1 highly pathogenic avian influenza (H5N1 HPAI) virus causes elevated mortality compared with seasonal influenza viruses like H1N1 pandemic influenza (H1N1 pdm) virus. We identified a mechanism associated with the severe symptoms seen with H5N1 HPAI virus infection. H5N1 HPAI virus infection induced a decrease of dendritic cell number in the splenic extrafollicular T-cell zone and impaired formation of the outer layers of B-cell follicles, resulting in insufficient levels of antibody production after infection. However, in animals vaccinated with a live recombinant vaccinia virus expressing the H5 hemagglutinin, infection with H5N1 HPAI virus induced parafollicular dendritic cell accumulation and efficient antibody production. These results indicate that a recombinant vaccinia encoding H5 hemagglutinin gene does not impair dendritic cell recruitment and can be a useful vaccine candidate.

Modified Vaccinia Virus Ankara: History, Value in Basic Research, and Current Perspectives for Vaccine Development.

PubMed

Volz, A; Sutter, G

2017-01-01

Safety tested Modified Vaccinia virus Ankara (MVA) is licensed as third-generation vaccine against smallpox and serves as a potent vector system for development of new candidate vaccines against infectious diseases and cancer. Historically, MVA was developed by serial tissue culture passage in primary chicken cells of vaccinia virus strain Ankara, and clinically used to avoid the undesirable side effects of conventional smallpox vaccination. Adapted to growth in avian cells MVA lost the ability to replicate in mammalian hosts and lacks many of the genes orthopoxviruses use to conquer their host (cell) environment. As a biologically well-characterized mutant virus, MVA facilitates fundamental research to elucidate the functions of poxvirus host-interaction factors. As extremely safe viral vectors MVA vaccines have been found immunogenic and protective in various preclinical infection models. Multiple recombinant MVA currently undergo clinical testing for vaccination against human immunodeficiency viruses, Mycobacterium tuberculosis or Plasmodium falciparum. The versatility of the MVA vector vaccine platform is readily demonstrated by the swift development of experimental vaccines for immunization against emerging infections such as the Middle East Respiratory Syndrome. Recent advances include promising results from the clinical testing of recombinant MVA-producing antigens of highly pathogenic avian influenza virus H5N1 or Ebola virus. This review summarizes our current knowledge about MVA as a unique strain of vaccinia virus, and discusses the prospects of exploiting this virus as research tool in poxvirus biology or as safe viral vector vaccine to challenge existing and future bottlenecks in vaccinology. © 2017 Elsevier Inc. All rights reserved.

How Does Vaccinia Virus Interfere With Interferon?

PubMed

Smith, Geoffrey L; Talbot-Cooper, Callum; Lu, Yongxu

2018-01-01

Interferons (IFNs) are secreted glycoproteins that are produced by cells in response to virus infection and other stimuli and induce an antiviral state in cells bearing IFN receptors. In this way, IFNs restrict virus replication and spread before an adaptive immune response is developed. Viruses are very sensitive to the effects of IFNs and consequently have evolved many strategies to interfere with interferon. This is particularly well illustrated by poxviruses, which have large dsDNA genomes and encode hundreds of proteins. Vaccinia virus is the prototypic poxvirus and expresses many proteins that interfere with IFN and are considered in this review. These proteins act either inside or outside the cell and within the cytoplasm or nucleus. They function by restricting the production of IFN by blocking the signaling pathways leading to transcription of IFN genes, stopping IFNs binding to their receptors, blocking IFN-induced signal transduction leading to expression of interferon-stimulated genes (ISGs), or inhibiting the antiviral activity of ISG products. © 2018 Elsevier Inc. All rights reserved.

Structure and Assembly of Intracellular Mature Vaccinia Virus: Thin-Section Analyses

PubMed Central

Griffiths, Gareth; Roos, Norbert; Schleich, Sybille; Locker, Jacomine Krijnse

2001-01-01

In the preceding study (see accompanying paper), we showed by a variety of different techniques that intracellular mature vaccinia virus (vaccinia IMV) is unexpectedly complex in its structural organization and that this complexity also extends to the underlying viral core, which is highly folded. With that analysis as a foundation, we now present different thin-section electron microscopy approaches for analyzing the IMV and the processes by which it is assembled in infected HeLa cells. We focus on conventional epoxy resin thin sections as well as cryosections to describe key intermediates in the assembly process. We took advantage of streptolysin O's ability to selectively permeabilize the plasma membrane of infected cells to improve membrane contrast, and we used antibodies against bone fide integral membrane proteins of the virus to unequivocally identify membrane profiles in thin sections. All of the images presented here can be rationalized with respect to the model put forward for the assembly of the IMV in the accompanying paper. PMID:11602745

Live-vaccinia virus encapsulation in pH-sensitive polymer increases safety of a reservoir-targeted Lyme disease vaccine by targeting gastrointestinal release.

PubMed

Kern, Aurelie; Zhou, Chensheng W; Jia, Feng; Xu, Qiaobing; Hu, Linden T

2016-08-31

The incidence of Lyme disease has continued to rise despite attempts to control its spread. Vaccination of zoonotic reservoirs of human pathogens has been successfully used to decrease the incidence of rabies in raccoons and foxes. We have previously reported on the efficacy of a vaccinia virus vectored vaccine to reduce carriage of Borrelia burgdorferi in reservoir mice and ticks. One potential drawback to vaccinia virus vectored vaccines is the risk of accidental infection of humans. To reduce this risk, we developed a process to encapsulate vaccinia virus with a pH-sensitive polymer that inactivates the virus until it is ingested and dissolved by stomach acids. We demonstrate that the vaccine is inactive both in vitro and in vivo until it is released from the polymer. Once released from the polymer by contact with an acidic pH solution, the virus regains infectivity. Vaccination with coated vaccinia virus confers protection against B. burgdorferi infection and reduction in acquisition of the pathogen by naïve feeding ticks. Copyright © 2016. Published by Elsevier Ltd.

Bioluminescence imaging of a tumor-selective, thymidine kinase-defective vaccinia virus Guang9 strain after intratumoral or intraperitoneal administration in mice

PubMed Central

Ding, Yuedi; Fan, Jun; Deng, Lili; Peng, Ying; Zhang, Jue; Huang, Biao

2017-01-01

Vaccinia virus has been used as an oncolytic virus because of its capacity to preferentially infect tumors rather than normal tissues. The vaccinia Tian Tan strain, used as a vaccine against smallpox for millions of people in China, is a promising candidate for cancer therapy. In this study, we constructed an attenuated Tian Tan strain of Guang9 with a disrupted thymidine kinase gene to enhance tumor selectivity and an inserted firefly luciferase to monitor the viral distribution by in vivo bioluminescence imaging. Living animal imaging confirmed the high specificity of vaccinia Guang9 for tumor targeting after intratumoral and intraperitoneal administration. In addition, the vaccinia Guang9 strain produced higher in vivo luciferase activity and endured longer in immunocompromised nude mice than in immunocompetent C57BL/6 mice, all of which had been tumor-challenged. The luciferase activity and viral titers in excised tissues confirmed these conclusions. These data provide evidence for the safety and efficacy of the clinical application of vaccinia virus, which would be a promising approach for cancer therapy. PMID:29179469

Animal Movement and Establishment of Vaccinia Virus Cantagalo Strain in Amazon Biome, Brazil

PubMed Central

Quixabeira-Santos, Jociane Cristina; Medaglia, Maria Luiza G.; Pescador, Caroline A.

2011-01-01

To understand the emergence of vaccinia virus Cantagalo strain in the Amazon biome of Brazil, during 2008–2010 we conducted a molecular and epidemiologic survey of poxvirus outbreaks. Data indicate that animal movement was the major cause of virus dissemination within Rondônia State, leading to the establishment and spread of this pathogen. PMID:21470472

Active vaccination with vaccinia virus A33 protects mice against lethal vaccinia and ectromelia viruses but not against cowpoxvirus; elucidation of the specific adaptive immune response.

PubMed

Paran, Nir; Lustig, Shlomo; Zvi, Anat; Erez, Noam; Israely, Tomer; Melamed, Sharon; Politi, Boaz; Ben-Nathan, David; Schneider, Paula; Lachmi, Batel; Israeli, Ofir; Stein, Dana; Levin, Reuven; Olshevsky, Udy

2013-07-10

Vaccinia virus protein A33 (A33VACV) plays an important role in protection against orthopoxviruses, and hence is included in experimental multi-subunit smallpox vaccines. In this study we show that single-dose vaccination with recombinant Sindbis virus expressing A33VACV, is sufficient to protect mice against lethal challenge with vaccinia virus WR (VACV-WR) and ectromelia virus (ECTV) but not against cowpox virus (CPXV), a closely related orthopoxvirus. Moreover, a subunit vaccine based on the cowpox virus A33 ortholog (A33CPXV) failed to protect against cowpox and only partially protected mice against VACV-WR challenge. We mapped regions of sequence variation between A33VACV and A33CPXVand analyzed the role of such variations in protection. We identified a single protective region located between residues 104-120 that harbors a putative H-2Kd T cell epitope as well as a B cell epitope - a target for the neutralizing antibody MAb-1G10 that blocks spreading of extracellular virions. Both epitopes in A33CPXV are mutated and predicted to be non-functional. Whereas vaccination with A33VACV did not induce in-vivo CTL activity to the predicted epitope, inhibition of virus spread in-vitro, and protection from lethal VACV challenge pointed to the B cell epitope highlighting the critical role of residue L118 and of adjacent compensatory residues in protection. This epitope's critical role in protection, as well as its modifications within the orthopoxvirus genus should be taken in context with the failure of A33 to protect against CPXV as demonstrated here. These findings should be considered when developing new subunit vaccines and monoclonal antibody based therapeutics against orthopoxviruses, especially variola virus, the etiologic agent of smallpox.

Active vaccination with vaccinia virus A33 protects mice against lethal vaccinia and ectromelia viruses but not against cowpoxvirus; elucidation of the specific adaptive immune response

PubMed Central

2013-01-01

Vaccinia virus protein A33 (A33VACV) plays an important role in protection against orthopoxviruses, and hence is included in experimental multi-subunit smallpox vaccines. In this study we show that single-dose vaccination with recombinant Sindbis virus expressing A33VACV, is sufficient to protect mice against lethal challenge with vaccinia virus WR (VACV-WR) and ectromelia virus (ECTV) but not against cowpox virus (CPXV), a closely related orthopoxvirus. Moreover, a subunit vaccine based on the cowpox virus A33 ortholog (A33CPXV) failed to protect against cowpox and only partially protected mice against VACV-WR challenge. We mapped regions of sequence variation between A33VACV and A33CPXVand analyzed the role of such variations in protection. We identified a single protective region located between residues 104–120 that harbors a putative H-2Kd T cell epitope as well as a B cell epitope - a target for the neutralizing antibody MAb-1G10 that blocks spreading of extracellular virions. Both epitopes in A33CPXV are mutated and predicted to be non-functional. Whereas vaccination with A33VACV did not induce in-vivo CTL activity to the predicted epitope, inhibition of virus spread in-vitro, and protection from lethal VACV challenge pointed to the B cell epitope highlighting the critical role of residue L118 and of adjacent compensatory residues in protection. This epitope’s critical role in protection, as well as its modifications within the orthopoxvirus genus should be taken in context with the failure of A33 to protect against CPXV as demonstrated here. These findings should be considered when developing new subunit vaccines and monoclonal antibody based therapeutics against orthopoxviruses, especially variola virus, the etiologic agent of smallpox. PMID:23842430

Enhanced Efficacy of Cidofovir Combined with Vaccinia Immune Globulin in Treating Progressive Cutaneous Vaccinia Virus Infections in Immunosuppressed Hairless Mice

PubMed Central

Dagley, Ashley; Downs, Brittney; Hagloch, Joseph; Tarbet, E. Bart

2014-01-01

The treatment of progressive vaccinia in individuals has involved antiviral drugs, such as cidofovir (CDV), brincidofovir, and/or tecovirimat, combined with vaccinia immune globulin (VIG). VIG is costly, and its supply is limited, so sparing the use of VIG during treatment is an important objective. VIG sparing was modeled in immunosuppressed mice by maximizing the treatment benefits of CDV combined with VIG to determine the effective treatments that delayed the time to death, reduced cutaneous lesion severity, and/or decreased tissue viral titers. SKH-1 hairless mice immunosuppressed with cyclophosphamide and hairless SCID mice (SHO strain) were infected cutaneously with vaccinia virus. Monotherapy, dual combinations (CDV plus VIG), or triple therapy (topical CDV, parenteral CDV, and VIG) were initiated 2 days postinfection and were given every 3 to 4 days through day 11. The efficacy assessment included survival rate, cutaneous lesion severity, and viral titers. Delays in the time to death and the reduction in lesion severity occurred in the following order of efficacy: triple therapy had greater efficacy than double combinations (CDV plus VIG or topical plus parenteral CDV), which had greater efficacy than VIG alone. Parenteral administration of CDV or VIG was necessary to suppress virus titers in internal organs (liver, lung, and spleen). The skin viral titers were significantly reduced by triple therapy only. The greatest efficacy was achieved by triple therapy. In humans, this regimen should translate to a faster cure rate, thus sparing the amount of VIG used for treatment. PMID:25385098

Preliminary analysis of murine cytotoxic T cell responses to the proteins of the flavivirus Kunjin using vaccinia virus expression.

PubMed

Parrish, C R; Coia, G; Hill, A; Müllbacher, A; Westaway, E G; Blanden, R V

1991-07-01

A series of recombinant vaccinia viruses expressing various parts of the entire Kunjin virus (KUN) coding region was used to analyse the cytotoxic T (Tc) cell responses to KUN. CBA/H mice inoculated with KUN or West Nile virus were shown to develop responses to KUN or various vaccinia virus expression constructs in either primary cytotoxic assays, or after secondary stimulation of the Tc cells in vitro with KUN antigens. Tc cells from CBA mice showed the strongest response to target cells infected with recombinant vaccinia viruses expressing parts of the KUN NS3 and NS4A proteins, and only a weak response to the other structural or non-structural proteins. Further analysis of deleted versions of the NS3-NS4A region showed that the main epitope recognized was derived from a sequence of 99 amino acids spanning parts of NS3 and NS4A. No other major epitopes were detected by Tc cells from CBA mice in the remaining 3333 amino acids of the KUN polypeptide.

Effect of Interferon, Polyacrylic Acid, and Polymethacrylic Acid on Tail Lesions in Mice Infected with Vaccinia Virus

PubMed Central

De Clercq, E.; De Somer, P.

1968-01-01

Intravenous inoculation of mice with vaccinia virus produced characteristic lesions of the tail surface which were suppressed by intraperitoneal administration of interferon and polyacrylic acid (PAA). Polymethacrylic acid (PMAA) stimulated the formation of vaccinia virus lesions. For full activity, both interferon and PAA must be given prior to infection. PAA was still significantly effective at small dose levels (3 mg/kg) and achieved protection for at least 4 weeks. Protection increased with increasing molecular weight of the polymer. The mode of action of PAA is discussed. PMID:5676405

Postexposure prevention of progressive vaccinia in SCID mice treated with vaccinia immune globulin.

PubMed

Fisher, R W; Reed, J L; Snoy, P J; Mikolajczyk, M G; Bray, M; Scott, D E; Kennedy, M C

2011-01-01

A recently reported case of progressive vaccinia (PV) in an immunocompromised patient has refocused attention on this condition. Uniformly fatal prior to the licensure of vaccinia immune globulin (VIG) in 1978, PV was still fatal in about half of VIG-treated patients overall, with a greater mortality rate in infants and children. Additional therapies would be needed in the setting of a smallpox bioterror event, since mass vaccination following any variola virus release would inevitably result in exposure of immunocompromised people through vaccination or contact with vaccinees. Well-characterized animal models of disease can support the licensure of new products when human studies are not ethical or feasible, as in the case of PV. We chose vaccinia virus-scarified SCID mice to model PV. As in immunocompromised humans, vaccinia virus-scarified SCID animals develop enlarging primary lesions with minimal or no inflammation, eventual distal virus spread, and lethal outcomes if left untreated. Postexposure treatment with VIG slowed disease progression, caused local lesion regression, and resulted in the healthy survival of most of the mice for more than 120 days. Combination treatment with VIG and topical cidofovir also resulted in long-term disease-free survival of most of the animals, even when initiated 7 days postinfection. These results support the possibility that combination treatments may be effective in humans and support using this SCID model of PV to test new antibody therapies and combination therapies and to provide further insights into the pathogenesis and treatment of PV.

Elements in the Development of a Production Process for Modified Vaccinia Virus Ankara

PubMed Central

Jordan, Ingo; Lohr, Verena; Genzel, Yvonne; Reichl, Udo; Sandig, Volker

2013-01-01

The production of several viral vaccines depends on chicken embryo fibroblasts or embryonated chicken eggs. To replace this logistically demanding substrate, we created continuous anatine suspension cell lines (CR and CR.pIX), developed chemically-defined media, and established production processes for different vaccine viruses. One of the processes investigated in greater detail was developed for modified vaccinia virus Ankara (MVA). MVA is highly attenuated for human recipients and an efficient vector for reactogenic expression of foreign genes. Because direct cell-to-cell spread is one important mechanism for vaccinia virus replication, cultivation of MVA in bioreactors is facilitated if cell aggregates are induced after infection. This dependency may be the mechanism behind our observation that a novel viral genotype (MVA-CR) accumulates with serial passage in suspension cultures. Sequencing of a major part of the genomic DNA of the new strain revealed point mutations in three genes. We hypothesize that these changes confer an advantage because they may allow a greater fraction of MVA-CR viruses to escape the host cells for infection of distant targets. Production and purification of MVA-based vaccines may be simplified by this combination of designed avian cell line, chemically defined media and the novel virus strain. PMID:27694766

Elements in the Development of a Production Process for Modified Vaccinia Virus Ankara.

PubMed

Jordan, Ingo; Lohr, Verena; Genzel, Yvonne; Reichl, Udo; Sandig, Volker

2013-11-01

The production of several viral vaccines depends on chicken embryo fibroblasts or embryonated chicken eggs. To replace this logistically demanding substrate, we created continuous anatine suspension cell lines (CR and CR.pIX), developed chemically-defined media, and established production processes for different vaccine viruses. One of the processes investigated in greater detail was developed for modified vaccinia virus Ankara (MVA). MVA is highly attenuated for human recipients and an efficient vector for reactogenic expression of foreign genes. Because direct cell-to-cell spread is one important mechanism for vaccinia virus replication, cultivation of MVA in bioreactors is facilitated if cell aggregates are induced after infection. This dependency may be the mechanism behind our observation that a novel viral genotype (MVA-CR) accumulates with serial passage in suspension cultures. Sequencing of a major part of the genomic DNA of the new strain revealed point mutations in three genes. We hypothesize that these changes confer an advantage because they may allow a greater fraction of MVA-CR viruses to escape the host cells for infection of distant targets. Production and purification of MVA-based vaccines may be simplified by this combination of designed avian cell line, chemically defined media and the novel virus strain.

Recombinant Modified Vaccinia Virus Ankara Generating Ebola Virus-Like Particles.

PubMed

Schweneker, Marc; Laimbacher, Andrea S; Zimmer, Gert; Wagner, Susanne; Schraner, Elisabeth M; Wolferstätter, Michael; Klingenberg, Marieken; Dirmeier, Ulrike; Steigerwald, Robin; Lauterbach, Henning; Hochrein, Hubertus; Chaplin, Paul; Suter, Mark; Hausmann, Jürgen

2017-06-01

There are currently no approved therapeutics or vaccines to treat or protect against the severe hemorrhagic fever and death caused by Ebola virus (EBOV). Ebola virus-like particles (EBOV VLPs) consisting of the matrix protein VP40, the glycoprotein (GP), and the nucleoprotein (NP) are highly immunogenic and protective in nonhuman primates against Ebola virus disease (EVD). We have constructed a modified vaccinia virus Ankara-Bavarian Nordic (MVA-BN) recombinant coexpressing VP40 and GP of EBOV Mayinga and the NP of Taï Forest virus (TAFV) (MVA-BN-EBOV-VLP) to launch noninfectious EBOV VLPs as a second vaccine modality in the MVA-BN-EBOV-VLP-vaccinated organism. Human cells infected with either MVA-BN-EBOV-VLP or MVA-BN-EBOV-GP showed comparable GP expression levels and transport of complex N-glycosylated GP to the cell surface. Human cells infected with MVA-BN-EBOV-VLP produced large amounts of EBOV VLPs that were decorated with GP spikes but excluded the poxviral membrane protein B5, thus resembling authentic EBOV particles. The heterologous TAFV NP enhanced EBOV VP40-driven VLP formation with efficiency similar to that of the homologous EBOV NP in a transient-expression assay, and both NPs were incorporated into EBOV VLPs. EBOV GP-specific CD8 T cell responses were comparable between MVA-BN-EBOV-VLP- and MVA-BN-EBOV-GP-immunized mice. The levels of EBOV GP-specific neutralizing and binding antibodies, as well as GP-specific IgG1/IgG2a ratios induced by the two constructs, in mice were also similar, raising the question whether the quality rather than the quantity of the GP-specific antibody response might be altered by an EBOV VLP-generating MVA recombinant. IMPORTANCE The recent outbreak of Ebola virus (EBOV), claiming more than 11,000 lives, has underscored the need to advance the development of safe and effective filovirus vaccines. Virus-like particles (VLPs), as well as recombinant viral vectors, have proved to be promising vaccine candidates. Modified

The vaccinia virus E6 protein influences virion protein localization during virus assembly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Condit, Richard C., E-mail: condit@mgm.ufl.edu; Moussatche, Nissin

2015-08-15

Vaccinia virus mutants in which expression of the virion core protein gene E6R is repressed are defective in virion morphogenesis. E6 deficient infections fail to properly package viroplasm into viral membranes, resulting in an accumulation of empty immature virions and large aggregates of viroplasm. We have used immunogold electron microscopy and immunofluorescence confocal microscopy to assess the intracellular localization of several virion structural proteins and enzymes during E6R mutant infections. We find that during E6R mutant infections virion membrane proteins and virion transcription enzymes maintain a normal localization within viral factories while several major core and lateral body proteins accumulatemore » in aggregated virosomes. The results support a model in which vaccinia virions are assembled from at least three substructures, the membrane, the viroplasm and a “pre-nucleocapsid”, and that the E6 protein is essential for maintaining proper localization of the seven-protein complex and the viroplasm during assembly. - Highlights: • Mutation of E6 disrupts association of viral membranes with viral core proteins • Mutation of E6 does not perturb viral membrane biosynthesis • Mutation of E6 does not perturb localization of viral transcription enzymes • Mutation of E6 causes mis-localization and aggregation of viral core proteins • Vaccinia assembly uses three subassemblies: membranes, viroplasm, prenucleocapsid.« less

Effect of the Deletion of Genes Encoding Proteins of the Extracellular Virion Form of Vaccinia Virus on Vaccine Immunogenicity and Protective Effectiveness in the Mouse Model

PubMed Central

Meseda, Clement A.; Campbell, Joseph; Kumar, Arunima; Garcia, Alonzo D.; Merchlinsky, Michael; Weir, Jerry P.

2013-01-01

Antibodies to both infectious forms of vaccinia virus, the mature virion (MV) and the enveloped virion (EV), as well as cell-mediated immune response appear to be important for protection against smallpox. EV virus particles, although more labile and less numerous than MV, are important for dissemination and spread of virus in infected hosts and thus important in virus pathogenesis. The importance of the EV A33 and B5 proteins for vaccine induced immunity and protection in a murine intranasal challenge model was evaluated by deletion of both the A33R and B5R genes in a vaccine-derived strain of vaccinia virus. Deletion of either A33R or B5R resulted in viruses with a small plaque phenotype and reduced virus yields, as reported previously, whereas deletion of both EV protein-encoding genes resulted in a virus that formed small infection foci that were detectable and quantifiable only by immunostaining and an even more dramatic decrease in total virus yield in cell culture. Deletion of B5R, either as a single gene knockout or in the double EV gene knockout virus, resulted in a loss of EV neutralizing activity, but all EV gene knockout viruses still induced a robust neutralizing activity against the vaccinia MV form of the virus. The effect of elimination of A33 and/or B5 on the protection afforded by vaccination was evaluated by intranasal challenge with a lethal dose of either vaccinia virus WR or IHD-J, a strain of vaccinia virus that produces relatively higher amounts of EV virus. The results from multiple experiments, using a range of vaccination doses and virus challenge doses, and using mortality, morbidity, and virus dissemination as endpoints, indicate that the absence of A33 and B5 have little effect on the ability of a vaccinia vaccine virus to provide protection against a lethal intranasal challenge in a mouse model. PMID:23785523

Thy1+ Nk Cells from Vaccinia Virus-Primed Mice Confer Protection against Vaccinia Virus Challenge in the Absence of Adaptive Lymphocytes

PubMed Central

Gillard, Geoffrey O.; Bivas-Benita, Maytal; Hovav, Avi-Hai; Grandpre, Lauren E.; Panas, Michael W.; Seaman, Michael S.; Haynes, Barton F.; Letvin, Norman L.

2011-01-01

While immunological memory has long been considered the province of T- and B- lymphocytes, it has recently been reported that innate cell populations are capable of mediating memory responses. We now show that an innate memory immune response is generated in mice following infection with vaccinia virus, a poxvirus for which no cognate germline-encoded receptor has been identified. This immune response results in viral clearance in the absence of classical adaptive T and B lymphocyte populations, and is mediated by a Thy1+ subset of natural killer (NK) cells. We demonstrate that immune protection against infection from a lethal dose of virus can be adoptively transferred with memory hepatic Thy1+ NK cells that were primed with live virus. Our results also indicate that, like classical immunological memory, stronger innate memory responses form in response to priming with live virus than a highly attenuated vector. These results demonstrate that a defined innate memory cell population alone can provide host protection against a lethal systemic infection through viral clearance. PMID:21829360

Homology between DNA polymerases of poxviruses, herpesviruses, and adenoviruses: nucleotide sequence of the vaccinia virus DNA polymerase gene.

PubMed Central

Earl, P L; Jones, E V; Moss, B

1986-01-01

A 5400-base-pair segment of the vaccinia virus genome was sequenced and an open reading frame of 938 codons was found precisely where the DNA polymerase had been mapped by transfer of a phosphonoacetate-resistance marker. A single nucleotide substitution changing glycine at position 347 to aspartic acid accounts for the drug resistance of the mutant vaccinia virus. The 5' end of the DNA polymerase mRNA was located 80 base pairs before the methionine codon initiating the open reading frame. Correspondence between the predicted Mr 108,577 polypeptide and the 110,000 purified enzyme indicates that little or no proteolytic processing occurs. Extensive homology, extending over 435 amino acids, was found upon comparing the DNA polymerase of vaccinia virus and DNA polymerase of Epstein-Barr virus. A highly conserved sequence of 14 amino acids in the carboxyl-terminal regions of the above DNA polymerases is also present at a similar location in adenovirus DNA polymerase. This structure, which is predicted to form a turn flanked by beta-pleated sheets, may form part of an essential binding or catalytic site that accounts for its presence in DNA polymerases of poxviruses, herpesviruses, and adenoviruses. Images PMID:3012524

Role of sulfatide in vaccinia virus infection.

PubMed

Perino, Julien; Foo, Chwan Hong; Spehner, Daniele; Cohen, Gary H; Eisenberg, Roselyn J; Crance, Jean-Marc; Favier, Anne-Laure

2011-07-01

Vaccinia virus (VACV) was used as a surrogate of variola virus (genus Orthopoxvirus), the causative agent of smallpox, to study orthopoxvirus infection. VACV infects cells via attachment and fusion of the viral membrane with the host cell membrane. Glycosphingolipids, expressed in multiple organs, are major components of lipid rafts and have been associated with the infectious route of several pathogens. We demonstrate that the VACV-WR (VACV Western-Reserve strain) displays no binding to Cer (ceramide) or to Gal-Cer (galactosylceramide), but binds to a natural sulfated derivative of these molecules: the Sulf (sulfatide) 3' sulfogalactosylceramide. The interaction between Sulf and VACV-WR resulted in a time-dependent inhibition of virus infection. Virus cell attachment was the crucial step inhibited by Sulf. Electron microscopy showed that SUVs (small unilamellar vesicles) enriched in Sulf bound to VACV particles. Both the A27 and L5 viral membrane proteins were shown to interact with Sulf, indicating that they could be the major viral ligands for Sulf. Soluble Sulf was successful in preventing mortality, but not morbidity, in a lethal mouse model infection with VACV-WR. Together the results suggest that Sulf could play a role as an alternate receptor for VACV-WR and probably other Orthopoxviruses.

Genetically Engineered Vaccinia Viruses As Agents for Cancer Treatment, Imaging, and Transgene Delivery

PubMed Central

Haddad, Dana

2017-01-01

Despite advances in technology, the formidable challenge of treating cancer, especially if advanced, still remains with no significant improvement in survival rates, even with the most common forms of cancer. Oncolytic viral therapies have shown great promise for the treatment of various cancers, with the possible advantages of stronger treatment efficacy compared to conventional therapy due to higher tumor selectivity, and less toxicity. They are able to preferentially and selectively propagate in cancer cells, consequently destroying tumor tissue mainly via cell lysis, while leaving non-cancerous tissues unharmed. Several wild-type and genetically engineered vaccinia virus (VACV) strains have been tested in both preclinical and clinical trials with promising results. Greater understanding and advancements in molecular biology have enabled the generation of genetically engineered oncolytic viruses for safer and more efficacious treatment, including arming VACVs with cytokines and immunostimulatory molecules, anti-angiogenic agents, and enzyme prodrug therapy, in addition to combining VACVs with conventional external and systemic radiotherapy, chemotherapy, immunotherapy, and other virus strains. Furthermore, novel oncolytic vaccinia virus strains have been generated that express reporter genes for the tracking and imaging of viral therapy and monitoring of therapeutic response. Further study is needed to unlock VACVs’ full potential as part of the future of cancer therapy. PMID:28589082

A protein-based smallpox vaccine protects mice from vaccinia and ectromelia virus challenges when given as a prime and single boost

PubMed Central

Xiao, Yuhong; Aldaz-Carroll, Lydia; Ortiz, Alexandra M.; Whitbeck, J. Charles; Alexander, Edward; Lou, Huan; Davis, J. Heather L.; Braciale, Thomas J.; Eisenberg, Roselyn J.; Cohen, Gary H.; Isaacs, Stuart N.

2007-01-01

The heightened concern about the intentional release of variola virus has led to the need to develop safer smallpox vaccines. While subunit vaccine strategies are safer than live virus vaccines, subunit vaccines have been hampered by the need for multiple boosts to confer optimal protection. Here we developed a protein-based subunit vaccine strategy that provides rapid protection in mouse models of orthopoxvirus infections after a prime and single boost. Mice vaccinated with vaccinia virus envelope proteins from the mature virus (MV) and extracellular virus (EV) adjuvanted with CpG-ODN and alum were protected from lethal intranasal challenge with vaccinia virus and the mouse-specific ectromelia virus. Organs from mice vaccinated with three proteins (A33, B5 and L1) and then sacrificed after challenge contained significantly lower titers of virus when compared to control groups of mice that were not vaccinated or that received sub-optimal formulations of the vaccine. Sera from groups of mice obtained prior to challenge had neutralizing activity against the MV and also inhibited comet formation indicating anti-EV activity. Long-term partial protection was also seen in mice challenged with vaccinia virus 6 months after initial vaccinations. Thus, this work represents a step toward the development of a practical subunit smallpox vaccine. PMID:17098336

Vaccinia Virus Vaccines: Past, Present and Future

PubMed Central

Jacobs, Bertram L.; Langland, Jeffrey O.; Kibler, Karen V.; Denzler, Karen L.; White, Stacy D.; Holechek, Susan A.; Wong, Shukmei; Huynh, Trung; Baskin, Carole R.

2009-01-01

Vaccinia virus (VACV) has been used more extensively for human immunization than any other vaccine. For almost two centuries, VACV was employed to provide cross-protection against variola virus, the causative agent of smallpox, until the disease was eradicated in the late 1970s. Since that time, continued research on VACV has produced a number of modified vaccines with improved safety profiles. Attenuation has been achieved through several strategies, including sequential passage in an alternative host, deletion of specific genes or genetic engineering of viral genes encoding immunomodulatory proteins. Some highly attenuated third- and fourth-generation VACV vaccines are now being considered for stockpiling against a possible re-introduction of smallpox through bioterrorism. Researchers have also taken advantage of the ability of the VACV genome to accommodate additional genetic material to produce novel vaccines against a wide variety of infectious agents, including a recombinant VACV encoding the rabies virus glycoprotein that is administered orally to wild animals. This review provides an in-depth examination of these successive generations of VACV vaccines, focusing on how the understanding of poxviral replication and viral gene function permits the deliberate modification of VACV immunogenicity and virulence. PMID:19563829

Detection of Vaccinia virus in blood and faeces of experimentally infected cows.

PubMed

Guedes, M I M C; Rehfeld, I S; de Oliveira, T M L; Assis, F L; Matos, A C D; Abrahão, J S; Kroon, E G; Lobato, Z I P

2013-12-01

Bovine vaccinia (BV), a zoonosis caused by Vaccinia virus (VACV), affects dairy cattle and milkers, causing economic, veterinary and human health impacts. Despite such impacts, there are no experimental studies about the pathogenesis of BV in cows to assess whether there is a systemic spread of the virus and whether there are different ways of VACV shedding. Trying to answer some of these questions, a study was proposed using experimental inoculation of VACV in cows. All experimentally infected cows developed lesions compatible with VACV infection in cattle. Two of the six animals presented VACV DNA in blood and faecal samples, starting at the 2nd and the 3rd day post-infection (d.p.i.), respectively, and lasting until the 36th d.p.i., in an intermittent way. This study provides new evidence that VACV can be detected in blood and faeces of infected cows, suggesting that BV could be a systemic disease, and also bringing new information about the epidemiology and pathogenesis of BV. © 2012 Blackwell Verlag GmbH.

DNA and modified vaccinia virus Ankara vaccines encoding multiple cytotoxic and helper T-lymphocyte epitopes of human immunodeficiency virus type 1 (HIV-1) are safe but weakly immunogenic in HIV-1-uninfected, vaccinia virus-naive adults.

PubMed

Gorse, Geoffrey J; Newman, Mark J; deCamp, Allan; Hay, Christine Mhorag; De Rosa, Stephen C; Noonan, Elizabeth; Livingston, Brian D; Fuchs, Jonathan D; Kalams, Spyros A; Cassis-Ghavami, Farah L

2012-05-01

We evaluated a DNA plasmid-vectored vaccine and a recombinant modified vaccinia virus Ankara vaccine (MVA-mBN32), each encoding cytotoxic and helper T-lymphocyte epitopes of human immunodeficiency virus type 1 (HIV-1) in a randomized, double-blinded, placebo-controlled trial in 36 HIV-1-uninfected adults using a heterologous prime-boost schedule. HIV-1-specific cellular immune responses, measured as interleukin-2 and/or gamma interferon production, were induced in 1 (4%) of 28 subjects after the first MVA-mBN32 immunization and in 3 (12%) of 25 subjects after the second MVA-mBN32 immunization. Among these responders, polyfunctional T-cell responses, including the production of tumor necrosis factor alpha and perforin, were detected. Vaccinia virus-specific antibodies were induced to the MVA vector in 27 (93%) of 29 and 26 (93%) of 28 subjects after the first and second immunizations with MVA-mBN32. These peptide-based vaccines were safe but were ineffective at inducing HIV-1-specific immune responses and induced much weaker responses than MVA vaccines expressing the entire open reading frames of HIV-1 proteins.

Analysis of the L1 gene product of human papillomavirus type 16 by expression in a vaccinia virus recombinant.

PubMed

Browne, H M; Churcher, M J; Stanley, M A; Smith, G L; Minson, A C

1988-06-01

The L1 open reading frame of human papillomavirus type 16 (HPV16) has been expressed in vaccinia virus under the control of both the 7.5K early and late promoter, and the 4b major late promoter. Antibodies to a beta-galactosidase fusion protein containing a C-terminal portion of the HPV16 L1 gene product were used to compare the levels of L1 expression in the two recombinants, and showed that greater levels of expression were obtained when the gene was placed under the control of the 4b late promoter. Immunofluorescence studies revealed a nuclear location of the L1 gene product when expressed in vaccinia virus. Antibodies to the beta-galactosidase fusion protein detected a major polypeptide species of 57K and a minor species of 64K in Western blots of recombinant-infected cell lysates. The 64K species was not detected when cells were infected in the presence of tunicamycin, indicating that the primary translation product of the HPV16 L1 open reading frame is modified by N-linked glycosylation when expressed in vaccinia virus. Whereas antibodies to HPV16 L1 fusion proteins and to a peptide containing amino acids from the C terminus of HPV16 L1 reacted well in Western blots with the HPV16 L1 target expressed in vaccinia virus, no reactivity was observed with antibodies to bovine papillomavirus type 1 particles or to a HPV6b fusion protein.

Functional hyper-IL-6 from vaccinia virus-colonized tumors triggers platelet formation and helps to alleviate toxicity of mitomycin C enhanced virus therapy

PubMed Central

2012-01-01

Background Combination of oncolytic vaccinia virus therapy with conventional chemotherapy has shown promise for tumor therapy. However, side effects of chemotherapy including thrombocytopenia, still remain problematic. Methods Here, we describe a novel approach to optimize combination therapy of oncolytic virus and chemotherapy utilizing virus-encoding hyper-IL-6, GLV-1h90, to reduce chemotherapy-associated side effects. Results We showed that the hyper-IL-6 cytokine was successfully produced by GLV-1h90 and was functional both in cell culture as well as in tumor-bearing animals, in which the cytokine-producing vaccinia virus strain was well tolerated. When combined with the chemotherapeutic mitomycin C, the anti-tumor effect of the oncolytic virotherapy was significantly enhanced. Moreover, hyper-IL-6 expression greatly reduced the time interval during which the mice suffered from chemotherapy-induced thrombocytopenia. Conclusion Therefore, future clinical application would benefit from careful investigation of additional cytokine treatment to reduce chemotherapy-induced side effects. PMID:22236378

Modified vaccinia virus Ankara encoding influenza virus hemagglutinin induces heterosubtypic immunity in macaques.

PubMed

Florek, Nicholas W; Weinfurter, Jason T; Jegaskanda, Sinthujan; Brewoo, Joseph N; Powell, Tim D; Young, Ginger R; Das, Subash C; Hatta, Masato; Broman, Karl W; Hungnes, Olav; Dudman, Susanne G; Kawaoka, Yoshihiro; Kent, Stephen J; Stinchcomb, Dan T; Osorio, Jorge E; Friedrich, Thomas C

2014-11-01

Current influenza virus vaccines primarily aim to induce neutralizing antibodies (NAbs). Modified vaccinia virus Ankara (MVA) is a safe and well-characterized vector for inducing both antibody and cellular immunity. We evaluated the immunogenicity and protective efficacy of MVA encoding influenza virus hemagglutinin (HA) and/or nucleoprotein (NP) in cynomolgus macaques. Animals were given 2 doses of MVA-based vaccines 4 weeks apart and were challenged with a 2009 pandemic H1N1 isolate (H1N1pdm) 8 weeks after the last vaccination. MVA-based vaccines encoding HA induced potent serum antibody responses against homologous H1 or H5 HAs but did not stimulate strong T cell responses prior to challenge. However, animals that received MVA encoding influenza virus HA and/or NP had high frequencies of virus-specific CD4(+) and CD8(+) T cell responses within the first 7 days of H1N1pdm infection, while animals vaccinated with MVA encoding irrelevant antigens did not. We detected little or no H1N1pdm replication in animals that received vaccines encoding H1 (homologous) HA, while a vaccine encoding NP from an H5N1 isolate afforded no protection. Surprisingly, H1N1pdm viral shedding was reduced in animals vaccinated with MVA encoding HA and NP from an H5N1 isolate. This reduced shedding was associated with cross-reactive antibodies capable of mediating antibody-dependent cellular cytotoxicity (ADCC) effector functions. Our results suggest that ADCC plays a role in cross-protective immunity against influenza. Vaccines optimized to stimulate cross-reactive antibodies with ADCC function may provide an important measure of protection against emerging influenza viruses when NAbs are ineffective. Current influenza vaccines are designed to elicit neutralizing antibodies (NAbs). Vaccine-induced NAbs typically are effective but highly specific for particular virus strains. Consequently, current vaccines are poorly suited for preventing the spread of newly emerging pandemic viruses

Modified Vaccinia Virus Ankara Encoding Influenza Virus Hemagglutinin Induces Heterosubtypic Immunity in Macaques

PubMed Central

Florek, Nicholas W.; Weinfurter, Jason T.; Jegaskanda, Sinthujan; Brewoo, Joseph N.; Powell, Tim D.; Young, Ginger R.; Das, Subash C.; Hatta, Masato; Broman, Karl W.; Hungnes, Olav; Dudman, Susanne G.; Kawaoka, Yoshihiro; Kent, Stephen J.; Stinchcomb, Dan T.

2014-01-01

ABSTRACT Current influenza virus vaccines primarily aim to induce neutralizing antibodies (NAbs). Modified vaccinia virus Ankara (MVA) is a safe and well-characterized vector for inducing both antibody and cellular immunity. We evaluated the immunogenicity and protective efficacy of MVA encoding influenza virus hemagglutinin (HA) and/or nucleoprotein (NP) in cynomolgus macaques. Animals were given 2 doses of MVA-based vaccines 4 weeks apart and were challenged with a 2009 pandemic H1N1 isolate (H1N1pdm) 8 weeks after the last vaccination. MVA-based vaccines encoding HA induced potent serum antibody responses against homologous H1 or H5 HAs but did not stimulate strong T cell responses prior to challenge. However, animals that received MVA encoding influenza virus HA and/or NP had high frequencies of virus-specific CD4+ and CD8+ T cell responses within the first 7 days of H1N1pdm infection, while animals vaccinated with MVA encoding irrelevant antigens did not. We detected little or no H1N1pdm replication in animals that received vaccines encoding H1 (homologous) HA, while a vaccine encoding NP from an H5N1 isolate afforded no protection. Surprisingly, H1N1pdm viral shedding was reduced in animals vaccinated with MVA encoding HA and NP from an H5N1 isolate. This reduced shedding was associated with cross-reactive antibodies capable of mediating antibody-dependent cellular cytotoxicity (ADCC) effector functions. Our results suggest that ADCC plays a role in cross-protective immunity against influenza. Vaccines optimized to stimulate cross-reactive antibodies with ADCC function may provide an important measure of protection against emerging influenza viruses when NAbs are ineffective. IMPORTANCE Current influenza vaccines are designed to elicit neutralizing antibodies (NAbs). Vaccine-induced NAbs typically are effective but highly specific for particular virus strains. Consequently, current vaccines are poorly suited for preventing the spread of newly emerging

Safety and biodistribution of a double-deleted oncolytic vaccinia virus encoding CD40 ligand in laboratory Beagles

PubMed Central

Autio, Karoliina; Knuuttila, Anna; Kipar, Anja; Pesonen, Sari; Guse, Kilian; Parviainen, Suvi; Rajamäki, Minna; Laitinen-Vapaavuori, Outi; Vähä-Koskela, Markus; Kanerva, Anna; Hemminki, Akseli

2014-01-01

We evaluated adverse events, biodistribution and shedding of oncolytic vaccinia virus encoding CD40 ligand in two Beagles, in preparation for a phase 1 trial in canine cancer patients. Dog 1 received one dose of vaccinia virus and was euthanized 24 hours afterwards, while dog 2 received virus four times once weekly and was euthanized 7 days after that. Dogs were monitored for adverse events and underwent a detailed postmortem examination. Blood, saliva, urine, feces, and organs were collected for virus detection. Dog 1 had mild fever and lethargy while dog 2 experienced a possible seizure 5.5 hours after first virus administration. Viral DNA declined quickly in the blood after virus administration in both dogs but was still detectable 1 week later by quantitative polymerase chain reaction. Only samples taken directly after virus infusion contained infectious virus. Small amounts of viral DNA, but no infectious virus, were detected in a few saliva and urine samples. Necropsies did not reveal any relevant pathological changes and virus DNA was detected mainly in the spleen. The dogs in the study did not have cancer, and thus adverse events could be more common and viral load higher in dogs with tumors which allow viral amplification. PMID:27119092

Analysis of canine herpesvirus gB, gC and gD expressed by a recombinant vaccinia virus.

PubMed

Xuan, X; Kojima, A; Murata, T; Mikami, T; Otsuka, H

1997-01-01

The genes encoding the canine herpesvirus (CHV) glycoprotein B (gB), gC and gD homologues have been reported already. However, products of these genes have not been identified yet. Previously, we have identified three CHV glycoproteins, gp 145/112, gp80 and gp47 using a panel of monoclonal antibodies (MAbs). To determine which CHV glycoprotein corresponds to gB, gC or gD, the putative genes of gB, gC, and gD of CHV were inserted into the thymidine kinase gene of vaccinia virus LC16mO strain under the control of the early-late promoter for the vaccinia virus 7.5-kilodalton polypeptide. We demonstrated here that gp145/112, gp80 and gp47 were the translation products of the CHV gB, gC and gD genes, respectively. The antigenic authenticity of recombinant gB, gC and gD were confirmed by a panel of MAbs specific for each glycoprotein produced in CHV-infected cells. Immunization of mice with these recombinants produced high titers of neutralizing antibodies against CHV. These results suggest that recombinant vaccinia viruses expressing CHV gB, gC and gD may be useful to develop a vaccine to control CHV infection.

Nucleotide sequence of a cluster of early and late genes in a conserved segment of the vaccinia virus genome.

PubMed Central

Plucienniczak, A; Schroeder, E; Zettlmeissl, G; Streeck, R E

1985-01-01

The nucleotide sequence of a 7.6 kb vaccinia DNA segment from a genomic region conserved among different orthopox virus has been determined. This segment contains a tight cluster of 12 partly overlapping open reading frames most of which can be correlated with previously identified early and late proteins and mRNAs. Regulatory signals used by vaccinia virus have been studied. Presumptive promoter regions are rich in A, T and carry the consensus sequences TATA and AATAA spaced at 20-24 base pairs. Tandem repeats of a CTATTC consensus sequence are proposed to be involved in the termination of early transcription. PMID:2987815

Immunization of Pigs by DNA Prime and Recombinant Vaccinia Virus Boost To Identify and Rank African Swine Fever Virus Immunogenic and Protective Proteins.

PubMed

Jancovich, James K; Chapman, Dave; Hansen, Debra T; Robida, Mark D; Loskutov, Andrey; Craciunescu, Felicia; Borovkov, Alex; Kibler, Karen; Goatley, Lynnette; King, Katherine; Netherton, Christopher L; Taylor, Geraldine; Jacobs, Bertram; Sykes, Kathryn; Dixon, Linda K

2018-04-15

African swine fever virus (ASFV) causes an acute hemorrhagic fever in domestic pigs, with high socioeconomic impact. No vaccine is available, limiting options for control. Although live attenuated ASFV can induce up to 100% protection against lethal challenge, little is known of the antigens which induce this protective response. To identify additional ASFV immunogenic and potentially protective antigens, we cloned 47 viral genes in individual plasmids for gene vaccination and in recombinant vaccinia viruses. These antigens were selected to include proteins with different functions and timing of expression. Pools of up to 22 antigens were delivered by DNA prime and recombinant vaccinia virus boost to groups of pigs. Responses of immune lymphocytes from pigs to individual recombinant proteins and to ASFV were measured by interferon gamma enzyme-linked immunosorbent spot (ELISpot) assays to identify a subset of the antigens that consistently induced the highest responses. All 47 antigens were then delivered to pigs by DNA prime and recombinant vaccinia virus boost, and pigs were challenged with a lethal dose of ASFV isolate Georgia 2007/1. Although pigs developed clinical and pathological signs consistent with acute ASFV, viral genome levels were significantly reduced in blood and several lymph tissues in those pigs immunized with vectors expressing ASFV antigens compared with the levels in control pigs. IMPORTANCE The lack of a vaccine limits the options to control African swine fever. Advances have been made in the development of genetically modified live attenuated ASFV that can induce protection against challenge. However, there may be safety issues relating to the use of these in the field. There is little information about ASFV antigens that can induce a protective immune response against challenge. We carried out a large screen of 30% of ASFV antigens by delivering individual genes in different pools to pigs by DNA immunization prime and recombinant vaccinia

Immunization of Pigs by DNA Prime and Recombinant Vaccinia Virus Boost To Identify and Rank African Swine Fever Virus Immunogenic and Protective Proteins

PubMed Central

2018-01-01

ABSTRACT African swine fever virus (ASFV) causes an acute hemorrhagic fever in domestic pigs, with high socioeconomic impact. No vaccine is available, limiting options for control. Although live attenuated ASFV can induce up to 100% protection against lethal challenge, little is known of the antigens which induce this protective response. To identify additional ASFV immunogenic and potentially protective antigens, we cloned 47 viral genes in individual plasmids for gene vaccination and in recombinant vaccinia viruses. These antigens were selected to include proteins with different functions and timing of expression. Pools of up to 22 antigens were delivered by DNA prime and recombinant vaccinia virus boost to groups of pigs. Responses of immune lymphocytes from pigs to individual recombinant proteins and to ASFV were measured by interferon gamma enzyme-linked immunosorbent spot (ELISpot) assays to identify a subset of the antigens that consistently induced the highest responses. All 47 antigens were then delivered to pigs by DNA prime and recombinant vaccinia virus boost, and pigs were challenged with a lethal dose of ASFV isolate Georgia 2007/1. Although pigs developed clinical and pathological signs consistent with acute ASFV, viral genome levels were significantly reduced in blood and several lymph tissues in those pigs immunized with vectors expressing ASFV antigens compared with the levels in control pigs. IMPORTANCE The lack of a vaccine limits the options to control African swine fever. Advances have been made in the development of genetically modified live attenuated ASFV that can induce protection against challenge. However, there may be safety issues relating to the use of these in the field. There is little information about ASFV antigens that can induce a protective immune response against challenge. We carried out a large screen of 30% of ASFV antigens by delivering individual genes in different pools to pigs by DNA immunization prime and recombinant

Generation and Production of Modified Vaccinia Virus Ankara (MVA) as a Vaccine Vector.

PubMed

Pavot, Vincent; Sebastian, Sarah; Turner, Alison V; Matthews, Jake; Gilbert, Sarah C

2017-01-01

The smallpox vaccine based on the vaccinia virus was successfully used to eradicate smallpox, but although very effective, it was a very reactogenic vaccine and responsible for the deaths of one to two people per million vaccinated. Modified Vaccinia virus Ankara (MVA) is an attenuated derivative, also used in the smallpox eradication campaign and now being developed as a recombinant viral vector to produce vaccines against infectious diseases and cancer. MVA can encode one or more foreign antigens and thus can function as a multivalent vaccine. The vector can be used at biosafety level 1, has intrinsic adjuvant properties, and induces humoral and cellular immune responses. Many clinical trials of these new vaccines have been conducted, and the safety of MVA is now well documented. Immunogenicity is influenced by the dose and vaccination regimen, and information on the efficacy of MVA-vectored vaccines is now beginning to accumulate. In this chapter, we provide protocols for generation, isolation, amplification, and purification of recombinant MVA for preclinical and clinical evaluation.

Cooperative vaccinia infection demonstrated at the single-cell level using FluidFM.

PubMed

Stiefel, Philipp; Schmidt, Florian I; Dörig, Pablo; Behr, Pascal; Zambelli, Tomaso; Vorholt, Julia A; Mercer, Jason

2012-08-08

The mechanisms used by viruses to enter and replicate within host cells are subjects of intense investigation. These studies are ultimately aimed at development of new drugs that interfere with these processes. Virus entry and infection are generally monitored by dispensing bulk virus suspensions on layers of cells without accounting for the fate of each virion. Here, we take advantage of the recently developed FluidFM to deposit single vaccinia virions onto individual cells in a controlled manner. While the majority of virions were blocked prior to early gene expression, infection of individual cells increased in a nondeterministic fashion with respect to the number of viruses placed. Microscopic analyses of several stages of the virus lifecycle indicated that this was the result of cooperativity between virions during early stages of infection. These findings highlight the importance of performing controlled virus infection experiments at the single cell level.

Ebola virus host cell entry.

PubMed

Sakurai, Yasuteru

2015-01-01

Ebola virus is an enveloped virus with filamentous structure and causes a severe hemorrhagic fever in human and nonhuman primates. Host cell entry is the first essential step in the viral life cycle, which has been extensively studied as one of the therapeutic targets. A virus factor of cell entry is a surface glycoprotein (GP), which is an only essential viral protein in the step, as well as the unique particle structure. The virus also interacts with a lot of host factors to successfully enter host cells. Ebola virus at first binds to cell surface proteins and internalizes into cells, followed by trafficking through endosomal vesicles to intracellular acidic compartments. There, host proteases process GPs, which can interact with an intracellular receptor. Then, under an appropriate circumstance, viral and endosomal membranes are fused, which is enhanced by major structural changes of GPs, to complete host cell entry. Recently the basic research of Ebola virus infection mechanism has markedly progressed, largely contributed by identification of host factors and detailed structural analyses of GPs. This article highlights the mechanism of Ebola virus host cell entry, including recent findings.

Vaccinia Virus Mutations in the L4R Gene Encoding a Virion Structural Protein Produce Abnormal Mature Particles Lacking a Nucleocapsid

PubMed Central

Moussatche, Nissin; Condit, Richard C.

2014-01-01

ABSTRACT Electron micrographs from the 1960s revealed the presence of an S-shaped tubular structure in the center of the vaccinia virion core. Recently, we showed that packaging of virus transcription enzymes is necessary for the formation of the tubular structure, suggesting that the structure is equivalent to a nucleocapsid. Based on this study and on what is known about nucleocapsids of other viruses, we hypothesized that in addition to transcription enzymes, the tubular structure also contains the viral DNA and a structural protein as a scaffold. The vaccinia virion structural protein L4 stands out as the best candidate for the role of a nucleocapsid structural protein because it is abundant, it is localized in the center of the virion core, and it binds DNA. In order to gain more insight into the structure and relevance of the nucleocapsid, we analyzed thermosensitive and inducible mutants in the L4R gene. Using a cryo-fixation method for electron microscopy (high-pressure freezing followed by freeze-substitution) to preserve labile structures like the nucleocapsid, we were able to demonstrate that in the absence of functional L4, mature particles with defective internal structures are produced under nonpermissive conditions. These particles do not contain a nucleocapsid. In addition, the core wall of these virions is abnormal. This suggests that the nucleocapsid interacts with the core wall and that the nucleocapsid structure might be more complex than originally assumed. IMPORTANCE The vaccinia virus nucleocapsid has been neglected since the 1960s due to a lack of electron microscopy techniques to preserve this labile structure. With the advent of cryo-fixation techniques, like high-pressure freezing/freeze-substitution, we are now able to consistently preserve and visualize the nucleocapsid. Because vaccinia virus early transcription is coupled to the viral core structure, detailing the structure of the nucleocapsid is indispensable for determining the

Vaccination with a codon-optimized A27L-containing plasmid decreases virus replication and dissemination after vaccinia virus challenge.

PubMed

Martínez, Osmarie; Bravo Cruz, Ariana; Santos, Saritza; Ramírez, Maite; Miranda, Eric; Shisler, Joanna; Otero, Miguel

2017-10-20

Smallpox is a disease caused by Variola virus (VARV). Although eradicated by WHO in 1980, the threat of using VARV on a bioterror attack has increased. The current smallpox vaccine ACAM2000, which consists of live vaccinia virus (VACV), causes complications in individuals with a compromised immune system or with previously reported skin diseases. Thus, a safer and efficacious vaccine needs to be developed. Previously, we reported that our virus-free DNA vaccine formulation, a pVAX1 plasmid encoding codon-optimized VACV A27L gene (pA27LOPT) with and without Imiquimod adjuvant, stimulates A27L-specific production of IFN-γ and increases humoral immunity 7days post-vaccination. Here, we investigated the immune response of our novel vaccine by measuring the frequency of splenocytes producing IFN-γ by ELISPOT, the TH1 and TH2 cytokine profiles, and humoral immune responses two weeks post-vaccination, when animals were challenged with VACV. In all assays, the A27-based DNA vaccine conferred protective immune responses. Specifically, two weeks after vaccination, mice were challenged intranasally with vaccinia virus, and viral titers in mouse lungs and ovaries were significantly lower in groups immunized with pA27LOPT and pA27LOPT+Imiquimod. These results demonstrate that our vaccine formulation decreases viral replication and dissemination in a virus-free DNA vaccine platform, and provides an alternative towards a safer an efficacious vaccine. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Long-lasting stability of vaccinia virus (orthopoxvirus) in food and environmental samples.

PubMed

Essbauer, S; Meyer, H; Porsch-Ozcürümez, M; Pfeffer, M

2007-01-01

Poxviruses are known to remain infectious in the scabs of patients for months to years. The aim of this study was to investigate viral stability in storm water, food or gauze spiked with vaccinia virus strain Munich 1 (VACV M1). Storm water, storm water supplemented with either fetal calf serum (FCS) or potting soil was stored at two different temperatures (refrigerator, room temperature; 4 degrees C/25 degrees C). In addition, we analysed the viability of VACV M1 on the surface of bread, salad, sausages and gauze bandages stored at 4 degrees C. Samples were titrated in MA 104 cells and the presence of viral DNA was demonstrated by orthopoxvirus-specific PCRs. After 2 weeks, reisolation of VACV M1 from all kinds of food, bandage and water samples except for storm water supplemented with potting soil was possible. Viral DNA was detected in almost all samples by PCR. Prolonged experiments with VACV M1-spiked storm water and storm water supplemented with FCS revealed that samples kept at 4.5 degrees C are infectious for up to 166 days. Our data demonstrate that VACV M1 has a longlasting stability in water and food. The results obtained during this study should be taken into account for risk assessment calculations for poxvirus transmission. Implying that variola virus and vaccinia virus behave in a similar way, our data call for sophisticated countermeasures in cases of a variola release in biological warfare.

The generation of CD8+ T-cell population specific for vaccinia virus epitope involved in the antiviral protection against ectromelia virus challenge.

PubMed

Gierynska, Malgorzata; Szulc-Dabrowska, Lidia; Dzieciatkowski, Tomasz; Golke, Anna; Schollenberger, Ada

2015-12-01

Eradication of smallpox has led to cessation of vaccination programs. This has rendered the human population increasingly susceptible not only to variola virus infection but also to infections with other representatives of Poxviridae family that cause zoonotic variola-like diseases. Thus, new approaches for designing improved vaccine against smallpox are required. Discovering that orthopoxviruses, e.g. variola virus, vaccinia virus, ectromelia virus, share common immunodominant antigen, may result in the development of such a vaccine. In our study, the generation of antigen-specific CD8(+) T cells in mice during the acute and memory phase of the immune response was induced using the vaccinia virus immunodominant TSYKFESV epitope and CpG oligodeoxynucleotides as adjuvants. The role of the generated TSYKFESV-specific CD8(+) T cells was evaluated in mice during ectromelia virus infection using systemic and mucosal model. Moreover, the involvement of dendritic cells subsets in the adaptive immune response stimulation was assessed. Our results indicate that the TSYKFESV epitope/TLR9 agonist approach, delivered systemically or mucosally, generated strong CD8(+) T-cell response when measured 10 days after immunization. Furthermore, the TSYKFESV-specific cell population remained functionally active 2 months post-immunization, and gave cross-protection in virally challenged mice, even though the numbers of detectable antigen-specific T cells decreased. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Recombinant modified vaccinia virus Ankara-based malaria vaccines.

PubMed

Sebastian, Sarah; Gilbert, Sarah C

2016-01-01

A safe and effective malaria vaccine is a crucial part of the roadmap to malaria elimination/eradication by the year 2050. Viral-vectored vaccines based on adenoviruses and modified vaccinia virus Ankara (MVA) expressing malaria immunogens are currently being used in heterologous prime-boost regimes in clinical trials for induction of strong antigen-specific T-cell responses and high-titer antibodies. Recombinant MVA is a safe and well-tolerated attenuated vector that has consistently shown significant boosting potential. Advances have been made in large-scale MVA manufacture as high-yield producer cell lines and high-throughput purification processes have recently been developed. This review describes the use of MVA as malaria vaccine vector in both preclinical and clinical studies in the past 5 years.

Novel Nonreplicating Vaccinia Virus Vector Enhances Expression of Heterologous Genes and Suppresses Synthesis of Endogenous Viral Proteins.

PubMed

Wyatt, Linda S; Xiao, Wei; Americo, Jeffrey L; Earl, Patricia L; Moss, Bernard

2017-06-06

Viruses are used as expression vectors for protein synthesis, immunology research, vaccines, and therapeutics. Advantages of poxvirus vectors include the accommodation of large amounts of heterologous DNA, the presence of a cytoplasmic site of transcription, and high expression levels. On the other hand, competition of approximately 200 viral genes with the target gene for expression and immune recognition may be disadvantageous. We describe a vaccinia virus (VACV) vector that uses an early promoter to express the bacteriophage T7 RNA polymerase; has the A23R intermediate transcription factor gene deleted, thereby restricting virus replication to complementing cells; and has a heterologous gene regulated by a T7 promoter. In noncomplementing cells, viral early gene expression and DNA replication occurred normally but synthesis of intermediate and late proteins was prevented. Nevertheless, the progeny viral DNA provided templates for abundant expression of heterologous genes regulated by a T7 promoter. Selective expression of the Escherichia coli lac repressor gene from an intermediate promoter reduced transcription of the heterologous gene specifically in complementing cells, where large amounts might adversely impact VACV replication. Expression of heterologous proteins mediated by the A23R deletion vector equaled that of a replicating VACV, was higher than that of a nonreplicating modified vaccinia virus Ankara (MVA) vector used for candidate vaccines in vitro and in vivo , and was similarly immunogenic in mice. Unlike the MVA vector, the A23R deletion vector still expresses numerous early genes that can restrict immunogenicity as demonstrated here by the failure of the prototype vector to induce interferon alpha. By deleting immunomodulatory genes, we anticipate further improvements in the system. IMPORTANCE Vaccines provide an efficient and effective way of preventing infectious diseases. Nevertheless, new and better vaccines are needed. Vaccinia virus, which

Vaccinia Virus Encodes a Novel Inhibitor of Apoptosis That Associates with the Apoptosome

PubMed Central

Ryerson, Melissa R.; Richards, Monique M.; Hawkins, Christine J.

2017-01-01

ABSTRACT Apoptosis is an important antiviral host defense mechanism. Here we report the identification of a novel apoptosis inhibitor encoded by the vaccinia virus (VACV) M1L gene. M1L is absent in the attenuated modified vaccinia virus Ankara (MVA) strain of VACV, a strain that stimulates apoptosis in several types of immune cells. M1 expression increased the viability of MVA-infected THP-1 and Jurkat cells and reduced several biochemical hallmarks of apoptosis, such as PARP-1 and procaspase-3 cleavage. Furthermore, ectopic M1L expression decreased staurosporine-induced (intrinsic) apoptosis in HeLa cells. We then identified the molecular basis for M1 inhibitory function. M1 allowed mitochondrial depolarization but blocked procaspase-9 processing, suggesting that M1 targeted the apoptosome. In support of this model, we found that M1 promoted survival in Saccharomyces cerevisiae overexpressing human Apaf-1 and procaspase-9, critical components of the apoptosome, or overexpressing only conformationally active caspase-9. In mammalian cells, M1 coimmunoprecipitated with Apaf-1–procaspase-9 complexes. The current model is that M1 associates with and allows the formation of the apoptosome but prevents apoptotic functions of the apoptosome. The M1 protein features 14 predicted ankyrin (ANK) repeat domains, and M1 is the first ANK-containing protein reported to use this inhibitory strategy. Since ANK-containing proteins are encoded by many large DNA viruses and found in all domains of life, studies of M1 may lead to a better understanding of the roles of ANK proteins in virus-host interactions. IMPORTANCE Apoptosis selectively eliminates dangerous cells such as virus-infected cells. Poxviruses express apoptosis antagonists to neutralize this antiviral host defense. The vaccinia virus (VACV) M1 ankyrin (ANK) protein, a protein with no previously ascribed function, inhibits apoptosis. M1 interacts with the apoptosome and prevents procaspase-9 processing as well as

SARS-CoV spike protein-expressing recombinant vaccinia virus efficiently induces neutralizing antibodies in rabbits pre-immunized with vaccinia virus.

PubMed

Kitabatake, Masahiro; Inoue, Shingo; Yasui, Fumihiko; Yokochi, Shoji; Arai, Masaaki; Morita, Kouichi; Shida, Hisatoshi; Kidokoro, Minoru; Murai, Fukashi; Le, Mai Quynh; Mizuno, Kyosuke; Matsushima, Kouji; Kohara, Michinori

2007-01-08

A vaccine for severe acute respiratory syndrome (SARS) is being intensively pursued against its re-emergence. We generated a SARS coronavirus (SARS-CoV) spike protein-expressing recombinant vaccinia virus (RVV-S) using highly attenuated strain LC16m8. Intradermal administration of RVV-S into rabbits induced neutralizing (NT) antibodies against SARS-CoV 1 week after administration and the NT titer reached 1:1000 after boost immunization with RVV-S. Significantly, NT antibodies against SARS-CoV were induced by administration of RVV-S to rabbits that had been pre-immunized with LC16m8. RVV-S can induce NT antibodies against SARS-CoV despite the presence of NT antibodies against VV. These results suggest that RVV-S may be a powerful SARS vaccine, including in patients previously immunized with the smallpox vaccine.

Enteric Immunization of Mice Against Influenza with Recombinant Vaccinia

NASA Astrophysics Data System (ADS)

Meitin, Catherine A.; Bender, Bradley S.; Small, Parker A., Jr.

1994-11-01

Intrajejunal administration to mice of a recombinant vaccinia virus containing the influenza virus hemagglutinin gene induced IgA antibody in nasal, gut, and vaginal secretions. It also induced IgG antibody in serum and cell-mediated immunity. The immunization provided significant protection against an influenza virus challenge. This work suggests that enteric-coated recombinant vaccinia could be an orally administered, inexpensive, multivalent, temperature-stable, safe, and effective vaccine for children that could be particularly useful in developing nations, where multiple injections are not easily administered. Oral administration of vaccines should also reduce children's fear of shots at the doctor's office.

The neutralizing antibody response to the vaccinia virus A28 protein is specifically enhanced by its association with the H2 protein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shinoda, Kaori; Wyatt, Linda S.; Moss, Bernard, E-mail: bmoss@niaid.nih.go

2010-09-15

The vaccinia virus (VACV) entry-fusion complex (EFC) is composed of at least nine membrane proteins. Immunization of mice with individual EFC genes induced corresponding protein-binding antibody but failed to protect against VACV intranasal challenge and only DNA encoding A28 elicited low neutralizing antibody. Because the A28 and H2 proteins interact, we determined the effect of immunizing with both genes simultaneously. This procedure greatly enhanced the amount of antibody that bound intact virions, neutralized infectivity, and provided partial protection against respiratory challenge. Neither injection of A28 and H2 plasmids at different sites or mixing A28 and H2 sera enhanced neutralizing antibody.more » The neutralizing antibody could be completely removed by binding to the A28 protein alone and the epitope was located in the C-terminal segment. These data suggest that the interaction of H2 with A28 stabilizes the immunogenic form of A28, mimicking an exposed region of the entry-fusion complex on infectious virions.« less

Pre-clinical efficacy and safety of experimental vaccines based on non-replicating vaccinia vectors against yellow fever.

PubMed

Schäfer, Birgit; Holzer, Georg W; Joachimsthaler, Alexandra; Coulibaly, Sogue; Schwendinger, Michael; Crowe, Brian A; Kreil, Thomas R; Barrett, P Noel; Falkner, Falko G

2011-01-01

Currently existing yellow fever (YF) vaccines are based on the live attenuated yellow fever virus 17D strain (YFV-17D). Although, a good safety profile was historically attributed to the 17D vaccine, serious adverse events have been reported, making the development of a safer, more modern vaccine desirable. A gene encoding the precursor of the membrane and envelope (prME) protein of the YFV-17D strain was inserted into the non-replicating modified vaccinia virus Ankara and into the D4R-defective vaccinia virus. Candidate vaccines based on the recombinant vaccinia viruses were assessed for immunogenicity and protection in a mouse model and compared to the commercial YFV-17D vaccine. The recombinant live vaccines induced γ-interferon-secreting CD4- and functionally active CD8-T cells, and conferred full protection against lethal challenge already after a single low immunization dose of 10(5) TCID(50). Surprisingly, pre-existing immunity against wild-type vaccinia virus did not negatively influence protection. Unlike the classical 17D vaccine, the vaccinia virus-based vaccines did not cause mortality following intracerebral administration in mice, demonstrating better safety profiles. The non-replicating recombinant YF candidate live vaccines induced a broad immune response after single dose administration, were effective even in the presence of a pre-existing immunity against vaccinia virus and demonstrated an excellent safety profile in mice.

The attenuated NYCBH vaccinia virus deleted for the immune evasion gene, E3L, completely protects mice against heterologous challenge with ectromelia virus.

PubMed

Denzler, Karen L; Schriewer, Jill; Parker, Scott; Werner, Chas; Hartzler, Hollyce; Hembrador, Ed; Huynh, Trung; Holechek, Susan; Buller, R M; Jacobs, Bertram L

2011-12-06

The New York City Board of Health (NYCBH) vaccinia virus (VACV) vaccine strain was deleted for the immune evasion gene, E3L, and tested for its pathogenicity and ability to protect mice from heterologous challenge with ectromelia virus (ECTV). NYCBHΔE3L was found to be highly attenuated for pathogenicity in a newborn mouse model and showed a similar attenuated phenotype as the NYVAC strain of vaccinia virus. Scarification with one or two doses of the attenuated NYCBHΔE3L was able to protect mice equally as well as NYCBH from death, weight loss, and viral spread to visceral organs. A single dose of NYCBHΔE3L resulted in low poxvirus-specific antibodies, and a second dose increased levels of poxvirus-specific antibodies to a level similar to that seen in animals vaccinated with a single dose of NYCBH. However, similar neutralizing antibody titers were observed following one or two doses of NYCBHΔE3L or NYCBH. Thus, NYCBHΔE3L shows potential as a candidate for a safer human smallpox vaccine since it protects mice from challenge with a heterologous poxvirus. Copyright © 2011 Elsevier Ltd. All rights reserved.

A heterologous prime-boosting strategy with replicating Vaccinia virus vectors and plant-produced HIV-1 Gag/dgp41 virus-like particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meador, Lydia R.

Showing modest efficacy, the RV144 HIV-1 vaccine clinical trial utilized a non-replicating canarypox viral vector and a soluble gp120 protein boost. Here we built upon the RV144 strategy by developing a novel combination of a replicating, but highly-attenuated Vaccinia virus vector, NYVAC-KC, and plant-produced HIV-1 virus-like particles (VLPs). Both components contained the full-length Gag and a membrane anchored truncated gp41 presenting the membrane proximal external region with its conserved broadly neutralizing epitopes in the pre-fusion conformation. We tested different prime/boost combinations of these components in mice and showed that the group primed with NYVAC-KC and boosted with both the viralmore » vectors and plant-produced VLPs have the most robust Gag-specific CD8 T cell responses, at 12.7% of CD8 T cells expressing IFN-γ in response to stimulation with five Gag epitopes. The same immunization group elicited the best systemic and mucosal antibody responses to Gag and dgp41 with a bias towards IgG1. - Highlights: • We devised a prime/boost anti HIV-1 vaccination strategy modeled after RV144. • We used plant-derived virus-like particles (VLPs) consisting of Gag and dgp41. • We used attenuated, replicating vaccinia virus vectors expressing the same antigens. • The immunogens elicited strong cellular and humoral immune responses.« less

The 3'-to-5' exonuclease activity of vaccinia virus DNA polymerase is essential and plays a role in promoting virus genetic recombination.

PubMed

Gammon, Don B; Evans, David H

2009-05-01

Poxviruses are subjected to extraordinarily high levels of genetic recombination during infection, although the enzymes catalyzing these reactions have never been identified. However, it is clear that virus-encoded DNA polymerases play some unknown yet critical role in virus recombination. Using a novel, antiviral-drug-based strategy to dissect recombination and replication reactions, we now show that the 3'-to-5' proofreading exonuclease activity of the viral DNA polymerase plays a key role in promoting recombination reactions. Linear DNA substrates were prepared containing the dCMP analog cidofovir (CDV) incorporated into the 3' ends of the molecules. The drug blocked the formation of concatemeric recombinant molecules in vitro in a process that was catalyzed by the proofreading activity of vaccinia virus DNA polymerase. Recombinant formation was also blocked when CDV-containing recombination substrates were transfected into cells infected with wild-type vaccinia virus. These inhibitory effects could be overcome if CDV-containing substrates were transfected into cells infected with CDV-resistant (CDV(r)) viruses, but only when resistance was linked to an A314T substitution mutation mapping within the 3'-to-5' exonuclease domain of the viral polymerase. Viruses encoding a CDV(r) mutation in the polymerase domain still exhibited a CDV-induced recombination deficiency. The A314T substitution also enhanced the enzyme's capacity to excise CDV molecules from the 3' ends of duplex DNA and to recombine these DNAs in vitro, as judged from experiments using purified mutant DNA polymerase. The 3'-to-5' exonuclease activity appears to be an essential virus function, and our results suggest that this might be because poxviruses use it to promote genetic exchange.

A kinesin-1 binding motif in vaccinia virus that is widespread throughout the human genome

PubMed Central

Dodding, Mark P; Mitter, Richard; Humphries, Ashley C; Way, Michael

2011-01-01

Transport of cargoes by kinesin-1 is essential for many cellular processes. Nevertheless, the number of proteins known to recruit kinesin-1 via its cargo binding light chain (KLC) is still quite small. We also know relatively little about the molecular features that define kinesin-1 binding. We now show that a bipartite tryptophan-based kinesin-1 binding motif, originally identified in Calsyntenin is present in A36, a vaccinia integral membrane protein. This bipartite motif in A36 is required for kinesin-1-dependent transport of the virus to the cell periphery. Bioinformatic analysis reveals that related bipartite tryptophan-based motifs are present in over 450 human proteins. Using vaccinia as a surrogate cargo, we show that regions of proteins containing this motif can function to recruit KLC and promote virus transport in the absence of A36. These proteins interact with the kinesin light chain outside the context of infection and have distinct preferences for KLC1 and KLC2. Our observations demonstrate that KLC binding can be conferred by a common set of features that are found in a wide range of proteins associated with diverse cellular functions and human diseases. PMID:21915095

Pre-Clinical Efficacy and Safety of Experimental Vaccines Based on Non-Replicating Vaccinia Vectors against Yellow Fever

PubMed Central

Schäfer, Birgit; Holzer, Georg W.; Joachimsthaler, Alexandra; Coulibaly, Sogue; Schwendinger, Michael; Crowe, Brian A.; Kreil, Thomas R.; Barrett, P. Noel; Falkner, Falko G.

2011-01-01

Background Currently existing yellow fever (YF) vaccines are based on the live attenuated yellow fever virus 17D strain (YFV-17D). Although, a good safety profile was historically attributed to the 17D vaccine, serious adverse events have been reported, making the development of a safer, more modern vaccine desirable. Methodology/Principal Findings A gene encoding the precursor of the membrane and envelope (prME) protein of the YFV-17D strain was inserted into the non-replicating modified vaccinia virus Ankara and into the D4R-defective vaccinia virus. Candidate vaccines based on the recombinant vaccinia viruses were assessed for immunogenicity and protection in a mouse model and compared to the commercial YFV-17D vaccine. The recombinant live vaccines induced γ-interferon-secreting CD4- and functionally active CD8-T cells, and conferred full protection against lethal challenge already after a single low immunization dose of 105 TCID50. Surprisingly, pre-existing immunity against wild-type vaccinia virus did not negatively influence protection. Unlike the classical 17D vaccine, the vaccinia virus-based vaccines did not cause mortality following intracerebral administration in mice, demonstrating better safety profiles. Conclusions/Significance The non-replicating recombinant YF candidate live vaccines induced a broad immune response after single dose administration, were effective even in the presence of a pre-existing immunity against vaccinia virus and demonstrated an excellent safety profile in mice. PMID:21931732

Functional Analysis of Vaccinia Virus B5R Protein: Essential Role in Virus Envelopment Is Independent of a Large Portion of the Extracellular Domain

PubMed Central

Herrera, Elizabeth; del Mar Lorenzo, María; Blasco, Rafael; Isaacs, Stuart N.

1998-01-01

Vaccinia virus has two forms of infectious virions: the intracellular mature virus and the extracellular enveloped virus (EEV). EEV is critical for cell-to-cell and long-range spread of the virus. The B5R open reading frame (ORF) encodes a membrane protein that is essential for EEV formation. Deletion of the B5R ORF results in a dramatic reduction of EEV, and as a consequence, the virus produces small plaques in vitro and is highly attenuated in vivo. The extracellular portion of B5R is composed mainly of four domains that are similar to the short consensus repeats (SCRs) present in complement regulatory proteins. To determine the contribution of these putative SCR domains to EEV formation, we constructed recombinant vaccinia viruses that replaced the wild-type B5R gene with a mutated gene encoding a B5R protein lacking the SCRs. The resulting recombinant viruses produced large plaques, indicating efficient cell-to-cell spread in vitro, and gradient centrifugation of supernatants from infected cells confirmed that EEV was formed. In contrast, phalloidin staining of infected cells showed that the virus lacking the SCR domains was deficient in the induction of thick actin bundles. Thus, the highly conserved SCR domains present in the extracellular portion of the B5R protein are dispensable for EEV formation. This indicates that the B5R protein is a key viral protein with multiple functions in the process of virus envelopment and release. In addition, given the similarity of the extracellular domain to complement control proteins, the B5R protein may be involved in viral evasion from host immune responses. PMID:9420227

Protective effect of surfactant protein d in pulmonary vaccinia virus infection: implication of A27 viral protein.

PubMed

Perino, Julien; Thielens, Nicole M; Crouch, Erika; Spehner, Danièle; Crance, Jean-Marc; Favier, Anne-Laure

2013-03-21

Vaccinia virus (VACV) was used as a surrogate of variola virus (VARV) (genus Orthopoxvirus), the causative agent of smallpox, to study Orthopoxvirus infection. VARV is principally transmitted between humans by aerosol droplets. Once inhaled, VARV first infects the respiratory tract where it could encounter surfactant components, such as soluble pattern recognition receptors. Surfactant protein D (SP-D), constitutively present in the lining fluids of the respiratory tract, plays important roles in innate host defense against virus infection. We investigated the role of SP-D in VACV infection and studied the A27 viral protein involvement in the interaction with SP-D. Interaction between SP-D and VACV caused viral inhibition in a lung cell model. Interaction of SP-D with VACV was mediated by the A27 viral protein. Binding required Ca2+ and interactions were blocked in the presence of excess of SP-D saccharide ligands. A27, which lacks glycosylation, directly interacted with SP-D. The interaction between SP-D and the viral particle was also observed using electron microscopy. Infection of mice lacking SP-D (SP-D-/-) resulted in increased mortality compared to SP-D+/+ mice. Altogether, our data show that SP-D participates in host defense against the vaccinia virus infection and that the interaction occurs with the viral surface protein A27.

Species Specificity of Vaccinia Virus Complement Control Protein for the Bovine Classical Pathway Is Governed Primarily by Direct Interaction of Its Acidic Residues with Factor I

PubMed Central

Kumar, Jitendra; Yadav, Viveka Nand; Phulera, Swastik; Kamble, Ashish; Gautam, Avneesh Kumar; Panwar, Hemendra Singh

2017-01-01

ABSTRACT Poxviruses display species tropism—variola virus is a human-specific virus, while vaccinia virus causes repeated outbreaks in dairy cattle. Consistent with this, variola virus complement regulator SPICE (smallpox inhibitor of complement enzymes) exhibits selectivity in inhibiting the human alternative complement pathway and vaccinia virus complement regulator VCP (vaccinia virus complement control protein) displays selectivity in inhibiting the bovine alternative complement pathway. In the present study, we examined the species specificity of VCP and SPICE for the classical pathway (CP). We observed that VCP is ∼43-fold superior to SPICE in inhibiting bovine CP. Further, functional assays revealed that increased inhibitory activity of VCP for bovine CP is solely due to its enhanced cofactor activity, with no effect on decay of bovine CP C3-convertase. To probe the structural basis of this specificity, we utilized single- and multi-amino-acid substitution mutants wherein 1 or more of the 11 variant VCP residues were substituted in the SPICE template. Examination of these mutants for their ability to inhibit bovine CP revealed that E108, E120, and E144 are primarily responsible for imparting the specificity and contribute to the enhanced cofactor activity of VCP. Binding and functional assays suggested that these residues interact with bovine factor I but not with bovine C4(H2O) (a moiety conformationally similar to C4b). Mapping of these residues onto the modeled structure of bovine C4b-VCP-bovine factor I supported the mutagenesis data. Taken together, our data help explain why the vaccine strain of vaccinia virus was able to gain a foothold in domesticated animals. IMPORTANCE Vaccinia virus was used for smallpox vaccination. The vaccine-derived virus is now circulating and causing outbreaks in dairy cattle in India and Brazil. However, the reason for this tropism is unknown. It is well recognized that the virus is susceptible to neutralization by the

Effects of pre-existing orthopoxvirus-specific immunity on the performance of Modified Vaccinia virus Ankara-based influenza vaccines.

PubMed

Altenburg, Arwen F; van Trierum, Stella E; de Bruin, Erwin; de Meulder, Dennis; van de Sandt, Carolien E; van der Klis, Fiona R M; Fouchier, Ron A M; Koopmans, Marion P G; Rimmelzwaan, Guus F; de Vries, Rory D

2018-04-24

The replication-deficient orthopoxvirus modified vaccinia virus Ankara (MVA) is a promising vaccine vector against various pathogens and has an excellent safety record. However, pre-existing vector-specific immunity is frequently suggested to be a drawback of MVA-based vaccines. To address this issue, mice were vaccinated with MVA-based influenza vaccines in the presence or absence of orthopoxvirus-specific immunity. Importantly, protective efficacy of an MVA-based influenza vaccine against a homologous challenge was not impaired in the presence of orthopoxvirus-specific pre-existing immunity. Nonetheless, orthopoxvirus-specific pre-existing immunity reduced the induction of antigen-specific antibodies under specific conditions and completely prevented induction of antigen-specific T cell responses by rMVA-based vaccination. Notably, antibodies induced by vaccinia virus vaccination, both in mice and humans, were not capable of neutralizing MVA. Thus, when using rMVA-based vaccines it is important to consider the main correlate of protection induced by the vaccine, the vaccine dose and the orthopoxvirus immune status of vaccine recipients.

Immunogenicity of recombinant vaccinia virus vaccines co-expressing GP3/GP5 of European PRRSV and Cap protein of PCV2 in pigs.

PubMed

Han, Jicheng; Ma, Haibin; Cao, Liang; Jing, Jie; Xiao, Pengpeng; Sun, Wenchao; Xie, Changzhan; Wen, Shubo; Li, Yiquan; Tian, Mingyao; Lu, Huijun; Jin, Ningyi

2018-02-01

Porcine reproductive and respiratory syndrome (PRRS) is almost always caused by the North American strain of PRRS virus (PRRSV) in China; the European genotype of PRRSV has emerged in China. The mixed infection of PRRSV and Porcine circovirus type 2 virus (PCV2) are always found in pigs and PRRSV-augmented PCV2 replication and serious clinical symptoms. Current vaccines cannot protect mixed European PRRSV and PCV2 infections. Therefore, the development of a safe and effective new vaccine to prevent and control the mixed infection of European PRRSV and PCV2 is both urgent and necessary. In this study, we developed a recombinant vaccinia vaccine co-expressing the GP3 and GP5 proteins of European PRRSV and the ORF2 protein of PCV2 and evaluated the immunogenicity and its protective effects and its inactivated vaccine in pigs. The recombinant vaccinia vaccine and its inactivated vaccine both elicited significant humoral and cellular immune responses with a higher level of specific antibody responses and T-lymphocyte proliferation than the control group. Furthermore, the pigs inoculated with the recombinant vaccinia vaccine were completely protected against challenge with 10 5 TCID 50 of European PRRSV strain LV. These data suggest that the recombinant vaccinia vaccine is a potential candidate vaccine against European PRRSV and PCV2.

Coinfection with recombinant vaccinia viruses expressing poliovirus P1 and P3 proteins results in polyprotein processing and formation of empty capsid structures.

PubMed

Ansardi, D C; Porter, D C; Morrow, C D

1991-04-01

The assembly process of poliovirus occurs via an ordered proteolytic processing of the capsid precursor protein, P1, by the virus-encoded proteinase 3CD. To further delineate this process, we have isolated a recombinant vaccinia virus which expresses, upon infection, the poliovirus P1 capsid precursor polyprotein with an authentic carboxy terminus. Coinfection of HeLa cells with the P1-expressing vaccinia virus and with a second recombinant vaccinia virus which expresses the poliovirus proteinase 3CD resulted in the correct processing of P1 to yield the three individual capsid proteins VP0, VP3, and VP1. When extracts from coinfected cells were fractionated on sucrose density gradients, the VP0, VP3, and VP1 capsid proteins were immunoprecipitated with type 1 poliovirus antisera from fractions corresponding to a sedimentation consistent for poliovirus 75S procapsids. Examination of these fractions by electron microscopy revealed structures which lacked electron-dense cores and which corresponded in size and shape to those expected for poliovirus empty capsids. We conclude that the expression of the two poliovirus proteins P1 and 3CD in coinfected cells is sufficient for the correct processing of the capsid precursor to VP0, VP3, and VP1 as well as for the assembly of poliovirus empty capsid-like structures.

Evidence for Protection against Chronic Hepatitis C Virus Infection in Chimpanzees by Immunization with Replicating Recombinant Vaccinia Virus▿

PubMed Central

Youn, Jin-Won; Hu, Yu-Wen; Tricoche, Nancy; Pfahler, Wolfram; Shata, Mohamed Tarek; Dreux, Marlene; Cosset, François-Loic; Folgori, Antonella; Lee, Dong-Hun; Brotman, Betsy; Prince, Alfred M.

2008-01-01

Given the failures of nonreplicating vaccines against chronic hepatitis C virus (HCV) infection, we hypothesized that a replicating viral vector may provide protective immunity. Four chimpanzees were immunized transdermally twice with recombinant vaccinia viruses (rVV) expressing HCV genes. After challenge with 24 50% chimpanzee infective doses of homologous HCV, the two control animals that had received only the parental VV developed chronic HCV infection. All four immunized animals resolved HCV infection. The difference in the rate of chronicity between the immunized and the control animals was close to statistical significance (P = 0.067). Immunized animals developed vigorous gamma interferon enzyme-linked immunospot responses and moderate proliferative responses. To investigate cross-genotype protection, the immunized recovered chimpanzees were challenged with a pool of six major HCV genotypes. During the acute phase after the multigenotype challenge, all animals had high-titer viremia in which genotype 4 dominated (87%), followed by genotype 5 (13%). However, after fluctuating low-level viremia, the viremia finally turned negative or persisted at very low levels. This study suggests the potential efficacy of replicating recombinant vaccinia virus-based immunization against chronic HCV infection. PMID:18753204

Recombinant modified vaccinia virus Ankara generating excess early double-stranded RNA transiently activates protein kinase R and triggers enhanced innate immune responses.

PubMed

Wolferstätter, Michael; Schweneker, Marc; Späth, Michaela; Lukassen, Susanne; Klingenberg, Marieken; Brinkmann, Kay; Wielert, Ursula; Lauterbach, Henning; Hochrein, Hubertus; Chaplin, Paul; Suter, Mark; Hausmann, Jürgen

2014-12-01

Double-stranded RNA (dsRNA) is an important molecular pattern associated with viral infection and is detected by various extra- and intracellular recognition molecules. Poxviruses have evolved to avoid producing dsRNA early in infection but generate significant amounts of dsRNA late in infection due to convergent transcription of late genes. Protein kinase R (PKR) is activated by dsRNA and triggers major cellular defenses against viral infection, including protein synthesis shutdown, apoptosis, and type I interferon (IFN-I) production. The poxviral E3 protein binds and sequesters viral dsRNA and is a major antagonist of the PKR pathway. We found that the highly replication-restricted modified vaccinia virus Ankara (MVA) engineered to produce excess amounts of dsRNA early in infection showed enhanced induction of IFN-β in murine and human cells in the presence of an intact E3L gene. IFN-β induction required a minimum overlap length of 300 bp between early complementary transcripts and was strongly PKR dependent. Excess early dsRNA produced by MVA activated PKR early but transiently in murine cells and induced enhanced systemic levels of IFN-α, IFN-γ, and other cytokines and chemokines in mice in a largely PKR-dependent manner. Replication-competent chorioallantois vaccinia virus Ankara (CVA) generating excess early dsRNA also enhanced IFN-I production and was apathogenic in mice even at very high doses but showed no in vitro host range defect. Thus, genetically adjuvanting MVA and CVA to generate excess early dsRNA is an effective method to enhance innate immune stimulation by orthopoxvirus vectors and to attenuate replicating vaccinia virus in vivo. Efficient cellular sensing of pathogen-specific components, including double-stranded RNA (dsRNA), is an important prerequisite of an effective antiviral immune response. The prototype poxvirus vaccinia virus (VACV) and its derivative modified vaccinia virus Ankara (MVA) produce dsRNA as a by-product of viral

Protein and modified vaccinia virus Ankara-based influenza virus nucleoprotein vaccines are differentially immunogenic in BALB/c mice.

PubMed

Altenburg, A F; Magnusson, S E; Bosman, F; Stertman, L; de Vries, R D; Rimmelzwaan, G F

2017-10-01

Because of the high variability of seasonal influenza viruses and the eminent threat of influenza viruses with pandemic potential, there is great interest in the development of vaccines that induce broadly protective immunity. Most probably, broadly protective influenza vaccines are based on conserved proteins, such as nucleoprotein (NP). NP is a vaccine target of interest as it has been shown to induce cross-reactive antibody and T cell responses. Here we tested and compared various NP-based vaccine preparations for their capacity to induce humoral and cellular immune responses to influenza virus NP. The immunogenicity of protein-based vaccine preparations with Matrix-M™ adjuvant as well as recombinant viral vaccine vector modified Vaccinia virus Ankara (MVA) expressing the influenza virus NP gene, with or without modifications that aim at optimization of CD8 + T cell responses, was addressed in BALB/c mice. Addition of Matrix-M™ adjuvant to NP wild-type protein-based vaccines significantly improved T cell responses. Furthermore, recombinant MVA expressing the influenza virus NP induced strong antibody and CD8 + T cell responses, which could not be improved further by modifications of NP to increase antigen processing and presentation. © 2017 British Society for Immunology.

Serologic and Molecular Evidence of Vaccinia Virus Circulation among Small Mammals from Different Biomes, Brazil

PubMed Central

Miranda, Júlia B.; Borges, Iara A.; Campos, Samantha P.S.; Vieira, Flávia N.; de Ázara, Tatiana M.F.; Marques, Fernanda A.; Costa, Galileu B.; Luis, Ana Paula M.F.; de Oliveira, Jaqueline S.; Ferreira, Paulo César P.; Bonjardim, Cláudio Antônio; da Silva, Silvio L.M.; Eiras, Álvaro E.; Abrahão, Jônatas S.; Kroon, Erna G.; Drumond, Betânia P.; Paglia, Adriano P.

2017-01-01

Vaccinia virus (VACV) is a zoonotic agent that causes a disease called bovine vaccinia, which is detected mainly in milking cattle and humans in close contact with these animals. Even though many aspects of VACV infection have been described, much is still unknown about its circulation in the environment and its natural hosts/reservoirs. To investigate the presence of Orthopoxvirus antibodies or VACV DNA, we captured small rodents and marsupials in 3 areas of Minas Gerais state, Brazil, and tested their samples in a laboratory. A total of 336 animals were tested; positivity ranged from 18.1% to 25.5% in the 3 studied regions located in different biomes, including the Atlantic Forest and the Cerrado. Analysis of nucleotide sequences indicated co-circulation of VACV groups I and II. Our findings reinforce the possible role played by rodents and marsupials in VACV maintenance and its transmission chain. PMID:28518030

Vaccinia virus Transmission through Experimentally Contaminated Milk Using a Murine Model

PubMed Central

Rehfeld, Izabelle Silva; Guedes, Maria Isabel Maldonado Coelho; Fraiha, Ana Luiza Soares; Costa, Aristóteles Gomes; Matos, Ana Carolina Diniz; Fiúza, Aparecida Tatiane Lino; Lobato, Zélia Inês Portela

2015-01-01

Bovine vaccinia (BV) is a zoonosis caused by Vaccinia virus (VACV), which affects dairy cattle and humans. Previous studies have detected the presence of viable virus particles in bovine milk samples naturally and experimentally contaminated with VACV. However, it is not known whether milk contaminated with VACV could be a route of viral transmission. However, anti-Orthopoxvirus antibodies were detected in humans from BV endemic areas, whom had no contact with affected cows, which suggest that other VACV transmission routes are possible, such as consumption of contaminated milk and dairy products. Therefore, it is important to study the possibility of VACV transmission by contaminated milk. This study aimed to examine VACV transmission, pathogenesis and shedding in mice orally inoculated with experimentally contaminated milk. Thirty mice were orally inoculated with milk containing 107 PFU/ml of VACV, and ten mice were orally inoculated with uncontaminated milk. Clinical examinations were performed for 30 consecutive days, and fecal samples and oral swabs (OSs) were collected every other day. Mice were euthanized on predetermined days, and tissue and blood samples were collected. Nested-PCR, plaque reduction neutralization test (PRNT), viral isolation, histopathology, and immunohistochemistry (IHC) methods were performed on the collected samples. No clinical changes were observed in the animals. Viral DNA was detected in feces, blood, OSs and tissues, at least in one of the times tested. The lungs displayed moderate to severe interstitial lymphohistiocytic infiltrates, and only the heart, tonsils, tongue, and stomach did not show immunostaining at the IHC analysis. Neutralizing antibodies were detected at the 20th and 30th days post infection in 50% of infected mice. The results revealed that VACV contaminated milk could be a route of viral transmission in mice experimentally infected, showing systemic distribution and shedding through feces and oral mucosa, albeit

Unintentional transfer of vaccinia virus associated with smallpox vaccines: ACAM2000(®) compared with Dryvax(®).

PubMed

Tack, Danielle M; Karem, Kevin L; Montgomery, Jay R; Collins, Limone; Bryant-Genevier, Marthe G; Tiernan, Rosemary; Cano, Maria; Lewis, Paige; Engler, Renata J M; Damon, Inger K; Reynolds, Mary G

2013-07-01

Routine vaccination against smallpox (variola) ceased in the US in 1976. However, in 2002 limited coverage for military personnel and some healthcare workers was reinstituted. In March 2008, ACAM2000® replaced Dryvax® as the vaccine used in the United States against smallpox. Unintentional transfer of vaccinia virus from a vaccination site by autoinoculation or contact transmission, can have significant public health implications. We summarize unintentional virus transfer AEs associated with ACAM2000® since March 2008 and compare with Dryvax®. We identified 309 reports for ACAM2000® with skin or ocular involvement, of which 93 were autoinoculation cases and 20 were contact transmission cases. The rate for reported cases of autoinoculation was 20.6 per 100,000 vaccinations and for contact transmission was 4.4 per 100,000 vaccinations. Eighteen contact transmission cases could be attributed to contact during a sporting activity (45%) or intimate contact (45%). Of the 113 unintentional transfer cases, 6 met the case definition for ocular vaccinia. The most common locations for all autoinoculation and contact cases were arm/elbow/shoulder (35/113; 31%) and face (24/113; 21%). Methods We reviewed 753 reports associated with smallpox in the Vaccine Adverse Event Reporting System and CDC Poxvirus consultation log, reported from March 2008 to August 2010. Reports were classified into categories based upon standard case definitions. Overall, unintentional transfer events for ACAM2000® and Dryvax® are similar. We recommend continued efforts to prevent transfer events and continuing education for healthcare providers focused on recognition of vaccinia lesions, proper sample collection, and laboratory testing to confirm diagnosis.

Safety and Immunogenicity of Modified Vaccinia Ankara-Bavarian Nordic Smallpox Vaccine in Vaccinia-Naive and Experienced Human Immunodeficiency Virus-Infected Individuals: An Open-Label, Controlled Clinical Phase II Trial.

PubMed

Overton, Edgar Turner; Stapleton, Jack; Frank, Ian; Hassler, Shawn; Goepfert, Paul A; Barker, David; Wagner, Eva; von Krempelhuber, Alfred; Virgin, Garth; Meyer, Thomas Peter; Müller, Jutta; Bädeker, Nicole; Grünert, Robert; Young, Philip; Rösch, Siegfried; Maclennan, Jane; Arndtz-Wiedemann, Nathaly; Chaplin, Paul

2015-04-01

Background.  First- and second-generation smallpox vaccines are contraindicated in individuals infected with human immunodeficiency virus (HIV). A new smallpox vaccine is needed to protect this population in the context of biodefense preparedness. The focus of this study was to compare the safety and immunogenicity of a replication-deficient, highly attenuated smallpox vaccine modified vaccinia Ankara (MVA) in HIV-infected and healthy subjects. Methods.  An open-label, controlled Phase II trial was conducted at 36 centers in the United States and Puerto Rico for HIV-infected and healthy subjects. Subjects received 2 doses of MVA administered 4 weeks apart. Safety was evaluated by assessment of adverse events, focused physical exams, electrocardiogram recordings, and safety laboratories. Immune responses were assessed using enzyme-linked immunosorbent assay (ELISA) and a plaque reduction neutralization test (PRNT). Results.  Five hundred seventy-nine subjects were vaccinated at least once and had data available for analysis. Rates of ELISA seropositivity were comparably high in vaccinia-naive healthy and HIV-infected subjects, whereas PRNT seropositivity rates were higher in healthy compared with HIV-infected subjects. Modified vaccinia Ankara was safe and well tolerated with no adverse impact on viral load or CD4 counts. There were no cases of myo-/pericarditis reported. Conclusions.  Modified vaccinia Ankara was safe and immunogenic in subjects infected with HIV and represents a promising smallpox vaccine candidate for use in immunocompromised populations.

Safety and Immunogenicity of Modified Vaccinia Ankara-Bavarian Nordic Smallpox Vaccine in Vaccinia-Naive and Experienced Human Immunodeficiency Virus-Infected Individuals: An Open-Label, Controlled Clinical Phase II Trial

PubMed Central

Overton, Edgar Turner; Stapleton, Jack; Frank, Ian; Hassler, Shawn; Goepfert, Paul A.; Barker, David; Wagner, Eva; von Krempelhuber, Alfred; Virgin, Garth; Meyer, Thomas Peter; Müller, Jutta; Bädeker, Nicole; Grünert, Robert; Young, Philip; Rösch, Siegfried; Maclennan, Jane; Arndtz-Wiedemann, Nathaly; Chaplin, Paul

2015-01-01

Background. First- and second-generation smallpox vaccines are contraindicated in individuals infected with human immunodeficiency virus (HIV). A new smallpox vaccine is needed to protect this population in the context of biodefense preparedness. The focus of this study was to compare the safety and immunogenicity of a replication-deficient, highly attenuated smallpox vaccine modified vaccinia Ankara (MVA) in HIV-infected and healthy subjects. Methods. An open-label, controlled Phase II trial was conducted at 36 centers in the United States and Puerto Rico for HIV-infected and healthy subjects. Subjects received 2 doses of MVA administered 4 weeks apart. Safety was evaluated by assessment of adverse events, focused physical exams, electrocardiogram recordings, and safety laboratories. Immune responses were assessed using enzyme-linked immunosorbent assay (ELISA) and a plaque reduction neutralization test (PRNT). Results. Five hundred seventy-nine subjects were vaccinated at least once and had data available for analysis. Rates of ELISA seropositivity were comparably high in vaccinia-naive healthy and HIV-infected subjects, whereas PRNT seropositivity rates were higher in healthy compared with HIV-infected subjects. Modified vaccinia Ankara was safe and well tolerated with no adverse impact on viral load or CD4 counts. There were no cases of myo-/pericarditis reported. Conclusions. Modified vaccinia Ankara was safe and immunogenic in subjects infected with HIV and represents a promising smallpox vaccine candidate for use in immunocompromised populations. PMID:26380340

Dogs and Opossums Positive for Vaccinia Virus during Outbreak Affecting Cattle and Humans, São Paulo State, Brazil.

PubMed

Peres, Marina G; Barros, Claudenice B; Appolinário, Camila M; Antunes, João M A P; Mioni, Mateus S R; Bacchiega, Thais S; Allendorf, Susan D; Vicente, Acácia F; Fonseca, Clóvis R; Megid, Jane

2016-02-01

During a vaccinia virus (VACV) outbreak in São Paulo State, Brazil, blood samples were collected from cows, humans, other domestic animals, and wild mammals. Samples from 3 dogs and 3 opossums were positive for VACV by PCR. Results of gene sequencing yielded major questions regarding other mammalian species acting as reservoirs of VACV.

Host range, growth property, and virulence of the smallpox vaccine: Vaccinia virus Tian Tan strain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang Qing; Yang Lin; Zhu Weijun

2005-05-10

Vaccinia Tian Tan (VTT) was used as a vaccine against smallpox in China for millions of people before 1980, yet the biological characteristics of the virus remain unclear. We have characterized VTT with respect to its host cell range, growth properties in vitro, and virulence in vivo. We found that 11 of the 12 mammalian cell lines studied are permissive to VTT infection whereas one, CHO-K1, is non-permissive. Using electron microscopy and sequence analysis, we found that the restriction of VTT replication in CHO-K1 is at a step before viral maturation probably due to the loss of the V025 gene.more » Moreover, VTT is significantly less virulent than vaccinia WR but remains neurovirulent in mice and causes significant body weight loss after intranasal inoculation. Our data demonstrate the need for further attenuation of VTT to serve either as a safer smallpox vaccine or as a live vaccine vector for other pathogens.« less

Inhibition of allergic encephalomyelitis in marmosets by vaccination with recombinant vaccinia virus encoding for myelin basic protein.

PubMed

Genain, C P; Gritz, L; Joshi, N; Panicali, D; Davis, R L; Whitaker, J N; Letvin, N L; Hauser, S L

1997-11-01

A primary demyelinating form of experimental allergic encephalomyelitis (EAE) resembling human multiple sclerosis (MS) occurs in Callithrix jacchus marmosets following immunization with human white matter. Participation of a T-cell immune response against myelin basic protein (MBP) in this disease model is supported by observations of increased reactivity against MBP in PBMC and of adoptive transfer of an inflammatory form of EAE by MBP-reactive T-cells. To evaluate the effects of ectopic presentation of MBP on marmoset EAE, animals were vaccinated prior to induction of EAE by subcutaneous injection of attenuated strains of vaccinia virus genetically engineered to contain either the entire coding sequence for human MBP (vT15) or the equine herpes virus glycoprotein gH gene (vAbT249). Vaccination with vT15 was followed by transient cytoplasmic and surface membrane expression of MBP in circulating PBMC (15-45 days). The onset of clinical EAE after immunization (pi) was markedly delayed in vT15-vaccinated animals (37-97 days pi, n = 4) compared to vAbT249-vaccinated controls (14-18 days pi, n = 3). Proliferative responses against MBP but not against vaccinia antigens or phytohemagglutinin were suppressed in protected animals. Thus, development of attenuated live viruses carrying genes for myelin antigens could be useful for induction of immunologic tolerance and for modulation of autoimmune demyelination.

Potent Neutralization of Vaccinia Virus by Divergent Murine Antibodies Targeting a Common Site of Vulnerability in L1 Protein

PubMed Central

Kaever, Thomas; Meng, Xiangzhi; Matho, Michael H.; Schlossman, Andrew; Li, Sheng; Sela-Culang, Inbal; Ofran, Yanay; Buller, Mark; Crump, Ryan W.; Parker, Scott; Frazier, April; Crotty, Shane; Zajonc, Dirk M.; Peters, Bjoern

2014-01-01

ABSTRACT Vaccinia virus (VACV) L1 is an important target for viral neutralization and has been included in multicomponent DNA or protein vaccines against orthopoxviruses. To further understand the protective mechanism of the anti-L1 antibodies, we generated five murine anti-L1 monoclonal antibodies (MAbs), which clustered into 3 distinct epitope groups. While two groups of anti-L1 failed to neutralize, one group of 3 MAbs potently neutralized VACV in an isotype- and complement-independent manner. This is in contrast to neutralizing antibodies against major VACV envelope proteins, such as H3, D8, or A27, which failed to completely neutralize VACV unless the antibodies are of complement-fixing isotypes and complement is present. Compared to nonneutralizing anti-L1 MAbs, the neutralization antibodies bound to the recombinant L1 protein with a significantly higher affinity and also could bind to virions. By using a variety of techniques, including the isolation of neutralization escape mutants, hydrogen/deuterium exchange mass spectrometry, and X-ray crystallography, the epitope of the neutralizing antibodies was mapped to a conformational epitope with Asp35 as the key residue. This epitope is similar to the epitope of 7D11, a previously described potent VACV neutralizing antibody. The epitope was recognized mainly by CDR1 and CDR2 of the heavy chain, which are highly conserved among antibodies recognizing the epitope. These antibodies, however, had divergent light-chain and heavy-chain CDR3 sequences. Our study demonstrates that the conformational L1 epitope with Asp35 is a common site of vulnerability for potent neutralization by a divergent group of antibodies. IMPORTANCE Vaccinia virus, the live vaccine for smallpox, is one of the most successful vaccines in human history, but it presents a level of risk that has become unacceptable for the current population. Studying the immune protection mechanism of smallpox vaccine is important for understanding the basic

Mechanism of lymphocytic choriomeningitis virus entry into cells.

PubMed

Borrow, P; Oldstone, M B

1994-01-01

The path that the arenavirus lymphocytic choriomeningitis virus (LCMV) uses to enter rodent fibroblastic cell lines was dissected by infectivity and inhibition studies and immunoelectron microscopy. Lysosomotropic weak bases (chloroquine and ammonium chloride) and carboxylic ionophores (monensin and nigericin) inhibited virus entry, assessed as virus nucleoprotein expression at early times post-infection, indicating that the entry process involved a pH-dependent fusion step in intracellular vesicles. That entry occurred in vesicles rather than by direct fusion of virions with the plasma membrane was confirmed by immunoelectron microscopy. The vesicles involved were large (150-300 nm diameter), smooth-walled, and not associated with clathrin. Unlike classical phagocytosis, virus uptake in these vesicles was a microfilament-independent process, as it was not blocked by cytochalasins. LCMV entry into rodent fibroblast cell lines thus involves viropexis in large smooth-walled vesicles, followed by a pH-dependent fusion event inside the cell.

Characterizing Functional Domains for TIM-Mediated Enveloped Virus Entry

PubMed Central

Moller-Tank, Sven; Albritton, Lorraine M.; Rennert, Paul D.

2014-01-01

ABSTRACT T-cell immunoglobulin and mucin domain 1 (TIM-1) and other TIM family members were recently identified as phosphatidylserine (PtdSer)-mediated virus entry-enhancing receptors (PVEERs). These proteins enhance entry of Ebola virus (EBOV) and other viruses by binding PtdSer on the viral envelope, concentrating virus on the cell surface, and promoting subsequent internalization. The PtdSer-binding activity of the immunoglobulin-like variable (IgV) domain is essential for both virus binding and internalization by TIM-1. However, TIM-3, whose IgV domain also binds PtdSer, does not effectively enhance virus entry, indicating that other domains of TIM proteins are functionally important. Here, we investigate the domains supporting enhancement of enveloped virus entry, thereby defining the features necessary for a functional PVEER. Using a variety of chimeras and deletion mutants, we found that in addition to a functional PtdSer-binding domain PVEERs require a stalk domain of sufficient length, containing sequences that promote an extended structure. Neither the cytoplasmic nor the transmembrane domain of TIM-1 is essential for enhancing virus entry, provided the protein is still plasma membrane bound. Based on these defined characteristics, we generated a mimic lacking TIM sequences and composed of annexin V, the mucin-like domain of α-dystroglycan, and a glycophosphatidylinositol anchor that functioned as a PVEER to enhance transduction of virions displaying Ebola, Chikungunya, Ross River, or Sindbis virus glycoproteins. This identification of the key features necessary for PtdSer-mediated enhancement of virus entry provides a basis for more effective recognition of unknown PVEERs. IMPORTANCE T-cell immunoglobulin and mucin domain 1 (TIM-1) and other TIM family members are recently identified phosphatidylserine (PtdSer)-mediated virus entry-enhancing receptors (PVEERs). These proteins enhance virus entry by binding the phospholipid, PtdSer, present on the viral

Microbiota is an essential element for mice to initiate a protective immunity against Vaccinia virus.

PubMed

Lima, Maurício T; Andrade, Ana C S P; Oliveira, Graziele P; Calixto, Rafael S; Oliveira, Danilo B; Souza, Éricka L S; Trindade, Giliane S; Nicoli, Jacques R; Kroon, Erna G; Martins, Flaviano S; Abrahão, Jônatas S

2016-02-01

The gastrointestinal tract of vertebrates harbors one of the most complex ecosystems known in microbial ecology and this indigenous microbiota almost always has a profound influence on host-parasite relationships, which can enhance or reduce the pathology of the infection. In this context, the impact of the microbiota during the infection of several viral groups remains poorly studied, including the family Poxviridae. Vaccinia virus (VACV) is a member of this family and is the causative agent of bovine vaccinia, responsible for outbreaks that affect bovines and humans. To determine the influence of the microbiota in the development of the disease caused by VACV, a comparative study using a murine model was performed. Germ-free and conventional, 6- to 7-week-old Swiss NIH mice were infected by tail scarification and intranasally with VACV. Moreover, immunosuppression and microbiota reposition were performed, to establish the interactions among the host's immune system, microbiota and VACV. The data demonstrate that the microbiota is essential for the effective immune response of mice against VACV in intranasal inoculation and to control the virus at the primary site of infection. Furthermore, this study is the first to show that Swiss conventional mice are refractory to the intranasal infection of VACV. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Generation of Recombinant Modified Vaccinia Virus Ankara Encoding VP2, NS1, and VP7 Proteins of Bluetongue Virus.

PubMed

Marín-López, Alejandro; Ortego, Javier

2016-01-01

Modified Vaccinia Virus Ankara (MVA) is employed widely as an experimental vaccine vector for its lack of replication in mammalian cells and high expression level of foreign/heterologous genes. Recombinant MVAs (rMVAs) are used as platforms for protein production as well as vectors to generate vaccines against a high number of infectious diseases and other pathologies. The portrait of the virus combines desirable elements such as high-level biological safety, the ability to activate appropriate innate immune mediators upon vaccination, and the capacity to deliver substantial amounts of heterologous antigens. Recombinant MVAs encoding proteins of bluetongue virus (BTV), an Orbivirus that infects domestic and wild ruminants transmitted by biting midges of the Culicoides species, are excellent vaccine candidates against this virus. In this chapter we describe the methods for the generation of rMVAs encoding VP2, NS1, and VP7 proteins of bluetongue virus as a model example for orbiviruses. The protocols included cover the cloning of VP2, NS1, and VP7 BTV-4 genes in a transfer plasmid, the construction of recombinant MVAs, the titration of virus working stocks and the protein expression analysis by immunofluorescence and radiolabeling of rMVA infected cells as well as virus purification.

In vitro susceptibility to ST-246 and Cidofovir corroborates the phylogenetic separation of Brazilian Vaccinia virus into two clades.

PubMed

Pires, Mariana A; Rodrigues, Nathália F S; de Oliveira, Danilo B; de Assis, Felipe L; Costa, Galileu B; Kroon, Erna G; Mota, Bruno E F

2018-04-01

The Orthopoxvirus (OPV) genus of the Poxviridae family contains several human pathogens, including Vaccinia virus (VACV), which have been implicating in outbreaks of a zoonotic disease called Bovine Vaccinia in Brazil. So far, no approved treatment exists for OPV infections, but ST-246 and Cidofovir (CDV) are now in clinical development. Therefore, the objective of this work was to evaluate the susceptibility of five strains of Brazilian VACV (Br-VACV) to ST-246 and Cidofovir. The susceptibility of these strains to both drugs was evaluated by plaque reduction assay, extracellular virus's quantification in the presence of ST-246 and one-step growth curve in cells treated with CDV. Besides that, the ORFs F13L and E9L were sequenced for searching of polymorphisms associated with drug resistance. The effective concentration of 50% (EC 50 ) from both drugs varies significantly for different strains (from 0.0054 to 0.051 μM for ST-246 and from 27.14 to 61.23 μM for CDV). ST-246 strongly inhibits the production of extracellular virus for all isolates in concentrations as low as 0.1 μM and it was observed a relevant decrease of progeny production for all Br-VACV after CDV treatment. Sequencing of the F13L and E9L ORFs showed that Br-VACV do not present the polymorphism(s) associated with resistance to ST-246 and CDV. Taken together, our results showed that ST-246 and CDV are effective against diverse, wild VACV strains and that the susceptibility of Br-VACV to these drugs mirrored the phylogenetic split of these isolates into two groups. Thus, both ST-246 and CDV are of great interest as compounds to treat individuals during Bovine Vaccinia outbreaks in Brazil. Copyright © 2018 Elsevier B.V. All rights reserved.

Dynamic monitoring of membrane nanotubes formation induced by vaccinia virus on a high throughput microfluidic chip

NASA Astrophysics Data System (ADS)

Xiao, Min; Xu, Na; Wang, Cheng; Pang, Dai-Wen; Zhang, Zhi-Ling

2017-03-01

Membrane nanotubes (MNTs) are physical connections for intercellular communication and induced by various viruses. However, the formation of vaccinia virus (VACV)-induced MNTs has never been studied. In this report, VACV-induced MNTs formation process was monitored on a microfluidic chip equipped with a series of side chambers, which protected MNTs from fluidic shear stress. MNTs were formed between susceptible cells and be facilitated by VACV infection through three patterns. The formed MNTs varied with cell migration and virus concentration. The length of MNTs was positively correlated with the distance of cell migration. With increasing virus titer, the peak value of the ratio of MNT-carried cell appeared earlier. The immunofluorescence assay indicated that the rearrangement of actin fibers induced by VACV infection may lead to the formation of MNTs. This study presents evidence for the formation of MNTs induced by virus and helps us to understand the relationship between pathogens and MNTs.

Silk-elastin-like protein polymer matrix for intraoperative delivery of an oncolytic vaccinia virus.

PubMed

Price, Daniel L; Li, Pingdong; Chen, Chun-Hao; Wong, Danni; Yu, Zhenkun; Chen, Nanhai G; Yu, Yong A; Szalay, Aladar A; Cappello, Joseph; Fong, Yuman; Wong, Richard J

2016-02-01

Oncolytic viral efficacy may be limited by the penetration of the virus into tumors. This may be enhanced by intraoperative application of virus immediately after surgical resection. Oncolytic vaccinia virus GLV-1h68 was delivered in silk-elastin-like protein polymer (SELP) in vitro and in vivo in anaplastic thyroid carcinoma cell line 8505c in nude mice. GLV-1h68 in SELP infected and lysed anaplastic thyroid cancer cells in vitro equally as effectively as in phosphate-buffered saline (PBS), and at 1 week retains a thousand fold greater infectious plaque-forming units. In surgical resection models of residual tumor, GLV-1h68 in SELP improves tumor control and shows increased viral β-galactosidase expression as compared to PBS. The use of SELP matrix for intraoperative oncolytic viral delivery protects infectious viral particles from degradation, facilitates sustained viral delivery and transgene expression, and improves tumor control. Such optimization of methods of oncolytic viral delivery may enhance therapeutic outcomes. © 2014 Wiley Periodicals, Inc.

Targeted entry of enveloped viruses: measles and herpes simplex virus I.

PubMed

Navaratnarajah, Chanakha K; Miest, Tanner S; Carfi, Andrea; Cattaneo, Roberto

2012-02-01

We compare the receptor-based mechanisms that a small RNA virus and a larger DNA virus have evolved to drive the fusion of viral and cellular membranes. Both systems rely on tight control over triggering the concerted refolding of a trimeric fusion protein. While measles virus entry depends on a receptor-binding protein and a fusion protein only, the herpes simplex virus (HSV) is more complex and requires four viral proteins. Nevertheless, in both viruses a receptor-binding protein is required for triggering the membrane fusion process. Moreover, specificity domains can be appended to these receptor-binding proteins to target virus entry to cells expressing a designated receptor. We discuss how principles established with measles and HSV can be applied to targeting other enveloped viruses, and alternatively how retargeted envelopes can be fitted on foreign capsids. Copyright © 2011 Elsevier B.V. All rights reserved.

Modified Vaccinia Virus Ankara Vector Induces Specific Cellular and Humoral Responses in the Female Reproductive Tract, the Main HIV Portal of Entry.

PubMed

Marlin, Romain; Nugeyre, Marie-Thérèse; Tchitchek, Nicolas; Parenti, Matteo; Hocini, Hakim; Benjelloun, Fahd; Cannou, Claude; Dereuddre-Bosquet, Nathalie; Levy, Yves; Barré-Sinoussi, Françoise; Scarlatti, Gabriella; Le Grand, Roger; Menu, Elisabeth

2017-09-01

The female reproductive tract (FRT) is one of the major mucosal invasion sites for HIV-1. This site has been neglected in previous HIV-1 vaccine studies. Immune responses in the FRT after systemic vaccination remain to be characterized. Using a modified vaccinia virus Ankara (MVA) as a vaccine model, we characterized specific immune responses in all compartments of the FRT of nonhuman primates after systemic vaccination. Memory T cells were preferentially found in the lower tract (vagina and cervix), whereas APCs and innate lymphoid cells were mainly located in the upper tract (uterus and fallopian tubes). This compartmentalization of immune cells in the FRT was supported by transcriptomic analyses and a correlation network. Polyfunctional MVA-specific CD8 + T cells were detected in the blood, lymph nodes, vagina, cervix, uterus, and fallopian tubes. Anti-MVA IgG and IgA were detected in cervicovaginal fluid after a second vaccine dose. Thus, systemic vaccination with an MVA vector elicits cellular and Ab responses in the FRT. Copyright © 2017 by The American Association of Immunologists, Inc.

Multiscale Modeling of Virus Entry via Receptor-Mediated Endocytosis

NASA Astrophysics Data System (ADS)

Liu, Jin

2012-11-01

Virus infections are ubiquitous and remain major threats to human health worldwide. Viruses are intracellular parasites and must enter host cells to initiate infection. Receptor-mediated endocytosis is the most common entry pathway taken by viruses, the whole process is highly complex and dictated by various events, such as virus motions, membrane deformations, receptor diffusion and ligand-receptor reactions, occurring at multiple length and time scales. We develop a multiscale model for virus entry through receptor-mediated endocytosis. The binding of virus to cell surface is based on a mesoscale three dimensional stochastic adhesion model, the internalization (endocytosis) of virus and cellular membrane deformation is based on the discretization of Helfrich Hamiltonian in a curvilinear space using Monte Carlo method. The multiscale model is based on the combination of these two models. We will implement this model to study the herpes simplex virus entry into B78 cells and compare the model predictions with experimental measurements.

TIM-1 Mediates Dystroglycan-Independent Entry of Lassa Virus.

PubMed

Brouillette, Rachel B; Phillips, Elisabeth K; Patel, Radhika; Mahauad-Fernandez, Wadie; Moller-Tank, Sven; Rogers, Kai J; Dillard, Jacob A; Cooney, Ashley L; Martinez-Sobrido, Luis; Okeoma, Chioma; Maury, Wendy

2018-06-06

Lassa virus (LASV) is an Old World arenavirus responsible for hundreds of thousands of infections in West Africa every year. LASV entry into a variety of cell types is mediated by interactions with glycosyltransferase LARGE-modified O-linked glycans present on the ubiquitous receptor, α-dystroglycan (αDG). Yet, cells lacking αDG are permissive to LASV infection, suggesting that alternative receptors exist. Previous studies demonstrate that phosphatidylserine (PtdSer)-binding receptors, Axl and Tyro3 along with C-type lectin receptors, mediate αDG-independent entry. Here, we demonstrate that another PtdSer receptor, TIM-1, mediates LASV glycoprotein (GP) pseudotyped virions entry into αDG knocked out HEK 293T and wild-type (WT) Vero which express αDG lacking appropriate glycosylation. To investigate the mechanism by which TIM-1 mediates enhancement of entry, we demonstrate that mutagenesis of the TIM-1 IgV domain PtdSer-binding pocket abrogated transduction. Further, the human TIM-1 IgV domain binding monoclonal antibody, ARD5, blocked transduction of pseudovirions bearing LASV GP in a dose-dependent manner. Finally, as we showed previously for other viruses that use TIM-1 for entry, a chimeric TIM-1 protein that substitutes the proline rich region (PRR) from murine leukemia virus envelope (Env) for the mucin-like domain served as a competent receptor. These studies provide evidence that, in the absence of a functional αDG, TIM-1 mediates entry of LASV pseudoviral particles through interactions of virions with the IgV PtdSer binding pocket of TIM-1. Importance PtdSer receptors, such as TIM-1, are emerging as critical entry factors for many enveloped viruses. Most recently, Hepatitis C virus and Zika virus have been added to a growing list. PtdSer receptors engage with enveloped viruses through binding of PtdSer embedded in the viral envelope, defining them as GP-independent receptors. This GP-independent entry mechanism should effectively mediate entry of all

Ectromelia virus accumulates less double-stranded RNA compared to vaccinia virus in BS-C-1 cells.

PubMed

Frey, Tiffany R; Lehmann, Michael H; Ryan, Colton M; Pizzorno, Marie C; Sutter, Gerd; Hersperger, Adam R

2017-09-01

Most orthopoxviruses, including vaccinia virus (VACV), contain genes in the E3L and K3L families. The protein products of these genes have been shown to combat PKR, a host defense pathway. Interestingly, ectromelia virus (ECTV) contains an E3L ortholog but does not possess an intact K3L gene. Here, we gained insight into how ECTV can still efficiently evade PKR despite lacking K3L. Relative to VACV, we found that ECTV-infected BS-C-1 cells accumulated considerably less double-stranded (ds) RNA, which was due to lower mRNA levels and less transcriptional read-through of some genes by ECTV. The abundance of dsRNA in VACV-infected cells, detected using a monoclonal antibody, was able to activate the RNase L pathway at late time points post-infection. Historically, the study of transcription by orthopoxviruses has largely focused on VACV as a model. Our data suggest that there could be more to learn by studying other members of this genus. Copyright © 2017 Elsevier Inc. All rights reserved.

INTRACELLULAR FORMS OF POX VIRUSES AS SHOWN BY THE ELECTRON MICROSCOPE (VACCINIA, ECTROMELIA, MOLLUSCUM CONTAGIOSUM)

PubMed Central

Gaylord, William H.; Melnick, Joseph L.

1953-01-01

The intracellular development of three pox viruses has been studied with the electron microscope using thin sections of infected tissue. Cells infected with vaccinia, ectromelia, and molluscum contagiosum viruses all form developmental bodies preliminary to the production of mature virus. Developmental bodies, believed to be virus precursors, are round to oval, slightly larger than mature virus particles, less dense to electrons, and have a more varied morphology. It is suggested as a working hypothesis that the process of maturation of a virus particle takes place as follows. In the earliest form the developmental bodies appear as hollow spheres, imbedded in a very dense cytoplasmic mass constituting an inclusion body, or in a less dense matrix near the nucleus in cells without typical inclusion bodies. The spheres become filled with a homogeneous material of low electron density. A small, dense granule appears in each developmental body and grows in size at the expense of the low density material. Following growth of the granule, particles are found with the dimensions of mature virus and having complex internal structure resembling bars or dumbells. Mature virus is ovoid and very dense to electrons. An "empty" interior may be found within its thick walls. PMID:13069658

Nipah virus entry can occur by macropinocytosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pernet, Olivier; Pohl, Christine; Ainouze, Michelle

2009-12-20

Nipah virus (NiV) is a zoonotic biosafety level 4 paramyxovirus that emerged recently in Asia with high mortality in man. NiV is a member, with Hendra virus (HeV), of the Henipavirus genus in the Paramyxoviridae family. Although NiV entry, like that of other paramyxoviruses, is believed to occur via pH-independent fusion with the host cell's plasma membrane we present evidence that entry can occur by an endocytic pathway. The NiV receptor ephrinB2 has receptor kinase activity and we find that ephrinB2's cytoplasmic domain is required for entry but is dispensable for post-entry viral spread. The mutation of a single tyrosinemore » residue (Y304F) in ephrinB2's cytoplasmic tail abrogates NiV entry. Moreover, our results show that NiV entry is inhibited by constructions and drugs specific for the endocytic pathway of macropinocytosis. Our findings could potentially permit the rapid development of novel low-cost antiviral treatments not only for NiV but also HeV.« less

Vaccinia immune globulin: current policies, preparedness, and product safety and efficacy.

PubMed

Wittek, Riccardo

2006-05-01

In 1980 the World Health Organization declared that smallpox was eradicated from the world, and routine smallpox vaccination was discontinued. Nevertheless, samples of the smallpox virus (variola virus) were retained for research purposes, not least because of fears that terrorist groups or rogue states might also have kept samples in order to develop a bioweapon. Variola virus represents an effective bioweapon because it is associated with high morbidity and mortality and is highly contagious. Since September 11, 2001, countries around the world have begun to develop policies and preparedness programs to deal with a bioterror attack, including stockpiling of smallpox vaccine. Smallpox vaccine itself may be associated with a number of serious adverse events, which can often be managed with vaccinia immune globulin (VIG). VIG may also be needed as prophylaxis in patients for whom pre-exposure smallpox vaccine is contraindicated (such as those with eczema or pregnant women), although it is currently not licensed in these cases. Two intravenous formulations of VIG (VIGIV Cangene and VIGIV Dynport) have been licensed by the FDA for the management of patients with progressive vaccinia, eczema vaccinatum, severe generalized vaccinia, and extensive body surface involvement or periocular implantation following inadvertent inoculation.

Protection of Mice from Fatal Measles Encephalitis by Vaccination with Vaccinia Virus Recombinants Encoding Either the Hemagglutinin or the Fusion Protein

NASA Astrophysics Data System (ADS)

Drillien, Robert; Spehner, Daniele; Kirn, Andre; Giraudon, Pascale; Buckland, Robin; Wild, Fabian; Lecocq, Jean-Pierre

1988-02-01

Vaccinia virus recombinants encoding the hemagglutinin or fusion protein of measles virus have been constructed. Infection of cell cultures with the recombinants led to the synthesis of authentic measles proteins as judged by their electrophoretic mobility, recognition by antibodies, glycosylation, proteolytic cleavage, and presentation on the cell surface. Mice vaccinated with a single dose of the recombinant encoding the hemagglutinin protein developed antibodies capable of both inhibiting hemagglutination activity and neutralizing measles virus, whereas animals vaccinated with the recombinant encoding the fusion protein developed measles neutralizing antibodies. Mice vaccinated with either of the recombinants resisted a normally lethal intracerebral inoculation of a cell-associated measles virus subacute sclerosing panencephalitis strain.

Distinct gene expression profiles in peripheral blood mononuclear cells from patients infected with vaccinia virus, yellow fever 17D virus, or upper respiratory infections.

PubMed

Scherer, Christina A; Magness, Charles L; Steiger, Kathryn V; Poitinger, Nicholas D; Caputo, Christine M; Miner, Douglas G; Winokur, Patricia L; Klinzman, Donna; McKee, Janice; Pilar, Christine; Ward, Patricia A; Gillham, Martha H; Haulman, N Jean; Stapleton, Jack T; Iadonato, Shawn P

2007-08-29

Gene expression in human peripheral blood mononuclear cells was systematically evaluated following smallpox and yellow fever vaccination, and naturally occurring upper respiratory infection (URI). All three infections were characterized by the induction of many interferon stimulated genes, as well as enhanced expression of genes involved in proteolysis and antigen presentation. Vaccinia infection was also characterized by a distinct expression signature composed of up-regulation of monocyte response genes, with repression of genes expressed by B and T-cells. In contrast, the yellow fever host response was characterized by a suppression of ribosomal and translation factors, distinguishing this infection from vaccinia and URI. No significant URI-specific signature was observed, perhaps reflecting greater heterogeneity in the study population and etiological agents. Taken together, these data suggest that specific host gene expression signatures may be identified that distinguish one or a small number of virus agents.

Mucosal Vaccination Overcomes the Barrier to Recombinant Vaccinia Immunization Caused by Preexisting Poxvirus Immunity

NASA Astrophysics Data System (ADS)

Belyakov, Igor M.; Moss, Bernard; Strober, Warren; Berzofsky, Jay A.

1999-04-01

Overcoming preexisting immunity to vaccinia virus in the adult population is a key requirement for development of otherwise potent recombinant vaccinia vaccines. Based on our observation that s.c. immunization with vaccinia induces cellular and antibody immunity to vaccinia only in systemic lymphoid tissue and not in mucosal sites, we hypothesized that the mucosal immune system remains naive to vaccinia and therefore amenable to immunization with recombinant vaccinia vectors despite earlier vaccinia exposure. We show that mucosal immunization of vaccinia-immune BALB/c mice with recombinant vaccinia expressing HIV gp160 induced specific serum antibody and strong HIV-specific cytotoxic T lymphocyte responses. These responses occurred not only in mucosal but also in systemic lymphoid tissue, whereas systemic immunization was ineffective under these circumstances. In this context, intrarectal immunization was more effective than intranasal immunization. Boosting with a second dose of recombinant vaccinia was also more effective via the mucosal route. The systemic HIV-specific cytotoxic T lymphocyte response was enhanced by coadministration of IL-12 at the mucosal site. These results also demonstrate the independent compartmentalization of the mucosal versus systemic immune systems and the asymmetric trafficking of lymphocytes between them. This approach to circumvent previous vaccinia immunity may be useful for induction of protective immunity against infectious diseases and cancer in the sizable populations with preexisting immunity to vaccinia from smallpox vaccination.

Entry of Human Papillomavirus Type 16 by Actin-Dependent, Clathrin- and Lipid Raft-Independent Endocytosis

PubMed Central

Schelhaas, Mario; Shah, Bhavin; Holzer, Michael; Blattmann, Peter; Kühling, Lena; Day, Patricia M.; Schiller, John T.; Helenius, Ari

2012-01-01

Infectious endocytosis of incoming human papillomavirus type 16 (HPV-16), the main etiological agent of cervical cancer, is poorly characterized in terms of cellular requirements and pathways. Conflicting reports attribute HPV-16 entry to clathrin-dependent and -independent mechanisms. To comprehensively describe the cell biological features of HPV-16 entry into human epithelial cells, we compared HPV-16 pseudovirion (PsV) infection in the context of cell perturbations (drug inhibition, siRNA silencing, overexpression of dominant mutants) to five other viruses (influenza A virus, Semliki Forest virus, simian virus 40, vesicular stomatitis virus, and vaccinia virus) with defined endocytic requirements. Our analysis included infection data, i.e. GFP expression after plasmid delivery by HPV-16 PsV, and endocytosis assays in combination with electron, immunofluorescence, and video microscopy. The results indicated that HPV-16 entry into HeLa and HaCaT cells was clathrin-, caveolin-, cholesterol- and dynamin-independent. The virus made use of a potentially novel ligand-induced endocytic pathway related to macropinocytosis. This pathway was distinct from classical macropinocytosis in regards to vesicle size, cholesterol-sensitivity, and GTPase requirements, but similar in respect to the need for tyrosine kinase signaling, actin dynamics, Na+/H+ exchangers, PAK-1 and PKC. After internalization the virus was transported to late endosomes and/or endolysosomes, and activated through exposure to low pH. PMID:22536154

Human CD4 T cell epitopes selective for Vaccinia versus Variola virus.

PubMed

Probst, Alicia; Besse, Aurore; Favry, Emmanuel; Imbert, Gilles; Tanchou, Valérie; Castelli, Florence Anne; Maillere, Bernard

2013-04-01

Due to the high degree of sequence identity between Orthopoxvirus species, the specific B and T cell responses raised against these viruses are largely cross-reactive and poorly selective. We therefore searched for CD4 T cell epitopes present in the conserved parts of the Vaccinia genome (VACV) but absent from Variola viruses (VARV), with a view to identifying immunogenic sequences selective for VACV. We identified three long peptide fragments from the B7R, B10R and E7R proteins by in silico comparisons of the poxvirus genomes, and evaluated the recognition of these fragments by VACV-specific T cell lines derived from healthy donors. For the 12 CD4 T cell epitopes identified, we assessed their binding to common HLA-DR allotypes and their capacity to induce peptide-specific CD4 T-cell lines. Four peptides from B7R and B10R displayed a broad binding specificity for HLA-DR molecules and induced multiple T cell lines from healthy donors. Besides their absence from VARV, the two B10R peptide sequences were mutated in the Cowpox virus and completely absent from the Monkeypox genome. This work contributes to the development of differential diagnosis of poxvirus infections. Copyright © 2012 Elsevier Ltd. All rights reserved.

Silk-elastin-like protein polymer matrix for intraoperative delivery of an oncolytic vaccinia virus

PubMed Central

Price, Daniel L.; Li, Pingdong; Chen, Chun-Hao; Wong, Danni; Yu, Zhenkun; Chen, Nanhai G.; Yu, Yong A.; Szalay, Aladar A.; Cappello, Joseph; Fong, Yuman; Wong, Richard J.

2016-01-01

Background Oncolytic viral efficacy may be limited by the penetration of the virus into tumors. This may be enhanced by intraoperative application of virus immediately after surgical resection. Methods Oncolytic vaccinia virus GLV-1h68 was delivered in silk-elastin-like protein polymer (SELP) in vitro and in vivo in anaplastic thyroid carcinoma cell line 8505c in nude mice. Results GLV-1h68 in SELP infected and lysed anaplastic thyroid cancer cells in vitro equally as effectively as in phosphate-buffered saline (PBS), and at 1 week retains a thousand fold greater infectious plaque-forming units. In surgical resection models of residual tumor, GLV-1h68 in SELP improves tumor control and shows increased viral β-galactosidase expression as compared to PBS. Conclusion The use of SELP matrix for intraoperative oncolytic viral delivery protects infectious viral particles from degradation, facilitates sustained viral delivery and transgene expression, and improves tumor control. Such optimization of methods of oncolytic viral delivery may enhance therapeutic outcomes. PMID:25244076

Activation of Paramyxovirus Membrane Fusion and Virus Entry

PubMed Central

Jardetzky, Theodore S.; Lamb, Robert A.

2014-01-01

The paramyxoviruses represent a diverse virus family responsible for a wide range of human and animal diseases. In contrast to other viruses, such as HIV and influenza virus, which use a single glycoprotein to mediate host receptor binding and virus entry, the paramyxoviruses require two distinct proteins. One of these is an attachment glycoprotein that binds receptor, while the second is a fusion glycoprotein, which undergoes conformational changes that drive virus-cell membrane fusion and virus entry. The details of how receptor binding by one protein activates the second to undergo conformational changes have been poorly understood until recently. Over the past couple of years, structural and functional data have accumulated on representative members of this family, including parainfluenza virus 5, Newcastle disease virus, measles virus, Nipah virus and others, which suggest a mechanistic convergence of activation models. Here we review the data indicating that paramyxovirus attachment glycoproteins shield activating residues within their N-terminal stalk domains, which are then exposed upon receptor binding, leading to the activation of the fusion protein by a ‘provocateur’ mechanism. PMID:24530984

Single-Virus Fusion Experiments Reveal Proton Influx into Vaccinia Virions and Hemifusion Lag Times

PubMed Central

Schmidt, Florian I.; Kuhn, Phillip; Robinson, Tom; Mercer, Jason; Dittrich, Petra S.

2013-01-01

Recent studies have revealed new insights into the endocytosis of vaccinia virus (VACV). However, the mechanism of fusion between viral and cellular membranes remains unknown. We developed a microfluidic device with a cell-trap array for immobilization of individual cells, with which we analyzed the acid-dependent fusion of single virions. VACV particles incorporating enhanced green fluorescent protein (EGFP) and labeled with self-quenching concentrations of R18 membrane dye were used in combination with total internal reflection fluorescence microscopy to measure the kinetics of R18 dequenching and thus single hemifusion events initiated by a fast low-pH trigger. These studies revealed unexpectedly long lag phases between pH change and hemifusion. In addition, we found that EGFP fluorescence in the virus was quenched upon acidification, indicating that protons could access the virus core, possibly through a proton channel. In a fraction of virus particles, EGFP fluorescence was recovered, presumably after fusion-pore formation and exposure of the core to the physiological pH of the host-cell cytosol. Given that virus-encoded cation channels play a crucial role in the life cycle of many viruses and can serve as antiviral drug targets, further investigations into a potential VACV viroporin are justified. Our findings indicate that the microfluidic device described may be highly beneficial to similar studies requiring fast kinetic measurements. PMID:23870263

From Lesions to Viral Clones: Biological and Molecular Diversity amongst Autochthonous Brazilian Vaccinia Virus

PubMed Central

Oliveira, Graziele; Assis, Felipe; Almeida, Gabriel; Albarnaz, Jonas; Lima, Maurício; Andrade, Ana Cláudia; Calixto, Rafael; Oliveira, Cairo; Neto, José Diomedes; Trindade, Giliane; Ferreira, Paulo César; Kroon, Erna Geessien; Abrahão, Jônatas

2015-01-01

Vaccinia virus (VACV) has had an important role for humanity because of its use during the smallpox eradication campaign. VACV is the etiologic agent of the bovine vaccinia (BV), an emerging zoonosis that has been associated with economic, social, veterinary and public health problems, mainly in Brazil and India. Despite the current and historical VACV importance, there is little information about its circulation, prevalence, origins and maintenance in the environment, natural reservoirs and diversity. Brazilian VACV (VACV-BR) are grouped into at least two groups based on genetic and biological diversity: group 1 (G1) and group 2 (G2). In this study, we went to the field and investigated VACV clonal diversity directly from exanthemous lesions, during BV outbreaks. Our results demonstrate that the G1 VACV-BR were more frequently isolated. Furthermore, we were able to co-detect the two variants (G1 and G2) in the same sample. Molecular and biological analysis corroborated previous reports and confirmed the co-circulation of two VACV-BR lineages. The detected G2 clones presented exclusive genetic and biological markers, distinct to reference isolates, including VACV-Western Reserve. Two clones presented a mosaic profile, with both G1 and G2 features based on the molecular analysis of A56R, A26L and C23L genes. Indeed, some SNPs and INDELs in A56R nucleotide sequences were observed among clones of the same virus population, maybe as a result of an increased mutation rate in a mixed population. These results provide information about the diversity profile in VACV populations, highlighting its importance to VACV evolution and maintenance in the environment. PMID:25785515

Vaccinia Virus Virulence Factor N1L is a Novel Promising Target for Antiviral Therapeutic Intervention

PubMed Central

Cheltsov, Anton V.; Aoyagi, Mika; Aleshin, Alexander; Chi-Wang, Yu Eric; Gilliland, Taylor; Zhai, Dayong; Bobkov, Andrey A.; Reed, John C.; Liddington, Robert C.; Abagyan, Ruben

2010-01-01

The 14 kDa homodimeric N1L protein is a potent vaccinia and variola (smallpox) virulence factor. It is not essential for viral replication, but it causes a strong attenuation of viral production in culture when deleted. The N1L protein is predicted to contain the BH3-like binding domain characteristic of Bcl-2 family proteins, and it is able to bind the BH3 peptides. Its overexpression has been reported to prevent infected cells from committing apoptosis. Therefore, interfering with the N1L apoptotic blockade may be a legitimate therapeutic strategy affecting the viral growth. By using in silico ligand docking and an array of in vitro assays, we have identified sub-micromolar (600 nM) N1L antagonists, belonging to the family of polyphenols. Their affinity is comparable to that of the BH3 peptides (70 nM ÷ 1000 nM). We have also identified the natural polyphenol resveratrol as a moderate N1L inhibitor. Finally, we show that our ligands efficiently inhibit growth of vaccinia virus. PMID:20441222

De novo Fatty Acid Biosynthesis Contributes Significantly to Establishment of a Bioenergetically Favorable Environment for Vaccinia Virus Infection

PubMed Central

Greseth, Matthew D.; Traktman, Paula

2014-01-01

The poxvirus life cycle, although physically autonomous from the host nucleus, is nevertheless dependent upon cellular functions. A requirement for de novo fatty acid biosynthesis was implied by our previous demonstration that cerulenin, a fatty acid synthase inhibitor, impaired vaccinia virus production. Here we show that additional inhibitors of this pathway, TOFA and C75, reduce viral yield significantly, with partial rescue provided by exogenous palmitate, the pathway's end-product. Palmitate's major role during infection is not for phospholipid synthesis or protein palmitoylation. Instead, the mitochondrial import and β-oxidation of palmitate are essential, as shown by the impact of etomoxir and trimetazidine, which target these two processes respectively. Moreover, the impact of these inhibitors is exacerbated in the absence of exogenous glucose, which is otherwise dispensable for infection. In contrast to glucose, glutamine is essential for productive viral infection, providing intermediates that sustain the TCA cycle (anaplerosis). Cumulatively, these data suggest that productive infection requires the mitochondrial β-oxidation of palmitate which drives the TCA cycle and energy production. Additionally, infection causes a significant rise in the cellular oxygen consumption rate (ATP synthesis) that is ablated by etomoxir. The biochemical progression of the vaccinia life cycle is not impaired in the presence of TOFA, C75, or etomoxir, although the levels of viral DNA and proteins synthesized are somewhat diminished. However, by reversibly arresting infections at the onset of morphogenesis, and then monitoring virus production after release of the block, we determined that virion assembly is highly sensitive to TOFA and C75. Electron microscopic analysis of cells released into C75 revealed fragmented aggregates of viroplasm which failed to be enclosed by developing virion membranes. Taken together, these data indicate that vaccinia infection, and in

De novo fatty acid biosynthesis contributes significantly to establishment of a bioenergetically favorable environment for vaccinia virus infection.

PubMed

Greseth, Matthew D; Traktman, Paula

2014-03-01

The poxvirus life cycle, although physically autonomous from the host nucleus, is nevertheless dependent upon cellular functions. A requirement for de novo fatty acid biosynthesis was implied by our previous demonstration that cerulenin, a fatty acid synthase inhibitor, impaired vaccinia virus production. Here we show that additional inhibitors of this pathway, TOFA and C75, reduce viral yield significantly, with partial rescue provided by exogenous palmitate, the pathway's end-product. Palmitate's major role during infection is not for phospholipid synthesis or protein palmitoylation. Instead, the mitochondrial import and β-oxidation of palmitate are essential, as shown by the impact of etomoxir and trimetazidine, which target these two processes respectively. Moreover, the impact of these inhibitors is exacerbated in the absence of exogenous glucose, which is otherwise dispensable for infection. In contrast to glucose, glutamine is essential for productive viral infection, providing intermediates that sustain the TCA cycle (anaplerosis). Cumulatively, these data suggest that productive infection requires the mitochondrial β-oxidation of palmitate which drives the TCA cycle and energy production. Additionally, infection causes a significant rise in the cellular oxygen consumption rate (ATP synthesis) that is ablated by etomoxir. The biochemical progression of the vaccinia life cycle is not impaired in the presence of TOFA, C75, or etomoxir, although the levels of viral DNA and proteins synthesized are somewhat diminished. However, by reversibly arresting infections at the onset of morphogenesis, and then monitoring virus production after release of the block, we determined that virion assembly is highly sensitive to TOFA and C75. Electron microscopic analysis of cells released into C75 revealed fragmented aggregates of viroplasm which failed to be enclosed by developing virion membranes. Taken together, these data indicate that vaccinia infection, and in

Rabbitpox virus and vaccinia virus infection of rabbits as a model for human smallpox.

PubMed

Adams, Mathew M; Rice, Amanda D; Moyer, R W

2007-10-01

The threat of smallpox release and use as a bioweapon has encouraged the search for new vaccines and antiviral drugs, as well as development of new small-animal models in which their efficacy can be determined. Here, we reinvestigate a rabbit model in which the intradermal infection of rabbits with very low doses of either rabbitpox virus (RPV) or vaccinia virus Western Reserve (VV-WR) recapitulates many of the clinical features of human smallpox. Following intradermal inoculation with RPV, rabbits develop systemic disease characterized by extensive viremia, numerous secondary lesions on the skin and mucocutaneous tissues, severe respiratory disease, death by 9 days postinfection, and, importantly, natural aerosol transmission between animals. Contrary to previous reports, intradermal infection with VV-WR also resulted in a very similar lethal systemic disease in rabbits, again with natural aerosol transmission between animals. When sentinel and index animals were cohoused, transmission rates approached 100% with either virus, with sentinel animals exhibiting a similar, severe disease. Lower rates of transmission were observed when index and sentinel animals were housed in separate cages. Sentinel animals infected with RPV with one exception succumbed to the disease. However, the majority of VV-WR-infected sentinel animals, while becoming seriously ill, survived. Finally, we tested the efficacy of the drug 1-O-hexadecyloxypropyl-cidofovir in the RPV/rabbit model and found that an oral dose of 5 mg/kg twice a day for 5 days beginning 1 day before infection was able to completely protect rabbits from lethal disease.

Vaccinia Virus C9 Ankyrin Repeat/F-Box Protein Is a Newly Identified Antagonist of the Type I Interferon-Induced Antiviral State.

PubMed

Liu, Ruikang; Moss, Bernard

2018-05-01

Type I interferons (IFNs) induce expression of more than 300 cellular genes that provide protection against viruses and other pathogens. For survival, viruses evolved defenses to prevent the IFN response or counteract the IFN-induced antiviral state. However, because viruses and cells coevolved, the dynamic relationship between virus and host is difficult to discern. In the present study, we demonstrated that vaccinia virus with a large deletion near the left end of the genome had a diminished ability to replicate in cells that had been pretreated with beta interferon (IFN-β), suggesting that one or more of the missing 17 open reading frames (ORFs) encode an antagonist of the IFN-induced antiviral state. By systematically deleting groups of ORFs and then individual ORFs, the C9L gene was shown to be required for IFN resistance. Replication of the C9L deletion mutant (vΔC9) was impaired in human cells that had been pretreated with IFN-β. Expression of viral early genes occurred, but subsequent events, including genome uncoating, genome replication, and postreplicative gene expression, were inhibited. Expression of the C9 protein occurred prior to genome replication, consistent with an early role in counteracting the IFN-induced antiviral state. C9 contains six ankyrin repeat motifs and a near C-terminal F-box. Mass spectrometry and immunoblotting identified host proteins that copurified with a functional epitope-tagged C9. The most abundant proteins were components of the SCF (CUL1, SKP1, F-box) and signalosome/deneddylation complexes, which interact with each other, suggesting a possible role in proteolysis of one or more interferon-induced proteins. IMPORTANCE Poxviruses comprise a family of large DNA viruses that replicate in the cytoplasm of vertebrate and insect hosts and cause human and zoonotic diseases. In most cases the primary infection is moderated by innate immune defenses. Vertebrates, including fish, amphibians, reptiles, birds, and mammals, all

Immunogenicity of modified vaccinia virus Ankara expressing the hemagglutinin stalk domain of pandemic (H1N1) 2009 influenza virus.

PubMed

Di Mario, Giuseppina; Soprana, Elisa; Gubinelli, Francesco; Panigada, Maddalena; Facchini, Marzia; Fabiani, Concetta; Garulli, Bruno; Basileo, Michela; Cassone, Antonio; Siccardi, Antonio; Donatelli, Isabella; Castrucci, Maria R

2017-03-01

Vaccination offers protection against influenza, although current vaccines need to be reformulated each year. The development of a broadly protective influenza vaccine would guarantee the induction of heterosubtypic immunity also against emerging influenza viruses of a novel subtype. Vaccine candidates based on the stalk region of the hemagglutinin (HA) have the potential to induce broad and persistent protection against diverse influenza A viruses. Modified vaccinia virus Ankara (MVA) expressing a headless HA (hlHA) of A/California/4/09 (CA/09) virus was used as a vaccine to immunize C57BL/6 mice. Specific antibody and cell-mediated immune responses were determined, and challenge experiments were performed by infecting vaccinated mice with CA/09 virus. Immunization of mice with CA/09-derived hlHA, vectored by MVA, was able to elicit influenza-specific broad cross-reactive antibodies and cell-mediated immune responses, but failed to induce neutralizing antibodies and did not protect mice against virus challenge. Although highly immunogenic, our vaccine was unable to induce a protective immunity against influenza. A misfolded and unstable conformation of the hlHA molecule may have affected its capacity of inducing neutralizing antiviral, conformational antibodies. Design of stable hlHA-based immunogens and their delivery by recombinant MVA-based vectors has the potential of improving this promising approach for a universal influenza vaccine.

Development and Evaluation of Single Domain Antibodies for Vaccinia and the L1 Antigen

PubMed Central

Walper, Scott A.; Liu, Jinny L.; Zabetakis, Daniel; Anderson, George P.; Goldman, Ellen R.

2014-01-01

There is ongoing interest to develop high affinity, thermal stable recognition elements to replace conventional antibodies in biothreat detection assays. As part of this effort, single domain antibodies that target vaccinia virus were developed. Two llamas were immunized with killed viral particles followed by boosts with the recombinant membrane protein, L1, to stimulate the immune response for envelope and membrane proteins of the virus. The variable domains of the induced heavy chain antibodies were selected from M13 phage display libraries developed from isolated RNA. Selection via biopanning on the L1 antigen produced single domain antibodies that were specific and had affinities ranging from 4×10−9 M to 7.0×10−10 M, as determined by surface plasmon resonance. Several showed good ability to refold after heat denaturation. These L1-binding single domain antibodies, however, failed to recognize the killed vaccinia antigen. Useful vaccinia binding single domain antibodies were isolated by a second selection using the killed virus as the target. The virus binding single domain antibodies were incorporated in sandwich assays as both capture and tracer using the MAGPIX system yielding limits of detection down to 4×105 pfu/ml, a four-fold improvement over the limit obtained using conventional antibodies. This work demonstrates the development of anti-vaccinia single domain antibodies and their incorporation into sandwich assays for viral detection. It also highlights the properties of high affinity and thermal stability that are hallmarks of single domain antibodies. PMID:25211488

Priming-boosting vaccination with recombinant Mycobacterium bovis bacillus Calmette-Guérin and a nonreplicating vaccinia virus recombinant leads to long-lasting and effective immunity.

PubMed

Ami, Yasushi; Izumi, Yasuyuki; Matsuo, Kazuhiro; Someya, Kenji; Kanekiyo, Masaru; Horibata, Shigeo; Yoshino, Naoto; Sakai, Koji; Shinohara, Katsuaki; Matsumoto, Sohkichi; Yamada, Takeshi; Yamazaki, Shudo; Yamamoto, Naoki; Honda, Mitsuo

2005-10-01

Virus-specific T-cell responses can limit immunodeficiency virus type 1 (HIV-1) transmission and prevent disease progression and so could serve as the basis for an affordable, safe, and effective vaccine in humans. To assess their potential for a vaccine, we used Mycobacterium bovis bacillus Calmette-Guérin (BCG)-Tokyo and a replication-deficient vaccinia virus strain (DIs) as vectors to express full-length gag from simian immunodeficiency viruses (SIVs) (rBCG-SIVgag and rDIsSIVgag). Cynomolgus macaques were vaccinated with either rBCG-SIVgag dermally as a single modality or in combination with rDIsSIVgag intravenously. When cynomologus macaques were primed with rBCG-SIVgag and then boosted with rDIsSIVgag, high levels of gamma interferon (IFN-gamma) spot-forming cells specific for SIV Gag were induced. This combination regimen elicited effective protective immunity against mucosal challenge with pathogenic simian-human immunodeficiency virus for the 1 year the macaques were under observation. Antigen-specific intracellular IFN-gamma activity was similarly induced in each of the macaques with the priming-boosting regimen. Other groups receiving the opposite combination or the single-modality vaccines were not effectively protected. These results suggest that a recombinant M. bovis BCG-based vector may have potential as an HIV/AIDS vaccine when administered in combination with a replication-deficient vaccinia virus DIs vector in a priming-boosting strategy.

E3L and F1L Gene Functions Modulate the Protective Capacity of Modified Vaccinia Virus Ankara Immunization in Murine Model of Human Smallpox.

PubMed

Volz, Asisa; Jany, Sylvia; Freudenstein, Astrid; Lantermann, Markus; Ludwig, Holger; Sutter, Gerd

2018-01-04

The highly attenuated Modified Vaccinia virus Ankara (MVA) lacks most of the known vaccinia virus (VACV) virulence and immune evasion genes. Today MVA can serve as a safety-tested next-generation smallpox vaccine. Yet, we still need to learn about regulatory gene functions preserved in the MVA genome, such as the apoptosis inhibitor genes F1L and E3L . Here, we tested MVA vaccine preparations on the basis of the deletion mutant viruses MVA-ΔF1L and MVA-ΔE3L for efficacy against ectromelia virus (ECTV) challenge infections in mice. In non-permissive human tissue culture the MVA deletion mutant viruses produced reduced levels of the VACV envelope antigen B5. Upon mousepox challenge at three weeks after vaccination, MVA-ΔF1L and MVA-ΔE3L exhibited reduced protective capacity in comparison to wildtype MVA. Surprisingly, however, all vaccines proved equally protective against a lethal ECTV infection at two days after vaccination. Accordingly, the deletion mutant MVA vaccines induced high levels of virus-specific CD8+ T cells previously shown to be essential for rapidly protective MVA vaccination. These results suggest that inactivation of the anti-apoptotic genes F1L or E3L modulates the protective capacity of MVA vaccination most likely through the induction of distinct orthopoxvirus specific immunity in the absence of these viral regulatory proteins.

Comparative Proteomics of Human Monkeypox and Vaccinia Intracellular Mature and Extracellular Enveloped Virions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manes, Nathan P.; Estep, Ryan D.; Mottaz, Heather M.

2008-03-07

Orthopoxviruses are the largest and most complex of the animal viruses. In response to the recent emergence of monkeypox in Africa and the threat of smallpox bioterrorism, virulent (monkeypox virus) and benign (vaccinia virus) orthopoxviruses were proteomically compared with the goal of identifying proteins required for pathogenesis. Orthopoxviruses were grown in HeLa cells to two different viral forms (intracellular mature virus and extracellular enveloped virus), purified by sucrose gradient ultracentrifugation, denatured using RapiGest™ surfactant, and digested with trypsin. Unfractionated samples and strong cation exchange HPLC fractions were analyzed by reversed-phase LC-MS/MS, and analyses of the MS/MS spectra using SEQUEST® andmore » X! Tandem resulted in the identification of hundreds of monkeypox, vaccinia, and copurified host proteins. The unfractionated samples were additionally analyzed by LC-MS on an LTQ-Orbitrap™, and the accurate mass and elution time tag approach was used to perform quantitative comparisons. Possible pathophysiological roles of differentially expressed orthopoxvirus genes are discussed.« less

Archaeal viruses at the cell envelope: entry and egress

PubMed Central

Quemin, Emmanuelle R. J.; Quax, Tessa E. F.

2015-01-01

The cell envelope represents the main line of host defense that viruses encounter on their way from one cell to another. The cytoplasmic membrane in general is a physical barrier that needs to be crossed both upon viral entry and exit. Therefore, viruses from the three domains of life employ a wide range of strategies for perforation of the cell membrane, each adapted to the cell surface environment of their host. Here, we review recent insights on entry and egress mechanisms of viruses infecting archaea. Due to the unique nature of the archaeal cell envelope, these particular viruses exhibit novel and unexpected mechanisms to traverse the cellular membrane. PMID:26097469

Single-virus fusion experiments reveal proton influx into vaccinia virions and hemifusion lag times.

PubMed

Schmidt, Florian I; Kuhn, Phillip; Robinson, Tom; Mercer, Jason; Dittrich, Petra S

2013-07-16

Recent studies have revealed new insights into the endocytosis of vaccinia virus (VACV). However, the mechanism of fusion between viral and cellular membranes remains unknown. We developed a microfluidic device with a cell-trap array for immobilization of individual cells, with which we analyzed the acid-dependent fusion of single virions. VACV particles incorporating enhanced green fluorescent protein (EGFP) and labeled with self-quenching concentrations of R18 membrane dye were used in combination with total internal reflection fluorescence microscopy to measure the kinetics of R18 dequenching and thus single hemifusion events initiated by a fast low-pH trigger. These studies revealed unexpectedly long lag phases between pH change and hemifusion. In addition, we found that EGFP fluorescence in the virus was quenched upon acidification, indicating that protons could access the virus core, possibly through a proton channel. In a fraction of virus particles, EGFP fluorescence was recovered, presumably after fusion-pore formation and exposure of the core to the physiological pH of the host-cell cytosol. Given that virus-encoded cation channels play a crucial role in the life cycle of many viruses and can serve as antiviral drug targets, further investigations into a potential VACV viroporin are justified. Our findings indicate that the microfluidic device described may be highly beneficial to similar studies requiring fast kinetic measurements. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

[Experiments on disinfection of vaccinia virus embedded in scabs and/or at the hand].

PubMed

Schümann, K; Grossgebauer, K

1977-01-01

Vaccinia viruses embedded in rabbit dermal scabs were subjected to physical and chemical disinfection procedures. Scabs were suspended in vitro without saline or in physiological saline, and left for 1 hour at 70 to 90 degrees C. A complete inactivation was achived only in those scab samples which had been incubated at 90 degrees C for 1 hour and suspended in physiological saline. Scabs which had been placed in a disinfecting apparatus (Vacudes 4000) filled with mattrasses consistently proved to be free of infectious vaccinia viruses in each of the chosen programs. In addition scabs were subjected to disinfection by means of chemical disinfecting agents. The scabs had been placed in a chemical disinfecting suspension and left there for 90 minutes. Complete disinfection was obtained with glutaraldehyde 2%, formaldehyde 2%, Lysoformin 2% or 3%, phenol 5% and chloramine T 2%. Complete disinfection was likewise achieved after 3 hours treatment with some alchohols (ethylalcohol 80%, isopropylalcohol 7%, n-propylalcohol 60%), Amocid 5% and formaldehyde 1%.0.5% formaldehyde caused complete disinfection when applied for 6 hours. The only exception was a Quat which did not disinfect fully even after 18 hours application. Concerning the tests to disinfect the hands complete disinfection occurs when using chloramine T (1.5%) or isopropylalcohol (70%) in 2 to 5 minutes. Further tests were performed with scabs which were placed in sick rooms that were terminally disinfected with formaline vapor. It could be confirmed that the usual terminal disinfection with formaldehyde vapor was unable to completely disinfect the scabs. It is necessary to double the amount of formaldehyde (10 g formaldehyde per cubic metre of space) and prolong the period of treatment to 24 hours to achieve a greater degree of disinfection rate.

Novel Small Molecule Entry Inhibitors of Ebola Virus

PubMed Central

Basu, Arnab; Mills, Debra M.; Mitchell, Daniel; Ndungo, Esther; Williams, John D.; Herbert, Andrew S.; Dye, John M.; Moir, Donald T.; Chandran, Kartik; Patterson, Jean L.; Rong, Lijun; Bowlin, Terry L.

2015-01-01

Background. The current Ebola virus (EBOV) outbreak has highlighted the troubling absence of available antivirals or vaccines to treat infected patients and stop the spread of EBOV. The EBOV glycoprotein (GP) plays critical roles in the early stage of virus infection, including receptor binding and membrane fusion, making it a potential target for the development of anti-EBOV drugs. We report the identification of 2 novel EBOV inhibitors targeting viral entry. Methods. To identify small molecule inhibitors of EBOV entry, we carried out a cell-based high-throughput screening using human immunodeficiency virus–based pseudotyped viruses expressing EBOV-GP. Two compounds were identified, and mechanism-of-action studies were performed using immunoflourescence, AlphaLISA, and enzymatic assays for cathepsin B inhibition. Results. We report the identification of 2 novel entry inhibitors. These inhibitors (1) inhibit EBOV infection (50% inhibitory concentration, approximately 0.28 and approximately 10 µmol/L) at a late stage of entry, (2) induce Niemann-Pick C phenotype, and (3) inhibit GP–Niemann-Pick C1 (NPC1) protein interaction. Conclusions. We have identified 2 novel EBOV inhibitors, MBX2254 and MBX2270, that can serve as starting points for the development of an anti-EBOV therapeutic agent. Our findings also highlight the importance of NPC1-GP interaction in EBOV entry and the attractiveness of NPC1 as an antifiloviral therapeutic target. PMID:26206510

Endoplasmic Reticulum-Golgi Intermediate Compartment Membranes and Vimentin Filaments Participate in Vaccinia Virus Assembly

PubMed Central

Risco, Cristina; Rodríguez, Juan R.; López-Iglesias, Carmen; Carrascosa, José L.; Esteban, Mariano; Rodríguez, Dolores

2002-01-01

Vaccinia virus (VV) has a complex morphogenetic pathway whose first steps are poorly characterized. We have studied the early phase of VV assembly, when viral factories and spherical immature viruses (IVs) form in the cytoplasm of the infected cell. After freeze-substitution numerous cellular elements are detected around assembling viruses: membranes, ribosomes, microtubules, filaments, and unidentified structures. A double membrane is clearly resolved in the VV envelope for the first time, and freeze fracture reveals groups of tubules interacting laterally on the surface of the viroplasm foci. These data strongly support the hypothesis of a cellular tubulovesicular compartment, related to the endoplasmic reticulum-Golgi intermediate compartment (ERGIC), as the origin of the first VV envelope. Moreover, the cytoskeletal vimentin intermediate filaments are found around viral factories and inside the viroplasm foci, where vimentin and the VV core protein p39 colocalize in the areas where crescents protrude. Confocal microscopy showed that ERGIC elements and vimentin filaments concentrate in the viral factories. We propose that modified cellular ERGIC membranes and vimentin intermediate filaments act coordinately in the construction of viral factories and the first VV form through a unique mechanism of viral morphogenesis from cellular elements. PMID:11799179

Antibodies to the A27 protein of vaccinia virus neutralize and protect against infection but represent a minor component of Dryvax vaccine--induced immunity.

PubMed

He, Yong; Manischewitz, Jody; Meseda, Clement A; Merchlinsky, Michael; Vassell, Russell A; Sirota, Lev; Berkower, Ira; Golding, Hana; Weiss, Carol D

2007-10-01

The smallpox vaccine Dryvax, which consists of replication-competent vaccinia virus, elicits antibodies that play a major role in protection. Several vaccinia proteins generate neutralizing antibodies, but their importance for protection is unknown. We investigated the potency of antibodies to the A27 protein of the mature virion in neutralization and protection experiments and the contributions of A27 antibodies to Dryvax-induced immunity. Using a recombinant A27 protein (rA27), we confirmed that A27 contains neutralizing determinants and that vaccinia immune globulin (VIG) derived from Dryvax recipients contains reactivity to A27. However, VIG neutralization was not significantly reduced when A27 antibodies were removed, and antibodies elicited by an rA27 enhanced the protection conferred by VIG in passive transfer experiments. These findings demonstrate that A27 antibodies do not represent the major fraction of neutralizing activity in VIG and suggest that immunity may be augmented by vaccines and immune globulins that include strong antibody responses to A27.

Molecular characterization of the host defense activity of the barrier to autointegration factor against vaccinia virus.

PubMed

Ibrahim, Nouhou; Wicklund, April; Wiebe, Matthew S

2011-11-01

The barrier to autointegration factor (BAF) is an essential cellular protein with functions in mitotic nuclear reassembly, retroviral preintegration complex stability, and transcriptional regulation. Molecular properties of BAF include the ability to bind double-stranded DNA in a sequence-independent manner, homodimerize, and bind proteins containing a LEM domain. These capabilities allow BAF to compact DNA and assemble higher-order nucleoprotein complexes, the nature of which is poorly understood. Recently, it was revealed that BAF also acts as a potent host defense against poxviral DNA replication in the cytoplasm. Here, we extend these observations by examining the molecular mechanism through which BAF acts as a host defense against vaccinia virus replication and cytoplasmic DNA in general. Interestingly, BAF rapidly relocalizes to transfected DNA from a variety of sources, demonstrating that BAF's activity as a host defense factor is not limited to poxviral infection. BAF's relocalization to cytoplasmic foreign DNA is highly dependent upon its DNA binding and dimerization properties but does not appear to require its LEM domain binding activity. However, the LEM domain protein emerin is recruited to cytoplasmic DNA in a BAF-dependent manner during both transfection and vaccinia virus infection. Finally, we demonstrate that the DNA binding and dimerization capabilities of BAF are essential for its function as an antipoxviral effector, while the presence of emerin is not required. Together, these data provide further mechanistic insight into which of BAF's molecular properties are employed by cells to impair the replication of poxviruses or respond to foreign DNA in general.

Statistical Approach To Estimate Vaccinia-Specific Neutralizing Antibody Titers Using a High-Throughput Assay▿

PubMed Central

Kennedy, Richard; Pankratz, V. Shane; Swanson, Eric; Watson, David; Golding, Hana; Poland, Gregory A.

2009-01-01

Because of the bioterrorism threat posed by agents such as variola virus, considerable time, resources, and effort have been devoted to biodefense preparation. One avenue of this research has been the development of rapid, sensitive, high-throughput assays to validate immune responses to poxviruses. Here we describe the adaptation of a β-galactosidase reporter-based vaccinia virus neutralization assay to large-scale use in a study that included over 1,000 subjects. We also describe the statistical methods involved in analyzing the large quantity of data generated. The assay and its associated methods should prove useful tools in monitoring immune responses to next-generation smallpox vaccines, studying poxvirus immunity, and evaluating therapeutic agents such as vaccinia virus immune globulin. PMID:19535540

42 CFR 102.21 - Smallpox (Vaccinia) Vaccine Injury Table.

Code of Federal Regulations, 2012 CFR

2012-10-01

... of the Table, an autoimmune central nervous system injury. In rare cases, the vaccinia virus is isolated from the central nervous system. Manifestations usually occur abruptly and may include fever... spinal cord (myelitis) such as paralysis or meningismus. Long term central nervous system impairments...

42 CFR 102.21 - Smallpox (Vaccinia) Vaccine Injury Table.

Code of Federal Regulations, 2013 CFR

2013-10-01

... of the Table, an autoimmune central nervous system injury. In rare cases, the vaccinia virus is isolated from the central nervous system. Manifestations usually occur abruptly and may include fever... spinal cord (myelitis) such as paralysis or meningismus. Long term central nervous system impairments...

42 CFR 102.21 - Smallpox (Vaccinia) Vaccine Injury Table.

Code of Federal Regulations, 2011 CFR

2011-10-01

... of the Table, an autoimmune central nervous system injury. In rare cases, the vaccinia virus is isolated from the central nervous system. Manifestations usually occur abruptly and may include fever... spinal cord (myelitis) such as paralysis or meningismus. Long term central nervous system impairments...

42 CFR 102.21 - Smallpox (Vaccinia) Vaccine Injury Table.

Code of Federal Regulations, 2014 CFR

2014-10-01

... of the Table, an autoimmune central nervous system injury. In rare cases, the vaccinia virus is isolated from the central nervous system. Manifestations usually occur abruptly and may include fever... spinal cord (myelitis) such as paralysis or meningismus. Long term central nervous system impairments...

Biophysical analysis of bacterial and viral systems. A shock tube study of bio-aerosols and a correlated AFM/nanosims investigation of vaccinia virus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gates, Sean Damien

2013-05-01

The work presented herein is concerned with the development of biophysical methodology designed to address pertinent questions regarding the behavior and structure of select pathogenic agents. Two distinct studies are documented: a shock tube analysis of endospore-laden bio-aerosols and a correlated AFM/NanoSIMS study of the structure of vaccinia virus.

Evaluation of radiation effects against C6 glioma in combination with vaccinia virus-p53 gene therapy

NASA Technical Reports Server (NTRS)

Gridley, D. S.; Andres, M. L.; Li, J.; Timiryasova, T.; Chen, B.; Fodor, I.; Nelson, G. A. (Principal Investigator)

1998-01-01

The primary objective of this study was to evaluate the antitumor effects of recombinant vaccinia virus-p53 (rVV-p53) in combination with radiation therapy against the C6 rat glioma, a p53 deficient tumor that is relatively radioresistant. VV-LIVP, the parental virus (Lister strain), was used as a control. Localized treatment of subcutaneous C6 tumors in athymic mice with either rVV-p53 or VV-LIVP together with tumor irradiation resulted in low tumor incidence and significantly slower tumor progression compared to the agents given as single modalities. Assays of blood and spleen indicated that immune system activation may account, at least partly, for the enhance tumor inhibition seen with combined treatment. No overt signs of treatment-related toxicity were noted.

Expression of the highly conserved vaccinia virus E6 protein is required for virion morphogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Resch, Wolfgang; Weisberg, Andrea S.; Moss, Bernard, E-mail: bmoss@nih.go

2009-04-10

The vaccinia virus E6R gene (VACVWR062) is conserved in all members of the poxvirus family and encodes a protein associated with the mature virion. We confirmed this association and provided evidence for an internal location. An inducible mutant that conditionally expresses E6 was constructed. In the absence of inducer, plaque formation and virus production were severely inhibited in several cell lines, whereas some replication occurred in others. This difference could be due to variation in the stringency of repression, since we could not isolate a stable deletion mutant even in the more 'permissive' cells. Under non-permissive conditions, viral late proteinsmore » were synthesized but processing of core proteins was inefficient, indicative of an assembly block. Transmission electron microscopy of sections of cells infected with the mutant in the absence of inducer revealed morphogenetic defects with crescents and empty immature virions adjacent to dense inclusions of viroplasm. Mature virions were infrequent and cores appeared to have lucent centers.« less

Mediators and mechanisms of herpes simplex virus entry into ocular cells.

PubMed

Farooq, Asim V; Valyi-Nagy, Tibor; Shukla, Deepak

2010-06-01

The entry of herpes simplex virus into cells was once thought to be a general process. It is now understood that the virus is able to use multiple mechanisms for entry and spread, including the use of receptors and co-receptors that have been determined to be cell-type specific. This is certainly true for ocular cell types, which is important as the virus may use different mechanisms to gain access to multiple anatomic structures in close proximity, leading to various ocular diseases. There are some patterns that may be utilized by the virus in the eye and elsewhere, including surfing along filopodia in moving from cell to cell. There are common themes as well as intriguing differences in the entry mechanisms of herpes simplex virus into ocular cells. We discuss these issues in the context of conjunctivitis, keratitis, acute retinal necrosis, and other ocular diseases.

Multisubunit DNA-Dependent RNA Polymerases from Vaccinia Virus and Other Nucleocytoplasmic Large-DNA Viruses: Impressions from the Age of Structure.

PubMed

Mirzakhanyan, Yeva; Gershon, Paul D

2017-09-01

The past 17 years have been marked by a revolution in our understanding of cellular multisubunit DNA-dependent RNA polymerases (MSDDRPs) at the structural level. A parallel development over the past 15 years has been the emerging story of the giant viruses, which encode MSDDRPs. Here we link the two in an attempt to understand the specialization of multisubunit RNA polymerases in the domain of life encompassing the large nucleocytoplasmic DNA viruses (NCLDV), a superclade that includes the giant viruses and the biochemically well-characterized poxvirus vaccinia virus. The first half of this review surveys the recently determined structural biology of cellular RNA polymerases for a microbiology readership. The second half discusses a reannotation of MSDDRP subunits from NCLDV families and the apparent specialization of these enzymes by virus family and by subunit with regard to subunit or domain loss, subunit dissociability, endogenous control of polymerase arrest, and the elimination/customization of regulatory interactions that would confer higher-order cellular control. Some themes are apparent in linking subunit function to structure in the viral world: as with cellular RNA polymerases I and III and unlike cellular RNA polymerase II, the viral enzymes seem to opt for speed and processivity and seem to have eliminated domains associated with higher-order regulation. The adoption/loss of viral RNA polymerase proofreading functions may have played a part in matching intrinsic mutability to genome size. Copyright © 2017 American Society for Microbiology.

Structural and mechanistic studies of measles virus illuminate paramyxovirus entry.

PubMed

Plemper, Richard K; Brindley, Melinda A; Iorio, Ronald M

2011-06-01

Measles virus (MeV), a member of the paramyxovirus family of enveloped RNA viruses and one of the most infectious viral pathogens identified, accounts for major pediatric morbidity and mortality worldwide although coordinated efforts to achieve global measles control are in place. Target cell entry is mediated by two viral envelope glycoproteins, the attachment (H) and fusion (F) proteins, which form a complex that achieves merger of the envelope with target cell membranes. Despite continually expanding knowledge of the entry strategies employed by enveloped viruses, our molecular insight into the organization of functional paramyxovirus fusion complexes and the mechanisms by which the receptor binding by the attachment protein triggers the required conformational rearrangements of the fusion protein remain incomplete. Recently reported crystal structures of the MeV attachment protein in complex with its cellular receptors CD46 or SLAM and newly developed functional assays have now illuminated some of the fundamental principles that govern cell entry by this archetype member of the paramyxovirus family. Here, we review these advances in our molecular understanding of MeV entry in the context of diverse entry strategies employed by other members of the paramyxovirus family.

Development of a Genetically-Engineered Venezuelan Equine Encephalitis virus Vaccine

DTIC Science & Technology

1989-11-13

necrosis. We have evaluated the efficacy of a recombinant vaccinia/VEE virus vaccine (TC-5A) to protect horses against challenge with equine virulent...of horse vaccinees with equine virulent VEE virus 71-180 and vaccinia viruses ........ 27 7. ELISA cross-reactivity of sera from immunized equines ...antibodies in equines after immuniza- tion with TC-83, TC-5A and wild-type vaccinia viruses . .40 5. Body temperature of horses immunized with TC-5A (A

Identification and Characterization of a Novel Broad-Spectrum Virus Entry Inhibitor

PubMed Central

Chou, Yi-ying; Cuevas, Christian; Carocci, Margot; Stubbs, Sarah H.; Ma, Minghe; Cureton, David K.; Evesson, Frances; He, Kangmin; Yang, Priscilla L.; Whelan, Sean P.

2016-01-01

ABSTRACT Virus entry into cells is a multistep process that often requires the subversion of subcellular machineries. A more complete understanding of these steps is necessary to develop new antiviral strategies. While studying the potential role of the actin network and one of its master regulators, the small GTPase Cdc42, during Junin virus (JUNV) entry, we serendipitously uncovered the small molecule ZCL278, reported to inhibit Cdc42 function as an entry inhibitor for JUNV and for vesicular stomatitis virus, lymphocytic choriomeningitis virus, and dengue virus but not for the nonenveloped poliovirus. Although ZCL278 did not interfere with JUNV attachment to the cell surface or virus particle internalization into host cells, it prevented the release of JUNV ribonucleoprotein cores into the cytosol and decreased pH-mediated viral fusion with host membranes. We also identified SVG-A astroglial cell-derived cells to be highly permissive for JUNV infection and generated new cell lines expressing fluorescently tagged Rab5c or Rab7a or lacking Cdc42 using clustered regularly interspaced short palindromic repeat (CRISPR)-caspase 9 (Cas9) gene-editing strategies. Aided by these tools, we uncovered that perturbations in the actin cytoskeleton or Cdc42 activity minimally affect JUNV entry, suggesting that the inhibitory effect of ZCL278 is not mediated by ZCL278 interfering with the activity of Cdc42. Instead, ZCL278 appears to redistribute viral particles from endosomal to lysosomal compartments. ZCL278 also inhibited JUNV replication in a mouse model, and no toxicity was detected. Together, our data suggest the unexpected antiviral activity of ZCL278 and highlight its potential for use in the development of valuable new tools to study the intracellular trafficking of pathogens. IMPORTANCE The Junin virus is responsible for outbreaks of Argentine hemorrhagic fever in South America, where 5 million people are at risk. Limited options are currently available to treat

Mediators and Mechanisms of Herpes Simplex Virus Entry into Ocular Cells

PubMed Central

Farooq, Asim V.; Valyi-Nagy, Tibor; Shukla, Deepak

2010-01-01

The entry of herpes simplex virus (HSV) into cells was once thought to be a general process. It is now understood that the virus is able to use multiple mechanisms for entry and spread, including the use of receptors and co-receptors that have been determined to be cell-type specific. This is certainly true for ocular cell types, which is important as the virus may use different mechanisms to gain access to multiple anatomic structures in close proximity, leading to various ocular diseases. There are some patterns that may be utilized by the virus in the eye and elsewhere, including surfing along filopodia in moving from cell to cell. There are common themes as well as intriguing differences in the entry mechanisms of HSV into ocular cells. We discuss these issues in the context of conjunctivitis, keratitis, acute retinal necrosis and other ocular diseases. PMID:20465436

Major neutralizing sites on vaccinia virus glycoprotein B5 are exposed differently on variola virus ortholog B6.

PubMed

Aldaz-Carroll, Lydia; Xiao, Yuhong; Whitbeck, J Charles; de Leon, Manuel Ponce; Lou, Huan; Kim, Mikyung; Yu, Jessica; Reinherz, Ellis L; Isaacs, Stuart N; Eisenberg, Roselyn J; Cohen, Gary H

2007-08-01

Immunization against smallpox (variola virus) with Dryvax, a live vaccinia virus (VV), was effective, but now safety is a major concern. To overcome this issue, subunit vaccines composed of VV envelope proteins from both forms of infectious virions, including the extracellular enveloped virion (EV) protein B5, are being developed. However, since B5 has 23 amino acid differences compared with its B6 variola virus homologue, B6 might be a better choice for such a strategy. Therefore, we compared the properties of both proteins using a panel of monoclonal antibodies (MAbs) to B5 that we had previously characterized and grouped according to structural and functional properties. The B6 gene was obtained from the Centers for Disease Control and Prevention, and the ectodomain was cloned and expressed in baculovirus as previously done with B5, allowing us to compare the antigenic properties of the proteins. Polyclonal antibodies to B5 or B6 cross-reacted with the heterologous protein, and 16 of 26 anti-B5 MAbs cross-reacted with B6. Importantly, 10 anti-B5 MAbs did not cross-react with B6. Of these, three have important anti-VV biologic properties, including their ability to neutralize EV infectivity and block comet formation. Here, we found that one of these three MAbs protected mice from a lethal VV challenge by passive immunization. Thus, epitopes that are present on B5 but not on B6 would generate an antibody response that would not recognize B6. Assuming that B6 contains similar variola virus-specific epitopes, our data suggest that a subunit vaccine using the variola virus homologues might exhibit improved protective efficacy against smallpox.

Mutagenic repair of double-stranded DNA breaks in vaccinia virus genomes requires cellular DNA ligase IV activity in the cytosol.

PubMed

Luteijn, Rutger David; Drexler, Ingo; Smith, Geoffrey L; Lebbink, Robert Jan; Wiertz, Emmanuel J H J

2018-06-01

Poxviruses comprise a group of large dsDNA viruses that include members relevant to human and animal health, such as variola virus, monkeypox virus, cowpox virus and vaccinia virus (VACV). Poxviruses are remarkable for their unique replication cycle, which is restricted to the cytoplasm of infected cells. The independence from the host nucleus requires poxviruses to encode most of the enzymes involved in DNA replication, transcription and processing. Here, we use the CRISPR/Cas9 genome engineering system to induce DNA damage to VACV (strain Western Reserve) genomes. We show that targeting CRISPR/Cas9 to essential viral genes limits virus replication efficiently. Although VACV is a strictly cytoplasmic pathogen, we observed extensive viral genome editing at the target site; this is reminiscent of a non-homologous end-joining DNA repair mechanism. This pathway was not dependent on the viral DNA ligase, but critically involved the cellular DNA ligase IV. Our data show that DNA ligase IV can act outside of the nucleus to allow repair of dsDNA breaks in poxvirus genomes. This pathway might contribute to the introduction of mutations within the genome of poxviruses and may thereby promote the evolution of these viruses.

Involvement of Clathrin-Mediated Endocytosis in Human Immunodeficiency Virus Type 1 Entry

PubMed Central

Daecke, Jessica; Fackler, Oliver T.; Dittmar, Matthias T.; Kräusslich, Hans-Georg

2005-01-01

Productive entry of human immunodeficiency virus (HIV) is believed to occur by direct fusion at the plasma membrane. Endocytic uptake of HIV particles has been observed in several studies but is considered to be nonproductive, leading to virus degradation in the lysosome. We show here that endocytosis contributes significantly to productive HIV entry in HeLa cells by using trans dominant-negative mutants of dynamin and Eps15. Inducible expression of a dominant-negative mutant of dynamin in a CD4-positive HeLa cell line reduced HIV infection by 40 to 80%. This effect was independent of the infectious dose and was observed for three different isolates. Analysis of reverse transcription products by real-time PCR and of virus entry by delivery of a virion-associated Vpr-β-lactamase fusion protein revealed a similar reduction, indicating that the block occurred at the entry stage. A strong reduction of HIV entry was also observed upon transient transfection of a different trans dominant-negative variant of dynamin, and this reduction correlated with the relative inhibition of transferrin endocytosis. Expression of a dominant-negative variant of Eps15, which is specific for clathrin-dependent endocytosis, reduced HIV entry in HeLa cells by ca 95%, confirming the role of endocytosis for productive infection. In contrast, no effect was observed for a dominant-negative variant of caveolin. We conclude that dynamin-dependent, clathrin-mediated endocytosis can lead to productive entry of HIV in HeLa cells, suggesting this pathway as an alternative route of virus entry. PMID:15650184

Intratumoral delivery of inactivated modified vaccinia virus Ankara (iMVA) induces systemic antitumor immunity via STING and Batf3-dependent dendritic cells.

PubMed

Dai, Peihong; Wang, Weiyi; Yang, Ning; Serna-Tamayo, Cristian; Ricca, Jacob M; Zamarin, Dmitriy; Shuman, Stewart; Merghoub, Taha; Wolchok, Jedd D; Deng, Liang

2017-05-19

Advanced cancers remain a therapeutic challenge despite recent progress in targeted therapy and immunotherapy. Novel approaches are needed to alter the tumor immunosuppressive microenvironment and to facilitate the recognition of tumor antigens that leads to antitumor immunity. Poxviruses, such as modified vaccinia virus Ankara (MVA), have potential as immunotherapeutic agents. We show that infection of conventional dendritic cells (DCs) with heat- or ultraviolet-inactivated MVA leads to higher levels of interferon induction than MVA alone through the cGAS (cyclic guanosine monophosphate-adenosine monophosphate synthase)-STING cytosolic DNA-sensing pathway. Intratumoral injection of inactivated MVA (iMVA) was effective and generated adaptive antitumor immunity in murine melanoma and colon cancer models. iMVA-induced antitumor therapy was less effective in STING- or Batf3-deficient mice than in wild-type mice, indicating that both cytosolic DNA sensing and Batf3-dependent CD103 + /CD8α + DCs are essential for iMVA immunotherapy. The combination of intratumoral delivery of iMVA and systemic delivery of immune checkpoint blockade generated synergistic antitumor effects in bilateral tumor implantation models as well as in a unilateral large established tumor model. Our results suggest that inactivated vaccinia virus could be used as an immunotherapeutic agent for human cancers. Copyright © 2017, American Association for the Advancement of Science.

RAB1A promotes Vaccinia virus replication by facilitating the production of intracellular enveloped virions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pechenick Jowers, Tali; Featherstone, Rebecca J.; Reynolds, Danielle K.

2015-01-15

Vaccinia virus (VACV) is a large double-stranded DNA virus with a complex cytoplasmic replication cycle that exploits numerous cellular proteins. This work characterises the role of a proviral cellular protein, the small GTPase RAB1A, in VACV replication. Using siRNA, we identified RAB1A as required for the production of extracellular enveloped virions (EEVs), but not intracellular mature virions (IMVs). Immunofluorescence and electron microscopy further refined the role of RAB1A as facilitating the wrapping of IMVs to become intracellular enveloped virions (IEVs). This is consistent with the known function of RAB1A in maintenance of ER to Golgi transport. VACV can therefore bemore » added to the growing list of viruses which require RAB1A for optimal replication, highlighting this protein as a broadly proviral host factor. - Highlights: • Characterisation of the role of the small GTPase RAB1A in VACV replication. • RAB1A is not required for production of the primary virion form (IMV). • RAB1A is required for production of processed virion forms (IEVs, CEVs and EEVs). • Consistent with known role of RAB1A in ER to Golgi transport.« less

Vaccination with recombinant modified vaccinia virus Ankara prevents the onset of intestinal allergy in mice.

PubMed

Bohnen, C; Wangorsch, A; Schülke, S; Nakajima-Adachi, H; Hachimura, S; Burggraf, M; Süzer, Y; Schwantes, A; Sutter, G; Waibler, Z; Reese, G; Toda, M; Scheurer, S; Vieths, S

2013-08-01

Modified vaccinia virus Ankara (MVA)-encoding antigens are considered as safe vaccine candidates for various infectious diseases in humans. Here, we investigated the immune-modulating properties of MVA-encoding ovalbumin (MVA-OVA) on the allergen-specific immune response. The immune-modulating properties of MVA-OVA were investigated using GM-CSF-differentiated BMDCs from C57BL/6 mice. OVA expression upon MVA-OVA infection of BMDCs was monitored. Activation and maturation markers on viable MVA-OVA-infected mDCs were analyzed by flow cytometry. Secretion of INF-γ, IL-2, and IL-10 was determined in a co-culture of BMDCs infected with wtMVA or MVA-OVA and OVA-specific OT-I CD8(+) and OT-II CD4(+ ) T cells. BALB/c mice were vaccinated with wtMVA, MVA-OVA, or PBS, sensitized to OVA/alum and challenged with a diet containing chicken egg white. OVA-specific IgE, IgG1, and IgG2a and cytokine secretion from mesenteric lymph node (MLN) cells were analyzed. Body weight, body temperature, food uptake, intestinal inflammation, and health condition of mice were monitored. Infection with wtMVA and MVA-OVA induced comparable activation of mDCs. MVA-OVA-infected BMDCs expressed OVA and induced enhanced IFN-γ and IL-2 secretion from OVA-specific CD8(+ ) T cells in comparison with OVA, wtMVA, or OVA plus wtMVA. Prophylactic vaccination with MVA-OVA significantly repressed OVA-specific IgE, whereas OVA-specific IgG2a was induced. MVA-OVA vaccination suppressed TH 2 cytokine production in MLN cells and prevented the onset of allergic symptoms and inflammation in a mouse model of OVA-induced intestinal allergy. Modified vaccinia virus Ankara-ovalbumin (MVA-OVA) vaccination induces a strong OVA-specific TH 1- immune response, likely mediated by the induction of IFN-γ and IgG2a. Finally, MVA-based vaccines need to be evaluated for their therapeutic potential in established allergy models. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Adverse Events Post Smallpox-Vaccination: Insights from Tail Scarification Infection in Mice with Vaccinia virus

PubMed Central

Mota, Bruno E. F.; Gallardo-Romero, Nadia; Trindade, Giliane; Keckler, M. Shannon; Karem, Kevin; Carroll, Darin; Campos, Marco A.; Vieira, Leda Q.; da Fonseca, Flávio G.; Ferreira, Paulo C. P.; Bonjardim, Cláudio A.; Damon, Inger K.; Kroon, Erna G.

2011-01-01

Adverse events upon smallpox vaccination with fully-replicative strains of Vaccinia virus (VACV) comprise an array of clinical manifestations that occur primarily in immunocompromised patients leading to significant host morbidity/mortality. The expansion of immune-suppressed populations and the possible release of Variola virus as a bioterrorist act have given rise to concerns over vaccination complications should more widespread vaccination be reinitiated. Our goal was to evaluate the components of the host immune system that are sufficient to prevent morbidity/mortality in a murine model of tail scarification, which mimics immunological and clinical features of smallpox vaccination in humans. Infection of C57BL/6 wild-type mice led to a strictly localized infection, with complete viral clearance by day 28 p.i. On the other hand, infection of T and B-cell deficient mice (Rag1 −/−) produced a severe disease, with uncontrolled viral replication at the inoculation site and dissemination to internal organs. Infection of B-cell deficient animals (µMT) produced no mortality. However, viral clearance in µMT animals was delayed compared to WT animals, with detectable viral titers in tail and internal organs late in infection. Treatment of Rag1 −/− with rabbit hyperimmune anti-vaccinia serum had a subtle effect on the morbidity/mortality of this strain, but it was effective in reduce viral titers in ovaries. Finally, NUDE athymic mice showed a similar outcome of infection as Rag1 −/−, and passive transfer of WT T cells to Rag1 −/− animals proved fully effective in preventing morbidity/mortality. These results strongly suggest that both T and B cells are important in the immune response to primary VACV infection in mice, and that T-cells are required to control the infection at the inoculation site and providing help for B-cells to produce antibodies, which help to prevent viral dissemination. These insights might prove helpful to better identify

Adverse events post smallpox-vaccination: insights from tail scarification infection in mice with Vaccinia virus.

PubMed

Mota, Bruno E F; Gallardo-Romero, Nadia; Trindade, Giliane; Keckler, M Shannon; Karem, Kevin; Carroll, Darin; Campos, Marco A; Vieira, Leda Q; da Fonseca, Flávio G; Ferreira, Paulo C P; Bonjardim, Cláudio A; Damon, Inger K; Kroon, Erna G

2011-04-15

Adverse events upon smallpox vaccination with fully-replicative strains of Vaccinia virus (VACV) comprise an array of clinical manifestations that occur primarily in immunocompromised patients leading to significant host morbidity/mortality. The expansion of immune-suppressed populations and the possible release of Variola virus as a bioterrorist act have given rise to concerns over vaccination complications should more widespread vaccination be reinitiated. Our goal was to evaluate the components of the host immune system that are sufficient to prevent morbidity/mortality in a murine model of tail scarification, which mimics immunological and clinical features of smallpox vaccination in humans. Infection of C57BL/6 wild-type mice led to a strictly localized infection, with complete viral clearance by day 28 p.i. On the other hand, infection of T and B-cell deficient mice (Rag1(-/-)) produced a severe disease, with uncontrolled viral replication at the inoculation site and dissemination to internal organs. Infection of B-cell deficient animals (µMT) produced no mortality. However, viral clearance in µMT animals was delayed compared to WT animals, with detectable viral titers in tail and internal organs late in infection. Treatment of Rag1(-/-) with rabbit hyperimmune anti-vaccinia serum had a subtle effect on the morbidity/mortality of this strain, but it was effective in reduce viral titers in ovaries. Finally, NUDE athymic mice showed a similar outcome of infection as Rag1(-/-), and passive transfer of WT T cells to Rag1(-/-) animals proved fully effective in preventing morbidity/mortality. These results strongly suggest that both T and B cells are important in the immune response to primary VACV infection in mice, and that T-cells are required to control the infection at the inoculation site and providing help for B-cells to produce antibodies, which help to prevent viral dissemination. These insights might prove helpful to better identify individuals with

Polyvalent 2D Entry Inhibitors for Pseudorabies and African Swine Fever Virus.

PubMed

Ziem, Benjamin; Rahn, Jessica; Donskyi, Ievgen; Silberreis, Kim; Cuellar, Luis; Dernedde, Jens; Keil, Günther; Mettenleiter, Thomas C; Haag, Rainer

2017-06-01

African swine fever virus (ASFV) is one of the most dangerous viruses for pigs and is endemic in Africa but recently also spread into the Russian Federation and the Eastern border of the EU. So far there is no vaccine or antiviral drug available to curtail the infection. Thus, control strategies based on novel inhibitors are urgently needed. Another highly relevant virus infection in pigs is Aujeszky's disease caused by the alphaherpesvirus pseudorabies virus (PrV). This article reports the synthesis and biological evaluation of novel extracellular matrix-inspired entry inhibitors based on polyglycerol sulfate-functionalized graphene sheets. The developed 2D architectures bind enveloped viruses during the adhesion process and thereby exhibit strong inhibitory effects, which are equal or better than the common standards enrofloxacin and heparin as demonstrated for ASFV and PrV. Overall, the developed polyvalent 2D entry inhibitors are nontoxic and efficient nanoarchitectures, which interact with various types of enveloped viruses. Therefore they prevent viral adhesion to the host cell and especially target viruses that rely on a heparan sulfate-dependent cell entry mechanism. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dynamics of Chikungunya Virus Cell Entry Unraveled by Single-Virus Tracking in Living Cells.

PubMed

Hoornweg, Tabitha E; van Duijl-Richter, Mareike K S; Ayala Nuñez, Nilda V; Albulescu, Irina C; van Hemert, Martijn J; Smit, Jolanda M

2016-05-01

Chikungunya virus (CHIKV) is a rapidly emerging mosquito-borne human pathogen causing major outbreaks in Africa, Asia, and the Americas. The cell entry pathway hijacked by CHIKV to infect a cell has been studied previously using inhibitory compounds. There has been some debate on the mechanism by which CHIKV enters the cell: several studies suggest that CHIKV enters via clathrin-mediated endocytosis, while others show that it enters independently of clathrin. Here we applied live-cell microscopy and monitored the cell entry behavior of single CHIKV particles in living cells transfected with fluorescent marker proteins. This approach allowed us to obtain detailed insight into the dynamic events that occur during CHIKV entry. We observed that almost all particles fused within 20 min after addition to the cells. Of the particles that fused, the vast majority first colocalized with clathrin. The average time from initial colocalization with clathrin to the moment of membrane fusion was 1.7 min, highlighting the rapidity of the cell entry process of CHIKV. Furthermore, these results show that the virus spends a relatively long time searching for a receptor. Membrane fusion was observed predominantly from within Rab5-positive endosomes and often occurred within 40 s after delivery to endosomes. Furthermore, we confirmed that a valine at position 226 of the E1 protein enhances the cholesterol-dependent membrane fusion properties of CHIKV. To conclude, our work confirms that CHIKV enters cells via clathrin-mediated endocytosis and shows that fusion occurs from within acidic early endosomes. Since its reemergence in 2004, chikungunya virus (CHIKV) has spread rapidly around the world, leading to millions of infections. CHIKV often causes chikungunya fever, a self-limiting febrile illness with severe arthralgia. Currently, no vaccine or specific antiviral treatment against CHIKV is available. A potential antiviral strategy is to interfere with the cell entry process of the

Role of endocytosis and cathepsin-mediated activation in Nipah virus entry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diederich, Sandra; Thiel, Lena; Maisner, Andrea

The recent discovery that the Nipah virus (NiV) fusion protein (F) is activated by endosomal cathepsin L raised the question if NiV utilize pH- and protease-dependent mechanisms of entry. We show here that the NiV receptor ephrin B2, virus-like particles and infectious NiV are internalized from the cell surface. However, endocytosis, acidic pH and cathepsin-mediated cleavage are not necessary for the initiation of infection of new host cells. Our data clearly demonstrate that proteolytic activation of the NiV F protein is required before incorporation into budding virions but not after virus entry.

Major Neutralizing Sites on Vaccinia Virus Glycoprotein B5 Are Exposed Differently on Variola Virus Ortholog B6▿

PubMed Central

Aldaz-Carroll, Lydia; Xiao, Yuhong; Whitbeck, J. Charles; de Leon, Manuel Ponce; Lou, Huan; Kim, Mikyung; Yu, Jessica; Reinherz, Ellis L.; Isaacs, Stuart N.; Eisenberg, Roselyn J.; Cohen, Gary H.

2007-01-01

Immunization against smallpox (variola virus) with Dryvax, a live vaccinia virus (VV), was effective, but now safety is a major concern. To overcome this issue, subunit vaccines composed of VV envelope proteins from both forms of infectious virions, including the extracellular enveloped virion (EV) protein B5, are being developed. However, since B5 has 23 amino acid differences compared with its B6 variola virus homologue, B6 might be a better choice for such a strategy. Therefore, we compared the properties of both proteins using a panel of monoclonal antibodies (MAbs) to B5 that we had previously characterized and grouped according to structural and functional properties. The B6 gene was obtained from the Centers for Disease Control and Prevention, and the ectodomain was cloned and expressed in baculovirus as previously done with B5, allowing us to compare the antigenic properties of the proteins. Polyclonal antibodies to B5 or B6 cross-reacted with the heterologous protein, and 16 of 26 anti-B5 MAbs cross-reacted with B6. Importantly, 10 anti-B5 MAbs did not cross-react with B6. Of these, three have important anti-VV biologic properties, including their ability to neutralize EV infectivity and block comet formation. Here, we found that one of these three MAbs protected mice from a lethal VV challenge by passive immunization. Thus, epitopes that are present on B5 but not on B6 would generate an antibody response that would not recognize B6. Assuming that B6 contains similar variola virus-specific epitopes, our data suggest that a subunit vaccine using the variola virus homologues might exhibit improved protective efficacy against smallpox. PMID:17522205

Comparable polyfunctionality of ectromelia virus- and vaccinia virus-specific murine T cells despite markedly different in vivo replication and pathogenicity.

PubMed

Hersperger, Adam R; Siciliano, Nicholas A; Eisenlohr, Laurence C

2012-07-01

Vaccinia virus (VACV) stimulates long-term immunity against highly pathogenic orthopoxvirus infection of humans (smallpox) and mice (mousepox [ectromelia virus {ECTV}]) despite the lack of a natural host-pathogen relationship with either of these species. Previous research revealed that VACV is able to induce polyfunctional CD8(+) T-cell responses after immunization of humans. However, the degree to which the functional profile of T cells induced by VACV is similar to that generated during natural poxvirus infection remains unknown. In this study, we monitored virus-specific T-cell responses following the dermal infection of C57BL/6 mice with ECTV or VACV. Using polychromatic flow cytometry, we measured levels of degranulation, cytokine expression (gamma interferon [IFN-γ], tumor necrosis factor alpha [TNF-α], and interleukin-2 [IL-2]), and the cytolytic mediator granzyme B. We observed that the functional capacities of T cells induced by VACV and ECTV were of a similar quality in spite of the markedly different replication abilities and pathogenic outcomes of these viruses. In general, a significant fraction (≥50%) of all T-cell responses were positive for at least three functions both during acute infection and into the memory phase. In vivo killing assays revealed that CD8(+) T cells specific for both viruses were equally cytolytic (∼80% target cell lysis after 4 h), consistent with the similar levels of granzyme B and degranulation detected among these cells. Collectively, these data provide a mechanism to explain the ability of VACV to induce protective T-cell responses against pathogenic poxviruses in their natural hosts and provide further support for the use of VACV as a vaccine platform able to induce polyfunctional T cells.

Isolated limb perfusion with melphalan, tumour necrosis factor-alpha and oncolytic vaccinia virus improves tumour targeting and prolongs survival in a rat model of advanced extremity sarcoma.

PubMed

Pencavel, Tim D; Wilkinson, Michelle J; Mansfield, David C; Khan, Aadil A; Seth, Rohit; Karapanagiotou, Eleni M; Roulstone, Victoria; Aguilar, Richard J; Chen, Nanhai G; Szalay, Aladar A; Hayes, Andrew J; Harrington, Kevin J

2015-02-15

Isolated limb perfusion (ILP) is a treatment for advanced extremity sarcoma and in-transit melanoma. Advancing this procedure by investigating the addition of novel agents, such as cancer-selective oncolytic viruses, may improve both the therapeutic efficacy of ILP and the tumour-targeted delivery of oncolytic virotherapy. Standard in vitro assays were used to characterise single agent and combinatorial activities of melphalan, tumour necrosis factor-alpha (TNF-α) and Lister strain vaccinia virus (GLV-1h68) against BN175 rat sarcoma cells. An orthotopic model of advanced extremity sarcoma was used to evaluate survival of animals after ILP with combinations of TNF-α, melphalan and GLV-1h68. We investigated the efficiency of viral tumour delivery by ILP compared to intravenous therapy, the locoregional and systemic biodistribution of virus after ILP, and the effect of mode of administration on antibody response. The combination of melphalan and GLV-1h68 was synergistic in vitro. The addition of virus to standard ILP regimens was well tolerated and demonstrated superior tumour targeting compared to intravenous administration. Triple therapy (melphalan/TNF-α/GLV-1h68) resulted in increased tumour growth delay and enhanced survival compared to other treatment regimens. Live virus was recovered in large amounts from perfused regions, but in smaller amounts from systemic organs. The addition of oncolytic vaccinia virus to existing TNF-α/melphalan-based ILP strategies results in survival advantage in an immunocompetent rat model of advanced extremity sarcoma. Virus administered by ILP has superior tumour targeting compared to intravenous delivery. Further evaluation and clinical translation of this approach is warranted. © 2014 UICC.

Interaction of Human Tumor Viruses with Host Cell Surface Receptors and Cell Entry

PubMed Central

Schäfer, Georgia; Blumenthal, Melissa J.; Katz, Arieh A.

2015-01-01

Currently, seven viruses, namely Epstein-Barr virus (EBV), Kaposi’s sarcoma-associated herpes virus (KSHV), high-risk human papillomaviruses (HPVs), Merkel cell polyomavirus (MCPyV), hepatitis B virus (HBV), hepatitis C virus (HCV) and human T cell lymphotropic virus type 1 (HTLV-1), have been described to be consistently associated with different types of human cancer. These oncogenic viruses belong to distinct viral families, display diverse cell tropism and cause different malignancies. A key to their pathogenicity is attachment to the host cell and entry in order to replicate and complete their life cycle. Interaction with the host cell during viral entry is characterized by a sequence of events, involving viral envelope and/or capsid molecules as well as cellular entry factors that are critical in target cell recognition, thereby determining cell tropism. Most oncogenic viruses initially attach to cell surface heparan sulfate proteoglycans, followed by conformational change and transfer of the viral particle to secondary high-affinity cell- and virus-specific receptors. This review summarizes the current knowledge of the host cell surface factors and molecular mechanisms underlying oncogenic virus binding and uptake by their cognate host cell(s) with the aim to provide a concise overview of potential target molecules for prevention and/or treatment of oncogenic virus infection. PMID:26008702

Nucleotide Sequence of the Hantaan Virus S RNA Segment and Expression of Encoded Proteins

DTIC Science & Technology

1987-11-03

human vaccinia vaccination ). A second dose of virus was given in the same ...vaccinia vector. A necessary first step in vaccine investigation woul d be to determine if animals infected with the two HTV recombinant viruses can ...vaccinia virus (Buller et al., 1985). Mice were infected by tail scarification since it is identical to the method used to vaccinate 169 humans

Immunogenicity and Protection Against Influenza H7N3 in Mice by Modified Vaccinia Virus Ankara Vectors Expressing Influenza Virus Hemagglutinin or Neuraminidase.

PubMed

Meseda, Clement A; Atukorale, Vajini; Soto, Jackeline; Eichelberger, Maryna C; Gao, Jin; Wang, Wei; Weiss, Carol D; Weir, Jerry P

2018-03-29

Influenza subtypes such as H7 have pandemic potential since they are able to infect humans with severe consequences, as evidenced by the ongoing H7N9 infections in China that began in 2013. The diversity of H7 viruses calls for a broadly cross-protective vaccine for protection. We describe the construction of recombinant modified vaccinia virus Ankara (MVA) vectors expressing the hemagglutinin (HA) or neuraminidase (NA) from three H7 viruses representing both Eurasian and North American H7 lineages - A/mallard/Netherlands/12/2000 (H7N3), A/Canada/rv444/2004 (H7N3), and A/Shanghai/02/2013 (H7N9). These vectors were evaluated for immunogenicity and protective efficacy against H7N3 virus in a murine model of intranasal challenge. High levels of H7-, N3-, and N9-specific antibodies, including neutralizing antibodies, were induced by the MVA-HA and MVA-NA vectors. Mice vaccinated with MVA vectors expressing any of the H7 antigens were protected, suggesting cross-protection among H7 viruses. In addition, MVA vectors expressing N3 but not N9 elicited protection against H7N3 virus challenge. Similar outcomes were obtained when immune sera from MVA vector-immunized mice were passively transferred to naïve mice prior to challenge with the H7N3 virus. The results support the further development of an MVA vector platform as a candidate vaccine for influenza strains with pandemic potential.

The requirements for herpes simplex virus type 1 cell-cell spread via nectin-1 parallel those for virus entry.

PubMed

Even, Deborah L; Henley, Allison M; Geraghty, Robert J

2006-08-01

Herpes simplex virus type 1 (HSV-1) spreads from an infected cell to an uninfected cell by virus entry, virus-induced cell fusion, and cell-cell spread. The three forms of virus spread require the viral proteins gB, gD, and gH-gL, as well as a cellular gD receptor. The mutual requirement for the fusion glycoproteins and gD receptor suggests that virus entry, cell fusion, and cell-cell spread occur by a similar mechanism. The goals of this study were to examine the role of the nectin-1alpha transmembrane domain and cytoplasmic tail in cell-cell spread and to obtain a better understanding of the receptor-dependent events occurring at the plasma membrane during cell-cell spread. We determined that an intact nectin-1alpha V-like domain was required for cell-cell spread, while a membrane-spanning domain and cytoplasmic tail were not. Chimeric forms of nectin-1 that were non-functional for virus entry did not mediate cell-cell spread regardless of whether they could mediate cell fusion. Also, cell-cell spread of syncytial isolates was dependent upon nectin-1alpha expression and occurred through a nectin-1-dependent mechanism. Taken together, our results indicate that nectin-1-dependent events occurring at the plasma membrane during cell-cell spread were equivalent to those for virus entry.

Bovine Vaccinia: Insights into the Disease in Cattle

PubMed Central

Rehfeld, Izabelle Silva; Lobato, Zélia Inês Portela

2018-01-01

Bovine vaccinia (BV), caused by Vaccinia virus (VACV), is a zoonosis characterized by exanthematous lesions in the teats of dairy cows and the hands of milkers and is an important public health issue. Severe VACV-induced lesions in the teats and udder of cows and buffaloes could lead to mastitis and other secondary infections, thereby reducing productivity and resulting in economic losses to the dairy industry. In Brazil, BV re-emerged in the late 1990s and is now endemic in most of the Brazilian territory. In the last 15 years, much effort has been made to know more about this disease and its epidemiology, etiologic agents, and interactions with the host and the environment. In this review, we describe the known dynamics of VACV infection in cattle and the viral shedding routes, as well as the relevance of BV for animal and public health. PMID:29522489

Recombinant modified vaccinia virus Ankara–simian immunodeficiency virus gag pol elicits cytotoxic T lymphocytes in rhesus monkeys detected by a major histocompatibility complex class I/peptide tetramer

PubMed Central

Seth, Aruna; Ourmanov, Ilnour; Kuroda, Marcelo J.; Schmitz, Jörn E.; Carroll, Miles W.; Wyatt, Linda S.; Moss, Bernard; Forman, Meryl A.; Hirsch, Vanessa M.; Letvin, Norman L.

1998-01-01

The utility of modified vaccinia virus Ankara (MVA) as a vector for eliciting AIDS virus-specific cytotoxic T lymphocytes (CTL) was explored in the simian immunodeficiency virus (SIV)/rhesus monkey model. After two intramuscular immunizations with recombinant MVA-SIVSM gag pol, the monkeys developed a Gag epitope-specific CTL response readily detected in peripheral blood lymphocytes by using a functional killing assay. Moreover, those immunizations also elicited a population of CD8+ T lymphocytes in the peripheral blood that bound a specific major histocompatibility complex class I/peptide tetramer. These Gag epitope-specific CD8+ T lymphocytes also were demonstrated by using both functional and tetramer-binding assays in lymph nodes of the immunized monkeys. These observations suggest that MVA may prove a useful vector for an HIV-1 vaccine. They also suggest that tetramer staining may be a useful technology for monitoring CTL generation in vaccine trials in nonhuman primates and in humans. PMID:9707609

Protective effects of a Modified Vaccinia Ankara-based vaccine candidate against Crimean-Congo Haemorrhagic Fever virus require both cellular and humoral responses.

PubMed

Dowall, Stuart D; Graham, Victoria A; Rayner, Emma; Hunter, Laura; Watson, Robert; Taylor, Irene; Rule, Antony; Carroll, Miles W; Hewson, Roger

2016-01-01

Crimean-Congo Haemorrhagic Fever (CCHF) is a severe tick-borne disease, endemic in many countries in Africa, the Middle East, Eastern Europe and Asia. There is no approved vaccine currently available against CCHF. The most promising candidate, which has previously been shown to confer protection in the small animal model, is a modified Vaccinia Ankara virus vector expressing the CCHF viral glycoprotein (MVA-GP). It has been shown that MVA-GP induces both humoral and cellular immunogenicity. In the present study, sera and T-lymphocytes were passively and adoptively transferred into recipient mice prior to challenge with CCHF virus. Results demonstrated that mediators from both arms of the immune system were required to demonstrate protective effects against lethal challenge.

Disruption of Microtubules Post-Virus Entry Enhances Adeno-Associated Virus Vector Transduction

PubMed Central

Xiao, Ping-Jie; Mitchell, Angela M.; Huang, Lu; Li, Chengwen; Samulski, R. Jude

2016-01-01

Perinuclear retention of viral particles is a poorly understood phenomenon observed during many virus infections. In this study, we investigated whether perinuclear accumulation acts as a barrier to limit recombinant adeno-associated virus (rAAV) transduction. After nocodazole treatment to disrupt microtubules at microtubule-organization center (MT-MTOC) after virus entry, we observed higher rAAV transduction. To elucidate the role of MT-MTOC in rAAV infection and study its underlying mechanisms, we demonstrated that rAAV's perinuclear localization was retained by MT-MTOC with fluorescent analysis, and enhanced rAAV transduction from MT-MTOC disruption was dependent on the rAAV capsid's nuclear import signals. Interestingly, after knocking down RhoA or inhibiting its downstream effectors (ROCK and Actin), MT-MTOC disruption failed to increase rAAV transduction or nuclear entry. These data suggest that enhancement of rAAV transduction is the result of increased trafficking to the nucleus via the RhoA-ROCK-Actin pathway. Ten-fold higher rAAV transduction was also observed by disrupting MT-MTOC in brain, liver, and tumor in vivo. In summary, this study indicates that virus perinuclear accumulation at MT-MTOC is a barrier-limiting parameter for effective rAAV transduction and defines a novel defense mechanism by which host cells restrain viral invasion. PMID:26942476

Vaccination with Combination DNA and Virus-Like Particles Enhances Humoral and Cellular Immune Responses upon Boost with Recombinant Modified Vaccinia Virus Ankara Expressing Human Immunodeficiency Virus Envelope Proteins.

PubMed

Gangadhara, Sailaja; Kwon, Young-Man; Jeeva, Subbiah; Quan, Fu-Shi; Wang, Baozhong; Moss, Bernard; Compans, Richard W; Amara, Rama Rao; Jabbar, M Abdul; Kang, Sang-Moo

2017-12-19

Heterologous prime boost with DNA and recombinant modified vaccinia virus Ankara (rMVA) vaccines is considered as a promising vaccination approach against human immunodeficiency virus (HIV-1). To further enhance the efficacy of DNA-rMVA vaccination, we investigated humoral and cellular immune responses in mice after three sequential immunizations with DNA, a combination of DNA and virus-like particles (VLP), and rMVA expressing HIV-1 89.6 gp120 envelope proteins (Env). DNA prime and boost with a combination of VLP and DNA vaccines followed by an rMVA boost induced over a 100-fold increase in Env-specific IgG antibody titers compared to three sequential immunizations with DNA and rMVA. Cellular immune responses were induced by VLP-DNA and rMVA vaccinations at high levels in CD8 T cells, CD4 T cells, and peripheral blood mononuclear cells secreting interferon (IFN)-γ, and spleen cells producing interleukin (IL)-2, 4, 5 cytokines. This study suggests that a DNA and VLP combination vaccine with MVA is a promising strategy in enhancing the efficacy of DNA-rMVA vaccination against HIV-1.

Immune and histopathological responses in animals vaccinated with recombinant vaccinia viruses that express individual genes of human respiratory syncytial virus.

PubMed

Stott, E J; Taylor, G; Ball, L A; Anderson, K; Young, K K; King, A M; Wertz, G W

1987-12-01

Previous reports have established that vaccinia virus (VV) recombinants expressing G, F, or N protein of respiratory syncytial (RS) virus protect small animals against intranasal challenge with live RS virus. This work demonstrates that a variety of parameters affect the protection induced by recombinant viruses. The route of vaccination, the subtype of challenge virus, and the species used influenced the antibody titers and extent of protection. During these studies, observations were also made on the subclass of antibody generated, and pulmonary histopathological changes induced by challenge after vaccination were noted. The effect of route of inoculation on host response was examined by vaccinating mice intranasally, intraperitoneally, or by scarification with a recombinant VV expressing the RS virus G glycoprotein. Intranasal vaccination induced 25-fold-higher titers of antibody to RS virus in the lung than the intraperitoneal route did, but both routes resulted in complete suppression of virus replication after intranasal challenge 21 days after vaccination. Scarification was a less effective method of vaccination. The antibody induced by recombinant VV in mice was mostly immunoglobulin G2a (IgG2a) with some IgG2b. No antibody to RS virus was detected in the IgA, IgM, IgG1, or IgG3 subclass irrespective of the vaccination route. The G and F glycoproteins were shown to elicit similar subclasses of antibody. However, animals vaccinated with the G and F vectors differed strikingly in their response to challenge by heterologous virus. Mice or cotton rats vaccinated with recombinant VV carrying the G gene of RS virus were protected against challenge only with homologous subtype A virus. Vaccination with a recombinant VV expressing the F glycoprotein induced protection against both homologous and heterologous subtype B virus challenge. The protection induced in mice was greater than that detected in cotton rats, indicating that the host may also affect immunity

Distinct Gene Expression Profiles in Peripheral Blood Mononuclear Cells from Patients Infected with Vaccinia Virus, Yellow Fever 17D Virus, or Upper Respiratory Infections Running Title: PBMC Expression Response to Viral Agents

PubMed Central

Scherer, Christina A.; Magness, Charles L.; Steiger, Kathryn V.; Poitinger, Nicholas D.; Caputo, Christine M.; Miner, Douglas G.; Winokur, Patricia L.; Klinzman, Donna; McKee, Janice; Pilar, Christine; Ward, Patricia A.; Gillham, Martha H.; Haulman, N. Jean; Stapleton, Jack T.; Iadonato, Shawn P.

2007-01-01

Gene expression in human peripheral blood mononuclear cells was systematically evaluated following smallpox and yellow fever vaccination, and naturally occurring upper respiratory infection (URI). All three infections were characterized by the induction of many interferon stimulated genes, as well as enhanced expression of genes involved in proteolysis and antigen presentation. Vaccinia infection was also characterized by a distinct expression signature composed of up-regulation of monocyte response genes, with repression of genes expressed by B and T-cells. In contrast, the yellow fever host response was characterized by a suppression of ribosomal and translation factors, distinguishing this infection from vaccinia and URI. No significant URI-specific signature was observed, perhaps reflecting greater heterogeneity in the study population and etiological agents. Taken together, these data suggest that specific host gene expression signatures may be identified that distinguish one or a small number of virus agents. PMID:17651872

The ubiquitin-proteasome system is essential for the productive entry of Japanese encephalitis virus.

PubMed

Wang, Shaobo; Liu, Haibin; Zu, Xiangyang; Liu, Yang; Chen, Liman; Zhu, Xueqin; Zhang, Leike; Zhou, Zheng; Xiao, Gengfu; Wang, Wei

2016-11-01

The host-virus interaction during the cellular entry of Japanese encephalitis virus (JEV) is poorly characterized. The ubiquitin-proteasome system (UPS), the major intracellular proteolytic pathway, mediates diverse cellular processes, including endocytosis and signal transduction, which may be involved in the entry of virus. Here, we showed that the proteasome inhibitors, MG132 and lactacystin, impaired the productive entry of JEV by effectively interfering with viral intracellular trafficking at the stage between crossing cell membrane and the initial translation of the viral genome after uncoating. Using confocal microscopy, it was demonstrated that a proportion of the internalized virions were misdirected to lysosomes following treatment with MG132, resulting in non-productive entry. In addition, using specific siRNAs targeting ubiquitin, we verified that protein ubiquitination was involved in the entry of JEV. Overall, our study demonstrated the UPS is essential for the productive entry of JEV and might represent a potential antiviral target for JEV infection. Copyright © 2016 Elsevier Inc. All rights reserved.

Receptors and routes of dengue virus entry into the host cells.

PubMed

Cruz-Oliveira, Christine; Freire, João Miguel; Conceição, Thaís M; Higa, Luiza M; Castanho, Miguel A R B; Da Poian, Andrea T

2015-03-01

Dengue is the most prevalent arthropod-borne viral disease, caused by dengue virus, a member of the Flaviviridae family. Its worldwide incidence is now a major health problem, with 2.5 billion people living in risk areas. In this review, we integrate the structural rearrangements of each viral protein and their functions in all the steps of virus entry into the host cells. We describe in detail the putative receptors and attachment factors in mammalian and mosquito cells, and the recognition of viral immunocomplexes via Fcγ receptor in immune cells. We also discuss that virus internalization might occur through distinct entry pathways, including clathrin-mediated or non-classical clathrin-independent endocytosis, depending on the host cell and virus serotype or strain. The implications of viral maturation in virus entry are also explored. Finally, we discuss the mechanisms of viral genome access to the cytoplasm. This includes the role of low pH-induced conformational changes in the envelope protein that mediate membrane fusion, and original insights raised by our recent work that supports the hypothesis that capsid protein would also be an active player in this process, acting on viral genome translocation into the cytoplasm. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Role of phosphatidylserine receptors in enveloped virus infection.

PubMed

Morizono, Kouki; Chen, Irvin S Y

2014-04-01

. We were the first to report that a bifunctional serum protein, Gas6, bridges envelope phosphatidylserine to a cell surface receptor, Axl. Recent studies demonstrated that many envelope viruses, including vaccinia, dengue, West Nile, and Ebola viruses, utilize Axl/Gas6 to facilitate their entry, suggesting that the phosphatidylserine-mediated viral entry mechanism can be shared by various enveloped viruses. In addition to Axl/Gas6, various molecules are known to recognize phosphatidylserine; however, the effects of these molecules on virus binding and entry have not been comprehensively evaluated and compared. In this study, we examined most human phosphatidylserine-recognizing molecules for their abilities to facilitate viral infection. The results provide insights into the role(s) of envelope phosphatidylserine in viral infection, which can be applicable to the development of novel antiviral reagents that block phosphatidylserine-mediated viral entry.

Analysis of the entry mechanism of Crimean-Congo hemorrhagic fever virus, using a vesicular stomatitis virus pseudotyping system.

PubMed

Suda, Yuto; Fukushi, Shuetsu; Tani, Hideki; Murakami, Shin; Saijo, Masayuki; Horimoto, Taisuke; Shimojima, Masayuki

2016-06-01

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease causing severe hemorrhagic symptoms with a nearly 30 % case-fatality rate in humans. The experimental use of CCHF virus (CCHFV), which causes CCHF, requires high-biosafety-level (BSL) containment. In contrast, pseudotyping of various viral glycoproteins (GPs) onto vesicular stomatitis virus (VSV) can be used in facilities with lower BSL containment, and this has facilitated studies on the viral entry mechanism and the measurement of neutralizing activity, especially for highly pathogenic viruses. In the present study, we generated high titers of pseudotyped VSV bearing the CCHFV envelope GP and analyzed the mechanisms involved in CCHFV infection. A partial deletion of the CCHFV GP cytoplasmic domain increased the titer of the pseudotyped VSV, the entry mechanism of which was dependent on the CCHFV envelope GP. Using the pseudotype virus, DC-SIGN (a calcium-dependent [C-type] lectin cell-surface molecule) was revealed to enhance viral infection and act as an entry factor for CCHFV.

The V domain of dog PVRL4 (nectin-4) mediates canine distemper virus entry and virus cell-to-cell spread

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delpeut, Sebastien; Noyce, Ryan S.; IWK Health Centre, Canadian Center for Vaccinology, Goldbloom Pavilion, Halifax, Nova Scotia, Canada B3H 1X5

The entry of canine distemper virus (CDV) is a multistep process that involves the attachment of CDV hemagglutinin (H) to its cellular receptor, followed by fusion between virus and cell membranes. Our laboratory recently identified PVRL4 (nectin-4) to be the epithelial receptor for measles and canine distemper viruses. In this study, we demonstrate that the V domain of PVRL4 is critical for CDV entry and virus cell-to-cell spread. Furthermore, four key amino acid residues within the V domain of dog PVRL4 and two within the CDV hemagglutinin were shown to be essential for receptor-mediated virus entry. - Highlights: • PVRL4more » (nectin-4) is the epithelial cell receptor for measles and canine distemper viruses. • V domain of PVRL4 is critical for CDV entry, cell-to-cell spread, and syncytia formation. • Chimeric PVRL1 backbone substituted with the V domain of PVRL4 can function as a receptor. • Amino acids (F132/P133/A134/G135) within the V domain are essential for PVRL4 receptor activity. • Amino acids (P493/Y539) within CDV H protein are essential for PVRL4 receptor interaction.« less

Myristoylation increases the CD8+T-cell response to a GFP prototype antigen delivered by modified vaccinia virus Ankara.

PubMed

Marr, Lisa; Lülf, Anna-Theresa; Freudenstein, Astrid; Sutter, Gerd; Volz, Asisa

2016-04-01

Activation of CD8(+)T-cells is an essential part of immune responses elicited by recombinant modified vaccinia virus Ankara (MVA). Strategies to enhance T-cell responses to antigens may be particularly necessary for broadly protective immunization against influenza A virus infections or for candidate vaccines targeting chronic infections and cancer. Here, we tested recombinant MVAs that targeted a model antigen, GFP, to different localizations in infected cells. In vitro characterization demonstrated that GFP accumulated in the nucleus (MVA-nls-GFP), associated with cellular membranes (MVA-myr-GFP) or was equally distributed throughout the cell (MVA-GFP). On vaccination, we found significantly higher levels of GFP-specific CD8(+)T-cells in MVA-myr-GFP-vaccinated BALB/c mice than in those immunized with MVA-GFP or MVA-nls-GFP. Thus, myristoyl modification may be a useful strategy to enhance CD8(+)T-cell responses to MVA-delivered target antigens.

Entry Pathways of Herpes Simplex Virus Type 1 into Human Keratinocytes Are Dynamin- and Cholesterol-Dependent

PubMed Central

Hsu, Mei-Ju; Rixon, Frazer J.; Knebel-Mörsdorf, Dagmar

2011-01-01

Herpes simplex virus type 1 (HSV-1) can enter cells via endocytic pathways or direct fusion at the plasma membrane depending on the cell line and receptor(s). Most studies into virus entry have used cultured fibroblasts but since keratinocytes represent the primary entry site for HSV-1 infection in its human host, we initiated studies to characterize the entry pathway of HSV-1 into human keratinocytes. Electron microscopy studies visualized free capsids in the cytoplasm and enveloped virus particles in vesicles suggesting viral uptake both by direct fusion at the plasma membrane and by endocytic vesicles. The ratio of the two entry modes differed in primary human keratinocytes and in the keratinocyte cell line HaCaT. Inhibitor studies further support a role for endocytosis during HSV-1 entry. Infection was inhibited by the cholesterol-sequestering drug methyl-β-cyclodextrin, which demonstrates the requirement for host cholesterol during virus entry. Since the dynamin-specific inhibitor dynasore and overexpression of a dominant-negative dynamin mutant blocked infection, we conclude that the entry pathways into keratinocytes are dynamin-mediated. Electron microscopy studies confirmed that virus uptake is completely blocked when the GTPase activity of dynamin is inhibited. Ex vivo infection of murine epidermis that was treated with dynasore further supports the essential role of dynamin during entry into the epithelium. Thus, we conclude that HSV-1 can enter human keratinocytes by alternative entry pathways that require dynamin and host cholesterol. PMID:22022400

Mechanism of Cell Entry and Transformation by Enzootic Nasal Tumor Virus

PubMed Central

Dirks, Clarissa; Duh, Fuh-Mei; Rai, Sharath K.; Lerman, Michael I.; Miller, A. Dusty

2002-01-01

Enzootic nasal tumor virus (ENTV) induces nasal epithelial cancer in infected sheep, but it is a simple retrovirus lacking a known oncogene. ENTV is closely related to jaagsiekte sheep retrovirus (JSRV), which also causes cancer in sheep but in the epithelial cells of the lower airways and alveoli. Here we show that as with JSRV, the envelope (Env) protein of ENTV can transform cultured cells and thus is likely to be responsible for oncogenesis in animals. In addition, the ENTV Env protein mediates virus entry using the same receptor as does JSRV Env, the candidate tumor suppressor Hyal2. However, ENTV Env mediates entry into cells from a more restricted range of species than does JSRV, and based on this finding we have identified amino acid regions in the Env proteins that are important for virus entry. Also, because ENTV does not efficiently use human Hyal2 as a receptor, we cloned the ovine Hyal2 cDNA and show that the encoded protein functions as an efficient receptor for both ENTV and JSRV. In summary, although ENTV and JSRV use the same cell surface receptor for cell entry and apparently transform cells by the same mechanism, they induce cancer in different tissues of infected sheep, indicating that oncogenesis is regulated at some other level. The transcriptional regulatory elements in these viruses are quite different, indicating that tissue-specific oncogenesis is likely regulated at the level of viral gene expression. PMID:11836391

[Safety and efficacy of an antirabies vaccine consisting of recombinant vaccinia-rabies virus administered orally to the fox, dog and cat].

PubMed

Blancou, J; Artois, M; Brochier, B; Thomas, I; Pastoret, P P; Desmettre, P; Languet, B; Kiény, M P

1989-01-01

One of the most promising ways to control rabies in wildlife seems to be the distribution of bait containing an anti-rabies vaccine. So far, the most widely used vaccines were modified live viruses (SAD strain or derivatives). Nevertheless, these strains retain some pathogenicity for non-target species. A novel vaccine was proposed consisting of genetically modified vaccinia virus (strain Copenhagen, thermosensitive ts 26) expressing the foreign glycoprotein G for the rabies virus (strain ERA). Different doses of this recombinant virus were administered orally to 59 foxes (Vulpes vulpes) and their antibodies were titrated before challenge. Foxes (8/8) resisted 1 month after vaccination with 10(7) plaque forming units (PFU), or 4/4 after 18 months. Seroconversion among dogs was 4/4 after vaccination with 10(9,6) PFU and 4/4 among cats after vaccination with 10(8) PFU. These dogs (4/4) and cats (3/4) resisted the challenge 2-3 months after vaccination. This vaccine thus appears to be potent and safe in these species. Its properties are discussed.

Protective effects of a Modified Vaccinia Ankara-based vaccine candidate against Crimean-Congo Haemorrhagic Fever virus require both cellular and humoral responses

PubMed Central

Dowall, Stuart D.; Graham, Victoria A.; Rayner, Emma; Hunter, Laura; Watson, Robert; Taylor, Irene; Rule, Antony; Carroll, Miles W.; Hewson, Roger

2016-01-01

Crimean-Congo Haemorrhagic Fever (CCHF) is a severe tick-borne disease, endemic in many countries in Africa, the Middle East, Eastern Europe and Asia. There is no approved vaccine currently available against CCHF. The most promising candidate, which has previously been shown to confer protection in the small animal model, is a modified Vaccinia Ankara virus vector expressing the CCHF viral glycoprotein (MVA-GP). It has been shown that MVA-GP induces both humoral and cellular immunogenicity. In the present study, sera and T-lymphocytes were passively and adoptively transferred into recipient mice prior to challenge with CCHF virus. Results demonstrated that mediators from both arms of the immune system were required to demonstrate protective effects against lethal challenge. PMID:27272940

Characterization of Bunyamwera virus S RNA that is transcribed and replicated by the L protein expressed from recombinant vaccinia virus.

PubMed

Jin, H; Elliott, R M

1993-03-01

Analysis of the 5' termini of Bunyamwera virus S segment mRNAs by cloning and sequence analysis revealed the presence of nonviral, heterogeneous sequences 12 to 17 bases long. This is similar to reports for other members of the family Bunyaviridae and is taken to indicate that mRNA transcription is primed by a "cap-snatching" mechanism. The 3' end of the Bunyamwera virus S mRNA was mapped, by using an RNase protection assay, to 100 to 110 nucleotides upstream of the 3' end of the template. Previously we reported expression of the Bunyamwera virus L (polymerase) protein by recombinant vaccinia virus and demonstrated that the recombinant L protein was functional in terms of RNA synthesis activity in a nucleocapsid transfection assay (H. Jin and R. M. Elliott, J. Virol. 65: 4182-4189, 1991). In the present study we further analyze the RNAs made by using this system and show that positive-sense RNAs contain 5' nonviral sequences. Hence the initiation of mRNA transcription by the recombinant L protein resembles that seen during authentic bunyavirus infection and suggests that the L protein has the endonuclease activity which generates the primers. Some of these positive-sense transcripts terminated at the mRNA termination site, but the majority read through to the end of the template. No primer sequences were found at the 5' terminal of negative-sense RNAs. The recombinant L protein was able to replicate negative-sense RNA supplied by transfected virion-derived nucleocapsids, and both positive- and negative-sense RNAs were synthesized. These results indicate that the recombinant L protein has both transcriptase and replicase activities.

Characterization of Bunyamwera virus S RNA that is transcribed and replicated by the L protein expressed from recombinant vaccinia virus.

PubMed Central

Jin, H; Elliott, R M

1993-01-01

Analysis of the 5' termini of Bunyamwera virus S segment mRNAs by cloning and sequence analysis revealed the presence of nonviral, heterogeneous sequences 12 to 17 bases long. This is similar to reports for other members of the family Bunyaviridae and is taken to indicate that mRNA transcription is primed by a "cap-snatching" mechanism. The 3' end of the Bunyamwera virus S mRNA was mapped, by using an RNase protection assay, to 100 to 110 nucleotides upstream of the 3' end of the template. Previously we reported expression of the Bunyamwera virus L (polymerase) protein by recombinant vaccinia virus and demonstrated that the recombinant L protein was functional in terms of RNA synthesis activity in a nucleocapsid transfection assay (H. Jin and R. M. Elliott, J. Virol. 65: 4182-4189, 1991). In the present study we further analyze the RNAs made by using this system and show that positive-sense RNAs contain 5' nonviral sequences. Hence the initiation of mRNA transcription by the recombinant L protein resembles that seen during authentic bunyavirus infection and suggests that the L protein has the endonuclease activity which generates the primers. Some of these positive-sense transcripts terminated at the mRNA termination site, but the majority read through to the end of the template. No primer sequences were found at the 5' terminal of negative-sense RNAs. The recombinant L protein was able to replicate negative-sense RNA supplied by transfected virion-derived nucleocapsids, and both positive- and negative-sense RNAs were synthesized. These results indicate that the recombinant L protein has both transcriptase and replicase activities. Images PMID:8437222

Single-Particle Tracking of Human Immunodeficiency Virus Type 1 Productive Entry into Human Primary Macrophages.

PubMed

Li, Qin; Li, Wei; Yin, Wen; Guo, Jia; Zhang, Zhi-Ping; Zeng, Dejun; Zhang, Xiaowei; Wu, Yuntao; Zhang, Xian-En; Cui, Zongqiang

2017-04-25

Macrophages are one of the major targets of human immunodeficiency virus (HIV-1), but the viral entry pathway remains poorly understood in these cells. Noninvasive virus labeling and single-virus tracking are effective tools for studying virus entry. Here, we constructed a quantum dot (QD)-encapsulated infectious HIV-1 particle to track viral entry at a single-particle level in live human primary macrophages. QDs were encapsulated in HIV-1 virions by incorporating viral accessory protein Vpr-conjugated QDs during virus assembly. With the HIV-1 particles encapsulating QDs, we monitored the early phase of viral infection in real time and observed that, during infection, HIV-1 was endocytosed in a clathrin-mediated manner; the particles were translocated into Rab5A-positive endosomes, and the core was released into the cytoplasm by viral envelope-mediated endosomal fusion. Drug inhibition assays verified that endosome fusion contributes to HIV-1 productive infection in primary macrophages. Additionally, we observed that a dynamic actin cytoskeleton is critical for HIV-1 entry and intracellular migration in primary macrophages. HIV-1 dynamics and infection could be blocked by multiple different actin inhibitors. Our study revealed a productive entry pathway in macrophages that requires both endosomal function and actin dynamics, which may assist in the development of inhibitors to block the HIV entry in macrophages.

Combined prime-boost vaccination against tick-borne encephalitis (TBE) using a recombinant vaccinia virus and a bacterial plasmid both expressing TBE virus non-structural NS1 protein

PubMed Central

Aleshin, SE; Timofeev, AV; Khoretonenko, MV; Zakharova, LG; Pashvykina, GV; Stephenson, JR; Shneider, AM; Altstein, AD

2005-01-01

Background Heterologous prime-boost immunization protocols using different gene expression systems have proven to be successful tools in protecting against various diseases in experimental animal models. The main reason for using this approach is to exploit the ability of expression cassettes to prime or boost the immune system in different ways during vaccination procedures. The purpose of the project was to study the ability of recombinant vaccinia virus (VV) and bacterial plasmid, both carrying the NS1 gene from tick-borne encephalitis (TBE) virus under the control of different promoters, to protect mice against lethal challenge using a heterologous prime-boost vaccination protocol. Results The heterologous prime-boost vaccination protocol, using a VV recombinant and bacterial plasmid, both containing the NS1 TBE virus protein gene under the control of different promoters, achieved a high level of protection in mice against lethal challenge with a highly pathogenic TBE virus strain. No signs of pronounced TBE infection were detected in the surviving animals. Conclusion Heterologous prime-boost vaccination protocols using recombinant VV and bacterial plasmids could be used for the development of flavivirus vaccines. PMID:16076390

A single immunization with modified vaccinia virus Ankara-based influenza virus H7 vaccine affords protection in the influenza A(H7N9) pneumonia ferret model.

PubMed

Kreijtz, Joost H C M; Wiersma, Lidewij C M; De Gruyter, Heidi L M; Vogelzang-van Trierum, Stella E; van Amerongen, Geert; Stittelaar, Koert J; Fouchier, Ron A M; Osterhaus, Albert D M E; Sutter, Gerd; Rimmelzwaan, Guus F

2015-03-01

Since the first reports in early 2013, >440 human cases of infection with avian influenza A(H7N9) have been reported including 122 fatalities. After the isolation of the first A(H7N9) viruses, the nucleotide sequences became publically available. Based on the coding sequence of the influenza virus A/Shanghai/2/2013 hemagglutinin gene, a codon-optimized gene was synthesized and cloned into a recombinant modified vaccinia virus Ankara (MVA). This MVA-H7-Sh2 viral vector was used to immunize ferrets and proved to be immunogenic, even after a single immunization. Subsequently, ferrets were challenged with influenza virus A/Anhui/1/2013 via the intratracheal route. Unprotected animals that were mock vaccinated or received empty vector developed interstitial pneumonia characterized by a marked alveolitis, accompanied by loss of appetite, weight loss, and heavy breathing. In contrast, animals vaccinated with MVA-H7-Sh2 were protected from severe disease. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Hepatitis C virus utilizes VLDLR as a novel entry pathway.

PubMed

Ujino, Saneyuki; Nishitsuji, Hironori; Hishiki, Takayuki; Sugiyama, Kazuo; Takaku, Hiroshi; Shimotohno, Kunitada

2016-01-05

Various host factors are involved in the cellular entry of hepatitis C virus (HCV). In addition to the factors previously reported, we discovered that the very-low-density lipoprotein receptor (VLDLR) mediates HCV entry independent of CD81. Culturing Huh7.5 cells under hypoxic conditions significantly increased HCV entry as a result of the expression of VLDLR, which was not expressed under normoxic conditions in this cell line. Ectopic VLDLR expression conferred susceptibility to HCV entry of CD81-deficient Huh7.5 cells. Additionally, VLDLR-mediated HCV entry was not affected by the knockdown of cellular factors known to act as HCV receptors or HCV entry factors. Because VLDLR is expressed in primary human hepatocytes, our results suggest that VLDLR functions in vivo as an HCV receptor independent of canonical CD81-mediated HCV entry.

Efficacy and safety of a modified vaccinia Ankara (MVA) vectored plague vaccine in mice

PubMed Central

Brewoo, Joseph N.; Powell, Tim D.; Stinchcomb, Dan T.; Osorio, Jorge E.

2010-01-01

The efficacy and safety of plague vaccines based on the modified vaccinia Ankara (MVA) viral vector was evaluated. MVA recombinants were constructed expressing Yersinia pestis antigens under the translational control of the encephalomyocarditis virus (EMCV) internal ribosomal entry site (IRES) and/or fused to the tissue plasminogen activator (tPA) secretory signal. A MVA/Y. pestis recombinant that expressed a truncated version of the low-calcium response V antigen (MVA/IRES/tPA/V307), conferred significant protection (87.5%–100%) against intranasal or intraperitoneal challenge with CO92 (encapsulated) or Java 9 (non-encapsulated) strains of Y pestis, respectively. In contrast, a MVA/Y. pestis recombinant that expressed the full-length V antigen provided only 37.5% protection against challenge with CO92 or Java 9 strains, respectively. Interestingly, a MVA/Y. pestis recombinant that expressed the capsular protein (F1) did not elicit significant antibody titers but still conferred 50% and 25% protection against CO92 or Java 9 challenge, respectively. The MVA/Y. pestis recombinant viruses did not demonstrate any mortality or morbidity in SCID mice. Based on their safety and efficacy in mice, these MVA/Y. pestis recombinants are candidates for further development as biodefense and public health vaccines. PMID:20638759

The Polyomaviridae: Contributions of virus structure to our understanding of virus receptors and infectious entry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neu, Ursula; Stehle, Thilo; Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232

This review summarizes the field's major findings related to the characterization of polyomavirus structures and to the characterization of virus receptors and mechanisms of host cell invasion. The four members of the family that have received the most attention in this regard are the mouse polyomavirus (mPyV), the monkey polyomavirus SV40, and the two human polyomaviruses, JCV and BKV. The structures of both the mPyV and SV40 alone and in complex with receptor fragments have been solved to high resolution. The majority of polyomaviruses recognize terminal sialic acid in either an {alpha}2,3 linkage or an {alpha}2,6 linkage to the underlyingmore » galactose. Studies on virus structure, receptor utilization and mechanisms of entry have led to new insights into how these viruses interact in an active way with cells to ensure the nuclear delivery and expression of their genomes. Critical work on virus entry has led to the discovery of a pH neutral endocytic compartment that accepts cargo from caveolae and to novel roles for endoplasmic reticulum (ER) associated factors in virus uncoating and penetration of ER membranes. This review will summarize the major findings and compare and contrast the mechanisms used by these viruses to infect cells.« less

Ectopic expression of vaccinia virus E3 and K3 cannot rescue ectromelia virus replication in rabbit RK13 cells.

PubMed

Hand, Erin S; Haller, Sherry L; Peng, Chen; Rothenburg, Stefan; Hersperger, Adam R

2015-01-01

As a group, poxviruses have been shown to infect a wide variety of animal species. However, there is individual variability in the range of species able to be productively infected. In this study, we observed that ectromelia virus (ECTV) does not replicate efficiently in cultured rabbit RK13 cells. Conversely, vaccinia virus (VACV) replicates well in these cells. Upon infection of RK13 cells, the replication cycle of ECTV is abortive in nature, resulting in a greatly reduced ability to spread among cells in culture. We observed ample levels of early gene expression but reduced detection of virus factories and severely blunted production of enveloped virus at the cell surface. This work focused on two important host range genes, named E3L and K3L, in VACV. Both VACV and ECTV express a functional protein product from the E3L gene, but only VACV contains an intact K3L gene. To better understand the discrepancy in replication capacity of these viruses, we examined the ability of ECTV to replicate in wild-type RK13 cells compared to cells that constitutively express E3 and K3 from VACV. The role these proteins play in the ability of VACV to replicate in RK13 cells was also analyzed to determine their individual contribution to viral replication and PKR activation. Since E3L and K3L are two relevant host range genes, we hypothesized that expression of one or both of them may have a positive impact on the ability of ECTV to replicate in RK13 cells. Using various methods to assess virus growth, we did not detect any significant differences with respect to the replication of ECTV between wild-type RK13 compared to versions of this cell line that stably expressed VACV E3 alone or in combination with K3. Therefore, there remain unanswered questions related to the factors that limit the host range of ECTV.

Modified vaccinia virus Ankara expressing the hemagglutinin of pandemic (H1N1) 2009 virus induces cross-protective immunity against Eurasian 'avian-like' H1N1 swine viruses in mice.

PubMed

Castrucci, Maria R; Facchini, Marzia; Di Mario, Giuseppina; Garulli, Bruno; Sciaraffia, Ester; Meola, Monica; Fabiani, Concetta; De Marco, Maria A; Cordioli, Paolo; Siccardi, Antonio; Kawaoka, Yoshihiro; Donatelli, Isabella

2014-05-01

To examine cross-reactivity between hemagglutinin (HA) derived from A/California/7/09 (CA/09) virus and that derived from representative Eurasian "avian-like" (EA) H1N1 swine viruses isolated in Italy between 1999 and 2008 during virological surveillance in pigs. Modified vaccinia virus Ankara (MVA) expressing the HA gene of CA/09 virus (MVA-HA-CA/09) was used as a vaccine to investigate cross-protective immunity against H1N1 swine viruses in mice. Two classical swine H1N1 (CS) viruses and four representative EA-like H1N1 swine viruses previously isolated during outbreaks of respiratory disease in pigs on farms in Northern Italy were used in this study. Female C57BL/6 mice were vaccinated with MVA/HA/CA/09 and then challenged intranasally with H1N1 swine viruses. Cross-reactive antibody responses were determined by hemagglutination- inhibition (HI) and virus microneutralizing (MN) assays of sera from MVA-vaccinated mice. The extent of protective immunity against infection with H1N1 swine viruses was determined by measuring lung viral load on days 2 and 4 post-challenge. Systemic immunization of mice with CA/09-derived HA, vectored by MVA, elicited cross-protective immunity against recent EA-like swine viruses. This immune protection was related to the levels of cross-reactive HI antibodies in the sera of the immunized mice and was dependent on the similarity of the antigenic site Sa of H1 HAs. Our findings suggest that the herd immunity elicited in humans by the pandemic (H1N1) 2009 virus could limit the transmission of recent EA-like swine HA genes into the influenza A virus gene pool in humans. © 2013 The Authors Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Protective immunity against influenza in HLA-A2 transgenic mice by modified vaccinia virus Ankara vectored vaccines containing internal influenza proteins.

PubMed

Di Mario, Giuseppina; Sciaraffia, Ester; Facchini, Marzia; Gubinelli, Francesco; Soprana, Elisa; Panigada, Maddalena; Bernasconi, Valentina; Garulli, Bruno; Siccardi, Antonio; Donatelli, Isabella; Castrucci, Maria R

2017-03-01

The emergence of novel strains of influenza A viruses with hemagglutinins (HAs) that are antigenically distinct from those circulating in humans, and thus have pandemic potential, pose concerns and call for the development of more broadly protective influenza vaccines. In the present study, modified vaccinia virus Ankara (MVA) encoding internal influenza antigens were evaluated for their immunogenicity and ability to protect HLA-A2.1 transgenic (AAD) mice from infection with influenza viruses. MVAs expressing NP (MVA-NP), M1 (MVA-M1) or polymerase PB1 (MVA-PB1) of A/California/4/09 (CA/09) virus were generated and used to immunize AAD mice. Antibodies and CD8+T cell responses were assessed by ELISA and ELISPOT, respectively, and challenge experiments were performed by infecting vaccinated mice with CA/09 virus. CD8+T cells specific to immunodominant and subdominant epitopes on the internal influenza proteins were elicited by MVA-based vectors in AAD mice, whereas influenza-specific antibodies were detected only in MVA-NP-immunized mice. Both M1- and NP-based MVA vaccines, regardless of whether they were applied individually or in combination, conferred protection against lethal influenza virus challenge. Our data further emphasize the promising potential of MVA vector expressing internal antigens toward the development of a universal influenza vaccine.

Proteome analysis of vaccinia virus IHD-W-infected HEK 293 cells with 2-dimensional gel electrophoresis and MALDI-PSD-TOF MS of on solid phase support N-terminally sulfonated peptides

PubMed Central

2011-01-01

Background Despite the successful eradication of smallpox by the WHO-led vaccination programme, pox virus infections remain a considerable health threat. The possible use of smallpox as a bioterrorism agent as well as the continuous occurrence of zoonotic pox virus infections document the relevance to deepen the understanding for virus host interactions. Since the permissiveness of pox infections is independent of hosts surface receptors, but correlates with the ability of the virus to infiltrate the antiviral host response, it directly depends on the hosts proteome set. In this report the proteome of HEK293 cells infected with Vaccinia Virus strain IHD-W was analyzed by 2-dimensional gel electrophoresis and MALDI-PSD-TOF MS in a bottom-up approach. Results The cellular and viral proteomes of VACV IHD-W infected HEK293 cells, UV-inactivated VACV IHD-W-treated as well as non-infected cells were compared. Derivatization of peptides with 4-sulfophenyl isothiocyanate (SPITC) carried out on ZipTipμ-C18 columns enabled protein identification via the peptides' primary sequence, providing improved s/n ratios as well as signal intensities of the PSD spectra. The expression of more than 24 human proteins was modulated by the viral infection. Effects of UV-inactivated and infectious viruses on the hosts' proteome concerning energy metabolism and proteins associated with gene expression and protein-biosynthesis were quite similar. These effects might therefore be attributed to virus entry and virion proteins. However, the modulation of proteins involved in apoptosis was clearly correlated to infectious viruses. Conclusions The proteome analysis of infected cells provides insight into apoptosis modulation, regulation of cellular gene expression and the regulation of energy metabolism. The confidence of protein identifications was clearly improved by the peptides' derivatization with SPITC on a solid phase support. Some of the identified proteins have not been described in the

Development of novel entry inhibitors targeting emerging viruses

PubMed Central

Zhou, Yanchen; Simmons, Graham

2013-01-01

Emerging viral diseases pose a unique risk to public health, and thus there is a need to develop therapies. A current focus of funding agencies, and hence research, is the development of broad-spectrum antivirals, and in particular, those targeting common cellular pathways. The scope of this article is to review screening strategies and recent advances in this area, with a particular emphasis on antivirals targeting the step of viral entry for emerging lipid-enveloped viruses such as Ebola virus and SARS-coronavirus. PMID:23199399

Venezuelan equine encephalitis virus entry mechanism requires late endosome formation and resists cell membrane cholesterol depletion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kolokoltsov, Andrey A.; Fleming, Elisa H.; Davey, Robert A.

2006-04-10

Virus envelope proteins determine receptor utilization and host range. The choice of receptor not only permits specific targeting of cells that express it, but also directs the virus into specific endosomal trafficking pathways. Disrupting trafficking can result in loss of virus infectivity due to redirection of virions to non-productive pathways. Identification of the pathway or pathways used by a virus is, thus, important in understanding virus pathogenesis mechanisms and for developing new treatment strategies. Most of our understanding of alphavirus entry has focused on the Old World alphaviruses, such as Sindbis and Semliki Forest virus. In comparison, very little ismore » known about the entry route taken by more pathogenic New World alphaviruses. Here, we use a novel contents mixing assay to identify the cellular requirements for entry of a New World alphavirus, Venezuelan equine encephalitis virus (VEEV). Expression of dominant negative forms of key endosomal trafficking genes shows that VEEV must access clathrin-dependent endocytic vesicles for membrane fusion to occur. Unexpectedly, the exit point is different from Old World alphaviruses that leave from early endosomes. Instead, VEEV also requires functional late endosomes. Furthermore, unlike the Old World viruses, VEEV entry is insensitive to cholesterol sequestration from cell membranes and may reflect a need to access an endocytic compartment that lacks cholesterol. This indicates fundamental differences in the entry route taken by VEEV compared to Old World alphaviruses.« less

Vaccinia Virus-mediated Expression of Human Erythropoietin in Tumors Enhances Virotherapy and Alleviates Cancer-related Anemia in Mice

PubMed Central

Nguyen, Duong H; Chen, Nanhai G; Zhang, Qian; Le, Ha T; Aguilar, Richard J; Yu, Yong A; Cappello, Joseph; Szalay, Aladar A

2013-01-01

Recombinant human erythropoietin (rhEPO), a glycoprotein hormone regulating red blood cell (RBC) formation, is used for the treatment of cancer-related anemia. The effect of rhEPO on tumor growth, however, remains controversial. Here, we report the construction and characterization of the recombinant vaccinia virus (VACV) GLV-1h210, expressing hEPO. GLV-1h210 was shown to replicate in and kill A549 lung cancer cells in culture efficiently. In mice bearing A549 lung cancer xenografts, treatment with a single intravenous dose of GLV-1h210 resulted in tumor-specific production and secretion of functional hEPO, which exerted an effect on RBC progenitors and precursors in the mouse bone marrow, leading to a significant increase in the number of RBCs and in the level of hemoglobin. Furthermore, virally expressed hEPO, but not exogenously added rhEPO, enhanced virus-mediated green fluorescent protein (GFP) expression in tumors and subsequently accelerated tumor regression when compared with the treatment with the parental virus GLV-1h68 or GLV-1h209 that expressed a nonfunctional hEPO protein. Moreover, intratumorally expressed hEPO caused enlarged tumoral microvessels, likely facilitating virus spreading. Taken together, VACV-mediated intratumorally expressed hEPO not only enhanced oncolytic virotherapy but also simultaneously alleviated cancer-related anemia. PMID:23765443

Weak vaccinia virus-induced NK cell regulation of CD4 T cells is associated with reduced NK cell differentiation and cytolytic activity.

PubMed

Hatfield, Steven D; Daniels, Keith A; O'Donnell, Carey L; Waggoner, Stephen N; Welsh, Raymond M

2018-06-01

Natural killer (NK) cells control antiviral adaptive immune responses in mice during some virus infections, but the universality of this phenomenon remains unknown. Lymphocytic choriomeningitis virus (LCMV) infection of mice triggered potent cytotoxic activity of NK cells (NK LCMV ) against activated CD4 T cells, tumor cells, and allogeneic lymphocytes. In contrast, NK cells activated by vaccinia virus (VACV) infection (NK VACV ) exhibited weaker cytolytic activity against each of these target cells. Relative to NK LCMV cells, NK VACV cells exhibited a more immature (CD11b - CD27 + ) phenotype, and lower expression levels of the activation marker CD69, cytotoxic effector molecules (perforin, granzyme B), and the transcription factor IRF4. NK VACV cells expressed higher levels of the inhibitory molecule NKG2A than NK LCMV cells. Consistent with this apparent lethargy, NK VACV cells only weakly constrained VACV-specific CD4 T-cell responses. This suggests that NK cell regulation of adaptive immunity, while universal, may be limited with viruses that poorly activate NK cells. Published by Elsevier Inc.

Broad-spectrum antiviral activity of chebulagic acid and punicalagin against viruses that use glycosaminoglycans for entry

PubMed Central

2013-01-01

Background We previously identified two hydrolyzable tannins, chebulagic acid (CHLA) and punicalagin (PUG) that blocked herpes simplex virus type 1 (HSV-1) entry and spread. These compounds inhibited viral glycoprotein interactions with cell surface glycosaminoglycans (GAGs). Based on this property, we evaluated their antiviral efficacy against several different viruses known to employ GAGs for host cell entry. Results Extensive analysis of the tannins’ mechanism of action was performed on a panel of viruses during the attachment and entry steps of infection. Virus-specific binding assays and the analysis of viral spread during treatment with these compounds were also conducted. CHLA and PUG were effective in abrogating infection by human cytomegalovirus (HCMV), hepatitis C virus (HCV), dengue virus (DENV), measles virus (MV), and respiratory syncytial virus (RSV), at μM concentrations and in dose-dependent manners without significant cytotoxicity. Moreover, the natural compounds inhibited viral attachment, penetration, and spread, to different degrees for each virus. Specifically, the tannins blocked all these steps of infection for HCMV, HCV, and MV, but had little effect on the post-fusion spread of DENV and RSV, which could suggest intriguing differences in the roles of GAG-interactions for these viruses. Conclusions CHLA and PUG may be of value as broad-spectrum antivirals for limiting emerging/recurring viruses known to engage host cell GAGs for entry. Further studies testing the efficacy of these tannins in vivo against certain viruses are justified. PMID:23924316

Pinpointing retrovirus entry sites in cells expressing alternatively spliced receptor isoforms by single virus imaging.

PubMed

Padilla-Parra, Sergi; Marin, Mariana; Kondo, Naoyuki; Melikyan, Gregory B

2014-06-16

The majority of viruses enter host cells via endocytosis. Current knowledge of viral entry pathways is largely based upon infectivity measurements following genetic and/or pharmacological interventions that disrupt vesicular trafficking and maturation. Imaging of single virus entry in living cells provides a powerful means to delineate viral trafficking pathways and entry sites under physiological conditions. Here, we visualized single avian retrovirus co-trafficking with markers for early (Rab5) and late (Rab7) endosomes, acidification of endosomal lumen and the resulting viral fusion measured by the viral content release into the cytoplasm. Virus-carrying vesicles either merged with the existing Rab5-positive early endosomes or slowly accumulated Rab5. The Rab5 recruitment to virus-carrying endosomes correlated with acidification of their lumen. Viral fusion occurred either in early (Rab5-positive) or intermediate (Rab5- and Rab7-positive) compartments. Interestingly, different isoforms of the cognate receptor directed virus entry from distinct endosomes. In cells expressing the transmembrane receptor, viruses preferentially entered and fused with slowly maturing early endosomes prior to accumulation of Rab7. By comparison, in cells expressing the GPI-anchored receptor, viruses entered both slowly and quickly maturing endosomes and fused with early (Rab5-positive) and intermediate (Rab5- and Rab7-positive) compartments. Since the rate of low pH-triggered fusion was independent of the receptor isoform, we concluded that the sites of virus entry are determined by the kinetic competition between endosome maturation and viral fusion. Our findings demonstrate the ability of this retrovirus to enter cells via alternative endocytic pathways and establish infection by releasing its content from distinct endosomal compartments.

Filopodia and Viruses: An Analysis of Membrane Processes in Entry Mechanisms

PubMed Central

Chang, Kenneth; Baginski, John; Hassan, Samer F.; Volin, Michael; Shukla, Deepak; Tiwari, Vaibhav

2016-01-01

Filopodia are thin, actin rich bundles protruding from cell plasma membranes, serving physiological purposes, such as probing the environment and facilitating cell-to-cell adhesion. Recent studies have highlighted that actively polymerized filopodial-protrusions are exploited during virus entry, trafficking, spread, and the development of clinical pathology of viral diseases. These observations have caused a surge in investigation of the key determinants of filopodial induction and their influence on cell topography including receptor expression for viral entry. It is now very clear that filopodia can provide unique opportunities for many viruses to invade host cells vertically during primary infection, or horizontally during virus spread from cell-to-cell. These emerging concepts can explain the unprecedented ability of viruses to invade both nearby and long-distant host cells, a feature that may directly contribute to viral tropism. In this review, we summarize the significance of filopodia in viral diseases and discuss future therapeutic possibilities to precisely target filopodial-flyovers to prevent or control infectious diseases. PMID:27014223

Ubiquitin in Influenza Virus Entry and Innate Immunity.

PubMed

Rudnicka, Alina; Yamauchi, Yohei

2016-10-24

Viruses are obligatory cellular parasites. Their mission is to enter a host cell, to transfer the viral genome, and to replicate progeny whilst diverting cellular immunity. The role of ubiquitin is to regulate fundamental cellular processes such as endocytosis, protein degradation, and immune signaling. Many viruses including influenza A virus (IAV) usurp ubiquitination and ubiquitin-like modifications to establish infection. In this focused review, we discuss how ubiquitin and unanchored ubiquitin regulate IAV host cell entry, and how histone deacetylase 6 (HDAC6), a cytoplasmic deacetylase with ubiquitin-binding activity, mediates IAV capsid uncoating. We also discuss the roles of ubiquitin in innate immunity and its implications in the IAV life cycle.

Ubiquitin in Influenza Virus Entry and Innate Immunity

PubMed Central

Rudnicka, Alina; Yamauchi, Yohei

2016-01-01

Viruses are obligatory cellular parasites. Their mission is to enter a host cell, to transfer the viral genome, and to replicate progeny whilst diverting cellular immunity. The role of ubiquitin is to regulate fundamental cellular processes such as endocytosis, protein degradation, and immune signaling. Many viruses including influenza A virus (IAV) usurp ubiquitination and ubiquitin-like modifications to establish infection. In this focused review, we discuss how ubiquitin and unanchored ubiquitin regulate IAV host cell entry, and how histone deacetylase 6 (HDAC6), a cytoplasmic deacetylase with ubiquitin-binding activity, mediates IAV capsid uncoating. We also discuss the roles of ubiquitin in innate immunity and its implications in the IAV life cycle. PMID:27783058

Vaccination of horses with a recombinant modified vaccinia Ankara virus (MVA) expressing African horse sickness (AHS) virus major capsid protein VP2 provides complete clinical protection against challenge.

PubMed

Alberca, Berta; Bachanek-Bankowska, Katarzyna; Cabana, Marta; Calvo-Pinilla, Eva; Viaplana, Elisenda; Frost, Lorraine; Gubbins, Simon; Urniza, Alicia; Mertens, Peter; Castillo-Olivares, Javier

2014-06-17

African horse sickness virus (AHSV) is an arthropod-borne pathogen that infects all species of equidae and causes high mortality in horses. Previously, a recombinant modified vaccinia Ankara (MVA) virus expressing the protein VP2 of AHSV serotype 4 was shown to induce virus neutralising antibodies in horses and protected interferon alpha receptor gene knock-out mice (IFNAR -/-) against virulent AHSV challenge. This study builds on the previous work, examining the protective efficacy of MVA-VP2 vaccination in the natural host of AHSV infection. A study group of 4 horses was vaccinated twice with a recombinant MVA virus expressing the major capsid protein (VP2) of AHSV serotype 9. Vaccinated animals and a control group of unvaccinated horses were then challenged with a virulent strain of AHSV-9. The vaccinated animals were completely protected against clinical disease and also against viraemia as measured by standard end-point dilution assays. In contrast, all control horses presented viraemia after challenge and succumbed to the infection. These results demonstrate the potential of recombinant MVA viruses expressing the outer capsid VP2 of AHSV as a protective vaccine against AHSV infection in the field. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Lassa virus entry requires a trigger-induced receptor switch

PubMed Central

Jae, Lucas T.; Raaben, Matthijs; Herbert, Andrew S.; Kuehne, Ana I.; Wirchnianski, Ariel S.; Soh, Timothy; Stubbs, Sarah H.; Janssen, Hans; Damme, Markus; Saftig, Paul; Whelan, Sean P.; Dye, John M.; Brummelkamp, Thijn R.

2014-01-01

Lassa virus spreads from rodents to humans and can lead to lethal hemorrhagic fever. Despite its broad tropism, chicken cells were reported to resist infection thirty years ago. We show that Lassa virus readily engaged its cell surface receptor α-dystroglycan in avian cells, but virus entry in susceptible species involved a pH-dependent switch to an intracellular receptor, the lysosome-resident protein LAMP1. Iterative haploid screens revealed that the sialyltransferase ST3GAL4 was required for the interaction of the virus glycoprotein with LAMP1. A single glycosylated residue in LAMP1, present in susceptible species but absent in birds, was essential for interaction with the Lassa virus envelope protein and subsequent infection. The resistance of Lamp1-deficient mice to Lassa virus highlights the relevance of this receptor switch in vivo. PMID:24970085

Virus and Host Mechanics Support Membrane Penetration and Cell Entry

PubMed Central

2016-01-01

Viruses are quasi-inert macromolecular assemblies. Their metastable conformation changes during entry into cells, when chemical and mechanical host cues expose viral membrane-interacting proteins. This leads to membrane rupture or fusion and genome uncoating. Importantly, virions tune their physical properties and enhance penetration and uncoating. For example, influenza virus softens at low pH to uncoat. The stiffness and pressure of adenovirus control uncoating and membrane penetration. Virus and host mechanics thus present new opportunities for antiviral therapy. PMID:26842477

Enhancement of CD8+ T-cell memory by removal of a vaccinia virus nuclear factor-κB inhibitor

PubMed Central

Ren, Hongwei; Ferguson, Brian J; de Motes, Carlos Maluquer; Sumner, Rebecca P; Harman, Laura E R; Smith, Geoffrey L

2015-01-01

Factors influencing T-cell responses are important for vaccine development but are incompletely understood. Here, vaccinia virus (VACV) protein N1 is shown to impair the development of both effector and memory CD8+ T cells and this correlates with its inhibition of nuclear factor-κB (NF-κB) activation. Infection with VACVs that either have the N1L gene deleted (vΔN1) or contain a I6E mutation (vN1.I6E) that abrogates its inhibition of NF-κB resulted in increased central and memory CD8+ T-cell populations, increased CD8+ T-cell cytotoxicity and lower virus titres after challenge. Furthermore, CD8+ memory T-cell function was increased following infection with vN1.I6E, with more interferon-γ production and greater protection against VACV infection following passive transfer to naive mice, compared with CD8+ T cells from mice infected with wild-type virus (vN1.WT). This demonstrates the importance of NF-κB activation within infected cells for long-term CD8+ T-cell memory and vaccine efficacy. Further, it provides a rationale for deleting N1 from VACV vectors to enhance CD8+ T-cell immunogenicity, while simultaneously reducing virulence to improve vaccine safety. PMID:25382035

Safety mechanism assisted by the repressor of tetracycline (SMART) vaccinia virus vectors for vaccines and therapeutics.

PubMed

Grigg, Patricia; Titong, Allison; Jones, Leslie A; Yilma, Tilahun D; Verardi, Paulo H

2013-09-17

Replication-competent viruses, such as Vaccinia virus (VACV), are powerful tools for the development of oncolytic viral therapies and elicit superior immune responses when used as vaccine and immunotherapeutic vectors. However, severe complications from uncontrolled viral replication can occur, particularly in immunocompromised individuals or in those with other predisposing conditions. VACVs constitutively expressing interferon-γ (IFN-γ) replicate in cell culture indistinguishably from control viruses; however, they replicate in vivo to low or undetectable levels, and are rapidly cleared even in immunodeficient animals. In an effort to develop safe and highly effective replication-competent VACV vectors, we established a system to inducibly express IFN-γ. Our SMART (safety mechanism assisted by the repressor of tetracycline) vectors are designed to express the tetracycline repressor under a constitutive VACV promoter and IFN-γ under engineered tetracycline-inducible promoters. Immunodeficient SCID mice inoculated with VACVs not expressing IFN-γ demonstrated severe weight loss, whereas those given VACVs expressing IFN-γ under constitutive VACV promoters showed no signs of infection. Most importantly, mice inoculated with a VACV expressing the IFN-γ gene under an inducible promoter remained healthy in the presence of doxycycline, but exhibited severe weight loss in the absence of doxycycline. In this study, we developed a safety mechanism for VACV based on the conditional expression of IFN-γ under a tightly controlled tetracycline-inducible VACV promoter for use in vaccines and oncolytic cancer therapies.

Modified Vaccinia virus Ankara-based vaccines in the era of personalized immunotherapy of cancer.

PubMed

Bendjama, Kaïdre; Quemeneur, Eric

2017-09-02

While interest in immunotherapies is renewed by the successful introduction of immune checkpoint blocking agent in the clinic, advances in genome sequencing are opening new possibilities in the design of increasingly personalized vaccines. Personalization of medicine can now be realistically contemplated at the single patient level. Unlike the previous generation of cancer vaccines, neoantigen directed vaccines would target truly specific tumor antigens resulting from acquired tumor genome mutations. Immune response induced by this next generation vaccine would not be subject to self-tolerance and will likely result to enhanced efficacy. Nevertheless, this new technologies can hold to their promises only if sponsors manage to meet several scientific, technical, logistical and regulatory challenges. In particular manufacturers will have to design, manufacture, and deliver to the patient a new pharmaceutical grade in a matters of weeks. In this paper, we briefly review current technologies currently tried at the translation of personalized vaccines and explore the possibilities offered by the Modified Vaccinia virus Ankara in this next wave of cancer vaccines.

A Polymorphism within the Internal Fusion Loop of the Ebola Virus Glycoprotein Modulates Host Cell Entry.

PubMed

Hoffmann, Markus; Crone, Lisa; Dietzel, Erik; Paijo, Jennifer; González-Hernández, Mariana; Nehlmeier, Inga; Kalinke, Ulrich; Becker, Stephan; Pöhlmann, Stefan

2017-05-01

The large scale of the Ebola virus disease (EVD) outbreak in West Africa in 2013-2016 raised the question whether the host cell interactions of the responsible Ebola virus (EBOV) strain differed from those of other ebolaviruses. We previously reported that the glycoprotein (GP) of the virus circulating in West Africa in 2014 (EBOV2014) exhibited reduced ability to mediate entry into two nonhuman primate (NHP)-derived cell lines relative to the GP of EBOV1976. Here, we investigated the molecular determinants underlying the differential entry efficiency. We found that EBOV2014-GP-driven entry into diverse NHP-derived cell lines, as well as human monocyte-derived macrophages and dendritic cells, was reduced compared to EBOV1976-GP, although entry into most human- and all bat-derived cell lines tested was comparable. Moreover, EBOV2014 replication in NHP but not human cells was diminished relative to EBOV1976, suggesting that reduced cell entry translated into reduced viral spread. Mutagenic analysis of EBOV2014-GP and EBOV1976-GP revealed that an amino acid polymorphism in the receptor-binding domain, A82V, modulated entry efficiency in a cell line-independent manner and did not account for the reduced EBOV2014-GP-driven entry into NHP cells. In contrast, polymorphism T544I, located in the internal fusion loop in the GP2 subunit, was found to be responsible for the entry phenotype. These results suggest that position 544 is an important determinant of EBOV infectivity for both NHP and certain human target cells. IMPORTANCE The Ebola virus disease outbreak in West Africa in 2013 entailed more than 10,000 deaths. The scale of the outbreak and its dramatic impact on human health raised the question whether the responsible virus was particularly adept at infecting human cells. Our study shows that an amino acid exchange, A82V, that was acquired during the epidemic and that was not observed in previously circulating viruses, increases viral entry into diverse target cells

The TIM and TAM families of phosphatidylserine receptors mediate dengue virus entry.

PubMed

Meertens, Laurent; Carnec, Xavier; Lecoin, Manuel Perera; Ramdasi, Rasika; Guivel-Benhassine, Florence; Lew, Erin; Lemke, Greg; Schwartz, Olivier; Amara, Ali

2012-10-18

Dengue viruses (DVs) are responsible for the most medically relevant arboviral diseases. However, the molecular interactions mediating DV entry are poorly understood. We determined that TIM and TAM proteins, two receptor families that mediate the phosphatidylserine (PtdSer)-dependent phagocytic removal of apoptotic cells, serve as DV entry factors. Cells poorly susceptible to DV are robustly infected after ectopic expression of TIM or TAM receptors. Conversely, DV infection of susceptible cells is inhibited by anti-TIM or anti-TAM antibodies or knockdown of TIM and TAM expression. TIM receptors facilitate DV entry by directly interacting with virion-associated PtdSer. TAM-mediated infection relies on indirect DV recognition, in which the TAM ligand Gas6 acts as a bridging molecule by binding to PtdSer within the virion. This dual mode of virus recognition by TIM and TAM receptors reveals how DVs usurp the apoptotic cell clearance pathway for infectious entry. Copyright © 2012 Elsevier Inc. All rights reserved.

Inhibition of DAI-dependent necroptosis by the Z-DNA binding domain of the vaccinia virus innate immune evasion protein, E3.

PubMed

Koehler, Heather; Cotsmire, Samantha; Langland, Jeffrey; Kibler, Karen V; Kalman, Daniel; Upton, Jason W; Mocarski, Edward S; Jacobs, Bertram L

2017-10-24

Vaccinia virus (VACV) encodes an innate immune evasion protein, E3, which contains an N-terminal Z-nucleic acid binding (Zα) domain that is critical for pathogenicity in mice. Here we demonstrate that the N terminus of E3 is necessary to inhibit an IFN-primed virus-induced necroptosis. VACV deleted of the Zα domain of E3 (VACV-E3LΔ83N) induced rapid RIPK3-dependent cell death in IFN-treated L929 cells. Cell death was inhibited by the RIPK3 inhibitor, GSK872, and infection with this mutant virus led to phosphorylation and aggregation of MLKL, the executioner of necroptosis. In 293T cells, induction of necroptosis depended on expression of RIPK3 as well as the host-encoded Zα domain-containing DNA sensor, DAI. VACV-E3LΔ83N is attenuated in vivo, and pathogenicity was restored in either RIPK3- or DAI-deficient mice. These data demonstrate that the N terminus of the VACV E3 protein prevents DAI-mediated induction of necroptosis.

Laboratory-acquired vaccinia virus infection in a recently immunized person--Massachusetts, 2013.

PubMed

Hsu, Christopher H; Farland, Julien; Winters, Thomas; Gunn, Julia; Caron, Donna; Evans, Jennifer; Osadebe, Lynda; Bethune, Leon; McCollum, Andrea M; Patel, Nishi; Wilkins, Kimberly; Davidson, Whitni; Petersen, Brett; Barry, M Anita

2015-05-01

On November 26, 2013, the CDC poxvirus laboratory was notified by the Boston Public Health Commission (BPHC) of an inadvertent inoculation of a recently vaccinated (ACAM2000 smallpox vaccine) laboratory worker with wild type vaccinia virus (VACV) Western Reserve. A joint investigation by CDC and BPHC confirmed orthopoxvirus infection in the worker, who had reported a needle stick in his thumb while inoculating a mouse with VACV. He experienced a non-tender, red rash on his arm, diagnosed at a local emergency department as cellulitis. He subsequently developed a necrotic lesion on his thumb, diagnosed as VACV infection. Three weeks after the injury, the thumb lesion was surgically debrided and at 2 months post-injury, the skin lesion had resolved. The investigation confirmed that the infection was the first reported VACV infection in the United States in a laboratory worker vaccinated according to the Advisory Committee on Immunization Practices (ACIP) recommendations. The incident prompted the academic institution to outline biosafety measures for working with biologic agents, such as biosafety training of laboratory personnel, vaccination (if appropriate), and steps in incident reporting. Though vaccination has been shown to be an effective measure in protecting personnel in the laboratory setting, this case report underscores the importance of proper safety measures and incident reporting.

Inhibition of Dengue Virus Entry into Target Cells Using Synthetic Antiviral Peptides

PubMed Central

Alhoot, Mohammed Abdelfatah; Rathinam, Alwin Kumar; Wang, Seok Mui; Manikam, Rishya; Sekaran, Shamala Devi

2013-01-01

Despite the importance of DENV as a human pathogen, there is no specific treatment or protective vaccine. Successful entry into the host cells is necessary for establishing the infection. Recently, the virus entry step has become an attractive therapeutic strategy because it represents a barrier to suppress the onset of the infection. Four putative antiviral peptides were designed to target domain III of DENV-2 E protein using BioMoDroid algorithm. Two peptides showed significant inhibition of DENV when simultaneously incubated as shown by plaque formation assay, RT-qPCR, and Western blot analysis. Both DET4 and DET2 showed significant inhibition of virus entry (84.6% and 40.6% respectively) using micromolar concentrations. Furthermore, the TEM images showed that the inhibitory peptides caused structural abnormalities and alteration of the arrangement of the viral E protein, which interferes with virus binding and entry. Inhibition of DENV entry during the initial stages of infection can potentially reduce the viremia in infected humans resulting in prevention of the progression of dengue fever to the severe life-threatening infection, reduce the infected vector numbers, and thus break the transmission cycle. Moreover these peptides though designed against the conserved region in DENV-2 would have the potential to be active against all the serotypes of dengue and might be considered as Hits to begin designing and developing of more potent analogous peptides that could constitute as promising therapeutic agents for attenuating dengue infection. PMID:23630436

Molecular determinants of dengue virus 2 envelope protein important for virus entry in FcγRIIA-mediated antibody-dependent enhancement of infection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chotiwan, Nunya; Roehrig, John T.; Schlesinger, Jacob J.

Antibody-dependent enhancement (ADE) of infection may cause severe illness in patients suffering a secondary infection by a heterologous dengue virus (DENV) serotype. During ADE of infection, cross-reactive non- or poorly-neutralizing antibodies form infectious virus-Ab complexes with the newly infecting serotype and enhance virus infection by binding to the Fcγ receptors (FcγR) on FcγR-bearing cells. In this study, we determined that molecular determinants of DENV2 envelope protein critical for virus entry during non-ADE infection are also required for ADE infection mediated by FcγRIIA, and binding of virus-Ab complexes with FcγRIIA alone is not sufficient for ADE of infection. The FcγRIIA mainlymore » plays an auxiliary role in concentrating the virus–Ab complex to the cell surface, and other primary cellular receptors are required for virus entry. Understanding the viral entry pathway in ADE of DENV infection will greatly facilitate rational designs of anti-viral therapeutics against severe dengue disease associated with ADE. - Highlights: • KKK305/307/310 in DENV2 E-DIII is critical for virus attachment in ADE and non-ADE infection. • Binding of DENV2–Ab complex with FcγRII alone is not sufficient for virus entry in ADE infection. • Other primary receptors were required for DENV2 internalization during FcγRII–mediated ADE. • G104 and L135 of DENV2 E are critical for virus-mediated membrane fusion. • DENV2 virus-mediated membrane fusion is required for both ADE and non-ADE infection.« less

Attenuated and Replication-Competent Vaccinia Virus Strains M65 and M101 with Distinct Biology and Immunogenicity as Potential Vaccine Candidates against Pathogens

PubMed Central

Sánchez-Sampedro, Lucas; Gómez, Carmen Elena; Mejías-Pérez, Ernesto; Pérez-Jiménez, Eva; Oliveros, Juan Carlos

2013-01-01

Replication-competent poxvirus vectors with an attenuation phenotype and with a high immunogenic capacity of the foreign expressed antigen are being pursued as novel vaccine vectors against different pathogens. In this investigation, we have examined the replication and immunogenic characteristics of two vaccinia virus (VACV) mutants, M65 and M101. These mutants were generated after 65 and 101 serial passages of persistently infected Friend erythroleukemia (FEL) cells. In cultured cells of different origins, the mutants are replication competent and have growth kinetics similar to or slightly reduced in comparison with those of the parental Western Reserve (WR) virus strain. In normal and immune-suppressed infected mice, the mutants showed different levels of attenuation and pathogenicity in comparison with WR and modified vaccinia Ankara (MVA) strains. Wide genome analysis after deep sequencing revealed selected genomic deletions and mutations in a number of viral open reading frames (ORFs). Mice immunized in a DNA prime/mutant boost regimen with viral vectors expressing the LACK (Leishmania homologue for receptors of activated C kinase) antigen of Leishmania infantum showed protection or a delay in the onset of cutaneous leishmaniasis. Protection was similar to that triggered by MVA-LACK. In immunized mice, both polyfunctional CD4+ and CD8+ T cells with an effector memory phenotype were activated by the two mutants, but the DNA-LACK/M65-LACK protocol preferentially induced CD4+ whereas DNA-LACK/M101-LACK preferentially induced CD8+ T cell responses. Altogether, our findings showed the adaptive changes of the WR genome during long-term virus-host cell interaction and how the replication competency of M65 and M101 mutants confers distinct biological properties and immunogenicity in mice compared to those of the MVA strain. These mutants could have applicability for understanding VACV biology and as potential vaccine vectors against pathogens and tumors. PMID

Hazard Characterization of Modified Vaccinia Virus Ankara Vector: What Are the Knowledge Gaps?

PubMed Central

Okeke, Malachy I.; Okoli, Arinze S.; Offor, Collins; Oludotun, Taiwo G.; Tryland, Morten; Bøhn, Thomas; Moens, Ugo

2017-01-01

Modified vaccinia virus Ankara (MVA) is the vector of choice for human and veterinary applications due to its strong safety profile and immunogenicity in vivo. The use of MVA and MVA-vectored vaccines against human and animal diseases must comply with regulatory requirements as they pertain to environmental risk assessment, particularly the characterization of potential adverse effects to humans, animals and the environment. MVA and recombinant MVA are widely believed to pose low or negligible risk to ecosystem health. However, key aspects of MVA biology require further research in order to provide data needed to evaluate the potential risks that may occur due to the use of MVA and MVA-vectored vaccines. The purpose of this paper is to identify knowledge gaps in the biology of MVA and recombinant MVA that are of relevance to its hazard characterization and discuss ongoing and future experiments aimed at providing data necessary to fill in the knowledge gaps. In addition, we presented arguments for the inclusion of uncertainty analysis and experimental investigation of verifiable worst-case scenarios in the environmental risk assessment of MVA and recombinant MVA. These will contribute to improved risk assessment of MVA and recombinant MVA vaccines. PMID:29109380

Hazard Characterization of Modified Vaccinia Virus Ankara Vector: What Are the Knowledge Gaps?

PubMed

Okeke, Malachy I; Okoli, Arinze S; Diaz, Diana; Offor, Collins; Oludotun, Taiwo G; Tryland, Morten; Bøhn, Thomas; Moens, Ugo

2017-10-29

Modified vaccinia virus Ankara (MVA) is the vector of choice for human and veterinary applications due to its strong safety profile and immunogenicity in vivo. The use of MVA and MVA-vectored vaccines against human and animal diseases must comply with regulatory requirements as they pertain to environmental risk assessment, particularly the characterization of potential adverse effects to humans, animals and the environment. MVA and recombinant MVA are widely believed to pose low or negligible risk to ecosystem health. However, key aspects of MVA biology require further research in order to provide data needed to evaluate the potential risks that may occur due to the use of MVA and MVA-vectored vaccines. The purpose of this paper is to identify knowledge gaps in the biology of MVA and recombinant MVA that are of relevance to its hazard characterization and discuss ongoing and future experiments aimed at providing data necessary to fill in the knowledge gaps. In addition, we presented arguments for the inclusion of uncertainty analysis and experimental investigation of verifiable worst-case scenarios in the environmental risk assessment of MVA and recombinant MVA. These will contribute to improved risk assessment of MVA and recombinant MVA vaccines.

Transient dominant host-range selection using Chinese hamster ovary cells to generate marker-free recombinant viral vectors from vaccinia virus.

PubMed

Liu, Liang; Cooper, Tamara; Eldi, Preethi; Garcia-Valtanen, Pablo; Diener, Kerrilyn R; Howley, Paul M; Hayball, John D

2017-04-01

Recombinant vaccinia viruses (rVACVs) are promising antigen-delivery systems for vaccine development that are also useful as research tools. Two common methods for selection during construction of rVACV clones are (i) co-insertion of drug resistance or reporter protein genes, which requires the use of additional selection drugs or detection methods, and (ii) dominant host-range selection. The latter uses VACV variants rendered replication-incompetent in host cell lines by the deletion of host-range genes. Replicative ability is restored by co-insertion of the host-range genes, providing for dominant selection of the recombinant viruses. Here, we describe a new method for the construction of rVACVs using the cowpox CP77 protein and unmodified VACV as the starting material. Our selection system will expand the range of tools available for positive selection of rVACV during vector construction, and it is substantially more high-fidelity than approaches based on selection for drug resistance.

Functional Interplay Between Murine Leukemia Virus Glycogag, Serinc5, and Surface Glycoprotein Governs Virus Entry, with Opposite Effects on Gammaretroviral and Ebolavirus Glycoproteins

PubMed Central

Ahi, Yadvinder S.; Zhang, Shu; Thappeta, Yashna; Denman, Audrey; Feizpour, Amin; Reinhard, Bjoern; Muriaux, Delphine; Fivash, Matthew J.

2016-01-01

ABSTRACT Gammaretroviruses, such as murine leukemia viruses (MLVs), encode, in addition to the canonical Gag, Pol, and Env proteins that will form progeny virus particles, a protein called “glycogag” (glycosylated Gag). MLV glycogag contains the entire Gag sequence plus an 88-residue N-terminal extension. It has recently been reported that glycogag, like the Nef protein of HIV-1, counteracts the antiviral effects of the cellular protein Serinc5. We have found, in agreement with prior work, that glycogag strongly enhances the infectivity of MLVs with some Env proteins but not those with others. In contrast, however, glycogag was detrimental to MLVs carrying Ebolavirus glycoprotein. Glycogag could be replaced, with respect to viral infectivity, by the unrelated S2 protein of equine infectious anemia virus. We devised an assay for viral entry in which virus particles deliver the Cre recombinase into cells, leading to the expression of a reporter. Data from this assay showed that both the positive and the negative effects of glycogag and S2 upon MLV infectivity are exerted at the level of virus entry. Moreover, transfection of the virus-producing cells with a Serinc5 expression plasmid reduced the infectivity and entry capability of MLV carrying xenotropic MLV Env, particularly in the absence of glycogag. Conversely, Serinc5 expression abrogated the negative effects of glycogag upon the infectivity and entry capability of MLV carrying Ebolavirus glycoprotein. As Serinc5 may influence cellular phospholipid metabolism, it seems possible that all of these effects on virus entry derive from changes in the lipid composition of viral membranes. PMID:27879338

Transcription of a vaccinia virus late promoter template: requirement for the product of the A2L intermediate-stage gene.

PubMed Central

Passarelli, A L; Kovacs, G R; Moss, B

1996-01-01

Evidence is presented that a 26-kDa protein encoded by the vaccinia virus A2L open reading frame, originally shown to be one of three intermediate-stage genes that together can transactivate late-stage gene expression in transfection assays (J. G. Keck, C. J. Baldick, and B. Moss, Cell 61:801-809, 1990), is required for in vitro transcription of a template with a late promoter. The critical step in this analysis was the preparation of an extract containing all the required factors except for the A2L protein. This extract was prepared from cells infected with a recombinant vaccinia virus expressing the bacteriophage T7 RNA polymerase in the presence of the DNA synthesis inhibitor cytosine arabinoside and transfected with plasmids containing the two other known transactivator genes, A1L and G8R, under T7 promoter control. Reaction mixtures made with extracts of these cells had background levels of late transcription activity, unless they were supplemented with extracts of cells transfected with the A2L gene. Active transcription mixtures were also made by mixing extracts from three sets of cells, each transfected with a gene (A1L, A2L, or G8R) encoding a separate factor, indicating the absence of any requirement for their coexpression. To minimize the possibility that the A2L protein functions indirectly by activating another viral or cellular protein, this gene was expressed in insect cells by using a baculovirus vector. The partially purified recombinant protein complemented the activity of A2L-deficient cell extracts. Recombinant A1L, A2L, and G8R proteins, all produced in insect cells, together complemented extracts from mammalian cells containing only viral early proteins, concordant with previous in vivo transfection data. PMID:8676468

DNA Packaging Mutant: Repression of the Vaccinia Virus A32 Gene Results in Noninfectious, DNA-Deficient, Spherical, Enveloped Particles

PubMed Central

Cassetti, Maria Cristina; Merchlinsky, Michael; Wolffe, Elizabeth J.; Weisberg, Andrea S.; Moss, Bernard

1998-01-01

The vaccinia virus A32 open reading frame was predicted to encode a protein with a nucleoside triphosphate-binding motif and a mass of 34 kDa. To investigate the role of this protein, we constructed a mutant in which the original A32 gene was replaced by an inducible copy. The recombinant virus, vA32i, has a conditional lethal phenotype: infectious virus formation was dependent on isopropyl-β-d-thiogalactopyranoside (IPTG). Under nonpermissive conditions, the mutant synthesized early- and late-stage viral proteins, as well as viral DNA that was processed into unit-length genomes. Electron microscopy of cells infected in the absence of IPTG revealed normal-appearing crescents and immature virus particles but very few with nucleoids. Instead of brick-shaped mature particles with defined core structures, there were numerous electron-dense, spherical particles. Some of these spherical particles were wrapped with cisternal membranes, analogous to intracellular and extracellular enveloped virions. Mutant viral particles, purified by sucrose density gradient centrifugation, had low infectivity and transcriptional activity, and the majority were spherical and lacked DNA. Nevertheless, the particle preparation contained representative membrane proteins, cleaved and uncleaved core proteins, the viral RNA polymerase, the early transcription factor and several enzymes, suggesting that incorporation of these components is not strictly coupled to DNA packaging. PMID:9621036

Ebola virus entry requires the cholesterol transporter Niemann-Pick C1.

PubMed

Carette, Jan E; Raaben, Matthijs; Wong, Anthony C; Herbert, Andrew S; Obernosterer, Gregor; Mulherkar, Nirupama; Kuehne, Ana I; Kranzusch, Philip J; Griffin, April M; Ruthel, Gordon; Dal Cin, Paola; Dye, John M; Whelan, Sean P; Chandran, Kartik; Brummelkamp, Thijn R

2011-08-24

Infections by the Ebola and Marburg filoviruses cause a rapidly fatal haemorrhagic fever in humans for which no approved antivirals are available. Filovirus entry is mediated by the viral spike glycoprotein (GP), which attaches viral particles to the cell surface, delivers them to endosomes and catalyses fusion between viral and endosomal membranes. Additional host factors in the endosomal compartment are probably required for viral membrane fusion; however, despite considerable efforts, these critical host factors have defied molecular identification. Here we describe a genome-wide haploid genetic screen in human cells to identify host factors required for Ebola virus entry. Our screen uncovered 67 mutations disrupting all six members of the homotypic fusion and vacuole protein-sorting (HOPS) multisubunit tethering complex, which is involved in the fusion of endosomes to lysosomes, and 39 independent mutations that disrupt the endo/lysosomal cholesterol transporter protein Niemann-Pick C1 (NPC1). Cells defective for the HOPS complex or NPC1 function, including primary fibroblasts derived from human Niemann-Pick type C1 disease patients, are resistant to infection by Ebola virus and Marburg virus, but remain fully susceptible to a suite of unrelated viruses. We show that membrane fusion mediated by filovirus glycoproteins and viral escape from the vesicular compartment require the NPC1 protein, independent of its known function in cholesterol transport. Our findings uncover unique features of the entry pathway used by filoviruses and indicate potential antiviral strategies to combat these deadly agents.

Ebola virus requires phosphatidylinositol (3,5) bisphosphate production for efficient viral entry.

PubMed

Qiu, Shirley; Leung, Anders; Bo, Yuxia; Kozak, Robert A; Anand, Sai Priya; Warkentin, Corina; Salambanga, Fabiola D R; Cui, Jennifer; Kobinger, Gary; Kobasa, Darwyn; Côté, Marceline

2018-01-01

For entry, Ebola virus (EBOV) requires the interaction of its viral glycoprotein with the cellular protein Niemann-Pick C1 (NPC1) which resides in late endosomes and lysosomes. How EBOV is trafficked and delivered to NPC1 and whether this is positively regulated during entry remain unclear. Here, we show that the PIKfyve-ArPIKfyve-Sac3 cellular complex, which is involved in the metabolism of phosphatidylinositol (3,5) bisphosphate (PtdIns(3,5)P 2 ), is critical for EBOV infection. Although the expression of all subunits of the complex was required for efficient entry, PIKfyve kinase activity was specifically critical for entry by all pathogenic filoviruses. Inhibition of PIKfyve prevented colocalization of EBOV with NPC1 and led to virus accumulation in intracellular vesicles with characteristics of early endosomes. Importantly, genetically-encoded phosphoinositide probes revealed an increase in PtdIns(3,5)P 2 -positive vesicles in cells during EBOV entry. Taken together, our studies suggest that EBOV requires PtdIns(3,5)P 2 production in cells to promote efficient delivery to NPC1. Copyright © 2017 Elsevier Inc. All rights reserved.

Analysis of Ebola Virus Entry Into Macrophages

PubMed Central

Dahlmann, Franziska; Biedenkopf, Nadine; Babler, Anne; Jahnen-Dechent, Willi; Karsten, Christina B.; Gnirß, Kerstin; Schneider, Heike; Wrensch, Florian; O'Callaghan, Christopher A.; Bertram, Stephanie; Herrler, Georg; Becker, Stephan; Pöhlmann, Stefan; Hofmann-Winkler, Heike

2015-01-01

Ebolaviruses constitute a public health threat, particularly in Central and Western Africa. Host cell factors required for spread of ebolaviruses may serve as targets for antiviral intervention. Lectins, TAM receptor tyrosine kinases (Tyro3, Axl, Mer), T cell immunoglobulin and mucin domain (TIM) proteins, integrins, and Niemann-Pick C1 (NPC1) have been reported to promote entry of ebolaviruses into certain cellular systems. However, the factors used by ebolaviruses to invade macrophages, major viral targets, are poorly defined. Here, we show that mannose-specific lectins, TIM-1 and Axl augment entry into certain cell lines but do not contribute to Ebola virus (EBOV)-glycoprotein (GP)–driven transduction of macrophages. In contrast, expression of Mer, integrin αV, and NPC1 was required for efficient GP-mediated transduction and EBOV infection of macrophages. These results define cellular factors hijacked by EBOV for entry into macrophages and, considering that Mer and integrin αV promote phagocytosis of apoptotic cells, support the concept that EBOV relies on apoptotic mimicry to invade target cells. PMID:25877552

Mosquito Cellular Factors and Functions in Mediating the Infectious entry of Chikungunya Virus

PubMed Central

Lee, Regina Ching Hua; Hapuarachchi, Hapuarachchige Chanditha; Chen, Karen Caiyun; Hussain, Khairunnisa' Mohamed; Chen, Huixin; Low, Swee Ling; Ng, Lee Ching; Lin, Raymond; Ng, Mary Mah-Lee; Chu, Justin Jang Hann

2013-01-01

Chikungunya virus (CHIKV) is an arthropod-borne virus responsible for recent epidemics in the Asia Pacific regions. A customized gene expression microarray of 18,760 transcripts known to target Aedes mosquito genome was used to identify host genes that are differentially regulated during the infectious entry process of CHIKV infection on C6/36 mosquito cells. Several genes such as epsin I (EPN1), epidermal growth factor receptor pathway substrate 15 (EPS15) and Huntingtin interacting protein I (HIP1) were identified to be differentially expressed during CHIKV infection and known to be involved in clathrin-mediated endocytosis (CME). Transmission electron microscopy analyses further revealed the presence of CHIKV particles within invaginations of the plasma membrane, resembling clathrin-coated pits. Characterization of vesicles involved in the endocytic trafficking processes of CHIKV revealed the translocation of the virus particles to the early endosomes and subsequently to the late endosomes and lysosomes. Treatment with receptor-mediated endocytosis inhibitor, monodansylcadaverine and clathrin-associated drug inhibitors, chlorpromazine and dynasore inhibited CHIKV entry, whereas no inhibition was observed with caveolin-related drug inhibitors. Inhibition of CHIKV entry upon treatment with low-endosomal pH inhibitors indicated that low pH is essential for viral entry processes. CHIKV entry by clathrin-mediated endocytosis was validated via overexpression of a dominant-negative mutant of Eps15, in which infectious entry was reduced, while siRNA-based knockdown of genes associated with CME, low endosomal pH and RAB trafficking proteins exhibited significant levels of CHIKV inhibition. This study revealed, for the first time, that the infectious entry of CHIKV into mosquito cells is mediated by the clathrin-dependent endocytic pathway. PMID:23409203

Herpes B Virus Utilizes Human Nectin-1 but Not HVEM or PILRα for Cell-Cell Fusion and Virus Entry

PubMed Central

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

Functional Interplay Between Murine Leukemia Virus Glycogag, Serinc5, and Surface Glycoprotein Governs Virus Entry, with Opposite Effects on Gammaretroviral and Ebolavirus Glycoproteins.

PubMed

Ahi, Yadvinder S; Zhang, Shu; Thappeta, Yashna; Denman, Audrey; Feizpour, Amin; Gummuluru, Suryaram; Reinhard, Bjoern; Muriaux, Delphine; Fivash, Matthew J; Rein, Alan

2016-11-22

Gammaretroviruses, such as murine leukemia viruses (MLVs), encode, in addition to the canonical Gag, Pol, and Env proteins that will form progeny virus particles, a protein called "glycogag" (glycosylated Gag). MLV glycogag contains the entire Gag sequence plus an 88-residue N-terminal extension. It has recently been reported that glycogag, like the Nef protein of HIV-1, counteracts the antiviral effects of the cellular protein Serinc5. We have found, in agreement with prior work, that glycogag strongly enhances the infectivity of MLVs with some Env proteins but not those with others. In contrast, however, glycogag was detrimental to MLVs carrying Ebolavirus glycoprotein. Glycogag could be replaced, with respect to viral infectivity, by the unrelated S2 protein of equine infectious anemia virus. We devised an assay for viral entry in which virus particles deliver the Cre recombinase into cells, leading to the expression of a reporter. Data from this assay showed that both the positive and the negative effects of glycogag and S2 upon MLV infectivity are exerted at the level of virus entry. Moreover, transfection of the virus-producing cells with a Serinc5 expression plasmid reduced the infectivity and entry capability of MLV carrying xenotropic MLV Env, particularly in the absence of glycogag. Conversely, Serinc5 expression abrogated the negative effects of glycogag upon the infectivity and entry capability of MLV carrying Ebolavirus glycoprotein. As Serinc5 may influence cellular phospholipid metabolism, it seems possible that all of these effects on virus entry derive from changes in the lipid composition of viral membranes. Many murine leukemia viruses (MLVs) encode a protein called "glycogag." The function of glycogag is not fully understood, but it can assist HIV-1 replication in the absence of the HIV-1 protein Nef under some circumstances. In turn, Nef counteracts the cellular protein Serinc5. Glycogag enhances the infectivity of MLVs with some but not all

Structure of unliganded HSV gD reveals a mechanism for receptor-mediated activation of virus entry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krummenacher, Claude; Supekar, Vinit M.; Whitbeck, J. Charles

2010-07-19

Herpes simplex virus (HSV) entry into cells requires binding of the envelope glycoprotein D (gD) to one of several cell surface receptors. The 50 C-terminal residues of the gD ectodomain are essential for virus entry, but not for receptor binding. We have determined the structure of an unliganded gD molecule that includes these C-terminal residues. The structure reveals that the C-terminus is anchored near the N-terminal region and masks receptor-binding sites. Locking the C-terminus in the position observed in the crystals by an intramolecular disulfide bond abolished receptor binding and virus entry, demonstrating that this region of gD moves uponmore » receptor binding. Similarly, a point mutant that would destabilize the C-terminus structure was nonfunctional for entry, despite increased affinity for receptors. We propose that a controlled displacement of the gD C-terminus upon receptor binding is an essential feature of HSV entry, ensuring the timely activation of membrane fusion.« less

MVA ROP2 vaccinia virus recombinant as a vaccine candidate for toxoplasmosis.

PubMed

Roque-Reséndiz, J L; Rosales, R; Herion, P

2004-04-01

Toxoplasma gondii is the aetiological agent of toxoplasmosis and is the most frequent and best known of the parasitic diseases. In the United States, a serological survey from the Third National Health and Nutrition Examination Survey found that an estimated 23% of adolescents and adults have laboratory evidence of infection with T. gondii. Although toxoplasmosis is asymptomatic or shows self-limited symptoms in adults, in pregnant women infections can cause severe health problems to the fetus if the parasites are transmitted. Also, in immunodeficient patients, chronic infection with T. gondii can reactivate and produce encephalitis, which is frequently lethal. In addition, in veterinary medicine, T. gondii infection is of economic importance due to abortion and neonatal loss in sheep and goats. Recently, the development of vaccines against toxoplasmosis has progressed considerably. The live attenuated S48 strain of Toxoplasma has been broadly used for veterinary purposes. DNA vaccines containing the full-length of SAG1/P30, ROP2 or ROP1 genes have proved to be a promising candidate to induce protection against toxoplasmosis. Viral vectors have proved to be the best candidates for vaccination in different diseases. A recombinant Herpes virus carrying the ROP2 gene is able to induce protective immunity in cats. In the present work we describe the potential of the MVA ROP2 recombinant vaccinia virus as a vaccine against toxoplasmosis. MVA ROP2 induces antibodies against the ROP2 protein in similar amount and types as the thermo-sensible strain ts-4 of T. gondii, which is able to fully protect mice against challenge with the virulent RH strain of T. gondii. Also, the life-span of mice is increased in MVA ROP2 vaccinated animals. We conclude that MVA ROP2 vaccine can possibly generate an immune response, which could be useful in protection against toxoplasmosis.

A Single Dose of Modified Vaccinia Ankara expressing Ebola Virus Like Particles Protects Nonhuman Primates from Lethal Ebola Virus Challenge.

PubMed

Domi, Arban; Feldmann, Friederike; Basu, Rahul; McCurley, Nathanael; Shifflett, Kyle; Emanuel, Jackson; Hellerstein, Michael S; Guirakhoo, Farshad; Orlandi, Chiara; Flinko, Robin; Lewis, George K; Hanley, Patrick W; Feldmann, Heinz; Robinson, Harriet L; Marzi, Andrea

2018-01-16

Ebola virus (EBOV), isolate Makona, was the causative agent of the West African epidemic devastating predominantly Guinea, Liberia and Sierra Leone from 2013-2016. While several experimental vaccine and treatment approaches have been accelerated through human clinical trials, there is still no approved countermeasure available against this disease. Here, we report the construction and preclinical efficacy testing of a novel recombinant modified vaccinia Ankara (MVA)-based vaccine expressing the EBOV-Makona glycoprotein GP and matrix protein VP40 (MVA-EBOV). GP and VP40 form EBOV-like particles and elicit protective immune responses. In this study, we report 100% protection against lethal EBOV infection in guinea pigs after prime/boost vaccination with MVA-EBOV. Furthermore, this MVA-EBOV protected macaques from lethal disease after a single dose or prime/boost vaccination. The vaccine elicited a variety of antibody responses to both antigens, including neutralizing antibodies and antibodies with antibody-dependent cellular cytotoxic activity specific for GP. This is the first report that a replication-deficient MVA vector can confer full protection against lethal EBOV challenge after a single dose vaccination in macaques.

An update on mechanism of entry of white spot syndrome virus into shrimps.

PubMed

Verma, Arunima Kumar; Gupta, Shipra; Singh, Shivesh Pratap; Nagpure, Naresh Sahebrao

2017-08-01

Host-parasite relationships can be best understood at the level of protein-protein interaction between host and pathogen. Such interactions are instrumental in understanding the important stages of life cycle of pathogen such as adsorption of the pathogen on host surface followed by effective entry of pathogen into the host body, movement of the pathogen across the host cytoplasm to reach the host nucleus and replication of the pathogen within the host. White Spot Disease (WSD) is a havoc for shrimps and till date no effective treatment is available against the disease. Moreover information regarding the mechanism of entry of White Spot Syndrome Virus (WSSV) into shrimps, as well as knowledge about the protein interactions occurring between WSSV and shrimp during viral entry are still at very meagre stage. A cumulative and critically assessed information on various viral-shrimp interactions occurring during viral entry can help to understand the exact pathway of entry of WSSV into the shrimp which in turn can be used to device drugs that can stop the entry of virus into the host. In this context, we highlight various WSSV and shrimp proteins that play role in the entry mechanism along with the description of the interaction between host and pathogen proteins. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modified Vaccinia Virus Ankara Preferentially Targets Antigen Presenting Cells In Vitro, Ex Vivo and In Vivo.

PubMed

Altenburg, Arwen F; van de Sandt, Carolien E; Li, Bobby W S; MacLoughlin, Ronan J; Fouchier, Ron A M; van Amerongen, Geert; Volz, Asisa; Hendriks, Rudi W; de Swart, Rik L; Sutter, Gerd; Rimmelzwaan, Guus F; de Vries, Rory D

2017-08-17

Modified Vaccinia virus Ankara (MVA) is a promising vaccine vector with an excellent safety profile. However, despite extensive pre-clinical and clinical testing, surprisingly little is known about the cellular tropism of MVA, especially in relevant animal species. Here, we performed in vitro, ex vivo and in vivo experiments with recombinant MVA expressing green fluorescent protein (rMVA-GFP). In both human peripheral blood mononuclear cells and mouse lung explants, rMVA-GFP predominantly infected antigen presenting cells. Subsequent in vivo experiments performed in mice, ferrets and non-human primates indicated that preferential targeting of dendritic cells and alveolar macrophages was observed after respiratory administration, although subtle differences were observed between the respective animal species. Following intramuscular injection, rMVA-GFP was detected in interdigitating cells between myocytes, but also in myocytes themselves. These data are important in advancing our understanding of the basis for the immunogenicity of MVA-based vaccines and aid rational vaccine design and delivery strategies.

Real-time PCR to identify variola virus or other human pathogenic orthopox viruses.

PubMed

Scaramozzino, Natale; Ferrier-Rembert, Audrey; Favier, Anne-Laure; Rothlisberger, Corinne; Richard, Stéphane; Crance, Jean-Marc; Meyer, Hermann; Garin, Daniel

2007-04-01

Variola virus (family Poxviridae, genus Orthopoxvirus) and the closely related cowpox, vaccinia, and monkeypox viruses can infect humans. Efforts are mounting to replenish the smallpox vaccine stocks, optimize diagnostic methods for poxviruses, and develop new antivirals against smallpox, because it is feared that variola virus might be used as a weapon of bioterrorism. We developed an assay for the detection of variola virus DNA. The assay is based on TaqMan chemistry targeting the 14-kD protein gene. For the 1st stage of the assay we used genus consensus primers and a mixture of 2 probes (14-kD POX and 14-kD VAR) spanning the 14-kD protein-encoding gene for detection of all human pathogenic orthopoxviruses. We then tested positive samples with the specific orthopoxvirus-specific probe 14-kD POX to identify monkeypox, cowpox, and vaccinia viruses and with the 14-kD VAR probe to identify variola viruses. The assay was established on 4 different PCR cycler platforms. It was assessed in a study with 85 different orthopoxvirus species and strains that included variola, camelpox, cowpox, monkeypox, and vaccinia viruses at concentrations ranging from 100 ng/L to 1 microg/L. The assay detected as little as 0.05 fg of DNA, corresponding to 25 copies of DNA, and enabled differentiation of variola virus from the other orthopoxviruses. This real-time PCR assay provides a rapid method for the early detection and differentiation of smallpox and other human pathogenic orthopoxvirus infections.

Tyro3 Family-Mediated Cell Entry of Ebola and Marburg Viruses

PubMed Central

Shimojima, Masayuki; Takada, Ayato; Ebihara, Hideki; Neumann, Gabriele; Fujioka, Kouki; Irimura, Tatsuro; Jones, Steven; Feldmann, Heinz; Kawaoka, Yoshihiro

2006-01-01

Filoviruses, represented by the genera Ebolavirus and Marburgvirus, cause a lethal hemorrhagic fever in humans and in nonhuman primates. Although filovirus can replicate in various tissues or cell types in these animals, the molecular mechanisms of its broad tropism remain poorly understood. Here we show the involvement of members of the Tyro3 receptor tyrosine kinase family—Axl, Dtk, and Mer—in cell entry of filoviruses. Ectopic expression of these family members in lymphoid cells, which otherwise are highly resistant to filovirus infection, enhanced infection by pseudotype viruses carrying filovirus glycoproteins on their envelopes. This enhancement was reduced by antibodies to Tyro3 family members, Gas6 ligand, or soluble ectodomains of the members. Live Ebola viruses infected both Axl- and Dtk-expressing cells more efficiently than control cells. Antibody to Axl inhibited infection of pseudotype viruses in a number of Axl-positive cell lines. These results implicate each Tyro3 family member as a cell entry factor in filovirus infection. PMID:17005688

Smallpox virus plaque phenotypes: genetic, geographical and case fatality relationships.

PubMed

Olson, Victoria A; Karem, Kevin L; Smith, Scott K; Hughes, Christine M; Damon, Inger K

2009-04-01

Smallpox (infection with Orthopoxvirus variola) remains a feared illness more than 25 years after its eradication. Historically, case-fatality rates (CFRs) varied between outbreaks (<1 to approximately 40 %), the reasons for which are incompletely understood. The extracellular enveloped virus (EEV) form of orthopoxvirus progeny is hypothesized to disseminate infection. Investigations with the closely related Orthopoxvirus vaccinia have associated increased comet formation (EEV production) with increased mouse mortality (pathogenicity). Other vaccinia virus genetic manipulations which affect EEV production inconsistently support this association. However, antisera against vaccinia virus envelope protect mice from lethal challenge, further supporting a critical role for EEV in pathogenicity. Here, we show that the increased comet formation phenotypes of a diverse collection of variola viruses associate with strain phylogeny and geographical origin, but not with increased outbreak-related CFRs; within clades, there may be an association of plaque size with CFR. The mechanisms for variola virus pathogenicity probably involves multiple host and pathogen factors.

Vpx complementation of 'non-macrophage tropic' R5 viruses reveals robust entry of infectious HIV-1 cores into macrophages.

PubMed

Mlcochova, Petra; Watters, Sarah A; Towers, Greg J; Noursadeghi, Mahdad; Gupta, Ravindra K

2014-03-21

It is now known that clinically derived viruses are most commonly R5 tropic with very low infectivity in macrophages. As these viruses utilize CD4 inefficiently, defective entry has been assumed to be the dominant restriction. The implication is that macrophages are not an important reservoir for the majority of circulating viruses. Macrophage infection by clinical transmitted/founder isolates was 10-100 and 30-450 fold less efficient as compared to YU-2 and BaL respectively. Vpx complementation augmented macrophage infection by non-macrophage tropic viruses to the level of infectivity observed for YU-2 in the absence of Vpx. Augmentation was evident even when Vpx was provided 24 hours post-infection. The entry defect was measured as 2.5-5 fold, with a further 3.5-10 fold block at strong stop and subsequent stages of reverse transcription as compared to YU-2. The overall block to infection was critically dependent on the mechanism of entry as demonstrated by rescue of infection after pseudotyping with VSV-G envelope. Reverse transcription in macrophages could not be enhanced using a panel of cytokines or lipopolysaccharide (LPS). Although the predominant block to clinical transmitted/founder viruses is post-entry, infectivity is determined by Env-CD4 interactions and can be rescued with VSV-G pseudotyping. This suggests a functional link between the optimal entry pathway taken by macrophage tropic viruses and downstream events required for reverse transcription. Consistent with a predominantly post-entry block, replication of R5 using viruses can be greatly enhanced by Vpx. We conclude therefore that entry is not the limiting step and that macrophages represent clinically relevant reservoirs for 'non-macrophage tropic' viruses.

Polyphenols Inhibit Hepatitis C Virus Entry by a New Mechanism of Action.

PubMed

Calland, Noémie; Sahuc, Marie-Emmanuelle; Belouzard, Sandrine; Pène, Véronique; Bonnafous, Pierre; Mesalam, Ahmed Atef; Deloison, Gaspard; Descamps, Véronique; Sahpaz, Sevser; Wychowski, Czeslaw; Lambert, Olivier; Brodin, Priscille; Duverlie, Gilles; Meuleman, Philip; Rosenberg, Arielle R; Dubuisson, Jean; Rouillé, Yves; Séron, Karin

2015-10-01

Despite the validation of direct-acting antivirals for hepatitis C treatment, the discovery of new compounds with different modes of action may still be of importance for the treatment of special patient populations. We recently identified a natural molecule, epigallocatechin-3-gallate (EGCG), as an inhibitor of hepatitis C virus (HCV) targeting the viral particle. The aim of this work was to discover new natural compounds with higher anti-HCV activity than that of EGCG and determine their mode of action. Eight natural molecules with structure similarity to EGCG were selected. HCV JFH1 in cell culture and HCV pseudoparticle systems were used to determine the antiviral activity and mechanism of action of the compounds. We identified delphinidin, a polyphenol belonging to the anthocyanidin family, as a new inhibitor of HCV entry. Delphinidin inhibits HCV entry in a pangenotypic manner by acting directly on the viral particle and impairing its attachment to the cell surface. Importantly, it is also active against HCV in primary human hepatocytes, with no apparent cytotoxicity and in combination with interferon and boceprevir in cell culture. Different approaches showed that neither aggregation nor destruction of the particle occurred. Cryo-transmission electron microscopy observations of HCV pseudoparticles treated with delphinidin or EGCG showed a bulge on particles that was not observed under control conditions. In conclusion, EGCG and delphinidin inhibit HCV entry by a new mechanism, i.e., alteration of the viral particle structure that impairs its attachment to the cell surface. In this article, we identify a new inhibitor of hepatitis C virus (HCV) infection, delphinidin, that prevents HCV entry. This natural compound, a plant pigment responsible for the blue-purple color of flowers and berries, belongs to the flavonoid family, like the catechin EGCG, the major component present in green tea extract, which is also an inhibitor of HCV entry. We studied the mode of

Protective Efficacy of the Conserved NP, PB1, and M1 Proteins as Immunogens in DNA- and Vaccinia Virus-Based Universal Influenza A Virus Vaccines in Mice

PubMed Central

Wang, Wenling; Li, Renqing; Deng, Yao; Lu, Ning; Chen, Hong; Meng, Xin; Wang, Wen; Wang, Xiuping; Yan, Kexia; Qi, Xiangrong; Zhang, Xiangmin; Xin, Wei; Lu, Zhenhua; Li, Xueren; Bian, Tao; Gao, Yingying; Tan, Wenjie

2015-01-01

The conventional hemagglutinin (HA)- and neuraminidase (NA)-based influenza vaccines need to be updated most years and are ineffective if the glycoprotein HA of the vaccine strains is a mismatch with that of the epidemic strain. Universal vaccines targeting conserved viral components might provide cross-protection and thus complement and improve conventional vaccines. In this study, we generated DNA plasmids and recombinant vaccinia viruses expressing the conserved proteins nucleoprotein (NP), polymerase basic 1 (PB1), and matrix 1 (M1) from influenza virus strain A/Beijing/30/95 (H3N2). BALB/c mice were immunized intramuscularly with a single vaccine based on NP, PB1, or M1 alone or a combination vaccine based on all three antigens and were then challenged with lethal doses of the heterologous influenza virus strain A/PR/8/34 (H1N1). Vaccines based on NP, PB1, and M1 provided complete or partial protection against challenge with 1.7 50% lethal dose (LD50) of PR8 in mice. Of the three antigens, NP-based vaccines induced protection against 5 LD50 and 10 LD50 and thus exhibited the greatest protective effect. Universal influenza vaccines based on the combination of NP, PB1, and M1 induced a strong immune response and thus might be an alternative approach to addressing future influenza virus pandemics. PMID:25834017

Characterization of ectromelia virus deficient in EVM036, the homolog of vaccinia virus F13L, and its application for rapid generation of recombinant viruses.

PubMed

Roscoe, Felicia; Xu, Ren-Huan; Sigal, Luis J

2012-12-01

The orthopoxvirus (OPV) vaccinia virus (VACV) requires an intact F13L gene to produce enveloped virions (EV) and to form plaques in cell monolayers. Simultaneous introduction of an exogenous gene and F13L into F13L-deficient VACV results in expression of the foreign gene and restoration of plaque size. This is used as a method to rapidly generate VACV recombinants without the need for drug selection. However, whether other OPVs require the orthologs of F13L to generate EV and form plaques, whether F13L orthologs and EV are important for OPV pathogenesis in natural hosts, and whether a system based on F13L ortholog deficiency can be used to generate recombinant OPVs other than VACV have not been reported. The F13L ortholog in ectromelia virus (ECTV), the agent of mousepox, is EVM036. We show that ECTV lacking EVM036 formed small plaques and was highly attenuated in vivo but still induced strong antibody responses. Reintroduction of EVM036 in tandem with the DsRed gene resulted in a virus that expressed DsRed in infected cells but was indistinguishable from wild-type ECTV in terms of plaque size and in vivo virulence. Thus, our data show that, like F13L in VACV, EVM036 is required for ECTV plaque formation and that EVM036 and EV are important for ECTV virulence. Our experiments also suggest that OPVs deficient in F13L orthologs could serve as safer anti-OPV vaccines. Further, our results demonstrate that ECTV deficient in EVM036 can be exploited for the rapid generation of fully virulent ECTV expressing foreign genes of interest.

Variola virus F1L is a Bcl-2-like protein that unlike its vaccinia virus counterpart inhibits apoptosis independent of Bim

PubMed Central

Marshall, B; Puthalakath, H; Caria, S; Chugh, S; Doerflinger, M; Colman, P M; Kvansakul, M

2015-01-01

Subversion of host cell apoptosis is an important survival strategy for viruses to ensure their own proliferation and survival. Certain viruses express proteins homologous in sequence, structure and function to mammalian pro-survival B-cell lymphoma 2 (Bcl-2) proteins, which prevent rapid clearance of infected host cells. In vaccinia virus (VV), the virulence factor F1L was shown to be a potent inhibitor of apoptosis that functions primarily be engaging pro-apoptotic Bim. Variola virus (VAR), the causative agent of smallpox, harbors a homolog of F1L of unknown function. We show that VAR F1L is a potent inhibitor of apoptosis, and unlike all other characterized anti-apoptotic Bcl-2 family members lacks affinity for the Bim Bcl-2 homology 3 (BH3) domain. Instead, VAR F1L engages Bid BH3 as well as Bak and Bax BH3 domains. Unlike its VV homolog, variola F1L only protects against Bax-mediated apoptosis in cellular assays. Crystal structures of variola F1L bound to Bid and Bak BH3 domains reveal that variola F1L forms a domain-swapped Bcl-2 fold, which accommodates Bid and Bak BH3 in the canonical Bcl-2-binding groove, in a manner similar to VV F1L. Despite the observed conservation of structure and sequence, variola F1L inhibits apoptosis using a startlingly different mechanism compared with its VV counterpart. Our results suggest that unlike during VV infection, Bim neutralization may not be required during VAR infection. As molecular determinants for the human-specific tropism of VAR remain essentially unknown, identification of a different mechanism of action and utilization of host factors used by a VAR virulence factor compared with its VV homolog suggest that studying VAR directly may be essential to understand its unique tropism. PMID:25766319

Variola virus F1L is a Bcl-2-like protein that unlike its vaccinia virus counterpart inhibits apoptosis independent of Bim.

PubMed

Marshall, B; Puthalakath, H; Caria, S; Chugh, S; Doerflinger, M; Colman, P M; Kvansakul, M

2015-03-12

Subversion of host cell apoptosis is an important survival strategy for viruses to ensure their own proliferation and survival. Certain viruses express proteins homologous in sequence, structure and function to mammalian pro-survival B-cell lymphoma 2 (Bcl-2) proteins, which prevent rapid clearance of infected host cells. In vaccinia virus (VV), the virulence factor F1L was shown to be a potent inhibitor of apoptosis that functions primarily be engaging pro-apoptotic Bim. Variola virus (VAR), the causative agent of smallpox, harbors a homolog of F1L of unknown function. We show that VAR F1L is a potent inhibitor of apoptosis, and unlike all other characterized anti-apoptotic Bcl-2 family members lacks affinity for the Bim Bcl-2 homology 3 (BH3) domain. Instead, VAR F1L engages Bid BH3 as well as Bak and Bax BH3 domains. Unlike its VV homolog, variola F1L only protects against Bax-mediated apoptosis in cellular assays. Crystal structures of variola F1L bound to Bid and Bak BH3 domains reveal that variola F1L forms a domain-swapped Bcl-2 fold, which accommodates Bid and Bak BH3 in the canonical Bcl-2-binding groove, in a manner similar to VV F1L. Despite the observed conservation of structure and sequence, variola F1L inhibits apoptosis using a startlingly different mechanism compared with its VV counterpart. Our results suggest that unlike during VV infection, Bim neutralization may not be required during VAR infection. As molecular determinants for the human-specific tropism of VAR remain essentially unknown, identification of a different mechanism of action and utilization of host factors used by a VAR virulence factor compared with its VV homolog suggest that studying VAR directly may be essential to understand its unique tropism.

Giants among larges: how gigantism impacts giant virus entry into amoebae.

PubMed

Rodrigues, Rodrigo Araújo Lima; Abrahão, Jônatas Santos; Drumond, Betânia Paiva; Kroon, Erna Geessien

2016-06-01

The proposed order Megavirales comprises the nucleocytoplasmic large DNA viruses (NCLDV), infecting a wide range of hosts. Over time, they co-evolved with different host cells, developing various strategies to penetrate them. Mimiviruses and other giant viruses enter cells through phagocytosis, while Marseillevirus and other large viruses explore endocytosis and macropinocytosis. These differing strategies might reflect the evolution of those viruses. Various scenarios have been proposed for the origin and evolution of these viruses, presenting one of the most enigmatic issues to surround these microorganisms. In this context, we believe that giant viruses evolved independently by massive gene/size gain, exploring the phagocytic pathway of entry into amoebas. In response to gigantism, hosts developed mechanisms to evade these parasites. Copyright © 2016 Elsevier Ltd. All rights reserved.

African swine fever virus infects macrophages, the natural host cells, via clathrin- and cholesterol-dependent endocytosis.

PubMed

Galindo, Inmaculada; Cuesta-Geijo, Miguel Angel; Hlavova, Karolina; Muñoz-Moreno, Raquel; Barrado-Gil, Lucía; Dominguez, Javier; Alonso, Covadonga

2015-03-16

The main cellular target for African swine fever virus (ASFV) is the porcine macrophage. However, existing data about the early phases of infection were previously characterized in non-leukocyte cells such as Vero cells. Here, we report that ASFV enters the natural host cell using dynamin-dependent and clathrin-mediated endocytosis. This pathway is strongly pH-dependent during the first steps of infection in porcine macrophages. We investigated the effect of drugs inhibiting several endocytic pathways in macrophages and compared ASFV with vaccinia virus (VV), which apparently involves different entry pathways. The presence of cholesterol in cellular membranes was found to be essential for a productive ASFV infection while actin-dependent endocytosis and the participation of phosphoinositide-3-kinase (PI3K) activity were other cellular factors required in the process of viral entry. These findings improved our understanding of the ASFV interactions with macrophages that allow for successful viral replication. Copyright © 2015 Elsevier B.V. All rights reserved.

Analysis of Ebola Virus Entry Into Macrophages.

PubMed

Dahlmann, Franziska; Biedenkopf, Nadine; Babler, Anne; Jahnen-Dechent, Willi; Karsten, Christina B; Gnirß, Kerstin; Schneider, Heike; Wrensch, Florian; O'Callaghan, Christopher A; Bertram, Stephanie; Herrler, Georg; Becker, Stephan; Pöhlmann, Stefan; Hofmann-Winkler, Heike

2015-10-01

Ebolaviruses constitute a public health threat, particularly in Central and Western Africa. Host cell factors required for spread of ebolaviruses may serve as targets for antiviral intervention. Lectins, TAM receptor tyrosine kinases (Tyro3, Axl, Mer), T cell immunoglobulin and mucin domain (TIM) proteins, integrins, and Niemann-Pick C1 (NPC1) have been reported to promote entry of ebolaviruses into certain cellular systems. However, the factors used by ebolaviruses to invade macrophages, major viral targets, are poorly defined. Here, we show that mannose-specific lectins, TIM-1 and Axl augment entry into certain cell lines but do not contribute to Ebola virus (EBOV)-glycoprotein (GP)-driven transduction of macrophages. In contrast, expression of Mer, integrin αV, and NPC1 was required for efficient GP-mediated transduction and EBOV infection of macrophages. These results define cellular factors hijacked by EBOV for entry into macrophages and, considering that Mer and integrin αV promote phagocytosis of apoptotic cells, support the concept that EBOV relies on apoptotic mimicry to invade target cells. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

Variola virus immune evasion proteins.

PubMed

Dunlop, Lance R; Oehlberg, Katherine A; Reid, Jeremy J; Avci, Dilek; Rosengard, Ariella M

2003-09-01

Variola virus, the causative agent of smallpox, encodes approximately 200 proteins. Over 80 of these proteins are located in the terminal regions of the genome, where proteins associated with host immune evasion are encoded. To date, only two variola proteins have been characterized. Both are located in the terminal regions and demonstrate immunoregulatory functions. One protein, the smallpox inhibitor of complement enzymes (SPICE), is homologous to a vaccinia virus virulence factor, the vaccinia virus complement-control protein (VCP), which has been found experimentally to be expressed early in the course of vaccinia infection. Both SPICE and VCP are similar in structure and function to the family of mammalian complement regulatory proteins, which function to prevent inadvertent injury to adjacent cells and tissues during complement activation. The second variola protein is the variola virus high-affinity secreted chemokine-binding protein type II (CKBP-II, CBP-II, vCCI), which binds CC-chemokine receptors. The vaccinia homologue of CKBP-II is secreted both early and late in infection. CKBP-II proteins are highly conserved among orthopoxviruses, sharing approximately 85% homology, but are absent in eukaryotes. This characteristic sets it apart from other known virulence factors in orthopoxviruses, which share sequence homology with known mammalian immune regulatory gene products. Future studies of additional variola proteins may help illuminate factors associated with its virulence, pathogenesis and strict human tropism. In addition, these studies may also assist in the development of targeted therapies for the treatment of both smallpox and human immune-related diseases.

Three-Year Durability of Immune Responses Induced by HIV-DNA and HIV-Modified Vaccinia Virus Ankara and Effect of a Late HIV-Modified Vaccinia Virus Ankara Boost in Tanzanian Volunteers.

PubMed

Joachim, Agricola; Munseri, Patricia J; Nilsson, Charlotta; Bakari, Muhammad; Aboud, Said; Lyamuya, Eligius F; Tecleab, Teghesti; Liakina, Valentina; Scarlatti, Gabriella; Robb, Merlin L; Earl, Patricia L; Moss, Bernard; Wahren, Britta; Mhalu, Fred; Ferrari, Guido; Sandstrom, Eric; Biberfeld, Gunnel

2017-08-01

We explored the duration of immune responses and the effect of a late third HIV-modified vaccinia virus Ankara (MVA) boost in HIV-DNA primed and HIV-MVA boosted Tanzanian volunteers. Twenty volunteers who had previously received three HIV-DNA and two HIV-MVA immunizations were given a third HIV-MVA immunization 3 years after the second HIV-MVA boost. At the time of the third HIV-MVA, 90% of the vaccinees had antibodies to HIV-1 subtype C gp140 (median titer 200) and 85% to subtype B gp160 (median titer 100). The majority of vaccinees had detectable antibody-dependent cellular cytotoxicity (ADCC)-mediating antibodies, 70% against CRF01_AE virus-infected cells (median titer 239) and 84% against CRF01_AE gp120-coated cells (median titer 499). A high proportion (74%) of vaccinees had IFN-γ ELISpot responses, 63% to Gag and 42% to Env, 3 years after the second HIV-MVA boost. After the third HIV-MVA, there was an increase in Env-binding antibodies and ADCC-mediating antibodies relative to the response seen at the time of the third HIV-MVA vaccination, p < .0001 and p < .05, respectively. The frequency of IFN-γ ELISpot responses increased to 95% against Gag or Env and 90% to both Gag and Env, p = .064 and p = .002, respectively. In conclusion, the HIV-DNA prime/HIV-MVA boost regimen elicited potent antibody and cellular immune responses with remarkable durability, and a third HIV-MVA immunization significantly boosted both antibody and cellular immune responses relative to the levels detected at the time of the third HIV-MVA, but not to higher levels than after the second HIV-MVA.

GRP78 Is an Important Host Factor for Japanese Encephalitis Virus Entry and Replication in Mammalian Cells.

PubMed

Nain, Minu; Mukherjee, Sriparna; Karmakar, Sonali Porey; Paton, Adrienne W; Paton, James C; Abdin, M Z; Basu, Anirban; Kalia, Manjula; Vrati, Sudhanshu

2017-03-15

Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, is the leading cause of viral encephalitis in Southeast Asia with potential to become a global pathogen. Here, we identify glucose-regulated protein 78 (GRP78) as an important host protein for virus entry and replication. Using the plasma membrane fractions from mouse neuronal (Neuro2a) cells, mass spectroscopy analysis identified GRP78 as a protein interacting with recombinant JEV envelope protein domain III. GRP78 was found to be expressed on the plasma membranes of Neuro2a cells, mouse primary neurons, and human epithelial Huh-7 cells. Antibodies against GRP78 significantly inhibited JEV entry in all three cell types, suggesting an important role of the protein in virus entry. Depletion of GRP78 by small interfering RNA (siRNA) significantly blocked JEV entry into Neuro2a cells, further supporting its role in virus uptake. Immunofluorescence studies showed extensive colocalization of GRP78 with JEV envelope protein in virus-infected cells. This interaction was also confirmed by immunoprecipitation studies. Additionally, GRP78 was shown to have an important role in JEV replication, as treatment of cells post-virus entry with subtilase cytotoxin that specifically cleaved GRP78 led to a substantial reduction in viral RNA replication and protein synthesis, resulting in significantly reduced extracellular virus titers. Our results indicate that GRP78, an endoplasmic reticulum chaperon of the HSP70 family, is a novel host factor involved at multiple steps of the JEV life cycle and could be a potential therapeutic target. IMPORTANCE Recent years have seen a rapid spread of mosquito-borne diseases caused by flaviviruses. The flavivirus family includes West Nile, dengue, Japanese encephalitis, and Zika viruses, which are major threats to public health with potential to become global pathogens. JEV is the major cause of viral encephalitis in several parts of Southeast Asia, affecting a predominantly pediatric

Vaccinia virus-free rescue of fluorescent replication-defective vesicular stomatitis virus and pseudotyping with Puumala virus glycoproteins for use in neutralization tests.

PubMed

Paneth Iheozor-Ejiofor, Rommel; Levanov, Lev; Hepojoki, Jussi; Strandin, Tomas; Lundkvist, Åke; Plyusnin, Alexander; Vapalahti, Olli

2016-05-01

Puumala virus (PUUV) grows slowly in cell culture. To study antigenic properties of PUUV, an amenable method for their expression would be beneficial. To achieve this, a replication-defective recombinant vesicular stomatitis virus, rVSVΔG*EGFP, was rescued using BSRT7/5 and encephalomyocarditis virus (EMCV) internal ribosomal entry site (IRES)-enabled rescue plasmids. Using these particles, pseudotypes bearing PUUV Sotkamo strain glycoproteins were produced, with titres in the range 105-108, and were used in pseudotype focus reduction neutralization tests (pFRNTs) with neutralizing monoclonal antibodies and patient sera. The results were compared with those from orthodox focus reduction neutralization tests (oFRNTs) using native PUUV with the same samples and showed a strong positive correlation (rs = 0.82) between the methods. While developing the system we identified three amino acids which were mutated in the Vero E6 cell culture adapted PUUV prototype Sotkamo strain sequence, and changing these residues was critical for expression and neutralizing antibody binding of PUUV glycoproteins.

Inhibition of Ebola and Marburg Virus Entry by G Protein-Coupled Receptor Antagonists.

PubMed

Cheng, Han; Lear-Rooney, Calli M; Johansen, Lisa; Varhegyi, Elizabeth; Chen, Zheng W; Olinger, Gene G; Rong, Lijun

2015-10-01

Filoviruses, consisting of Ebola virus (EBOV) and Marburg virus (MARV), are among the most lethal infectious threats to mankind. Infections by these viruses can cause severe hemorrhagic fevers in humans and nonhuman primates with high mortality rates. Since there is currently no vaccine or antiviral therapy approved for humans, there is an urgent need to develop prophylactic and therapeutic options for use during filoviral outbreaks and bioterrorist attacks. One of the ideal targets against filoviral infection and diseases is at the entry step, which is mediated by the filoviral glycoprotein (GP). In this report, we screened a chemical library of small molecules and identified numerous inhibitors, which are known G protein-coupled receptor (GPCR) antagonists targeting different GPCRs, including histamine receptors, 5-HT (serotonin) receptors, muscarinic acetylcholine receptor, and adrenergic receptor. These inhibitors can effectively block replication of both infectious EBOV and MARV, indicating a broad antiviral activity of the GPCR antagonists. The time-of-addition experiment and microscopic studies suggest that GPCR antagonists block filoviral entry at a step following the initial attachment but prior to viral/cell membrane fusion. These results strongly suggest that GPCRs play a critical role in filoviral entry and GPCR antagonists can be developed as an effective anti-EBOV/MARV therapy. Infection of Ebola virus and Marburg virus can cause severe illness in humans with a high mortality rate, and currently there is no FDA-approved vaccine or therapeutic treatment available. The 2013-2015 epidemic in West Africa underscores a lack of our understanding in the infection and pathogenesis of these viruses and the urgency of drug discovery and development. In this study, we have identified numerous inhibitors that are known G protein-coupled receptor (GPCR) antagonists targeting different GPCRs. These inhibitors can effectively block replication of both infectious

Inhibition of Ebola and Marburg Virus Entry by G Protein-Coupled Receptor Antagonists

PubMed Central

Cheng, Han; Lear-Rooney, Calli M.; Johansen, Lisa; Varhegyi, Elizabeth; Chen, Zheng W.; Olinger, Gene G.

2015-01-01

ABSTRACT Filoviruses, consisting of Ebola virus (EBOV) and Marburg virus (MARV), are among the most lethal infectious threats to mankind. Infections by these viruses can cause severe hemorrhagic fevers in humans and nonhuman primates with high mortality rates. Since there is currently no vaccine or antiviral therapy approved for humans, there is an urgent need to develop prophylactic and therapeutic options for use during filoviral outbreaks and bioterrorist attacks. One of the ideal targets against filoviral infection and diseases is at the entry step, which is mediated by the filoviral glycoprotein (GP). In this report, we screened a chemical library of small molecules and identified numerous inhibitors, which are known G protein-coupled receptor (GPCR) antagonists targeting different GPCRs, including histamine receptors, 5-HT (serotonin) receptors, muscarinic acetylcholine receptor, and adrenergic receptor. These inhibitors can effectively block replication of both infectious EBOV and MARV, indicating a broad antiviral activity of the GPCR antagonists. The time-of-addition experiment and microscopic studies suggest that GPCR antagonists block filoviral entry at a step following the initial attachment but prior to viral/cell membrane fusion. These results strongly suggest that GPCRs play a critical role in filoviral entry and GPCR antagonists can be developed as an effective anti-EBOV/MARV therapy. IMPORTANCE Infection of Ebola virus and Marburg virus can cause severe illness in humans with a high mortality rate, and currently there is no FDA-approved vaccine or therapeutic treatment available. The 2013-2015 epidemic in West Africa underscores a lack of our understanding in the infection and pathogenesis of these viruses and the urgency of drug discovery and development. In this study, we have identified numerous inhibitors that are known G protein-coupled receptor (GPCR) antagonists targeting different GPCRs. These inhibitors can effectively block replication of

Studies of Ebola Virus Glycoprotein-Mediated Entry and Fusion by Using Pseudotyped Human Immunodeficiency Virus Type 1 Virions: Involvement of Cytoskeletal Proteins and Enhancement by Tumor Necrosis Factor Alpha

PubMed Central

Yonezawa, Akihito; Cavrois, Marielle; Greene, Warner C.

2005-01-01

The Ebola filoviruses are aggressive pathogens that cause severe and often lethal hemorrhagic fever syndromes in humans and nonhuman primates. To date, no effective therapies have been identified. To analyze the entry and fusion properties of Ebola virus, we adapted a human immunodeficiency virus type 1 (HIV-1) virion-based fusion assay by substituting Ebola virus glycoprotein (GP) for the HIV-1 envelope. Fusion was detected by cleavage of the fluorogenic substrate CCF2 by β-lactamase-Vpr incorporated into virions and released as a result of virion fusion. Entry and fusion induced by the Ebola virus GP occurred with much slower kinetics than with vesicular stomatitis virus G protein (VSV-G) and were blocked by depletion of membrane cholesterol and by inhibition of vesicular acidification with bafilomycin A1. These properties confirmed earlier studies and validated the assay for exploring other properties of Ebola virus GP-mediated entry and fusion. Entry and fusion of Ebola virus GP pseudotypes, but not VSV-G or HIV-1 Env pseudotypes, were impaired in the presence of the microtubule-disrupting agent nocodazole but were enhanced in the presence of the microtubule-stabilizing agent paclitaxel (Taxol). Agents that impaired microfilament function, including cytochalasin B, cytochalasin D, latrunculin A, and jasplakinolide, also inhibited Ebola virus GP-mediated entry and fusion. Together, these findings suggest that both microtubules and microfilaments may play a role in the effective trafficking of vesicles containing Ebola virions from the cell surface to the appropriate acidified vesicular compartment where fusion occurs. In terms of Ebola virus GP-mediated entry and fusion to various target cells, primary macrophages proved highly sensitive, while monocytes from the same donors displayed greatly reduced levels of entry and fusion. We further observed that tumor necrosis factor alpha, which is released by Ebola virus-infected monocytes/macrophages, enhanced Ebola

Amiodarone affects Ebola virus binding and entry into target cells.

PubMed

Salata, Cristiano; Munegato, Denis; Martelli, Francesco; Parolin, Cristina; Calistri, Arianna; Baritussio, Aldo; Palù, Giorgio

2018-03-02

Ebola Virus Disease is one of the most lethal transmissible infections characterized by a high fatality rate. Several research studies have aimed to identify effective antiviral agents. Amiodarone, a drug used for the treatment of arrhythmias, has been shown to inhibit filovirus infection in vitro by acting at the early step of the viral replication cycle. Here we demonstrate that amiodarone reduces virus binding to target cells and slows down the progression of the viral particles along the endocytic pathway. Overall our data support the notion that amiodarone interferes with Ebola virus infection by affecting cellular pathways/targets involved in the viral entry process.

Mucosal Immunization with Newcastle Disease Virus Vector Coexpressing HIV-1 Env and Gag Proteins Elicits Potent Serum, Mucosal, and Cellular Immune Responses That Protect against Vaccinia Virus Env and Gag Challenges.

PubMed

Khattar, Sunil K; Manoharan, Vinoth; Bhattarai, Bikash; LaBranche, Celia C; Montefiori, David C; Samal, Siba K

2015-07-21

Newcastle disease virus (NDV) avirulent strain LaSota was used to coexpress gp160 Env and p55 Gag from a single vector to enhance both Env-specific and Gag-specific immune responses. The optimal transcription position for both Env and Gag genes in the NDV genome was determined by generating recombinant NDV (rNDV)-Env-Gag (gp160 located between the P and M genes and Gag between the HN and L genes), rNDV-Gag-Env (Gag located between the P and M genes and gp160 between the HN and L genes), rNDV-Env/Gag (gp160 followed by Gag located between the P and M genes), and rNDV-Gag/Env (Gag followed by gp160 located between the P and M genes). All the recombinant viruses replicated at levels similar to those seen with parental NDV in embryonated chicken eggs and in chicken fibroblast cells. Both gp160 and Gag proteins were expressed at high levels in cell culture, with gp160 found to be incorporated into the envelope of NDV. The Gag and Env proteins expressed by all the recombinants except rNDV-Env-Gag self-assembled into human immunodeficiency virus type 1 (HIV-1) virus-like particles (VLPs). Immunization of guinea pigs by the intranasal route with these rNDVs produced long-lasting Env- and Gag-specific humoral immune responses. The Env-specific humoral and mucosal immune responses and Gag-specific humoral immune responses were higher in rNDV-Gag/Env and rNDV-Env/Gag than in the other recombinants. rNDV-Gag/Env and rNDV-Env/Gag were also more efficient in inducing cellular as well as protective immune responses to challenge with vaccinia viruses expressing HIV-1 Env and Gag in mice. These results suggest that vaccination with a single rNDV coexpressing Env and Gag represents a promising strategy to enhance immunogenicity and protective efficacy against HIV. A safe and effective vaccine that can induce both systemic and mucosal immune responses is needed to control HIV-1. In this study, we showed that coexpression of Env and Gag proteins of HIV-1 performed using a single

Genomic Sequence and Virulence of Clonal Isolates of Vaccinia Virus Tiantan, the Chinese Smallpox Vaccine Strain

PubMed Central

Zhang, Qicheng; Tian, Meijuan; Feng, Yi; Zhao, Kai; Xu, Jing; Liu, Ying; Shao, Yiming

2013-01-01

Despite the worldwide eradication of smallpox in 1979, the potential bioterrorism threat from variola virus and the ongoing use of vaccinia virus (VACV) as a vector for vaccine development argue for continued research on VACV. In China, the VACV Tiantan strain (TT) was used in the smallpox eradication campaign. Its progeny strain is currently being used to develop a human immunodeficiency virus (HIV) vaccine. Here we sequenced the full genomes of five TT clones isolated by plaque purification from the TT (752-1) viral stock. Phylogenetic analysis with other commonly used VACV strains showed that TT (752-1) and its clones clustered and exhibited higher sequence diversity than that found in Dryvax clones. The ∼190 kbp genomes of TT appeared to encode 273 open reading frames (ORFs). ORFs located in the middle of the genome were more conserved than those located at the two termini, where many virulence and immunomodulation associated genes reside. Several patterns of nucleotide changes including point mutations, insertions and deletions were identified. The polymorphisms in seven virulence-associated proteins and six immunomodulation-related proteins were analyzed. We also investigated the neuro- and skin- virulence of TT clones in mice and rabbits, respectively. The TT clones exhibited significantly less virulence than the New York City Board of Health (NYCBH) strain, as evidenced by less extensive weight loss and morbidity in mice as well as produced smaller skin lesions and lower incidence of putrescence in rabbits. The complete genome sequences, ORF annotations, and phenotypic diversity yielded from this study aid our understanding of the Chinese historic TT strain and are useful for HIV vaccine projects employing TT as a vector. PMID:23593246

Genomic sequence and virulence of clonal isolates of vaccinia virus Tiantan, the Chinese smallpox vaccine strain.

PubMed

Zhang, Qicheng; Tian, Meijuan; Feng, Yi; Zhao, Kai; Xu, Jing; Liu, Ying; Shao, Yiming

2013-01-01

Despite the worldwide eradication of smallpox in 1979, the potential bioterrorism threat from variola virus and the ongoing use of vaccinia virus (VACV) as a vector for vaccine development argue for continued research on VACV. In China, the VACV Tiantan strain (TT) was used in the smallpox eradication campaign. Its progeny strain is currently being used to develop a human immunodeficiency virus (HIV) vaccine. Here we sequenced the full genomes of five TT clones isolated by plaque purification from the TT (752-1) viral stock. Phylogenetic analysis with other commonly used VACV strains showed that TT (752-1) and its clones clustered and exhibited higher sequence diversity than that found in Dryvax clones. The ∼190 kbp genomes of TT appeared to encode 273 open reading frames (ORFs). ORFs located in the middle of the genome were more conserved than those located at the two termini, where many virulence and immunomodulation associated genes reside. Several patterns of nucleotide changes including point mutations, insertions and deletions were identified. The polymorphisms in seven virulence-associated proteins and six immunomodulation-related proteins were analyzed. We also investigated the neuro- and skin- virulence of TT clones in mice and rabbits, respectively. The TT clones exhibited significantly less virulence than the New York City Board of Health (NYCBH) strain, as evidenced by less extensive weight loss and morbidity in mice as well as produced smaller skin lesions and lower incidence of putrescence in rabbits. The complete genome sequences, ORF annotations, and phenotypic diversity yielded from this study aid our understanding of the Chinese historic TT strain and are useful for HIV vaccine projects employing TT as a vector.

Effects of Postchallenge Administration of ST-246 on Dissemination of IHD-J-Luc Vaccinia Virus in Normal Mice and in Immune-Deficient Mice Reconstituted with T Cells

PubMed Central

Shotwell, Elisabeth; Scott, John; Cruz, Stephanie; King, Lisa R.; Manischewitz, Jody; Diaz, Claudia G.; Jordan, Robert A.; Grosenbach, Douglas W.; Golding, Hana

2013-01-01

Whole-body bioimaging was used to study dissemination of vaccinia virus (VACV) in normal and in immune deficient (nu−/nu−) mice protected from lethality by postchallenge administration of ST-246. Total fluxes were recorded in the liver, spleen, lungs, and nasal cavities of live mice after intranasal infection with a recombinant IHD-J-Luc VACV expressing luciferase. Areas under the flux curve were calculated for individual mice to assess viral loads. Treatment for 2 to 5 days of normal BALB/c mice with ST-246 at 100 mg/kg starting 24 h postchallenge conferred 100% protection and reduced viral loads in four organs compared to control mice. Mice also survived after 5 days of treatment with ST-246 at 30 mg/kg, and yet the viral loads and poxes were higher in these mice compared to 100-mg/kg treatment group. Nude mice were not protected by ST-246 alone or by 10 million adoptively transferred T cells. In contrast, nude mice that received T cells and 7-day treatment with ST-246 survived infection and exhibited reduced viral loads compared to nonreconstituted and ST-246-treated mice after ST-246 was stopped. Similar protection of nude mice was achieved using adoptively transferred 1.0 and 0.1 million, but not 0.01 million, purified T cells or CD4+ or CD8+ T cells in conjunction with ST-246 treatment. These data suggest that ST-246 protects immunocompetent mice from lethality and reduces viral dissemination in internal organs and poxvirus lesions. Furthermore, immune-deficient animals with partial T cell reconstitution can control virus replication after a course of ST-246 and survive lethal vaccinia virus challenge. PMID:23468500

Rapid Nipah virus entry into the central nervous system of hamsters via the olfactory route

PubMed Central

Munster, Vincent J.; Prescott, Joseph B.; Bushmaker, Trenton; Long, Dan; Rosenke, Rebecca; Thomas, Tina; Scott, Dana; Fischer, Elizabeth R.; Feldmann, Heinz; de Wit, Emmie

2012-01-01

Encephalitis is a hallmark of Nipah virus (NiV) infection in humans. The exact route of entry of NiV into the central nervous system (CNS) is unknown. Here, we performed a spatio-temporal analysis of NiV entry into the CNS of hamsters. NiV initially predominantly targeted the olfactory epithelium in the nasal turbinates. From there, NiV infected neurons were visible extending through the cribriform plate into the olfactory bulb, providing direct evidence of rapid CNS entry. Subsequently, NiV disseminated to the olfactory tubercle and throughout the ventral cortex. Transmission electron microscopy on brain tissue showed extravasation of plasma cells, neuronal degeneration and nucleocapsid inclusions in affected tissue and axons, providing further evidence for axonal transport of NiV. NiV entry into the CNS coincided with the occurrence of respiratory disease, suggesting that the initial entry of NiV into the CNS occurs simultaneously with, rather than as a result of, systemic virus replication. PMID:23071900

Improvement of In Vivo Expression of Genes Delivered by Self-Amplifying RNA Using Vaccinia Virus Immune Evasion Proteins.

PubMed

Beissert, Tim; Koste, Lars; Perkovic, Mario; Walzer, Kerstin C; Erbar, Stephanie; Selmi, Abderraouf; Diken, Mustafa; Kreiter, Sebastian; Türeci, Özlem; Sahin, Ugur

2017-12-01

Among nucleic acid-based delivery platforms, self-amplifying RNA (saRNA) vectors are of increasing interest for applications such as transient expression of recombinant proteins and vaccination. saRNA is safe and, due to its capability to amplify intracellularly, high protein levels can be produced from even minute amounts of transfected templates. However, it is an obstacle to full exploitation of this platform that saRNA induces a strong innate host immune response. In transfected cells, pattern recognition receptors sense double-stranded RNA intermediates and via activation of protein kinase R (PKR) and interferon signaling initiate host defense measures including a translational shutdown. To reduce pattern recognition receptor stimulation and unleash suppressed saRNA translation, this study co-delivered non-replicating mRNA encoding vaccinia virus immune evasion proteins E3, K3, and B18. It was shown that E3 is far superior to K3 or B18 as a highly potent blocker of PKR activation and of interferon (IFN)-β upregulation. B18, in contrast, is superior in controlling OAS1, a key IFN-inducible gene involved in viral RNA degradation. By combining all three vaccinia proteins, the study achieved significant suppression of PKR and IFN pathway activation in vitro and enhanced expression of saRNA-encoded genes of interest both in vitro and in vivo. This approach promises to overcome key hurdles of saRNA gene delivery. Its application may improve the bioavailability of the encoded protein, and reduce the effective dose and correspondingly the cost of goods of manufacture in the various fields where saRNA utilization is envisioned.

Improvement of In Vivo Expression of Genes Delivered by Self-Amplifying RNA Using Vaccinia Virus Immune Evasion Proteins

PubMed Central

Beissert, Tim; Koste, Lars; Perkovic, Mario; Walzer, Kerstin C.; Erbar, Stephanie; Selmi, Abderraouf; Diken, Mustafa; Kreiter, Sebastian; Türeci, Özlem; Sahin, Ugur

2017-01-01

Among nucleic acid–based delivery platforms, self-amplifying RNA (saRNA) vectors are of increasing interest for applications such as transient expression of recombinant proteins and vaccination. saRNA is safe and, due to its capability to amplify intracellularly, high protein levels can be produced from even minute amounts of transfected templates. However, it is an obstacle to full exploitation of this platform that saRNA induces a strong innate host immune response. In transfected cells, pattern recognition receptors sense double-stranded RNA intermediates and via activation of protein kinase R (PKR) and interferon signaling initiate host defense measures including a translational shutdown. To reduce pattern recognition receptor stimulation and unleash suppressed saRNA translation, this study co-delivered non-replicating mRNA encoding vaccinia virus immune evasion proteins E3, K3, and B18. It was shown that E3 is far superior to K3 or B18 as a highly potent blocker of PKR activation and of interferon (IFN)-β upregulation. B18, in contrast, is superior in controlling OAS1, a key IFN-inducible gene involved in viral RNA degradation. By combining all three vaccinia proteins, the study achieved significant suppression of PKR and IFN pathway activation in vitro and enhanced expression of saRNA-encoded genes of interest both in vitro and in vivo. This approach promises to overcome key hurdles of saRNA gene delivery. Its application may improve the bioavailability of the encoded protein, and reduce the effective dose and correspondingly the cost of goods of manufacture in the various fields where saRNA utilization is envisioned. PMID:28877647

The detection of Vaccinia virus confirms the high circulation of Orthopoxvirus in buffaloes living in geographical isolation, Marajó Island, Brazilian Amazon.

PubMed

Franco-Luiz, Ana Paula Moreira; Fagundes Pereira, Alexandre; de Oliveira, Cairo Henrique Sousa; Barbosa, José Diomedes; Oliveira, Danilo Bretas; Bonjardim, Cláudio Antônio; Ferreira, Paulo César Peregrino; de Souza Trindade, Giliane; Abrahão, Jônatas Santos; Kroon, Erna Geessien

2016-06-01

In Brazil, serologic evidence of Orthopoxvirus (OPV) circulation showed positivity around 20% in cattle, humans, monkeys and rodents. Although OPV seropositivity has been described in buffalo herds in southeastern Brazil, no Vaccinia virus (VACV) (member of genus OPV) outbreaks in buffalo herds have been described in this country. This study aimed to investigate the detection of anti-OPV antibodies and to study the OPV genome in Brazilian buffalo herds. Our results demonstrated a high OPV seropositivity in buffalo herds on Marajó Island and molecular data confirmed the circulation of VACV. The geographical isolation conditionmight be a sine qua non condition to explain our results. Copyright © 2016. Published by Elsevier Ltd.

Protective Efficacy of the Conserved NP, PB1, and M1 Proteins as Immunogens in DNA- and Vaccinia Virus-Based Universal Influenza A Virus Vaccines in Mice.

PubMed

Wang, Wenling; Li, Renqing; Deng, Yao; Lu, Ning; Chen, Hong; Meng, Xin; Wang, Wen; Wang, Xiuping; Yan, Kexia; Qi, Xiangrong; Zhang, Xiangmin; Xin, Wei; Lu, Zhenhua; Li, Xueren; Bian, Tao; Gao, Yingying; Tan, Wenjie; Ruan, Li

2015-06-01

The conventional hemagglutinin (HA)- and neuraminidase (NA)-based influenza vaccines need to be updated most years and are ineffective if the glycoprotein HA of the vaccine strains is a mismatch with that of the epidemic strain. Universal vaccines targeting conserved viral components might provide cross-protection and thus complement and improve conventional vaccines. In this study, we generated DNA plasmids and recombinant vaccinia viruses expressing the conserved proteins nucleoprotein (NP), polymerase basic 1 (PB1), and matrix 1 (M1) from influenza virus strain A/Beijing/30/95 (H3N2). BALB/c mice were immunized intramuscularly with a single vaccine based on NP, PB1, or M1 alone or a combination vaccine based on all three antigens and were then challenged with lethal doses of the heterologous influenza virus strain A/PR/8/34 (H1N1). Vaccines based on NP, PB1, and M1 provided complete or partial protection against challenge with 1.7 50% lethal dose (LD50) of PR8 in mice. Of the three antigens, NP-based vaccines induced protection against 5 LD50 and 10 LD50 and thus exhibited the greatest protective effect. Universal influenza vaccines based on the combination of NP, PB1, and M1 induced a strong immune response and thus might be an alternative approach to addressing future influenza virus pandemics. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Matrix-M™ adjuvant enhances immunogenicity of both protein- and modified vaccinia virus Ankara-based influenza vaccines in mice.

PubMed

Magnusson, Sofia E; Altenburg, Arwen F; Bengtsson, Karin Lövgren; Bosman, Fons; de Vries, Rory D; Rimmelzwaan, Guus F; Stertman, Linda

2018-04-01

Influenza viruses continuously circulate in the human population and escape recognition by virus neutralizing antibodies induced by prior infection or vaccination through accumulation of mutations in the surface proteins hemagglutinin (HA) and neuraminidase (NA). Various strategies to develop a vaccine that provides broad protection against different influenza A viruses are under investigation, including use of recombinant (r) viral vectors and adjuvants. The replication-deficient modified vaccinia virus Ankara (MVA) is a promising vaccine vector that efficiently induces B and T cell responses specific for the antigen of interest. It is assumed that live vaccine vectors do not require an adjuvant to be immunogenic as the vector already mediates recruitment and activation of immune cells. To address this topic, BALB/c mice were vaccinated with either protein- or rMVA-based HA influenza vaccines, formulated with or without the saponin-based Matrix-M™ adjuvant. Co-formulation with Matrix-M significantly increased HA vaccine immunogenicity, resulting in antigen-specific humoral and cellular immune responses comparable to those induced by unadjuvanted rMVA-HA. Of special interest, rMVA-HA immunogenicity was also enhanced by addition of Matrix-M, demonstrated by enhanced HA inhibition antibody titres and cellular immune responses. Matrix-M added to either protein- or rMVA-based HA vaccines mediated recruitment and activation of antigen-presenting cells and lymphocytes to the draining lymph node 24 and 48 h post-vaccination. Taken together, these results suggest that adjuvants can be used not only with protein-based vaccines but also in combination with rMVA to increase vaccine immunogenicity, which may be a step forward to generate new and more effective influenza vaccines.

Mapping vaccinia virus DNA replication origins at nucleotide level by deep sequencing.

PubMed

Senkevich, Tatiana G; Bruno, Daniel; Martens, Craig; Porcella, Stephen F; Wolf, Yuri I; Moss, Bernard

2015-09-01

Poxviruses reproduce in the host cytoplasm and encode most or all of the enzymes and factors needed for expression and synthesis of their double-stranded DNA genomes. Nevertheless, the mode of poxvirus DNA replication and the nature and location of the replication origins remain unknown. A current but unsubstantiated model posits only leading strand synthesis starting at a nick near one covalently closed end of the genome and continuing around the other end to generate a concatemer that is subsequently resolved into unit genomes. The existence of specific origins has been questioned because any plasmid can replicate in cells infected by vaccinia virus (VACV), the prototype poxvirus. We applied directional deep sequencing of short single-stranded DNA fragments enriched for RNA-primed nascent strands isolated from the cytoplasm of VACV-infected cells to pinpoint replication origins. The origins were identified as the switching points of the fragment directions, which correspond to the transition from continuous to discontinuous DNA synthesis. Origins containing a prominent initiation point mapped to a sequence within the hairpin loop at one end of the VACV genome and to the same sequence within the concatemeric junction of replication intermediates. These findings support a model for poxvirus genome replication that involves leading and lagging strand synthesis and is consistent with the requirements for primase and ligase activities as well as earlier electron microscopic and biochemical studies implicating a replication origin at the end of the VACV genome.

Multiple Phosphatidylinositol 3-Kinases Regulate Vaccinia Virus Morphogenesis

PubMed Central

McNulty, Shannon; Bornmann, William; Schriewer, Jill; Werner, Chas; Smith, Scott K.; Olson, Victoria A.; Damon, Inger K.; Buller, R. Mark; Heuser, John; Kalman, Daniel

2010-01-01

Poxvirus morphogenesis is a complex process that involves the successive wrapping of the virus in host cell membranes. We screened by plaque assay a focused library of kinase inhibitors for those that caused a reduction in viral growth and identified several compounds that selectively inhibit phosphatidylinositol 3-kinase (PI3K). Previous studies demonstrated that PI3Ks mediate poxviral entry. Using growth curves and electron microscopy in conjunction with inhibitors, we show that that PI3Ks additionally regulate morphogenesis at two distinct steps: immature to mature virion (IMV) transition, and IMV envelopment to form intracellular enveloped virions (IEV). Cells derived from animals lacking the p85 regulatory subunit of Type I PI3Ks (p85α−/−β−/−) presented phenotypes similar to those observed with PI3K inhibitors. In addition, VV appear to redundantly use PI3Ks, as PI3K inhibitors further reduce plaque size and number in p85α−/−β−/− cells. Together, these data provide evidence for a novel regulatory mechanism for virion morphogenesis involving phosphatidylinositol dynamics and may represent a new therapeutic target to contain poxviruses. PMID:20526370

Identification of Ellagic Acid from Plant Rhodiola rosea L. as an Anti-Ebola Virus Entry Inhibitor.

PubMed

Cui, Qinghua; Du, Ruikun; Anantpadma, Manu; Schafer, Adam; Hou, Lin; Tian, Jingzhen; Davey, Robert A; Cheng, Han; Rong, Lijun

2018-03-27

The recent 2014-2016 West African Ebola virus epidemic underscores the need for the development of novel anti-Ebola therapeutics, due to the high mortality rates of Ebola virus infections and the lack of FDA-approved vaccine or therapy that is available for the prevention and treatment. Traditional Chinese medicines (TCMs) represent a huge reservoir of bioactive chemicals and many TCMs have been shown to have antiviral activities. 373 extracts from 128 TCMs were evaluated using a high throughput assay to screen for inhibitors of Ebola virus cell entry. Extract of Rhodiola rosea displayed specific and potent inhibition against cell entry of both Ebola virus and Marburg virus. In addition, twenty commercial compounds that were isolated from Rhodiola rosea were evaluated using the pseudotyped Ebola virus entry assay, and it was found that ellagic acid and gallic acid, which are two structurally related compounds, are the most effective ones. The activity of the extract and the two pure compounds were validated using infectious Ebola virus. The time-of-addition experiments suggest that, mechanistically, the Rhodiola rosea extract and the effective compounds act at an early step in the infection cycle following initial cell attachment, but prior to viral/cell membrane fusion. Our findings provide evidence that Rhodiola rosea has potent anti-filovirus properties that may be developed as a novel anti-Ebola treatment.

Identification of Ellagic Acid from Plant Rhodiola rosea L. as an Anti-Ebola Virus Entry Inhibitor

PubMed Central

Cui, Qinghua; Du, Ruikun; Anantpadma, Manu; Schafer, Adam; Hou, Lin; Tian, Jingzhen; Cheng, Han; Rong, Lijun

2018-01-01

The recent 2014–2016 West African Ebola virus epidemic underscores the need for the development of novel anti-Ebola therapeutics, due to the high mortality rates of Ebola virus infections and the lack of FDA-approved vaccine or therapy that is available for the prevention and treatment. Traditional Chinese medicines (TCMs) represent a huge reservoir of bioactive chemicals and many TCMs have been shown to have antiviral activities. 373 extracts from 128 TCMs were evaluated using a high throughput assay to screen for inhibitors of Ebola virus cell entry. Extract of Rhodiola rosea displayed specific and potent inhibition against cell entry of both Ebola virus and Marburg virus. In addition, twenty commercial compounds that were isolated from Rhodiola rosea were evaluated using the pseudotyped Ebola virus entry assay, and it was found that ellagic acid and gallic acid, which are two structurally related compounds, are the most effective ones. The activity of the extract and the two pure compounds were validated using infectious Ebola virus. The time-of-addition experiments suggest that, mechanistically, the Rhodiola rosea extract and the effective compounds act at an early step in the infection cycle following initial cell attachment, but prior to viral/cell membrane fusion. Our findings provide evidence that Rhodiola rosea has potent anti-filovirus properties that may be developed as a novel anti-Ebola treatment. PMID:29584652

Vaccinia virus decreases major histocompatibility complex (MHC) class II antigen presentation, T-cell priming, and peptide association with MHC class II

PubMed Central

Rehm, Kristina E; Connor, Ramsey F; Jones, Gwendolyn J B; Yimbu, Kenneth; Mannie, Mark D; Roper, Rachel L

2009-01-01

Vaccinia virus (VACV) is the current live virus vaccine used to protect humans against smallpox and monkeypox, but its use is contraindicated in several populations because of its virulence. It is therefore important to elucidate the immune evasion mechanisms of VACV. We found that VACV infection of antigen-presenting cells (APCs) significantly decreased major histocompatibility complex (MHC) II antigen presentation and decreased synthesis of 13 chemokines and cytokines, suggesting a potent viral mechanism for immune evasion. In these model systems, responding T cells were not directly affected by virus, indicating that VACV directly affects the APC. VACV significantly decreased nitric oxide production by peritoneal exudate cells and the RAW macrophage cell line in response to lipopolysaccharide (LPS) and interferon (IFN)-γ, decreased class II MHC expression on APCs, and induced apoptosis in macrophages and dendritic cells. However, VACV decreased antigen presentation by 1153 B cells without apparent apoptosis induction, indicating that VACV differentially affects B lymphocytes and other APCs. We show that the key mechanism of VACV inhibition of antigen presentation may be its reduction of antigenic peptide loaded into the cleft of MHC class II molecules. These data indicate that VACV evades the host immune response by impairing critical functions of the APC. PMID:20067538

Molecular requirement for sterols in herpes simplex virus entry and infectivity

USDA-ARS?s Scientific Manuscript database

Herpes simplex virus 1 (HSV-1) required cholesterol for virion-induced membrane fusion. HSV successfully entered DHCR24-/-cells, which lack a desmosterol-to-cholesterol conversion enzyme, indicating entry can occur independently of cholesterol. Depletion of desmosterol from these cells resulted in d...

Development and Evaluation of Adeno-HTLV-III Hybrid Virus and Non-Cytopathic HTLV-III Mutant for Vaccine Use.

DTIC Science & Technology

1987-10-28

34" HIV will be tested. The recombinant Adeno-HIV virus is being developed as part of this proposal. The vaccines will be tested in two species of monkeys...vaccinia-HIV viruses was investigated (Table 4). All the vaccinated monkeys developed antibodies to HIV envelope antigen. However, no neutralizing antibody...Table 5). Epstein Barr virus transformed autologous B cells infected with recon- binant vaccinia-HIV virus may be used as targets. 30 chimpanzees from

Vectorization in an oncolytic vaccinia virus of an antibody, a Fab and a scFv against programmed cell death -1 (PD-1) allows their intratumoral delivery and an improved tumor-growth inhibition.

PubMed

Kleinpeter, Patricia; Fend, Laetitia; Thioudellet, Christine; Geist, Michel; Sfrontato, Nathalie; Koerper, Véronique; Fahrner, Catherine; Schmitt, Doris; Gantzer, Murielle; Remy-Ziller, Christelle; Brandely, Renée; Villeval, Dominique; Rittner, Karola; Silvestre, Nathalie; Erbs, Philippe; Zitvogel, Laurence; Quéméneur, Eric; Préville, Xavier; Marchand, Jean-Baptiste

2016-01-01

We report here the successful vectorization of a hamster monoclonal IgG (namely J43) recognizing the murine Programmed cell death-1 (mPD-1) in Western Reserve (WR) oncolytic vaccinia virus. Three forms of mPD-1 binders have been inserted into the virus: whole antibody (mAb), Fragment antigen-binding (Fab) or single-chain variable fragment (scFv). MAb, Fab and scFv were produced and assembled with the expected patterns in supernatants of cells infected by the recombinant viruses. The three purified mPD-1 binders were able to block the binding of mPD-1 ligand to mPD-1 in vitro . Moreover, mAb was detected in tumor and in serum of C57BL/6 mice when the recombinant WR-mAb was injected intratumorally (IT) in B16F10 and MCA 205 tumors. The concentration of circulating mAb detected after IT injection was up to 1,900-fold higher than the level obtained after a subcutaneous (SC) injection (i.e., without tumor) confirming the virus tropism for tumoral cells and/or microenvironment. Moreover, the overall tumoral accumulation of the mAb was higher and lasted longer after IT injection of WR-mAb1, than after IT administration of 10 µg of J43. The IT injection of viruses induced a massive infiltration of immune cells including activated lymphocytes (CD8 + and CD4 + ). Interestingly, in the MCA 205 tumor model, WR-mAb1 and WR-scFv induced a therapeutic control of tumor growth similar to unarmed WR combined to systemically administered J43 and superior to that obtained with an unarmed WR. These results pave the way for next generation of oncolytic vaccinia armed with immunomodulatory therapeutic proteins such as mAbs.

Vectorization in an oncolytic vaccinia virus of an antibody, a Fab and a scFv against programmed cell death -1 (PD-1) allows their intratumoral delivery and an improved tumor-growth inhibition

PubMed Central

Kleinpeter, Patricia; Fend, Laetitia; Thioudellet, Christine; Geist, Michel; Sfrontato, Nathalie; Koerper, Véronique; Fahrner, Catherine; Schmitt, Doris; Gantzer, Murielle; Remy-Ziller, Christelle; Brandely, Renée; Villeval, Dominique; Rittner, Karola; Silvestre, Nathalie; Erbs, Philippe; Zitvogel, Laurence; Quéméneur, Eric; Préville, Xavier; Marchand, Jean-Baptiste

2016-01-01

ABSTRACT We report here the successful vectorization of a hamster monoclonal IgG (namely J43) recognizing the murine Programmed cell death-1 (mPD-1) in Western Reserve (WR) oncolytic vaccinia virus. Three forms of mPD-1 binders have been inserted into the virus: whole antibody (mAb), Fragment antigen-binding (Fab) or single-chain variable fragment (scFv). MAb, Fab and scFv were produced and assembled with the expected patterns in supernatants of cells infected by the recombinant viruses. The three purified mPD-1 binders were able to block the binding of mPD-1 ligand to mPD-1 in vitro. Moreover, mAb was detected in tumor and in serum of C57BL/6 mice when the recombinant WR-mAb was injected intratumorally (IT) in B16F10 and MCA 205 tumors. The concentration of circulating mAb detected after IT injection was up to 1,900-fold higher than the level obtained after a subcutaneous (SC) injection (i.e., without tumor) confirming the virus tropism for tumoral cells and/or microenvironment. Moreover, the overall tumoral accumulation of the mAb was higher and lasted longer after IT injection of WR-mAb1, than after IT administration of 10 µg of J43. The IT injection of viruses induced a massive infiltration of immune cells including activated lymphocytes (CD8+ and CD4+). Interestingly, in the MCA 205 tumor model, WR-mAb1 and WR-scFv induced a therapeutic control of tumor growth similar to unarmed WR combined to systemically administered J43 and superior to that obtained with an unarmed WR. These results pave the way for next generation of oncolytic vaccinia armed with immunomodulatory therapeutic proteins such as mAbs. PMID:27853644

Entry mechanisms of herpes simplex virus 1 into murine epidermis: involvement of nectin-1 and herpesvirus entry mediator as cellular receptors.

PubMed

Petermann, Philipp; Thier, Katharina; Rahn, Elena; Rixon, Frazer J; Bloch, Wilhelm; Özcelik, Semra; Krummenacher, Claude; Barron, Martin J; Dixon, Michael J; Scheu, Stefanie; Pfeffer, Klaus; Knebel-Mörsdorf, Dagmar

2015-01-01

Skin keratinocytes represent a primary entry site for herpes simplex virus 1 (HSV-1) in vivo. The cellular proteins nectin-1 and herpesvirus entry mediator (HVEM) act as efficient receptors for both serotypes of HSV and are sufficient for disease development mediated by HSV-2 in mice. How HSV-1 enters skin and whether both nectin-1 and HVEM are involved are not known. We addressed the impact of nectin-1 during entry of HSV-1 into murine epidermis and investigated the putative contribution of HVEM. Using ex vivo infection of murine epidermis, we showed that HSV-1 entered the basal keratinocytes of the epidermis very efficiently. In nectin-1-deficient epidermis, entry was strongly reduced. Almost no entry was observed, however, in nectin-1-deficient keratinocytes grown in culture. This observation correlated with the presence of HVEM on the keratinocyte surface in epidermis and with the lack of HVEM expression in nectin-1-deficient primary keratinocytes. Our results suggest that nectin-1 is the primary receptor in epidermis, while HVEM has a more limited role. For primary murine keratinocytes, on which nectin-1 acts as a single receptor, electron microscopy suggested that HSV-1 can enter both by direct fusion with the plasma membrane and via endocytic vesicles. Thus, we concluded that nectin-1 directs internalization into keratinocytes via alternative pathways. In summary, HSV-1 entry into epidermis was shown to strongly depend on the presence of nectin-1, but the restricted presence of HVEM can potentially replace nectin-1 as a receptor, illustrating the flexibility employed by HSV-1 to efficiently invade tissue in vivo. Herpes simplex virus (HSV) can cause a range of diseases in humans, from uncomplicated mucocutaneous lesions to life-threatening infections. The skin is one target tissue of HSV, and the question of how the virus overcomes the protective skin barrier and penetrates into the tissue to reach its receptors is still open. Previous studies analyzing

Role of Metalloproteases in Vaccinia Virus Epitope Processing for Transporter Associated with Antigen Processing (TAP)-independent Human Leukocyte Antigen (HLA)-B7 Class I Antigen Presentation*

PubMed Central

Lorente, Elena; García, Ruth; Mir, Carmen; Barriga, Alejandro; Lemonnier, François A.; Ramos, Manuel; López, Daniel

2012-01-01

The transporter associated with antigen processing (TAP) translocates the viral proteolytic peptides generated by the proteasome and other proteases in the cytosol to the endoplasmic reticulum lumen. There, they complex with nascent human leukocyte antigen (HLA) class I molecules, which are subsequently recognized by the CD8+ lymphocyte cellular response. However, individuals with nonfunctional TAP complexes or tumor or infected cells with blocked TAP molecules are able to present HLA class I ligands generated by TAP-independent processing pathways. Herein, using a TAP-independent polyclonal vaccinia virus-polyspecific CD8+ T cell line, two conserved vaccinia-derived TAP-independent HLA-B*0702 epitopes were identified. The presentation of these epitopes in normal cells occurs via complex antigen-processing pathways involving the proteasome and/or different subsets of metalloproteinases (amino-, carboxy-, and endoproteases), which were blocked in infected cells with specific chemical inhibitors. These data support the hypothesis that the abundant cellular proteolytic systems contribute to the supply of peptides recognized by the antiviral cellular immune response, thereby facilitating immunosurveillance. These data may explain why TAP-deficient individuals live normal life spans without any increased susceptibility to viral infections. PMID:22298786

Variola virus immune evasion design: expression of a highly efficient inhibitor of human complement.

PubMed

Rosengard, Ariella M; Liu, Yu; Nie, Zhiping; Jimenez, Robert

2002-06-25

Variola virus, the most virulent member of the genus Orthopoxvirus, specifically infects humans and has no other animal reservoir. Variola causes the contagious disease smallpox, which has a 30-40% mortality rate. Conversely, the prototype orthopoxvirus, vaccinia, causes no disease in immunocompetent humans and was used in the global eradication of smallpox, which ended in 1977. However, the threat of smallpox persists because clandestine stockpiles of variola still exist. Although variola and vaccinia share remarkable DNA homology, the strict human tropism of variola suggests that its proteins are better suited than those of vaccinia to overcome the human immune response. Here, we demonstrate the functional advantage of a variola complement regulatory protein over that of its vaccinia homologue. Because authentic variola proteins are not available for study, we molecularly engineered and characterized the smallpox inhibitor of complement enzymes (SPICE), a homologue of a vaccinia virulence factor, vaccinia virus complement control protein (VCP). SPICE is nearly 100-fold more potent than VCP at inactivating human C3b and 6-fold more potent at inactivating C4b. SPICE is also more human complement-specific than is VCP. By inactivating complement components, SPICE serves to inhibit the formation of the C3/C5 convertases necessary for complement-mediated viral clearance. SPICE provides the first evidence that variola proteins are particularly adept at overcoming human immunity, and the decreased function of VCP suggests one reason why the vaccinia virus vaccine was associated with relatively low mortality. Disabling SPICE may be therapeutically useful if smallpox reemerges.

Variola virus immune evasion design: Expression of a highly efficient inhibitor of human complement

PubMed Central

Rosengard, Ariella M.; Liu, Yu; Nie, Zhiping; Jimenez, Robert

2002-01-01

Variola virus, the most virulent member of the genus Orthopoxvirus, specifically infects humans and has no other animal reservoir. Variola causes the contagious disease smallpox, which has a 30–40% mortality rate. Conversely, the prototype orthopoxvirus, vaccinia, causes no disease in immunocompetent humans and was used in the global eradication of smallpox, which ended in 1977. However, the threat of smallpox persists because clandestine stockpiles of variola still exist. Although variola and vaccinia share remarkable DNA homology, the strict human tropism of variola suggests that its proteins are better suited than those of vaccinia to overcome the human immune response. Here, we demonstrate the functional advantage of a variola complement regulatory protein over that of its vaccinia homologue. Because authentic variola proteins are not available for study, we molecularly engineered and characterized the smallpox inhibitor of complement enzymes (SPICE), a homologue of a vaccinia virulence factor, vaccinia virus complement control protein (VCP). SPICE is nearly 100-fold more potent than VCP at inactivating human C3b and 6-fold more potent at inactivating C4b. SPICE is also more human complement-specific than is VCP. By inactivating complement components, SPICE serves to inhibit the formation of the C3/C5 convertases necessary for complement-mediated viral clearance. SPICE provides the first evidence that variola proteins are particularly adept at overcoming human immunity, and the decreased function of VCP suggests one reason why the vaccinia virus vaccine was associated with relatively low mortality. Disabling SPICE may be therapeutically useful if smallpox reemerges. PMID:12034872

Entry of porcine reproductive and respiratory syndrome virus into porcine alveolar macrophages via receptor-mediated endocytosis.

PubMed

Nauwynck, H J; Duan, X; Favoreel, H W; Van Oostveldt, P; Pensaert, M B

1999-02-01

Porcine alveolar macrophages (AMphi) are the dominant cell type that supports the replication of porcine reproductive and respiratory syndrome virus (PRRSV) in vivo and in vitro. In order to determine the characteristics of the virus-receptor interaction, the attachment of PRRSV to cells was examined by using biotinylated virus in a series of flow cytometric assays. PRRSV bound specifically to AMphi in a dose-dependent manner. Binding of PRRSV to AMphi increased gradually and reached a maximum within 60 min at 4 degrees C. By confocal microscopy, it was shown that different degrees of PRRSV binding exist and that entry is by endocytosis. Virus uptake in vesicles is a clathrin-dependent process, as it was blocked by the addition of cytochalasin D and co-localization of PRRSV and clathrin was found. Furthermore, by the use of two weak bases, NH4Cl and chloroquine, it was demonstrated that PRRSV uses a low pH-dependent entry pathway. In the presence of these reagents, input virions accumulated in large vacuoles, indicating that uncoating was prevented. These results indicate that PRRSV entry into AMphi involves attachment to a specific virus receptor(s) followed by a process of endocytosis, by which virions are taken into the cell within vesicles by a clathrin-dependent pathway. A subsequent drop in pH is required for proper virus replication.

Efficient and stable production of Modified Vaccinia Ankara virus in two-stage semi-continuous and in continuous stirred tank cultivation systems.

PubMed

Tapia, Felipe; Jordan, Ingo; Genzel, Yvonne; Reichl, Udo

2017-01-01

One important aim in cell culture-based viral vaccine and vector production is the implementation of continuous processes. Such a development has the potential to reduce costs of vaccine manufacturing as volumetric productivity is increased and the manufacturing footprint is reduced. In this work, continuous production of Modified Vaccinia Ankara (MVA) virus was investigated. First, a semi-continuous two-stage cultivation system consisting of two shaker flasks in series was established as a small-scale approach. Cultures of the avian AGE1.CR.pIX cell line were expanded in the first shaker, and MVA virus was propagated and harvested in the second shaker over a period of 8-15 days. A total of nine small-scale cultivations were performed to investigate the impact of process parameters on virus yields. Harvest volumes of 0.7-1 L with maximum TCID50 titers of up to 1.0×109 virions/mL were obtained. Genetic analysis of control experiments using a recombinant MVA virus containing green-fluorescent-protein suggested that the virus was stable over at least 16 d of cultivation. In addition, a decrease or fluctuation of infectious units that may indicate an excessive accumulation of defective interfering particles was not observed. The process was automated in a two-stage continuous system comprising two connected 1 L stirred tank bioreactors. Stable MVA virus titers, and a total production volume of 7.1 L with an average TCID50 titer of 9×107 virions/mL was achieved. Because titers were at the lower range of the shake flask cultivations potential for further process optimization at large scale will be discussed. Overall, MVA virus was efficiently produced in continuous and semi-continuous cultivations making two-stage stirred tank bioreactor systems a promising platform for industrial production of MVA-derived recombinant vaccines and viral vectors.

Effective Induction of Simian Immunodeficiency Virus-Specific Cytotoxic T Lymphocytes in Macaques by Using a Multiepitope Gene and DNA Prime-Modified Vaccinia Virus Ankara Boost Vaccination Regimen

PubMed Central

Hanke, Tomas; Samuel, Rachel V.; Blanchard, Tom J.; Neumann, Veronica C.; Allen, Todd M.; Boyson, Jon E.; Sharpe, Sally A.; Cook, Nicola; Smith, Geoffrey L.; Watkins, David I.; Cranage, Martin P.; McMichael, Andrew J.

1999-01-01

DNA and modified vaccinia virus Ankara (MVA) are vaccine vehicles suitable and safe for use in humans. Here, by using a multicytotoxic T-lymphocyte (CTL) epitope gene and a DNA prime-MVA boost vaccination regimen, high levels of CTLs specific for a single simian immunodeficiency virus (SIV) gag-derived epitope were elicited in rhesus macaques. These vaccine-induced CTLs were capable of killing SIV-infected cells in vitro. Fluorescence-activated cell sorter analysis using soluble tetrameric major histocompatibility complex-peptide complexes showed that the vaccinated animals had 1 to 5% circulating CD8+ lymphocytes specific for the vaccine epitope, frequencies comparable to those in SIV-infected monkeys. Upon intrarectal challenge with pathogenic SIVmac251, no evidence for protection was observed in at least two of the three vaccinated animals. This study does not attempt to define correlates of protective immunity nor design a protective vaccine against immunodeficiency viruses, but it demonstrates clearly that the DNA prime-MVA boost regimen is an effective protocol for induction of CTLs in macaques. It also shows that powerful tools for studying the role of CTLs in the control of SIV and human immunodeficiency virus infections are now available: epitope-based vaccines, a protocol for an effective induction of CTLs in primates, and a simple and sensitive method for quantitation of epitope-specific T cells. The advantages of the DNA prime-MVA boost regimen as well as the correlations of tetramer staining of peripheral blood lymphocytes with CTL killing in vitro and postchallenge control of viremia are discussed. PMID:10438842

Humoral Immunity to Primary Smallpox Vaccination: Impact of Childhood versus Adult Immunization on Vaccinia Vector Vaccine Development in Military Populations.

PubMed

Slike, Bonnie M; Creegan, Matthew; Marovich, Mary; Ngauy, Viseth

2017-01-01

Modified Vaccinia virus has been shown to be a safe and immunogenic vector platform for delivery of HIV vaccines. Use of this vector is of particular importance to the military, with the implementation of a large scale smallpox vaccination campaign in 2002 in active duty and key civilian personnel in response to potential bioterrorist activities. Humoral immunity to smallpox vaccination was previously shown to be long lasting (up to 75 years) and protective. However, using vaccinia-vectored vaccine delivery for other diseases on a background of anti-vector antibodies (i.e. pre-existing immunity) may limit their use as a vaccine platform, especially in the military. In this pilot study, we examined the durability of vaccinia antibody responses in adult primary vaccinees in a healthy military population using a standard ELISA assay and a novel dendritic cell neutralization assay. We found binding and neutralizing antibody (NAb) responses to vaccinia waned after 5-10 years in a group of 475 active duty military, born after 1972, who were vaccinated as adults with Dryvax®. These responses decreased from a geometric mean titer (GMT) of 250 to baseline (<20) after 10-20 years post vaccination. This contrasted with a comparator group of adults, ages 35-49, who were vaccinated with Dryvax® as children. In the childhood vaccinees, titers persisted for >30 years with a GMT of 210 (range 112-3234). This data suggests limited durability of antibody responses in adult vaccinees compared to those vaccinated in childhood and further that adult vaccinia recipients may benefit similarly from receipt of a vaccinia based vaccine as those who are vaccinia naïve. Our findings may have implications for the smallpox vaccination schedule and support the ongoing development of this promising viral vector in a military vaccination program.

Humoral Immunity to Primary Smallpox Vaccination: Impact of Childhood versus Adult Immunization on Vaccinia Vector Vaccine Development in Military Populations

PubMed Central

Slike, Bonnie M.; Creegan, Matthew

2017-01-01

Modified Vaccinia virus has been shown to be a safe and immunogenic vector platform for delivery of HIV vaccines. Use of this vector is of particular importance to the military, with the implementation of a large scale smallpox vaccination campaign in 2002 in active duty and key civilian personnel in response to potential bioterrorist activities. Humoral immunity to smallpox vaccination was previously shown to be long lasting (up to 75 years) and protective. However, using vaccinia-vectored vaccine delivery for other diseases on a background of anti-vector antibodies (i.e. pre-existing immunity) may limit their use as a vaccine platform, especially in the military. In this pilot study, we examined the durability of vaccinia antibody responses in adult primary vaccinees in a healthy military population using a standard ELISA assay and a novel dendritic cell neutralization assay. We found binding and neutralizing antibody (NAb) responses to vaccinia waned after 5–10 years in a group of 475 active duty military, born after 1972, who were vaccinated as adults with Dryvax®. These responses decreased from a geometric mean titer (GMT) of 250 to baseline (<20) after 10–20 years post vaccination. This contrasted with a comparator group of adults, ages 35–49, who were vaccinated with Dryvax® as children. In the childhood vaccinees, titers persisted for >30 years with a GMT of 210 (range 112–3234). This data suggests limited durability of antibody responses in adult vaccinees compared to those vaccinated in childhood and further that adult vaccinia recipients may benefit similarly from receipt of a vaccinia based vaccine as those who are vaccinia naïve. Our findings may have implications for the smallpox vaccination schedule and support the ongoing development of this promising viral vector in a military vaccination program. PMID:28046039

Poliovirus Cell Entry: Common Structural Themes in Viral Cell Entry Pathways

PubMed Central

Hogle, James M.

2006-01-01

Structural studies of polio- and closely related viruses have provided a series of snapshots along their cell entry pathways. Based on the structures and related kinetic, biochemical, and genetic studies, we have proposed a model for the cell entry pathway for polio- and closely related viruses. In this model a maturation cleavage of a capsid protein precursor locks the virus in a metastable state, and the receptor acts like a transition-state catalyst to overcome an energy barrier and release the mature virion from the metastable state. This initiates a series of conformational changes that allow the virus to attach to membranes, form a pore, and finally release its RNA genome into the cytoplasm. This model has striking parallels with emerging models for the maturation and cell entry of more complex enveloped viruses such as influenza virus and HIV. PMID:12142481

Transforming growth factor alpha, Shope fibroma growth factor, and vaccinia growth factor can replace myxoma growth factor in the induction of myxomatosis in rabbits.

PubMed

Opgenorth, A; Nation, N; Graham, K; McFadden, G

1993-02-01

The epidermal growth factor (EGF) homologues encoded by vaccinia virus, myxoma virus, and malignant rabbit fibroma virus have been shown to contribute to the pathogenicity of virus infection upon inoculation of susceptible hosts. However, since the primary structures of these growth factors and the disease profiles induced by different poxvirus genera vary substantially, the degree to which the various EGF homologues perform similar roles in viral pathogenesis remains unclear. In order to determine whether different EGF-like growth factors can perform qualitatively similar functions in the induction of myxomatosis in rabbits, we created recombinant myxoma virus variants in which the native growth factor, myxoma growth factor (MGF), was disrupted and replaced with either vaccinia virus growth factor, Shope fibroma growth factor, or rat transforming growth factor alpha. Unlike the control virus containing an inactivated MGF gene, which caused marked attenuation of the disease syndrome and substantially less proliferation of the epithelial cell layers in the conjunctiva and respiratory tract, the recombinant myxoma virus strains expressing heterologous growth factors produced infections which were both clinically and histopathologically indistinguishable from wild-type myxomatosis. We conclude that these poxviral and cellular EGF-like growth factors, which are diverse with respect to primary structure and origin, have similar biological functions in the context of myxoma virus pathogenesis and are mitogenic for the same target cells.

Mutational analysis of vaccinia virus E3 protein: the biological functions do not correlate with its biochemical capacity to bind double-stranded RNA.

PubMed

Dueck, Kevin J; Hu, YuanShen Sandy; Chen, Peter; Deschambault, Yvon; Lee, Jocelyn; Varga, Jessie; Cao, Jingxin

2015-05-01

Vaccinia E3 protein has the biochemical capacity of binding to double-stranded RNA (dsRNA). The best characterized biological functions of the E3 protein include its host range function, suppression of cytokine expression, and inhibition of interferon (IFN)-induced antiviral activity. Currently, the role of the dsRNA binding capacity in the biological functions of the E3 protein is not clear. To further understand the mechanism of the E3 protein biological functions, we performed alanine scanning of the entire dsRNA binding domain of the E3 protein to examine the link between its biochemical capacity of dsRNA binding and biological functions. Of the 115 mutants examined, 20 were defective in dsRNA binding. Although the majority of the mutants defective in dsRNA binding also showed defective replication in HeLa cells, nine mutants (I105A, Y125A, E138A, F148A, F159A, K171A, L182A, L183A, and I187/188A) retained the host range function to various degrees. Further examination of a set of representative E3L mutants showed that residues essential for dsRNA binding are not essential for the biological functions of E3 protein, such as inhibition of protein kinase R (PKR) activation, suppression of cytokine expression, and apoptosis. Thus, data described in this communication strongly indicate the E3 protein performs its biological functions via a novel mechanism which does not correlate with its dsRNA binding activity. dsRNAs produced during virus replication are important pathogen-associated molecular patterns (PAMPs) for inducing antiviral immune responses. One of the strategies used by many viruses to counteract such antiviral immune responses is achieved by producing dsRNA binding proteins, such as poxvirus E3 family proteins, influenza virus NS1, and Ebola virus V35 proteins. The most widely accepted model for the biological functions of this class of viral dsRNA binding proteins is that they bind to and sequester viral dsRNA PAMPs; thus, they suppress the related

Ebola virus. Two-pore channels control Ebola virus host cell entry and are drug targets for disease treatment.

PubMed

Sakurai, Yasuteru; Kolokoltsov, Andrey A; Chen, Cheng-Chang; Tidwell, Michael W; Bauta, William E; Klugbauer, Norbert; Grimm, Christian; Wahl-Schott, Christian; Biel, Martin; Davey, Robert A

2015-02-27

Ebola virus causes sporadic outbreaks of lethal hemorrhagic fever in humans, but there is no currently approved therapy. Cells take up Ebola virus by macropinocytosis, followed by trafficking through endosomal vesicles. However, few factors controlling endosomal virus movement are known. Here we find that Ebola virus entry into host cells requires the endosomal calcium channels called two-pore channels (TPCs). Disrupting TPC function by gene knockout, small interfering RNAs, or small-molecule inhibitors halted virus trafficking and prevented infection. Tetrandrine, the most potent small molecule that we tested, inhibited infection of human macrophages, the primary target of Ebola virus in vivo, and also showed therapeutic efficacy in mice. Therefore, TPC proteins play a key role in Ebola virus infection and may be effective targets for antiviral therapy. Copyright © 2015, American Association for the Advancement of Science.

Daily ingestion of the probiotic Lactobacillus paracasei ST11 decreases Vaccinia virus dissemination and lethality in a mouse model.

PubMed

Dos Santos Pereira Andrade, A C; Lima, M Teixeira; Oliveira, G Pereira; Calixto, R Silva; de Sales E Souza, É Lorenna; da Glória de Souza, D; de Almeida Leite, C M; Ferreira, J M Siqueira; Kroon, E G; de Oliveira, D Bretas; Dos Santos Martins, F; Abrahão, J S

2017-02-07

Vaccinia virus (VACV) is an important pathogen. Although studies have shown relationships between probiotics and viruses, the effect of probiotics on VACV infection is unknown. Therefore, this work aims to investigate the probiotics effects on VACV infection. Mice were divided into four groups, two non-infected groups, one receiving the probiotic, the other one not receiving it, and two groups infected intranasally with VACV Western Reserve (VACV-WR) receiving or not receiving the probiotic. Viral titres in organs and cytokine production in the lungs were analysed. Lung samples were also subjected to histological analysis. The intake of probiotic results in reduction in viral spread with a significant decrease of VACV titer on lung, liver and brain of treated group. In addition,treatment with the probiotic results in attenuated mice lung inflammation showing fewer lesions on histological findings and decreased lethality in mice infected with VACV. The ingestion of Lactobacillus paracasei ST11 (LPST11) after VACV infection resulted in 2/9 animal lethality compared with 4/9 in the VACV group. This is the first study on probiotics and VACV interactions, providing not only information about this interaction, but also proposing a model for future studies involving probiotics and other poxvirus.

Nipah virion entry kinetics, composition, and conformational changes determined by enzymatic virus-like particles and new flow virometry tools.

PubMed

Landowski, Matthew; Dabundo, Jeffrey; Liu, Qian; Nicola, Anthony V; Aguilar, Hector C

2014-12-01

Virus-cell membrane fusion is essential for enveloped virus infections. However, mechanistic viral membrane fusion studies have predominantly focused on cell-cell fusion models, largely due to the low availability of technologies capable of characterizing actual virus-cell membrane fusion. Although cell-cell fusion assays are valuable, they do not fully recapitulate all the variables of virus-cell membrane fusion. Drastic differences between viral and cellular membrane lipid and protein compositions and curvatures exist. For biosafety level 4 (BSL4) pathogens such as the deadly Nipah virus (NiV), virus-cell fusion mechanistic studies are notably cumbersome. To circumvent these limitations, we used enzymatic Nipah virus-like-particles (NiVLPs) and developed new flow virometric tools. NiV's attachment (G) and fusion (F) envelope glycoproteins mediate viral binding to the ephrinB2/ephrinB3 cell receptors and virus-cell membrane fusion, respectively. The NiV matrix protein (M) can autonomously induce NiV assembly and budding. Using a β-lactamase (βLa) reporter/NiV-M chimeric protein, we produced NiVLPs expressing NiV-G and wild-type or mutant NiV-F on their surfaces. By preloading target cells with the βLa fluorescent substrate CCF2-AM, we obtained viral entry kinetic curves that correlated with the NiV-F fusogenic phenotypes, validating NiVLPs as suitable viral entry kinetic tools and suggesting overall relatively slower viral entry than cell-cell fusion kinetics. Additionally, the proportions of F and G on individual NiVLPs and the extent of receptor-induced conformational changes in NiV-G were measured via flow virometry, allowing the proper interpretation of the viral entry kinetic phenotypes. The significance of these findings in the viral entry field extends beyond NiV to other paramyxoviruses and enveloped viruses. Virus-cell membrane fusion is essential for enveloped virus infections. However, mechanistic viral membrane fusion studies have predominantly

Characterization of Human and Murine T-Cell Immunoglobulin Mucin Domain 4 (TIM-4) IgV Domain Residues Critical for Ebola Virus Entry.

PubMed

Rhein, Bethany A; Brouillette, Rachel B; Schaack, Grace A; Chiorini, John A; Maury, Wendy

2016-07-01

Phosphatidylserine (PtdSer) receptors that are responsible for the clearance of dying cells have recently been found to mediate enveloped virus entry. Ebola virus (EBOV), a member of the Filoviridae family of viruses, utilizes PtdSer receptors for entry into target cells. The PtdSer receptors human and murine T-cell immunoglobulin mucin (TIM) domain proteins TIM-1 and TIM-4 mediate filovirus entry by binding to PtdSer on the virion surface via a conserved PtdSer binding pocket within the amino-terminal IgV domain. While the residues within the TIM-1 IgV domain that are important for EBOV entry are characterized, the molecular details of virion-TIM-4 interactions have yet to be investigated. As sequences and structural alignments of the TIM proteins suggest distinct differences in the TIM-1 and TIM-4 IgV domain structures, we sought to characterize TIM-4 IgV domain residues required for EBOV entry. Using vesicular stomatitis virus pseudovirions bearing EBOV glycoprotein (EBOV GP/VSVΔG), we evaluated virus binding and entry into cells expressing TIM-4 molecules mutated within the IgV domain, allowing us to identify residues important for entry. Similar to TIM-1, residues in the PtdSer binding pocket of murine and human TIM-4 (mTIM-4 and hTIM-4) were found to be important for EBOV entry. However, additional TIM-4-specific residues were also found to impact EBOV entry, with a total of 8 mTIM-4 and 14 hTIM-4 IgV domain residues being critical for virion binding and internalization. Together, these findings provide a greater understanding of the interaction of TIM-4 with EBOV virions. With more than 28,000 cases and over 11,000 deaths during the largest and most recent Ebola virus (EBOV) outbreak, there has been increased emphasis on the development of therapeutics against filoviruses. Many therapies under investigation target EBOV cell entry. T-cell immunoglobulin mucin (TIM) domain proteins are cell surface factors important for the entry of many enveloped viruses

Characterization of Human and Murine T-Cell Immunoglobulin Mucin Domain 4 (TIM-4) IgV Domain Residues Critical for Ebola Virus Entry

PubMed Central

Rhein, Bethany A.; Brouillette, Rachel B.; Schaack, Grace A.; Chiorini, John A.

2016-01-01

ABSTRACT Phosphatidylserine (PtdSer) receptors that are responsible for the clearance of dying cells have recently been found to mediate enveloped virus entry. Ebola virus (EBOV), a member of the Filoviridae family of viruses, utilizes PtdSer receptors for entry into target cells. The PtdSer receptors human and murine T-cell immunoglobulin mucin (TIM) domain proteins TIM-1 and TIM-4 mediate filovirus entry by binding to PtdSer on the virion surface via a conserved PtdSer binding pocket within the amino-terminal IgV domain. While the residues within the TIM-1 IgV domain that are important for EBOV entry are characterized, the molecular details of virion–TIM-4 interactions have yet to be investigated. As sequences and structural alignments of the TIM proteins suggest distinct differences in the TIM-1 and TIM-4 IgV domain structures, we sought to characterize TIM-4 IgV domain residues required for EBOV entry. Using vesicular stomatitis virus pseudovirions bearing EBOV glycoprotein (EBOV GP/VSVΔG), we evaluated virus binding and entry into cells expressing TIM-4 molecules mutated within the IgV domain, allowing us to identify residues important for entry. Similar to TIM-1, residues in the PtdSer binding pocket of murine and human TIM-4 (mTIM-4 and hTIM-4) were found to be important for EBOV entry. However, additional TIM-4-specific residues were also found to impact EBOV entry, with a total of 8 mTIM-4 and 14 hTIM-4 IgV domain residues being critical for virion binding and internalization. Together, these findings provide a greater understanding of the interaction of TIM-4 with EBOV virions. IMPORTANCE With more than 28,000 cases and over 11,000 deaths during the largest and most recent Ebola virus (EBOV) outbreak, there has been increased emphasis on the development of therapeutics against filoviruses. Many therapies under investigation target EBOV cell entry. T-cell immunoglobulin mucin (TIM) domain proteins are cell surface factors important for the entry of many

Binding of undamaged double stranded DNA to vaccinia virus uracil-DNA glycosylase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schormann, Norbert; Banerjee, Surajit; Ricciardi, Robert

Background: Uracil-DNA glycosylases are evolutionarily conserved DNA repair enzymes. However, vaccinia virus uracil-DNA glycosylase (known as D4), also serves as an intrinsic and essential component of the processive DNA polymerase complex during DNA replication. In this complex D4 binds to a unique poxvirus specific protein A20 which tethers it to the DNA polymerase. At the replication fork the DNA scanning and repair function of D4 is coupled with DNA replication. So far, DNA-binding to D4 has not been structurally characterized. Results: This manuscript describes the first structure of a DNA-complex of a uracil-DNA glycosylase from the poxvirus family. This alsomore » represents the first structure of a uracil DNA glycosylase in complex with an undamaged DNA. In the asymmetric unit two D4 subunits bind simultaneously to complementary strands of the DNA double helix. Each D4 subunit interacts mainly with the central region of one strand. DNA binds to the opposite side of the A20-binding surface on D4. In comparison of the present structure with the structure of uracil-containing DNA-bound human uracil-DNA glycosylase suggests that for DNA binding and uracil removal D4 employs a unique set of residues and motifs that are highly conserved within the poxvirus family but different in other organisms. Conclusion: The first structure of D4 bound to a truly non-specific undamaged double-stranded DNA suggests that initial binding of DNA may involve multiple non-specific interactions between the protein and the phosphate backbone.« less

Binding of undamaged double stranded DNA to vaccinia virus uracil-DNA glycosylase

DOE PAGES

Schormann, Norbert; Banerjee, Surajit; Ricciardi, Robert; ...

2015-06-02

Background: Uracil-DNA glycosylases are evolutionarily conserved DNA repair enzymes. However, vaccinia virus uracil-DNA glycosylase (known as D4), also serves as an intrinsic and essential component of the processive DNA polymerase complex during DNA replication. In this complex D4 binds to a unique poxvirus specific protein A20 which tethers it to the DNA polymerase. At the replication fork the DNA scanning and repair function of D4 is coupled with DNA replication. So far, DNA-binding to D4 has not been structurally characterized. Results: This manuscript describes the first structure of a DNA-complex of a uracil-DNA glycosylase from the poxvirus family. This alsomore » represents the first structure of a uracil DNA glycosylase in complex with an undamaged DNA. In the asymmetric unit two D4 subunits bind simultaneously to complementary strands of the DNA double helix. Each D4 subunit interacts mainly with the central region of one strand. DNA binds to the opposite side of the A20-binding surface on D4. In comparison of the present structure with the structure of uracil-containing DNA-bound human uracil-DNA glycosylase suggests that for DNA binding and uracil removal D4 employs a unique set of residues and motifs that are highly conserved within the poxvirus family but different in other organisms. Conclusion: The first structure of D4 bound to a truly non-specific undamaged double-stranded DNA suggests that initial binding of DNA may involve multiple non-specific interactions between the protein and the phosphate backbone.« less

Productive Entry of Foot-and-Mouth Disease Virus via Macropinocytosis Independent of Phosphatidylinositol 3-Kinase

PubMed Central

Han, Shi-Chong; Guo, Hui-Chen; Sun, Shi-Qi; Jin, Ye; Wei, Yan-Quan; Feng, Xia; Yao, Xue-Ping; Cao, Sui-Zhong; Xiang Liu, Ding; Liu, Xiang-Tao

2016-01-01

Virus entry is an attractive target for therapeutic intervention. Here, using a combination of electron microscopy, immunofluorescence assay, siRNA interference, specific pharmacological inhibitors, and dominant negative mutation, we demonstrated that the entry of foot-and-mouth disease virus (FMDV) triggered a substantial amount of plasma membrane ruffling. We also found that the internalization of FMDV induced a robust increase in fluid-phase uptake, and virions internalized within macropinosomes colocalized with phase uptake marker dextran. During this stage, the Rac1-Pak1 signaling pathway was activated. After specific inhibition on actin, Na+/H+ exchanger, receptor tyrosine kinase, Rac1, Pak1, myosin II, and protein kinase C, the entry and infection of FMDV significantly decreased. However, inhibition of phosphatidylinositol 3-kinase (PI3K) did not reduce FMDV internalization but increased the viral entry and infection to a certain extent, implying that FMDV entry did not require PI3K activity. Results showed that internalization of FMDV exhibited the main hallmarks of macropinocytosis. Moreover, intracellular trafficking of FMDV involves EEA1/Rab5-positive vesicles. The present study demonstrated macropinocytosis as another endocytic pathway apart from the clathrin-mediated pathway. The findings greatly expand our understanding of the molecular mechanisms of FMDV entry into cells, as well as provide potential insights into the entry mechanisms of other picornaviruses. PMID:26757826

Novel functional hepatitis C virus glycoprotein isolates identified using an optimized viral pseudotype entry assay.

PubMed

Urbanowicz, Richard A; McClure, C Patrick; King, Barnabas; Mason, Christopher P; Ball, Jonathan K; Tarr, Alexander W

2016-09-01

Retrovirus pseudotypes are a highly tractable model used to study the entry pathways of enveloped viruses. This model has been extensively applied to the study of the hepatitis C virus (HCV) entry pathway, preclinical screening of antiviral antibodies and for assessing the phenotype of patient-derived viruses using HCV pseudoparticles (HCVpp) possessing the HCV E1 and E2 glycoproteins. However, not all patient-isolated clones produce particles that are infectious in this model. This study investigated factors that might limit phenotyping of patient-isolated HCV glycoproteins. Genetically related HCV glycoproteins from quasispecies in individual patients were discovered to behave very differently in this entry model. Empirical optimization of the ratio of packaging construct and glycoprotein-encoding plasmid was required for successful HCVpp genesis for different clones. The selection of retroviral packaging construct also influenced the function of HCV pseudoparticles. Some glycoprotein constructs tolerated a wide range of assay parameters, while others were much more sensitive to alterations. Furthermore, glycoproteins previously characterized as unable to mediate entry were found to be functional. These findings were validated using chimeric cell-cultured HCV bearing these glycoproteins. Using the same empirical approach we demonstrated that generation of infectious ebolavirus pseudoviruses (EBOVpv) was also sensitive to the amount and ratio of plasmids used, and that protocols for optimal production of these pseudoviruses are dependent on the exact virus glycoprotein construct. These findings demonstrate that it is crucial for studies utilizing pseudoviruses to conduct empirical optimization of pseudotype production for each specific glycoprotein sequence to achieve optimal titres and facilitate accurate phenotyping.

[Behavior of Orf virus in permissive and nonpermissive systems].

PubMed

Büttner, M; Czerny, C P; Schumm, M

1995-04-01

Dogs were immunized i.m. with attenuated poxvirus vaccines (vaccinia virus, Orf-virus) and a bovine herpesvirus-1 (BHV-1) vaccine. After intradermal (i.d.) application of the vaccine viruses a specific delayed type hypersensitivity (DTH) reaction of the skin occurred only with vaccinia virus. The i.d. application of Orf-virus caused a short-term, non-specific inflammatory reaction of the skin, even in dogs not immunized with Orf-virus. Out of 30 sera from Orf-virus immunized beagles (n = 4) only eight were found reactive to Orf-virus in a competition ELISA. Three sera from dogs not Orf-virus immunized but skin-tested with the virus contained low antibody titers. Using indirect immunofluorescence (IIF) in flow cytometry, the existence of Orf-virus antigens was examined on the surface and in the cytoplasm of permissive (BFK and Vero)- and questionable permissive MDCK cells. The canine kidney MDCK cell line was found to be non-permissive for Orf-virus replication; the occurrence of an Orf-(ecthyma contagiosum) like disease in dogs is unlikely.

Oral vaccination of wildlife using a vaccinia-rabies-glycoprotein recombinant virus vaccine (RABORAL V-RG®): a global review.

PubMed

Maki, Joanne; Guiot, Anne-Laure; Aubert, Michel; Brochier, Bernard; Cliquet, Florence; Hanlon, Cathleen A; King, Roni; Oertli, Ernest H; Rupprecht, Charles E; Schumacher, Caroline; Slate, Dennis; Yakobson, Boris; Wohlers, Anne; Lankau, Emily W

2017-09-22

RABORAL V-RG ® is an oral rabies vaccine bait that contains an attenuated ("modified-live") recombinant vaccinia virus vector vaccine expressing the rabies virus glycoprotein gene (V-RG). Approximately 250 million doses have been distributed globally since 1987 without any reports of adverse reactions in wildlife or domestic animals since the first licensed recombinant oral rabies vaccine (ORV) was released into the environment to immunize wildlife populations against rabies. V-RG is genetically stable, is not detected in the oral cavity beyond 48 h after ingestion, is not shed by vaccinates into the environment, and has been tested for thermostability under a range of laboratory and field conditions. Safety of V-RG has been evaluated in over 50 vertebrate species, including non-human primates, with no adverse effects observed regardless of route or dose. Immunogenicity and efficacy have been demonstrated under laboratory and field conditions in multiple target species (including fox, raccoon, coyote, skunk, raccoon dog, and jackal). The liquid vaccine is packaged inside edible baits (i.e., RABORAL V-RG, the vaccine-bait product) which are distributed into wildlife habitats for consumption by target species. Field application of RABORAL V-RG has contributed to the elimination of wildlife rabies from three European countries (Belgium, France and Luxembourg) and of the dog/coyote rabies virus variant from the United States of America (USA). An oral rabies vaccination program in west-central Texas has essentially eliminated the gray fox rabies virus variant from Texas with the last case reported in a cow during 2009. A long-term ORV barrier program in the USA using RABORAL V-RG is preventing substantial geographic expansion of the raccoon rabies virus variant. RABORAL V-RG has also been used to control wildlife rabies in Israel for more than a decade. This paper: (1) reviews the development and historical use of RABORAL V-RG; (2) highlights wildlife rabies control

Transmission of vaccinia virus, possibly through sexual contact, to a woman at high risk for adverse complications.

PubMed

Said, Maria A; Haile, Charles; Palabindala, Venkataraman; Barker, Naomi; Myers, Robert; Thompson, Ruth; Wilson, Lucy; Allan-Martinez, Frances; Montgomery, Jay; Monroe, Benjamin; Tack, Danielle; Reynolds, Mary; Damon, Inger; Blythe, David

2013-12-01

Severe adverse events, including eczema vaccinatum (EV), can result after smallpox vaccination. Persons at risk for EV include those with underlying dermatologic conditions, such as atopic dermatitis. We investigated a case of vaccinia infection, possibly acquired during sexual contact with a recently vaccinated military service member, in a female Maryland resident with atopic dermatitis. The U.S. Department of Defense's Vaccine Healthcare Centers Network (VHCN) and the Centers for Disease Control and Prevention (CDC) worked in conjunction with the patient's physician and the Maryland Department of Health and Mental Hygiene (DHMH) to confirm the diagnosis, ensure treatment, and prevent further transmission. Specimens collected from the patient were tested at the DHMH laboratories and were positive by real-time polymerase chain reaction for nonvariola orthopoxvirus. Testing at the CDC verified the presence of vaccinia-specific DNA signatures. Continuing spread of the patient's lesions led to the administration of vaccinia immune globulin and strict infection control measures to prevent tertiary transmission to vulnerable family members, also with atopic dermatitis. VHCN contacted the service member to reinforce vaccination site care and hygiene. This case underscores the importance of prevaccination education for those receiving the smallpox vaccine to protect contacts at risk for developing severe adverse reactions. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.

Expression of Glycoproteins in Wild-Type and Vaccine Strains of Varicella Zoster Virus

DTIC Science & Technology

1990-06-18

gpV vaccinia recombinants 142 XI LIST OF FIGURES ^ig^rfi Page 1 . Structural model of the herpesvirus virion 8 2. A diagram of the VZV and HSV ...gpIV-specific antiserum 139 36. Fc receptor activity in HSV - 1 and VZV glycoprotein recombinant vaccinia viruses 145 37. The gene 14 transcription...subfamily alphaherpesvirinae. The human alphaherpesviruses are comprised of VZV and herpes simplex viruses 1 and 2 ( HSV - 1 and HSV -2). Four other

Linear Epitopes in Vaccinia Virus A27 Are Targets of Protective Antibodies Induced by Vaccination against Smallpox.

PubMed

Kaever, Thomas; Matho, Michael H; Meng, Xiangzhi; Crickard, Lindsay; Schlossman, Andrew; Xiang, Yan; Crotty, Shane; Peters, Bjoern; Zajonc, Dirk M

2016-05-01

Vaccinia virus (VACV) A27 is a target for viral neutralization and part of the Dryvax smallpox vaccine. A27 is one of the three glycosaminoglycan (GAG) adhesion molecules and binds to heparan sulfate. To understand the function of anti-A27 antibodies, especially their protective capacity and their interaction with A27, we generated and subsequently characterized 7 murine monoclonal antibodies (MAbs), which fell into 4 distinct epitope groups (groups I to IV). The MAbs in three groups (groups I, III, and IV) bound to linear peptides, while the MAbs in group II bound only to VACV lysate and recombinant A27, suggesting that they recognized a conformational and discontinuous epitope. Only group I antibodies neutralized the mature virion in a complement-dependent manner and protected against VACV challenge, while a group II MAb partially protected against VACV challenge but did not neutralize the mature virion. The epitope for group I MAbs was mapped to a region adjacent to the GAG binding site, a finding which suggests that group I MAbs could potentially interfere with the cellular adhesion of A27. We further determined the crystal structure of the neutralizing group I MAb 1G6, as well as the nonneutralizing group IV MAb 8E3, bound to the corresponding linear epitope-containing peptides. Both the light and the heavy chains of the antibodies are important in binding to their antigens. For both antibodies, the L1 loop seems to dominate the overall polar interactions with the antigen, while for MAb 8E3, the light chain generally appears to make more contacts with the antigen. Vaccinia virus is a powerful model to study antibody responses upon vaccination, since its use as the smallpox vaccine led to the eradication of one of the world's greatest killers. The immunodominant antigens that elicit the protective antibodies are known, yet for many of these antigens, little information about their precise interaction with antibodies is available. In an attempt to better

Smallpox and live-virus vaccination in transplant recipients.

PubMed

Fishman, Jay A

2003-07-01

Recent bioterrorism raises the specter of reemergence of smallpox as a clinical entity. The mortality of variola major infection ('typical smallpox') was approximately 30% in past outbreaks. Programs for smallpox immunization for healthcare workers have been proposed. Atypical forms of smallpox presenting with flat or hemorrhagic skin lesions are most common in individuals with immune deficits with historic mortality approaching 100%. Smallpox vaccination, even after exposure, is highly effective. Smallpox vaccine contains a highly immunogenic live virus, vaccinia. Few data exist for the impact of variola or safety of vaccinia in immunocompromised hosts. Both disseminated infection by vaccinia and person-to-person spread after vaccination are uncommon. When it occurs, secondary vaccinia has usually affected individuals with pre-existing skin conditions (atopic dermatitis or eczema) or with other underlying immune deficits. Historically, disseminated vaccinia infection was uncommon but often fatal even in the absence of the most severe form of disease, "progressive vaccinia". Some responded to vaccinia immune globulin. Smallpox exposure would be likely to cause significant mortality among immunocompromised hosts. In the absence of documented smallpox exposures, immunocompromised hosts should not be vaccinated against smallpox. Planning for bioterrorist events must include consideration of uniquely susceptible hosts.

NTCP and Beyond: Opening the Door to Unveil Hepatitis B Virus Entry

PubMed Central

Watashi, Koichi; Urban, Stephan; Li, Wenhui; Wakita, Takaji

2014-01-01

Chronic hepatitis B virus (HBV) infection, affecting approximately 240 million people worldwide, is a major public health problem that elevates the risk of developing liver cirrhosis and hepatocellular carcinoma. Given that current anti-HBV drugs are limited to interferon-based regimens and nucleos(t)ide analogs, the development of new anti-HBV agents is urgently needed. The viral entry process is generally an attractive target implicated in antiviral strategies. Using primary cells from humans and Tupaia belangeri, as well as HepaRG cells, important determinants of viral entry have been achieved. Recently, sodium taurocholate cotransporting polypeptide (NTCP) was identified as an HBV entry receptor and enabled the establishment of a susceptible cell line that can efficiently support HBV infection. This finding will allow a deeper understanding of the requirements for efficient HBV infection, including the elucidation of the molecular entry mechanism. In addition, pharmacological studies suggest that NTCP is able to serve as a therapeutic target. This article summarizes our current knowledge on the mechanisms of HBV entry and the role of NTCP in this process. PMID:24557582

NTCP and beyond: opening the door to unveil hepatitis B virus entry.

PubMed

Watashi, Koichi; Urban, Stephan; Li, Wenhui; Wakita, Takaji

2014-02-19

Chronic hepatitis B virus (HBV) infection, affecting approximately 240 million people worldwide, is a major public health problem that elevates the risk of developing liver cirrhosis and hepatocellular carcinoma. Given that current anti-HBV drugs are limited to interferon-based regimens and nucleos(t)ide analogs, the development of new anti-HBV agents is urgently needed. The viral entry process is generally an attractive target implicated in antiviral strategies. Using primary cells from humans and Tupaia belangeri, as well as HepaRG cells, important determinants of viral entry have been achieved. Recently, sodium taurocholate cotransporting polypeptide (NTCP) was identified as an HBV entry receptor and enabled the establishment of a susceptible cell line that can efficiently support HBV infection. This finding will allow a deeper understanding of the requirements for efficient HBV infection, including the elucidation of the molecular entry mechanism. In addition, pharmacological studies suggest that NTCP is able to serve as a therapeutic target. This article summarizes our current knowledge on the mechanisms of HBV entry and the role of NTCP in this process.

A dormant internal ribosome entry site controls translation of feline immunodeficiency virus.

PubMed

Camerini, Valentina; Decimo, Didier; Balvay, Laurent; Pistello, Mauro; Bendinelli, Mauro; Darlix, Jean-Luc; Ohlmann, Théophile

2008-04-01

The characterization of internal ribosome entry sites (IRESs) in virtually all lentiviruses prompted us to investigate the mechanism used by the feline immunodeficiency virus (FIV) to produce viral proteins. Various in vitro translation assays with mono- and bicistronic constructs revealed that translation of the FIV genomic RNA occurred both by a cap-dependent mechanism and by weak internal entry of the ribosomes. This weak IRES activity was confirmed in feline cells expressing bicistronic RNAs containing the FIV 5' untranslated region (UTR). Surprisingly, infection of feline cells with FIV, but not human immunodeficiency virus type 1, resulted in a great increase in FIV translation. Moreover, a change in the cellular physiological condition provoked by heat stress resulted in the specific stimulation of expression driven by the FIV 5' UTR while cap-dependent initiation was severely repressed. These results reveal the presence of a "dormant" IRES that becomes activated by viral infection and cellular stress.

A Chimeric HIV-1 gp120 Fused with Vaccinia Virus 14K (A27) Protein as an HIV Immunogen

PubMed Central

Vijayan, Aneesh; García-Arriaza, Juan; C. Raman, Suresh; Conesa, José Javier; Chichón, Francisco Javier; Santiago, César; Sorzano, Carlos Óscar S.; Carrascosa, José L.; Esteban, Mariano

2015-01-01

In the HIV vaccine field, there is a need to produce highly immunogenic forms of the Env protein with the capacity to trigger broad B and T-cell responses. Here, we report the generation and characterization of a chimeric HIV-1 gp120 protein (termed gp120-14K) by fusing gp120 from clade B with the vaccinia virus (VACV) 14K oligomeric protein (derived from A27L gene). Stable CHO cell lines expressing HIV-1 gp120-14K protein were generated and the protein purified was characterized by size exclusion chromatography, electron microscopy and binding to anti-Env antibodies. These approaches indicate that gp120-14K protein is oligomeric and reacts with a wide spectrum of HIV-1 neutralizing antibodies. Furthermore, in human monocyte-derived dendritic cells (moDCs), gp120-14K protein upregulates the levels of several proinflammatory cytokines and chemokines associated with Th1 innate immune responses (IL-1β, IFN-γ, IL-6, IL-8, IL-12, RANTES). Moreover, we showed in a murine model, that a heterologous prime/boost immunization protocol consisting of a DNA prime with a plasmid expressing gp120-14K protein followed by a boost with MVA-B [a recombinant modified vaccinia virus Ankara (MVA) expressing HIV-1 gp120, Gag, Pol and Nef antigens from clade B], generates stronger, more polyfunctional, and greater effector memory HIV-1-specific CD4+ and CD8+ T-cell immune responses, than immunization with DNA-gp120/MVA-B. The DNA/MVA protocol was superior to immunization with the combination of protein/MVA and the latter was superior to a prime/boost of MVA/MVA or protein/protein. In addition, these immunization protocols enhanced antibody responses against gp120 of the class IgG2a and IgG3, together favoring a Th1 humoral immune response. These results demonstrate that fusing HIV-1 gp120 with VACV 14K forms an oligomeric protein which is highly antigenic as it activates a Th1 innate immune response in human moDCs, and in vaccinated mice triggers polyfunctional HIV-1-specific adaptive

Disruption of TNFα/TNFR1 function in resident skin cells impairs host immune response against cutaneous vaccinia virus infection

PubMed Central

Tian, Tian; Dubin, Krista; Jin, Qiushuang; Qureshi, Ali; King, Sandra L.; Liu, Luzheng; Jiang, Xiaodong; Murphy, George F.; Kupper, Thomas S.; Fuhlbrigge, Robert C.

2012-01-01

One strategy adopted by vaccinia virus (VV) to evade the host immune system is to encode homologs of TNF receptors (TNFR) that block TNFα function. The response to VV skin infection under conditions of TNFα deficiency, however, has not been reported. We found that TNFR1−/− mice developed larger primary lesions, numerous satellite lesions and higher skin virus levels after VV scarification. Following their recovery, these TNFR1−/− mice were fully protected against challenge with a lethal intranasal dose of VV, suggesting these mice developed an effective memory immune response. A functional systemic immune response of TNFR1−/− mice was further demonstrated by enhanced production of VV-specific IFNγ and VV-specific CD8+ T cells in spleens and draining lymph nodes. Interestingly, bone marrow (BM) reconstitution studies using WT BM in TNFR1−/− host mice, but not TNFR1−/− BM in WT host mice, reproduced the original results seen in TNFR1−/− mice, indicating that TNFR1 deficiency in resident skin cells, rather than hematopoietic cells, accounts for the impaired cutaneous immune response. Our data suggest that lack of TNFR1 leads to a skin-specific immune deficiency and that resident skin cells play a crucial role in mediating an optimal immune defense to VV cutaneous infection via TNFα/TNFR1 signaling. PMID:22318381

Spontaneous Mutation at Amino Acid 544 of the Ebola Virus Glycoprotein Potentiates Virus Entry and Selection in Tissue Culture.

PubMed

Ruedas, John B; Ladner, Jason T; Ettinger, Chelsea R; Gummuluru, Suryaram; Palacios, Gustavo; Connor, John H

2017-08-01

Ebolaviruses have a surface glycoprotein (GP 1,2 ) that is required for virus attachment and entry into cells. Mutations affecting GP 1,2 functions can alter virus growth properties. We generated a recombinant vesicular stomatitis virus encoding Ebola virus Makona variant GP 1,2 (rVSV-MAK-GP) and observed emergence of a T544I mutation in the Makona GP 1,2 gene during tissue culture passage in certain cell lines. The T544I mutation emerged within two passages when VSV-MAK-GP was grown on Vero E6, Vero, and BS-C-1 cells but not when it was passaged on Huh7 and HepG2 cells. The mutation led to a marked increase in virus growth kinetics and conferred a robust growth advantage over wild-type rVSV-MAK-GP on Vero E6 cells. Analysis of complete viral genomes collected from patients in western Africa indicated that this mutation was not found in Ebola virus clinical samples. However, we observed the emergence of T544I during serial passage of various Ebola Makona isolates on Vero E6 cells. Three independent isolates showed emergence of T544I from undetectable levels in nonpassaged virus or virus passaged once to frequencies of greater than 60% within a single passage, consistent with it being a tissue culture adaptation. Intriguingly, T544I is not found in any Sudan, Bundibugyo, or Tai Forest ebolavirus sequences. Furthermore, T544I did not emerge when we serially passaged recombinant VSV encoding GP 1,2 from these ebolaviruses. This report provides experimental evidence that the spontaneous mutation T544I is a tissue culture adaptation in certain cell lines and that it may be unique for the species Zaire ebolavirus IMPORTANCE The Ebola virus (Zaire) species is the most lethal species of all ebolaviruses in terms of mortality rate and number of deaths. Understanding how the Ebola virus surface glycoprotein functions to facilitate entry in cells is an area of intense research. Recently, three groups independently identified a polymorphism in the Ebola glycoprotein (I544

Spontaneous Mutation at Amino Acid 544 of the Ebola Virus Glycoprotein Potentiates Virus Entry and Selection in Tissue Culture

PubMed Central

Ladner, Jason T.; Ettinger, Chelsea R.; Palacios, Gustavo

2017-01-01

ABSTRACT Ebolaviruses have a surface glycoprotein (GP1,2) that is required for virus attachment and entry into cells. Mutations affecting GP1,2 functions can alter virus growth properties. We generated a recombinant vesicular stomatitis virus encoding Ebola virus Makona variant GP1,2 (rVSV-MAK-GP) and observed emergence of a T544I mutation in the Makona GP1,2 gene during tissue culture passage in certain cell lines. The T544I mutation emerged within two passages when VSV-MAK-GP was grown on Vero E6, Vero, and BS-C-1 cells but not when it was passaged on Huh7 and HepG2 cells. The mutation led to a marked increase in virus growth kinetics and conferred a robust growth advantage over wild-type rVSV-MAK-GP on Vero E6 cells. Analysis of complete viral genomes collected from patients in western Africa indicated that this mutation was not found in Ebola virus clinical samples. However, we observed the emergence of T544I during serial passage of various Ebola Makona isolates on Vero E6 cells. Three independent isolates showed emergence of T544I from undetectable levels in nonpassaged virus or virus passaged once to frequencies of greater than 60% within a single passage, consistent with it being a tissue culture adaptation. Intriguingly, T544I is not found in any Sudan, Bundibugyo, or Tai Forest ebolavirus sequences. Furthermore, T544I did not emerge when we serially passaged recombinant VSV encoding GP1,2 from these ebolaviruses. This report provides experimental evidence that the spontaneous mutation T544I is a tissue culture adaptation in certain cell lines and that it may be unique for the species Zaire ebolavirus. IMPORTANCE The Ebola virus (Zaire) species is the most lethal species of all ebolaviruses in terms of mortality rate and number of deaths. Understanding how the Ebola virus surface glycoprotein functions to facilitate entry in cells is an area of intense research. Recently, three groups independently identified a polymorphism in the Ebola glycoprotein (I544

Photodynamic therapy augments the efficacy of oncolytic vaccinia virus against primary and metastatic tumours in mice

PubMed Central

Gil, M; Bieniasz, M; Seshadri, M; Fisher, D; Ciesielski, M J; Chen, Y; Pandey, R K; Kozbor, D

2011-01-01

Background: Therapies targeted towards the tumour vasculature can be exploited for the purpose of improving the systemic delivery of oncolytic viruses to tumours. Photodynamic therapy (PDT) is a clinically approved treatment for cancer that is known to induce potent effects on tumour vasculature. In this study, we examined the activity of PDT in combination with oncolytic vaccinia virus (OVV) against primary and metastatic tumours in mice. Methods: The effect of 2-[1-hexyloxyethyl-]-2-devinyl pyropheophorbide-a (HPPH)-sensitised-PDT on the efficacy of oncolytic virotherapy was investigated against subcutaneously implanted syngeneic murine NXS2 neuroblastoma and human FaDu head and neck squamous cell carcinoma xenografts in nude mice. Treatment efficacy was evaluated by monitoring tumour growth and survival. The effects of combination treatment on vascular function were examined using magnetic resonance imaging (MRI) and immunohistochemistry, whereas viral replication in tumour cells was analysed by a standard plaque assay. Normal tissue phototoxicity following PDT-OV treatment was studied using the mouse foot response assay. Results: Combination of PDT with OVV resulted in inhibition of primary and metastatic tumour growth compared with either monotherapy. PDT-induced vascular disruption resulted in higher intratumoural viral titres compared with the untreated tumours. Five days after delivery of OVV, there was a loss of blood flow to the interior of tumour that was associated with infiltration of neutrophils. Administration of OVV did not result in any additional photodynamic damage to normal mouse foot tissue. Conclusion: These results provide evidence into the usefulness of PDT as a means of enhancing intratumoural replication and therapeutic efficacy of OV. PMID:21989183

HIV-1 gp120 and Modified Vaccinia Virus Ankara (MVA) gp140 Boost Immunogens Increase Immunogenicity of a DNA/MVA HIV-1 Vaccine.

PubMed

Shen, Xiaoying; Basu, Rahul; Sawant, Sheetal; Beaumont, David; Kwa, Sue Fen; LaBranche, Celia; Seaton, Kelly E; Yates, Nicole L; Montefiori, David C; Ferrari, Guido; Wyatt, Linda S; Moss, Bernard; Alam, S Munir; Haynes, Barton F; Tomaras, Georgia D; Robinson, Harriet L

2017-12-15

An important goal of human immunodeficiency virus (HIV) vaccine design is identification of strategies that elicit effective antiviral humoral immunity. One novel approach comprises priming with DNA and boosting with modified vaccinia virus Ankara (MVA) expressing HIV-1 Env on virus-like particles. In this study, we evaluated whether the addition of a gp120 protein in alum or MVA-expressed secreted gp140 (MVAgp140) could improve immunogenicity of a DNA prime-MVA boost vaccine. Five rhesus macaques per group received two DNA primes at weeks 0 and 8 followed by three MVA boosts (with or without additional protein or MVAgp140) at weeks 18, 26, and 40. Both boost immunogens enhanced the breadth of HIV-1 gp120 and V1V2 responses, antibody-dependent cellular cytotoxicity (ADCC), and low-titer tier 1B and tier 2 neutralizing antibody responses. However, there were differences in antibody kinetics, linear epitope specificity, and CD4 T cell responses between the groups. The gp120 protein boost elicited earlier and higher peak responses, whereas the MVAgp140 boost resulted in improved antibody durability and comparable peak responses after the final immunization. Linear V3 specific IgG responses were particularly enhanced by the gp120 boost, whereas the MVAgp140 boost also enhanced responses to linear C5 and C2.2 epitopes. Interestingly, gp120, but not the MVAgp140 boost, increased peak CD4 + T cell responses. Thus, both gp120 and MVAgp140 can augment potential protection of a DNA/MVA vaccine by enhancing gp120 and V1/V2 antibody responses, whereas potential protection by gp120, but not MVAgp140 boosts, may be further impacted by increased CD4 + T cell responses. IMPORTANCE Prior immune correlate analyses with humans and nonhuman primates revealed the importance of antibody responses in preventing HIV-1 infection. A DNA prime-modified vaccinia virus Ankara (MVA) boost vaccine has proven to be potent in eliciting antibody responses. Here we explore the ability of boosts with

Vaccinia virus recombinants encoding the truncated structural gene region of Venezuelan equine encephalitis virus (VEEV) give solid protection against peripheral challenge but only partial protection against airborne challenge with virulent VEEV.

PubMed

Phillpotts, R J; Lescott, T L; Jacobs, S C

2000-10-01

Vaccinia virus (VV) recombinants that contain the genes encoding the Venezuelan equine encephalitis virus (VEEV) structural gene region (C-E3-E2-6 K-E1) solidly protect mice against peripheral challenge with virulent VEEV, but provide only partial protection against airborne challenge. To improve upon these results we focussed on the principal antigens involved in protection. VV recombinants encoding the structural genes E3-E2-6 K-E1, E3-E2-6 K or 6 K-E1 were prepared and evaluated for their ability to protect Balb/c mice after a single dorsal scarification with 10(8) PFU against peripheral or airborne challenge with virulent VEEV. The antibody response was also examined. Our experiments provide new evidence that truncates of the VEEV structural region (E3-E2-6 K-E1, E3-E2-6 K), cloned and expressed in VV, protect against challenge with virulent virus. They also confirm the important role of E2 in protection. However, we were unable to improve upon previously reported levels of protection against airborne challenge. A substantial level of circulating antibodies and the presence of local IgA (not always induced by mucosal immunization) (Greenway et al., 1992) appear essential for protection against the airborne virus. Current VV-VEEV recombinants seem unable to elicit this level of immune response and further improvements are therefore required to increase the immunogenicity of VV-VEEV vaccines.

Molecular Determinants of Hepatitis B and D Virus Entry Restriction in Mouse Sodium Taurocholate Cotransporting Polypeptide

PubMed Central

Yan, Huan; Peng, Bo; He, Wenhui; Zhong, Guocai; Qi, Yonghe; Ren, Bijie; Gao, Zhenchao; Jing, Zhiyi; Song, Mei; Xu, Guangwei; Sui, Jianhua

2013-01-01

Human hepatitis B virus (HBV) and its satellite virus, hepatitis D virus (HDV), primarily infect humans, chimpanzees, or tree shrews (Tupaia belangeri). Viral infections in other species are known to be mainly restricted at the entry level since viral replication can be achieved in the cells by transfection of the viral genome. Sodium taurocholate cotransporting polypeptide (NTCP) is a functional receptor for HBV and HDV, and amino acids 157 to 165 of NTCP are critical for viral entry and likely limit viral infection of macaques. However, the molecular determinants for viral entry restriction in mouse NTCP (mNTCP) remain unclear. In this study, mNTCP was found to be unable to support either HBV or HDV infection, although it can bind to pre-S1 of HBV L protein and is functional in transporting substrate taurocholate; comprehensive swapping and point mutations of human NTCP (hNTCP) and mNTCP revealed molecular determinants restricting mNTCP for viral entry of HBV and HDV. Remarkably, when mNTCP residues 84 to 87 were substituted by human counterparts, mNTCP can effectively support viral infections. In addition, a number of cell lines, regardless of their species or tissue origin, supported HDV infection when transfected with hNTCP or mNTCP with residues 84 to 87 replaced by human counterparts, highlighting the central role of NTCP for viral infections mediated by HBV envelope proteins. These studies advance our understanding of NTCP-mediated viral entry of HBV and HDV and have important implications for developing the mouse model for their infections. PMID:23678176

Immunization with a Recombinant Vaccinia Virus That Encodes Nonstructural Proteins of the Hepatitis C Virus Suppresses Viral Protein Levels in Mouse Liver

PubMed Central

Sekiguchi, Satoshi; Kimura, Kiminori; Chiyo, Tomoko; Ohtsuki, Takahiro; Tobita, Yoshimi; Tokunaga, Yuko; Yasui, Fumihiko; Tsukiyama-Kohara, Kyoko; Wakita, Takaji; Tanaka, Toshiyuki; Miyasaka, Masayuki; Mizuno, Kyosuke; Hayashi, Yukiko; Hishima, Tsunekazu; Matsushima, Kouji; Kohara, Michinori

2012-01-01

Chronic hepatitis C, which is caused by infection with the hepatitis C virus (HCV), is a global health problem. Using a mouse model of hepatitis C, we examined the therapeutic effects of a recombinant vaccinia virus (rVV) that encodes an HCV protein. We generated immunocompetent mice that each expressed multiple HCV proteins via a Cre/loxP switching system and established several distinct attenuated rVV strains. The HCV core protein was expressed consistently in the liver after polyinosinic acid–polycytidylic acid injection, and these mice showed chronic hepatitis C-related pathological findings (hepatocyte abnormalities, accumulation of glycogen, steatosis), liver fibrosis, and hepatocellular carcinoma. Immunization with one rVV strain (rVV-N25), which encoded nonstructural HCV proteins, suppressed serum inflammatory cytokine levels and alleviated the symptoms of pathological chronic hepatitis C within 7 days after injection. Furthermore, HCV protein levels in liver tissue also decreased in a CD4 and CD8 T-cell-dependent manner. Consistent with these results, we showed that rVV-N25 immunization induced a robust CD8 T-cell immune response that was specific to the HCV nonstructural protein 2. We also demonstrated that the onset of chronic hepatitis in CN2-29(+/−)/MxCre(+/−) mice was mainly attributable to inflammatory cytokines, (tumor necrosis factor) TNF-α and (interleukin) IL-6. Thus, our generated mice model should be useful for further investigation of the immunological processes associated with persistent expression of HCV proteins because these mice had not developed immune tolerance to the HCV antigen. In addition, we propose that rVV-N25 could be developed as an effective therapeutic vaccine. PMID:23284733

Immunization with a recombinant vaccinia virus that encodes nonstructural proteins of the hepatitis C virus suppresses viral protein levels in mouse liver.

PubMed

Sekiguchi, Satoshi; Kimura, Kiminori; Chiyo, Tomoko; Ohtsuki, Takahiro; Tobita, Yoshimi; Tokunaga, Yuko; Yasui, Fumihiko; Tsukiyama-Kohara, Kyoko; Wakita, Takaji; Tanaka, Toshiyuki; Miyasaka, Masayuki; Mizuno, Kyosuke; Hayashi, Yukiko; Hishima, Tsunekazu; Matsushima, Kouji; Kohara, Michinori

2012-01-01

Chronic hepatitis C, which is caused by infection with the hepatitis C virus (HCV), is a global health problem. Using a mouse model of hepatitis C, we examined the therapeutic effects of a recombinant vaccinia virus (rVV) that encodes an HCV protein. We generated immunocompetent mice that each expressed multiple HCV proteins via a Cre/loxP switching system and established several distinct attenuated rVV strains. The HCV core protein was expressed consistently in the liver after polyinosinic acid-polycytidylic acid injection, and these mice showed chronic hepatitis C-related pathological findings (hepatocyte abnormalities, accumulation of glycogen, steatosis), liver fibrosis, and hepatocellular carcinoma. Immunization with one rVV strain (rVV-N25), which encoded nonstructural HCV proteins, suppressed serum inflammatory cytokine levels and alleviated the symptoms of pathological chronic hepatitis C within 7 days after injection. Furthermore, HCV protein levels in liver tissue also decreased in a CD4 and CD8 T-cell-dependent manner. Consistent with these results, we showed that rVV-N25 immunization induced a robust CD8 T-cell immune response that was specific to the HCV nonstructural protein 2. We also demonstrated that the onset of chronic hepatitis in CN2-29((+/-))/MxCre((+/-)) mice was mainly attributable to inflammatory cytokines, (tumor necrosis factor) TNF-α and (interleukin) IL-6. Thus, our generated mice model should be useful for further investigation of the immunological processes associated with persistent expression of HCV proteins because these mice had not developed immune tolerance to the HCV antigen. In addition, we propose that rVV-N25 could be developed as an effective therapeutic vaccine.

Determinants in the Ig Variable Domain of Human HAVCR1 (TIM-1) Are Required To Enhance Hepatitis C Virus Entry.

PubMed

Kachko, Alla; Costafreda, Maria Isabel; Zubkova, Iryna; Jacques, Jerome; Takeda, Kazuyo; Wells, Frances; Kaplan, Gerardo; Major, Marian E

2018-03-15

Hepatitis C virus (HCV) is the leading cause of chronic hepatitis in humans. Several host molecules participate in HCV cell entry, but this process remains unclear. The complete unraveling of the HCV entry process is important to further understand viral pathogenesis and develop therapeutics. Human hepatitis A virus (HAV) cellular receptor 1 (HAVCR1), CD365, also known as TIM-1, functions as a phospholipid receptor involved in cell entry of several enveloped viruses. Here, we studied the role of HAVCR1 in HCV infection. HAVCR1 antibody inhibited entry in a dose-dependent manner. HAVCR1 soluble constructs neutralized HCV, which did not require the HAVCR1 mucinlike region and was abrogated by a mutation of N to A at position 94 (N94A) in the Ig variable (IgV) domain phospholipid-binding pocket, indicating a direct interaction of the HAVCR1 IgV domain with HCV virions. However, knockout of HAVCR1 in Huh7 cells reduced but did not prevent HCV growth. Interestingly, the mouse HAVCR1 ortholog, also a phospholipid receptor, did not enhance infection and a soluble form failed to neutralize HCV, although replacement of the mouse IgV domain with the human HAVCR1 IgV domain restored the enhancement of HCV infection. Mutations in the cytoplasmic tail revealed that direct HAVCR1 signaling is not required to enhance HCV infection. Our data show that the phospholipid-binding function and other determinant(s) in the IgV domain of human HAVCR1 enhance HCV infection. Although the exact mechanism is not known, it is possible that HAVCR1 facilitates entry by stabilizing or enhancing attachment, leading to direct interactions with specific receptors, such as CD81. IMPORTANCE Hepatitis C virus (HCV) enters cells through a multifaceted process. We identified the human hepatitis A virus cellular receptor 1 (HAVCR1), CD365, also known as TIM-1, as a facilitator of HCV entry. Antibody blocking and silencing or knockout of HAVCR1 in hepatoma cells reduced HCV entry. Our findings that the

Actin- and myosin-driven movement of viruses along filopodia precedes their entry into cells

PubMed Central

Lehmann, Maik J.; Sherer, Nathan M.; Marks, Carolyn B.; Pypaert, Marc; Mothes, Walther

2005-01-01

Viruses have often been observed in association with the dense microvilli of polarized epithelia as well as the filopodia of nonpolarized cells, yet whether interactions with these structures contribute to infection has remained unknown. Here we show that virus binding to filopodia induces a rapid and highly ordered lateral movement, “surfing” toward the cell body before cell entry. Virus cell surfing along filopodia is mediated by the underlying actin cytoskeleton and depends on functional myosin II. Any disruption of virus cell surfing significantly reduces viral infection. Our results reveal another example of viruses hijacking host machineries for efficient infection by using the inherent ability of filopodia to transport ligands to the cell body. PMID:16027225

Actin- and myosin-driven movement of viruses along filopodia precedes their entry into cells.

PubMed

Lehmann, Maik J; Sherer, Nathan M; Marks, Carolyn B; Pypaert, Marc; Mothes, Walther

2005-07-18

Viruses have often been observed in association with the dense microvilli of polarized epithelia as well as the filopodia of nonpolarized cells, yet whether interactions with these structures contribute to infection has remained unknown. Here we show that virus binding to filopodia induces a rapid and highly ordered lateral movement, "surfing" toward the cell body before cell entry. Virus cell surfing along filopodia is mediated by the underlying actin cytoskeleton and depends on functional myosin II. Any disruption of virus cell surfing significantly reduces viral infection. Our results reveal another example of viruses hijacking host machineries for efficient infection by using the inherent ability of filopodia to transport ligands to the cell body.

Preventing vaccinia virus class-I epitopes presentation by HSV-ICP47 enhances the immunogenicity of a TAP-independent cancer vaccine epitope.

PubMed

Raafat, Nermin; Sadowski-Cron, Charlotte; Mengus, Chantal; Heberer, Michael; Spagnoli, Giulio C; Zajac, Paul

2012-09-01

Herpes simplex virus protein ICP47, encoded by US12 gene, strongly downregulates major histocompatibility complex (MHC) class-I antigen restricted presentation by blocking transporter associated with antigen processing (TAP) protein. To decrease viral vector antigenic immunodominance and MHC class-I driven clearance, we engineered recombinant vaccinia viruses (rVV) expressing ICP47 alone (rVV-US12) or together with endoplasmic reticulum (ER)-targeted Melan-A/MART-1(27-35) model tumor epitope (rVV-MUS12). In this study, we show that antigen presenting cells (APC), infected with rVV-US12, display a decreased ability to present TAP dependent MHC class-I restricted viral antigens to CD8+ T-cells. While HLA class-I cell surface expression is strongly downregulated, other important immune related molecules such as CD80, CD44 and, most importantly, MHC class-II are unaffected. Characterization of rVV-MUS12 infected cells demonstrates that over-expression of a TAP-independent peptide, partially compensates for ICP47 induced surface MHC class-I downregulation (30% vs. 70% respectively). Most importantly, in conditions where clearance of infected APC by virus-specific CTL represents a limiting factor, a significant enhancement of CTL responses to the tumor epitope can be detected in cultures stimulated with rVV-MUS12, as compared to those stimulated by rVV-MART alone. Such reagents could become of high relevance in multiple boost protocols required for cancer immunotherapy, to limit vector-specific responsiveness. Copyright © 2011 UICC.

Comparative Analysis of Host Cell Entry of Ebola Virus From Sierra Leone, 2014, and Zaire, 1976.

PubMed

Hofmann-Winkler, Heike; Gnirß, Kerstin; Wrensch, Florian; Pöhlmann, Stefan

2015-10-01

The ongoing Ebola virus (EBOV) disease (EVD) epidemic in Western Africa is the largest EVD outbreak recorded to date and requires the rapid development and deployment of antiviral measures. The viral glycoprotein (GP) facilitates host cell entry and, jointly with cellular interaction partners, constitutes a potential target for antiviral intervention. However, it is unknown whether the GPs of the currently and previously circulating EBOVs use the same mechanisms for cellular entry and are thus susceptible to inhibition by the same antivirals and cellular defenses. Here, we show that the GPs of the EBOVs circulating in 1976 and 2014 transduce the same spectrum of target cells, use the same cellular factors for host cell entry, and are comparably susceptible to blockade by antiviral interferon-induced transmembrane proteins and neutralizing antibody KZ52. Thus, the viruses responsible for the ongoing EVD epidemic should be fully susceptible to established antiviral strategies targeting GP and cellular entry factors. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

Infection of Mouse Macrophages by Seasonal Influenza Viruses Can Be Restricted at the Level of Virus Entry and at a Late Stage in the Virus Life Cycle

PubMed Central

Londrigan, Sarah L.; Short, Kirsty R.; Ma, Joel; Gillespie, Leah; Rockman, Steven P.; Brooks, Andrew G.

2015-01-01

ABSTRACT Airway epithelial cells are susceptible to infection with seasonal influenza A viruses (IAV), resulting in productive virus replication and release. Macrophages (MΦ) are also permissive to IAV infection; however, virus replication is abortive. Currently, it is unclear how productive infection of MΦ is impaired or the extent to which seasonal IAV replicate in MΦ. Herein, we compared mouse MΦ and epithelial cells for their ability to support genomic replication and transcription, synthesis of viral proteins, assembly of virions, and release of infectious progeny following exposure to genetically defined IAV. We confirm that seasonal IAV differ in their ability to utilize cell surface receptors for infectious entry and that this represents one level of virus restriction. Following virus entry, we demonstrate synthesis of all eight segments of genomic viral RNA (vRNA) and mRNA, as well as seven distinct IAV proteins, in IAV-infected mouse MΦ. Although newly synthesized hemagglutinin (HA) and neuraminidase (NA) glycoproteins are incorporated into the plasma membrane and expressed at the cell surface, electron microscopy confirmed that virus assembly was defective in IAV-infected MΦ, defining a second level of restriction late in the virus life cycle. IMPORTANCE Seasonal influenza A viruses (IAV) and highly pathogenic avian influenza viruses (HPAI) infect macrophages, but only HPAI replicate productively in these cells. Herein, we demonstrate that impaired virus uptake into macrophages represents one level of restriction limiting infection by seasonal IAV. Following uptake, seasonal IAV do not complete productive replication in macrophages, representing a second level of restriction. Using murine macrophages, we demonstrate that productive infection is blocked late in the virus life cycle, such that virus assembly is defective and newly synthesized virions are not released. These studies represent an important step toward identifying host-encoded factors

Infection of Mouse Macrophages by Seasonal Influenza Viruses Can Be Restricted at the Level of Virus Entry and at a Late Stage in the Virus Life Cycle.

PubMed

Londrigan, Sarah L; Short, Kirsty R; Ma, Joel; Gillespie, Leah; Rockman, Steven P; Brooks, Andrew G; Reading, Patrick C

2015-12-01

Airway epithelial cells are susceptible to infection with seasonal influenza A viruses (IAV), resulting in productive virus replication and release. Macrophages (MΦ) are also permissive to IAV infection; however, virus replication is abortive. Currently, it is unclear how productive infection of MΦ is impaired or the extent to which seasonal IAV replicate in MΦ. Herein, we compared mouse MΦ and epithelial cells for their ability to support genomic replication and transcription, synthesis of viral proteins, assembly of virions, and release of infectious progeny following exposure to genetically defined IAV. We confirm that seasonal IAV differ in their ability to utilize cell surface receptors for infectious entry and that this represents one level of virus restriction. Following virus entry, we demonstrate synthesis of all eight segments of genomic viral RNA (vRNA) and mRNA, as well as seven distinct IAV proteins, in IAV-infected mouse MΦ. Although newly synthesized hemagglutinin (HA) and neuraminidase (NA) glycoproteins are incorporated into the plasma membrane and expressed at the cell surface, electron microscopy confirmed that virus assembly was defective in IAV-infected MΦ, defining a second level of restriction late in the virus life cycle. Seasonal influenza A viruses (IAV) and highly pathogenic avian influenza viruses (HPAI) infect macrophages, but only HPAI replicate productively in these cells. Herein, we demonstrate that impaired virus uptake into macrophages represents one level of restriction limiting infection by seasonal IAV. Following uptake, seasonal IAV do not complete productive replication in macrophages, representing a second level of restriction. Using murine macrophages, we demonstrate that productive infection is blocked late in the virus life cycle, such that virus assembly is defective and newly synthesized virions are not released. These studies represent an important step toward identifying host-encoded factors that block

Regression of Established Human Papillomavirus Type 16 (HPV-16) Immortalized Tumors In Vivo by Vaccinia Viruses Expressing Different Forms of HPV-16 E7 Correlates with Enhanced CD8+ T-Cell Responses That Home to the Tumor Site

PubMed Central

Lamikanra, Abigail; Pan, Zhen-Kun; Isaacs, Stuart N.; Wu, Tzyy-Choou; Paterson, Yvonne

2001-01-01

Using vaccinia virus as a live vector, we show that the expression of human papillomavirus type 16 (HPV-16) E7 fused to a nonhemolytic portion of the Listeria monocytogenes virulence factor, listeriolysin O (LLO), induces an immune response that causes the regression of established HPV-16 immortalized tumors in C57BL/6 mice. The vaccinia virus construct expressing LLO fused to E7 (VacLLOE7) was compared with two previously described vaccinia virus constructs: one that expresses unmodified E7 (VacE7) and another that expresses E7 in a form designed to direct it to intracellular lysosomal compartments and improve major histocompatibility complex class II-restricted responses (VacSigE7LAMP-1). C57BL/6 mice bearing established HPV-16 immortalized tumors of 5 or 8 mm were treated with each of these vaccines. Fifty percent of the mice treated with VacLLOE7 remained tumor free 2 months after tumor inoculation, whereas 12 to 25% of the mice were tumor free after treatment with VacSigE7LAMP-1 (depending on the size of the tumor). No mice were tumor free in the group given VacE7. Compared to VacE7, VacSigE7LAMP-1 and VacLLOE7 resulted in increased numbers of H2-Db-specific tetramer-positive CD8+ T cells in mouse spleens that produced gamma interferon and tumor necrosis factor alpha upon stimulation with RAHYNIVTF peptide. In addition, the highest frequency of tetramer-positive T cells was seen in the tumor sites of mice treated with VacLLOE7. An increased efficiency of E7-specific lysis by splenocytes from mice immunized with VacLLOE7 was also observed. These results indicate that the fusion of E7 with LLO not only enhances antitumor therapy by improving the tumoricidal function of E7-specific CD8+ T cells but may also increase the number of antigen-specific CD8+ T cells in the tumor, the principle site of antigen expression. PMID:11559797

Prediction of Steps in the Evolution of Variola Virus Host Range

PubMed Central

Smithson, Chad; Purdy, Alex; Verster, Adrian J.; Upton, Chris

2014-01-01

Variola virus, the agent of smallpox, has a severely restricted host range (humans) but a devastatingly high mortality rate. Although smallpox has been eradicated by a World Health Organization vaccination program, knowledge of the evolutionary processes by which human super-pathogens such as variola virus arise is important. By analyzing the evolution of variola and other closely related poxviruses at the level of single nucleotide polymorphisms we detected a hotspot of genome variation within the smallpox ortholog of the vaccinia virus O1L gene, which is known to be necessary for efficient replication of vaccinia virus in human cells. These mutations in the variola virus ortholog and the subsequent loss of the functional gene from camelpox virus and taterapox virus, the two closest relatives of variola virus, strongly suggest that changes within this region of the genome may have played a key role in the switch to humans as a host for the ancestral virus and the subsequent host-range restriction that must have occurred to create the phenotype exhibited by smallpox. PMID:24626337

Prediction of steps in the evolution of variola virus host range.

PubMed

Smithson, Chad; Purdy, Alex; Verster, Adrian J; Upton, Chris

2014-01-01

Variola virus, the agent of smallpox, has a severely restricted host range (humans) but a devastatingly high mortality rate. Although smallpox has been eradicated by a World Health Organization vaccination program, knowledge of the evolutionary processes by which human super-pathogens such as variola virus arise is important. By analyzing the evolution of variola and other closely related poxviruses at the level of single nucleotide polymorphisms we detected a hotspot of genome variation within the smallpox ortholog of the vaccinia virus O1L gene, which is known to be necessary for efficient replication of vaccinia virus in human cells. These mutations in the variola virus ortholog and the subsequent loss of the functional gene from camelpox virus and taterapox virus, the two closest relatives of variola virus, strongly suggest that changes within this region of the genome may have played a key role in the switch to humans as a host for the ancestral virus and the subsequent host-range restriction that must have occurred to create the phenotype exhibited by smallpox.

Vaccine and Wild-Type Strains of Yellow Fever Virus Engage Distinct Entry Mechanisms and Differentially Stimulate Antiviral Immune Responses.

PubMed

Fernandez-Garcia, Maria Dolores; Meertens, Laurent; Chazal, Maxime; Hafirassou, Mohamed Lamine; Dejarnac, Ophélie; Zamborlini, Alessia; Despres, Philippe; Sauvonnet, Nathalie; Arenzana-Seisdedos, Fernando; Jouvenet, Nolwenn; Amara, Ali

2016-02-09

The live attenuated yellow fever virus (YFV) vaccine 17D stands as a "gold standard" for a successful vaccine. 17D was developed empirically by passaging the wild-type Asibi strain in mouse and chicken embryo tissues. Despite its immense success, the molecular determinants for virulence attenuation and immunogenicity of the 17D vaccine are poorly understood. 17D evolved several mutations in its genome, most of which lie within the envelope (E) protein. Given the major role played by the YFV E protein during virus entry, it has been hypothesized that the residues that diverge between the Asibi and 17D E proteins may be key determinants of attenuation. In this study, we define the process of YFV entry into target cells and investigate its implication in the activation of the antiviral cytokine response. We found that Asibi infects host cells exclusively via the classical clathrin-mediated endocytosis, while 17D exploits a clathrin-independent pathway for infectious entry. We demonstrate that the mutations in the 17D E protein acquired during the attenuation process are sufficient to explain the differential entry of Asibi versus 17D. Interestingly, we show that 17D binds to and infects host cells more efficiently than Asibi, which culminates in increased delivery of viral RNA into the cytosol and robust activation of the cytokine-mediated antiviral response. Overall, our study reveals that 17D vaccine and Asibi enter target cells through distinct mechanisms and highlights a link between 17D attenuation, virus entry, and immune activation. The yellow fever virus (YFV) vaccine 17D is one of the safest and most effective live virus vaccines ever developed. The molecular determinants for virulence attenuation and immunogenicity of 17D are poorly understood. 17D was generated by serially passaging the virulent Asibi strain in vertebrate tissues. Here we examined the entry mechanisms engaged by YFV Asibi and the 17D vaccine. We found the two viruses use different entry

Novel Roles of Focal Adhesion Kinase in Cytoplasmic Entry and Replication of Influenza A Viruses

PubMed Central

Cline, Troy; Baranovich, Tatiana; Govorkova, Elena A.; Schultz-Cherry, Stacey

2014-01-01

ABSTRACT Viruses modulate cellular signaling pathways at almost every step of the infection cycle. Cellular signaling pathways activated at later times of influenza infection have previously been investigated; however, early influenza virus-host cell interactions remain understudied. Focal adhesion kinase (FAK) is a cytoplasmic tyrosine kinase that regulates phosphatidylinositol 3-kinase (PI3K) activation and actin reorganization, two critical processes during influenza A virus (IAV) infection in most cell types. Using 6 influenza A virus strains (A/Puerto Rico/8/1934, A/Aichi/2/1968 × A/Puerto Rico/8/1934 reassortant [X-31], A/California/04/2009, mouse-adapted A/California/04/2009, A/WSN/1933, and A/New Caledonia/20/1999), we examined the role of FAK during IAV entry. We found that influenza virus attachment induced PI3K-dependent FAK-Y397 phosphorylation. Pharmacological FAK inhibition or expression of a kinase-dead mutant of FAK led to disruption of the actin meshwork that resulted in sequestration of IAV at the cell periphery and reduced virion localization to early endosomes. Additionally, FAK inhibition impeded viral RNA replication at later times of infection and ultimately resulted in significantly reduced viral titers in both A549 and differentiated normal human bronchial epithelial (NHBE) cells. Although not all tested strains activated FAK, all of them exhibited a reduction in viral replication in response to inhibition of FAK signaling. These findings highlight novel biphasic roles of FAK activation during IAV infection and indicate that FAK serves as a central link between receptor-mediated PI3K activation and actin reorganization during IAV infection. IMPORTANCE We found that FAK links early activation of PI3K and actin reorganization, thereby regulating influenza virus entry. Surprisingly, we also found that FAK can regulate viral RNA replication independently of its role in entry. Our study addresses a knowledge gap in the understanding of

Postchallenge Administration of Brincidofovir Protects Healthy and Immune-Deficient Mice Reconstituted with Limited Numbers of T Cells from Lethal Challenge with IHD-J-Luc Vaccinia Virus

PubMed Central

McCullough, Kevin Tyler; Cruz, Stephanie; Thomas, Antonia; Diaz, Claudia G.; Keilholz, Laurie; Grossi, Irma M.; Trost, Lawrence C.; Golding, Hana

2015-01-01

ABSTRACT Protection from lethality by postchallenge administration of brincidofovir (BCV, CMX001) was studied in normal and immune-deficient (nude, nu/nu) BALB/c mice infected with vaccinia virus (VACV). Whole-body bioluminescence imaging was used to record total fluxes in the nasal cavity, lungs, spleen, and liver and to enumerate pox lesions on tails of mice infected via the intranasal route with 105 PFU of recombinant IHD-J-Luc VACV expressing luciferase. Areas under the flux curve (AUCs) were calculated for individual mice to assess viral loads. A three-dose regimen of 20 mg/kg BCV administered every 48 h starting either on day 1 or day 2 postchallenge protected 100% of mice. Initiating BCV treatment earlier was more efficient in reducing viral loads and in providing protection from pox lesion development. All BCV-treated mice that survived challenge were also protected from rechallenge with IHD-J-Luc or WRvFire VACV without additional treatment. In immune-deficient mice, BCV protected animals from lethality and reduced viral loads while animals were on the drug. Viral recrudescence occurred within 4 to 9 days, and mice succumbed ∼10 to 20 days after treatment termination. Nude mice reconstituted with 105 T cells prior to challenge with 104 PFU of IHD-J-Luc and treated with BCV postchallenge survived the infection, cleared the virus from all organs, and survived rechallenge with 105 PFU of IHD-J-Luc VACV without additional BCV treatment. Together, these data suggest that BCV protects immunocompetent and partially T cell-reconstituted immune-deficient mice from lethality, reduces viral dissemination in organs, prevents pox lesion development, and permits generation of VACV-specific memory. IMPORTANCE Mass vaccination is the primary element of the public health response to a smallpox outbreak. In addition to vaccination, however, antiviral drugs are required for individuals with uncertain exposure status to smallpox or for whom vaccination is contraindicated

Novel cyclo-peptides inhibit Ebola pseudotyped virus entry by targeting primed GP protein.

PubMed

Li, Quanjie; Ma, Ling; Yi, Dongrong; Wang, Han; Wang, Jing; Zhang, Yongxin; Guo, Ying; Li, Xiaoyu; Zhou, Jinming; Shi, Yi; Gao, George F; Cen, Shan

2018-07-01

Ebola virus (EBOV) causes fatal hemorrhagic fever with high death rates in human. Currently, there are no available clinically-approved prophylactic or therapeutic treatments. The recently solved crystal structure of cleavage-primed EBOV glycoprotein (GPcl) in complex with the C domain of endosomal protein Niemann-Pick C1 (NPC1) provides a new target for the development of EBOV entry inhibitors. In this work, a computational approach using docking and molecular dynamic simulations is carried out for the rational design of peptide inhibitors. A novel cyclo-peptide (Pep-3.3) was identified to target at the late stage of EBOV entry and exhibit specific inhibitory activity against EBOV-GP pseudotyped viruses, with 50% inhibitory concentration (IC50) of 5.1 μM. In vitro binding assay and molecular simulations revealed that Pep-3.3 binds to GPcl with a KD value of 69.7 μM, through interacting with predicted residues in the hydrophobic binding pocket of GPcl. Mutation of predicted residues T83 caused resistance to Pep-3.3 inhibition in viral infectivity, providing preliminary support for the model of the peptide binding to GPcl. This study demonstrates the feasibility of inhibiting EBOV entry by targeting GPcl with peptides. Copyright © 2018 Elsevier B.V. All rights reserved.

Inactivation of Viruses by Benzalkonium Chloride

PubMed Central

Armstrong, J. A.; Froelich, E. J.

1964-01-01

Benzalkonium chloride (as Roccal or Zephiran) was found to inactivate influenza, measles, canine distemper, rabies, fowl laryngotracheitis, vaccinia, Semliki Forest, feline pneumonitis, meningopneumonitis, and herpes simplex viruses after 10 min of exposure at 30 C or at room temperature. Poliovirus and encephalomyocarditis virus were not inactivated under the same conditions. It was concluded that all viruses tested were sensitive except members of the picorna group. The literature was reviewed. PMID:4288740

African Swine Fever Virus Gets Undressed: New Insights on the Entry Pathway.

PubMed

Andrés, Germán

2017-02-15

African swine fever virus (ASFV) is a large, multienveloped DNA virus composed of a genome-containing core successively wrapped by an inner lipid envelope, an icosahedral protein capsid, and an outer lipid envelope. In keeping with this structural complexity, recent studies have revealed an intricate entry program. This Gem highlights how ASFV uses two alternative pathways, macropinocytosis and clathrin-mediated endocytosis, to enter into the host macrophage and how the endocytosed particles undergo a stepwise, low pH-driven disassembly leading to inner envelope fusion and core delivery in the cytoplasm. Copyright © 2017 American Society for Microbiology.

Multiple Cationic Amphiphiles Induce a Niemann-Pick C Phenotype and Inhibit Ebola Virus Entry and Infection

PubMed Central

Shoemaker, Charles J.; Schornberg, Kathryn L.; Delos, Sue E.; Scully, Corinne; Pajouhesh, Hassan; Olinger, Gene G.; Johansen, Lisa M.; White, Judith M.

2013-01-01

Ebola virus (EBOV) is an enveloped RNA virus that causes hemorrhagic fever in humans and non-human primates. Infection requires internalization from the cell surface and trafficking to a late endocytic compartment, where viral fusion occurs, providing a conduit for the viral genome to enter the cytoplasm and initiate replication. In a concurrent study, we identified clomiphene as a potent inhibitor of EBOV entry. Here, we screened eleven inhibitors that target the same biosynthetic pathway as clomiphene. From this screen we identified six compounds, including U18666A, that block EBOV infection (IC50 1.6 to 8.0 µM) at a late stage of entry. Intriguingly, all six are cationic amphiphiles that share additional chemical features. U18666A induces phenotypes, including cholesterol accumulation in endosomes, associated with defects in Niemann–Pick C1 protein (NPC1), a late endosomal and lysosomal protein required for EBOV entry. We tested and found that all six EBOV entry inhibitors from our screen induced cholesterol accumulation. We further showed that higher concentrations of cationic amphiphiles are required to inhibit EBOV entry into cells that overexpress NPC1 than parental cells, supporting the contention that they inhibit EBOV entry in an NPC1-dependent manner. A previously reported inhibitor, compound 3.47, inhibits EBOV entry by blocking binding of the EBOV glycoprotein to NPC1. None of the cationic amphiphiles tested had this effect. Hence, multiple cationic amphiphiles (including several FDA approved agents) inhibit EBOV entry in an NPC1-dependent fashion, but by a mechanism distinct from that of compound 3.47. Our findings suggest that there are minimally two ways of perturbing NPC1-dependent pathways that can block EBOV entry, increasing the attractiveness of NPC1 as an anti-filoviral therapeutic target. PMID:23441171

Parainfluenza virus 5-based vaccine vectors expressing vaccinia virus (VACV) antigens provide long-term protection in mice from lethal intranasal VACV challenge.

PubMed

Clark, Kimberly M; Johnson, John B; Kock, Nancy D; Mizel, Steven B; Parks, Griffith D

2011-10-25

To test the potential for parainfluenza virus 5 (PIV5)-based vectors to provide protection from vaccinia virus (VACV) infection, PIV5 was engineered to express secreted VACV L1R and B5R proteins, two important antigens for neutralization of intracellular mature (IMV) and extracellular enveloped (EEV) virions, respectively. Protection of mice from lethal intranasal VACV challenge required intranasal immunization with PIV5-L1R/B5R in a prime-boost protocol, and correlated with low VACV-induced pathology in the respiratory tract and anti-VACV neutralizing antibody. Mice immunized with PIV5-L1R/B5R showed some disease symptoms following VACV challenge such as loss of weight and hunching, but these symptoms were delayed and less severe than with unimmunized control mice. While immunization with PIV5 expressing B5R alone conferred at least some protection, the most effective immunization included the PIV5 vector expressing L1R alone or in combination with PIV5-B5R. PIV5-L1R/B5R vectors elicited protection from VACV challenge even when CD8+ cells were depleted, but not in the case of mice that were defective in B cell production. Mice were protected from VACV challenge out to at least 1.5 years after immunization with PIV5-L1R/B5R vectors, and showed significant levels of anti-VACV neutralizing antibodies. These results demonstrate the potential for PIV5-based vectors to provide long lasting protection against complex human respiratory pathogens such as VACV, but also highlight the need to understand mechanisms for the generation of strong immune responses against poorly immunogenic viral proteins. Copyright © 2011 Elsevier Inc. All rights reserved.

Identification of Cell Surface Molecules Involved in Dystroglycan-Independent Lassa Virus Cell Entry

PubMed Central

Ströher, Ute; Ebihara, Hideki; Feldmann, Heinz

2012-01-01

Although O-mannosylated dystroglycan is a receptor for Lassa virus, a causative agent of Lassa fever, recent findings suggest the existence of an alternative receptor(s). Here we identified four molecules as receptors for Lassa virus: Axl and Tyro3, from the TAM family, and dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) and liver and lymph node sinusoidal endothelial calcium-dependent lectin (LSECtin), from the C-type lectin family. These molecules enhanced the binding of Lassa virus to cells and mediated infection independently of dystroglycan. Axl- or Tyro3-mediated infection required intracellular signaling via the tyrosine kinase activity of Axl or Tyro3, whereas DC-SIGN- or LSECtin-mediated infection and binding were dependent on a specific carbohydrate and on ions. The identification of these four molecules as Lassa virus receptors advances our understanding of Lassa virus cell entry. PMID:22156524

Generation of herpesvirus entry mediator (HVEM)-restricted herpes simplex virus type 1 mutant viruses: resistance of HVEM-expressing cells and identification of mutations that rescue nectin-1 recognition.

PubMed

Uchida, Hiroaki; Shah, Waris A; Ozuer, Ali; Frampton, Arthur R; Goins, William F; Grandi, Paola; Cohen, Justus B; Glorioso, Joseph C

2009-04-01

Both initial infection and cell-to-cell spread by herpes simplex virus type 1 (HSV-1) require the interaction of the viral glycoprotein D (gD) with an entry receptor on the cell surface. The two major HSV entry receptors, herpesvirus entry mediator (HVEM) and nectin-1, mediate infection independently but are coexpressed on a variety of cells. To determine if both receptors are active in these instances, we have established mutant viruses that are selectively impaired for recognition of one or the other receptor. In plaque assays, these viruses showed approximately 1,000-fold selectivity for the matched receptor over the mismatched receptor. Separate assays showed that each virus is impaired for both infection and spread through the mismatched receptor. We tested several human tumor cell lines for susceptibility to these viruses and observed that HT29 colon carcinoma cells are susceptible to infection by nectin-1-restricted virus but are highly resistant to HVEM-restricted virus infection, despite readily detectable HVEM expression on the cell surface. HVEM cDNA isolated from HT29 cells rendered HSV-resistant cells permissive for infection by the HVEM-restricted virus, suggesting that HT29 cells lack a cofactor for HVEM-mediated infection or express an HVEM-specific inhibitory factor. Passaging of HVEM-restricted virus on nectin-1-expressing cells yielded a set of gD missense mutations that each restored functional recognition of nectin-1. These mutations identify residues that likely play a role in shaping the nectin-1 binding site of gD. Our findings illustrate the utility of these receptor-restricted viruses in studying the early events in HSV infection.

C-peptide inhibitors of Ebola virus glycoprotein-mediated cell entry: effects of conjugation to cholesterol and side chain-side chain crosslinking.

PubMed

Higgins, Chelsea D; Koellhoffer, Jayne F; Chandran, Kartik; Lai, Jonathan R

2013-10-01

We previously described potent inhibition of Ebola virus entry by a 'C-peptide' based on the GP2 C-heptad repeat region (CHR) targeted to endosomes ('Tat-Ebo'). Here, we report the synthesis and evaluation of C-peptides conjugated to cholesterol, and Tat-Ebo analogs containing covalent side chain-side chain crosslinks to promote α-helical conformation. We found that the cholesterol-conjugated C-peptides were potent inhibitors of Ebola virus glycoprotein (GP)-mediated cell entry (~10(3)-fold reduction in infection at 40 μM). However, this mechanism of inhibition is somewhat non-specific because the cholesterol-conjugated peptides also inhibited cell entry mediated by vesicular stomatitis virus glycoprotein G. One side chain-side chain crosslinked peptide had moderately higher activity than the parent compound Tat-Ebo. Circular dichroism revealed that the cholesterol-conjugated peptides unexpectedly formed a strong α-helical conformation that was independent of concentration. Side chain-side chain crosslinking enhanced α-helical stability of the Tat-Ebo variants, but only at neutral pH. These result provide insight into mechanisms of C-peptide inhibiton of Ebola virus GP-mediated cell entry. Copyright © 2013 Elsevier Ltd. All rights reserved.

Reversible Inactivation and Desiccation Tolerance of Silicified Viruses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laidler, James J.; Shugart, Jessica A.; Cady, Sherry L.

2013-11-19

Long-distance host-independent virus dispersal is poorly understood, especially for viruses found in isolated ecosystems. To demonstrate a possible dispersal mechanism, we show that bacteriophage T4, archaeal virus SSV-K and Vaccinia are reversibly inactivated by mineralization in silica under conditions similar to volcanic hot springs. By contrast, bacteriophage PRD1 is not silicified. Moreover silicification provides viruses with remarkable desiccation resistance, which could allow extensive aerial dispersal.

Vaccinia Virus Protein C6 Inhibits Type I IFN Signalling in the Nucleus and Binds to the Transactivation Domain of STAT2.

PubMed

Stuart, Jennifer H; Sumner, Rebecca P; Lu, Yongxu; Snowden, Joseph S; Smith, Geoffrey L

2016-12-01

The type I interferon (IFN) response is a crucial innate immune signalling pathway required for defense against viral infection. Accordingly, the great majority of mammalian viruses possess means to inhibit this important host immune response. Here we show that vaccinia virus (VACV) strain Western Reserve protein C6, is a dual function protein that inhibits the cellular response to type I IFNs in addition to its published function as an inhibitor of IRF-3 activation, thereby restricting type I IFN production from infected cells. Ectopic expression of C6 inhibits the induction of interferon stimulated genes (ISGs) in response to IFNα treatment at both the mRNA and protein level. C6 inhibits the IFNα-induced Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway at a late stage, downstream of STAT1 and STAT2 phosphorylation, nuclear translocation and binding of the interferon stimulated gene factor 3 (ISGF3) complex to the interferon stimulated response element (ISRE). Mechanistically, C6 associates with the transactivation domain of STAT2 and this might explain how C6 inhibits the type I IFN signalling very late in the pathway. During virus infection C6 reduces ISRE-dependent gene expression despite the presence of the viral protein phosphatase VH1 that dephosphorylates STAT1 and STAT2. The ability of a cytoplasmic replicating virus to dampen the immune response within the nucleus, and the ability of viral immunomodulators such as C6 to inhibit multiple stages of the innate immune response by distinct mechanisms, emphasizes the intricacies of host-pathogen interactions and viral immune evasion.

Vaccinia Virus Blocks Stat1-Dependent and Stat1-Independent Gene Expression Induced by Type I and Type II Interferons

PubMed Central

Mann, Brandon A.; Huang, Julia He; Li, Ping; Chang, Hua-Chen; Slee, Roger B.; O'Sullivan, Audrey; Mathur, Anita; Yeh, Norman; Klemsz, Michael J.; Brutkiewicz, Randy R.; Blum, Janice S.

2008-01-01

Blocking the function of Stat (signal transducer and activator of transcription) proteins, which are critical for antiviral responses, has evolved as a common mechanism for pathogen immune evasion. The poxvirus-encoded phosphatase H1 is critical for viral replication, and may play an additional role in the evasion of host defense by dephosphorylating Stat1 and blocking interferon (IFN)-stimulated innate immune responses. Vaccinia virus (VACV) H1 can inhibit the phosphorylation of the transcription factor Stat1 after IFN-γ stimulation of epithelial cells, greatly attenuating IFN-induced biological functions. In this study, we demonstrate that VACV infection is capable of inhibiting the phosphorylation of Stat1 and Stat2 after stimulation of fibroblasts or bone marrow-derived macrophages with either type I or type II IFNs, but did not inhibit the activation of Stat3 or Stat5 in either cell type. By using recombinant proteins for in vitro assays, we observe that variola virus H1 is more active than VACV H1, although it has similar selectivity for Stat targets. Differential effects of VACV infection were observed on the induction of IFN-stimulated genes, with complete inhibition of some genes by VACV infection, while others were less affected. Despite the IFN-γ-induced expression of some genes in VACV-infected cells, IFN-γ was unable to rescue the VACV-mediated inhibition of MHC class II antigen presentation. Moreover, VACV infection can affect the IFN-induced expression of Stat1-dependent and Stat1-independent genes, suggesting that the virus may target additional IFN-activated pathways. Thus, VACV targets multiple signaling pathways in the evasion of antiviral immune responses. PMID:18593332

Equine Rhinitis A Virus and Its Low pH Empty Particle: Clues Towards an Aphthovirus Entry Mechanism?

PubMed Central

Tuthill, Tobias J.; Harlos, Karl; Walter, Thomas S.; Knowles, Nick J.; Groppelli, Elisabetta; Rowlands, David J.; Stuart, David I.; Fry, Elizabeth E.

2009-01-01

Equine rhinitis A virus (ERAV) is closely related to foot-and-mouth disease virus (FMDV), belonging to the genus Aphthovirus of the Picornaviridae. How picornaviruses introduce their RNA genome into the cytoplasm of the host cell to initiate replication is unclear since they have no lipid envelope to facilitate fusion with cellular membranes. It has been thought that the dissociation of the FMDV particle into pentameric subunits at acidic pH is the mechanism for genome release during cell entry, but this raises the problem of how transfer across the endosome membrane of the genome might be facilitated. In contrast, most other picornaviruses form ‘altered’ particle intermediates (not reported for aphthoviruses) thought to induce membrane pores through which the genome can be transferred. Here we show that ERAV, like FMDV, dissociates into pentamers at mildly acidic pH but demonstrate that dissociation is preceded by the transient formation of empty 80S particles which have released their genome and may represent novel biologically relevant intermediates in the aphthovirus cell entry process. The crystal structures of the native ERAV virus and a low pH form have been determined via highly efficient crystallization and data collection strategies, required due to low virus yields. ERAV is closely similar to FMDV for VP2, VP3 and part of VP4 but VP1 diverges, to give a particle with a pitted surface, as seen in cardioviruses. The low pH particle has internal structure consistent with it representing a pre-dissociation cell entry intermediate. These results suggest a unified mechanism of picornavirus cell entry. PMID:19816570

Towards a universal vaccine for avian influenza: Protective efficacy of modified Vaccinia virus Ankara and Adenovirus vaccines expressing conserved influenza antigens in chickens challenged with low pathogenic avian influenza virus

PubMed Central

Boyd, Amy C.; Ruiz-Hernandez, Raul; Peroval, Marylene Y.; Carson, Connor; Balkissoon, Devanand; Staines, Karen; Turner, Alison V.; Hill, Adrian V.S.; Gilbert, Sarah C.; Butter, Colin

2013-01-01

Current vaccines targeting surface proteins can drive antigenic variation resulting either in the emergence of more highly pathogenic viruses or of antigenically distinct viruses that escape control by vaccination and thereby persist in the host population. Influenza vaccines typically target the highly mutable surface proteins and do not provide protection against heterologous challenge. Vaccines which induce immune responses against conserved influenza epitopes may confer protection against heterologous challenge. We report here the results of vaccination with recombinant modified Vaccinia virus Ankara (MVA) and Adenovirus (Ad) expressing a fusion construct of nucleoprotein and matrix protein (NP + M1). Prime and boost vaccination regimes were trialled in different ages of chicken and were found to be safe and immunogenic. Interferon-γ (IFN-γ) ELISpot was used to assess the cellular immune response post secondary vaccination. In ovo Ad prime followed by a 4 week post hatch MVA boost was identified as the most immunogenic regime in one outbred and two inbred lines of chicken. Following vaccination, one inbred line (C15I) was challenged with low pathogenic avian influenza (LPAI) H7N7 (A/Turkey/England/1977). Birds receiving a primary vaccination with Ad-NP + M1 and a secondary vaccination with MVA-NP + M1 exhibited reduced cloacal shedding as measured by plaque assay at 7 days post infection compared with birds vaccinated with recombinant viruses containing irrelevant antigen. This preliminary indication of efficacy demonstrates proof of concept in birds; induction of T cell responses in chickens by viral vectors containing internal influenza antigens may be a productive strategy for the development of vaccines to induce heterologous protection against influenza in poultry. PMID:23200938

ST-246 inhibits in vivo poxvirus dissemination, virus shedding, and systemic disease manifestation.

PubMed

Berhanu, Aklile; King, David S; Mosier, Stacie; Jordan, Robert; Jones, Kevin F; Hruby, Dennis E; Grosenbach, Douglas W

2009-12-01

Orthopoxvirus infections, such as smallpox, can lead to severe systemic disease and result in considerable morbidity and mortality in immunologically naïve individuals. Treatment with ST-246, a small-molecule inhibitor of virus egress, has been shown to provide protection against severe disease and death induced by several members of the poxvirus family, including vaccinia, variola, and monkeypox viruses. Here, we show that ST-246 treatment not only results in the significant inhibition of vaccinia virus dissemination from the site of inoculation to distal organs, such as the spleen and liver, but also reduces the viral load in organs targeted by the dissemination. In mice intranasally infected with vaccinia virus, virus shedding from the nasal and lung mucosa was significantly lower (approximately 22- and 528-fold, respectively) upon ST-246 treatment. Consequently, virus dissemination from the nasal site of replication to the lung also was dramatically reduced, as evidenced by a 179-fold difference in virus levels in nasal versus bronchoalveolar lavage. Furthermore, in ACAM2000-immunized mice, vaccination site swabs showed that ST-246 treatment results in a major (approximately 3,900-fold by day 21) reduction in virus detected at the outside surfaces of lesions. Taken together, these data suggest that ST-246 would play a dual protective role if used during a smallpox bioterrorist attack. First, ST-246 would provide therapeutic benefit by reducing the disease burden and lethality in infected individuals. Second, by reducing virus shedding from those prophylactically immunized with a smallpox vaccine or harboring variola virus infection, ST-246 could reduce the risk of virus transmission to susceptible contacts.

Single virus particle mass detection using microresonators with nanoscale thickness

NASA Astrophysics Data System (ADS)

Gupta, A.; Akin, D.; Bashir, R.

2004-03-01

In this letter, we present the microfabrication and application of arrays of silicon cantilever beams as microresonator sensors with nanoscale thickness to detect the mass of individual virus particles. The dimensions of the fabricated cantilever beams were in the range of 4-5 μm in length, 1-2 μm in width and 20-30 nm in thickness. The virus particles we used in the study were vaccinia virus, which is a member of the Poxviridae family and forms the basis of the smallpox vaccine. The frequency spectra of the cantilever beams, due to thermal and ambient noise, were measured using a laser Doppler vibrometer under ambient conditions. The change in resonant frequency as a function of the virus particle mass binding on the cantilever beam surface forms the basis of the detection scheme. We have demonstrated the detection of a single vaccinia virus particle with an average mass of 9.5 fg. These devices can be very useful as components of biosensors for the detection of airborne virus particles.

A parallel genome-wide RNAi screening strategy to identify host proteins important for entry of Marburg virus and H5N1 influenza virus.

PubMed

Cheng, Han; Koning, Katie; O'Hearn, Aileen; Wang, Minxiu; Rumschlag-Booms, Emily; Varhegyi, Elizabeth; Rong, Lijun

2015-11-24

Genome-wide RNAi screening has been widely used to identify host proteins involved in replication and infection of different viruses, and numerous host factors are implicated in the replication cycles of these viruses, demonstrating the power of this approach. However, discrepancies on target identification of the same viruses by different groups suggest that high throughput RNAi screening strategies need to be carefully designed, developed and optimized prior to the large scale screening. Two genome-wide RNAi screens were performed in parallel against the entry of pseudotyped Marburg viruses and avian influenza virus H5N1 utilizing an HIV-1 based surrogate system, to identify host factors which are important for virus entry. A comparative analysis approach was employed in data analysis, which alleviated systematic positional effects and reduced the false positive number of virus-specific hits. The parallel nature of the strategy allows us to easily identify the host factors for a specific virus with a greatly reduced number of false positives in the initial screen, which is one of the major problems with high throughput screening. The power of this strategy is illustrated by a genome-wide RNAi screen for identifying the host factors important for Marburg virus and/or avian influenza virus H5N1 as described in this study. This strategy is particularly useful for highly pathogenic viruses since pseudotyping allows us to perform high throughput screens in the biosafety level 2 (BSL-2) containment instead of the BSL-3 or BSL-4 for the infectious viruses, with alleviated safety concerns. The screening strategy together with the unique comparative analysis approach makes the data more suitable for hit selection and enables us to identify virus-specific hits with a much lower false positive rate.

Alphavirus entry into host cells.

PubMed

Vancini, Ricardo; Hernandez, Raquel; Brown, Dennis

2015-01-01

Viruses have evolved to exploit the vast complexity of cellular processes for their success within the host cell. The entry mechanisms of enveloped viruses (viruses with a surrounding outer lipid bilayer membrane) are usually classified as being either endocytotic or fusogenic. Different mechanisms have been proposed for Alphavirus entry and genome delivery. Indirect observations led to a general belief that enveloped viruses can infect cells either by protein-assisted fusion with the plasma membrane in a pH-independent manner or by endocytosis and fusion with the endocytic vacuole in a low-pH environment. The mechanism of Alphavirus penetration has been recently revisited using direct observation of the processes by electron microscopy under conditions of different temperatures and time progression. Under conditions nonpermissive for endocytosis or any vesicular transport, events occur which allow the entry of the virus genome into the cells. When drug inhibitors of cellular functions are used to prevent entry, only ionophores are found to significantly inhibit RNA delivery. Arboviruses are agents of significant human and animal disease; therefore, strategies to control infections are needed and include development of compounds which will block critical steps in the early infection events. It appears that current evidence points to an entry mechanism, in which alphaviruses infect cells by direct penetration of cell plasma membranes through a pore structure formed by virus and, possibly, host proteins. © 2015 Elsevier Inc. All rights reserved.

Preclinical Testing Oncolytic Vaccinia Virus Strain GLV-5b451 Expressing an Anti-VEGF Single-Chain Antibody for Canine Cancer Therapy

PubMed Central

Adelfinger, Marion; Bessler, Simon; Frentzen, Alexa; Cecil, Alexander; Langbein-Laugwitz, Johanna; Gentschev, Ivaylo; Szalay, Aladar A.

2015-01-01

Virotherapy on the basis of oncolytic vaccinia virus (VACV) strains is a novel approach for canine cancer therapy. Here we describe, for the first time, the characterization and the use of VACV strain GLV-5b451 expressing the anti-vascular endothelial growth factor (VEGF) single-chain antibody (scAb) GLAF-2 as therapeutic agent against different canine cancers. Cell culture data demonstrated that GLV-5b451 efficiently infected and destroyed all four tested canine cancer cell lines including: mammary carcinoma (MTH52c), mammary adenoma (ZMTH3), prostate carcinoma (CT1258), and soft tissue sarcoma (STSA-1). The GLV-5b451 virus-mediated production of GLAF-2 antibody was observed in all four cancer cell lines. In addition, this antibody specifically recognized canine VEGF. Finally, in canine soft tissue sarcoma (CSTS) xenografted mice, a single systemic administration of GLV-5b451 was found to be safe and led to anti-tumor effects resulting in the significant reduction and substantial long-term inhibition of tumor growth. A CD31-based immuno-staining showed significantly decreased neo-angiogenesis in GLV-5b451-treated tumors compared to the controls. In summary, these findings indicate that GLV-5b451 has potential for use as a therapeutic agent in the treatment of CSTS. PMID:26205404

Role of the Phosphatidylserine Receptor TIM-1 in Enveloped-Virus Entry

PubMed Central

Moller-Tank, Sven; Kondratowicz, Andrew S.; Davey, Robert A.; Rennert, Paul D.

2013-01-01

The cell surface receptor T cell immunoglobulin mucin domain 1 (TIM-1) dramatically enhances filovirus infection of epithelial cells. Here, we showed that key phosphatidylserine (PtdSer) binding residues of the TIM-1 IgV domain are critical for Ebola virus (EBOV) entry through direct interaction with PtdSer on the viral envelope. PtdSer liposomes but not phosphatidylcholine liposomes competed with TIM-1 for EBOV pseudovirion binding and transduction. Further, annexin V (AnxV) substituted for the TIM-1 IgV domain, supporting a PtdSer-dependent mechanism. Our findings suggest that TIM-1-dependent uptake of EBOV occurs by apoptotic mimicry. Additionally, TIM-1 enhanced infection of a wide range of enveloped viruses, including alphaviruses and a baculovirus. As further evidence of the critical role of enveloped-virion-associated PtdSer in TIM-1-mediated uptake, TIM-1 enhanced internalization of pseudovirions and virus-like proteins (VLPs) lacking a glycoprotein, providing evidence that TIM-1 and PtdSer-binding receptors can mediate virus uptake independent of a glycoprotein. These results provide evidence for a broad role of TIM-1 as a PtdSer-binding receptor that mediates enveloped-virus uptake. Utilization of PtdSer-binding receptors may explain the wide tropism of many of these viruses and provide new avenues for controlling their virulence. PMID:23698310

Syncytial Mutations Do Not Impair the Specificity of Entry and Spread of a Glycoprotein D Receptor-Retargeted Herpes Simplex Virus

PubMed Central

Okubo, Yu; Wakata, Aika; Suzuki, Takuma; Shibata, Tomoko; Ikeda, Hitomi; Yamaguchi, Miki; Cohen, Justus B.; Glorioso, Joseph C.; Tagaya, Mitsuo; Hamada, Hirofumi; Tahara, Hideaki

2016-01-01

ABSTRACT Membrane fusion, which is the key process for both initial cell entry and subsequent lateral spread of herpes simplex virus (HSV), requires the four envelope glycoproteins gB, gD, gH, and gL. Syncytial mutations, predominantly mapped to the gB and gK genes, confer hyperfusogenicity on HSV and cause multinucleated giant cells, termed syncytia. Here we asked whether interaction of gD with a cognate entry receptor remains indispensable for initiating membrane fusion of syncytial strains. To address this question, we took advantage of mutant viruses whose viral entry into cells relies on the uniquely specific interaction of an engineered gD with epidermal growth factor receptor (EGFR). We introduced selected syncytial mutations into gB and/or gK of the EGFR-retargeted HSV and found that these mutations, especially when combined, enabled formation of extensive syncytia by human cancer cell lines that express the target receptor; these syncytia were substantially larger than the plaques formed by the parental retargeted HSV strain. We assessed the EGFR dependence of entry and spread separately by using direct entry and infectious center assays, respectively, and we found that the syncytial mutations did not override the receptor specificity of the retargeted viruses at either stage. We discuss the implications of these results for the development of more effective targeted oncolytic HSV vectors. IMPORTANCE Herpes simplex virus (HSV) is investigated not only as a human pathogen but also as a promising agent for oncolytic virotherapy. We previously showed that both the initial entry and subsequent lateral spread of HSV can be retargeted to cells expressing tumor-associated antigens by single-chain antibodies fused to a receptor-binding-deficient envelope glycoprotein D (gD). Here we introduced syncytial mutations into the gB and/or gK gene of gD-retargeted HSVs to determine whether viral tropism remained dependent on the interaction of gD with the target receptor

ACAM2000 clonal Vero cell culture vaccinia virus (New York City Board of Health strain)--a second-generation smallpox vaccine for biological defense.

PubMed

Monath, Thomas P; Caldwell, Joseph R; Mundt, Wolfgang; Fusco, Joan; Johnson, Casey S; Buller, Mark; Liu, Jian; Gardner, Bridget; Downing, Greg; Blum, Paul S; Kemp, Tracy; Nichols, Richard; Weltzin, Richard

2004-10-01

The threat of smallpox as a biological weapon has spurred efforts to create stockpiles of vaccine for emergency preparedness. In lieu of preparing vaccine in animal skin (the original method), we cloned vaccinia virus (New York City Board of Health strain, Dryvax by plaque purification and amplified the clone in cell culture. The overarching goal was to produce a modern vaccine that was equivalent to the currently licensed Dryvax in its preclinical and clinical properties, and could thus reliably protect humans against smallpox. A variety of clones were evaluated, and many were unacceptably virulent in animal models. One clonal virus (ACAM1000) was selected and produced at clinical grade in MRC-5 human diploid cells. ACAM1000 was comparable to Dryvax in immunogenicity and protective activity but was less neurovirulent for mice and nonhuman primates. To meet requirements for large quantities of vaccine after the events of September 11th 2001, the ACAM1000 master virus seed was used to prepare vaccine (designated ACAM2000) at large scale in Vero cells under serum-free conditions. The genomes of ACAM1000 and ACAM2000 had identical nucleotide sequences, and the vaccines had comparable biological phenotypes. ACAM1000 and ACAM2000 were evaluated in three Phase 1 clinical trials. The vaccines produced major cutaneous reactions and evoked neutralizing antibody and cell-mediated immune responses in the vast majority of subjects and had a reactogenicity profile similar to that of Dryvax.

The mature virion of ectromelia virus, a pathogenic poxvirus, is capable of intrahepatic spread and can serve as a target for delayed therapy.

PubMed

Ma, Xueying; Xu, Ren-Huan; Roscoe, Felicia; Whitbeck, J Charles; Eisenberg, Roselyn J; Cohen, Gary H; Sigal, Luis J

2013-06-01

Orthopoxviruses (OPVs), which include the agent of smallpox (variola virus), the zoonotic monkeypox virus, the vaccine and zoonotic species vaccinia virus, and the mouse pathogen ectromelia virus (ECTV), form two types of infectious viral particles: the mature virus (MV), which is cytosolic, and the enveloped virus (EV), which is extracellular. It is believed that MVs are required for viral entry into the host, while EVs are responsible for spread within the host. Following footpad infection of susceptible mice, ECTV spreads lymphohematogenously, entering the liver at 3 to 4 days postinfection (dpi). Afterwards, ECTV spreads intrahepatically, killing the host. We found that antibodies to an MV protein were highly effective at curing mice from ECTV infection when administered after the virus reached the liver. Moreover, a mutant ECTV that does not make EV was able to spread intrahepatically and kill immunodeficient mice. Together, these findings indicate that MVs are sufficient for the spread of ECTV within the liver and could have implications regarding the pathogenesis of other OPVs, the treatment of emerging OPV infections, as well as strategies for preparedness in case of accidental or intentional release of pathogenic OPVs.

Role of mannose-6-phosphate receptors in herpes simplex virus entry into cells and cell-to-cell transmission.

PubMed Central

Brunetti, C R; Burke, R L; Hoflack, B; Ludwig, T; Dingwell, K S; Johnson, D C

1995-01-01

Herpes simplex virus (HSV) glycoprotein D (gD) is essential for virus entry into cells, is modified with mannose-6-phosphate (M-6-P), and binds to both the 275-kDa M-6-P receptor (MPR) and the 46-kDa MPR (C. R. Brunetti, R. L. Burke, S. Kornfeld, W. Gregory, K. S. Dingwell, F. Masiarz, and D. C. Johnson, J. Biol. Chem. 269:17067-17074, 1994). Since MPRs are found on the surfaces of mammalian cells, we tested the hypothesis that MPRs could serve as receptors for HSV during virus entry into cells. A soluble form of the 275-kDa MPR, derived from fetal bovine serum, inhibited HSV plaques on monkey Vero cells, as did polyclonal rabbit anti-MPR antibodies. In addition, the number and size of HSV plaques were reduced when cells were treated with bovine serum albumin conjugated with pentamannose-phosphate (PM-PO4-BSA), a bulky ligand which can serve as a high-affinity ligand for MPRs. These data imply that HSV can use MPRs to enter cells; however, other molecules must also serve as receptors for HSV because a reasonable fraction of virus could enter cells treated with even the highest concentrations of these inhibitors. Consistent with the possibility that there are other receptors, HSV produced the same number of plaques on MPR-deficient mouse fibroblasts as were produced on normal mouse fibroblasts, but there was no inhibition with PM-PO4-BSA with either of these embryonic mouse cells. Together, these results demonstrate that HSV does not rely solely on MPRs to enter cells, although MPRs apparently play some role in virus entry into some cell types and, perhaps, act as one of a number of cell surface molecules that can facilitate entry. We also found that HSV produced small plaques on human fibroblasts derived from patients with pseudo-Hurler's polydystrophy, cells in which glycoproteins are not modified with M-6-P residues and yet production of infectious HSV particles was not altered in the pseudo-Hurler cells. In addition, HSV plaque size was reduced by PM-PO4-BSA

Vaccinia virus proteins A36 and F12/E2 show strong preferences for different kinesin light chain isoforms.

PubMed

Gao, William N D; Carpentier, David C J; Ewles, Helen A; Lee, Stacey-Ann; Smith, Geoffrey L

2017-08-01

Vaccinia virus (VACV) utilizes microtubule-mediated trafficking at several stages of its life cycle, of which virus egress is the most intensely studied. During egress VACV proteins A36, F12 and E2 are involved in kinesin-1 interactions; however, the roles of these proteins remain poorly understood. A36 forms a direct link between virions and kinesin-1, yet in its absence VACV egress still occurs on microtubules. During a co-immunoprecipitation screen to seek an alternative link between virions and kinesin, A36 was found to bind isoform KLC1 rather than KLC2. The F12/E2 complex associates preferentially with the C-terminal tail of KLC2, to a region that overlaps the binding site of cellular 14-3-3 proteins. F12/E2 displaces 14-3-3 from KLC and, unlike 14-3-3, does not require phosphorylation of KLC for its binding. The region determining the KLC1 specificity of A36 was mapped to the KLC N-terminal heptad repeat region that is responsible for its association with kinesin heavy chain. Despite these differing binding properties F12/E2 can co-operatively enhance A36 association with KLC, particularly when using a KLC1-KLC2 chimaera that resembles several KLC1 spliceforms and can bind A36 and F12/E2 efficiently. This is the first example of a pathogen encoding multiple proteins that co-operatively associate with kinesin-1. © 2017 The Authors. Traffic published by John Wiley & Sons Ltd.

Quercetin as an Antiviral Agent Inhibits Influenza A Virus (IAV) Entry.

PubMed

Wu, Wenjiao; Li, Richan; Li, Xianglian; He, Jian; Jiang, Shibo; Liu, Shuwen; Yang, Jie

2015-12-25

Influenza A viruses (IAVs) cause seasonal pandemics and epidemics with high morbidity and mortality, which calls for effective anti-IAV agents. The glycoprotein hemagglutinin of influenza virus plays a crucial role in the initial stage of virus infection, making it a potential target for anti-influenza therapeutics development. Here we found that quercetin inhibited influenza infection with a wide spectrum of strains, including A/Puerto Rico/8/34 (H1N1), A/FM-1/47/1 (H1N1), and A/Aichi/2/68 (H3N2) with half maximal inhibitory concentration (IC50) of 7.756 ± 1.097, 6.225 ± 0.467, and 2.738 ± 1.931 μg/mL, respectively. Mechanism studies identified that quercetin showed interaction with the HA2 subunit. Moreover, quercetin could inhibit the entry of the H5N1 virus using the pseudovirus-based drug screening system. This study indicates that quercetin showing inhibitory activity in the early stage of influenza infection provides a future therapeutic option to develop effective, safe and affordable natural products for the treatment and prophylaxis of IAV infections.

Glycoprotein D actively induces rapid internalization of two nectin-1 isoforms during herpes simplex virus entry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stiles, Katie M., E-mail: stileskm@mail.med.upenn.ed; Krummenacher, Claude

2010-03-30

Entry of herpes simplex virus (HSV) occurs either by fusion at the plasma membrane or by endocytosis and fusion with an endosome. Binding of glycoprotein D (gD) to a receptor such as nectin-1 is essential in both cases. We show that virion gD triggered the rapid down-regulation of nectin-1 with kinetics similar to those of virus entry. In contrast, nectin-1 was not constitutively recycled from the surface of uninfected cells. Both the nectin-1alpha and beta isoforms were internalized in response to gD despite having different cytoplasmic tails. However, deletion of the nectin-1 cytoplasmic tail slowed down-regulation of nectin-1 and internalizationmore » of virions. These data suggest that nectin-1 interaction with a cytoplasmic protein is not required for its down-regulation. Overall, this study shows that gD binding actively induces the rapid internalization of various forms of nectin-1. We suggest that HSV activates a nectin-1 internalization pathway to use for endocytic entry.« less

Simian hemorrhagic fever virus cell entry is dependent on CD163 and uses a clathrin-mediated endocytosis-like pathway.

PubMed

Caì, Yíngyún; Postnikova, Elena N; Bernbaum, John G; Yú, Shu Qìng; Mazur, Steven; Deiuliis, Nicole M; Radoshitzky, Sheli R; Lackemeyer, Matthew G; McCluskey, Adam; Robinson, Phillip J; Haucke, Volker; Wahl-Jensen, Victoria; Bailey, Adam L; Lauck, Michael; Friedrich, Thomas C; O'Connor, David H; Goldberg, Tony L; Jahrling, Peter B; Kuhn, Jens H

2015-01-01

Simian hemorrhagic fever virus (SHFV) causes a severe and almost uniformly fatal viral hemorrhagic fever in Asian macaques but is thought to be nonpathogenic for humans. To date, the SHFV life cycle is almost completely uncharacterized on the molecular level. Here, we describe the first steps of the SHFV life cycle. Our experiments indicate that SHFV enters target cells by low-pH-dependent endocytosis. Dynamin inhibitors, chlorpromazine, methyl-β-cyclodextrin, chloroquine, and concanamycin A dramatically reduced SHFV entry efficiency, whereas the macropinocytosis inhibitors EIPA, blebbistatin, and wortmannin and the caveolin-mediated endocytosis inhibitors nystatin and filipin III had no effect. Furthermore, overexpression and knockout study and electron microscopy results indicate that SHFV entry occurs by a dynamin-dependent clathrin-mediated endocytosis-like pathway. Experiments utilizing latrunculin B, cytochalasin B, and cytochalasin D indicate that SHFV does not hijack the actin polymerization pathway. Treatment of target cells with proteases (proteinase K, papain, α-chymotrypsin, and trypsin) abrogated entry, indicating that the SHFV cell surface receptor is a protein. Phospholipases A2 and D had no effect on SHFV entry. Finally, treatment of cells with antibodies targeting CD163, a cell surface molecule identified as an entry factor for the SHFV-related porcine reproductive and respiratory syndrome virus, diminished SHFV replication, identifying CD163 as an important SHFV entry component. Simian hemorrhagic fever virus (SHFV) causes highly lethal disease in Asian macaques resembling human illness caused by Ebola or Lassa virus. However, little is known about SHFV's ecology and molecular biology and the mechanism by which it causes disease. The results of this study shed light on how SHFV enters its target cells. Using electron microscopy and inhibitors for various cellular pathways, we demonstrate that SHFV invades cells by low-pH-dependent, actin

Contributions of herpes simplex virus type 1 envelope proteins to entry by endocytosis

USDA-ARS?s Scientific Manuscript database

Herpes simplex virus (HSV) proteins specifically required for endocytic entry but not direct penetration have not been identified. HSVs deleted of gE, gG, gI, gJ, gM, UL45, or Us9 entered cells via either pH-dependent or pH-independent endocytosis and were inactivated by mildly acidic pH. Thus, the ...

Immunogenicity of HILDA/LIF either in a soluble or in a membrane anchored form expressed in vivo by recombinant vaccinia viruses.

PubMed

Taupin, J L; Acres, B; Dott, K; Schmitt, D; Kieny, M P; Gualde, N; Moreau, J F

1993-09-01

Insertion of various cDNAs in the genome of the vaccinia virus (VV) enables the in vivo and in vitro study of the functional role and/or the immunogenicity of the virally encoded recombinant proteins. We have prepared a recombinant VV expressing the cDNA of the human cytokine HILDA/LIF (human interleukin for DA cells/leukaemia inhibitory factor), and used this virus to immunize mice against this protein, which is very homologous to its murine counterpart (approximately 80% homology). We also constructed and expressed by the same system a chimeric gene encoding the HILDA/LIF protein fused to the 37 COOH-terminal amino-acids of the human decay accelerating factor (DAF). This sequence proved to be sufficient for the targeting of the fusion protein to the cell membrane, where it is linked to the phosphatidylinositols. Both recombinant VVs induced cytokine-specific antibodies in mice as analysed with an ELISA where the recombinant HILDA/LIF was plastic-coated and a cytofluorometric assay where the LIF-DAF molecule was present at the cell surface of stably transfected P815. In the latter case HILDA/LIF remained biologically active suggesting that it was expressed in its native form. The LIF-DAF fusion protein was found to exhibit a better capacity to elicit an antibody response against the native form of the cytokine as detected in cytofluorometric assays. Whatever the recombinant virus used to immunize the mice, the MoAbs obtained were positive either in the ELISA or in the cytofluorometric assays but one, which suggested that the plastic coating induced a conformational change of HILDA/LIF.

[Cell entry mechanisms of coronaviruses].

PubMed

Taguchi, Fumihiro; Matsuyama, Shutoku

2009-12-01

Enveloped viruses enter into cells via fusion of their envelope and cellular membrane. Spike (S) protein of coronavirus (CoV) is responsible for entry events. We studied the cell entry mechanisms of two different CoVs, murine coronavirus mouse hepatitis virus (MHV) and severe acute respiratory syndrome coronavirus (SARS-CoV). MHV-JHM that induces syncytia in infected cells entered directly from cell surface, i.e., fusion of envelope and plasma membrane, whereas SARS-CoV and MHV-2 that fail to induce syncytia entered via endosome in a protease-dependent fashion, i.e., fusion of envelope and endosomal membrane. The latter viruses entered directly from cell surface, when receptor-bound viruses were treated with proteases that activate fusion activity of their S proteins. The entry pathway of SARS-CoV could influence the severity of the disease. It was also reveled that a highly neurovirulent JHM spread in a receptor-independent fashion, which could result in a high neuropathogenicity of the virus.

Cyclosporin derivatives inhibit hepatitis B virus entry without interfering with NTCP transporter activity.

PubMed

Shimura, Satomi; Watashi, Koichi; Fukano, Kento; Peel, Michael; Sluder, Ann; Kawai, Fumihiro; Iwamoto, Masashi; Tsukuda, Senko; Takeuchi, Junko S; Miyake, Takeshi; Sugiyama, Masaya; Ogasawara, Yuki; Park, Sam-Yong; Tanaka, Yasuhito; Kusuhara, Hiroyuki; Mizokami, Masashi; Sureau, Camille; Wakita, Takaji

2017-04-01

The sodium taurocholate co-transporting polypeptide (NTCP) is the main target of most hepatitis B virus (HBV) specific entry inhibitors. Unfortunately, these agents also block NTCP transport of bile acids into hepatocytes, and thus have the potential to cause adverse effects. We aimed to identify small molecules that inhibit HBV entry while maintaining NTCP transporter function. We characterized a series of cyclosporine (CsA) derivatives for their anti-HBV activity and NTCP binding specificity using HepG2 cells overexpressing NTCP and primary human hepatocytes. The four most potent derivatives were tested for their capacity to prevent HBV entry, but maintain NTCP transporter function. Their antiviral activity against different HBV genotypes was analysed. We identified several CsA derivatives that inhibited HBV infection with a sub-micromolar IC 50 . Among them, SCY446 and SCY450 showed low activity against calcineurin (CN) and cyclophilins (CyPs), two major CsA cellular targets. This suggested that instead, these compounds interacted directly with NTCP to inhibit viral attachment to host cells, and have no immunosuppressive function. Importantly, we found that SCY450 and SCY995 did not impair the NTCP-dependent uptake of bile acids, and inhibited multiple HBV genotypes including a clinically relevant nucleoside analog-resistant HBV isolate. This is the first example of small molecule selective inhibition of HBV entry with no decrease in NTCP transporter activity. It suggests that the anti-HBV activity can be functionally separated from bile acid transport. These broadly active anti-HBV molecules are potential candidates for developing new drugs with fewer adverse effects. In this study, we identified new compounds that selectively inhibited hepatitis B virus (HBV) entry, and did not impair bile acid uptake. Our evidence offers a new strategy for developing anti-HBV drugs with fewer side effects. Copyright © 2016 European Association for the Study of the Liver

New frontiers in oncolytic viruses: optimizing and selecting for virus strains with improved efficacy

PubMed Central

2018-01-01

Oncolytic viruses have demonstrated selective replication and killing of tumor cells. Different types of oncolytic viruses – adenoviruses, alphaviruses, herpes simplex viruses, Newcastle disease viruses, rhabdoviruses, Coxsackie viruses, and vaccinia viruses – have been applied as either naturally occurring or engineered vectors. Numerous studies in animal-tumor models have demonstrated substantial tumor regression and prolonged survival rates. Moreover, clinical trials have confirmed good safety profiles and therapeutic efficacy for oncolytic viruses. Most encouragingly, the first cancer gene-therapy drug – Gendicine, based on oncolytic adenovirus type 5 – was approved in China. Likewise, a second-generation oncolytic herpes simplex virus-based drug for the treatment of melanoma has been registered in the US and Europe as talimogene laherparepvec. PMID:29445265

Infection cycles of large DNA viruses: Emerging themes and underlying questions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mutsafi, Yael, E-mail: yael.mutsafi@weizmann.ac.il; Fridmann-Sirkis, Yael; Milrot, Elad

The discovery of giant DNA viruses and the recent realization that such viruses are diverse and abundant blurred the distinction between viruses and cells. These findings elicited lively debates on the nature and origin of viruses as well as on their potential roles in the evolution of cells. The following essay is, however, concerned with new insights into fundamental structural and physical aspects of viral replication that were derived from studies conducted on large DNA viruses. Specifically, the entirely cytoplasmic replication cycles of Mimivirus and Vaccinia are discussed in light of the highly limited trafficking of large macromolecules in themore » crowded cytoplasm of cells. The extensive spatiotemporal order revealed by cytoplasmic viral factories is described and contended to play an important role in promoting the efficiency of these ‘nuclear-like’ organelles. Generation of single-layered internal membrane sheets in Mimivirus and Vaccinia, which proceeds through a novel membrane biogenesis mechanism that enables continuous supply of lipids, is highlighted as an intriguing case study of self-assembly. Mimivirus genome encapsidation was shown to occur through a portal different from the ‘stargate’ portal that is used for genome release. Such a ‘division of labor’ is proposed to enhance the efficacy of translocation processes of very large viral genomes. Finally, open questions concerning the infection cycles of giant viruses to which future studies are likely to provide novel and exciting answers are discussed. - Highlights: • The discovery of giant DNA viruses blurs the distinction between viruses and cells. • Mimivirus and Vaccinia replicate exclusively in their host cytoplasm. • Mimivirus genome is delivered through a unique portal coined the Stargate. • Generation of Mimivirus internal membrane proceeds through a novel pathway.« less

The Hemagglutinin of Bat-Associated Influenza Viruses Is Activated by TMPRSS2 for pH-Dependent Entry into Bat but Not Human Cells

PubMed Central

Hoffmann, Markus; Krüger, Nadine; Zmora, Pawel; Wrensch, Florian; Herrler, Georg; Pöhlmann, Stefan

2016-01-01

New World bats have recently been discovered to harbor influenza A virus (FLUAV)-related viruses, termed bat-associated influenza A-like viruses (batFLUAV). The internal proteins of batFLUAV are functional in mammalian cells. In contrast, no biological functionality could be demonstrated for the surface proteins, hemagglutinin (HA)-like (HAL) and neuraminidase (NA)-like (NAL), and these proteins need to be replaced by their human counterparts to allow spread of batFLUAV in human cells. Here, we employed rhabdoviral vectors to study the role of HAL and NAL in viral entry. Vectors pseudotyped with batFLUAV-HAL and -NAL were able to enter bat cells but not cells from other mammalian species. Host cell entry was mediated by HAL and was dependent on prior proteolytic activation of HAL and endosomal low pH. In contrast, sialic acids were dispensable for HAL-driven entry. Finally, the type II transmembrane serine protease TMPRSS2 was able to activate HAL for cell entry indicating that batFLUAV can utilize human proteases for HAL activation. Collectively, these results identify viral and cellular factors governing host cell entry driven by batFLUAV surface proteins. They suggest that the absence of a functional receptor precludes entry of batFLUAV into human cells while other prerequisites for entry, HAL activation and protonation, are met in target cells of human origin. PMID:27028521

Virus inactivation under the photodynamic effect of phthalocyanine zinc(II) complexes.

PubMed

Remichkova, Mimi; Mukova, Luchia; Nikolaeva-Glomb, Lubomira; Nikolova, Nadya; Doumanova, Lubka; Mantareva, Vanya; Angelov, Ivan; Kussovski, Veselin; Galabov, Angel S

2017-03-01

Various metal phthalocyanines have been studied for their capacity for photodynamic effects on viruses. Two newly synthesized water-soluble phthalocyanine Zn(II) complexes with different charges, cationic methylpyridyloxy-substituted Zn(II)- phthalocyanine (ZnPcMe) and anionic sulfophenoxy-substituted Zn(II)-phthalocyanine (ZnPcS), were used for photoinactivation of two DNA-containing enveloped viruses (herpes simplex virus type 1 and vaccinia virus), two RNA-containing enveloped viruses (bovine viral diarrhea virus and Newcastle disease virus) and two nude viruses (the enterovirus Coxsackie B1, a RNA-containing virus, and human adenovirus 5, a DNA virus). These two differently charged phthalocyanine complexes showed an identical marked virucidal effect against herpes simplex virus type 1, which was one and the same at an irradiation lasting 5 or 20 min (Δlog=3.0 and 4.0, respectively). Towards vaccinia virus this effect was lower, Δlog=1.8 under the effect of ZnPcMe and 2.0 for ZnPcS. Bovine viral diarrhea virus manifested a moderate sensitivity to ZnPcMe (Δlog=1.8) and a pronounced one to ZnPcS at 5- and 20-min irradiation (Δlog=5.8 and 5.3, respectively). The complexes were unable to inactivate Newcastle disease virus, Coxsackievirus B1 and human adenovirus type 5.

Vaccine and Wild-Type Strains of Yellow Fever Virus Engage Distinct Entry Mechanisms and Differentially Stimulate Antiviral Immune Responses

PubMed Central

Fernandez-Garcia, Maria Dolores; Meertens, Laurent; Chazal, Maxime; Hafirassou, Mohamed Lamine; Dejarnac, Ophélie; Zamborlini, Alessia; Despres, Philippe; Sauvonnet, Nathalie; Arenzana-Seisdedos, Fernando

2016-01-01

ABSTRACT The live attenuated yellow fever virus (YFV) vaccine 17D stands as a “gold standard” for a successful vaccine. 17D was developed empirically by passaging the wild-type Asibi strain in mouse and chicken embryo tissues. Despite its immense success, the molecular determinants for virulence attenuation and immunogenicity of the 17D vaccine are poorly understood. 17D evolved several mutations in its genome, most of which lie within the envelope (E) protein. Given the major role played by the YFV E protein during virus entry, it has been hypothesized that the residues that diverge between the Asibi and 17D E proteins may be key determinants of attenuation. In this study, we define the process of YFV entry into target cells and investigate its implication in the activation of the antiviral cytokine response. We found that Asibi infects host cells exclusively via the classical clathrin-mediated endocytosis, while 17D exploits a clathrin-independent pathway for infectious entry. We demonstrate that the mutations in the 17D E protein acquired during the attenuation process are sufficient to explain the differential entry of Asibi versus 17D. Interestingly, we show that 17D binds to and infects host cells more efficiently than Asibi, which culminates in increased delivery of viral RNA into the cytosol and robust activation of the cytokine-mediated antiviral response. Overall, our study reveals that 17D vaccine and Asibi enter target cells through distinct mechanisms and highlights a link between 17D attenuation, virus entry, and immune activation. PMID:26861019

Use of Bioclimatic Factors to Determine Potential Niche of Vaccinia Virus, an Emerging and Zoonotic Pathogen

NASA Astrophysics Data System (ADS)

Quiner, C. A.; Nakazawa, Y.

2017-12-01

Emerging and understudied pathogens often lack information that most commonly used analytical tools require, such as negative controls or baseline data making public health control of emerging pathogens challenging. In lieu of opportunities to collect more data from larger outbreaks or formal epidemiological studies, new analytical strategies, merging case data with publically available datasets, can be used to understand transmission patterns and drivers of disease emergence. Zoonotic infections with Vaccinia virus (VACV) were first reported in Brazil in 1999, VACV is an emerging zoonotic Orthopoxvirus, which primarily infects dairy cattle and farmers in close contact with infected cows. Prospective studies of emerging pathogens could provide critical data that would inform public health planning and response to outbreaks. By using the location of 87-recorded outbreaks and publicly available bioclimatic data we demonstrate one such approach. Using an Ecological Niche Model (ENM), we identify the environmental conditions under which VACV outbreaks have occurred, and determine additional locations in two affected South American countries that may be susceptible to transmission. Further, we show how suitability for the virus responds to different levels of various environmental factors and highlight the most important climatic factors in determining its transmission. The final ENM predicted all areas where Brazilian outbreaks occurred, two out of five Colombian outbreaks and identified new regions within Brazil that are suitable for transmission based on bioclimatic factors. Further, the most important factors in determining transmission suitability are precipitation of the wettest quarter, annual precipitation, mean temperature of the coldest quarter and mean diurnal range. The analyses here provide a means by which to study patterns of an emerging infectious disease, and regions that are potentially at risk for it, in spite of the paucity of critical data. Policy

Aryl-substituted aminobenzimidazoles targeting the hepatitis C virus internal ribosome entry site

PubMed Central

Ding, Kejia; Wang, Annie; Boerneke, Mark A.; Dibrov, Sergey M.; Hermann, Thomas

2014-01-01

We describe the exploration of N1-aryl-substituted benzimidazoles as ligands for the hepatitis C virus (HCV) internal ribosome entry site (IRES) RNA. The design of the compounds was guided by the co-crystal structure of a benzimidazole viral translation inhibitor in complex with the RNA target. Structure-binding activity relationships of aryl-substituted benzimidazole ligands were established that were consistent with the crystal structure of the translation inhibitor complex. PMID:24856063

Vaccine efficacy against malaria by the combination of porcine parvovirus-like particles and vaccinia virus vectors expressing CS of Plasmodium.

PubMed

Rodríguez, Dolores; González-Aseguinolaza, Gloria; Rodríguez, Juan R; Vijayan, Aneesh; Gherardi, Magdalena; Rueda, Paloma; Casal, J Ignacio; Esteban, Mariano

2012-01-01

With the aim to develop an efficient and cost-effective approach to control malaria, we have generated porcine parvovirus-like particles (PPV-VLPs) carrying the CD8(+) T cell epitope (SYVPSAEQI) of the circumsporozoite (CS) protein from Plasmodium yoelii fused to the PPV VP2 capsid protein (PPV-PYCS), and tested in prime/boost protocols with poxvirus vectors for efficacy in a rodent malaria model. As a proof-of concept, we have characterized the anti-CS CD8(+) T cell response elicited by these hybrid PPV-VLPs in BALB/c mice after immunizations with the protein PPV-PYCS administered alone or in combination with recombinant vaccinia virus (VACV) vectors from the Western Reserve (WR) and modified virus Ankara (MVA) strains expressing the entire P. yoelii CS protein. The results of different immunization protocols showed that the combination of PPV-PYCS prime/poxvirus boost was highly immunogenic, inducing specific CD8+ T cell responses to CS resulting in 95% reduction in liver stage parasites two days following sporozoite challenge. In contrast, neither the administration of PPV-PYCS alone nor the immunization with the vectors given in the order poxvirus/VLPs was as effective. The immune profile induced by VLPs/MVA boost was associated with polyfunctional and effector memory CD8+ T cell responses. These findings highlight the use of recombinant parvovirus PPV-PYCS particles as priming agents and poxvirus vectors, like MVA, as booster to enhance specific CD8+ T cell responses to Plasmodium antigens and to control infection. These observations are relevant in the design of T cell-inducing vaccines against malaria.

Subclinical bovine vaccinia: An important risk factor in the epidemiology of this zoonosis in cattle.

PubMed

Rehfeld, Izabelle Silva; Matos, Ana Carolina Diniz; Guedes, Maria Isabel Maldonado Coelho; Costa, Aristóteles Gomes; Fraiha, Ana Luiza Soares; Lobato, Zélia Inês Portela

2017-10-01

Bovine vaccinia (BV) is a zoonosis caused by Vaccinia virus (VACV) that mainly affects lactating cows and dairy farm milkers. The epidemiological role(s) of other cattle categories such as dry cows, bulls, and heifers in BV remains unclear. This study was performed to investigate VACV in affected dairy cattle herds and perifocal farms during an outbreak in Brazil. Crusts from lesions of cows' teats were collected from all farms with BV outbreaks. Milk, feces, blood, and serum were collected from symptomatic and asymptomatic lactating cows. Blood and serum were also sampled from other cattle categories (calves, heifers, dry cows, and bulls). The samples were tested for VACV by PCR, and to confirm VACV viability, VACV-positive samples were inoculated in BSC-40 cells and stained using immunoperoxidase. Neutralizing antibodies were investigated using plaque reduction neutralization test. Viral DNA was detected in milk, blood, and feces samples of symptomatic and asymptomatic dairy cows and in blood samples from other cattle categories on farms with and without confirmed BV outbreak. In affected farms, viable virus was identified in feces and milk samples from lactating cows and in blood samples from asymptomatic dry cows. Viable VACV was also identified in feces from lactating cows and one bull's blood sample from perifocal farms. Neutralizing antibodies were detected in 81.6% of the herds affected by BV and in 53.8% of the herds on perifocal farms. The presented data indicate a potential source of viral dissemination, which contributes to the persistence and spread of VACV in the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

A combination HIV reporter virus system for measuring post-entry event efficiency and viral outcome in primary CD4+ T cell subsets.

PubMed

Tilton, Carisa A; Tabler, Caroline O; Lucera, Mark B; Marek, Samantha L; Haqqani, Aiman A; Tilton, John C

2014-01-01

Fusion between the viral membrane of human immunodeficiency virus (HIV) and the host cell marks the end of the HIV entry process and the beginning of a series of post-entry events including uncoating, reverse transcription, integration, and viral gene expression. The efficiency of post-entry events can be modulated by cellular factors including viral restriction factors and can lead to several distinct outcomes: productive, latent, or abortive infection. Understanding host and viral proteins impacting post-entry event efficiency and viral outcome is critical for strategies to reduce HIV infectivity and to optimize transduction of HIV-based gene therapy vectors. Here, we report a combination reporter virus system measuring both membrane fusion and viral promoter-driven gene expression. This system enables precise determination of unstimulated primary CD4+ T cell subsets targeted by HIV, the efficiency of post-entry viral events, and viral outcome and is compatible with high-throughput screening and cell-sorting methods. Copyright © 2013 Elsevier B.V. All rights reserved.

Mucosal Immunization with Newcastle Disease Virus Vector Coexpressing HIV-1 Env and Gag Proteins Elicits Potent Serum, Mucosal, and Cellular Immune Responses That Protect against Vaccinia Virus Env and Gag Challenges

PubMed Central

Khattar, Sunil K.; Manoharan, Vinoth; Bhattarai, Bikash; LaBranche, Celia C.; Montefiori, David C.

2015-01-01

ABSTRACT Newcastle disease virus (NDV) avirulent strain LaSota was used to coexpress gp160 Env and p55 Gag from a single vector to enhance both Env-specific and Gag-specific immune responses. The optimal transcription position for both Env and Gag genes in the NDV genome was determined by generating recombinant NDV (rNDV)-Env-Gag (gp160 located between the P and M genes and Gag between the HN and L genes), rNDV-Gag-Env (Gag located between the P and M genes and gp160 between the HN and L genes), rNDV-Env/Gag (gp160 followed by Gag located between the P and M genes), and rNDV-Gag/Env (Gag followed by gp160 located between the P and M genes). All the recombinant viruses replicated at levels similar to those seen with parental NDV in embryonated chicken eggs and in chicken fibroblast cells. Both gp160 and Gag proteins were expressed at high levels in cell culture, with gp160 found to be incorporated into the envelope of NDV. The Gag and Env proteins expressed by all the recombinants except rNDV-Env-Gag self-assembled into human immunodeficiency virus type 1 (HIV-1) virus-like particles (VLPs). Immunization of guinea pigs by the intranasal route with these rNDVs produced long-lasting Env- and Gag-specific humoral immune responses. The Env-specific humoral and mucosal immune responses and Gag-specific humoral immune responses were higher in rNDV-Gag/Env and rNDV-Env/Gag than in the other recombinants. rNDV-Gag/Env and rNDV-Env/Gag were also more efficient in inducing cellular as well as protective immune responses to challenge with vaccinia viruses expressing HIV-1 Env and Gag in mice. These results suggest that vaccination with a single rNDV coexpressing Env and Gag represents a promising strategy to enhance immunogenicity and protective efficacy against HIV. PMID:26199332

THE LS-ANTIGEN OF VACCINIA

PubMed Central

Smadel, Joseph E.; Rivers, Thomas M.

1942-01-01

Experimental data are presented which may be interpreted as follows. The heat-labile (L) and heat-stable (S) antigens of vaccinia occur in nature as a complex consisting of a single substance with two serologically active parts, each of which may be degraded independently of the other. PMID:19871173

Vaccinia virus protein A3 is required for the production of normal immature virions and for the encapsidation of the nucleocapsid protein L4

PubMed Central

Jesus, Desyree Murta; Moussatche, Nissin; McFadden, Baron D.; Nielsen, Casey Paulasue; D’Costa, Susan M.; Condit, Richard C.

2015-01-01

Maturation of the vaccinia virion is an intricate process that results in the organization of the viroplasm contained in immature virions into the lateral bodies, core wall and nucleocapsid observed in the mature particles. It is unclear how this organization takes place and studies with mutants are indispensable in understanding this process. By characterizing an inducible mutant in the A3L gene, we revealed that A3, an inner core wall protein, is important for formation of normal immature viruses and also for the correct localization of L4, a nucleocapsid protein. L4 did not accumulate in the viral factories in the absence of A3 and was not encapsidated in the particles that do not contain A3. These data strengthen our previously suggested hypothesis that A3 and L4 interact and that this interaction is critical for proper formation of the core wall and nucleocapsid. PMID:25765002

Inhibition of herpes simplex virus type 1 entry by chloride channel inhibitors tamoxifen and NPPB

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Kai; College of Life Science and Technology, Jinan University, Guangzhou; Chen, Maoyun

2014-04-18

Highlights: • We analyze the anti-HSV potential of chloride channel inhibitors. • Tamoxifen and NPPB show anti-HSV-1 and anti-ACV-resistant HSV-1 activities. • HSV-1 infection induces intracellular chloride concentration increasing. • Tamoxifen and NPPB inhibit HSV-1 early infection. • Tamoxifen and NPPB prevent the fusion process of HSV-1. - Abstract: Herpes simplex virus type 1 (HSV-1) infection is very common worldwide and can cause significant health problems from periodic skin and corneal lesions to encephalitis. Appearance of drug-resistant viruses in clinical therapy has made exploring novel antiviral agents emergent. Here we show that chloride channel inhibitors, including tamoxifen and 5-nitro-2-(3-phenyl-propylamino) benzoicmore » acid (NPPB), exhibited extensive antiviral activities toward HSV-1 and ACV-resistant HSV viruses. HSV-1 infection induced chloride ion influx while treatment with inhibitors reduced the increase of intracellular chloride ion concentration. Pretreatment or treatment of inhibitors at different time points during HSV-1 infection all suppressed viral RNA synthesis, protein expression and virus production. More detailed studies demonstrated that tamoxifen and NPPB acted as potent inhibitors of HSV-1 early entry step by preventing viral binding, penetration and nuclear translocation. Specifically the compounds appeared to affect viral fusion process by inhibiting virus binding to lipid rafts and interrupting calcium homeostasis. Taken together, the observation that tamoxifen and NPPB can block viral entry suggests a stronger potential for these compounds as well as other ion channel inhibitors in antiviral therapy against HSV-1, especially the compound tamoxifen is an immediately actionable drug that can be reused for treatment of HSV-1 infections.« less

Vaccination with recombinant Modified Vaccinia Ankara (MVA) viruses expressing single African horse sickness virus VP2 antigens induced cross-reactive virus neutralising antibodies (VNAb) in horses when administered in combination.

PubMed

Manning, Nicola Mary; Bachanek-Bankowska, Katarzyna; Mertens, Peter Paul Clement; Castillo-Olivares, Javier

2017-10-20

African horse sickness is a lethal viral disease of equids transmitted by biting midges of the Genus Culicoides. The disease is endemic to sub-Saharan Africa but outbreaks of high mortality and economic impact have occurred in the past in non-endemic regions of Africa, Asia and Southern Europe. Vaccination is critical for the control of this disease but only live attenuated vaccines are currently available. However, there are bio-safety concerns over the use of this type of vaccines, especially in non-endemic countries, and live attenuated vaccines do not have DIVA (Differentiation of Infected from Vaccinated Animals) capacity. In addition, large scale manufacturing of live attenuated vaccines of AHSV represents a significant environmental and health risk and level 3 bio-safety containment facilities are required for their production. A variety of different technologies have been investigated over the years to develop alternative AHSV vaccines, including the use of viral vaccine vectors such Modified Vaccinia Ankara virus (MVA). In previous studies we demonstrated that recombinant MVA expressing outer capsid protein AHSV-VP2 induced virus neutralising antibodies and protection against virulent challenge both in a mouse model and in the horse. However, AHSV-VP2 is antigenically variable and determines the existence of 9 different AHSV serotypes. Immunity against AHSV is serotype-specific and there is limited cross-reactivity between certain AHSV serotypes: 1 and 2, 3 and 7, 5 and 8, 6 and 9. In Africa, multiple serotypes circulate simultaneously and a polyvalent attenuated vaccine comprising different AHSV serotypes is used. We investigated the potential of a polyvalent AHSV vaccination strategy based on combinations of MVA-VP2 viruses each expressing a single VP2 antigen from a specific serotype. We showed that administration of 2 different recombinant MVA viruses, each expressing a single VP2 protein from AHSV serotype 4 or 9, denoted respectively as MVA-VP2

Recombinant Vaccinia Viruses Coding Transgenes of Apoptosis-Inducing Proteins Enhance Apoptosis But Not Immunogenicity of Infected Tumor Cells

PubMed Central

Tkachenko, Anastasiya; Richter, Vladimir

2017-01-01

Genetic modifications of the oncolytic vaccinia virus (VV) improve selective tumor cell infection and death, as well as activation of antitumor immunity. We have engineered a double recombinant VV, coding human GM-CSF, and apoptosis-inducing protein apoptin (VV-GMCSF-Apo) for comparing with the earlier constructed double recombinant VV-GMCSF-Lact, coding another apoptosis-inducing protein, lactaptin, which activated different cell death pathways than apoptin. We showed that both these recombinant VVs more considerably activated a set of critical apoptosis markers in infected cells than the recombinant VV coding GM-CSF alone (VV-GMCSF-dGF): these were phosphatidylserine externalization, caspase-3 and caspase-7 activation, DNA fragmentation, and upregulation of proapoptotic protein BAX. However, only VV-GMCSF-Lact efficiently decreased the mitochondrial membrane potential of infected cancer cells. Investigating immunogenic cell death markers in cancer cells infected with recombinant VVs, we demonstrated that all tested recombinant VVs were efficient in calreticulin and HSP70 externalization, decrease of cellular HMGB1, and ATP secretion. The comparison of antitumor activity against advanced MDA-MB-231 tumor revealed that both recombinants VV-GMCSF-Lact and VV-GMCSF-Apo efficiently delay tumor growth. Our results demonstrate that the composition of GM-CSF and apoptosis-inducing proteins in the VV genome is very efficient tool for specific killing of cancer cells and for activation of antitumor immunity. PMID:28951871

Dissection of the Influenza A Virus Endocytic Routes Reveals Macropinocytosis as an Alternative Entry Pathway

PubMed Central

de Vries, Erik; Tscherne, Donna M.; Wienholts, Marleen J.; Cobos-Jiménez, Viviana; Scholte, Florine; García-Sastre, Adolfo; Rottier, Peter J. M.; de Haan, Cornelis A. M.

2011-01-01

Influenza A virus (IAV) enters host cells upon binding of its hemagglutinin glycoprotein to sialylated host cell receptors. Whereas dynamin-dependent, clathrin-mediated endocytosis (CME) is generally considered as the IAV infection pathway, some observations suggest the occurrence of an as yet uncharacterized alternative entry route. By manipulating entry parameters we established experimental conditions that allow the separate analysis of dynamin-dependent and -independent entry of IAV. Whereas entry of IAV in phosphate-buffered saline could be completely inhibited by dynasore, a specific inhibitor of dynamin, a dynasore-insensitive entry pathway became functional in the presence of fetal calf serum. This finding was confirmed with the use of small interfering RNAs targeting dynamin-2. In the presence of serum, both IAV entry pathways were operational. Under these conditions entry could be fully blocked by combined treatment with dynasore and the amiloride derivative EIPA, the hallmark inhibitor of macropinocytosis, whereas either drug alone had no effect. The sensitivity of the dynamin-independent entry pathway to inhibitors or dominant-negative mutants affecting actomyosin dynamics as well as to a number of specific inhibitors of growth factor receptor tyrosine kinases and downstream effectors thereof all point to the involvement of macropinocytosis in IAV entry. Consistently, IAV particles and soluble FITC-dextran were shown to co-localize in cells in the same vesicles. Thus, in addition to the classical dynamin-dependent, clathrin-mediated endocytosis pathway, IAV enters host cells by a dynamin-independent route that has all the characteristics of macropinocytosis. PMID:21483486

Epidermal Growth Factor Receptor-PI3K Signaling Controls Cofilin Activity To Facilitate Herpes Simplex Virus 1 Entry into Neuronal Cells

PubMed Central

Zheng, Kai; Xiang, Yangfei; Wang, Xiao; Wang, Qiaoli; Zhong, Meigong; Wang, Shaoxiang; Wang, Xiaoyan; Fan, Jianglin; Kitazato, Kaio; Wang, Yifei

2014-01-01

ABSTRACT Herpes simplex virus type 1 (HSV-1) establishes latency in neurons and can cause severe disseminated infection with neurological impairment and high mortality. This neurodegeneration is thought to be tightly associated with virus-induced cytoskeleton disruption. Currently, the regulation pattern of the actin cytoskeleton and the involved molecular mechanisms during HSV-1 entry into neurons remain unclear. Here, we demonstrate that the entry of HSV-1 into neuronal cells induces biphasic remodeling of the actin cytoskeleton and an initial inactivation followed by the subsequent activation of cofilin, a member of the actin depolymerizing factor family that is critical for actin reorganization. The disruption of F-actin dynamics or the modulation of cofilin activity by mutation, knockdown, or overexpression affects HSV-1 entry efficacy and virus-mediated cell ruffle formation. Binding of the HSV-1 envelope initiates the epidermal growth factor receptor (EGFR)-phosphatidylinositide 3-kinase (PI3K) signaling pathway, which leads to virus-induced early cofilin phosphorylation and F-actin polymerization. Moreover, the extracellular signal-regulated kinase (ERK) kinase and Rho-associated, coiled-coil-containing protein kinase 1 (ROCK) are recruited as downstream mediators of the HSV-1-induced cofilin inactivation pathway. Inhibitors specific for those kinases significantly reduce the virus infectivity without affecting virus binding to the target cells. Additionally, lipid rafts are clustered to promote EGFR-associated signaling cascade transduction. We propose that HSV-1 hijacks cofilin to initiate infection. These results could promote a better understanding of the pathogenesis of HSV-1-induced neurological diseases. PMID:24425731

Recombinant sheep pox virus proteins elicit neutralizing antibodies

USDA-ARS?s Scientific Manuscript database

The aim of this study was to evaluate the immunogenicity and neutralizing activity of bacterially-expressed sheep pox virus (SPPV) structural proteins as candidate subunit vaccines to control sheep pox disease. SPPV structural proteins were identified by sequence homology with proteins from vaccinia...

Specificity and 6-Month Durability of Immune Responses Induced by DNA and Recombinant Modified Vaccinia Ankara Vaccines Expressing HIV-1 Virus-Like Particles

PubMed Central

Goepfert, Paul A.; Elizaga, Marnie L.; Seaton, Kelly; Tomaras, Georgia D.; Montefiori, David C.; Sato, Alicia; Hural, John; DeRosa, Stephen C.; Kalams, Spyros A.; McElrath, M. Juliana; Keefer, Michael C.; Baden, Lindsey R.; Lama, Javier R.; Sanchez, Jorge; Mulligan, Mark J.; Buchbinder, Susan P.; Hammer, Scott M.; Koblin, Beryl A.; Pensiero, Michael; Butler, Chris; Moss, Bernard; Robinson, Harriet L.; Donastorg, Yeycy; Qin, Li; Lawrence, Dale; Cardinali, Massimo; Bae, Jin; Holt, Renée; Redinger, Huguette; Johannessen, Jan; Broder, Gail; Moody-White, Jerri; McKay, Butch; Calazans, Gabriela; Bentley, Carter; Kakinami, Lisa; Skibinski, Katie; Estep, Scharla; Tseng, Jenny; Swenson, Molly; Madenwald, Tamra; Overton, Edgar Turner; Edupuganti, Srilatha; Rouphael, Nadine; Whitaker, Jennifer; Hay, C Mhorag; Bunce, Catherine A; Gonzales, Pedro; Hurtado, Juan Carlos; Dolin, Raphael; Mayer, Ken; Walsh, Steven; Johnson, Jennifer

2014-01-01

Background. Clade B DNA and recombinant modified vaccinia Ankara (MVA) vaccines producing virus-like particles displaying trimeric membrane-bound envelope glycoprotein (Env) were tested in a phase 2a trial in human immunodeficiency virus (HIV)–uninfected adults for safety, immunogenicity, and 6-month durability of immune responses. Methods. A total of 299 individuals received 2 doses of JS7 DNA vaccine and 2 doses of MVA/HIV62B at 0, 2, 4, and 6 months, respectively (the DDMM regimen); 3 doses of MVA/HIV62B at 0, 2, and 6 months (the MMM regimen); or placebo injections. Results. At peak response, 93.2% of the DDMM group and 98.4% of the MMM group had binding antibodies for Env. These binding antibodies were more frequent and of higher magnitude for the transmembrane subunit (gp41) than the receptor-binding subunit (gp120) of Env. For both regimens, response rates were higher for CD4+ T cells (66.4% in the DDMM group and 43.1% in the MMM group) than for CD8+ T cells (21.8% in the DDMM group and 14.9% in the MMM group). Responding CD4+ and CD8+ T cells were biased toward Gag, and >70% produced 2 or 3 of the 4 cytokines evaluated (ie, interferon γ, interleukin 2, tumor necrosis factor α, and granzyme B). Six months after vaccination, the magnitudes of antibodies and T-cell responses had decreased by <3-fold. Conclusions. DDMM and MMM vaccinations with virus-like particle–expressing immunogens elicited durable antibody and T-cell responses. PMID:24403557