Sample records for challenge virus replication
-
Ongvarrasopone, Chalermporn; Chomchay, Ekapol; Panyim, Sakol
2010-10-01
PmRab7 is a Penaeus monodon small GTPase protein possibly involved in replication of several shrimp viruses. In this study RNA interference (RNAi) using double-stranded RNA (dsRNA) targeting PmRab7 gene (dsRNA-PmRab7) was employed to silence the expression of PmRab7 to investigate the inhibitory effect on Laem-Singh virus (LSNV) replication. Injection of dsRNA-PmRab7 24h before challenge with the virus resulted in a drastic decrease of PmRab7 mRNA and complete inhibition of LSNV replication at 3 days post-challenge. In a therapeutic mode, shrimp injected with dsRNA-PmRab7 1 day but not at 3 or 5 days post-LSNV challenge resulted in inhibition of LSNV replication. These results pave the way to use dsRNA-PmRab7 to prevent or cure LSNV infection in shrimp. Copyright © 2010 Elsevier B.V. All rights reserved.
-
Nuclear proteins hijacked by mammalian cytoplasmic plus strand RNA viruses
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lloyd, Richard E., E-mail: rlloyd@bcm.edu
Plus strand RNA viruses that replicate in the cytoplasm face challenges in supporting the numerous biosynthetic functions required for replication and propagation. Most of these viruses are genetically simple and rely heavily on co-opting cellular proteins, particularly cellular RNA-binding proteins, into new roles for support of virus infection at the level of virus-specific translation, and building RNA replication complexes. In the course of infectious cycles many nuclear-cytoplasmic shuttling proteins of mostly nuclear distribution are detained in the cytoplasm by viruses and re-purposed for their own gain. Many mammalian viruses hijack a common group of the same factors. This review summarizesmore » recent gains in our knowledge of how cytoplasmic RNA viruses use these co-opted host nuclear factors in new functional roles supporting virus translation and virus RNA replication and common themes employed between different virus groups. - Highlights: • Nuclear shuttling host proteins are commonly hijacked by RNA viruses to support replication. • A limited group of ubiquitous RNA binding proteins are commonly hijacked by a broad range of viruses. • Key virus proteins alter roles of RNA binding proteins in different stages of virus replication.« less
-
Nuclear Proteins Hijacked by Mammalian Cytoplasmic Plus Strand RNA Viruses
Lloyd, Richard E.
2015-01-01
Plus strand RNA viruses that replicate in the cytoplasm face challenges in supporting the numerous biosynthetic functions required for replication and propagation. Most of these viruses are genetically simple and rely heavily on co-opting cellular proteins, particularly cellular RNA-binding proteins, into new roles for support of virus infection at the level of virus-specific translation, and building RNA replication complexes. In the course of infectious cycles many nuclear-cytoplasmic shuttling proteins of mostly nuclear distribution are detained in the cytoplasm by viruses and re-purposed for their own gain. Many mammalian viruses hijack a common group of the same factors. This review summarizes recent gains in our knowledge of how cytoplasmic RNA viruses use these co-opted host nuclear factors in new functional roles supporting virus translation and virus RNA replication and common themes employed between different virus groups. PMID:25818028
-
Ham, Claire; Ferguson, Deborah; Tudor, Hannah; Mattiuzzo, Giada; Klaver, Bep; Page, Mark; Stebbings, Richard; Das, Atze T.; Berkhout, Ben; Almond, Neil; Cranage, Martin P.
2016-01-01
In order to evaluate the role of persisting virus replication during occult phase immunisation in the live attenuated SIV vaccine model, a novel SIVmac239Δnef variant (SIVrtTA) genetically engineered to replicate in the presence of doxycycline was evaluated for its ability to protect against wild-type SIVmac239. Indian rhesus macaques were vaccinated either with SIVrtTA or with SIVmac239Δnef. Doxycycline was withdrawn from 4 of 8 SIVrtTA vaccinates before challenge with wild-type virus. Unvaccinated challenge controls exhibited ~107 peak plasma viral RNA copies/ml persisting beyond the acute phase. Six vaccinates, four SIVmac239Δnef and two SIVrtTA vaccinates exhibited complete protection, defined by lack of wild-type viraemia post-challenge and virus-specific PCR analysis of tissues recovered post-mortem, whereas six SIVrtTA vaccinates were protected from high levels of viraemia. Critically, the complete protection in two SIVrtTA vaccinates was associated with enhanced SIVrtTA replication in the immediate post-acute vaccination period but was independent of doxycycline status at the time of challenge. Mutations were identified in the LTR promoter region and rtTA gene that do not affect doxycycline-control but were associated with enhanced post-acute phase replication in protected vaccinates. High frequencies of total circulating CD8+T effector memory cells and a higher total frequency of SIV-specific CD8+ mono and polyfunctional T cells on the day of wild-type challenge were associated with complete protection but these parameters were not predictive of outcome when assessed 130 days after challenge. Moreover, challenge virus-specific Nef CD8+ polyfunctional T cell responses and antigen were detected in tissues post mortem in completely-protected macaques indicating post-challenge control of infection. Within the parameters of the study design, on-going occult-phase replication may not be absolutely required for protective immunity. PMID:28002473
-
Correlation between Marek's disease virus pathotype and replication.
Dunn, John R; Auten, Kiva; Heidari, Mohammad; Buscaglia, Celina
2014-06-01
Marek's disease (MD) virus (MDV) is an alphaherpesvirus that causes MD, a lymphoproliferative disease in chickens. Pathotyping has become an increasingly important assay for monitoring shifts in virulence of field strains; however, it is time-consuming and expensive, and alternatives are needed to provide fast answers in the face of current outbreaks. The purpose of this study was to determine whether differences in virus replication between pathotypes that have been reported using a small number of virulent (v) and very virulent plus (vv+) MDV strains could be confirmed with a large collection of MD viruses. Based on pilot study data, bursa, brain, and lung samples were collected at 9 and 11 days postinoculation (dpi) from birds challenged with 1 of 15 MDV strains. The correlation between virus replication and virulence was confirmed between vMDV strains and higher virulent strains, but in most cases, there was no significant difference between very virulent (vv) and vv+MDV groups. At both 9 and 11 dpi, chickens infected with vv and vv+MDV had significantly lower body weights and relative thymus and bursa weights compared with chickens challenged with vMDV. However, similar to virus quantity, there was no significant difference between weights in birds challenged with vv or vv+MDV. The significant differences observed in maternal antibody negative (ab-) chickens were not significant in maternal antibody positive (ab+) chickens, demonstrating the requirement of ab- birds for this type of comparison. These data do not support the use of virus replication or organ weights as an alternative to pathotyping for discrimination between all three virulent MDV pathotypes but may be useful for determining a virus replication threshold to choose which field strains meet a minimum virulence to be pathotyped by traditional methods.
-
Goatley, Lynnette C.; Jabbar, Tamara; Sanchez-Cordon, Pedro J.; Netherton, Christopher L.; Chapman, David A. G.; Dixon, Linda K.
2017-01-01
ABSTRACT Many of the approximately 165 proteins encoded by the African swine fever virus (ASFV) genome do not have significant similarity to known proteins and have not been studied experimentally. One such protein is DP148R. We showed that the DP148R gene is transcribed at early times postinfection. Deletion of this gene did not reduce virus replication in macrophages, showing that it is not essential for replication in these cells. However, deletion of this gene from a virulent isolate, Benin 97/1, producing the BeninΔDP148R virus, dramatically reduced the virulence of the virus in vivo. All pigs infected with the BeninΔDP148R virus survived infection, showing only transient mild clinical signs soon after immunization. Following challenge with the parental virulent virus, all pigs immunized by the intramuscular route (11/11) and all except one immunized by the intranasal route (5/6) survived. Mild or no clinical signs were observed after challenge. As expected, control nonimmune pigs developed signs of acute African swine fever (ASF). The virus genome and infectious virus were observed soon after immunization, coincident with the onset of clinical signs (∼106 genome copies or 50% tissue culture infective doses/ml). The levels of the virus genome declined over an extended period up to 60 days postimmunization. In contrast, infectious virus was no longer detectable by days 30 to 35. Gamma interferon (IFN-γ) was detected in serum between days 4 and 7 postimmunization, and IFN-γ-producing cells were detected in all pigs analyzed following stimulation of immune lymphocytes with whole virus. ASFV-specific antibodies were first detected from day 10 postimmunization. IMPORTANCE African swine fever (ASF) is endemic in Africa, parts of the Trans Caucasus, the Russian Federation, and several European countries. The lack of a vaccine hinders control. Many of the ASF virus genes lack similarity to known genes and have not been characterized. We have shown that one of these, DP148R, is transcribed early during virus replication in cells and can be deleted from the virus genome without reducing virus replication. The virus with the gene deletion, BeninΔDP148R, caused mild clinical signs in pigs and induced high levels of protection against challenge with the parental virulent virus. Therefore, deletion of this gene can provide a target for the rational development of vaccines. PMID:28978700
-
Reis, Ana L; Goatley, Lynnette C; Jabbar, Tamara; Sanchez-Cordon, Pedro J; Netherton, Christopher L; Chapman, David A G; Dixon, Linda K
2017-12-15
Many of the approximately 165 proteins encoded by the African swine fever virus (ASFV) genome do not have significant similarity to known proteins and have not been studied experimentally. One such protein is DP148R. We showed that the DP148R gene is transcribed at early times postinfection. Deletion of this gene did not reduce virus replication in macrophages, showing that it is not essential for replication in these cells. However, deletion of this gene from a virulent isolate, Benin 97/1, producing the BeninΔDP148R virus, dramatically reduced the virulence of the virus in vivo All pigs infected with the BeninΔDP148R virus survived infection, showing only transient mild clinical signs soon after immunization. Following challenge with the parental virulent virus, all pigs immunized by the intramuscular route (11/11) and all except one immunized by the intranasal route (5/6) survived. Mild or no clinical signs were observed after challenge. As expected, control nonimmune pigs developed signs of acute African swine fever (ASF). The virus genome and infectious virus were observed soon after immunization, coincident with the onset of clinical signs (∼10 6 genome copies or 50% tissue culture infective doses/ml). The levels of the virus genome declined over an extended period up to 60 days postimmunization. In contrast, infectious virus was no longer detectable by days 30 to 35. Gamma interferon (IFN-γ) was detected in serum between days 4 and 7 postimmunization, and IFN-γ-producing cells were detected in all pigs analyzed following stimulation of immune lymphocytes with whole virus. ASFV-specific antibodies were first detected from day 10 postimmunization. IMPORTANCE African swine fever (ASF) is endemic in Africa, parts of the Trans Caucasus, the Russian Federation, and several European countries. The lack of a vaccine hinders control. Many of the ASF virus genes lack similarity to known genes and have not been characterized. We have shown that one of these, DP148R, is transcribed early during virus replication in cells and can be deleted from the virus genome without reducing virus replication. The virus with the gene deletion, BeninΔDP148R, caused mild clinical signs in pigs and induced high levels of protection against challenge with the parental virulent virus. Therefore, deletion of this gene can provide a target for the rational development of vaccines. Copyright © 2017 Reis et al.
-
Lo, Michael K; Bird, Brian H; Chattopadhyay, Anasuya; Drew, Clifton P; Martin, Brock E; Coleman, Joann D; Rose, John K; Nichol, Stuart T; Spiropoulou, Christina F
2014-01-01
Nipah virus (NiV) continues to cause outbreaks of fatal human encephalitis due to spillover from its bat reservoir. We determined that a single dose of replication-defective vesicular stomatitis virus (VSV)-based vaccine vectors expressing either the NiV fusion (F) or attachment (G) glycoproteins protected hamsters from over 1000 times LD50 NiV challenge. This highly effective single-dose protection coupled with an enhanced safety profile makes these candidates ideal for potential use in livestock and humans. Published by Elsevier B.V.
-
Purcell, M.K.; Garver, K.A.; Conway, C.; Elliott, D.G.; Kurath, G.
2009-01-01
Characterization of infectious haematopoietic necrosis virus (IHNV) field isolates from North America has established three main genogroups (U, M and L) that differ in host-specific virulence. In sockeye salmon, Oncorhynchus nerka, the U genogroup is highly virulent, whereas the M genogroup is nearly non-pathogenic. In this study, we sought to characterize the virus-host dynamics that contribute to genogroup-specific virulence in a captive stock of sockeye salmon from Redfish Lake in Idaho. Juvenile sockeye salmon were challenged by immersion and injection with either a representative U or M viral strain and sampled periodically until 14 days post-infection (p.i.). Fish challenged with each strain had positive viral titre by day 3, regardless of challenge route, but the fish exposed to the M genogroup virus had significantly lower virus titres than fish exposed to the U genogroup virus. Gene expression analysis by quantitative reverse transcriptase PCR was used to simultaneously assess viral load and host interferon (IFN) response in the anterior kidney. Viral load was significantly higher in the U-challenged fish relative to M-challenged fish. Both viruses induced expression of the IFN-stimulated genes (ISGs), but expression was usually significantly lower in the M-challenged group, particularly at later time points (7 and 14 days p.i.). However, ISG expression was comparable with 3 days post-immersion challenge despite a significant difference in viral load. Our data indicated that the M genogroup virus entered the host, replicated and spread in the sockeye salmon tissues, but to a lesser extent than the U genogroup. Both virus types induced a host IFN response, but the high virulence strain (U) continued to replicate in the presence of this response, whereas the low virulence strain (M) was cleared below detectable levels. We hypothesize that high virulence is associated with early in vivo replication allowing the virus to achieve a threshold level, which the host innate immune system cannot control. ?? 2009 Blackwell Publishing Ltd.
-
Purcell, M K; Garver, K A; Conway, C; Elliott, D G; Kurath, G
2009-07-01
Characterization of infectious haematopoietic necrosis virus (IHNV) field isolates from North America has established three main genogroups (U, M and L) that differ in host-specific virulence. In sockeye salmon, Oncorhynchus nerka, the U genogroup is highly virulent, whereas the M genogroup is nearly non-pathogenic. In this study, we sought to characterize the virus-host dynamics that contribute to genogroup-specific virulence in a captive stock of sockeye salmon from Redfish Lake in Idaho. Juvenile sockeye salmon were challenged by immersion and injection with either a representative U or M viral strain and sampled periodically until 14 days post-infection (p.i.). Fish challenged with each strain had positive viral titre by day 3, regardless of challenge route, but the fish exposed to the M genogroup virus had significantly lower virus titres than fish exposed to the U genogroup virus. Gene expression analysis by quantitative reverse transcriptase PCR was used to simultaneously assess viral load and host interferon (IFN) response in the anterior kidney. Viral load was significantly higher in the U-challenged fish relative to M-challenged fish. Both viruses induced expression of the IFN-stimulated genes (ISGs), but expression was usually significantly lower in the M-challenged group, particularly at later time points (7 and 14 days p.i.). However, ISG expression was comparable with 3 days post-immersion challenge despite a significant difference in viral load. Our data indicated that the M genogroup virus entered the host, replicated and spread in the sockeye salmon tissues, but to a lesser extent than the U genogroup. Both virus types induced a host IFN response, but the high virulence strain (U) continued to replicate in the presence of this response, whereas the low virulence strain (M) was cleared below detectable levels. We hypothesize that high virulence is associated with early in vivo replication allowing the virus to achieve a threshold level, which the host innate immune system cannot control.
-
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chen, Grace L., E-mail: chengra@niaid.nih.go; Lamirande, Elaine W., E-mail: elamirande@niaid.nih.go; Jin Hong, E-mail: jinh@medimmune.co
We studied the attenuation, immunogenicity and efficacy of the cold-adapted A/Ann Arbor/6/60 (AA ca) (H2N2) virus in mice and ferrets to evaluate its use in the event of an H2 influenza pandemic. The AA ca virus was restricted in replication in the respiratory tract of mice and ferrets. In mice, 2 doses of vaccine elicited a > 4-fold rise in hemagglutination-inhibition (HAI) titer and resulted in complete inhibition of viral replication following lethal homologous wild-type virus challenge. In ferrets, a single dose of the vaccine elicited a > 4-fold rise in HAI titer and conferred complete protection against homologous wild-typemore » virus challenge in the upper respiratory tract. In both mice and ferrets, the AA ca virus provided significant protection from challenge with heterologous H2 virus challenge in the respiratory tract. The AA ca vaccine is safe, immunogenic, and efficacious against homologous and heterologous challenge in mice and ferrets, supporting the evaluation of this vaccine in clinical trials.« less
-
Matsuoka, Yumiko; Suguitan, Amorsolo; Orandle, Marlene; Paskel, Myeisha; Boonnak, Kobporn; Gardner, Donald J.; Feldmann, Friederike; Feldmann, Heinz; Marino, Michael; Jin, Hong; Kemble, George
2014-01-01
ABSTRACT Live attenuated cold-adapted (ca) H5N1, H7N3, H6N1, and H9N2 influenza vaccine viruses replicated in the respiratory tract of mice and ferrets, and 2 doses of vaccines were immunogenic and protected these animals from challenge infection with homologous and heterologous wild-type (wt) viruses of the corresponding subtypes. However, when these vaccine candidates were evaluated in phase I clinical trials, there were inconsistencies between the observations in animal models and in humans. The vaccine viruses did not replicate well and immune responses were variable in humans, even though the study subjects were seronegative with respect to the vaccine viruses before vaccination. Therefore, we sought a model that would better reflect the findings in humans and evaluated African green monkeys (AGMs) as a nonhuman primate model. The distribution of sialic acid (SA) receptors in the respiratory tract of AGMs was similar to that in humans. We evaluated the replication of wt and ca viruses of avian influenza (AI) virus subtypes H5N1, H6N1, H7N3, and H9N2 in the respiratory tract of AGMs. All of the wt viruses replicated efficiently, while replication of the ca vaccine viruses was restricted to the upper respiratory tract. Interestingly, the patterns and sites of virus replication differed among the different subtypes. We also evaluated the immunogenicity and protective efficacy of H5N1, H6N1, H7N3, and H9N2 ca vaccines. Protection from wt virus challenge correlated well with the level of serum neutralizing antibodies. Immune responses were slightly better when vaccine was delivered by both intranasal and intratracheal delivery than when it was delivered intranasally by sprayer. We conclude that live attenuated pandemic influenza virus vaccines replicate similarly in AGMs and human subjects and that AGMs may be a useful model to evaluate the replication of ca vaccine candidates. IMPORTANCE Ferrets and mice are commonly used for preclinical evaluation of influenza vaccines. However, we observed significant inconsistencies between observations in humans and in these animal models. We used African green monkeys (AGMs) as a nonhuman primate (NHP) model for a comprehensive and comparative evaluation of pairs of wild-type and pandemic live attenuated influenza virus vaccines (pLAIV) representing four subtypes of avian influenza viruses and found that pLAIVs replicate similarly in AGMs and humans and that AGMs can be useful for evaluation of the protective efficacy of pLAIV. PMID:24807726
-
Ui, Hiroki; Yamayoshi, Seiya; Uraki, Ryuta; Kiso, Maki; Oishi, Kohei; Murakami, Shin; Mimori, Shigetaka; Kawaoka, Yoshihiro
2017-04-04
Vaccination is the first line of protection against influenza virus infection in humans. Although inactivated and live-attenuated vaccines are available, each vaccine has drawbacks in terms of immunogenicity and safety. To overcome these issues, our group has developed a replication-incompetent PB2-knockout (PB2-KO) influenza virus that replicates only in PB2-expressing cells. Here we generated PB2-KO viruses possessing the hemagglutinin (HA) and neuraminidase (NA) segments from H1N1pdm09 or type B viruses and tested their vaccine potential. The two PB2-KO viruses propagated efficiently in PB2-expressing cells, and expressed chimeric HA as expected. Virus-specific IgG and IgA antibodies were detected in mice immunized with the viruses, and the immunized mice showed milder clinical signs and/or lower virus replication levels in the respiratory tract upon virus challenge. Our results indicate that these PB2-KO viruses have potential as vaccine candidates. Copyright © 2017 Elsevier Ltd. All rights reserved.
-
Long-term protection against SHIV89.6P replication in HIV-1 Tat vaccinated cynomolgus monkeys.
Maggiorella, Maria Teresa; Baroncelli, Silvia; Michelini, Zuleika; Fanales-Belasio, Emanuele; Moretti, Sonia; Sernicola, Leonardo; Cara, Andrea; Negri, Donatella R M; Buttò, Stefano; Fiorelli, Valeria; Tripiciano, Antonella; Scoglio, Arianna; Caputo, Antonella; Borsetti, Alessandra; Ridolfi, Barbara; Bona, Roberta; ten Haaft, Peter; Macchia, Iole; Leone, Pasqualina; Pavone-Cossut, Maria Rosaria; Nappi, Filomena; Ciccozzi, Massimo; Heeney, Jonathan; Titti, Fausto; Cafaro, Aurelio; Ensoli, Barbara
2004-09-03
Vaccination with a biologically active Tat protein or tat DNA contained infection with the highly pathogenic SHIV89.6P virus, preventing CD4 T-cell decline and disease onset. Here we show that protection was prolonged, since neither CD4 T-cell decline nor active virus replication was observed in all vaccinated animals that controlled virus replication up to week 104 after the challenge. In contrast, virus persisted and replicated in peripheral blood mononuclear cells and lymph nodes of infected animals, two of which died. Tat-specific antibody, CD4 and CD8 T-cell responses were high and stable only in the animals controlling the infection. In contrast, Gag-specific antibody production and CD4 and CD8 T-cell responses were consistently and persistently positive only in the monkeys that did not control primary virus replication. These results indicate that vaccination with Tat protein or DNA induced long-term memory Tat-specific immune responses and controlled primary infection at its early stages allowing a long-term containment of virus replication and spread in blood and tissues.
-
Involvement of rainbow trout leucocytes in the pathogenesis of infectious hematopoietic necrosis
Chilmonczyk, S.; Winton, J.R.
1994-01-01
Rainbow trout Oncorhynchus myluss leucocytes were tested for their ability to support replication of infectious hematopoietic necrosis virus (IHNV). Viral replication occurred in vitro uslng leucocytes cultured from peripheral blood, kidney, and thymus where viral titers peaked at 2 to 4 d post-inoculation. Leucocytes collected from trout following waterborne challenge with IHNV were cocultured on EPC cell monolayers. These assays detected IHNV in leucocytes infected in vivo as early as 6 h post-exposure before the challenge virus had undergone replication. These data showed that leucocyte populations could serve as target cells in the initial phase of IHNV infection.
-
USDA-ARS?s Scientific Manuscript database
Influenza A virus (IAV) is widely circulating in the swine population and causes significant economic loss. To combat IAV infection the swine industry utilizes adjuvanted whole inactivated virus (WIV) vaccines. These vaccines can provide sterilizing immunity towards homologous virus but often have l...
-
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gabriel, Benjamin; Fiebig, Uwe; Hohn, Oliver
Although safety concerns preclude the use of live attenuated HIV vaccines in humans, they provide a useful system for identifying the elusive correlates of protective immunity in the SIV/macaque animal model. However, a number of pieces of evidence suggest that protection may result from prior occupancy of susceptible target cells by the vaccine virus rather than the immune response. To address this, we developed a Nef-deletion variant of an RT-SHIV whose active replication could be shut off by treatment with RT-inhibitors. Groups of macaques were inoculated with the ∆Nef-RT-SHIV and immune responses allowed to develop before antiretroviral treatment and subsequentmore » challenge with wild-type SIVmac239. Vaccinated animals either resisted infection fully or significantly controlled the subsequent viremia. However, there was no difference between animals undergoing replication of the vaccine virus and those without. This strongly suggests that competition for available target cells does not play a role in protection. - Highlights: • A Nef-deleted RT-SHIV was used as a live attenuated vaccine in macaques. • Vaccine virus replication was shut down to investigate its role in protection. • Ongoing vaccine virus replication did not appear to be necessary for protection. • An analysis of T- and B-cell responses failed to identify a correlate of protection.« less
-
Tsunekuni, Ryota; Hikono, Hirokazu; Saito, Takehiko
2014-08-15
Newcastle disease virus (NDV), also known as avian paramyxovirus (APMV) serotype 1, is used as a vaccine vector to express the hemagglutinin protein of avian influenza (AI) virus. However, use of live NDV recombinant vaccines expressing AI virus hemagglutinin is not desirable in emergency vaccination programs to control severe AI outbreaks in chickens, because commercial chickens often possess pre-existing NDV immunity induced by routine vaccination. Therefore, a novel vaccine vector is required for emergency vaccination of chickens to control AI during outbreaks. We investigated whether candidate APMV strains could be used as vaccine vectors that could evade the pre-existing immunity acquired by chickens through NDV vaccination and that would replicate in the mucosal tissues where AI virus primarily replicates. To this end, we examined strains of APMV serotypes 2 to 10 for their immunogenicity and replication in chickens with pre-existing immunity to NDV. APMV serotypes 2, 6, and 10 were the least cross-reactive to antibodies to NDV in hemagglutination inhibition and/or virus neutralization tests. Virus replication in mucosal tissues, as well as antibody response after oculonasal inoculation, was observed when 7-week-old chickens were challenged with APMV of serotype 2, 6, or 10. The APMV also replicated in mucosal tissues and induced antibody responses in chickens that had been vaccinated twice with NDV before challenge. These results warrant further study to develop vaccine vectors based on APMV serotype 2, 6, or 10 for emergency vaccination of chickens against AI. Copyright © 2014 Elsevier B.V. All rights reserved.
-
Inactivated recombinant plant virus protects dogs from a lethal challenge with canine parvovirus.
Langeveld, J P; Brennan, F R; Martínez-Torrecuadrada, J L; Jones, T D; Boshuizen, R S; Vela, C; Casal, J I; Kamstrup, S; Dalsgaard, K; Meloen, R H; Bendig, M M; Hamilton, W D
2001-06-14
A vaccine based upon a recombinant plant virus (CPMV-PARVO1), displaying a peptide derived from the VP2 capsid protein of canine parvovirus (CPV), has previously been described. To date, studies with the vaccine have utilized viable plant chimaeric particles (CVPs). In this study, CPMV-PARVO1 was inactivated by UV treatment to remove the possibility of replication of the recombinant plant virus in a plant host after manufacture of the vaccine. We show that the inactivated CVP is able to protect dogs from a lethal challenge with CPV following parenteral immunization with the vaccine. Dogs immunized with the inactivated CPMV-PARVO1 in adjuvant displayed no clinical signs of disease and shedding of CPV in faeces was limited following CPV challenge. All immunized dogs elicited high titres of peptide-specific antibody, which neutralized CPV in vitro. Levels of protection, virus shedding and VP2-specific antibody were comparable to those seen in dogs immunized with the same VP2- peptide coupled to keyhole limpet hemocyanin (KLH). Since plant virus-derived vaccines have the potential for cost-effective manufacture and are not known to replicate in mammalian cells, they represent a viable alternative to current replicating vaccine vectors for development of both human and veterinary vaccines.
-
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
-
Vaccination of rhesus macaques with a vif-deleted simian immunodeficiency virus proviral DNA vaccine
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sparger, Ellen E.; Dubie, Robert A.; Shacklett, Barbara L.
2008-05-10
Studies in non-human primates, with simian immunodeficiency virus (SIV) and simian/human immunodeficiency virus (SHIV) have demonstrated that live-attenuated viral vaccines are highly effective; however these vaccine viruses maintain a low level of pathogenicity. Lentivirus attenuation associated with deletion of the viral vif gene carries a significantly reduced risk for pathogenicity, while retaining the potential for virus replication of low magnitude in the host. This report describes a vif-deleted simian immunodeficiency virus (SIV)mac239 provirus that was tested as an attenuated proviral DNA vaccine by inoculation of female rhesus macaques. SIV-specific interferon-{gamma} enzyme-linked immunospot responses of low magnitude were observed after immunizationmore » with plasmid containing the vif-deleted SIV provirus. However, vaccinated animals displayed strong sustained virus-specific T cell proliferative responses and increasing antiviral antibody titers. These immune responses suggested either persistent vaccine plasmid expression or low level replication of vif-deleted SIV in the host. Immunized and unvaccinated macaques received a single high dose vaginal challenge with pathogenic SIVmac251. A transient suppression of challenge virus load and a greater median survival time was observed for vaccinated animals. However, virus loads for vaccinated and unvaccinated macaques were comparable by twenty weeks after challenge and overall survival curves for the two groups were not significantly different. Thus, a vif-deleted SIVmac239 proviral DNA vaccine is immunogenic and capable of inducing a transient suppression of pathogenic challenge virus, despite severe attenuation of the vaccine virus.« less
-
Foerster, Tessa; Streck, André Felipe; Speck, Stephanie; Selbitz, Hans-Joachim; Lindner, Thomas; Truyen, Uwe
2016-06-01
Inactivated whole-virus vaccines against porcine parvovirus (PPV) can prevent disease but not infection and virus shedding after heterologous virus challenge. Here, we showed that the same is true for a homologous challenge. Pregnant sows were vaccinated with an experimental inactivated vaccine based on PPV strain 27a. They were challenged on day 40 of gestation with the virulent porcine parvovirus PPV-27a from which the vaccine was prepared (homologous challenge). On day 90 of gestation, the fetuses from vaccinated sows were protected against disease, while the fetuses of the non-vaccinated sows (control group) exhibited signs of parvovirus disease. All gilts, whether vaccinated or not vaccinated, showed a boost of PPV-specific antibodies indicative of virus infection and replication. Low DNA copy numbers, but not infectious virus, could be demonstrated in nasal or rectal swabs of immunized sows, but high copy numbers of challenge virus DNA as well as infectious virus could both be demonstrated in non-vaccinated sows.
-
Li, Yongfeng; Li, Lian-Feng; Yu, Shaoxiong; Wang, Xiao; Zhang, Lingkai; Yu, Jiahui; Xie, Libao; Li, Weike; Ali, Razim; Qiu, Hua-Ji
2016-05-06
Commonly used tests based on wild-type viruses, such as immunostaining, cannot meet the demands for rapid detection of viral replication, high-throughput screening for antivirals, as well as for tracking viral proteins or virus transport in real time. Notably, the development of replicating-competent reporter-expressing viruses (RCREVs) has provided an excellent option to detect directly viral replication without the use of secondary labeling, which represents a significant advance in virology. This article reviews the applications of RCREVs in diagnostic and molecular virology, including rapid neutralization tests, high-throughput screening systems, identification of viral receptors and virus-host interactions, dynamics of viral infections in vitro and in vivo, vaccination approaches and others. However, there remain various challenges associated with RCREVs, including pathogenicity alterations due to the insertion of a reporter gene, instability or loss of the reporter gene expression, or attenuation of reporter signals in vivo. Despite all these limitations, RCREVs have become powerful tools for both basic and applied virology with the development of new technologies for generating RCREVs, the inventions of novel reporters and the better understanding of regulation of viral replication.
-
Duerrwald, Ralf; Schlegel, Michael; Bauer, Katja; Vissiennon, Théophile; Wutzler, Peter; Schmidtke, Michaela
2013-01-01
Recent epidemiological developments demonstrated that gene segments of swine influenza A viruses can account for antigenic changes as well as reduced drug susceptibility of pandemic influenza A viruses. This raises questions about the efficacy of preventive measures against swine influenza A viruses. Here, the protective effect of vaccination was compared with that of prophylactic Tamiflu® treatment against two Eurasian swine influenza A viruses. 11-week-old pigs were infected by aerosol nebulisation with high doses of influenza virus A/swine/Potsdam/15/1981 (H1N1/1981, heterologous challenge to H1N1 vaccine strain) and A/swine/Bakum/1832/2000 (H1N2/2000, homologous challenge to H1N2 vaccine strain) in two independent trials. In each trial (i) 10 pigs were vaccinated twice with a trivalent vaccine (RESPIPORC® FLU3; 28 and 7 days before infection), (ii) another 10 pigs received 150 mg/day of Tamiflu® for 5 days starting 12 h before infection, and (iii) 12 virus-infected pigs were left unvaccinated and untreated and served as controls. Both viruses replicated efficiently in porcine respiratory organs causing influenza with fever, dyspnoea, and pneumonia. Tamiflu® treatment as well as vaccination prevented clinical signs and significantly reduced virus shedding. Whereas after homologous challenge with H1N2/2000 no infectious virus in lung and hardly any lung inflammation were detected, the virus titre was not and the lung pathology was only partially reduced in H1N1/1981, heterologous challenged pigs. Tamiflu® application did not affect these study parameters. In conclusion, all tested preventive measures provided protection against disease. Vaccination additionally prevented virus replication and histopathological changes in the lung of homologous challenged pigs. PMID:23630601
-
Duerrwald, Ralf; Schlegel, Michael; Bauer, Katja; Vissiennon, Théophile; Wutzler, Peter; Schmidtke, Michaela
2013-01-01
Recent epidemiological developments demonstrated that gene segments of swine influenza A viruses can account for antigenic changes as well as reduced drug susceptibility of pandemic influenza A viruses. This raises questions about the efficacy of preventive measures against swine influenza A viruses. Here, the protective effect of vaccination was compared with that of prophylactic Tamiflu® treatment against two Eurasian swine influenza A viruses. 11-week-old pigs were infected by aerosol nebulisation with high doses of influenza virus A/swine/Potsdam/15/1981 (H1N1/1981, heterologous challenge to H1N1 vaccine strain) and A/swine/Bakum/1832/2000 (H1N2/2000, homologous challenge to H1N2 vaccine strain) in two independent trials. In each trial (i) 10 pigs were vaccinated twice with a trivalent vaccine (RESPIPORC® FLU3; 28 and 7 days before infection), (ii) another 10 pigs received 150 mg/day of Tamiflu® for 5 days starting 12 h before infection, and (iii) 12 virus-infected pigs were left unvaccinated and untreated and served as controls. Both viruses replicated efficiently in porcine respiratory organs causing influenza with fever, dyspnoea, and pneumonia. Tamiflu® treatment as well as vaccination prevented clinical signs and significantly reduced virus shedding. Whereas after homologous challenge with H1N2/2000 no infectious virus in lung and hardly any lung inflammation were detected, the virus titre was not and the lung pathology was only partially reduced in H1N1/1981, heterologous challenged pigs. Tamiflu® application did not affect these study parameters. In conclusion, all tested preventive measures provided protection against disease. Vaccination additionally prevented virus replication and histopathological changes in the lung of homologous challenged pigs.
-
USDA-ARS?s Scientific Manuscript database
Co-infections involving porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) contribute to a group of disease syndromes known as porcine circovirus-associated disease (PCVAD). Presumably, PRRSV infection enhances PCV2 replication as a result of modulation...
-
Jiwaji, Meesbah; Short, James Roswell; Dorrington, Rosemary Ann
2016-10-01
Tetraviruses are small, positive (+ve)-sense ssRNA viruses that infect the midgut cells of lepidopteran larvae. Providence virus (PrV) is the only member of the family Carmotetraviridae (previously Tetraviridae). PrV particles exhibit the characteristic tetraviral T=4 icosahedral symmetry, but PrV is distinct from other tetraviruses with respect to genome organization and viral non-structural proteins. Currently, PrV is the only tetravirus known to infect and replicate in lepidopteran cell culture lines. In this report we demonstrate, using immunofluorescence microscopy, that PrV infects and replicates in a human tissue culture cell line (HeLa), producing infectious virus particles. We also provide evidence for PrV replication in vitro in insect, mammalian and plant cell-free systems. This study challenges the long-held view that tetraviruses have a narrow host range confined to one or a few lepidopteran species and highlights the need to consider the potential for apparently non-infectious viruses to be transferred to new hosts in the laboratory.
-
Islam, Tanzila; Walkden-Brown, Stephen W; Renz, Katrin G; Islam, A F M Fakhrul; Ralapanawe, Sithara
2014-10-10
Vaccination is thought to contribute to an evolution in virulence of the Marek's disease virus (MDV) as vaccines prevent disease but not infection. We investigated the effects of co-infections at various intervals between Rispens/CVI988 vaccine virus (Rispens) and very virulent MDV (vvMDV) on the replication and shedding of each virus. The experiment used 600 ISA Brown layer chickens in 24 isolators with all treatments replicated in two isolators. Chickens were vaccinated with Rispens and/or challenged with the vvMDV isolate 02LAR on days 0, 5, or 10 post hatching providing vaccination to challenge intervals (VCI) of -10, -5, 0, 5 or 10 days with the negative values indicating challenge prior to vaccination. Peripheral blood lymphocytes (PBL), feathers and isolator exhaust dust were sampled between 7 and 56 days post infection (dpi) and subjected to quantitative real-time polymerase chain reaction (qPCR) to differentiate the two viruses. Overall Rispens significantly reduced the viral load of vvMDV in PBL and feather cells and shedding in dust. Similarly vvMDV significantly reduced the viral load of Rispens in PBL and feather cells but not in dust. VCI significantly influenced these relationships having strong positive and negative associations with load of vvMDV and Rispens respectively. Differences between the two viruses and their effects on each other were greatest in PBL and feathers, and least in dust. This study expands our understanding of the interaction between pathogenic and vaccinal viruses following vaccination with imperfect vaccines and has implications for selection of appropriate samples to test for vaccination success. Copyright © 2014 Elsevier B.V. All rights reserved.
-
Manoharan, Vinoth K; Khattar, Sunil K; Paldurai, Anandan; Kim, Shin-Hee; Samal, Siba K
2016-02-01
Newcastle disease is a highly contagious and economically important disease of poultry. Low-virulence Newcastle disease virus (NDV) strains such as B1 and LaSota have been used as live vaccines, with a proven track record of safety and efficacy. However, these vaccines do not completely prevent infection or virus shedding. Therefore, there is a need to enhance the immunogenicity of these vaccine strains. In this study, the effect of mutations in the conserved tyrosine residues of the F protein of vaccine strain LaSota was investigated. Our results showed that substitution of tyrosine at position 527 by alanine resulted in a hyperfusogenic virus with increased replication and immunogenicity. Challenge study with highly virulent NDV strain Texas GB showed that immunization of chickens with Y527A mutant virus provided 100% protection and no shedding of the challenge virus. This study suggests that the strain LaSota harbouring the Y527A mutation may represent a more efficacious vaccine.
-
Mandell, Robert B.; Koukuntla, Ramesh; Mogler, Laura J. K.; Carzoli, Andrea K.; Freiberg, Alexander N.; Holbrook, Michael R.; Martin, Brian K.; Staplin, William R.; Vahanian, Nicholas N.; Link, Charles J.; Flick, Ramon
2009-01-01
Virus-like particles (VLPs) present viral antigens in a native conformation and are effectively recognized by the immune system and therefore are considered as suitable and safe vaccine candidates against many viral diseases. Here we demonstrate that chimeric VLPs containing Rift Valley fever virus (RVFV) glycoproteins GN and GC, nucleoprotein N and the gag protein of Moloney murine leukemia virus represent an effective vaccine candidate against Rift Valley fever, a deadly disease in humans and livestock. Long-lasting humoral and cellular immune responses are demonstrated in a mouse model by the analysis of neutralizing antibody titers and cytokine secretion profiles. Vaccine efficacy studies were performed in mouse and rat lethal challenge models resulting in high protection rates. Taken together, these results demonstrate that replication-incompetent chimeric RVF VLPs are an efficient RVFV vaccine candidate. PMID:19932911
-
Kaplan, Bryan S; Torchetti, Mia K; Lager, Kelly M; Webby, Richard J; Vincent, Amy L
2017-09-01
In the fall of 2014, highly pathogenic avian influenza (HPAI) subtype H5N8 clade 2.3.4.4 was introduced into North America by migrating waterfowl from Asia where, through reassortment, novel HPAI H5N2 and H5N1 viruses emerged. Assess the susceptibility of pigs to HPAI H5N1, H5N2, and H5N8 clade 2.3.3.3 from North America. Pigs and trachea explants were inoculated with a representative panel of H5NX clade 2.3.4.4 HPAI viruses from North America. Nasal swabs, BALF, and sera were collected to assess replication and transmission in challenged and direct contact pigs by RRT-PCR, virus isolation, hemagglutination inhibition, and ELISA. Limited virus replication was restricted to the lower respiratory tract of challenged pigs, though absent in the nasal passages and trachea cultures, as determined by RRT-PCR in all samples. Seroconversion of inoculated pigs was detected by NP ELISA but was not reliably detected by antigen-specific hemagglutination inhibition. Boost with adjuvanted virus was required for the production of neutralizing antibodies to assess cross-reactivity between wild-type avian strains. All RRT-PCR and serology tests were negative for contact animals indicating a failure of transmission from primary inoculated pigs. H5NX clade 2.3.4.4 strains can replicate in the lower respiratory tract of swine upon high titer inoculation, though appear to be incapable of replication in swine nasal epithelium in vivo or ex vivo in trachea explants in culture. Infected pigs did not produce high levels of serum antibodies following infection. Collectively, our data show HPAI H5NX clade 2.3.4.4 viruses to be poorly adapted for replication and transmission in swine. © 2017 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.
-
De Vleeschauwer, Annebel R; Baras, Benoît; Kyriakis, Constantinos S; Jacob, Valérie; Planty, Camille; Giannini, Sandra L; Mossman, Sally; Van Reeth, Kristien
2012-08-10
We used the pig model of influenza to examine the efficacy of an AS03(A)-adjuvanted split H5N1 (A/Indonesia/05/2005) vaccine against challenge with a low pathogenic (LP) H5N1 avian influenza (AI) virus (duck/Minnesota/1525/1981) with only 85% amino acid homology in its HA1. Influenza seronegative pigs were vaccinated twice intramuscularly with adjuvanted vaccine at 3 antigen doses, unadjuvanted vaccine or placebo. All pigs were challenged 4 weeks after the second vaccination and euthanized 2 days later. After 2 vaccinations, all pigs in the adjuvanted vaccine groups had high hemagglutination inhibiting (HI) antibody titers to the vaccine strain (160-640), and lower antibody titers to the A/Vietnam/1194/04 H5N1 strain and to 2 LP H5 viruses with 90-91% amino acid homology to the vaccine strain (20-160). Eight out of 12 pigs had HI titers (10-20) to the challenge virus immediately before challenge. Neuraminidase inhibiting antibodies to the challenge virus were detected in most pigs (7/12) and virus neutralizing antibodies in all pigs. There was no antigen-dose dependent effect on the antibody response among the pigs immunized with adjuvanted H5N1 vaccines. After challenge, these pigs showed a complete clinical protection, reduced lung lesions and a significant protection against virus replication in the respiratory tract. Though the challenge virus showed only moderate replication efficiency in pigs, our study suggests that AS03(A)-adjuvanted H5N1 vaccine may confer a broader protection than generally assumed. The pros and cons of the pig as an H5N1 challenge model are also discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.
-
Penaranda, M.M.D.; Purcell, M.K.; Kurath, G.
2009-01-01
Host specificity is a phenomenon exhibited by all viruses. For the fish rhabdovirus infectious hematopoietic necrosis virus (IHNV), differential specificity of virus strains from the U and M genogroups has been established both in the field and in experimental challenges. In rainbow trout (Oncorhynchus mykiss), M IHNV strains are consistently more prevalent and more virulent than U IHNV. The basis of the differential ability of these two IHNV genogroups to cause disease in rainbow trout was investigated in live infection challenges with representative U and M IHNV strains. When IHNV was delivered by intraperitoneal injection, the mortality caused by U IHNV increased, indicating that the low virulence of U IHNV is partly due to inefficiency in entering the trout host. Analyses of in vivo replication showed that U IHNV consistently had lower prevalence and lower viral load than M IHNV during the course of infection. In analyses of the host immune response, M IHNV-infected fish consistently had higher and longer expression of innate immune-related genes such as Mx-1. This suggests that the higher virulence of M IHNV is not due to suppression of the immune response in rainbow trout. Taken together, the results support a kinetics hypothesis wherein faster replication enables M IHNV to rapidly achieve a threshold level of virus necessary to override the strong host innate immune response. ?? 2009 SGM.
-
Niederwerder, Megan C; Bawa, Bhupinder; Serão, Nick V L; Trible, Benjamin R; Kerrigan, Maureen A; Lunney, Joan K; Dekkers, Jack C M; Rowland, Raymond R R
2015-12-01
Coinfections involving porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) contribute to a group of disease syndromes known as porcine circovirus-associated disease (PCVAD). Presumably, PRRSV infection enhances PCV2 replication as a result of modulation of host immunity. The purpose of this study was to evaluate PCV2 replication and pathogenesis in pigs vaccinated with a PRRS modified live virus (MLV) vaccine and subsequently challenged with a combination of PRRSV and PCV2. During the early postchallenge period, the number of pigs with PRRSV-associated clinical signs was decreased, and average daily gain (ADG) was increased, in the vaccinated group, demonstrating the protective effect of PRRS vaccination. However, during the later postchallenge period, more pigs in the vaccinated group showed increased PCV2 viremia, decreased ADG, increased PCVAD clinical signs, and increased mortality. In this disease model, the early benefits of PRRSV vaccination were outweighed by the later amplification of PCVAD. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
-
Bawa, Bhupinder; Serão, Nick V. L.; Trible, Benjamin R.; Kerrigan, Maureen A.; Lunney, Joan K.; Dekkers, Jack C. M.; Rowland, Raymond R. R.
2015-01-01
Coinfections involving porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) contribute to a group of disease syndromes known as porcine circovirus-associated disease (PCVAD). Presumably, PRRSV infection enhances PCV2 replication as a result of modulation of host immunity. The purpose of this study was to evaluate PCV2 replication and pathogenesis in pigs vaccinated with a PRRS modified live virus (MLV) vaccine and subsequently challenged with a combination of PRRSV and PCV2. During the early postchallenge period, the number of pigs with PRRSV-associated clinical signs was decreased, and average daily gain (ADG) was increased, in the vaccinated group, demonstrating the protective effect of PRRS vaccination. However, during the later postchallenge period, more pigs in the vaccinated group showed increased PCV2 viremia, decreased ADG, increased PCVAD clinical signs, and increased mortality. In this disease model, the early benefits of PRRSV vaccination were outweighed by the later amplification of PCVAD. PMID:26446422
-
Kurath, Gael; Garver, Kyle; Purcell, Maureen K.; LaPatra, Scott E.
2010-01-01
Differential virulence of infectious hematopoietic necrosis virus (IHNV) isolates from the U and M phylogenetic subgroups is clearly evident in the Redfish Lake (RFL) strain of sockeye salmon Oncorhynchus nerka. In these fish, experimental immersion challenges with U isolates cause extremely high mortality and M isolates cause low or no mortality. When survivors of M virus immersion challenges were exposed to a secondary challenge with virulent U type virus they experienced high mortality, indicating that the primary M challenge did not elicit protective immunity. Delivery of a moderate dose (2 × 104 plaque-forming units [PFU]/fish) of virus by intraperitoneal injection challenge did not overcome RFL sockeye salmon resistance to M type IHNV. Injection challenge with a high dose (5 × 106 PFU/fish) of M type virus caused 10% mortality, and in this case survivors did develop protective immunity against a secondary U type virus challenge. Thus, although it is possible for M type IHNV to elicit cross-protective immunity in this disease model, it does not develop after immersion challenge despite entry, transient replication of M virus to low levels, stimulation of innate immune genes, and development of neutralizing antibodies in some fish.
-
USDA-ARS?s Scientific Manuscript database
We have previously shown that swine pretreated with a replication-defective human adenovirus vector (Ad5) containing the porcine type I interferon gene (poIFN-alpha/Beta) are sterilely protected when challenged one day later with Foot-and-Mouth Disease Virus (FMDV), but the dose required is relativ...
-
Jóźwik, A; Manteufel, J; Selbitz, H-J; Truyen, U
2009-10-01
The demonstration of field isolates of porcine parvovirus (PPV) that differ genetically and antigenically from vaccine strains of PPV raises the question of whether the broadly used inactivated vaccines can still protect sows against the novel viruses. Ten specific-pathogen-free primiparous sows were assigned to three groups and were vaccinated with one of two vaccines based on the old vaccine strains, or served as non-vaccinated controls. After insemination, all sows were challenged with the prototype genotype 2 virus, PPV-27a, on gestation day 41; fetuses were delivered on gestation day 90 and examined for virus infection. The fetuses of the vaccinated sows were protected against disease, but both the vaccinated and the non-vaccinated sows showed a marked increase in antibody titres after challenge infection, indicating replication of the challenge virus. All sows (vaccinated and non-vaccinated) shed the challenge virus for at least 10 days after infection, with no difference in the pattern or duration of virus shedding.
-
Replication, pathogenicity, shedding, and transmission of Zaire ebolavirus in pigs.
Kobinger, Gary P; Leung, Anders; Neufeld, James; Richardson, Jason S; Falzarano, Darryl; Smith, Greg; Tierney, Kevin; Patel, Ami; Weingartl, Hana M
2011-07-15
(See the editorial commentary by Bausch, on pages 179-81.) Reston ebolavirus was recently detected in pigs in the Philippines. Specific antibodies were found in pig farmers, indicating exposure to the virus. This important observation raises the possibility that pigs may be susceptible to Ebola virus infection, including from other species, such as Zaire ebolavirus (ZEBOV), and can transmit to other susceptible hosts. This study investigated whether ZEBOV, a species commonly reemerging in central Africa, can replicate and induce disease in pigs and can be transmitted to naive animals. Domesticated Landrace pigs were challenged through mucosal exposure with a total of 1 ×10(6) plaque-forming units of ZEBOV and monitored for virus replication, shedding, and pathogenesis. Using similar conditions, virus transmission from infected to naive animals was evaluated in a second set of pigs. Following mucosal exposure, pigs replicated ZEBOV to high titers (reaching 10(7) median tissue culture infective doses/mL), mainly in the respiratory tract, and developed severe lung pathology. Shedding from the oronasal mucosa was detected for up to 14 days after infection, and transmission was confirmed in all naive pigs cohabiting with inoculated animals. These results shed light on the susceptibility of pigs to ZEBOV infection and identify an unexpected site of virus amplification and shedding linked to transmission of infectious virus.
-
Welliver, Robert C; Oomens, Antonius; Wolf, Roman; Papin, James; Ivanov, Vadim; Preno, Alisha; Staats, Rachel; Piedra, Pedro; Yu, Zhongxin
2017-01-01
Abstract Background RSV bronchiolitis is the most common cause of hospitalization of infants in the US, and may lead to the development of long-term airway disease. Inactivated vaccines may lead to enhanced disease, while replicating vaccines have caused unacceptable degrees of illness, and may revert back to wild type. We developed an RSV vaccine lacking the gene for the M protein (Mnull RSV). The M protein is responsible for reassembly of the virus after it infects cells and expresses its proteins. Infant baboons vaccinated intranasally (IN) with Mnull RSV develop serum neutralizing antibody (NA) responses, but the virus does not replicate. Methods 2-week-old baboons (n = 12) were primed IN with 107 vaccine units of Mnull RSV or a control preparation, and a similar booster dose was given 4 weeks later. Mnull RSV vaccination did not cause tachypnea, airway inflammation or other signs of illness when compared with sham-vaccinated controls. Two weeks after boosting, all infants were challenged intratracheally with human RSV A2. We continuously monitored respiratory rates and levels of overall activity. On various days following challenge, we obtained BAL fluids for leukocyte counts and degree of virus replication, and evaluated alveolar-arterial oxygen gradients (A-a O2). Results Vaccinated animals (vs. unvaccinated controls) had lower respiratory rates (P = 0.0014), improved A-a O2 (P = 0.0063) and reduced viral replication (P = 0.0014). Activity scores were higher in vaccine recipients than in unvaccinated animals. Vaccine recipients also were primed for earlier serum and secretory neutralizing antibody responses, and greater airway lymphocyte responses. Airway lymphocyte numbers (but not antibody responses) were associated with lower respiratory rates and reduced viral replication (P < 0.01). Conclusion Vaccination intranasally with Mnull RSV protected infant baboons against an RSV challenge without causing respiratory disease or enhanced illness, and is a promising candidate for use in human infants. Lymphocyte responses to vaccination may play an equal or greater role in protection against RSV infection than antibody responses. Disclosures All authors: No reported disclosures.
-
2016-07-01
Single-Injection Trivalent Filovirus 428 Vaccine: Proof of Concept Study in Outbred Guinea Pigs . J Infect Dis. 429 29. Murin, C. D., M. L. Fusco, Z...Jahrling, and J. F. Smith. 2000. Recombinant RNA replicons derived from attenuated 442 Venezuelan equine encephalitis virus protect guinea pigs and...platform, 65 including ease of production and characterization, absence of virus replication concerns and the 66 robust immune stimulatory activity
-
Thakkar, Vidhi D; Cox, Robert M; Sawatsky, Bevan; da Fontoura Budaszewski, Renata; Sourimant, Julien; Wabbel, Katrin; Makhsous, Negar; Greninger, Alexander L; von Messling, Veronika; Plemper, Richard K
2018-04-15
The paramyxovirus replication machinery comprises the viral large (L) protein and phosphoprotein (P-protein) in addition to the nucleocapsid (N) protein, which encapsidates the single-stranded RNA genome. Common to paramyxovirus N proteins is a C-terminal tail (Ntail). The mechanistic role and relevance for virus replication of the structurally disordered central Ntail section are unknown. Focusing initially on members of the Morbillivirus genus, a series of measles virus (MeV) and canine distemper virus (CDV) N proteins were generated with internal deletions in the unstructured tail section. N proteins with large tail truncations remained bioactive in mono- and polycistronic minireplicon assays and supported efficient replication of recombinant viruses. Bioactivity of Ntail mutants extended to N proteins derived from highly pathogenic Nipah virus. To probe an effect of Ntail truncations on viral pathogenesis, recombinant CDVs were analyzed in a lethal CDV/ferret model of morbillivirus disease. The recombinant viruses displayed different stages of attenuation ranging from ameliorated clinical symptoms to complete survival of infected animals, depending on the molecular nature of the Ntail truncation. Reinfection of surviving animals with pathogenic CDV revealed robust protection against a lethal challenge. The highly attenuated virus was genetically stable after ex vivo passaging and recovery from infected animals. Mechanistically, gradual viral attenuation coincided with stepwise altered viral transcriptase activity in infected cells. These results identify the central Ntail section as a determinant for viral pathogenesis and establish a novel platform to engineer gradual virus attenuation for next-generation paramyxovirus vaccine design. IMPORTANCE Investigating the role of the paramyxovirus N protein tail domain (Ntail) in virus replication, we demonstrated in this study that the structurally disordered central Ntail region is a determinant for viral pathogenesis. We show that internal deletions in this Ntail region of up to 55 amino acids in length are compatible with efficient replication of recombinant viruses in cell culture but result in gradual viral attenuation in a lethal canine distemper virus (CDV)/ferret model. Mechanistically, we demonstrate a role of the intact Ntail region in the regulation of viral transcriptase activity. Recombinant viruses with Ntail truncations induce protective immunity against lethal challenge of ferrets with pathogenic CDV. This identification of the unstructured central Ntail domain as a nonessential paramyxovirus pathogenesis factor establishes a foundation for harnessing Ntail truncations for vaccine engineering against emerging and reemerging members of the paramyxovirus family. Copyright © 2018 American Society for Microbiology.
-
Lau, Yuk-Fai; Wright, Amber R.
2012-01-01
Live attenuated influenza vaccines (LAIVs) are effective in providing protection against influenza challenge in animal models and in preventing disease in humans. We previously showed that LAIVs elicit a range of immune effectors and that successful induction of pulmonary cellular and humoral immunity in mice requires pulmonary replication of the vaccine virus. An upper respiratory tract immunization (URTI) model was developed in mice to mimic the human situation, in which the vaccine virus does not replicate in the lower respiratory tract, allowing us to assess the protective efficacy of an H5N1 LAIV against highly pathogenic H5N1 virus challenge in the absence of significant pulmonary immunity. Our results show that, after one dose of an H5N1 LAIV, pulmonary influenza-specific lymphocytes are the main contributors to clearance of challenge virus from the lungs and that contributions of influenza-specific enzyme-linked immunosorbent assay (ELISA) antibodies in serum and splenic CD8+ T cells were negligible. Complete protection from H5N1 challenge was achieved after two doses of H5N1 LAIV and was associated with maturation of the antibody response. Although passive transfer of sera from mice that received two doses of vaccine prevented lethality in naive recipients following challenge, the mice showed significant weight loss, with high pulmonary titers of the H5N1 virus. These data highlight the importance of mucosal immunity in mediating optimal protection against H5N1 infection. Understanding the requirements for effective induction and establishment of these protective immune effectors in the respiratory tract paves the way for a more rational and effective vaccine approach in the future. PMID:22379093
-
Kim, Shin-Hee; Paldurai, Anandan; Xiao, Sa; Collins, Peter L.; Samal, Siba K.
2016-01-01
Naturally-occurring attenuated strains of Newcastle disease virus (NDV) are being developed as vaccine vectors for use in poultry and humans. However, some NDV strains, such as Beaudette C (BC), may retain too much virulence in poultry for safe use, and more highly attenuated strains may be suboptimally immunogenic. We therefore modified the BC strain by changing the multibasic cleavage site sequence of the F protein to the dibasic sequence of avirulent strain LaSota. Additionally, the BC, F, and HN proteins were modified in several ways to enhance virus replication. These modified BC-derived vectors and the LaSota strain were engineered to express the hemagglutin (HA) protein of H5N1 highly pathogenic influenza virus (HPAIV). In general, the modified BC-based vectors expressing HA replicated better than LaSota/HA, and expressed higher levels of HA protein. Pathogenicity tests indicated that all the modified viruses were highly attenuated in chickens. Based on in vitro characterization, two of the modified BC vectors were chosen for evaluation in chickens as vaccine vectors against H5N1 HPAIV A/Vietnam/1203/04. Immunization of chickens with rNDV vector vaccines followed by challenge with HPAIV demonstrated high levels of protection against clinical disease and mortality. However, only those chickens immunized with modified BC/HA in which residues 271–330 from the F protein had been replaced with the corresponding sequence from the NDV AKO strain conferred complete protection against challenge virus shedding. Our findings suggest that this modified rNDV can be used safely as a vaccine vector with enhanced replication, expression, and protective efficacy in avian species, and potentially in humans. PMID:24968158
-
Bialuk, Izabela; Whitney, Stephen; Andresen, Vibeke; Florese, Ruth H; Nacsa, Janos; Cecchinato, Valentina; Valeri, Valerio W; Heraud, Jean-Michel; Gordon, Shari; Parks, Robyn Washington; Montefiori, David C; Venzon, David; Demberg, Thorsten; Guroff, Marjorie Robert-; Landucci, Gary; Forthal, Donald N; Franchini, Genoveffa
2011-12-09
The role of antibodies directed against the hyper variable envelope region V1 of human immunodeficiency virus type 1 (HIV-1), has not been thoroughly studied. We show that a vaccine able to elicit strain-specific non-neutralizing antibodies to this region of gp120 is associated with control of highly pathogenic chimeric SHIV(89.6P) replication in rhesus macaques. The vaccinated animal that had the highest titers of antibodies to the amino terminus portion of V1, prior to challenge, had secondary antibody responses that mediated cell killing by antibody-dependent cellular cytotoxicity (ADCC), as early as 2 weeks after infection and inhibited viral replication by antibody-dependent cell-mediated virus inhibition (ADCVI), by 4 weeks after infection. There was a significant inverse correlation between virus level and binding antibody titers to the envelope protein, (R=-0.83, p=0.015), and ADCVI (R=-0.84 p=0.044). Genotyping of plasma virus demonstrated in vivo selection of three SHIV(89.6P) variants with changes in potential N-linked glycosylation sites in V1. We found a significant inverse correlation between virus levels and titers of antibodies that mediated ADCVI against all the identified V1 virus variants. A significant inverse correlation was also found between neutralizing antibody titers to SHIV(89.6) and virus levels (R=-0.72 p=0.0050). However, passive inoculation of purified immunoglobulin from animal M316, the macaque that best controlled virus, to a naïve macaque, resulted in a low serum neutralizing antibodies and low ADCVI activity that failed to protect from SHIV(89.6P) challenge. Collectively, while our data suggest that anti-envelope antibodies with neutralizing and non-neutralizing Fc(R-dependent activities may be important in the control of SHIV replication, they also demonstrate that low levels of these antibodies alone are not sufficient to protect from infection. Published by Elsevier Ltd.
-
Bialuk, Izabela; Whitney, Stephen; Andresen, Vibeke; Florese, Ruth H.; Nacsa, Janos; Cecchinato, Valentina; Valeri, Valerio W.; Heraud, Jean-Michel; Gordon, Shari; Parks, Robyn Washington; Montefiori, David C.; Venzon, David; Demberg, Thorsten; Guroff, Marjorie Robert; Landucci, Gary; Forthal, Donald N.; Franchini, Genoveffa
2011-01-01
The role of antibodies directed against the hyper variable envelope region V1 of human immunodeficiency virus type 1 (HIV-1), has not been thoroughly studied. We show that a vaccine able to elicit strain-specific non-neutralizing antibodies to this region of gp120 is associated with control of highly pathogenic chimeric SHIV89.6P replication in rhesus macaques. The vaccinated animal that had the highest titers of antibodies to the amino terminus portion of V1, prior to challenge, had secondary antibody responses that mediated cell killing by antibody-dependent cellular cytotoxicity (ADCC), as early as two weeks after infection and inhibited viral replication by antibody-dependent cell-mediated virus inhibition (ADCVI), by four weeks after infection. There was a significant inverse correlation between virus level and binding antibody titers to the envelope protein, (R = -0.83, p 0.015), and ADCVI (R = -0.84 p=0.044). Genotyping of plasma virus demonstrated in vivo selection of three SHIV89.6P variants with changes in potential N-linked glycosylation sites in V1. We found a significant inverse correlation between virus levels and titers of antibodies that mediated ADCVI against all the identified V1 virus variants. A significant inverse correlation was also found between neutralizing antibody titers to SHIV89.6 and virus levels (R = -0.72 p =0.0050). However, passive inoculation of purified immunoglobulin from animal M316, the macaque that best controlled virus, to a naïve macaque, resulted in a low serum neutralizing antibodies and low ADCVI activity that failed to protect from SHIV89.6P challenge. Collectively, while our data suggest that anti-envelope antibodies with neutralizing and non-neutralizing FcγR-dependent activities may be important in the control of SHIV replication, they also demonstrate that low levels of these antibodies alone are not sufficient to protect from infection. PMID:22037204
-
Profiling of Genes Related to Cross Protection and Competition for NbTOM1 by HLSV and TMV
Wen, Yi; Lim, Grace Xiao-Yun; Wong, Sek-Man
2013-01-01
Cross protection is the phenomenon through which a mild strain virus suppresses symptoms induced by a closely related severe strain virus in infected plants. Hibiscus latent Singapore virus (HLSV) and Tobacco mosaic virus (TMV) are species within the genus tobamovirus. HLSV can protect Nicotiana benthamiana against TMV-U1 strain, resulting in mild symptoms instead of severe systemic necrosis. The mechanism of cross protection between HLSV and TMV is unknown. In the past, some researchers suggest that the protecting virus strain might occupy virus-specific replication sites within a cell leaving no room for the challenge virus. Quantitative real-time RT-PCR was performed to detect viral RNA levels during cross protection. HLSV accumulation increased in cross protected plants compared with that of single HLSV infected plants, while TMV decreased in cross protected plants. This suggests that there is a competition for host factors between HLSV and TMV for replication. To investigate the mechanism under the cross protection between HLSV and TMV, microarray analysis was conducted to examine the transcriptional levels of global host genes during cross protection, using Tobacco Gene Expression Microarray, 4x44 k slides. The transcriptional level of some host genes corresponded to accumulation level of TMV. Some host genes were up-regulated only by HLSV. Tobamovirus multiplication gene 1 (TOM1), essential for tobamovirus multiplication, was involved in competition for replication by HLSV and TMV during cross protection. Both HLSV and TMV accumulation decreased when NbTOM1 was silenced. A large quantity of HLSV resulted in decreased TMV accumulation in HLSV+TMV (100:1) co-infection. These results indicate that host genes involved in the plant defense response and virus multiplication are up-regulated by challenge virus TMV but not by protecting virus HLSV during cross protection. PMID:24023899
-
Celma, Cristina C. P.; Boyce, Mark; van Rijn, Piet A.; Eschbaumer, Michael; Wernike, Kerstin; Hoffmann, Bernd; Beer, Martin; Haegeman, Andy; De Clercq, Kris
2013-01-01
Since 1998, 9 of the 26 serotypes of bluetongue virus (BTV) have spread throughout Europe, and serotype 8 has suddenly emerged in northern Europe, causing considerable economic losses, direct (mortality and morbidity) but also indirect, due to restriction in animal movements. Therefore, many new types of vaccines, particularly subunit vaccines, with improved safety and efficacy for a broad range of BTV serotypes are currently being developed by different laboratories. Here we exploited a reverse genetics-based replication-deficient BTV serotype 1 (BTV-1) (disabled infectious single cycle [DISC]) strain to generate a series of DISC vaccine strains. Cattle and sheep were vaccinated with these viruses either singly or in cocktail form as a multivalent vaccine candidate. All vaccinated animals were seroconverted and developed neutralizing antibody responses to their respective serotypes. After challenge with the virulent strains at 21 days postvaccination, vaccinated animals showed neither any clinical reaction nor viremia. Further, there was no interference with protection with a multivalent preparation of six distinct DISC viruses. These data indicate that a very-rapid-response vaccine could be developed based on which serotypes are circulating in the population at the time of an outbreak. PMID:23824810
-
Celma, Cristina C P; Boyce, Mark; van Rijn, Piet A; Eschbaumer, Michael; Wernike, Kerstin; Hoffmann, Bernd; Beer, Martin; Haegeman, Andy; De Clercq, Kris; Roy, Polly
2013-09-01
Since 1998, 9 of the 26 serotypes of bluetongue virus (BTV) have spread throughout Europe, and serotype 8 has suddenly emerged in northern Europe, causing considerable economic losses, direct (mortality and morbidity) but also indirect, due to restriction in animal movements. Therefore, many new types of vaccines, particularly subunit vaccines, with improved safety and efficacy for a broad range of BTV serotypes are currently being developed by different laboratories. Here we exploited a reverse genetics-based replication-deficient BTV serotype 1 (BTV-1) (disabled infectious single cycle [DISC]) strain to generate a series of DISC vaccine strains. Cattle and sheep were vaccinated with these viruses either singly or in cocktail form as a multivalent vaccine candidate. All vaccinated animals were seroconverted and developed neutralizing antibody responses to their respective serotypes. After challenge with the virulent strains at 21 days postvaccination, vaccinated animals showed neither any clinical reaction nor viremia. Further, there was no interference with protection with a multivalent preparation of six distinct DISC viruses. These data indicate that a very-rapid-response vaccine could be developed based on which serotypes are circulating in the population at the time of an outbreak.
-
Neutralizing antibody fails to impact the course of Ebola virus infection in monkeys.
Oswald, Wendelien B; Geisbert, Thomas W; Davis, Kelly J; Geisbert, Joan B; Sullivan, Nancy J; Jahrling, Peter B; Parren, Paul W H I; Burton, Dennis R
2007-01-01
Prophylaxis with high doses of neutralizing antibody typically offers protection against challenge with viruses producing acute infections. In this study, we have investigated the ability of the neutralizing human monoclonal antibody, KZ52, to protect against Ebola virus in rhesus macaques. This antibody was previously shown to fully protect guinea pigs from infection. Four rhesus macaques were given 50 mg/kg of neutralizing human monoclonal antibody KZ52 intravenously 1 d before challenge with 1,000 plaque-forming units of Ebola virus, followed by a second dose of 50 mg/kg antibody 4 d after challenge. A control animal was exposed to virus in the absence of antibody treatment. Passive transfer of the neutralizing human monoclonal antibody not only failed to protect macaques against challenge with Ebola virus but also had a minimal effect on the explosive viral replication following infection. We show that the inability of antibody to impact infection was not due to neutralization escape. It appears that Ebola virus has a mechanism of infection propagation in vivo in macaques that is uniquely insensitive even to high concentrations of neutralizing antibody.
-
Rouxel, Ronan Nicolas; Svitek, Nicholas; von Messling, Veronika
2009-08-06
CDV infects a broad range of carnivores, and over the past decades it has caused outbreaks in a variety of wild carnivore populations. Since the currently available live-attenuated vaccine is not sufficiently safe in these highly susceptible species, we produced a chimeric virus combining the replication complex of the measles Moraten vaccine strain with the envelope of a recent CDV wild type isolate. The resulting virus did not cause disease or immunosuppression in ferrets and conferred protection from challenge with a lethal wild type strain, demonstrating its potential value for wildlife conservation efforts.
-
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.
-
Cross-protection in nonhuman primates against Argentine hemorrhagic fever.
Weissenbacher, M C; Coto, C E; Calello, M A; Rondinone, S N; Damonte, E B; Frigerio, M J
1982-01-01
The susceptibility of the marmoset Callithrix jacchus to Tacaribe virus infection was investigated to perform cross-protection studies between Junin and Tacaribe viruses. Five marmosets inoculated with Tacaribe virus failed to show any signs of disease, any alterations in erythrocyte, leukocyte, reticulocyte, and platelet counts or any changes in hematocrit or hemoglobin values. No Tacaribe virus could be recovered from blood at any time postinfection. Anti-Tacaribe neutralizing antibodies appeared 3 weeks postinfection. The five Tacaribe-infected marmosets and four noninfected controls were challenged with the pathogenic strain of Junin virus on day 60 post-Tacaribe infection. The former group showed no signs of disease, no viremia, and no challenge virus replication, whereas the control group exhibited the typical symptoms of Argentine hemorrhagic fever, high viremia, and viral titers in organs. Soon after challenge, the Tacaribe-protected marmosets synthesized neutralizing antibodies against Junin virus. These results indicate that the marmoset C. jacchus can be considered an experimental model for protection studies with arenaviruses and that the Tacaribe virus could be considered as a potential vaccine against Junin virus. PMID:6276301
-
Roh, Ha-Jung; Jordan, Brian J; Hilt, Deborah A; Ard, Mary B; Jackwood, Mark W
2015-03-01
studies in our laboratory showed that the Arkansas-Delmarva Poultry Industry (Ark-DPI) vaccine given to 1-day-old chickens by hatchery spray cabinet replicated poorly and failed to adequately protect broilers against homologous virus challenge, whereas the same vaccine given by eye-drop did replicate and the birds were protected following homologous virus challenge. To determine if mechanical damage following spray application plays a role in failure of the Ark-DPI vaccine, we examined the morphology of three Ark-DPI vaccines from different manufacturers using an electron microscope and included a Massachusetts (Mass) vaccine as control. One of the Ark-DPI vaccines (vaccine A) and the Mass vaccine had significantly (P < 0.005) fewer spikes than the other two Ark-DPI vaccines. We also found that the Ark-DPI and Mass vaccines had significantly (P < 0.005) fewer spike proteins per virus particle when compared to their respective challenge viruses. This observation is interesting and may provide some insight into the mechanism behind infectious bronchitis virus attenuation. No obvious differences were observed in virus morphology and no consistent trend in the number of spikes per virion was found in before- and after-spray samples. We also determined the vaccine titer before and after spray in embryonated eggs and found that both Ark-DPI and Mass vaccines had a similar drop in titer, 0.40 logi and 0.310 logi, respec10ively. Based on these data, it appears that mechanical damage to the Ark-DPI vaccine is not occurring when delivered by a hatchery spray cabinet, suggesting that some other factor is contributing to the failure of that vaccine when given by that method.
-
Klingbeil, Katharina; Lange, Elke; Blohm, Ulrike; Teifke, Jens P; Mettenleiter, Thomas C; Fuchs, Walter
2015-03-02
Influenza is an important respiratory disease of pigs, and may lead to novel human pathogens like the 2009 pandemic H1N1 swine-origin influenza virus (SoIV). Therefore, improved influenza vaccines for pigs are required. Recently, we demonstrated that single intranasal immunization with a hemagglutinin (HA)-expressing pseudorabies virus recombinant of vaccine strain Bartha (PrV-Ba) protected pigs from H1N1 SoIV challenge (Klingbeil et al., 2014). Now we investigated enhancement of efficacy by prime-boost vaccination and/or intramuscular administration. Furthermore, a novel PrV-Ba recombinant expressing codon-optimized N1 neuraminidase (NA) was included. In vitro replication of this virus was only slightly affected compared to parental virus. Unlike HA, the abundantly expressed NA was efficiently incorporated into PrV particles. Immunization of pigs with the two PrV recombinants, either singly or in combination, induced B cell proliferation and the expected SoIV-specific antibodies, whose titers increased substantially after boost vaccination. After immunization of animals with either PrV recombinant H1N1 SoIV challenge virus replication was significantly reduced compared to PrV-Ba vaccinated or naïve controls. Protective efficacy of HA-expressing PrV was higher than of NA-expressing PrV, and not significantly enhanced by combination. Despite higher serum antibody titers obtained after intramuscular immunization, transmission of challenge virus to naïve contact animals was only prevented after intranasal prime-boost vaccination with HA-expressing PrV-Ba. Copyright © 2015 Elsevier B.V. All rights reserved.
-
Patterns of HIV/SIV Prevention and Control by Passive Antibody Immunization.
Yamamoto, Hiroyuki; Matano, Tetsuro
2016-01-01
Neutralizing antibody (NAb) responses are promising immune effectors for control of human immunodeficiency virus (HIV) infection. Protective activity and mechanisms of immunodeficiency virus-specific NAbs have been increasingly scrutinized in animals infected with simian immunodeficiency virus (SIV), chimeric simian/human immunodeficiency virus (SHIV) and related viruses. Studies on such models have unraveled a previously underscored protective potential against in vivo immunodeficiency virus replication. Pre-challenge NAb titers feasibly provide sterile protection from SIV/SHIV infection by purging the earliest onset of viral replication and likely modulate innate immune cell responses. Sufficient sub-sterile NAb titers after established infection also confer dose-dependent reduction of viremia, and in certain earlier time frames augment adaptive immune cell responses and even provide rebound-free viral control. Here, we provide an overview of the obtained patterns of SIV/SHIV protection and viral control by various types of NAb passive immunizations and discuss how these notions may be extrapolated to NAb-based clinical control of HIV infection.
-
Yi, MinKyung; Hu, Fengyu; Joyce, Michael; Saxena, Vikas; Welsch, Christoph; Chavez, Deborah; Guerra, Bernadette; Yamane, Daisuke; Veselenak, Ronald; Pyles, Rick; Walker, Christopher M.; Tyrrell, Lorne; Bourne, Nigel; Lanford, Robert E.
2014-01-01
ABSTRACT Persistent infection is a key feature of hepatitis C virus (HCV). However, chimpanzee infections with cell culture-derived viruses (JFH1 or related chimeric viruses that replicate efficiently in cell culture) have been limited to acute-transient infections with no pathogenicity. Here, we report persistent infection with chronic hepatitis in a chimpanzee challenged with cell culture-derived genotype 1a virus (H77S.2) containing 6 cell culture-adaptive mutations. Following acute-transient infection with a chimeric H77/JFH1 virus (HJ3-5), intravenous (i.v.) challenge with 106 FFU H77S.2 virus resulted in immediate seroconversion and, following an unusual 4- to 6-week delay, persistent viremia accompanied by alanine aminotransferase (ALT) elevation, intrahepatic innate immune responses, and diffuse hepatopathy. This first persistent infection with cell culture-produced HCV provided a unique opportunity to assess evolution of cell culture-adapted virus in vivo. Synonymous and nonsynonymous nucleotide substitution rates were greatest during the first 8 weeks of infection. Of 6 cell culture-adaptive mutations in H77S.2, Q1067R (NS3) had reverted to Q1067 and S2204I (NS5A) was replaced by T2204 within 8 weeks of infection. By 62 weeks, 4 of 6 mutations had reverted to the wild-type sequence, and all reverted to the wild-type sequence by 194 weeks. The data suggest H77S.2 virus has greater potential for persistence and pathogenicity than JFH1 and demonstrate both the capacity of a nonfit virus to persist for weeks in the liver in the absence of detectable viremia as well as strong selective pressure against cell culture-adaptive mutations in vivo. IMPORTANCE This study shows that mutations promoting the production of infectious genotype 1a HCV in cell culture have the opposite effect and attenuate replication in the liver of the only fully permissive animal species other than humans. It provides the only example to date of persistent infection in a chimpanzee challenged with cell culture-produced virus and provides novel insight into the forces shaping molecular evolution of that virus during 5 years of persistent infection. It demonstrates that a poorly fit virus can replicate for weeks within the liver in the absence of detectable viremia, an observation that expands current concepts of HCV pathogenesis and that is relevant to relapses observed with direct-acting antiviral therapies. PMID:24429362
-
RNA viruses and microRNAs: challenging discoveries for the 21st century
Swaminathan, Gokul; Martin-Garcia, Julio
2013-01-01
RNA viruses represent the predominant cause of many clinically relevant viral diseases in humans. Among several evolutionary advantages acquired by RNA viruses, the ability to usurp host cellular machinery and evade antiviral immune responses is imperative. During the past decade, RNA interference mechanisms, especially microRNA (miRNA)-mediated regulation of cellular protein expression, have revolutionized our understanding of host-viral interactions. Although it is well established that several DNA viruses express miRNAs that play crucial roles in their pathogenesis, expression of miRNAs by RNA viruses remains controversial. However, modulation of the miRNA machinery by RNA viruses may confer multiple benefits for enhanced viral replication and survival in host cells. In this review, we discuss the current literature on RNA viruses that may encode miRNAs and the varied advantages of engineering RNA viruses to express miRNAs as potential vectors for gene therapy. In addition, we review how different families of RNA viruses can alter miRNA machinery for productive replication, evasion of antiviral immune responses, and prolonged survival. We underscore the need to further explore the complex interactions of RNA viruses with host miRNAs to augment our understanding of host-virus interplay. PMID:24046280
-
Son, K; Kim, Y-K; Oem, J-K; Jheong, W-H; Sleeman, J M; Jeong, J
2018-06-01
Outbreaks of highly pathogenic avian influenza (HPAI) have been reported worldwide. Wild waterfowl play a major role in the maintenance and transmission of HPAI. Highly pathogenic avian influenza subtype H5N6 and H5N8 viruses simultaneously emerged in South Korea. In this study, the comparative pathogenicity and infectivity of Clade 2.3.4.4 Group B H5N8 and Group C H5N6 viruses were evaluated in Mandarin duck (Aix galericulata). None of the ducks infected with H5N6 or H5N8 viruses showed clinical signs or mortality. Serological assays revealed that the HA antigenicity of H5N8 and H5N6 viruses was similar to each other. Moreover, both the viruses did not replicate after cross-challenging with H5N8 and H5N6 viruses, respectively, as the second infection. Although both the viruses replicated in most of the internal organs of the ducks, viral replication and shedding through cloaca were higher in H5N8-infected ducks than in H5N6-infected ducks. The findings of this study provide preliminary information to help estimate the risks involved in further evolution and dissemination of Clade 2.3.4.4 HPAI viruses among wild birds. © 2017 The Authors. Transboundary and Emerging Diseases Published by Blackwell Verlag GmbH.
-
Alexander, Jeff; Ward, Simone; Mendy, Jason; Manayani, Darly J; Farness, Peggy; Avanzini, Jenny B; Guenther, Ben; Garduno, Fermin; Jow, Lily; Snarsky, Victoria; Ishioka, Glenn; Dong, Xin; Vang, Lo; Newman, Mark J; Mayall, Tim
2012-01-01
Influenza virus remains a significant health and social concern in part because of newly emerging strains, such as avian H5N1 virus. We have developed a prototype H5N1 vaccine using a recombinant, replication-competent Adenovirus serotype 4 (Ad4) vector, derived from the U.S. military Ad4 vaccine strain, to express the hemagglutinin (HA) gene from A/Vietnam/1194/2004 influenza virus (Ad4-H5-Vtn). Our hypothesis is that a mucosally-delivered replicating Ad4-H5-Vtn recombinant vector will be safe and induce protective immunity against H5N1 influenza virus infection and disease pathogenesis. The Ad4-H5-Vtn vaccine was designed with a partial deletion of the E3 region of Ad4 to accommodate the influenza HA gene. Replication and growth kinetics of the vaccine virus in multiple human cell lines indicated that the vaccine virus is attenuated relative to the wild type virus. Expression of the HA transgene in infected cells was documented by flow cytometry, western blot analysis and induction of HA-specific antibody and cellular immune responses in mice. Of particular note, mice immunized intranasally with the Ad4-H5-Vtn vaccine were protected against lethal H5N1 reassortant viral challenge even in the presence of pre-existing immunity to the Ad4 wild type virus. Several non-clinical attributes of this vaccine including safety, induction of HA-specific humoral and cellular immunity, and efficacy were demonstrated using an animal model to support Phase 1 clinical trial evaluation of this new vaccine.
-
Inhibitory effects of bee venom and its components against viruses in vitro and in vivo.
Uddin, Md Bashir; Lee, Byeong-Hoon; Nikapitiya, Chamilani; Kim, Jae-Hoon; Kim, Tae-Hwan; Lee, Hyun-Cheol; Kim, Choul Goo; Lee, Jong-Soo; Kim, Chul-Joong
2016-12-01
Bee venom (BV) from honey bee (Apis Melifera L.) contains at least 18 pharmacologically active components including melittin (MLT), phospholipase A 2 (PLA 2 ), and apamin etc. BV is safe for human treatments dose dependently and proven to possess different healing properties including antibacterial and antiparasitidal properties. Nevertheless, antiviral properties of BV have not well investigated. Hence, we identified the potential antiviral properties of BV and its component against a broad panel of viruses. Co-incubation of non-cytotoxic amounts of BV and MLT, the main component of BV, significantly inhibited the replication of enveloped viruses such as Influenza A virus (PR8), Vesicular Stomatitis Virus (VSV), Respiratory Syncytial Virus (RSV), and Herpes Simplex Virus (HSV). Additionally, BV and MLT also inhibited the replication of non-enveloped viruses such as Enterovirus-71 (EV-71) and Coxsackie Virus (H3). Such antiviral properties were mainly explained by virucidal mechanism. Moreover, MLT protected mice which were challenged with lethal doses of pathogenic influenza A H1N1 viruses. Therefore, these results provides the evidence that BV and MLT could be a potential source as a promising antiviral agent, especially to develop as a broad spectrum antiviral agent.
-
Yang, Lijuan; Sanchez, Anthony; Ward, Jerrold M; Murphy, Brian R; Collins, Peter L; Bukreyev, Alexander
2008-08-01
Ebola virus (EBOV) causes outbreaks of a highly lethal hemorrhagic fever in humans. The virus can be transmitted by direct contact as well as by aerosol and is considered a potential bioweapon. Because direct immunization of the respiratory tract should be particularly effective against infection of mucosal surfaces, we previously developed an intranasal vaccine based on replication-competent human parainfluenza virus type 3 (HPIV3) expressing EBOV glycoprotein GP (HPIV3/EboGP) and showed that it is immunogenic and protective against a high dose parenteral EBOV challenge. However, because the adult human population has considerable immunity to HPIV3, which is a common human pathogen, replication and immunogenicity of the vaccine in this population might be greatly restricted. Indeed, in the present study, replication of the vaccine in the respiratory tract of HPIV3-immune guinea pigs was found to be restricted to undetectable levels. This restriction appeared to be based on both neutralizing antibodies and cellular or other components of the immunity to HPIV3. Surprisingly, even though replication of HPIV3/EboGP was highly restricted in HPIV3-immune animals, it induced a high level of EBOV-specific antibodies that nearly equaled that obtained in HPIV3-naive animals. We also show that the previously demonstrated presence of functional GP in the vector particle was not associated with increased replication in the respiratory tract nor with spread beyond the respiratory tract of HPIV3-naive guinea pigs, indicating that expression and functional incorporation of the attachment/penetration glycoprotein of this systemic virus did not mediate a change in tissue tropism.
-
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.
-
USDA-ARS?s Scientific Manuscript database
Bovine respiratory syncytial virus (BRSV) is a leading cause of bovine respiratory disease in cattle worldwide. MicroRNAs have been suggested to play a role in viral infections via their regulation of cellular molecules involved in either viral replication or in host innate immunity to infection. Th...
-
USDA-ARS?s Scientific Manuscript database
The safety and efficacy of an experimental, replication-deficient, human adenovirus-vectored foot-and-mouth disease virus (FMDV) serotype A24 Cruzeiro capsid-based subunit vaccine (AdtA24) was examined in eight independent cattle studies. AdtA24 non-adjuvanted vaccine was administered intramuscularl...
-
Boyoglu-Barnum, Seyhan; Gaston, Kelsey A; Todd, Sean O; Boyoglu, Cemil; Chirkova, Tatiana; Barnum, Thomas R; Jorquera, Patricia; Haynes, Lia M; Tripp, Ralph A; Moore, Martin L; Anderson, Larry J
2013-10-01
Respiratory syncytial virus (RSV) belongs to the family Paramyxoviridae and is the single most important cause of serious lower respiratory tract infections in young children, yet no highly effective treatment or vaccine is available. Increased airway resistance and increased airway mucin production are two manifestations of RSV infection in children. RSV rA2-line19F infection induces pulmonary mucous production and increased breathing effort in BALB/c mice and provides a way to assess these manifestations of RSV disease in an animal model. In the present study, we investigated the effect of prophylactic treatment with the F(ab')2 form of the anti-G protein monoclonal antibody (MAb) 131-2G on disease in RSV rA2-line19F-challenged mice. F(ab')2 131-2G does not affect virus replication. It and the intact form that does decrease virus replication prevented increased breathing effort and airway mucin production, as well as weight loss, pulmonary inflammatory-cell infiltration, and the pulmonary substance P and pulmonary Th2 cytokine levels that occur in mice challenged with this virus. These data suggest that the RSV G protein contributes to prominent manifestations of RSV disease and that MAb 131-2G can prevent these manifestations of RSV disease without inhibiting virus infection.
-
An HSV-2 Trivalent Vaccine Is Immunogenic in Rhesus Macaques and Highly Efficacious in Guinea Pigs.
Awasthi, Sita; Hook, Lauren M; Shaw, Carolyn E; Pahar, Bapi; Stagray, Jacob A; Liu, David; Veazey, Ronald S; Friedman, Harvey M
2017-01-01
A genital herpes vaccine is urgently needed to prevent pain and suffering, reduce the incidence of neonatal herpes, and decrease the risk of HIV acquisition and transmission that accompanies genital infection. We evaluated a trivalent HSV-2 subunit antigen vaccine administered with CpG and alum in rhesus macaques and guinea pigs. The vaccine contains glycoproteins C, D and E (gC2, gD2, gE2) to block virus entry by gD2 and immune evasion by gC2 and gE2. In rhesus macaques, the trivalent vaccine induced plasma and mucosa neutralizing antibodies, antibodies that block gC2 and gE2 immune evasion activities, and stimulated CD4 T cell responses. After intravaginal challenge, a self-limited vaginal infection of brief duration was detected by histopathology and immunohistochemistry in naïve, but not in trivalent immunized macaques. Vaccine efficacy was evaluated in female guinea pigs. Animals were mock immunized, or immunized with gD2, the trivalent vaccine or the trivalent vaccine followed by a booster dose of gD2 (trivalent + gD2). The trivalent and trivalent + gD2 groups were 97% and 99% efficacious, respectively in preventing genital lesions and both outperformed gD2 alone. As a marker of transmission risk, vaginal swabs were evaluated daily for HSV-2 DNA and replication competent virus between five and seven weeks after challenge. HSV-2 DNA shedding was reduced in all groups compared with mock. Shedding of replication competent virus occurred on fewer days in the trivalent than gD2 immunized animals while the trivalent + gD2 group had no shedding of replication competent virus. Overall, the trivalent group had genital lesions on < 1% days and shedding of replication competent virus on 0.2% days. The vaccine has outstanding potential for prevention of genital herpes in humans.
-
New viruses for cancer therapy: meeting clinical needs
Miest, Tanner S.; Cattaneo, Roberto
2014-01-01
Early-stage clinical trials of oncolytic virotherapy have reported the safety of several virus platforms, and viruses from three families have progressed to advanced efficacy trials. In addition, preclinical studies have established proof-of-principle for many new genetic engineering strategies. Thus, the virotherapy field now has available a diverse collection of viruses that are equipped to address unmet clinical needs owing to improved systemic administration, greater tumour specificity and enhanced oncolytic efficacy. The current key challenge for the field is to develop viruses that replicate with greater efficiency within tumours while achieving therapeutic synergy with currently available treatments. PMID:24292552
-
Biological Characteristics of H9N2 Avian Influenza Viruses from Healthy Chickens in Shanghai, China.
Shi, Qingfeng; Wang, Qianli; Ju, Liwen; Xiong, Haiyan; Chen, Yue; Jiang, Lufang; Jiang, Qingwu
2016-12-10
BACKGROUND H9N2 avian influenza viruses that circulate in domestic poultry in eastern China pose challenges to human health. However, few studies have compared the biological characteristics of H9N2 viruses isolated from healthy chickens in Shanghai. MATERIAL AND METHODS Three H9N2 viruses - CK/SH/Y1/07, CK/SH/Y1/02, and CK/SH/23/13 - isolated from healthy chickens in Shanghai between 2002 and 2013, were selected and their biological characteristics were determined. RESULTS All 3 H9N2 viruses showed a preference for both the avian- and human-like receptors, and they replicated well in MDCK and A549 cells. All H9N2 viruses were non-pathogenic to mini-pigs and were detected in the trachea and lung tissues. The CK/SH/Y1/07 and CK/SH/Y1/02 viruses were transmitted to mini-pigs through direct-contact or respiratory droplet exposure, but CK/SH/23/13 virus was not. CONCLUSIONS These results suggest that H9N2 viruses isolated from healthy chickens in Shanghai efficiently replicate and transmit among pigs and other mammals.
-
Garrison, Aura R; Giomarelli, Barbara G; Lear-Rooney, Calli M; Saucedo, Carrie J; Yellayi, Srikanth; Krumpe, Lauren R H; Rose, Maura; Paragas, Jason; Bray, Mike; Olinger, Gene G; McMahon, James B; Huggins, John; O'Keefe, Barry R
2014-12-01
The cyanobacterial lectin scytovirin (SVN) binds with high affinity to mannose-rich oligosaccharides on the envelope glycoprotein (GP) of a number of viruses, blocking entry into target cells. In this study, we assessed the ability of SVN to bind to the envelope GP of Zaire Ebola virus (ZEBOV) and inhibit its replication. SVN interacted specifically with the protein's mucin-rich domain. In cell culture, it inhibited ZEBOV replication with a 50% virus-inhibitory concentration (EC50) of 50 nM, and was also active against the Angola strain of the related Marburg virus (MARV), with a similar EC50. Injected subcutaneously in mice, SVN reached a peak plasma level of 100 nm in 45 min, but was cleared within 4h. When ZEBOV-infected mice were given 30 mg/kg/day of SVN by subcutaneous injection every 6h, beginning the day before virus challenge, 9 of 10 animals survived the infection, while all infected, untreated mice died. When treatment was begun one hour or one day after challenge, 70-90% of mice survived. Quantitation of infectious virus and viral RNA in samples of serum, liver and spleen collected on days 2 and 5 postinfection showed a trend toward lower titers in treated than control mice, with a significant decrease in liver titers on day 2. Our findings provide further evidence of the potential of natural lectins as therapeutic agents for viral infections. Published by Elsevier B.V.
-
Bukh, Jens; Meuleman, Philip; Tellier, Raymond; Engle, Ronald E.; Feinstone, Stephen M.; Eder, Gerald; Satterfield, William C.; Govindarajan, Sugantha; Krawczynski, Krzysztof; Miller, Roger H.; Leroux-Roels, Geert; Purcell, Robert H.
2010-01-01
Chimpanzees represent the only animal model for studies of the natural history of hepatitis C virus (HCV). To generate virus stocks of important HCV variants, we infected chimpanzees with HCV strains of genotypes 1–6 and determined the infectivity titer of acute-phase plasma pools in additional animals. The courses of first- and second-passage infections were similar, with early appearance of viremia, HCV RNA titers of >104.7 IU/mL, and development of acute hepatitis; the chronicity rate was 56%. The challenge pools had titers of 103–105 chimpanzee infectious doses/mL. Human liver–chimeric mice developed high-titer infections after inoculation with the challenge viruses of genotypes 1–6. Inoculation studies with different doses of the genotype 1b pool suggested that a relatively high virus dose is required to consistently infect chimeric mice. The challenge pools represent a unique resource for studies of HCV molecular virology and for studies of pathogenesis, protective immunity, and vaccine efficacy in vivo. PMID:20353362
-
Chen, Weizao; Liu, Mingqiu; Jiao, Ye; Yan, Weiyao; Wei, Xuefeng; Chen, Jiulian; Fei, Liang; Liu, Yang; Zuo, Xiaoping; Yang, Fugui; Lu, Yonggan; Zheng, Zhaoxin
2006-04-01
Foot-and-mouth disease virus (FMDV) infection is responsible for the heavy economic losses in stockbreeding each year. Because of the limited effectiveness of existing vaccines and antiviral drugs, the development of new strategies is needed. RNA interference (RNAi) is an effective means of suppressing virus replication in vitro. Here we demonstrate that treatment with recombinant, replication-defective human adenovirus type 5 (Ad5) expressing short-hairpin RNAs (shRNAs) directed against either structural protein 1D (Ad5-NT21) or polymerase 3D (Ad5-POL) of FMDV totally protects swine IBRS-2 cells from homologous FMDV infection, whereas only Ad5-POL inhibits heterologous FMDV replication. Moreover, delivery of these shRNAs significantly reduces the susceptibility of guinea pigs and swine to FMDV infection. Three of five guinea pigs inoculated with 10(6) PFU of Ad5-POL and challenged 24 h later with 50 50% infectious doses (ID50) of homologous virus were protected from the major clinical manifestation of disease: the appearance of vesicles on the feet. Two of three swine inoculated with an Ad5-NT21-Ad5-POL mixture containing 2 x 10(9) PFU each and challenged 24 h later with 100 ID50 of homologous virus were protected from the major clinical disease, but treatment with a higher dose of adenovirus mixture cannot promote protection of animals. The inhibition was rapid and specific because treatment with a control adenovirus construct (Ad5-LacZ) expressing Escherichia coli galactosidase-specific shRNA showed no marked antiviral activity. Our data highlight the in vivo potential of RNAi technology in the case of FMD.
-
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kaur, Amitinder; Sanford, Hannah B.; Garry, Deirdre
2007-01-20
The immunogenicity and protective capacity of replication-defective herpes simplex virus (HSV) vector-based vaccines were examined in rhesus macaques. Three macaques were inoculated with recombinant HSV vectors expressing Gag, Env, and a Tat-Rev-Nef fusion protein of simian immunodeficiency virus (SIV). Three other macaques were primed with recombinant DNA vectors expressing Gag, Env, and a Pol-Tat-Nef-Vif fusion protein prior to boosting with the HSV vectors. Robust anti-Gag and anti-Env cellular responses were detected in all six macaques. Following intravenous challenge with wild-type, cloned SIV239, peak and 12-week plasma viremia levels were significantly lower in vaccinated compared to control macaques. Plasma SIV RNAmore » in vaccinated macaques was inversely correlated with anti-Rev ELISPOT responses on the day of challenge (P value < 0.05), anti-Tat ELISPOT responses at 2 weeks post challenge (P value < 0.05) and peak neutralizing antibody titers pre-challenge (P value 0.06). These findings support continued study of recombinant herpesviruses as a vaccine approach for AIDS.« less
-
Brockmeier, Susan L; Loving, Crystal L; Eberle, Kirsten C; Hau, Samantha J; Buckley, Alexandra; Van Geelen, Albert; Montiel, Nestor A; Nicholson, Tracy; Lager, Kelly M
2017-12-01
Type I interferons, such as interferon alpha (IFN-α), contribute to innate antiviral immunity by promoting production of antiviral mediators and are also involved in promoting an adaptive immune response. Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most devastating and costly viruses to the swine industry world-wide and has been shown to induce a meager IFN-α response. Previously we administered porcine IFN-α using a replication-defective adenovirus vector (Ad5-IFN-α) at the time of challenge with virulent PRRSV and demonstrated an increase in the number of virus-specific IFNγ secreting cells, indicating that the presence of IFN-α at the time of infection can alter the adaptive immune responses to PRRSV. In the current experiment, we explored the use of IFN-α as an adjuvant administered with live-attenuated PRRSV vaccine as a method to enhance immune response to the vaccine. Unlike the previous studies with fully virulent virus, one injection of the Ad5-IFN-α abolished replication of the vaccine virus and as a result there was no detectible adaptive immune response. Although IFN-α did not have the desired adjuvant effect, the results further highlight the use of IFN-α as a treatment for PRRSV infection. Published by Elsevier B.V.
-
Frey, Tiffany R; Forsyth, Katherine S; Sheehan, Maura M; De Haven, Brian C; Pevarnik, Julia G; Hand, Erin S; Pizzorno, Marie C; Eisenlohr, Laurence C; Hersperger, Adam R
2018-05-01
All known orthopoxviruses, including ectromelia virus (ECTV), contain a gene in the E3L family. The protein product of this gene, E3, is a double-stranded RNA-binding protein. It can impact host range and is used by orthopoxviruses to combat cellular defense pathways, such as PKR and RNase L. In this work, we constructed an ECTV mutant with a targeted disruption of the E3L open reading frame (ECTVΔE3L). Infection with this virus resulted in an abortive replication cycle in all cell lines tested. We detected limited transcription of late genes but no significant translation of these mRNAs. Notably, the replication defects of ECTVΔE3L were rescued in human and mouse cells lacking PKR. ECTVΔE3L was nonpathogenic in BALB/c mice, a strain susceptible to lethal mousepox disease. However, infection with ECTVΔE3L induced protective immunity upon subsequent challenge with wild-type virus. In summary, E3L is an essential gene for ECTV. Copyright © 2018 Elsevier Inc. All rights reserved.
-
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
-
Promotion of Hendra Virus Replication by MicroRNA 146a
Marsh, Glenn A.; Jenkins, Kristie A.; Gantier, Michael P.; Tizard, Mark L.; Middleton, Deborah; Lowenthal, John W.; Haining, Jessica; Izzard, Leonard; Gough, Tamara J.; Deffrasnes, Celine; Stambas, John; Robinson, Rachel; Heine, Hans G.; Pallister, Jackie A.; Foord, Adam J.; Bean, Andrew G.; Wang, Lin-Fa
2013-01-01
Hendra virus is a highly pathogenic zoonotic paramyxovirus in the genus Henipavirus. Thirty-nine outbreaks of Hendra virus have been reported since its initial identification in Queensland, Australia, resulting in seven human infections and four fatalities. Little is known about cellular host factors impacting Hendra virus replication. In this work, we demonstrate that Hendra virus makes use of a microRNA (miRNA) designated miR-146a, an NF-κB-responsive miRNA upregulated by several innate immune ligands, to favor its replication. miR-146a is elevated in the blood of ferrets and horses infected with Hendra virus and is upregulated by Hendra virus in human cells in vitro. Blocking miR-146a reduces Hendra virus replication in vitro, suggesting a role for this miRNA in Hendra virus replication. In silico analysis of miR-146a targets identified ring finger protein (RNF)11, a member of the A20 ubiquitin editing complex that negatively regulates NF-κB activity, as a novel component of Hendra virus replication. RNA interference-mediated silencing of RNF11 promotes Hendra virus replication in vitro, suggesting that increased NF-κB activity aids Hendra virus replication. Furthermore, overexpression of the IκB superrepressor inhibits Hendra virus replication. These studies are the first to demonstrate a host miRNA response to Hendra virus infection and suggest an important role for host miRNAs in Hendra virus disease. PMID:23345523
-
Krug, Peter W; Holinka, Lauren G; O'Donnell, Vivian; Reese, Bo; Sanford, Brenton; Fernandez-Sainz, Ignacio; Gladue, Douglas P; Arzt, Jonathan; Rodriguez, Luis; Risatti, Guillermo R; Borca, Manuel V
2015-02-01
African swine fever virus (ASFV) causes a contagious and often lethal disease of feral and domestic swine. Experimental vaccines derived from naturally occurring, genetically modified, or cell culture-adapted ASFV have been evaluated, but no commercial vaccine is available to control African swine fever (ASF). We report here the genotypic and phenotypic analysis of viruses obtained at different passages during the process of adaptation of a virulent ASFV field isolate from the Republic of Georgia (ASFV-G) to grow in cultured cell lines. ASFV-G was successively passaged 110 times in Vero cells. Viruses obtained at passages 30, 60, 80, and 110 were evaluated in vitro for the ability to replicate in Vero cells and primary swine macrophages cultures and in vivo for assessing virulence in swine. Replication of ASFV-G in Vero cells increased with successive passages, corresponding to a decreased replication in primary swine macrophages cultures. In vivo, progressive loss of virus virulence was observed with increased passages in Vero cells, and complete attenuation of ASFV-G was observed at passage 110. Infection of swine with the fully attenuated virus did not confer protection against challenge with virulent parental ASFV-G. Full-length sequence analysis of each of these viruses revealed significant deletions that gradually accumulated in specific areas at the right and left variable ends of the genome. Mutations that result in amino acid substitutions and frameshift mutations were also observed, though in a rather limited number of genes. The potential importance of these genetic changes in virus adaptation/attenuation is discussed. The main problem in controlling ASF is the lack of vaccines. Attempts to produce vaccines by adaptation of ASFV to cultured cell lines have been made. These attempts led to the production of attenuated viruses that conferred only homologous protection. Specifics regarding adaptation of these isolates to cell cultures have been insufficiently described. Details like the numbers of passages required to obtain attenuated viruses, genetic modifications introduced into the virus genomes along passages, and the extent of attenuation and induced protective efficacy are not readily available. In this study, we assessed the changes that lead to decreased growth in swine macrophages and to attenuation in swine. Loss of virulence, probably associated with limited replication in vivo, may lead to the lack of protective immunity in swine observed after challenge. This report provides valuable information that can be used to further the understanding of ASFV gene function, virus attenuation, and protection against infection. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
-
Krug, Peter W.; Holinka, Lauren G.; O'Donnell, Vivian; Reese, Bo; Sanford, Brenton; Fernandez-Sainz, Ignacio; Gladue, Douglas P.; Arzt, Jonathan; Rodriguez, Luis; Risatti, Guillermo R.
2014-01-01
ABSTRACT African swine fever virus (ASFV) causes a contagious and often lethal disease of feral and domestic swine. Experimental vaccines derived from naturally occurring, genetically modified, or cell culture-adapted ASFV have been evaluated, but no commercial vaccine is available to control African swine fever (ASF). We report here the genotypic and phenotypic analysis of viruses obtained at different passages during the process of adaptation of a virulent ASFV field isolate from the Republic of Georgia (ASFV-G) to grow in cultured cell lines. ASFV-G was successively passaged 110 times in Vero cells. Viruses obtained at passages 30, 60, 80, and 110 were evaluated in vitro for the ability to replicate in Vero cells and primary swine macrophages cultures and in vivo for assessing virulence in swine. Replication of ASFV-G in Vero cells increased with successive passages, corresponding to a decreased replication in primary swine macrophages cultures. In vivo, progressive loss of virus virulence was observed with increased passages in Vero cells, and complete attenuation of ASFV-G was observed at passage 110. Infection of swine with the fully attenuated virus did not confer protection against challenge with virulent parental ASFV-G. Full-length sequence analysis of each of these viruses revealed significant deletions that gradually accumulated in specific areas at the right and left variable ends of the genome. Mutations that result in amino acid substitutions and frameshift mutations were also observed, though in a rather limited number of genes. The potential importance of these genetic changes in virus adaptation/attenuation is discussed. IMPORTANCE The main problem in controlling ASF is the lack of vaccines. Attempts to produce vaccines by adaptation of ASFV to cultured cell lines have been made. These attempts led to the production of attenuated viruses that conferred only homologous protection. Specifics regarding adaptation of these isolates to cell cultures have been insufficiently described. Details like the numbers of passages required to obtain attenuated viruses, genetic modifications introduced into the virus genomes along passages, and the extent of attenuation and induced protective efficacy are not readily available. In this study, we assessed the changes that lead to decreased growth in swine macrophages and to attenuation in swine. Loss of virulence, probably associated with limited replication in vivo, may lead to the lack of protective immunity in swine observed after challenge. This report provides valuable information that can be used to further the understanding of ASFV gene function, virus attenuation, and protection against infection. PMID:25505073
-
Vaginal Exposure to Zika Virus during Pregnancy Leads to Fetal Brain Infection.
Yockey, Laura J; Varela, Luis; Rakib, Tasfia; Khoury-Hanold, William; Fink, Susan L; Stutz, Bernardo; Szigeti-Buck, Klara; Van den Pol, Anthony; Lindenbach, Brett D; Horvath, Tamas L; Iwasaki, Akiko
2016-08-25
Zika virus (ZIKV) can be transmitted sexually between humans. However, it is unknown whether ZIKV replicates in the vagina and impacts the unborn fetus. Here, we establish a mouse model of vaginal ZIKV infection and demonstrate that, unlike other routes, ZIKV replicates within the genital mucosa even in wild-type (WT) mice. Mice lacking RNA sensors or transcription factors IRF3 and IRF7 resulted in higher levels of local viral replication. Furthermore, mice lacking the type I interferon (IFN) receptor (IFNAR) became viremic and died of infection after a high-dose vaginal ZIKV challenge. Notably, vaginal infection of pregnant dams during early pregnancy led to fetal growth restriction and infection of the fetal brain in WT mice. This was exacerbated in mice deficient in IFN pathways, leading to abortion. Our study highlights the vaginal tract as a highly susceptible site of ZIKV replication and illustrates the dire disease consequences during pregnancy. Copyright © 2016 Elsevier Inc. All rights reserved.
-
Bukreyev, Alexander A; Dinapoli, Joshua M; Yang, Lijuan; Murphy, Brian R; Collins, Peter L
2010-04-10
We previously used human parainfluenza virus type 3 (HPIV3) as a vector to express the Ebola virus (EBOV) GP glycoprotein. The resulting HPIV3/EboGP vaccine was immunogenic and protective against EBOV challenge in a non-human primate model. However, it remained unclear whether the vaccine would be effective in adults due to preexisting immunity to HPIV3. Here, the immunogenicity of HPIV3/EboGP was compared in HPIV3-naive and HPIV3-immune Rhesus monkeys. After a single dose of HPIV3/EboGP, the titers of EBOV-specific serum ELISA or neutralization antibodies were substantially less in HPIV3-immune animals compared to HPIV3-naive animals. However, after two doses, which were previously determined to be required for complete protection against EBOV challenge, the antibody titers were indistinguishable between the two groups. The vaccine virus appeared to replicate, at a reduced level, in the respiratory tract despite the preexisting immunity. This may reflect the known ability of HPIV3 to re-infect and may also reflect the presence of EBOV GP in the vector virion, which confers resistance to neutralization in vitro by HPIV3-specific antibodies. These data suggest that HPIV3/EboGP will be immunogenic in adults as well as children. Published by Elsevier Inc.
-
Broadbent, Andrew J.; Santos, Celia P.; Anafu, Amanda; Wimmer, Eckard; Mueller, Steffen; Subbarao, Kanta
2015-01-01
Codon-pair bias de-optimization (CPBD) of viruses involves re-writing viral genes using statistically underrepresented codon pairs, without any changes to the amino acid sequence or codon usage. Previously, this technology has been used to attenuate the influenza A/Puerto Rico/8/34 (H1N1) virus. The de-optimized virus was immunogenic and protected inbred mice from challenge. In order to assess whether CPBD could be used to produce a live vaccine against a clinically relevant influenza virus, we generated an influenza A/California/07/2009 pandemic H1N1 (2009 pH1N1) virus with de-optimized HA and NA gene segments (2009 pH1N1-(HA+NA)Min), and evaluated viral replication and protein expression in MDCK cells, and attenuation, immunogenicity, and efficacy in outbred ferrets. The 2009 pH1N1-(HA+NA)Min virus grew to a similar titer as the 2009 pH1N1 wild type (wt) virus in MDCK cells (~106 TCID50/ml), despite reduced HA and NA protein expression on western blot. In ferrets, intranasal inoculation of 2009 pH1N1-(HA+NA)Min virus at doses ranging from 103 to 105 TCID50 led to seroconversion in all animals and protection from challenge with the 2009 pH1N1 wt virus 28 days later. The 2009 pH1N1-(HA+NA)Min virus did not cause clinical illness in ferrets, but replicated to a similar titer as the wt virus in the upper and lower respiratory tract, suggesting that de-optimization of additional gene segments may be warranted for improved attenuation. Taken together, our data demonstrate the potential of using CPBD technology for the development of a live influenza virus vaccine if the level of attenuation is optimized. PMID:26655630
-
Cathepsin B & L are not required for ebola virus replication.
Marzi, Andrea; Reinheckel, Thomas; Feldmann, Heinz
2012-01-01
Ebola virus (EBOV), family Filoviridae, emerged in 1976 on the African continent. Since then it caused several outbreaks of viral hemorrhagic fever in humans with case fatality rates up to 90% and remains a serious Public Health concern and biothreat pathogen. The most pathogenic and best-studied species is Zaire ebolavirus (ZEBOV). EBOV encodes one viral surface glycoprotein (GP), which is essential for replication, a determinant of pathogenicity and an important immunogen. GP mediates viral entry through interaction with cellular surface molecules, which results in the uptake of virus particles via macropinocytosis. Later in this pathway endosomal acidification activates the cysteine proteases Cathepsin B and L (CatB, CatL), which have been shown to cleave ZEBOV-GP leading to subsequent exposure of the putative receptor-binding and fusion domain and productive infection. We studied the effect of CatB and CatL on in vitro and in vivo replication of EBOV. Similar to previous findings, our results show an effect of CatB, but not CatL, on ZEBOV entry into cultured cells. Interestingly, cell entry by other EBOV species (Bundibugyo, Côte d'Ivoire, Reston and Sudan ebolavirus) was independent of CatB or CatL as was EBOV replication in general. To investigate whether CatB and CatL have a role in vivo during infection, we utilized the mouse model for ZEBOV. Wild-type (control), catB(-/-) and catL(-/-) mice were equally susceptible to lethal challenge with mouse-adapted ZEBOV with no difference in virus replication and time to death. In conclusion, our results show that CatB and CatL activity is not required for EBOV replication. Furthermore, EBOV glycoprotein cleavage seems to be mediated by an array of proteases making targeted therapeutic approaches difficult.
-
Franzoso, Francesca D.; Seyffert, Michael; Vogel, Rebecca; Yakimovich, Artur; de Andrade Pereira, Bruna; Meier, Anita F.; Sutter, Sereina O.; Tobler, Kurt; Vogt, Bernd; Greber, Urs F.; Büning, Hildegard; Ackermann, Mathias
2017-01-01
ABSTRACT Adeno-associated virus 2 (AAV2) depends on the simultaneous presence of a helper virus such as herpes simplex virus 1 (HSV-1) for productive replication. At the same time, AAV2 efficiently blocks the replication of HSV-1, which would eventually limit its own replication by diminishing the helper virus reservoir. This discrepancy begs the question of how AAV2 and HSV-1 can coexist in a cell population. Here we show that in coinfected cultures, AAV2 DNA replication takes place almost exclusively in S/G2-phase cells, while HSV-1 DNA replication is restricted to G1 phase. Live microscopy revealed that not only wild-type AAV2 (wtAAV2) replication but also reporter gene expression from both single-stranded and double-stranded (self-complementary) recombinant AAV2 vectors preferentially occurs in S/G2-phase cells, suggesting that the preference for S/G2 phase is independent of the nature of the viral genome. Interestingly, however, a substantial proportion of S/G2-phase cells transduced by the double-stranded but not the single-stranded recombinant AAV2 vectors progressed through mitosis in the absence of the helper virus. We conclude that cell cycle-dependent AAV2 rep expression facilitates cell cycle-dependent AAV2 DNA replication and inhibits HSV-1 DNA replication. This may limit competition for cellular and viral helper factors and, hence, creates a biological niche for either virus to replicate. IMPORTANCE Adeno-associated virus 2 (AAV2) differs from most other viruses, as it requires not only a host cell for replication but also a helper virus such as an adenovirus or a herpesvirus. This situation inevitably leads to competition for cellular resources. AAV2 has been shown to efficiently inhibit the replication of helper viruses. Here we present a new facet of the interaction between AAV2 and one of its helper viruses, herpes simplex virus 1 (HSV-1). We observed that AAV2 rep gene expression is cell cycle dependent and gives rise to distinct time-controlled windows for HSV-1 replication. High Rep protein levels in S/G2 phase support AAV2 replication and inhibit HSV-1 replication. Conversely, low Rep protein levels in G1 phase permit HSV-1 replication but are insufficient for AAV2 replication. This allows both viruses to productively replicate in distinct sets of dividing cells. PMID:28515305
-
Nara, P L; Smit, L; Dunlop, N; Hatch, W; Merges, M; Waters, D; Kelliher, J; Gallo, R C; Fischinger, P J; Goudsmit, J
1990-01-01
Emergence in two chimpanzees of human immunodeficiency virus type 1 (HIV-1) IIIB variants resistant to neutralization by the preexisting antibody is described. Viruses isolated from the HIV-1 IIIB gp120-vaccinated and -challenged animal were more resistant to neutralization by the chimpanzee's own serum than viruses isolated from the naive infected animal, indicating immune pressure as the selective mechanism. However, all reisolated viruses were 16- to 256-fold more neutralization resistant than the inoculum virus to antibodies binding to the third variable domain (V3) of the HIV-1 external envelope. Early chimpanzee serum samples that neutralized the inoculum strain but not the reisolated viruses were found to bind an HIV-1 IIIB common nonapeptide (IQRGPGRAF) derived from the gp120 isolate-specific V3 domain shown to induce isolate-specific neutralization in other animals. Amplification of the V3 coding sequence by polymerase chain reaction and subsequent sequence analysis of the neutralization-resistant variants obtained from in vivo-infected animals indicated that early resistance to neutralization by an HIV-1 IIIB monoclonal antibody (0.5 beta) was conferred by changes outside the direct binding site for the selective neutralizing antibody. The reisolated neutralization-resistant isolates consisted of the lower-replication-competent virus subpopulations of the HIV-1 IIIB stock, as confirmed by biological and sequence analyses. In vitro passage of the HIV-1 IIIB stock through chimpanzee and human peripheral blood mononuclear cell cultures void of HIV-specific antibody resulted in homogenic amplification of the more-replication-competent subpopulation preexisting in the original viral stock, suggesting a role for the immune system in suppressing the more-replication-competent viruses. Images PMID:2370681
-
Characterization of a Human H5N1 Influenza A Virus Isolated in 2003
Shinya, Kyoko; Hatta, Masato; Yamada, Shinya; Takada, Ayato; Watanabe, Shinji; Halfmann, Peter; Horimoto, Taisuke; Neumann, Gabriele; Kim, Jin Hyun; Lim, Wilina; Guan, Yi; Peiris, Malik; Kiso, Makoto; Suzuki, Takashi; Suzuki, Yasuo; Kawaoka, Yoshihiro
2005-01-01
In 2003, H5N1 avian influenza virus infections were diagnosed in two Hong Kong residents who had visited the Fujian province in mainland China, affording us the opportunity to characterize one of the viral isolates, A/Hong Kong/213/03 (HK213; H5N1). In contrast to H5N1 viruses isolated from humans during the 1997 outbreak in Hong Kong, HK213 retained several features of aquatic bird viruses, including the lack of a deletion in the neuraminidase stalk and the absence of additional oligosaccharide chains at the globular head of the hemagglutinin molecule. It demonstrated weak pathogenicity in mice and ferrets but caused lethal infection in chickens. The original isolate failed to produce disease in ducks but became more pathogenic after five passages. Taken together, these findings portray the HK213 isolate as an aquatic avian influenza A virus without the molecular changes associated with the replication of H5N1 avian viruses in land-based poultry such as chickens. This case challenges the view that adaptation to land-based poultry is a prerequisite for the replication of aquatic avian influenza A viruses in humans. PMID:16014953
-
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
-
Swenson, Dana L; Warfield, Kelly L; Warren, Travis K; Lovejoy, Candace; Hassinger, Jed N; Ruthel, Gordon; Blouch, Robert E; Moulton, Hong M; Weller, Dwight D; Iversen, Patrick L; Bavari, Sina
2009-05-01
Phosphorodiamidate morpholino oligomers (PMOs) are uncharged nucleic acid-like molecules designed to inactivate the expression of specific genes via the antisense-based steric hindrance of mRNA translation. PMOs have been successful at knocking out viral gene expression and replication in the case of acute viral infections in animal models and have been well tolerated in human clinical trials. We propose that antisense PMOs represent a promising class of therapeutic agents that may be useful for combating filoviral infections. We have previously shown that mice treated with a PMO whose sequence is complementary to a region spanning the start codon of VP24 mRNA were protected against lethal Ebola virus challenge. In the present study, we report on the abilities of two additional VP24-specific PMOs to reduce the cell-free translation of a VP24 reporter, to inhibit the in vitro replication of Ebola virus, and to protect mice against lethal challenge when the PMOs are delivered prior to infection. Additionally, structure-activity relationship evaluations were conducted to assess the enhancement of antiviral efficacy associated with PMO chemical modifications that included conjugation with peptides of various lengths and compositions, positioning of conjugated peptides to either the 5' or the 3' terminus, and the conferring of charge modifications by the addition of piperazine moieties. Conjugation with arginine-rich peptides greatly enhanced the antiviral efficacy of VP24-specific PMOs in infected cells and mice during lethal Ebola virus challenge.
-
Brostoff, Terza; Pesavento, Patricia A.; Barker, Christopher M.; Kenney, Joan L.; Dietrich, Elizabeth A.; Duggal, Nisha K.; Bosco-Lauth, Angela M.; Brault, Aaron C.
2017-01-01
West Nile virus (WNV) is an important agent of human encephalitis that has quickly become endemic across much of the United States since its identification in North America in 1999. While the majority (~75%) of infections are subclinical, neurologic disease can occur in a subset of cases, with outcomes including permanent neurologic damage and death. Currently, there are no WNV vaccines approved for use in humans. This study introduces a novel vaccine platform for WNV to reduce viral replication in the central nervous system while maintaining peripheral replication to elicit strong neutralizing antibody titers. Vaccine candidates were engineered to incorporate microRNA (miRNA) target sequences for a cognate miRNA expressed only in neurons, allowing the host miRNAs to target viral transcription through endogenous RNA silencing. To maintain stability, these targets were incorporated in multiple locations within the 3′-untranslated region, flanking sequences essential for viral replication without affecting the viral open reading frame. All candidates replicated comparably to wild type WNV in vitro within cells that did not express the cognate miRNA. Insertional control viruses were also capable of neuroinvasion and neurovirulence in vivo in CD-1 mice. Vaccine viruses were safe at all doses tested and did not demonstrate mutations associated with a reversion to virulence when serially passaged in mice. All vaccine constructs were protective from lethal challenge in mice, producing 93–100% protection at the highest dose tested. Overall, this is a safe and effective attenuation strategy with broad potential application for vaccine development. PMID:27637937
-
Brostoff, Terza; Pesavento, Patricia A; Barker, Christopher M; Kenney, Joan L; Dietrich, Elizabeth A; Duggal, Nisha K; Bosco-Lauth, Angela M; Brault, Aaron C
2016-10-17
West Nile virus (WNV) is an important agent of human encephalitis that has quickly become endemic across much of the United States since its identification in North America in 1999. While the majority (∼75%) of infections are subclinical, neurologic disease can occur in a subset of cases, with outcomes including permanent neurologic damage and death. Currently, there are no WNV vaccines approved for use in humans. This study introduces a novel vaccine platform for WNV to reduce viral replication in the central nervous system while maintaining peripheral replication to elicit strong neutralizing antibody titers. Vaccine candidates were engineered to incorporate microRNA (miRNA) target sequences for a cognate miRNA expressed only in neurons, allowing the host miRNAs to target viral transcription through endogenous RNA silencing. To maintain stability, these targets were incorporated in multiple locations within the 3'-untranslated region, flanking sequences essential for viral replication without affecting the viral open reading frame. All candidates replicated comparably to wild type WNV in vitro within cells that did not express the cognate miRNA. Insertional control viruses were also capable of neuroinvasion and neurovirulence in vivo in CD-1 mice. Vaccine viruses were safe at all doses tested and did not demonstrate mutations associated with a reversion to virulence when serially passaged in mice. All vaccine constructs were protective from lethal challenge in mice, producing 93-100% protection at the highest dose tested. Overall, this is a safe and effective attenuation strategy with broad potential application for vaccine development. Published by Elsevier Ltd.
-
Tian, Debin; Sooryanarain, Harini; Matzinger, Shannon R; Gauger, Phil C; Karuppannan, Anbu K; Elankumaran, Subbiah; Opriessnig, Tanja; Meng, Xiang-Jin
2017-12-01
Porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2) and swine influenza virus (SIV) are three of the most economically important swine pathogens, causing immense economic losses to the global swine industry. Monovalent commercial vaccines against each of the three viruses are routinely used in pig farms worldwide. A trivalent vaccine against all three pathogens would greatly simplify the vaccination programme and reduce the financial burden to the swine industry. In this study, by using an attenuated strain of PRRSV (strain DS722) as a live virus vector, we generated a multi-component vaccine virus, DS722-SIV-PCV2, which expresses the protective antigens from SIV and PCV2. The DS722-SIV-PCV2 trivalent vaccine virus replicates well, and expresses PCV2 capsid and SIV HA proteins in vitro. A subsequent vaccination and challenge study in 48 pigs revealed that the DS722-SIV-PCV2-vaccinated pigs had significantly reduced lung lesions and viral RNA loads when challenged with PRRSV. Upon challenge with PCV2, the vaccinated pigs had partially reduced lymphoid lesions and viral DNA loads, and when challenged with SIV the vaccinated pigs had significantly reduced acute respiratory sign scores. The results from this study demonstrate the potential of DS722-SIV-PCV2 as a candidate trivalent vaccine, and also shed light on exploring PRRSV as a potential live virus vaccine vector.
-
Analysis of BZLF1 mRNA detection in saliva as a marker for active replication of Epstein-Barr virus.
Fagin, Ursula; Nerbas, Linda; Vogl, Bastian; Jabs, Wolfram J
2017-06-01
Monitoring replicative Epstein-Barr virus (EBV) infection still remains a challenge in modern laboratory routine. The immediate-early protein BZLF1 mediates the switch between latent and replicate forms of EBV infection. The aim of this study was to analyze the feasibility of BZLF1 mRNA detection in saliva as a marker for active replication of the virus. Various specimens (saliva, plasma, PBMC) from 17 patients with EBV-induced infectious mononucleosis (IM) and 4 control patients were examined for expression of viral BZLF1 mRNA by means of real-time PCR. BZLF1 expression was correlated to the amount of viral DNA in either compartment. Digestion of plasma and saliva samples with DNase I allowed distinguishing between encapsidated and naked viral DNA. BZLF1 transcripts were found in all different types of specimens in varying frequencies. BZLF1 expression in saliva, PBMC, and plasma correlated with viral load in each compartment. Interestingly, those patients with detectable BZLF1 expression in saliva had a more severe course of infection with longer duration of hospitalization. In conclusion, this study demonstrates the feasibility of BZLF1 mRNA detection in saliva specimens during replicative EBV infection. Its significance for the diagnosis of reactivated EBV infection, particularly under immunosuppression, has to be elucidated in further studies. Copyright © 2017 Elsevier B.V. All rights reserved.
-
Work, Thierry M; Dagenais, Julie; Weatherby, Tina M; Balazs, George H; Ackermann, Mathias
2017-09-01
Fibropapillomatosis (FP) is a tumor disease of marine turtles associated with chelonid herpesvirus 5 (ChHV5), which has historically been refractory to growth in tissue culture. Here we show, for the first time, de novo formation of ChHV5-positive intranuclear inclusions in cultured green turtle cells, which is indicative of active lytic replication of the virus. The minimal requirements to achieve lytic replication in cultured cells included (i) either in vitro cultures of ChHV5-positive tumor biopsy specimens (plugs) or organotypic cultures (rafts) consisting of ChHV5-positive turtle fibroblasts in collagen rafts seeded with turtle keratinocytes and (ii) keratinocyte maturation induced by raising raft or biopsy cultures to the air-liquid interface. Virus growth was confirmed by detailed electron microscopic studies that revealed intranuclear sun-shaped capsid factories, tubules, various stages of capsid formation, nuclear export by budding into the perinuclear space, tegument formation, and envelopment to complete de novo virus production. Membrane synthesis was also observed as a sign of active viral replication. Interestingly, cytoplasmic particles became associated with keratin filaments, a feature not seen in conventional monolayer cell cultures, in which most studies of herpesvirus replication have been performed. Our findings draw a rich and realistic picture of ChHV5 replication in cells derived from its natural host and may be crucial not only to better understand ChHV5 circulation but also to eventually complete Koch's postulates for FP. Moreover, the principles described here may serve as a model for culture of other viruses that are resistant to replication in conventional cell culture. IMPORTANCE A major challenge in virology is the study of viruses that cannot be grown in the laboratory. One example is chelonid herpesvirus 5 (ChHV5), which is associated with fibropapillomatosis, a globally distributed, debilitating, and fatal tumor disease of endangered marine turtles. Pathological examination shows that ChHV5 is shed in skin. Here we show that ChHV5 will grow in vitro if we replicate the complex three-dimensional structure of turtle skin. Moreover, lytic virus growth requires a close interplay between fibroblasts and keratinocytes. Finally, the morphogenesis of herpesviral growth in three-dimensional cultures reveals a far richer, and likely more realistic, array of capsid morphologies than that encountered in traditional monolayer cell cultures. Our findings have applications to other viruses, including those of humans. Copyright © 2017 American Society for Microbiology.
-
Baz, Mariana; Paskel, Myeisha; Matsuoka, Yumiko; Zengel, James; Cheng, Xing; Jin, Hong
2013-01-01
Since it is difficult to predict which influenza virus subtype will cause an influenza pandemic, it is important to prepare influenza virus vaccines against different subtypes and evaluate the safety and immunogenicity of candidate vaccines in preclinical and clinical studies prior to a pandemic. In addition to infecting humans, H3 influenza viruses commonly infect pigs, horses, and avian species. We selected 11 swine, equine, and avian H3 influenza viruses and evaluated their kinetics of replication and ability to induce a broadly cross-reactive antibody response in mice and ferrets. The swine and equine viruses replicated well in the upper respiratory tract of mice. With the exception of one avian virus that replicated poorly in the lower respiratory tract, all of the viruses replicated in mouse lungs. In ferrets, all of the viruses replicated well in the upper respiratory tract, but the equine viruses replicated poorly in the lungs. Extrapulmonary spread was not observed in either mice or ferrets. No single virus elicited antibodies that cross-reacted with viruses from all three animal sources. Avian and equine H3 viruses elicited broadly cross-reactive antibodies against heterologous viruses isolated from the same or other species, but the swine viruses did not. We selected an equine and an avian H3 influenza virus for further development as vaccines. PMID:23576512
-
Human DDX3 protein is a valuable target to develop broad spectrum antiviral agents
Brai, Annalaura; Fazi, Roberta; Tintori, Cristina; Zamperini, Claudio; Bugli, Francesca; Sanguinetti, Maurizio; Stigliano, Egidio; Esté, José; Badia, Roger; Franco, Sandra; Martinez, Javier P.; Meyerhans, Andreas; Saladini, Francesco; Zazzi, Maurizio; Garbelli, Anna; Botta, Maurizio
2016-01-01
Targeting a host factor essential for the replication of different viruses but not for the cells offers a higher genetic barrier to the development of resistance, may simplify therapy regimens for coinfections, and facilitates management of emerging viral diseases. DEAD-box polypeptide 3 (DDX3) is a human host factor required for the replication of several DNA and RNA viruses, including some of the most challenging human pathogens currently circulating, such as HIV-1, Hepatitis C virus, Dengue virus, and West Nile virus. Herein, we showed for the first time, to our knowledge, that the inhibition of DDX3 by a small molecule could be successfully exploited for the development of a broad spectrum antiviral agent. In addition to the multiple antiviral activities, hit compound 16d retained full activity against drug-resistant HIV-1 strains in the absence of cellular toxicity. Pharmacokinetics and toxicity studies in rats confirmed a good safety profile and bioavailability of 16d. Thus, DDX3 is here validated as a valuable therapeutic target. PMID:27118832
-
Sanford, B; Holinka, L G; O'Donnell, V; Krug, P W; Carlson, J; Alfano, M; Carrillo, C; Wu, Ping; Lowe, Andre; Risatti, G R; Gladue, D P; Borca, M V
2016-02-02
African swine fever virus (ASFV) is the etiological agent of a contagious and often lethal viral disease of domestic pigs. There are no vaccines to control Africa swine fever (ASF). Experimental vaccines have been developed using genetically modified live attenuated ASFVs obtained by specifically deleting virus genes involved in virulence, including the thymidine kinase (TK) gene. TK has been shown to be involved in the virulence of several viruses, including ASFV. Here we report the construction of a recombinant virus (ASFV-G/V-ΔTK) obtained by deleting the TK gene in a virulent strain of ASFV Georgia adapted to replicate in Vero cells (ASFV-G/VP30). ASFV-G/P-ΔTK demonstrated decreased replication both in primary swine macrophage cell cultures and in Vero cells compared with ASFV-G/VP30. In vivo, intramuscular administration of up to 10(6) TCID50 of ASFV-G/V-ΔTK does not result in ASF disease. However, these animals are not protected when challenged with the virulent parental Georgia strain. Published by Elsevier B.V.
-
Winstone, Nicola; Wilson, Aaron J.; Morrow, Gavin; Boggiano, Cesar; Chiuchiolo, Maria J.; Lopez, Mary; Kemelman, Marina; Ginsberg, Arielle A.; Mullen, Karl; Coleman, John W.; Wu, Chih-Da; Narpala, Sandeep; Ouellette, Ian; Dean, Hansi J.; Lin, Feng; Sardesai, Niranjan Y.; Cassamasa, Holly; McBride, Dawn; Felber, Barbara K.; Pavlakis, George N.; Schultz, Alan; Hudgens, Michael G.; King, C. Richter; Zamb, Timothy J.; Parks, Christopher L.; McDermott, Adrian B.
2011-01-01
DNA priming has previously been shown to elicit augmented immune responses when administered by electroporation (EP) or codelivered with a plasmid encoding interleukin-12 (pIL-12). We hypothesized that the efficacy of a DNA prime and recombinant adenovirus 5 boost vaccination regimen (DNA/rAd5) would be improved when incorporating these vaccination strategies into the DNA priming phase, as determined by pathogenic simian immunodeficiency virus SIVmac239 challenge outcome. The whole SIVmac239 proteome was delivered in 5 separate DNA plasmids (pDNA-SIV) by EP with or without pIL-12, followed by boosting 4 months later with corresponding rAd5-SIV vaccine vectors. Remarkably, after repeated low-dose SIVmac239 mucosal challenge, we demonstrate 2.6 and 4.4 log reductions of the median SIV peak and set point viral loads in rhesus macaques (RMs) that received pDNA-SIV by EP with pIL-12 compared to the median peak and set point viral loads in mock-immunized controls (P < 0.01). In 5 out of 6 infected RMs, strong suppression of viremia was observed, with intermittent “blips” in virus replication. In 2 RMs, we could not detect the presence of SIV RNA in tissue and lymph nodes, even after 13 viral challenges. RMs immunized without pIL-12 demonstrated a typical maximum of 1.5 log reduction in virus load. There was no significant difference in the overall magnitude of SIV-specific antibodies or CD8 T-cell responses between groups; however, pDNA delivery by EP with pIL-12 induced a greater magnitude of SIV-specific CD4 T cells that produced multiple cytokines. This vaccine strategy is relevant for existing vaccine candidates entering clinical evaluation, and this model may provide insights into control of retrovirus replication. PMID:21734035
-
Wang, Shuchao; Sun, Chenglong; Zhang, Shoufeng; Zhang, Xiaozhuo; Liu, Ye; Wang, Ying; Zhang, Fei; Wu, Xianfu; Hu, Rongliang
2015-09-01
The rabies virus (RABV) glycoprotein (G) is responsible for inducing neutralizing antibodies against rabies virus. Development of recombinant vaccines using the G genes from attenuated strains rather than street viruses is a regular practice. In contrast to this scenario, we generated three human adenovirus type 5 recombinants using the G genes from the vaccine strains SRV9 and Flury-LEP, and the street RABV strain BD06 (nrAd5-SRV9-G, nrAd5-Flury-LEP-G, and nrAd5-BD06-G). These recombinants were non-replicative, but could grow up to ~10(8) TCID50/ml in helper HEK293AD cells. Expression of the G protein was verified by immunostaining, quantitative PCR and cytometry. Animal experiments revealed that immunization with nrAd5-BD06-G can induce a higher seroconversion rate, a higher neutralizing antibody level, and a longer survival time after rabies virus challenge in mice when compared with the other two recombinants. Moreover, the expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) was significantly higher in mice immunized with nrAd5-BD06-G, which might also contribute to the increased protection. These results show that the use of street RABV G for non-replicative systems may be an alternative for developing effective recombinant rabies vaccines.
-
Protease-deficient herpes simplex virus protects mice from lethal herpesvirus infection.
Hippenmeyer, P J; Rankin, A M; Luckow, V A; Neises, G R
1997-01-01
Null mutants and attenuated mutants of herpes simplex virus (HSV) have been shown to induce immunity against challenge from wild-type virus. Null viruses with a defect in late gene products would be expected to express more viral genes than viruses with defects in essential early gene products and thus induce a better immune response. Herpesviruses encode a late gene product (serine protease) that is autocatalytic and cleaves the capsid assembly protein during viral replication. To determine whether a virus with a mutation in this gene could induce immunity, we constructed a recombinant virus containing the gusA reporter gene in the protease domain of the HSV type 1 UL26 open reading frame (ORF). Consistent with previous results (M. Gao, L. Matusick-Kumar, W. Hurlburt, S. F. DiTusa, W. W. Newcomb, J. C. Brown, P. J. McCann, I. Deckman, and R. J. Colonno, J. Virol. 68:3702-3712, 1994), recombinant virus could be isolated only from helper cell lines expressing the product of the UL26 ORF. Mice inoculated with the recombinant virus were unaffected by doses of virus that were lethal to mice infected with wild-type virus. Mice which were previously inoculated with the recombinant virus were also protected by a subsequent challenge with wild-type virus in a dose-dependent manner. These results indicate that recombinant viruses lacking the protease gene are avirulent but render protection from subsequent challenge. PMID:8995617
-
Vesicular Egress of Non-Enveloped Lytic Parvoviruses Depends on Gelsolin Functioning
Bär, Séverine; Daeffler, Laurent; Rommelaere, Jean; Nüesch, Jürg P. F.
2008-01-01
The autonomous parvovirus Minute Virus of Mice (MVM) induces specific changes in the cytoskeleton filaments of infected permissive cells, causing in particular the degradation of actin fibers and the generation of “actin patches.” This is attributed to a virus-induced imbalance between the polymerization factor N-WASP (Wiscott-Aldrich syndrome protein) and gelsolin, a multifunctional protein cleaving actin filaments. Here, the focus is on the involvement of gelsolin in parvovirus propagation and virus-induced actin processing. Gelsolin activity was knocked-down, and consequences thereof were determined for virus replication and egress and for actin network integrity. Though not required for virus replication or progeny particle assembly, gelsolin was found to control MVM (and related H1-PV) transport from the nucleus to the cell periphery and release into the culture medium. Gelsolin-dependent actin degradation and progeny virus release were both controlled by (NS1)/CKIIα, a recently identified complex between a cellular protein kinase and a MVM non-structural protein. Furthermore, the export of newly synthesized virions through the cytoplasm appeared to be mediated by (virus-modified) lysomal/late endosomal vesicles. By showing that MVM release, like entry, is guided by the cytoskeleton and mediated by vesicles, these results challenge the current view that egress of non-enveloped lytic viruses is a passive process. PMID:18704167
-
Echavarría-Consuegra, Liliana; Flipse, Jacky; Fernández, Geysson Javier; Kluiver, Joost; van den Berg, Anke; Urcuqui-Inchima, Silvio; Smit, Jolanda M.
2017-01-01
Background Due to the high burden of dengue disease worldwide, a better understanding of the interactions between dengue virus (DENV) and its human host cells is of the utmost importance. Although microRNAs modulate the outcome of several viral infections, their contribution to DENV replication is poorly understood. Methods and principal findings We investigated the microRNA expression profile of primary human macrophages challenged with DENV and deciphered the contribution of microRNAs to infection. To this end, human primary macrophages were challenged with GFP-expressing DENV and sorted to differentiate between truly infected cells (DENV-positive) and DENV-exposed but non-infected cells (DENV-negative cells). The miRNAome was determined by small RNA-Seq analysis and the effect of differentially expressed microRNAs on DENV yield was examined. Five microRNAs were differentially expressed in human macrophages challenged with DENV. Of these, miR-3614-5p was found upregulated in DENV-negative cells and its overexpression reduced DENV infectivity. The cellular targets of miR-3614-5p were identified by liquid chromatography/mass spectrometry and western blot. Adenosine deaminase acting on RNA 1 (ADAR1) was identified as one of the targets of miR-3614-5p and was shown to promote DENV infectivity at early time points post-infection. Conclusion/Significance Overall, miRNAs appear to play a limited role in DENV replication in primary human macrophages. The miRNAs that were found upregulated in DENV-infected cells did not control the production of infectious virus particles. On the other hand, miR-3614-5p, which was upregulated in DENV-negative macrophages, reduced DENV infectivity and regulated ADAR1 expression, a protein that facilitates viral replication. PMID:29045406
-
Immunogenicity and efficacy of a chimpanzee adenovirus-vectored Rift Valley fever vaccine in mice.
Warimwe, George M; Lorenzo, Gema; Lopez-Gil, Elena; Reyes-Sandoval, Arturo; Cottingham, Matthew G; Spencer, Alexandra J; Collins, Katharine A; Dicks, Matthew D J; Milicic, Anita; Lall, Amar; Furze, Julie; Turner, Alison V; Hill, Adrian V S; Brun, Alejandro; Gilbert, Sarah C
2013-12-05
Rift Valley Fever (RVF) is a viral zoonosis that historically affects livestock production and human health in sub-Saharan Africa, though epizootics have also occurred in the Arabian Peninsula. Whilst an effective live-attenuated vaccine is available for livestock, there is currently no licensed human RVF vaccine. Replication-deficient chimpanzee adenovirus (ChAd) vectors are an ideal platform for development of a human RVF vaccine, given the low prevalence of neutralizing antibodies against them in the human population, and their excellent safety and immunogenicity profile in human clinical trials of vaccines against a wide range of pathogens. Here, in BALB/c mice, we evaluated the immunogenicity and efficacy of a replication-deficient chimpanzee adenovirus vector, ChAdOx1, encoding the RVF virus envelope glycoproteins, Gn and Gc, which are targets of virus neutralizing antibodies. The ChAdOx1-GnGc vaccine was assessed in comparison to a replication-deficient human adenovirus type 5 vector encoding Gn and Gc (HAdV5-GnGc), a strategy previously shown to confer protective immunity against RVF in mice. A single immunization with either of the vaccines conferred protection against RVF virus challenge eight weeks post-immunization. Both vaccines elicited RVF virus neutralizing antibody and a robust CD8+ T cell response. Together the results support further development of RVF vaccines based on replication-deficient adenovirus vectors, with ChAdOx1-GnGc being a potential candidate for use in future human clinical trials.
-
Lopker, Michael J.; Del Prete, Gregory Q.; Estes, Jacob D.; Li, Hui; Reid, Carolyn; Newman, Laura; Lipkey, Leslie; Camus, Celine; Easlick, Juliet L.; Wang, Shuyi; Decker, Julie M.; Bar, Katharine J.; Learn, Gerald; Pal, Ranajit; Weiss, Deborah E.; Hahn, Beatrice H.; Lifson, Jeffrey D.; Shaw, George M.
2016-01-01
ABSTRACT Currently available simian immunodeficiency virus (SIV) infectious molecular clones (IMCs) and isolates used in nonhuman primate (NHP) models of AIDS were originally derived from infected macaques during chronic infection or end stage disease and may not authentically recapitulate features of transmitted/founder (T/F) genomes that are of particular interest in transmission, pathogenesis, prevention, and treatment studies. We therefore generated and characterized T/F IMCs from genetically and biologically heterogeneous challenge stocks of SIVmac251 and SIVsmE660. Single-genome amplification (SGA) was used to identify full-length T/F genomes present in plasma during acute infection resulting from atraumatic rectal inoculation of Indian rhesus macaques with low doses of SIVmac251 or SIVsmE660. All 8 T/F clones yielded viruses that were infectious and replication competent in vitro, with replication kinetics similar to those of the widely used chronic-infection-derived IMCs SIVmac239 and SIVsmE543. Phenotypically, the new T/F virus strains exhibited a range of neutralization sensitivity profiles. Four T/F virus strains were inoculated into rhesus macaques, and each exhibited typical SIV replication kinetics. The SIVsm T/F viruses were sensitive to TRIM5α restriction. All T/F viruses were pathogenic in rhesus macaques, resulting in progressive CD4+ T cell loss in gastrointestinal tissues, peripheral blood, and lymphatic tissues. The animals developed pathological immune activation; lymphoid tissue damage, including fibrosis; and clinically significant immunodeficiency leading to AIDS-defining clinical endpoints. These T/F clones represent a new molecular platform for the analysis of virus transmission and immunopathogenesis and for the generation of novel “bar-coded” challenge viruses and next-generation simian-human immunodeficiency viruses that may advance the HIV/AIDS vaccine agenda. IMPORTANCE Nonhuman primate research has relied on only a few infectious molecular clones for a myriad of diverse research projects, including pathogenesis, preclinical vaccine evaluations, transmission, and host-versus-pathogen interactions. With new data suggesting a selected phenotype of the virus that causes infection (i.e., the transmitted/founder virus), we sought to generate and characterize infectious molecular clones from two widely used simian immunodeficiency virus lineages (SIVmac251 and SIVsmE660). Although the exact requirements necessary to be a T/F virus are not yet fully understood, we generated cloned viruses with all the necessary characteristic of a successful T/F virus. The cloned viruses revealed typical acute and set point viral-load dynamics with pathological immune activation, lymphoid tissue damage progressing to significant immunodeficiency, and AIDS-defining clinical endpoints in some animals. These T/F clones represent a new molecular platform for studies requiring authentic T/F viruses. PMID:27412591
-
Laurie, Karen L; Horman, William; Carolan, Louise A; Chan, Kok Fei; Layton, Daniel; Bean, Andrew; Vijaykrishna, Dhanasekaran; Reading, Patrick C; McCaw, James M; Barr, Ian G
2018-01-30
Two influenza B virus lineages, B/Victoria and B/Yamagata, cocirculate in the human population. While the lineages are serologically distinct, cross-reactive responses to both lineages have been detected. Viral interference describes the situation whereby infection with one virus limits infection and replication of a second virus. We investigated the potential for viral interference between the influenza B virus lineages. Ferrets were infected and then challenged 3, 10, or 28 days later with pairs of influenza B/Victoria and B/Yamagata viruses. Viral interference occurred at challenge intervals of 3 and 10 days and occasionally at 28 days. At the longer interval, shedding of challenge virus was reduced, and this correlated with cross-reactive interferon γ responses from lymph nodes from virus-infected animals. Viruses from both lineages could prevent or significantly limit subsequent infection with a virus from the other lineage. Coinfections were rare, indicating the potential for reassortment between lineages is limited. These data suggest that innate and cross-reactive immunity mediate viral interference and that this may contribute to the dominance of a specific influenza B virus lineage in any given influenza season. Furthermore, infection with one influenza B virus lineage may be beneficial in protecting against subsequent infection with either influenza B virus lineage. © The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.
-
Kolliopoulou, Anna; Taning, Clauvis N. T.; Smagghe, Guy; Swevers, Luc
2017-01-01
RNAi is applied as a new and safe method for pest control in agriculture but efficiency and specificity of delivery of dsRNA trigger remains a critical issue. Various agents have been proposed to augment dsRNA delivery, such as engineered micro-organisms and synthetic nanoparticles, but the use of viruses has received relatively little attention. Here we present a critical view of the potential of the use of recombinant viruses for efficient and specific delivery of dsRNA. First of all, it requires the availability of plasmid-based reverse genetics systems for virus production, of which an overview is presented. For RNA viruses, their application seems to be straightforward since dsRNA is produced as an intermediate molecule during viral replication, but DNA viruses also have potential through the production of RNA hairpins after transcription. However, application of recombinant virus for dsRNA delivery may not be straightforward in many cases, since viruses can encode RNAi suppressors, and virus-induced silencing effects can be determined by the properties of the encoded RNAi suppressor. An alternative is virus-like particles that retain the efficiency and specificity determinants of natural virions but have encapsidated non-replicating RNA. Finally, the use of viruses raises important safety issues which need to be addressed before application can proceed. PMID:28659820
-
RNA interference inhibits yellow fever virus replication in vitro and in vivo.
Pacca, Carolina C; Severino, Adriana A; Mondini, Adriano; Rahal, Paula; D'avila, Solange G P; Cordeiro, José Antonio; Nogueira, Mara Correa Lelles; Bronzoni, Roberta V M; Nogueira, Maurício L
2009-04-01
RNA interference (RNAi) is a process that is induced by double stranded RNA and involves the degradation of specific sequences of mRNA in the cytoplasm of the eukaryotic cells. It has been used as an antiviral tool against many viruses, including flaviviruses. The genus Flavivirus contains the most important arboviruses in the world, i.e., dengue (DENV) and yellow fever (YFV). In our study, we investigated the in vitro and in vivo effect of RNAi against YFV. Using stable cell lines that expressed RNAi against YFV, the cell lines were able to inhibit as much as 97% of the viral replication. Two constructions (one against NS1 and the other against E region of YFV genome) were able to protect the adult Balb/c mice against YFV challenge. The histopathologic analysis demonstrated an important protection of the central nervous system by RNAi after 10 days of viral challenge. Our data suggests that RNAi is a potential viable therapeutic weapon against yellow fever.
-
Spackman, Erica; Pantin-Jackwood, Mary; Swayne, David E; Suarez, David L; Kapczynski, Darrell R
2015-03-01
H7N9 influenza A first caused human infections in early 2013 in China. Virus genetics, histories of patient exposures to poultry, and previous experimental studies suggest the source of the virus is a domestic avian species, such as chickens. In order to better understand the ecology of this H7N9 in chickens, we evaluated the infectious dose and pathogenesis of A/Anhui/1/2013 H7N9 in two common breeds of chickens, White Leghorns (table-egg layers) and White Plymouth Rocks (meat chickens). No morbidity or mortality were observed with doses of 10(6) or 10(8)EID50/bird when administered by the upper-respiratory route, and the mean infectious dose (10(6) EID50) was higher than expected, suggesting that the virus is poorly adapted to chickens. Virus was shed at higher titers and spread to the kidneys in chickens inoculated by the intravenous route. Challenge experiments with three other human-origin H7N9 viruses showed a similar pattern of virus replication. Published by Elsevier Inc.
-
Mutation of E1 glycoprotein of classical swine fever virus affects viral virulence in swine.
Risatti, G R; Holinka, L G; Lu, Z; Kutish, G F; Tulman, E R; French, R A; Sur, J H; Rock, D L; Borca, M V
2005-12-05
Transposon linker insertion mutagenesis of a full-length infectious clone (IC) (pBIC) of the pathogenic classical swine fever virus (CSFV) strain Brescia was used to identify genetic determinants of CSFV virulence and host range. Here, we characterize a virus mutant, RB-C22v, possessing a 19-residue insertion at the carboxyl terminus of E1 glycoprotein. Although RB-C22v exhibited normal growth characteristics in primary porcine macrophage cell cultures, the major target cell of CSFV in vivo, it was markedly attenuated in swine. All RB-C22v-infected pigs survived infection remaining clinically normal in contrast to the 100% mortality observed for BICv-infected animals. Comparative pathogenesis studies demonstrated a delay in RB-C22v spread to, and decreased replication in the tonsils, a 10(2) to 10(7) log10 reduction in virus titers in lymphoid tissues and blood, and an overall delay in generalization of infection relative to BICv. Notably, RB-C22v-infected animals were protected from clinical disease when challenged with pathogenic BICv at 3, 5, 7, and 21 days post-RB-C22v inoculation. Viremia, viral replication in tissues, and oronasal shedding were reduced in animals challenged at 7 and 21 DPI. Notably BICv-specific RNA was not detected in tonsils of challenged animals. These results indicate that a carboxyl-terminal domain of E1 glycoprotein affects virulence of CSFV in swine, and they demonstrate that mutation of this domain provides the basis for a rationally designed and efficacious live-attenuated CSF vaccine.
-
Architecture and biogenesis of plus-strand RNA virus replication factories
Paul, David; Bartenschlager, Ralf
2013-01-01
Plus-strand RNA virus replication occurs in tight association with cytoplasmic host cell membranes. Both, viral and cellular factors cooperatively generate distinct organelle-like structures, designated viral replication factories. This compartmentalization allows coordination of the different steps of the viral replication cycle, highly efficient genome replication and protection of the viral RNA from cellular defense mechanisms. Electron tomography studies conducted during the last couple of years revealed the three dimensional structure of numerous plus-strand RNA virus replication compartments and highlight morphological analogies between different virus families. Based on the morphology of virus-induced membrane rearrangements, we propose two separate subclasses: the invaginated vesicle/spherule type and the double membrane vesicle type. This review discusses common themes and distinct differences in the architecture of plus-strand RNA virus-induced membrane alterations and summarizes recent progress that has been made in understanding the complex interplay between viral and co-opted cellular factors in biogenesis and maintenance of plus-strand RNA virus replication factories. PMID:24175228
-
Vaccination of chickens decreased Newcastle disease virus contamination in eggs.
Sá E Silva, Mariana; Susta, Leonardo; Moresco, Kira; Swayne, David E
2016-01-01
Newcastle disease is an important health issue of poultry causing major economic losses and inhibits trade worldwide. Vaccination is used as a control measure, but it is unknown whether vaccination will prevent virus contamination of eggs. In this study, hens were sham-vaccinated or received one or two doses of inactivated LaSota vaccine, followed three weeks later by virulent Newcastle disease virus (NDV) challenge. Eggs were collected daily and shell, albumen and yolk were subjected to virus isolation, as were oral and cloacal swabs at 2 and 4 days post-challenge (dpc). A second experiment evaluated the distribution of the virus in the reproductive tract of non-vaccinates. All vaccinated chickens survived challenge, and the levels of virus shed from cloacal swabs were decreased significantly when compared to shams. In non-vaccinated hens, virus was detected in the ovary and all segments of the oviduct. Yolk, albumen and eggshell surface from eggs laid at day 4 and 5 post-infection by sham-vaccinated hens were positive for NDV, but eggs from LaSota vaccinated hens lacked virus in internal egg components (i.e. yolk and albumen) and had reduction in the number of positive eggshell surfaces. These results indicate virulent NDV can replicate in the reproductive tract of hens and contaminate internal components of eggs and eggshell surface, but vaccination was able to prevent internal egg contamination, reducing eggshell surface contamination, and reducing shedding from digestive and respiratory tracts in virulent NDV challenged hens.
-
Role of MAPK/MNK1 signaling in virus replication.
Kumar, Ram; Khandelwal, Nitin; Thachamvally, Riyesh; Tripathi, Bhupendra Nath; Barua, Sanjay; Kashyap, Sudhir Kumar; Maherchandani, Sunil; Kumar, Naveen
2018-06-01
Viruses are obligate intracellular parasites; they heavily depend on the host cell machinery to effectively replicate and produce new progeny virus particles. Following viral infection, diverse cell signaling pathways are initiated by the cells, with the major goal of establishing an antiviral state. However, viruses have been shown to exploit cellular signaling pathways for their own effective replication. Genome-wide siRNA screens have also identified numerous host factors that either support (proviral) or inhibit (antiviral) virus replication. Some of the host factors might be dispensable for the host but may be critical for virus replication; therefore such cellular factors may serve as targets for development of antiviral therapeutics. Mitogen activated protein kinase (MAPK) is a major cell signaling pathway that is known to be activated by diverse group of viruses. MAPK interacting kinase 1 (MNK1) has been shown to regulate both cap-dependent and internal ribosomal entry sites (IRES)-mediated mRNA translation. In this review we have discuss the role of MAPK in virus replication, particularly the role of MNK1 in replication and translation of viral genome. Copyright © 2018 Elsevier B.V. All rights reserved.
-
Mok, Hoyin; Cheng, Xing; Xu, Qi; Zengel, James R; Parhy, Bandita; Zhao, Jackie; Wang, C. Kathy; Jin, Hong
2012-01-01
Live attenuated recombinant measles vaccine virus (MV) Edmonston-Zagreb (EZ) strain was evaluated as a viral vector to express the ectodomains of fusion protein of respiratory syncytial virus (RSV F) or glycoprotein 350 of Epstein-Barr virus (EBV gp350) as candidate vaccines for prophylaxis of RSV and EBV. The glycoprotein gene was inserted at the 1st or the 3rd position of the measles virus genome and the recombinant viruses were generated. Insertion of the foreign gene at the 3rd position had a minimal impact on viral replication in vitro. RSV F or EBV gp350 protein was secreted from infected cells. In cotton rats, EZ-RSV F and EZ-EBV gp350 induced MV- and insert-specific antibody responses. In addition, both vaccines also induced insert specific interferon gamma (IFN-γ) secreting T cell response. EZ-RSV F protected cotton rats from pulmonary replication of RSV A2 challenge infection. In rhesus macaques, although both EZ-RSV F and EZ-EBV gp350 induced MV specific neutralizing antibody responses, only RSV F specific antibody response was detected. Thus, the immunogenicity of the foreign antigens delivered by measles vaccine virus is dependent on the nature of the insert and the animal models used for vaccine evaluation. PMID:22383906
-
Duhan, Vikas; Khairnar, Vishal; Friedrich, Sarah-Kim; Zhou, Fan; Gassa, Asmae; Honke, Nadine; Shaabani, Namir; Gailus, Nicole; Botezatu, Lacramioara; Khandanpour, Cyrus; Dittmer, Ulf; Häussinger, Dieter; Recher, Mike; Hardt, Cornelia; Lang, Philipp A.; Lang, Karl S.
2016-01-01
Clinically used human vaccination aims to induce specific antibodies that can guarantee long-term protection against a pathogen. The reasons that other immune components often fail to induce protective immunity are still debated. Recently we found that enforced viral replication in secondary lymphoid organs is essential for immune activation. In this study we used the lymphocytic choriomeningitis virus (LCMV) to determine whether enforced virus replication occurs in the presence of virus-specific antibodies or virus-specific CD8+ T cells. We found that after systemic recall infection with LCMV-WE the presence of virus-specific antibodies allowed intracellular replication of virus in the marginal zone of spleen. In contrast, specific antibodies limited viral replication in liver, lung, and kidney. Upon recall infection with the persistent virus strain LCMV-Docile, viral replication in spleen was essential for the priming of CD8+ T cells and for viral control. In contrast to specific antibodies, memory CD8+ T cells inhibited viral replication in marginal zone but failed to protect mice from persistent viral infection. We conclude that virus-specific antibodies limit viral infection in peripheral organs but still allow replication of LCMV in the marginal zone, a mechanism that allows immune boosting during recall infection and thereby guarantees control of persistent virus. PMID:26805453
-
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. Finally, this report describes histological examination of mouse lungs after vaccination and challenge. Vaccinated mice that were subsequently challenged had significantly greater lung lesion scores than unvaccinated challenged mice. The lesions were primarily peribronchiolar and perivascular infiltrations of polymorphonuclear cells and lymphocytes. Further work will establish whether these pulmonary changes are a desirable immune response to virus invasion or a potential immunopathogenic hazard. The results have important implications for planning a strategy of vaccination against RS virus and emphasize potential dangers that may attend the use of recombinant VV as vaccines.
-
Mühlberger, Elke; Weik, Michael; Volchkov, Viktor E.; Klenk, Hans-Dieter; Becker, Stephan
1999-01-01
The members of the family Filoviridae, Marburg virus (MBGV) and Ebola virus (EBOV), are very similar in terms of morphology, genome organization, and protein composition. To compare the replication and transcription strategies of both viruses, an artificial replication system based on the vaccinia virus T7 expression system was established for EBOV. Specific transcription and replication of an artificial monocistronic minireplicon was demonstrated by reporter gene expression and detection of the transcribed and replicated RNA species. As it was shown previously for MBGV, three of the four EBOV nucleocapsid proteins, NP, VP35, and L, were essential and sufficient for replication. In contrast to MBGV, EBOV-specific transcription was dependent on the presence of the fourth nucleocapsid protein, VP30. When EBOV VP30 was replaced by MBGV VP30, EBOV-specific transcription was observed but with lower efficiency. Exchange of NP, VP35, and L between the two replication systems did not lead to detectable reporter gene expression. It was further observed that neither MBGV nor EBOV were able to replicate the heterologous minigenomes. A chimeric minigenome, however, containing the EBOV leader and the MBGV trailer was encapsidated, replicated, transcribed, and packaged by both viruses. PMID:9971816
-
Lamontagne, Jason; Steel, Laura F; Bouchard, Michael J
2015-01-01
Chronic infection with the hepatitis B virus (HBV) is the leading risk factor for the development of hepatocellular carcinoma (HCC). With nearly 750000 deaths yearly, hepatocellular carcinoma is the second highest cause of cancer-related death in the world. Unfortunately, the molecular mechanisms that contribute to the development of HBV-associated HCC remain incompletely understood. Recently, microRNAs (miRNAs), a family of small non-coding RNAs that play a role primarily in post-transcriptional gene regulation, have been recognized as important regulators of cellular homeostasis, and altered regulation of miRNA expression has been suggested to play a significant role in virus-associated diseases and the development of many cancers. With this in mind, many groups have begun to investigate the relationship between miRNAs and HBV replication and HBV-associated disease. Multiple findings suggest that some miRNAs, such as miR-122, and miR-125 and miR-199 family members, are playing a role in HBV replication and HBV-associated disease, including the development of HBV-associated HCC. In this review, we discuss the current state of our understanding of the relationship between HBV and miRNAs, including how HBV affects cellular miRNAs, how these miRNAs impact HBV replication, and the relationship between HBV-mediated miRNA regulation and HCC development. We also address the impact of challenges in studying HBV, such as the lack of an effective model system for infectivity and a reliance on transformed cell lines, on our understanding of the relationship between HBV and miRNAs, and propose potential applications of miRNA-related techniques that could enhance our understanding of the role miRNAs play in HBV replication and HBV-associated disease, ultimately leading to new therapeutic options and improved patient outcomes. PMID:26139985
-
Lamontagne, Jason; Steel, Laura F; Bouchard, Michael J
2015-06-28
Chronic infection with the hepatitis B virus (HBV) is the leading risk factor for the development of hepatocellular carcinoma (HCC). With nearly 750000 deaths yearly, hepatocellular carcinoma is the second highest cause of cancer-related death in the world. Unfortunately, the molecular mechanisms that contribute to the development of HBV-associated HCC remain incompletely understood. Recently, microRNAs (miRNAs), a family of small non-coding RNAs that play a role primarily in post-transcriptional gene regulation, have been recognized as important regulators of cellular homeostasis, and altered regulation of miRNA expression has been suggested to play a significant role in virus-associated diseases and the development of many cancers. With this in mind, many groups have begun to investigate the relationship between miRNAs and HBV replication and HBV-associated disease. Multiple findings suggest that some miRNAs, such as miR-122, and miR-125 and miR-199 family members, are playing a role in HBV replication and HBV-associated disease, including the development of HBV-associated HCC. In this review, we discuss the current state of our understanding of the relationship between HBV and miRNAs, including how HBV affects cellular miRNAs, how these miRNAs impact HBV replication, and the relationship between HBV-mediated miRNA regulation and HCC development. We also address the impact of challenges in studying HBV, such as the lack of an effective model system for infectivity and a reliance on transformed cell lines, on our understanding of the relationship between HBV and miRNAs, and propose potential applications of miRNA-related techniques that could enhance our understanding of the role miRNAs play in HBV replication and HBV-associated disease, ultimately leading to new therapeutic options and improved patient outcomes.
-
Hosoya, Noriaki; Su, Zhaohui; Wilkin, Timothy; Gulick, Roy M.; Flexner, Charles; Hughes, Michael D.; Skolnik, Paul R.; Giguel, Françoise; Greaves, Wayne L.; Coakley, Eoin; Kuritzkes, Daniel R.
2009-01-01
Detection of CXCR4-using human immunodeficiency virus by the Trofile assay was compared to that by assays using virus isolates or replication-competent recombinants. Concordance with the Trofile assay was good, but assays using replicating viruses did not increase substantially the ability to detect the presence of CXCR4-using virus. PMID:19494074
-
Ferrier-Rembert, Audrey; Drillien, Robert; Tournier, Jean-Nicolas; Garin, Daniel; Crance, Jean-Marc
2008-03-25
This study assessed three non-replicating smallpox vaccine candidates (modified vaccinia Ankara (MVA), NYVAC and HR) for their immunogenicity and ability to protect mice against an intranasal cowpox virus challenge and compared them with the traditional replicating vaccine. A single immunisation with the non-replicating vaccines induced a complete protection from death at short-term, but was not fully protective when mice were challenged 150 days post-vaccination with protection correlated with the specific neutralizing antibodies and CD4(+) T-cells responses. Prime-boost vaccination enabled effective long-term protection from death for mice vaccinated with MVA, but protection from disease and CD4(+) T-cell level were lower than the ones induced by the traditional vaccine over the long-term period. Further investigations are necessary with MVA to determine the optimal conditions of immunisation to induce at long-term immunogenicity and protection observed with the 1st generation smallpox vaccine.
-
Ma, Dzwokai; George, Cyril X; Nomburg, Jason; Pfaller, Christian K; Cattaneo, Roberto; Samuel, Charles E
2017-12-13
Replication of negative-strand RNA viruses occurs in association with discrete cytoplasmic foci called inclusion bodies. Whereas inclusion bodies represent a prominent subcellular structure induced by viral infection, our knowledge of the cellular protein components involved in inclusion body formation and function is limited. Using measles virus-infected HeLa cells, we found that the WD repeat-containing protein 5 (WDR5), a subunit of histone H3 lysine 4 methyltransferases, was selectively recruited to virus-induced inclusion bodies. Furthermore, WDR5 was found in complexes containing viral proteins associated with RNA replication. WDR5 was not detected with mitochondria, stress granules, or other known secretory or endocytic compartments of infected cells. WDR5 deficiency decreased both viral protein production and infectious virus yields. Interferon production was modestly increased in WDR5 deficient cells. Thus, our study identifies WDR5 as a novel viral inclusion body-associated cellular protein and suggests a role for WDR5 in promoting viral replication. IMPORTANCE Measles virus is a human pathogen that remains a global concern with more than 100,000 measles-related deaths annually despite the availability of an effective vaccine. As measles continues to cause significant morbidity and mortality, understanding the virus-host interactions at the molecular level that affect virus replication efficiency is important for development and optimization of treatment procedures. Measles virus is an RNA virus that encodes six genes and replicates in the cytoplasm of infected cells in discrete cytoplasmic replication bodies, though little is known of the biochemical nature of these structures. Here we show that the cellular protein WDR5 is enriched in the cytoplasmic viral replication factories and enhances virus growth. WDR5-containing protein complex includes viral proteins responsible for viral RNA replication. Thus, we have identified WDR5 as a host factor that enhances the replication of measles virus. Copyright © 2017 American Society for Microbiology.
-
Mikalsen, Aase B; Haugland, Oyvind; Rode, Marit; Solbakk, Inge Tom; Evensen, Oystein
2012-01-01
Heart and skeletal inflammation (HSMI) of farmed Atlantic salmon (Salmo salar L.) is a disease characterized by a chronic myocarditis involving the epicardium and the compact and spongious part of the heart ventricle. Chronic myositis of the red skeletal muscle is also a typical finding of HSMI. Piscine reovirus (PRV) has been detected by real-time PCR from farmed and wild salmon with and without typical changes of HSMI and thus the causal relationship between presence of virus and the disease has not been fully determined. In this study we show that the Atlantic salmon reovirus (ASRV), identical to PRV, can be passaged in GF-1 cells and experimental challenge of naïve Atlantic salmon with cell culture passaged reovirus results in cardiac and skeletal muscle pathology typical of HSMI with onset of pathology from 6 weeks, peaking by 9 weeks post challenge. ASRV replicates in heart tissue and the peak level of virus replication coincides with peak of heart lesions. We further demonstrate mRNA transcript assessment and in situ characterization that challenged fish develop a CD8+ T cell myocarditis.
-
Replicating Single-Cycle Adenovirus Vectors Generate Amplified Influenza Vaccine Responses.
Crosby, Catherine M; Matchett, William E; Anguiano-Zarate, Stephanie S; Parks, Christopher A; Weaver, Eric A; Pease, Larry R; Webby, Richard J; Barry, Michael A
2017-01-15
Head-to-head comparisons of conventional influenza vaccines with adenovirus (Ad) gene-based vaccines demonstrated that these viral vectors can mediate more potent protection against influenza virus infection in animal models. In most cases, Ad vaccines are engineered to be replication-defective (RD-Ad) vectors. In contrast, replication-competent Ad (RC-Ad) vaccines are markedly more potent but risk causing adenovirus diseases in vaccine recipients and health care workers. To harness antigen gene replication but avoid production of infectious virions, we developed "single-cycle" adenovirus (SC-Ad) vectors. Previous work demonstrated that SC-Ads amplify transgene expression 100-fold and produce markedly stronger and more persistent immune responses than RD-Ad vectors in Syrian hamsters and rhesus macaques. To test them as potential vaccines, we engineered RD and SC versions of adenovirus serotype 6 (Ad6) to express the hemagglutinin (HA) gene from influenza A/PR/8/34 virus. We show here that it takes approximately 33 times less SC-Ad6 than RD-Ad6 to produce equal amounts of HA antigen in vitro SC-Ad produced markedly higher HA binding and hemagglutination inhibition (HAI) titers than RD-Ad in Syrian hamsters. SC-Ad-vaccinated cotton rats had markedly lower influenza titers than RD-Ad-vaccinated animals after challenge with influenza A/PR/8/34 virus. These data suggest that SC-Ads may be more potent vaccine platforms than conventional RD-Ad vectors and may have utility as "needle-free" mucosal vaccines. Most adenovirus vaccines that are being tested are replication-defective adenoviruses (RD-Ads). This work describes testing newer single-cycle adenovirus (SC-Ad) vectors that replicate transgenes to amplify protein production and immune responses. We show that SC-Ads generate markedly more influenza virus hemagglutinin protein and require substantially less vector to generate the same immune responses as RD-Ad vectors. SC-Ads therefore hold promise to be more potent vectors and vaccines than current RD-Ad vectors. Copyright © 2017 Crosby et al.
-
Genz, Berit; Nolden, Tobias; Negatsch, Alexandra; Teifke, Jens-Peter; Conzelmann, Karl-Klaus; Finke, Stefan
2012-01-01
The glycoprotein G of lyssaviruses is the major determinant of virus pathogenicity and serves as a target for immunological responses to virus infections. However, assessment of the exact contribution of lyssavirus G proteins to observed differences in the pathogenicity of lyssavirus species is challenging, since the direct comparison of natural lyssaviruses does not allow specific ascription to individual virus proteins or domains. Here we describe the generation and characterization of recombinant rabies viruses (RABV) that express chimeric G proteins comprising of a RABV cytoplasma domain fused to transmembrane and ectodomain G sequences of a virulent RABV (challenge virus standard; CVS-11) or two European bat lyssaviruses (EBLV- and EBLV-2). These "envelope-switched" recombinant viruses were recovered from cDNAs. Similar growth kinetics and protein expression in neuroblastoma cell cultures and successful targeting of primary neurons showed that the chimeric G proteins were able to replace the authentic G protein in a RABV based virus vector. Inoculation of six week old CD-1 mice by the intracranial (i. c.) route of infection further demonstrated that all recombinant viruses were able to spread in the brain and to induce disease. The "envelope-switched" RABV therefore represent an important tool to further investigate the influence of lyssavirus ectodomains on virus tropism, and pathogenicity.
-
The Function of Herpes Simplex Virus Genes: A Primer for Genetic Engineering of Novel Vectors
NASA Astrophysics Data System (ADS)
Roizman, Bernard
1996-10-01
Herpes simplex virus vectors are being developed for delivery and expression of human genes to the central nervous system, selective destruction of cancer cells, and as carriers for genes encoding antigens that induce protective immunity against infectious agents. Vectors constructed to meet these objectives must differ from wild-type virus with respect to host range, reactivation from latency, and expression of viral genes. The vectors currently being developed are (i) helper free amplicons, (ii) replication defective viruses, and (iii) genetically engineered replication competent viruses with restricted host range. Whereas the former two types of vectors require stable, continuous cell lines expressing viral genes for their replication, the replication competent viruses will replicate on approved primary human cell strains.
-
A universal mammalian vaccine cell line substrate.
Murray, Jackelyn; Todd, Kyle V; Bakre, Abhijeet; Orr-Burks, Nichole; Jones, Les; Wu, Weilin; Tripp, Ralph A
2017-01-01
Using genome-wide small interfering RNA (siRNA) screens for poliovirus, influenza A virus and rotavirus, we validated the top 6 gene hits PV, RV or IAV to search for host genes that when knocked-down (KD) enhanced virus permissiveness and replication over wild type Vero cells or HEp-2 cells. The enhanced virus replication was tested for 12 viruses and ranged from 2-fold to >1000-fold. There were variations in virus-specific replication (strain differences) across the cell lines examined. Some host genes (CNTD2, COQ9, GCGR, NDUFA9, NEU2, PYCR1, SEC16G, SVOPL, ZFYVE9, and ZNF205) showed that KD resulted in enhanced virus replication. These findings advance platform-enabling vaccine technology, the creation of diagnostic cells substrates, and are informative about the host mechanisms that affect virus replication in mammalian cells.
-
The pathogenicity of thymidine kinase-deficient mutants of herpes simplex virus in mice.
Field, H. J.; Wildy, P.
1978-01-01
The pathogenicity for mice of two mutants of herpes simplex virus (type 1 and type 2), which fail to induce thymidine kinase, were compared with their respective parent strains. The mutants were much less virulent than the parents following either intracerebral or peripheral inoculation. The replication of the virus at the site of inoculation and its progression into the nervous system were studied. Following a very large inoculum in the ear, the type 1 mutant was found to establish a latent infection in the cervical dorsal root ganglia. Mice inoculated intracerebrally with small doses of the mutant viruses were solidly immune to challenge with lethal doses of the parent strain. PMID:212476
-
The pathogenicity of thymidine kinase-deficient mutants of herpes simplex virus in mice.
Field, H J; Wildy, P
1978-10-01
The pathogenicity for mice of two mutants of herpes simplex virus (type 1 and type 2), which fail to induce thymidine kinase, were compared with their respective parent strains. The mutants were much less virulent than the parents following either intracerebral or peripheral inoculation. The replication of the virus at the site of inoculation and its progression into the nervous system were studied. Following a very large inoculum in the ear, the type 1 mutant was found to establish a latent infection in the cervical dorsal root ganglia. Mice inoculated intracerebrally with small doses of the mutant viruses were solidly immune to challenge with lethal doses of the parent strain.
-
Fooks, A R; Jeevarajah, D; Lee, J; Warnes, A; Niewiesk, S; ter Meulen, V; Stephenson, J R; Clegg, J C
1998-05-01
The genes encoding the measles virus (MV) haemagglutinin (H) and fusion (F) proteins were placed under the control of the human cytomegalovirus immediate early promoter in a replication-deficient adenovirus vector. Immunofluorescence and radioimmune precipitation demonstrated the synthesis of each protein and biological activity was confirmed by the detection of haemadsorption and fusion activities in infected cells. Oral as well as parenteral administration of the H-expressing recombinant adenovirus elicited a significant protective response in mice challenged with MV. While the F-expressing adenovirus failed to protect mice, cotton rats immunized with either the H- or F-expressing recombinant showed reduced MV replication in the lungs. Antibodies elicited in mice following immunization with either recombinant had no in vitro neutralizing activity, suggesting a protective mechanism involving a cell-mediated immune response. This study demonstrates the feasibility of using oral administration of adenovirus recombinants to induce protective responses to heterologous proteins.
-
Microscopic Observation of Self-Propagation of Calcifying Nanoparticles (Nanobacteria)
NASA Technical Reports Server (NTRS)
Mathew, Grace; McKay, David S.; Ciftcioglu, Neva
2007-01-01
Biologists typically define living organisms as carbon and water-based cellular forms with :self-replication" as the fundamental trait of the life process. However, this standard dictionary definition of life does not help scientists to categorize self-replicators like viruses, prions, proteons and artificial life. CNP also named nanobacteria were discovered in early 1990s as about 100 nanometer-sized bacteria-like particles with unique apatite mineral-shells around them, and found to be associated with pathological-calcification related diseases. Although CNP have been isolated and cultured from mammalian blood and diseased calcified tissues, and their biomineralizing properties well established, their biological nature and self-replicating capability have always been severely challenged. The terms "self-replication", "self-assembly" or "self-propagation" have been widely used for all systems including nanomachines, crystals, computer viruses and memes. In a simple taxonomy, all biological and non-biological "self replicators", have been classified into "living" or "nonliving" based on the properties of the systems and the amount of support they require to self-replicate. To enhance our understanding about self-replicating nature of CNP, we have investigated their growth in specific culture conditions using conventional inverted light microscope and BioStation IM, Nikon s latest time-lapse imaging system. Their morphological structure was examined using scanning (SEM) and transmission (TEM) electron microscopy. This present study, in conjunction with previous findings of metabolic activity, antibiotic sensitivity, antibody specificity, morphological aspects and infectivity, all concomitantly validate CNP as living self-replicators.
-
El-Shesheny, Rabeh; Feeroz, Mohammed M; Krauss, Scott; Vogel, Peter; McKenzie, Pamela; Webby, Richard J; Webster, Robert G
2018-04-25
Surveillance of wild aquatic birds and free-range domestic ducks in the Tanguar Haor wetlands in Bangladesh has identified influenza virus subtypes H3N6, H7N1, H7N5, H7N9, and H15N9. Molecular characterization of these viruses indicates their contribution to the genesis of new genotypes of H5N1 influenza viruses from clade 2.3.2.1a that are dominant in poultry markets in Bangladesh as well as to the genesis of the highly pathogenic H5N8 virus currently causing disease outbreaks in domestic poultry in Europe and the Middle East. Therefore, we studied the antigenicity, replication, and pathogenicity of influenza viruses isolated from Tanguar Haor in the DBA/2J mouse model. All viruses replicated in the lung without prior mammalian adaptation, and H7N1 and H7N9 viruses caused 100% and 60% mortality, respectively. H7N5 viruses replicated only in the lungs, whereas H7N1 and H7N9 viruses also replicated in the heart, liver, and brain. Replication and transmission studies in mallard ducks showed that H7N1 and H7N9 viruses replicated in ducks without clinical signs of disease and shed at high titers from the cloaca of infected and contact ducks, which could facilitate virus transmission and spread. Our results indicate that H7 avian influenza viruses from free-range ducks can replicate in mammals, cause severe disease, and be efficiently transmitted to contact ducks. Our study highlights the role of free-range ducks in the spread of influenza viruses to other species in live poultry markets and the potential for these viruses to infect and cause disease in mammals.
-
Hoenen, Thomas; Groseth, Allison; de Kok-Mercado, Fabian; Kuhn, Jens H.; Wahl-Jensen, Victoria
2012-01-01
Reverse-genetics systems are powerful tools enabling researchers to study the replication cycle of RNA viruses, including filoviruses and other hemorrhagic fever viruses, as well as to discover new antivirals. They include full-length clone systems as well as a number of life cycle modeling systems. Full-length clone systems allow for the generation of infectious, recombinant viruses, and thus are an important tool for studying the virus replication cycle in its entirety. In contrast, life cycle modeling systems such as minigenome and transcription and replication competent virus-like particle systems can be used to simulate and dissect parts of the virus life cycle outside of containment facilities. Minigenome systems are used to model viral genome replication and transcription, whereas transcription and replication competent virus-like particle systems also model morphogenesis and budding as well as infection of target cells. As such, these modeling systems have tremendous potential to further the discovery and screening of new antivirals targeting hemorrhagic fever viruses. This review provides an overview of currently established reverse genetics systems for hemorrhagic fever-causing negative-sense RNA viruses, with a particular emphasis on filoviruses, and the potential application of these systems for antiviral research. PMID:21699921
-
Fuentes, Sandra; Arenas, Diego; Moore, Martin M; Golding, Hana; Khurana, Surender
2017-01-23
Respiratory Syncytial virus (RSV) is one of the leading causes of pneumonia among infants with no human vaccine or efficient curative treatments. Efforts are underway to develop new RSV vaccines and therapeutics. There is a dire need for animal models for preclinical evaluation and selection of products against RSV. Herein, we developed a whole body bioluminescence imaging to follow replication of RSV A2 virus strain expressing firefly luciferase (RSVA2-line19-FFL) in live BALB/c mice that can be used as an extremely sensitive readout for studying effects of antiviral and vaccines in living mice. Strong bioluminescence signal was detected in the nasal cavity and in the lungs following intranasal infection of mice with RSVA2-line19-FFL. The kinetics of viral replication in lungs quantified by daily live imaging strongly correlated with viral titers measured by ex-vivo plaque assay and by assessing viral RNA by qRT-PCR. Vaccination of mice with a pre-fusion F protein elicited high neutralizing antibody titers conferring strong protective immunity against virus replication in the nasal cavity and lungs. In contrast, post-challenge treatment of mice with the monoclonal antibody Palivizumab two days after infection reduced viral replication in the nasal cavity at day 4, but only modestly reduced virus loads in the lungs by day 5. In contrast to RSV bioluminescence, plaque assay did not detect viral titers in lungs on day 5 in Palivizumab-treated animals. This difference between viral loads measured by the two assays was found to be due to coating of virions with the Palivizumab that blocked infection of target cells in vitro and shows importance of live imaging in evaluation of RSV therapeutics. This recombinant RSV based live imaging animal model is convenient and valuable tool that can be used to study host dissemination of RSV and evaluation of antiviral compounds and vaccines against RSV. Published by Elsevier Ltd.
-
Development of replication-competent viral vectors for HIV vaccine delivery
Parks, Christopher L.; Picker, Louis J.; King, C. Richter
2014-01-01
Purpose of review Briefly describe some of the replication-competent (RC) vectors being investigated for development of candidate HIV vaccines focusing primarily on technologies that have advanced to testing in macaques or have entered clinical trials. Recent findings RC viral vectors have advanced to the stage were decisions can be made regarding future development of HIV vaccines. The viruses being used as RC vector platforms vary considerably, and their unique attributes make it possible to test multiple vaccine design concepts and also mimic various aspects of an HIV infection. RC viral vectors encoding SIV or HIV proteins can be used to safely immunize macaques, and in some cases, there is evidence of significant vaccine efficacy in challenge protection studies. Several live HIV vaccine vectors are in clinical trials to evaluate immunogenicity, safety, the effect of mucosal delivery, and potential effects of pre-existing immunity. Summary A variety of DNA and RNA viruses are being used to develop RC viral vectors for HIV vaccine delivery. Multiple viral vector platforms have proven to be safe and immunogenic with evidence of efficacy in macaques. Some of the more advanced HIV vaccine prototypes based on vesicular stomatitis virus, vaccinia virus, measles virus, and Sendai virus are in clinical trials. PMID:23925000
-
Lipids and RNA virus replication.
Konan, Kouacou V; Sanchez-Felipe, Lorena
2014-12-01
Most viruses rely heavily on their host machinery to successfully replicate their genome and produce new virus particles. Recently, the interaction of positive-strand RNA viruses with the lipid biosynthetic and transport machinery has been the subject of intense investigation. In this review, we will discuss the contribution of various host lipids and related proteins in RNA virus replication and maturation. Copyright © 2014 Elsevier B.V. All rights reserved.
-
Herfst, Sander; Bestebroer, Theo M.; Vaes, Vincent P.; van der Hoeven, Barbara; Koster, Abraham J.; Kremers, Gert-Jan; Scott, Dana P.; Gultyaev, Alexander P.; Sorell, Erin M.; de Graaf, Miranda; Bárcena, Montserrat; Rimmelzwaan, Guus F.; Fouchier, Ron A.
2015-01-01
Bioluminescent and fluorescent influenza A viruses offer new opportunities to study influenza virus replication, tropism and pathogenesis. To date, several influenza A reporter viruses have been described. These strategies typically focused on a single reporter gene (either bioluminescent or fluorescent) in a single virus backbone. However, whilst bioluminescence is suited to in vivo imaging, fluorescent viruses are more appropriate for microscopy. Therefore, the idea l reporter virus varies depending on the experiment in question, and it is important that any reporter virus strategy can be adapted accordingly. Herein, a strategy was developed to create five different reporter viruses in a single virus backbone. Specifically, enhanced green fluorescent protein (eGFP), far-red fluorescent protein (fRFP), near-infrared fluorescent protein (iRFP), Gaussia luciferase (gLUC) and firefly luciferase (fLUC) were inserted into the PA gene segment of A/PR/8/34 (H1N1). This study provides a comprehensive characterisation of the effects of different reporter genes on influenza virus replication and reporter activity. In vivo reporter gene expression, in lung tissues, was only detected for eGFP, fRFP and gLUC expressing viruses. In vitro, the eGFP-expressing virus displayed the best reporter stability and could be used for correlative light electron microscopy (CLEM). This strategy was then used to create eGFP-expressing viruses consisting entirely of pandemic H1N1, highly pathogenic avian influenza (HPAI) H5N1 and H7N9. The HPAI H5N1 eGFP-expressing virus infected mice and reporter gene expression was detected, in lung tissues, in vivo. Thus, this study provides new tools and insights for the creation of bioluminescent and fluorescent influenza A reporter viruses. PMID:26241861
-
NASA Astrophysics Data System (ADS)
Chonis, Taylor Steven
In the upcoming era of extremely large ground-based astronomical telescopes, the design of wide-field spectroscopic survey instrumentation has become increasingly complex due to the linear growth of instrument pupil size with telescope diameter for a constant spectral resolving power. The upcoming Visible Integral field Replicable Unit Spectrograph (VIRUS), a baseline array of 150 copies of a simple integral field spectrograph that will be fed by 3:36 x 104 optical fibers on the upgraded Hobby-Eberly Telescope (HET) at McDonald Observatory, represents one of the first uses of large-scale replication to break the relationship between instrument pupil size and telescope diameter. By dividing the telescope's field of view between a large number of smaller and more manageable instruments, the total information grasp of a traditional monolithic survey spectrograph can be achieved at a fraction of the cost and engineering complexity. To highlight the power of this method, VIRUS will execute the HET Dark Energy Experiment (HETDEX) and survey & 420 degrees2 of sky to an emission line flux limit of ˜ 10-17 erg s-1 cm -2 to detect ˜ 106 Lyman-alpha emitting galaxies (LAEs) as probes of large-scale structure at redshifts of 1:9 < z < 3:5. HETDEX will precisely measure the evolution of dark energy at that epoch, and will simultaneously amass an LAE sample that will be unprecedented for extragalactic astrophysics at the redshifts of interest. Large-scale replication has clear advantages to increasing the total information grasp of a spectrograph, but there are also challenges. In this dissertation, two of these challenges with respect to VIRUS are detailed. First, the VIRUS cryogenic system is discussed, specifically the design and tests of a novel thermal connector and internal camera croygenic components that link the 150 charge-coupled device detectors to the instrument's liquid nitrogen distribution system. Second, the design, testing, and mass production of the suite of volume phase holographic (VPH) diffraction gratings for VIRUS is presented, which highlights the challenge and success associated with producing of a very large number of highly customized optical elements whose performance is crucial to meeting the efficiency requirements of the spectrograph system. To accommodate VIRUS, the HET is undergoing a substantial wide-field upgrade to increase its field of view to 22' in diameter. The previous HET facility Low Resolution Spectrograph (LRS), which was directly fed by the telescope's previous spherical aberration corrector, must be removed from the prime focus instrument package as a result of the telescope upgrades and instead be fiber-coupled to the telescope focal plane. For a similar cost as modifying LRS to accommodate these changes, a new second generation instrument (LRS2) will be based on the VIRUS unit spectrograph. The design, operational concept, construction, and laboratory testing and characterization of LRS2 is the primary focus of this dissertation, which highlights the benefits of leveraging the large engineering investment, economies of scale, and laboratory and observatory infrastructure associated with the massively replicated VIRUS instrument. LRS2 will provide integral field spectroscopy for a seeing-limited field of 12" x 6". The multiplexed VIRUS framework facilitates broad wavelength coverage from 370 nm to 1.0 mum spread between two dual-channel spectrographs at a moderate spectral resolving power of R ≈ 2000. The design departures from VIRUS are presented, including the novel integral field unit, VPH grism dispersers, and various optical changes for accommodating the broadband wavelength coverage. Laboratory testing has verified that LRS2 largely meets its image quality specification and is nearly ready for delivery to the HET where its final verification and validation tasks will be executed. LRS2 will enable the continuation of most legacy LRS science programs and provide improved capability for future investigations. (Abstract shortened by ProQuest.).
-
Interaction between Flavivirus and Cytoskeleton during Virus Replication
Foo, Kar Yue; Chee, Hui-Yee
2015-01-01
Flaviviruses are potentially human pathogens that cause major epidemics worldwide. Flavivirus interacts with host cell factors to form a favourable virus replication site. Cell cytoskeletons have been observed to have close contact with flaviviruses, which expands the understanding of cytoskeleton functions during virus replication, although many detailed mechanisms are still unclear. The interactions between the virus and host cytoskeletons such as actin filaments, microtubules, and intermediate filaments have provided insight into molecular alterations during the virus infection, such as viral entry, in-cell transport, scaffold assembly, and egress. This review article focuses on the utilization of cytoskeleton by Flavivirus and the respective functions during virus replication. PMID:26347881
-
Purcell, M.K.; LaPatra, S.E.; Woodson, J.C.; Kurath, G.; Winton, J.R.
2010-01-01
The main objective of this study was to assess correlates of innate resistance in rainbow trout full-sibling families that differ in susceptibility to Infectious hematopoietic necrosis virus (IHNV). As part of a commercial breeding program, full-sibling families were challenged with IHNV by waterborne exposure at the 1 g size to determine susceptibility to IHNV. Progeny from select families (N = 7 families) that varied in susceptibility (ranging from 32 to 90% cumulative percent mortality (CPM)) were challenged again at the 10 g size by intra-peritoneal injection and overall mortality, early viral replication and immune responses were evaluated. Mortality challenges included 20–40 fish per family while viral replication and immune response studies included 6 fish per family at each time point (24, 48 and 72 h post-infection (hpi)). CPM at the 1 g size was significantly correlated with CPM at the 10 g size, indicating that inherent resistance was a stable trait irrespective of size. In the larger fish, viral load was measured by quantitative reverse-transcriptase PCR in the anterior kidney and was a significant predictor of family disease outcome at 48 hpi. Type I interferon (IFN) transcript levels were significantly correlated with an individual's viral load at 48 and 72 hpi, while type II IFN gene expression was significantly correlated with an individual's viral load at 24 and 48 hpi. Mean family type I but not type II IFN gene expression was weakly associated with susceptibility at 72 hpi. There was no association between mean family susceptibility and the constitutive expression of a range of innate immune genes (e.g. type I and II IFN pathway genes, cytokine and viral recognition receptor genes). The majority of survivors from the challenge had detectable serum neutralizing antibody titers but no trend was observed among families. This result suggests that even the most resistant families experienced sufficient levels of viral replication to trigger specific immunity. In summary, disease outcome for each family was determined very early in the infection process and resistance was associated with lower early viral replication.
-
Within-Host Evolution of Simian Arteriviruses in Crab-Eating Macaques
Moncla, Louise H.; Weiler, Andrea M.; Barry, Gabrielle; Weinfurter, Jason T.; Dinis, Jorge M.; Charlier, Olivia; Lauck, Michael; Bailey, Adam L.; Wahl-Jensen, Victoria; Nelson, Chase W.; Johnson, Joshua C.; Caì, Yíngyún; Goldberg, Tony L.; O'Connor, David H.; Jahrling, Peter B.
2016-01-01
ABSTRACT Simian arteriviruses are a diverse clade of viruses infecting captive and wild nonhuman primates. We recently reported that Kibale red colobus virus 1 (KRCV-1) causes a mild and self-limiting disease in experimentally infected crab-eating macaques, while simian hemorrhagic fever virus (SHFV) causes lethal viral hemorrhagic fever. Here we characterize how these viruses evolved during replication in cell culture and in experimentally infected macaques. During passage in cell culture, 68 substitutions that were localized in open reading frames (ORFs) likely associated with host cell entry and exit became fixed in the KRCV-1 genome. However, we did not detect any strong signatures of selection during replication in macaques. We uncovered patterns of evolution that were distinct from those observed in surveys of wild red colobus monkeys, suggesting that these species may exert different adaptive challenges for KRCV-1. During SHFV infection, we detected signatures of selection on ORF 5a and on a small subset of sites in the genome. Overall, our data suggest that patterns of evolution differ markedly among simian arteriviruses and among host species. IMPORTANCE Certain RNA viruses can cross species barriers and cause disease in new hosts. Simian arteriviruses are a diverse group of related viruses that infect captive and wild nonhuman primates, with associated disease severity ranging from apparently asymptomatic infections to severe, viral hemorrhagic fevers. We infected nonhuman primate cell cultures and then crab-eating macaques with either simian hemorrhagic fever virus (SHFV) or Kibale red colobus virus 1 (KRCV-1) and assessed within-host viral evolution. We found that KRCV-1 quickly acquired a large number of substitutions in its genome during replication in cell culture but that evolution in macaques was limited. In contrast, we detected selection focused on SHFV ORFs 5a and 5, which encode putative membrane proteins. These patterns suggest that in addition to diverse pathogenic phenotypes, these viruses may also exhibit distinct patterns of within-host evolution both in vitro and in vivo. PMID:27974564
-
van de Water, Sandra G. P.; Potgieter, Christiaan A.; van Rijn, Piet A.
2016-01-01
ABSTRACT The Reoviridae family consists of nonenveloped multilayered viruses with a double-stranded RNA genome consisting of 9 to 12 genome segments. The Orbivirus genus of the Reoviridae family contains African horse sickness virus (AHSV), bluetongue virus, and epizootic hemorrhagic disease virus, which cause notifiable diseases and are spread by biting Culicoides species. Here, we used reverse genetics for AHSV to study the role of outer capsid protein VP2, encoded by genome segment 2 (Seg-2). Expansion of a previously found deletion in Seg-2 indicates that structural protein VP2 of AHSV is not essential for virus replication in vitro. In addition, in-frame replacement of RNA sequences in Seg-2 by that of green fluorescence protein (GFP) resulted in AHSV expressing GFP, which further confirmed that VP2 is not essential for virus replication. In contrast to virus replication without VP2 expression in mammalian cells, virus replication in insect cells was strongly reduced, and virus release from insect cells was completely abolished. Further, the other outer capsid protein, VP5, was not copurified with virions for virus mutants without VP2 expression. AHSV without VP5 expression, however, could not be recovered, indicating that outer capsid protein VP5 is essential for virus replication in vitro. Our results demonstrate for the first time that a structural viral protein is not essential for orbivirus replication in vitro, which opens new possibilities for research on other members of the Reoviridae family. IMPORTANCE Members of the Reoviridae family cause major health problems worldwide, ranging from lethal diarrhea caused by rotavirus in humans to economic losses in livestock production caused by different orbiviruses. The Orbivirus genus contains many virus species, of which bluetongue virus, epizootic hemorrhagic disease virus, and African horse sickness virus (AHSV) cause notifiable diseases according to the World Organization of Animal Health. Recently, it has been shown that nonstructural proteins NS3/NS3a and NS4 are not essential for virus replication in vitro, whereas it is generally assumed that structural proteins VP1 to -7 of these nonenveloped, architecturally complex virus particles are essential. Here we demonstrate for the first time that structural protein VP2 of AHSV is not essential for virus replication in vitro. Our findings are very important for virologists working in the field of nonenveloped viruses, in particular reoviruses. PMID:27903804
-
Burden, J P; Griffiths, C M; Cory, J S; Smith, P; Sait, S M
2002-03-01
Knowledge of the mechanisms of pathogen persistence in relation to fluctuations in host density is crucial to our understanding of disease dynamics. In the case of insect baculoviruses, which are typically transmitted horizontally via a lifestage that can persist outside the host, a key issue that remains to be elucidated is whether the virus can also be transmitted vertically as a sublethal infection. We show that RNA transcripts for the Plodia interpunctella GV granulin gene are present in a high proportion of P. interpunctella insects that survive virus challenge. Granulin is a late-expressed gene that is only transcribed after viral genome replication, its presence thus strongly indicates that viral genome replication has occurred. Almost all insects surviving the virus challenge tested positive for viral RNA in the larval and pupal stage. However, this proportion declined in the emerging adults. Granulin mRNA was also detected in both the ovaries and testes, which may represent a putative mechanism by which reduced fecundity in sublethally affected hosts might be manifested. RNA transcripts were also detected in 60-80% of second-generation larvae that were derived from mating surviving adults, but there was no difference between the sexes, with both males and females capable of transmitting a sublethal infection to their offspring. The data indicate that low-level persistent infection, with at least limited gene expression, can occur in P. interpunctella following survival of a granulovirus challenge. We believe that this is the first demonstration of a persistent, sublethal infection by a baculovirus to be initiated by a sublethal virus dose. We hypothesize that the 'latent' baculovirus infections frequently referred to in the literature may also be low level persistent, sublethal infections resulting from survival from initial baculovirus exposure.
-
Replication of Many Human Viruses Is Refractory to Inhibition by Endogenous Cellular MicroRNAs
Bogerd, Hal P.; Skalsky, Rebecca L.; Kennedy, Edward M.; Furuse, Yuki; Whisnant, Adam W.; Flores, Omar; Schultz, Kimberly L. W.; Putnam, Nicole; Barrows, Nicholas J.; Sherry, Barbara; Scholle, Frank; Garcia-Blanco, Mariano A.; Griffin, Diane E.
2014-01-01
ABSTRACT The issue of whether viruses are subject to restriction by endogenous microRNAs (miRNAs) and/or by virus-induced small interfering RNAs (siRNAs) in infected human somatic cells has been controversial. Here, we address this question in two ways. First, using deep sequencing, we demonstrate that infection of human cells by the RNA virus dengue virus (DENV) or West Nile virus (WNV) does not result in the production of any virus-derived siRNAs or viral miRNAs. Second, to more globally assess the potential of small regulatory RNAs to inhibit virus replication, we used gene editing to derive human cell lines that lack a functional Dicer enzyme and that therefore are unable to produce miRNAs or siRNAs. Infection of these cells with a wide range of viruses, including DENV, WNV, yellow fever virus, Sindbis virus, Venezuelan equine encephalitis virus, measles virus, influenza A virus, reovirus, vesicular stomatitis virus, human immunodeficiency virus type 1, or herpes simplex virus 1 (HSV-1), failed to reveal any enhancement in the replication of any of these viruses, although HSV-1, which encodes at least eight Dicer-dependent viral miRNAs, did replicate somewhat more slowly in the absence of Dicer. We conclude that most, and perhaps all, human viruses have evolved to be resistant to inhibition by endogenous human miRNAs during productive replication and that dependence on a cellular miRNA, as seen with hepatitis C virus, is rare. How viruses have evolved to avoid inhibition by endogenous cellular miRNAs, which are generally highly conserved during metazoan evolution, remains to be determined. IMPORTANCE Eukaryotic cells express a wide range of small regulatory RNAs, including miRNAs, that have the potential to inhibit the expression of mRNAs that show sequence complementarity. Indeed, previous work has suggested that endogenous miRNAs have the potential to inhibit viral gene expression and replication. Here, we demonstrate that the replication of a wide range of pathogenic viruses is not enhanced in human cells engineered to be unable to produce miRNAs, indicating that viruses have evolved to be resistant to inhibition by miRNAs. This result is important, as it implies that manipulation of miRNA levels is not likely to prove useful in inhibiting virus replication. It also focuses attention on the question of how viruses have evolved to resist inhibition by miRNAs and whether virus mutants that have lost this resistance might prove useful, for example, in the development of attenuated virus vaccines. PMID:24807715
-
Virus reactivation: a panoramic view in human infections
Traylen, Christopher M; Patel, Hersh R; Fondaw, Wylder; Mahatme, Sheran; Williams, John F; Walker, Lia R; Dyson, Ossie F; Arce, Sergio; Akula, Shaw M
2011-01-01
Viruses are obligate intracellular parasites, relying to a major extent on the host cell for replication. An active replication of the viral genome results in a lytic infection characterized by the release of new progeny virus particles, often upon the lysis of the host cell. Another mode of virus infection is the latent phase, where the virus is ‘quiescent’ (a state in which the virus is not replicating). A combination of these stages, where virus replication involves stages of both silent and productive infection without rapidly killing or even producing excessive damage to the host cells, falls under the umbrella of a persistent infection. Reactivation is the process by which a latent virus switches to a lytic phase of replication. Reactivation may be provoked by a combination of external and/or internal cellular stimuli. Understanding this mechanism is essential in developing future therapeutic agents against viral infection and subsequent disease. This article examines the published literature and current knowledge regarding the viral and cellular proteins that may play a role in viral reactivation. The focus of the article is on those viruses known to cause latent infections, which include herpes simplex virus, varicella zoster virus, Epstein–Barr virus, human cytomegalovirus, human herpesvirus 6, human herpesvirus 7, Kaposi’s sarcoma-associated herpesvirus, JC virus, BK virus, parvovirus and adenovirus. PMID:21799704
-
A CRISPR toolbox to study virus–host interactions
Puschnik, Andreas S.; Majzoub, Karim; Ooi, Yaw Shin; Carette, Jan E.
2018-01-01
Viruses depend on their hosts to complete their replication cycles; they exploit cellular receptors for entry and hijack cellular functions to replicate their genome, assemble progeny virions and spread. Recently, genome-scale CRISPR–Cas screens have been used to identify host factors that are required for virus replication, including the replication of clinically relevant viruses such as Zika virus, West Nile virus, dengue virus and hepatitis C virus. In this Review, we discuss the technical aspects of genome-scale knockout screens using CRISPR–Cas technology, and we compare these screens with alternative genetic screening technologies. The relative ease of use and reproducibility of CRISPR–Cas make it a powerful tool for probing virus–host interactions and for identifying new antiviral targets. PMID:28420884
-
Ultrastructure of the replication sites of positive-strand RNA viruses
DOE Office of Scientific and Technical Information (OSTI.GOV)
Harak, Christian; Lohmann, Volker, E-mail: volker_lohmann@med.uni-heidelberg.de
2015-05-15
Positive strand RNA viruses replicate in the cytoplasm of infected cells and induce intracellular membranous compartments harboring the sites of viral RNA synthesis. These replication factories are supposed to concentrate the components of the replicase and to shield replication intermediates from the host cell innate immune defense. Virus induced membrane alterations are often generated in coordination with host factors and can be grouped into different morphotypes. Recent advances in conventional and electron microscopy have contributed greatly to our understanding of their biogenesis, but still many questions remain how viral proteins capture membranes and subvert host factors for their need. Inmore » this review, we will discuss different representatives of positive strand RNA viruses and their ways of hijacking cellular membranes to establish replication complexes. We will further focus on host cell factors that are critically involved in formation of these membranes and how they contribute to viral replication. - Highlights: • Positive strand RNA viruses induce massive membrane alterations. • Despite the great diversity, replication complexes share many similarities. • Host factors play a pivotal role in replication complex biogenesis. • Use of the same host factors by several viruses hints to similar functions.« less
-
Herbert, Rebecca; Baron, Jana; Batten, Carrie; Baron, Michael; Taylor, Geraldine
2014-02-26
Peste des petits ruminants virus (PPRV) is a morbillivirus that can cause severe disease in sheep and goats, characterised by pyrexia, pneumo-enteritis, and gastritis. The socio-economic burden of the disease is increasing in underdeveloped countries, with poor livestock keepers being affected the most. Current vaccines consist of cell-culture attenuated strains of PPRV, which induce a similar antibody profile to that induced by natural infection. Generation of a vaccine that enables differentiation of infected from vaccinated animals (DIVA) would benefit PPR control and eradication programmes, particularly in the later stages of an eradication campaign and for countries where the disease is not endemic. In order to create a vaccine that would enable infected animals to be distinguished from vaccinated ones (DIVA vaccine), we have evaluated the immunogenicity of recombinant fowlpox (FP) and replication-defective recombinant human adenovirus 5 (Ad), expressing PPRV F and H proteins, in goats. The Ad constructs induced higher levels of virus-specific and neutralising antibodies, and primed greater numbers of CD8+ T cells than the FP-vectored vaccines. Importantly, a single dose of Ad-H, with or without the addition of Ad expressing ovine granulocyte macrophage colony-stimulating factor and/or ovine interleukin-2, not only induced strong antibody and cell-mediated immunity but also completely protected goats against challenge with virulent PPRV, 4 months after vaccination. Replication-defective Ad-H therefore offers the possibility of an effective DIVA vaccine.
-
Engram, Jessica C; Dunham, Richard M; Makedonas, George; Vanderford, Thomas H; Sumpter, Beth; Klatt, Nichole R; Ratcliffe, Sarah J; Garg, Seema; Paiardini, Mirko; McQuoid, Monica; Altman, John D; Staprans, Silvija I; Betts, Michael R; Garber, David A; Feinberg, Mark B; Silvestri, Guido
2009-07-01
Our limited understanding of the interaction between primate lentiviruses and the host immune system complicates the design of an effective HIV/AIDS vaccine. To identify immunological correlates of protection from SIV disease progression, we immunized two groups of five rhesus macaques (RMs) with either modified vaccinia Ankara (MVA) or MVADeltaudg vectors that expressed SIVmac239 Gag and Tat. Both vectors raised a SIV-specific CD8(+) T cell response, with a magnitude that was greater in mucosal tissues than in peripheral blood. After challenge with SIVmac239, all vaccinated RMs showed mucosal and systemic CD8(+) T cell recall responses that appeared faster and were of greater magnitude than those in five unvaccinated control animals. All vaccinated RMs showed a approximately 1-log lower peak and early set-point SIV viral load than the unvaccinated animals, and then, by 8 wk postchallenge, exhibited levels of viremia similar to the controls. We observed a significant direct correlation between the magnitude of postchallenge SIV-specific CD8(+) T cell responses and SIV viral load. However, vaccinated RMs showed no protection from either systemic or mucosal CD4(+) T cell depletion and no improved survival. The observation that vaccine-induced, SIV-specific CD8(+) T cells that partially control SIVmac239 virus replication fail to protect from immunological or clinical progression of SIV infection underscores both the complexity of AIDS pathogenesis and the challenges of properly assessing the efficacy of candidate AIDS vaccines.
-
Replication-Deficient Particles: New Insights into the Next Generation of Bluetongue Virus Vaccines.
Celma, Cristina C; Stewart, Meredith; Wernike, Kerstin; Eschbaumer, Michael; Gonzalez-Molleda, Lorenzo; Breard, Emmanuel; Schulz, Claudia; Hoffmann, Bernd; Haegeman, Andy; De Clercq, Kris; Zientara, Stephan; van Rijn, Piet A; Beer, Martin; Roy, Polly
2017-01-01
Bluetongue virus (BTV) is endemic in many parts of the world, often causing severe hemorrhagic disease in livestock. To date, at least 27 different serotypes have been recognized. Vaccination against all serotypes is necessary to protect susceptible animals and to prevent onward spread of the virus by insect vectors. In our previous studies, we generated replication-deficient (disabled infectious single-cycle [DISC]) virus strains for a number of serotypes and reported preliminary data on their protective efficacy in animals. In this report, to advance the DISC vaccines to the marketplace, we investigated different parameters of these DISC vaccines. First, we demonstrated the genetic stabilities of these vaccine strains and also the complementing cell line. Subsequently, the optimal storage conditions of vaccines, including additives, temperature, and desiccation, were determined and their protective efficacies in animals confirmed. Furthermore, to test if mixtures of different vaccine strains could be tolerated, we tested cocktails of DISC vaccines in combinations of three or six different serotypes in sheep and cattle, the two natural hosts of BTV. Groups of sheep vaccinated with a cocktail of six different vaccines were completely protected from challenge with individual virulent serotypes, both in early challenge and after 5 months of challenge without any clinical disease. There was no interference in protection between the different vaccines. Protection was also achieved in cattle with a mixture of three vaccine strains, albeit at a lesser level than in sheep. Our data support and validate the suitability of these virus strains as the next-generation vaccines for BTV. Bluetongue (BT) is a debilitating and in many cases lethal disease that affects ruminants of economic importance. Classical vaccines that afford protection against bluetongue virus, the etiological agent, are not free from secondary and undesirable effects. A surge in new approaches to produce highly attenuated, safer vaccines was evident after the development of the BTV reverse-genetics system that allows the introduction of targeted mutations in the virus genome. We targeted an essential gene to develop disabled virus strains as vaccine candidates. The results presented in this report further substantiate our previous evidence and support the suitability of these virus strains as the next-generation BTV vaccines. Copyright © 2016 Celma et al.
-
Replication-Deficient Particles: New Insights into the Next Generation of Bluetongue Virus Vaccines
Celma, Cristina C.; Stewart, Meredith; Wernike, Kerstin; Eschbaumer, Michael; Gonzalez-Molleda, Lorenzo; Breard, Emmanuel; Schulz, Claudia; Hoffmann, Bernd; Haegeman, Andy; De Clercq, Kris; Zientara, Stephan; van Rijn, Piet A.; Beer, Martin
2016-01-01
ABSTRACT Bluetongue virus (BTV) is endemic in many parts of the world, often causing severe hemorrhagic disease in livestock. To date, at least 27 different serotypes have been recognized. Vaccination against all serotypes is necessary to protect susceptible animals and to prevent onward spread of the virus by insect vectors. In our previous studies, we generated replication-deficient (disabled infectious single-cycle [DISC]) virus strains for a number of serotypes and reported preliminary data on their protective efficacy in animals. In this report, to advance the DISC vaccines to the marketplace, we investigated different parameters of these DISC vaccines. First, we demonstrated the genetic stabilities of these vaccine strains and also the complementing cell line. Subsequently, the optimal storage conditions of vaccines, including additives, temperature, and desiccation, were determined and their protective efficacies in animals confirmed. Furthermore, to test if mixtures of different vaccine strains could be tolerated, we tested cocktails of DISC vaccines in combinations of three or six different serotypes in sheep and cattle, the two natural hosts of BTV. Groups of sheep vaccinated with a cocktail of six different vaccines were completely protected from challenge with individual virulent serotypes, both in early challenge and after 5 months of challenge without any clinical disease. There was no interference in protection between the different vaccines. Protection was also achieved in cattle with a mixture of three vaccine strains, albeit at a lesser level than in sheep. Our data support and validate the suitability of these virus strains as the next-generation vaccines for BTV. IMPORTANCE Bluetongue (BT) is a debilitating and in many cases lethal disease that affects ruminants of economic importance. Classical vaccines that afford protection against bluetongue virus, the etiological agent, are not free from secondary and undesirable effects. A surge in new approaches to produce highly attenuated, safer vaccines was evident after the development of the BTV reverse-genetics system that allows the introduction of targeted mutations in the virus genome. We targeted an essential gene to develop disabled virus strains as vaccine candidates. The results presented in this report further substantiate our previous evidence and support the suitability of these virus strains as the next-generation BTV vaccines. PMID:27795442
-
Parvovirus Minute Virus of Mice Induces a DNA Damage Response That Facilitates Viral Replication
Adeyemi, Richard O.; Landry, Sebastien; Davis, Meredith E.; Weitzman, Matthew D.; Pintel, David J.
2010-01-01
Infection by DNA viruses can elicit DNA damage responses (DDRs) in host cells. In some cases the DDR presents a block to viral replication that must be overcome, and in other cases the infecting agent exploits the DDR to facilitate replication. We find that low multiplicity infection with the autonomous parvovirus minute virus of mice (MVM) results in the activation of a DDR, characterized by the phosphorylation of H2AX, Nbs1, RPA32, Chk2 and p53. These proteins are recruited to MVM replication centers, where they co-localize with the main viral replication protein, NS1. The response is seen in both human and murine cell lines following infection with either the MVMp or MVMi strains. Replication of the virus is required for DNA damage signaling. Damage response proteins, including the ATM kinase, accumulate in viral-induced replication centers. Using mutant cell lines and specific kinase inhibitors, we show that ATM is the main transducer of the signaling events in the normal murine host. ATM inhibitors restrict MVM replication and ameliorate virus-induced cell cycle arrest, suggesting that DNA damage signaling facilitates virus replication, perhaps in part by promoting cell cycle arrest. Thus it appears that MVM exploits the cellular DNA damage response machinery early in infection to enhance its replication in host cells. PMID:20949077
-
Zaitseva, Marina; Thomas, Antonia; Meseda, Clement A; Cheung, Charles Y K; Diaz, Claudia G; Xiang, Yan; Crotty, Shane; Golding, Hana
2017-08-01
Bioluminescence imaging (BLI) was used to follow dissemination of recombinant vaccinia virus (VACV) expressing luciferase (IHD-J-Luc) in BALB/c nu/nu mice treated post-challenge with monoclonal antibodies (MAbs) against L1 and B5 VACV proteins in a model of Progressive Vaccinia (PV). Areas Under the flux Curve (AUC) were calculated for viral loads in multiple organs in individual mice. Following scarification with 10 5 pfu, IHD-J-Luc VACV undergoes fast replication at the injection site and disseminates rapidly to the inguinal lymph nodes followed by spleen, liver, and axillary lymph nodes within 2-3 days and before primary lesions are visible at the site of scarification. Extension of survival in nude mice treated with a combination of anti-B5 and anti-L1 MAbs 24 h post challenge correlated with a significant reduction in viral load at the site of scarification and delayed systemic dissemination. Nude mice reconstituted with 10 4 T cells prior to challenge with IHD-J-Luc, and treated with MAbs post-challenge, survived infection, cleared the virus from all organs and scarification site, and developed anti-VACV IgG and VACV-specific polyfunctional CD8 + T cells that co-expressed the degranulation marker CD107a, and IFNγ and TNFα cytokines. All T cell reconstituted mice survived intranasal re-challenge with IHD-J-Luc (10 4 pfu) two months after the primary infection. Thus, using BLI to monitor VACV replication in a PV model, we showed that anti-VACV MAbs administered post challenge extended survival of nude mice and protected T cell reconstituted nude mice from lethality by reducing replication at the site of scarification and systemic dissemination of VACV. Published by Elsevier B.V.
-
Quirin, Christina; Rohmer, Stanimira; Fernández-Ulibarri, Inés; Behr, Michael; Hesse, Andrea; Engelhardt, Sarah; Erbs, Philippe; Enk, Alexander H.
2011-01-01
Abstract Key challenges facing cancer therapy are the development of tumor-specific drugs and potent multimodal regimens. Oncolytic adenoviruses possess the potential to realize both aims by restricting virus replication to tumors and inserting therapeutic genes into the virus genome, respectively. A major effort in this regard is to express transgenes in a tumor-specific manner without affecting virus replication. Using both luciferase as a sensitive reporter and genetic prodrug activation, we show that promoter control of E1A facilitates highly selective expression of transgenes inserted into the late transcription unit. This, however, required multistep optimization of late transgene expression. Transgene insertion via internal ribosome entry site (IRES), splice acceptor (SA), or viral 2A sequences resulted in replication-dependent expression. Unexpectedly, analyses in appropriate substrates and with matching control viruses revealed that IRES and SA, but not 2A, facilitated indirect transgene targeting via tyrosinase promoter control of E1A. Transgene expression via SA was more selective (up to 1,500-fold) but less effective than via IRES. Notably, we also revealed transgene-dependent interference with splicing. Hence, the prodrug convertase FCU1 (a cytosine deaminase–uracil phosphoribosyltransferase fusion protein) was expressed only after optimizing the sequence surrounding the SA site and mutating a cryptic splice site within the transgene. The resulting tyrosinase promoter-regulated and FCU1-encoding adenovirus combined effective oncolysis with targeted prodrug activation therapy of melanoma. Thus, prodrug activation showed potent bystander killing and increased cytotoxicity of the virus up to 10-fold. We conclude that armed oncolytic viruses can be improved substantially by comparing and optimizing strategies for targeted transgene expression, thereby implementing selective and multimodal cancer therapies. PMID:20939692
-
Yang, Songtao; Xia, Xianzhu; Qiao, Jun; Liu, Quan; Chang, Shuang; Xie, Zhijing; Ju, Huiyan; Zou, Xiaohuan; Gao, Yuwei
2008-03-10
Feline panleukopenia virus (FPV) is an important infectious pathogen of all members of the family Felidae. Here, we describe construction of a replication-competent recombinant canine adenovirus type 2 (CAV-2) expressing the VP2 protein of FPV (CAV-2-VP2) by transfection of MDCK cells with recombinant CAV-2 genome carrying a VP2 expression cassette. Ten 3-month-old cats were vaccinated with the recombinant virus with two boosters at 15-day intervals. All cats developed neutralizing antibodies of titers 1:16-1:32 by day 15 post-primary vaccination, increasing to 1:64-1:128 by day 45. Examination for clinical signs and viral presence, and total white blood cell counts in peripheral blood following FPV challenge, showed that all were completely protected. This recombinant virus appears to provide an effective alternative to attenuated and inactivated vaccines in immunizing cats against feline panleukopenia.
-
Protein Interactions during the Flavivirus and Hepacivirus Life Cycle*
Bruening, Janina; Weigel, Bettina; Pietschmann, Thomas
2017-01-01
Protein–protein interactions govern biological functions in cells, in the extracellular milieu, and at the border between cells and extracellular space. Viruses are small intracellular parasites and thus rely on protein interactions to produce progeny inside host cells and to spread from cell to cell. Usage of host proteins by viruses can have severe consequences e.g. apoptosis, metabolic disequilibria, or altered cell proliferation and mobility. Understanding protein interactions during virus infection can thus educate us on viral infection and pathogenesis mechanisms. Moreover, it has led to important clinical translations, including the development of new therapeutic and vaccination strategies. Here, we will discuss protein interactions of members of the Flaviviridae family, which are small enveloped RNA viruses. Dengue virus, Zika virus and hepatitis C virus belong to the most prominent human pathogenic Flaviviridae. With a genome of roughly ten kilobases encoding only ten viral proteins, Flaviviridae display intricate mechanisms to engage the host cell machinery for their purpose. In this review, we will highlight how dengue virus, hepatitis C virus, Japanese encephalitis virus, tick-borne encephalitis virus, West Nile virus, yellow fever virus, and Zika virus proteins engage host proteins and how this knowledge helps elucidate Flaviviridae infection. We will specifically address the protein composition of the virus particle as well as the protein interactions during virus entry, replication, particle assembly, and release from the host cell. Finally, we will give a perspective on future challenges in Flaviviridae interaction proteomics and why we believe these challenges should be met. PMID:28077444
-
Development of a genetic system for the archaeal virus Sulfolobus turreted icosahedral virus (STIV).
Wirth, Jennifer Fulton; Snyder, Jamie C; Hochstein, Rebecca A; Ortmann, Alice C; Willits, Deborah A; Douglas, Trevor; Young, Mark J
2011-06-20
Our understanding of archaeal viruses has been limited by the lack of genetic systems for examining viral function. We describe the construction of an infectious clone for the archaeal virus Sulfolobus turreted icosahedral virus (STIV). STIV was isolated from a high temperature (82°C) acidic (pH 2.2) hot spring in Yellowstone National Park and replicates in the archaeal model organism Sulfolobus solfataricus (Rice et al., 2004). While STIV is one of most studied archaeal viruses, little is known about its replication cycle. The development of an STIV infectious clone allows for directed gene disruptions and detailed genetic analysis of the virus. The utility of the STIV infectious clone was demonstrated by gene disruption of STIV open reading frame (ORF) B116 which resulted in crippled virus replication, while disruption of ORFs A197, C381 and B345 was lethal for virus replication. Copyright © 2011. Published by Elsevier Inc.
-
Influenza virus replication in macrophages: balancing protection and pathogenesis
Beck, Donald; Bianchini, Elizabeth
2017-01-01
Macrophages are essential for protection against influenza A virus infection, but are also implicated in the morbidity and mortality associated with severe influenza disease, particularly during infection with highly pathogenic avian influenza (HPAI) H5N1 virus. While influenza virus infection of macrophages was once thought to be abortive, it is now clear that certain virus strains can replicate productively in macrophages. This may have important consequences for the antiviral functions of macrophages, the course of disease and the outcome of infection for the host. In this article, we review findings related to influenza virus replication in macrophages and the impact of productive replication on macrophage antiviral functions. A clear understanding of the interactions between influenza viruses and macrophages may lead to new antiviral therapies to relieve the burden of severe disease associated with influenza viruses. PMID:28884667
-
Martins, Mauricio A; Wilson, Nancy A; Piaskowski, Shari M; Weisgrau, Kim L; Furlott, Jessica R; Bonaldo, Myrna C; Veloso de Santana, Marlon G; Rudersdorf, Richard A; Rakasz, Eva G; Keating, Karen D; Chiuchiolo, Maria J; Piatak, Michael; Allison, David B; Parks, Christopher L; Galler, Ricardo; Lifson, Jeffrey D; Watkins, David I
2014-07-01
Broadly targeted cellular immune responses are thought to be important for controlling replication of human and simian immunodeficiency viruses (HIV and SIV). However, eliciting such responses by vaccination is complicated by immunodominance, the preferential targeting of only a few of the many possible epitopes of a given antigen. This phenomenon may be due to the coexpression of dominant and subdominant epitopes by the same antigen-presenting cell and may be overcome by distributing these sequences among several different vaccine constructs. Accordingly, we tested whether vaccinating rhesus macaques with "minigenes" encoding fragments of Gag, Vif, and Nef resulted in broadened cellular responses capable of controlling SIV replication. We delivered these minigenes through combinations of recombinant Mycobacterium bovis BCG (rBCG), electroporated recombinant DNA (rDNA) along with an interleukin-12 (IL-12)-expressing plasmid (EP rDNA plus pIL-12), yellow fever vaccine virus 17D (rYF17D), and recombinant adenovirus serotype 5 (rAd5). Although priming with EP rDNA plus pIL-12 increased the breadth of vaccine-induced T-cell responses, this effect was likely due to the improved antigen delivery afforded by electroporation rather than modulation of immunodominance. Indeed, Mamu-A*01(+) vaccinees mounted CD8(+) T cells directed against only one subdominant epitope, regardless of the vaccination regimen. After challenge with SIVmac239, vaccine efficacy was limited to a modest reduction in set point in some of the groups and did not correlate with standard T-cell measurements. These findings suggest that broad T-cell responses elicited by conventional vectors may not be sufficient to substantially contain AIDS virus replication. Immunodominance poses a major obstacle to the generation of broadly targeted, HIV-specific cellular responses by vaccination. Here we attempted to circumvent this phenomenon and thereby broaden the repertoire of SIV-specific cellular responses by vaccinating rhesus macaques with minigenes encoding fragments of Gag, Vif, and Nef. In contrast to previous mouse studies, this strategy appeared to minimally affect monkey CD8(+) T-cell immundominance hierarchies, as seen by the detection of only one subdominant epitope in Mamu-A*01(+) vaccinees. This finding underscores the difficulty of inducing subdominant CD8(+) T cells by vaccination and demonstrates that strategies other than gene fragmentation may be required to significantly alter immunodominance in primates. Although some of the regimens tested here were extremely immunogenic, vaccine efficacy was limited to a modest reduction in set point viremia after challenge with SIVmac239. No correlates of protection were identified. These results reinforce the notion that vaccine immunogenicity does not predict control of AIDS virus replication. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
-
Lee, Sang-Won; Markham, Philip F; Coppo, Mauricio J C; Legione, Alistair R; Shil, Niraj K; Quinteros, José A; Noormohammadi, Amir H; Browning, Glenn F; Hartley, Carol A; Devlin, Joanne M
2014-03-01
Recent phylogenetic studies have identified different genotypic lineages of infectious laryngotracheitis virus (ILTV), and these lineages can recombine in the field. The emergence of virulent recombinant field strains of ILTV by natural recombination between commercial vaccines belonging to different genotypic lineages has been reported recently. Despite the use of attenuated ILTV vaccines, these recombinant viruses were able to spread and cause disease in commercial poultry flocks, raising the question of whether the different lineages of ILTV can induce cross-protective immune responses. This study examined the capacity of the Australian-origin A20 ILTV vaccine to protect against challenge with the class 8 ILTV recombinant virus, the genome of which is predominantly derived from a heterologous genotypic lineage. Following challenge, birds vaccinated via eyedrop were protected from clinical signs of disease and pathological changes in the tracheal mucosa, although they were not completely protected from viral infection or replication. In contrast, the challenge virus induced severe clinical signs and tracheal pathology in unvaccinated birds. This is the first study to examine the ability of a vaccine from the Australian lineage to protect against challenge with a virus from a heterologous lineage. These results suggest that the two distinct genotypic lineages of ILTV can both induce cross-protection, indicating that current commercial vaccines are still likely to assist in control of ILTV in the poultry industry, in spite of the emergence of novel recombinants derived from different genotypic lineages.
-
Lihoradova, Olga A.; Indran, Sabarish V.; Kalveram, Birte; Lokugamage, Nandadeva; Head, Jennifer A.; Gong, Bin; Tigabu, Bersabeh; Juelich, Terry L.; Freiberg, Alexander N.; Ikegami, Tetsuro
2013-01-01
Rift Valley fever virus (RVFV; genus Phlebovirus, family Bunyaviridae) is a mosquito-borne zoonotic pathogen which can cause hemorrhagic fever, neurological disorders or blindness in humans, and a high rate of abortion in ruminants. MP-12 strain, a live-attenuated candidate vaccine, is attenuated in the M- and L-segments, but the S-segment retains the virulent phenotype. MP-12 was manufactured as an Investigational New Drug vaccine by using MRC-5 cells and encodes a functional NSs gene, the major virulence factor of RVFV which 1) induces a shutoff of the host transcription, 2) inhibits interferon (IFN)-β promoter activation, and 3) promotes the degradation of dsRNA-dependent protein kinase (PKR). MP-12 lacks a marker for differentiation of infected from vaccinated animals (DIVA). Although MP-12 lacking NSs works for DIVA, it does not replicate efficiently in type-I IFN-competent MRC-5 cells, while the use of type-I IFN-incompetent cells may negatively affect its genetic stability. To generate modified MP-12 vaccine candidates encoding a DIVA marker, while still replicating efficiently in MRC-5 cells, we generated recombinant MP-12 encoding Punta Toro virus Adames strain NSs (rMP12-PTNSs) or Sandfly fever Sicilian virus NSs (rMP12-SFSNSs) in place of MP-12 NSs. We have demonstrated that those recombinant MP-12 viruses inhibit IFN-β mRNA synthesis, yet do not promote the degradation of PKR. The rMP12-PTNSs, but not rMP12-SFSNSs, replicated more efficiently than recombinant MP-12 lacking NSs in MRC-5 cells. Mice vaccinated with rMP12-PTNSs or rMP12-SFSNSs induced neutralizing antibodies at a level equivalent to those vaccinated with MP-12, and were efficiently protected from wild-type RVFV challenge. The rMP12-PTNSs and rMP12-SFSNSs did not induce antibodies cross-reactive to anti-RVFV NSs antibody and are therefore applicable to DIVA. Thus, rMP12-PTNSs is highly efficacious, replicates efficiently in MRC-5 cells, and encodes a DIVA marker, all of which are important for vaccine development for Rift Valley fever. PMID:23638202
-
Lihoradova, Olga A; Indran, Sabarish V; Kalveram, Birte; Lokugamage, Nandadeva; Head, Jennifer A; Gong, Bin; Tigabu, Bersabeh; Juelich, Terry L; Freiberg, Alexander N; Ikegami, Tetsuro
2013-01-01
Rift Valley fever virus (RVFV; genus Phlebovirus, family Bunyaviridae) is a mosquito-borne zoonotic pathogen which can cause hemorrhagic fever, neurological disorders or blindness in humans, and a high rate of abortion in ruminants. MP-12 strain, a live-attenuated candidate vaccine, is attenuated in the M- and L-segments, but the S-segment retains the virulent phenotype. MP-12 was manufactured as an Investigational New Drug vaccine by using MRC-5 cells and encodes a functional NSs gene, the major virulence factor of RVFV which 1) induces a shutoff of the host transcription, 2) inhibits interferon (IFN)-β promoter activation, and 3) promotes the degradation of dsRNA-dependent protein kinase (PKR). MP-12 lacks a marker for differentiation of infected from vaccinated animals (DIVA). Although MP-12 lacking NSs works for DIVA, it does not replicate efficiently in type-I IFN-competent MRC-5 cells, while the use of type-I IFN-incompetent cells may negatively affect its genetic stability. To generate modified MP-12 vaccine candidates encoding a DIVA marker, while still replicating efficiently in MRC-5 cells, we generated recombinant MP-12 encoding Punta Toro virus Adames strain NSs (rMP12-PTNSs) or Sandfly fever Sicilian virus NSs (rMP12-SFSNSs) in place of MP-12 NSs. We have demonstrated that those recombinant MP-12 viruses inhibit IFN-β mRNA synthesis, yet do not promote the degradation of PKR. The rMP12-PTNSs, but not rMP12-SFSNSs, replicated more efficiently than recombinant MP-12 lacking NSs in MRC-5 cells. Mice vaccinated with rMP12-PTNSs or rMP12-SFSNSs induced neutralizing antibodies at a level equivalent to those vaccinated with MP-12, and were efficiently protected from wild-type RVFV challenge. The rMP12-PTNSs and rMP12-SFSNSs did not induce antibodies cross-reactive to anti-RVFV NSs antibody and are therefore applicable to DIVA. Thus, rMP12-PTNSs is highly efficacious, replicates efficiently in MRC-5 cells, and encodes a DIVA marker, all of which are important for vaccine development for Rift Valley fever.
-
Kazlauskas, Darius; Krupovic, Mart; Venclovas, Česlovas
2016-01-01
Abstract Genomic DNA replication is a complex process that involves multiple proteins. Cellular DNA replication systems are broadly classified into only two types, bacterial and archaeo-eukaryotic. In contrast, double-stranded (ds) DNA viruses feature a much broader diversity of DNA replication machineries. Viruses differ greatly in both completeness and composition of their sets of DNA replication proteins. In this study, we explored whether there are common patterns underlying this extreme diversity. We identified and analyzed all major functional groups of DNA replication proteins in all available proteomes of dsDNA viruses. Our results show that some proteins are common to viruses infecting all domains of life and likely represent components of the ancestral core set. These include B-family polymerases, SF3 helicases, archaeo-eukaryotic primases, clamps and clamp loaders of the archaeo-eukaryotic type, RNase H and ATP-dependent DNA ligases. We also discovered a clear correlation between genome size and self-sufficiency of viral DNA replication, the unanticipated dominance of replicative helicases and pervasive functional associations among certain groups of DNA replication proteins. Altogether, our results provide a comprehensive view on the diversity and evolution of replication systems in the DNA virome and uncover fundamental principles underlying the orchestration of viral DNA replication. PMID:27112572
-
Moyo, Buhle; Bloom, Kristie; Scott, Tristan; Ely, Abdullah; Arbuthnot, Patrick
2018-01-15
Chronic infections with hepatitis B and hepatitis C viruses (HBV and HCV) account for the majority of cases of cirrhosis and hepatocellular carcinoma. Current therapies for the infections have limitations and improved efficacy is necessary to prevent complications in carriers of the viruses. In the case of HBV persistence, the replication intermediate comprising covalently closed circular DNA (cccDNA) is particularly problematic. Licensed therapies have little effect on cccDNA and HBV replication relapses following treatment withdrawal. Disabling cccDNA is thus key to curing HBV infections and application of gene editing technology, such as harnessing the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) system, has curative potential. Several studies have reported good efficacy when employing CRISPR/Cas technologies to disable HBV replication in cultured cells and in hydrodynamically injected mice. Recent advances with HCV drug development have revolutionized treatment of the infection. Nevertheless, individuals may be refractory to treatment. Targeting RNA from HCV with CRISPR/Cas isolated from Francisella novicida may have therapeutic utility. Although preclinical work shows that CRISPR/Cas technology has potential to overcome infection with HBV and HCV, significant challenges need to be met. Ensuring specificity for viral targets and efficient delivery of the gene editing sequences to virus-infected cells are particularly important. The field is at an interesting stage and the future of curative antiviral drug regimens, particularly for treatment of chronic HBV infection, may well entail use of combinations that include derivatives of CRISPR/Cas. Copyright © 2017 Elsevier B.V. All rights reserved.
-
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 that block replication of seasonal IAV, but not HPAI, in macrophages. PMID:26423941
-
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 replication of seasonal IAV, but not HPAI, in macrophages. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
-
Jones, Frank R.; Gabitzsch, Elizabeth S.; Xu, Younong; Balint, Joseph P.; Borisevich, Viktoriya; Smith, Jennifer; Smith, Jeanon; Peng, Bi-Hung; Walker, Aida; Salazar, Magda; Paessler, Slobodan
2013-01-01
Vaccines against emerging pathogens such as the 2009 H1N1 pandemic virus can benefit from current technologies such as rapid genomic sequencing to construct the most biologically relevant vaccine. A novel platform (Ad5 [E1-, E2b-]) has been utilized to induce immune responses to various antigenic targets. We employed this vector platform to express hemagglutinin (HA) and neuraminidase (NA) genes from 2009 H1N1 pandemic viruses. Inserts were consensuses sequences designed from viral isolate sequences and the vaccine was rapidly constructed and produced. Vaccination induced H1N1 immune responses in mice, which afforded protection from lethal virus challenge. In ferrets, vaccination protected from disease development and significantly reduced viral titers in nasal washes. H1N1 cell mediated immunity as well as antibody induction correlated with the prevention of disease symptoms and reduction of virus replication. The Ad5 [E1-, E2b-] should be evaluated for the rapid development of effective vaccines against infectious diseases. PMID:21821082
-
Tsetsarkin, Konstantin A; Liu, Guangping; Kenney, Heather; Hermance, Meghan; Thangamani, Saravanan; Pletnev, Alexander G
2016-09-13
Tick-borne viruses include medically important zoonotic pathogens that can cause life-threatening diseases. Unlike mosquito-borne viruses, whose impact can be restrained via mosquito population control programs, for tick-borne viruses only vaccination remains the reliable means of disease prevention. For live vaccine viruses a concern exists, that spillovers from viremic vaccinees could result in introduction of genetically modified viruses into sustainable tick-vertebrate host transmission cycle in nature. To restrict tick-borne flavivirus (Langat virus, LGTV) vector tropism, we inserted target sequences for tick-specific microRNAs (mir-1, mir-275 and mir-279) individually or in combination into several distant regions of LGTV genome. This caused selective attenuation of viral replication in tick-derived cells. LGTV expressing combinations of target sequences for tick- and vertebrate CNS-specific miRNAs were developed. The resulting viruses replicated efficiently and remained stable in simian Vero cells, which do not express these miRNAs, however were severely restricted to replicate in tick-derived cells. In addition, simultaneous dual miRNA targeting led to silencing of virus replication in live Ixodes ricinus ticks and abolished virus neurotropism in highly permissive newborn mice. The concurrent restriction of adverse replication events in vertebrate and invertebrate hosts will, therefore, ensure the environmental safety of live tick-borne virus vaccine candidates.
-
IFITM3 restricts the morbidity and mortality associated with influenza.
Everitt, Aaron R; Clare, Simon; Pertel, Thomas; John, Sinu P; Wash, Rachael S; Smith, Sarah E; Chin, Christopher R; Feeley, Eric M; Sims, Jennifer S; Adams, David J; Wise, Helen M; Kane, Leanne; Goulding, David; Digard, Paul; Anttila, Verneri; Baillie, J Kenneth; Walsh, Tim S; Hume, David A; Palotie, Aarno; Xue, Yali; Colonna, Vincenza; Tyler-Smith, Chris; Dunning, Jake; Gordon, Stephen B; Smyth, Rosalind L; Openshaw, Peter J; Dougan, Gordon; Brass, Abraham L; Kellam, Paul
2012-03-25
The 2009 H1N1 influenza pandemic showed the speed with which a novel respiratory virus can spread and the ability of a generally mild infection to induce severe morbidity and mortality in a subset of the population. Recent in vitro studies show that the interferon-inducible transmembrane (IFITM) protein family members potently restrict the replication of multiple pathogenic viruses. Both the magnitude and breadth of the IFITM proteins' in vitro effects suggest that they are critical for intrinsic resistance to such viruses, including influenza viruses. Using a knockout mouse model, we now test this hypothesis directly and find that IFITM3 is essential for defending the host against influenza A virus in vivo. Mice lacking Ifitm3 display fulminant viral pneumonia when challenged with a normally low-pathogenicity influenza virus, mirroring the destruction inflicted by the highly pathogenic 1918 'Spanish' influenza. Similar increased viral replication is seen in vitro, with protection rescued by the re-introduction of Ifitm3. To test the role of IFITM3 in human influenza virus infection, we assessed the IFITM3 alleles of individuals hospitalized with seasonal or pandemic influenza H1N1/09 viruses. We find that a statistically significant number of hospitalized subjects show enrichment for a minor IFITM3 allele (SNP rs12252-C) that alters a splice acceptor site, and functional assays show the minor CC genotype IFITM3 has reduced influenza virus restriction in vitro. Together these data reveal that the action of a single intrinsic immune effector, IFITM3, profoundly alters the course of influenza virus infection in mouse and humans.
-
Ammayappan, Arun; Kurath, Gael; Thompson, Tarin M.; Vakharia, Vikram N.
2011-01-01
Viral hemorrhagic septicemia virus (VHSV), belonging to the genus Novirhabdovirus in the family of Rhabdoviridae, causes a highly contagious disease of fresh and saltwater fish worldwide. Recently, a novel genotype of VHSV, designated IVb, has invaded the Great Lakes in North America, causing large-scale epidemics in wild fish. An efficient reverse genetics system was developed to generate a recombinant VHSV of genotype IVb from cloned cDNA. The recombinant VHSV (rVHSV) was comparable to the parental wild-type strain both in vitro and in vivo, causing high mortality in yellow perch (Perca flavescens). A modified recombinant VHSV was generated in which the NV gene was substituted with an enhanced green fluorescent protein gene (rVHSV-ΔNV-EGFP), and another recombinant was made by inserting the EGFP gene into the full-length viral clone between the P and M genes (rVHSV-EGFP). The in vitro replication kinetics of rVHSV-EGFP was similar to rVHSV; however, the rVHSV-ΔNV-EGFP grew 2 logs lower. In yellow perch challenges, wtVHSV and rVHSV induced 82-100% cumulative per cent mortality (CPM), respectively, whereas rVHSV-EGFP produced 62% CPM and rVHSV-ΔNV-EGFP caused only 15% CPM. No reversion of mutation was detected in the recovered viruses and the recombinant viruses stably maintained the foreign gene after several passages. These results indicate that the NV gene of VHSV is not essential for viral replication in vitro and in vivo, but it plays an important role in viral replication efficiency and pathogenicity. This system will facilitate studies of VHSV replication, virulence, and production of viral vectored vaccines.
-
Sun, Yongke; Yang, Yuai; Zheng, Huanli; Xi, Dongmei; Lin, Mingxing; Zhang, Xiaomin; Yang, Linfu; Yan, Yulin; Chu, Xiaohui; Bi, Baoliang
2013-04-01
The objective of this study was to construct a recombinant adenovirus for future CSFV vaccines used in the pig industry for the reduction of losses involved in CSF outbreaks. The Erns and E2 genes of classical swine fever virus (CSFV), which encode the two main protective glycoproteins from the "Shimen" strain of CSFV, were combined and inserted into the replication-defective human adenovirus type-5 and named the rAd-Erns-E2. Nine pigs were randomly assigned to three treatment groups (three pigs in each group) including the rAd-Erns-E2, hAd-CMV control and DMEM control. Intramuscular vaccination with 2×10(6) TCID(50) of the rAd-Erns-E2 was administered two times with an interval of 21 days. At 42 days post inoculation, pigs in all groups were challenged with a lethal dose of 1×10(3) TCID(50) CSFV "Shimen" strain. Observation of clinical signs was made and the existence of CSFV RNA was detected. Animals in the hAd-CMV and DMEM groups showed severe clinical CSF symptoms and were euthanized from 7 to 10 days after the challenge. However, no adverse clinical CSF signs were observed in vaccinated pigs after the administration of rAd-Erns-E2 and even after CSFV challenge. Neither CSFV RNA nor pathological changes were detected in the tissues of interest of the above vaccinated pigs. These results implied that the recombination adenovirus carrying the Erns-E2 genes could be used to prevent swine from classical swine fever. Copyright © 2012 Elsevier Ltd. All rights reserved.
-
Filovirus pathogenesis and immune evasion: insights from Ebola virus and Marburg virus
Messaoudi, Ilhem; Amarasinghe, Gaya K.; Basler, Christopher F.
2016-01-01
Ebola viruses and Marburg viruses, members of the filovirus family, are zoonotic pathogens that cause severe disease in people. The Ebola virus epidemic in West Africa, which was first recognized in early 2014, highlights the threat posed by these deadly viruses. Filovirus disease is characterized by uncontrolled virus replication and the activation of damaging host pathways. Underlying these phenomena is the potent suppression of host innate antiviral responses, particularly the type I interferon (IFN) response, which allows high levels of replication. Here we review the mechanisms deployed by filoviruses to block host innate immunity and discuss aspects of virus replication that promote disease. PMID:26439085
-
Friendly fire: redirecting herpes simplex virus-1 for therapeutic applications.
Advani, S J; Weichselbaum, R R; Whitley, R J; Roizman, B
2002-09-01
Herpes simplex virus-1 (HSV-1) is a relatively large double-stranded DNA virus encoding at least 89 proteins with well characterized disease pathology. An understanding of the functions of viral proteins together with the ability to genetically engineer specific viral mutants has led to the development of attenuated HSV-1 for gene therapy. This review highlights the progress in creating attenuated genetically engineered HSV-1 mutants that are either replication competent (viral non-essential gene deleted) or replication defective (viral essential gene deleted). The choice between a replication-competent or -defective virus is based on the end-goal of the therapeutic intervention. Replication-competent HSV-1 mutants have primarily been employed as antitumor oncolytic viruses, with the lytic nature of the virus harnessed to destroy tumor cells selectively. In replacement gene therapy, replication-defective viruses have been utilized as delivery vectors. The advantages of HSV-1 vectors are that they infect quiescent and dividing cells efficiently and can encode for relatively large transgenes.
-
Molecular Studies of HTLV-1 Replication: An Update
Martin, Jessica L.; Maldonado, José O.; Mueller, Joachim D.; Zhang, Wei; Mansky, Louis M.
2016-01-01
Human T-cell leukemia virus type 1 (HTLV-1) was the first human retrovirus discovered. Studies on HTLV-1 have been instrumental for our understanding of the molecular pathology of virus-induced cancers. HTLV-1 is the etiological agent of an adult T-cell leukemia (ATL) and can lead to a variety of neurological pathologies, including HTLV-1-associated-myelopathy/tropical spastic paraparesis (HAM/TSP). The ability to treat the aggressive ATL subtypes remains inadequate. HTLV-1 replicates by (1) an infectious cycle involving virus budding and infection of new permissive target cells and (2) mitotic division of cells harboring an integrated provirus. Virus replication initiates host antiviral immunity and the checkpoint control of cell proliferation, but HTLV-1 has evolved elegant strategies to counteract these host defense mechanisms to allow for virus persistence. The study of the molecular biology of HTLV-1 replication has provided crucial information for understanding HTLV-1 replication as well as aspects of viral replication that are shared between HTLV-1 and human immunodeficiency virus type 1 (HIV-1). Here in this review, we discuss the various stages of the virus replication cycle—both foundational knowledge as well as current updates of ongoing research that is important for understanding HTLV-1 molecular pathogenesis as well as in developing novel therapeutic strategies. PMID:26828513
-
Ou, Horng D.; May, Andrew P.
2010-01-01
One of the greatest challenges in biomedicine is to define the critical targets and network interactions that are subverted to elicit growth deregulation in human cells. Understanding and developing rational treatments for cancer requires a definition of the key molecular targets and how they interact to elicit the complex growth deregulation phenotype. Viral proteins provide discerning and powerful probes to understand both how cells work and how they can be manipulated using a minimal number of components. The small DNA viruses have evolved to target inherent weaknesses in cellular protein interaction networks to hijack the cellular DNA and protein replication machinery. In the battle to escape the inevitability of senescence and programmed cell death, cancers have converged on similar mechanisms, through the acquisition and selection of somatic mutations that drive unchecked cellular replication in tumors. Understanding the dynamic mechanisms through which a minimal number of viral proteins promote host cells to undergo unscheduled and pathological replication is a powerful strategy to identify critical targets that are also disrupted in cancer. Viruses can therefore be used as tools to probe the system-wide protein-protein interactions and structures that drive growth deregulation in human cells. Ultimately this can provide a path for developing system context-dependent therapeutics. This review will describe ongoing experimental approaches using viruses to study pathways deregulated in cancer, with a particular focus on viral cellular protein-protein interactions and structures. PMID:21061422
-
Hsiang, Tien-Ying; Zhou, Ligang; Krug, Robert M
2012-10-01
We demonstrate that phosphorylation of the NS1 protein of a human influenza A virus occurs not only at the threonine (T) at position 215 but also at serines (Ss), specifically at positions 42 and 48. By generating recombinant influenza A/Udorn/72 (Ud) viruses that encode mutant NS1 proteins, we determined the roles of these phosphorylations in virus replication. At position 215 only a T-to-A substitution attenuated replication, whereas other substitutions (T to E to mimic constitutive phosphorylation, T to N, and T to P, the amino acid in avian influenza A virus NS1 proteins) had no effect. We conclude that attenuation resulting from the T-to-A substitution at position 215 is attributable to a deleterious structural change in the NS1 protein that is not caused by other amino acid substitutions and that phosphorylation of T215 does not affect virus replication. At position 48 neither an S-to-A substitution nor an S-to-D substitution that mimics constitutive phosphorylation affected virus replication. In contrast, at position 42, an S-to-D, but not an S-to-A, substitution caused attenuation. The S-to-D substitution eliminates detectable double-stranded RNA binding by the NS1 protein, accounting for attenuation of virus replication. We show that protein kinase C α (PKCα) catalyzes S42 phosphorylation. Consequently, the only phosphorylation of the NS1 protein of this human influenza A virus that regulates its replication is S42 phosphorylation catalyzed by PKCα. In contrast, phosphorylation of Ts or Ss in the NS1 protein of the 2009 H1N1 pandemic virus was not detected, indicating that NS1 phosphorylation probably does not play any role in the replication of this virus.
-
Virus-Like-Vaccines against HIV
Andersson, Anne-Marie C.; Schwerdtfeger, Melanie; Holst, Peter J.
2018-01-01
Protection against chronic infections has necessitated the development of ever-more potent vaccination tools. HIV seems to be the most challenging foe, with a remarkable, poorly immunogenic and fragile surface glycoprotein and the ability to overpower the cell immune system. Virus-like-particle (VLP) vaccines have emerged as potent inducers of antibody and helper T cell responses, while replication-deficient viral vectors have yielded potent cytotoxic T cell responses. Here, we review the emerging concept of merging these two technologies into virus-like-vaccines (VLVs) for the targeting of HIV. Such vaccines are immunologically perceived as viruses, as they infect cells and produce VLPs in situ, but they only resemble viruses, as the replication defective vectors and VLPs cannot propagate an infection. The inherent safety of such a platform, despite robust particle production, is a distinct advantage over live-attenuated vaccines that must balance safety and immunogenicity. Previous studies have delivered VLVs encoded in modified Vaccinia Ankara vectors and we have developed the concept into a single-reading adenovirus-based technology capable of eliciting robust CD8+ and CD4+ T cells responses and trimer binding antibody responses. Such vaccines offer the potential to display the naturally produced immunogen directly and induce an integrated humoral and cellular immune response. PMID:29439476
-
Virus-Like-Vaccines against HIV.
Andersson, Anne-Marie C; Schwerdtfeger, Melanie; Holst, Peter J
2018-02-11
Protection against chronic infections has necessitated the development of ever-more potent vaccination tools. HIV seems to be the most challenging foe, with a remarkable, poorly immunogenic and fragile surface glycoprotein and the ability to overpower the cell immune system. Virus-like-particle (VLP) vaccines have emerged as potent inducers of antibody and helper T cell responses, while replication-deficient viral vectors have yielded potent cytotoxic T cell responses. Here, we review the emerging concept of merging these two technologies into virus-like-vaccines (VLVs) for the targeting of HIV. Such vaccines are immunologically perceived as viruses, as they infect cells and produce VLPs in situ, but they only resemble viruses, as the replication defective vectors and VLPs cannot propagate an infection. The inherent safety of such a platform, despite robust particle production, is a distinct advantage over live-attenuated vaccines that must balance safety and immunogenicity. Previous studies have delivered VLVs encoded in modified Vaccinia Ankara vectors and we have developed the concept into a single-reading adenovirus-based technology capable of eliciting robust CD8⁺ and CD4⁺ T cells responses and trimer binding antibody responses. Such vaccines offer the potential to display the naturally produced immunogen directly and induce an integrated humoral and cellular immune response.
-
Arthos, James; Rubbert, Andrea; Rabin, Ronald L.; Cicala, Claudia; Machado, Elizabeth; Wildt, Kathryne; Hanbach, Meredith; Steenbeke, Tavis D.; Swofford, Ruth; Farber, Joshua M.; Fauci, Anthony S.
2000-01-01
The capacity of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) envelopes to transduce signals through chemokine coreceptors on macrophages was examined by measuring the ability of recombinant envelope proteins to mobilize intracellular calcium stores. Both HIV and SIV envelopes mobilized calcium via interactions with CCR5. The kinetics of these responses were similar to those observed when macrophages were treated with MIP-1β. Distinct differences in the capacity of envelopes to mediate calcium mobilization were observed. Envelopes derived from viruses capable of replicating in macrophages mobilized relatively high levels of calcium, while envelopes derived from viruses incapable of replicating in macrophages mobilized relatively low levels of calcium. The failure to efficiently mobilize calcium was not restricted to envelopes derived from CXCR4-utilizing isolates but also included envelopes derived from CCR5-utilizing isolates that fail to replicate in macrophages. We characterized one CCR5-utilizing isolate, 92MW959, which entered macrophages but failed to replicate. A recombinant envelope derived from this virus mobilized low levels of calcium. When macrophages were inoculated with 92MW959 in the presence of MIP-1α, viral replication was observed, indicating that a CC chemokine-mediated signal provided the necessary stimulus to allow the virus to complete its replication cycle. Although the role that envelope-CCR5 signal transduction plays in viral replication is not yet understood, it has been suggested that envelope-mediated signals facilitate early postfusion events in viral replication. The data presented here are consistent with this hypothesis and suggest that the differential capacity of viral envelopes to signal through CCR5 may influence their ability to replicate in macrophages. PMID:10864653
-
Arthos, J; Rubbert, A; Rabin, R L; Cicala, C; Machado, E; Wildt, K; Hanbach, M; Steenbeke, T D; Swofford, R; Farber, J M; Fauci, A S
2000-07-01
The capacity of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) envelopes to transduce signals through chemokine coreceptors on macrophages was examined by measuring the ability of recombinant envelope proteins to mobilize intracellular calcium stores. Both HIV and SIV envelopes mobilized calcium via interactions with CCR5. The kinetics of these responses were similar to those observed when macrophages were treated with MIP-1beta. Distinct differences in the capacity of envelopes to mediate calcium mobilization were observed. Envelopes derived from viruses capable of replicating in macrophages mobilized relatively high levels of calcium, while envelopes derived from viruses incapable of replicating in macrophages mobilized relatively low levels of calcium. The failure to efficiently mobilize calcium was not restricted to envelopes derived from CXCR4-utilizing isolates but also included envelopes derived from CCR5-utilizing isolates that fail to replicate in macrophages. We characterized one CCR5-utilizing isolate, 92MW959, which entered macrophages but failed to replicate. A recombinant envelope derived from this virus mobilized low levels of calcium. When macrophages were inoculated with 92MW959 in the presence of MIP-1alpha, viral replication was observed, indicating that a CC chemokine-mediated signal provided the necessary stimulus to allow the virus to complete its replication cycle. Although the role that envelope-CCR5 signal transduction plays in viral replication is not yet understood, it has been suggested that envelope-mediated signals facilitate early postfusion events in viral replication. The data presented here are consistent with this hypothesis and suggest that the differential capacity of viral envelopes to signal through CCR5 may influence their ability to replicate in macrophages.
-
Zhao, Ran; Sun, Junfeng; Qi, Tianming; Zhao, Wen; Han, Zongxi; Yang, Xiaopu; Liu, Shengwang
2017-04-25
The recombinant LaSota strain expressing a chimeric IBV S1 gene (rLaSota-S1) was constructed with the S1 gene of the LX4 type IBV ck/CH/LDL/091022. The expression of the S1 protein was detected by an indirect immunofluorescence assay and Western blotting. The rLaSota-S1 strain was slightly attenuated, and its growth dynamics were similar to that of the parental LaSota strain. Vaccination of specific pathogen-free chickens with the rLaSota-S1 strain induced NDV hemagglutination inhibition antibodies, and it protected chickens from challenge with virulent NDV. In addition, vaccination with the rLaSota-S1 strain induced IBV-specific IgG antibodies and cellular immunity; however, a single vaccination provided partial protection with reduced virus shedding. Better protection efficiency was observed after a booster vaccination, which resulted in higher antibody titers, significantly fewer disease symptoms, and reduced virus replication and shedding. Our results suggest that the rLaSota-S1 strain is a bivalent vaccine candidate against both NDV and IBV. Copyright © 2017 Elsevier Ltd. All rights reserved.
-
Wernet, Mathias F.; Klovstad, Martha; Clandinin, Thomas R.
2014-01-01
Arthropod RNA viruses pose a serious threat to human health, yet many aspects of their replication cycle remain incompletely understood. Here we describe a versatile Drosophila toolkit of transgenic, self-replicating genomes (‘replicons’) from Sindbis virus that allow rapid visualization and quantification of viral replication in vivo. We generated replicons expressing Luciferase for the quantification of viral replication, serving as useful new tools for large-scale genetic screens for identifying cellular pathways that influence viral replication. We also present a new binary system in which replication-deficient viral genomes can be activated ‘in trans’, through co-expression of an intact replicon contributing an RNA-dependent RNA polymerase. The utility of this toolkit for studying virus biology is demonstrated by the observation of stochastic exclusion between replicons expressing different fluorescent proteins, when co-expressed under control of the same cellular promoter. This process is analogous to ‘superinfection exclusion’ between virus particles in cell culture, a process that is incompletely understood. We show that viral polymerases strongly prefer to replicate the genome that encoded them, and that almost invariably only a single virus genome is stochastically chosen for replication in each cell. Our in vivo system now makes this process amenable to detailed genetic dissection. Thus, this toolkit allows the cell-type specific, quantitative study of viral replication in a genetic model organism, opening new avenues for molecular, genetic and pharmacological dissection of virus biology and tool development. PMID:25386852
-
Dutta, Debashis; Johnson, Samuel; Dalal, Alisha; Deymier, Martin J.; Hunter, Eric
2018-01-01
Traditional restriction endonuclease-based cloning has been routinely used to generate replication-competent simian-human immunodeficiency viruses (SHIV) and simian tropic HIV (stHIV). This approach requires the existence of suitable restriction sites or the introduction of nucleotide changes to create them. Here, using an In-Fusion cloning technique that involves homologous recombination, we generated SHIVs and stHIVs based on epidemiologically linked clade C transmitted/founder HIV molecular clones from Zambia. Replacing vif from these HIV molecular clones with vif of SIVmac239 resulted in chimeric genomes used to generate infectious stHIV viruses. Likewise, exchanging HIV env genes and introducing N375 mutations to enhance macaque CD4 binding site and cloned into a SHIVAD8-EO backbone. The generated SHIVs and stHIV were infectious in TZMbl and ZB5 cells, as well as macaque PBMCs. Therefore, this method can replace traditional methods and be a valuable tool for the rapid generation and testing of molecular clones of stHIV and SHIV based on primary clinical isolates will be valuable to generate rapid novel challenge viruses for HIV vaccine/cure studies. PMID:29758076
-
Blaney, Joseph E; Marzi, Andrea; Willet, Mallory; Papaneri, Amy B; Wirblich, Christoph; Feldmann, Friederike; Holbrook, Michael; Jahrling, Peter; Feldmann, Heinz; Schnell, Matthias J
2013-01-01
We have previously described the generation of a novel Ebola virus (EBOV) vaccine platform based on (a) replication-competent rabies virus (RABV), (b) replication-deficient RABV, or (c) chemically inactivated RABV expressing EBOV glycoprotein (GP). Mouse studies demonstrated safety, immunogenicity, and protective efficacy of these live or inactivated RABV/EBOV vaccines. Here, we evaluated these vaccines in nonhuman primates. Our results indicate that all three vaccines do induce potent immune responses against both RABV and EBOV, while the protection of immunized animals against EBOV was largely dependent on the quality of humoral immune response against EBOV GP. We also determined if the induced antibodies against EBOV GP differ in their target, affinity, or the isotype. Our results show that IgG1-biased humoral responses as well as high levels of GP-specific antibodies were beneficial for the control of EBOV infection after immunization. These results further support the concept that a successful EBOV vaccine needs to induce strong antibodies against EBOV. We also showed that a dual vaccine against RABV and filoviruses is achievable; therefore addressing concerns for the marketability of this urgently needed vaccine.
-
Methadone enhances human influenza A virus replication.
Chen, Yun-Hsiang; Wu, Kuang-Lun; Tsai, Ming-Ta; Chien, Wei-Hsien; Chen, Mao-Liang; Wang, Yun
2017-01-01
Growing evidence has indicated that opioids enhance replication of human immunodeficiency virus and hepatitis C virus in target cells. However, it is unknown whether opioids can enhance replication of other clinically important viral pathogens. In this study, the interaction of opioid agonists and human influenza A/WSN/33 (H1N1) virus was examined in human lung epithelial A549 cells. Cells were exposed to morphine, methadone or buprenorphine followed by human H1N1 viral infection. Exposure to methadone differentially enhanced viral propagation, consistent with an increase in virus adsorption, susceptibility to virus infection and viral protein synthesis. In contrast, morphine or buprenorphine did not alter H1N1 replication. Because A549 cells do not express opioid receptors, methadone-enhanced H1N1 replication in human lung cells may not be mediated through these receptors. The interaction of methadone and H1N1 virus was also examined in adult mice. Treatment with methadone significantly increased H1N1 viral replication in lungs. Our data suggest that use of methadone facilitates influenza A viral infection in lungs and might raise concerns regarding the possible consequence of an increased risk of serious influenza A virus infection in people who receive treatment in methadone maintenance programs. © 2015 Society for the Study of Addiction.
-
Yang, Liping; Wang, Rong; Yang, Shixing; Ma, Zexu; Lin, Shaoli; Nan, Yuchen; Li, Qisheng; Tang, Qiyi; Zhang, Yan-Jin
2018-05-01
Movement of macromolecules between the cytoplasm and the nucleus occurs through the nuclear pore complex (NPC). Karyopherins comprise a family of soluble transport factors facilitating the nucleocytoplasmic translocation of proteins through the NPC. In this study, we found that karyopherin α6 (KPNA6; also known as importin α7) was required for the optimal replication of porcine reproductive and respiratory syndrome virus (PRRSV) and Zika virus (ZIKV), which are positive-sense, single-stranded RNA viruses replicating in the cytoplasm. The KPNA6 protein level in virus-infected cells was much higher than that in mock-infected controls, whereas the KPNA6 transcript remains stable. Viral infection blocked the ubiquitin-proteasomal degradation of KPNA6, which led to an extension of the KPNA6 half-life and the elevation of the KPNA6 level in comparison to mock-infected cells. PRRSV nsp12 protein induced KPNA6 stabilization. KPNA6 silencing was detrimental to the replication of PRRSV, and KPNA6 knockout impaired ZIKV replication. Moreover, KPNA6 knockout blocked the nuclear translocation of PRRSV nsp1β but had a minimal effect on two other PRRSV proteins with nuclear localization. Exogenous restitution of KPNA6 expression in the KPNA6-knockout cells results in restoration of the nuclear translocation of PRRSV nsp1β and the replication of ZIKV. These results indicate that KPNA6 is an important cellular factor for the replication of PRRSV and ZIKV. IMPORTANCE Positive-sense, single-stranded RNA (+ssRNA) viruses replicate in the cytoplasm of infected cells. The roles of transport factors in the nucleocytoplasmic trafficking system for the replication of +ssRNA viruses are not known. In this study, we discovered that PRRSV and ZIKV viruses needed karyopherin α6 (KPNA6), one of the transport factors, to enhance the virus replication. Our data showed that viral infection induced an elevation of the KPNA6 protein level due to an extension of the KPNA6 half-life via viral interference of the ubiquitin-proteasomal degradation of KPNA6. Notably, KPNA6 silencing or knockout dramatically reduced the replication of PRRSV and ZIKV. PRRSV nsp1β depended on KPNA6 to translocate into the nucleus. In addition, exogenous restitution of KPNA6 expression in KPNA6-knockout cells led to the restoration of nsp1β nuclear translocation and ZIKV replication. These results reveal a new aspect in the virus-cell interaction and may facilitate the development of novel antiviral therapeutics. Copyright © 2018 American Society for Microbiology.
-
Ryan, Lisa K; Dai, Jihong; Yin, Zhiwei; Megjugorac, Nicholas; Uhlhorn, Victoria; Yim, Sunghan; Schwartz, Kyell D; Abrahams, Joshua M; Diamond, Gill; Fitzgerald-Bocarsly, Patricia
2011-08-01
hBD comprise a family of antimicrobial peptides that plays a role in bridging the innate and adaptive immune responses to infection. The expression of hBD-2 increases upon stimulation of numerous cell types with LPS and proinflammatory cytokines. In contrast, hBD-1 remains constitutively expressed in most cells in spite of cytokine or LPS stimulation; however, its presence in human PDC suggests it plays a role in viral host defense. To examine this, we characterized the expression of hBD-1 in innate immune cells in response to viral challenge. PDC and monocytes increased production of hBD-1 peptide and mRNA as early as 2 h following infection of purified cells and PBMCs with PR8, HSV-1, and Sendai virus. However, treatment of primary NHBE cells with influenza resulted in a 50% decrease in hBD-1 mRNA levels, as measured by qRT-PCR at 3 h following infection. A similar inhibition occurred with HSV-1 challenge of human gingival epithelial cells. Studies with HSV-1 showed that replication occurred in epithelial cells but not in PDC. Together, these results suggest that hBD-1 may play a role in preventing viral replication in immune cells. To test this, we infected C57BL/6 WT mice and mBD-1((-/-)) mice with mouse-adapted HK18 (300 PFU/mouse). mBD-1((-/-)) mice lost weight earlier and died sooner than WT mice (P=0.0276), suggesting that BD-1 plays a role in early innate immune responses against influenza in vivo. However, lung virus titers were equal between the two mouse strains. Histopathology showed a greater inflammatory influx in the lungs of mBD-1((-/-)) mice at Day 3 postinfection compared with WT C57BL/6 mice. The results suggest that BD-1 protects mice from influenza pathogenesis with a mechanism other than inhibition of viral replication.
-
USDA-ARS?s Scientific Manuscript database
Although most commonly associated with the infection of domestic livestock, the replication of pestiviruses, in particular bovine viral diarrhea virus (BVDV), occurs in a wide range of free ranging cervids including white-tailed deer, mule deer, fallow deer, elk, red deer, roe deer, eland and moused...
-
Kazlauskas, Darius; Krupovic, Mart; Venclovas, Česlovas
2016-06-02
Genomic DNA replication is a complex process that involves multiple proteins. Cellular DNA replication systems are broadly classified into only two types, bacterial and archaeo-eukaryotic. In contrast, double-stranded (ds) DNA viruses feature a much broader diversity of DNA replication machineries. Viruses differ greatly in both completeness and composition of their sets of DNA replication proteins. In this study, we explored whether there are common patterns underlying this extreme diversity. We identified and analyzed all major functional groups of DNA replication proteins in all available proteomes of dsDNA viruses. Our results show that some proteins are common to viruses infecting all domains of life and likely represent components of the ancestral core set. These include B-family polymerases, SF3 helicases, archaeo-eukaryotic primases, clamps and clamp loaders of the archaeo-eukaryotic type, RNase H and ATP-dependent DNA ligases. We also discovered a clear correlation between genome size and self-sufficiency of viral DNA replication, the unanticipated dominance of replicative helicases and pervasive functional associations among certain groups of DNA replication proteins. Altogether, our results provide a comprehensive view on the diversity and evolution of replication systems in the DNA virome and uncover fundamental principles underlying the orchestration of viral DNA replication. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.
-
2015-01-30
intracel- lular replication. Two classic replication modes have been described for single-stranded RNA viruses: the ‘stamping machine’ mode ( Stent ...Journal of Theoretical Biology 218:309–321. doi: 10.1006/jtbi.2002.3078. Stent GS. 1963. Molecular Biology of Bacterial Viruses. San Francisco, Calif: W H
-
NASA Astrophysics Data System (ADS)
Serio, D.; Rizvi, T. A.; Cartas, M.; Kalyanaraman, V. S.; Weber, I. T.; Koprowski, H.; Srinivasan, A.
1997-04-01
Effective antiviral agents will be of great value in controlling virus replication and delaying the onset of HIV-1-related disease symptoms. Current therapy involves the use of antiviral agents that target the enzymatic functions of the virus, resulting in the emergence of resistant viruses to these agents, thus lowering their effectiveness. To overcome this problem, we have considered the idea of developing novel agents from within HIV-1 as inhibitors of virus replication. The specificity of the Vpr protein for the HIV-1 virus particle makes it an attractive molecule for the development of antiviral agents targeting the events associated with virus maturation. We have generated chimeric Vpr proteins containing HIV-1-specific sequences added to the C terminus of Vpr. These sequences correspond to nine cleavage sites of the Gag and Gag-Pol precursors of HIV-1. The chimeric Vpr constructs were introduced into HIV-1 proviral DNA to assess their effect on virus infectivity using single- and multiple-round replication assays. The virus particles generated exhibited a variable replication pattern depending on the protease cleavage site used as a fusion partner. Interestingly, the chimeric Vpr containing the cleavage sequences from the junction of p24 and p2, 24/2, completely abolished virus infectivity. These results show that chimeric proteins generated from within HIV-1 have the ability to suppress HIV-1 replication and make ideal agents for gene therapy or intracellular immunization to treat HIV-1 infection.
-
Antiretroviral Agents Effectively Block HIV Replication after Cell-to-Cell Transfer
Permanyer, Marc; Ballana, Ester; Ruiz, Alba; Badia, Roger; Riveira-Munoz, Eva; Gonzalo, Encarna; Clotet, Bonaventura
2012-01-01
Cell-to-cell transmission of HIV has been proposed as a mechanism contributing to virus escape to the action of antiretrovirals and a mode of HIV persistence during antiretroviral therapy. Here, cocultures of infected HIV-1 cells with primary CD4+ T cells or lymphoid cells were used to evaluate virus transmission and the effect of known antiretrovirals. Transfer of HIV antigen from infected to uninfected cells was resistant to the reverse transcriptase inhibitors (RTIs) zidovudine (AZT) and tenofovir, but was blocked by the attachment inhibitor IgGb12. However, quantitative measurement of viral DNA production demonstrated that all anti-HIV agents blocked virus replication with similar potency to cell-free virus infections. Cell-free and cell-associated infections were equally sensitive to inhibition of viral replication when HIV-1 long terminal repeat (LTR)-driven green fluorescent protein (GFP) expression in target cells was measured. However, detection of GFP by flow cytometry may incorrectly estimate the efficacy of antiretrovirals in cell-associated virus transmission, due to replication-independent Tat-mediated LTR transactivation as a consequence of cell-to-cell events that did not occur in short-term (48-h) cell-free virus infections. In conclusion, common markers of virus replication may not accurately correlate and measure infectivity or drug efficacy in cell-to-cell virus transmission. When accurately quantified, active drugs blocked proviral DNA and virus replication in cell-to-cell transmission, recapitulating the efficacy of antiretrovirals in cell-free virus infections and in vivo. PMID:22696642
-
Ma, Hao; Song, Congfeng; Borth, Wayne; Sether, Diane; Melzer, Michael; Hu, John
2011-10-20
Tomato spotted wilt virus (TSWV) has a very wide host range, and is transmitted in a persistent manner by several species of thrips. These characteristics make this virus difficult to control. We show here that the over-expression of the mitochondrial alternative oxidase (AOX) in tomato and petunia is related to TSWV resistance. The open reading frame and full-length sequence of the tomato AOX gene LeAox1au were cloned and introduced into tomato 'Healani' and petunia 'Sheer Madness' using Agrobacterium-mediated transformation. Highly expressed AOX transgenic tomato and petunia plants were selfed and transgenic R1 seedlings from 10 tomato lines and 12 petunia lines were used for bioassay. For each assayed line, 22 to 32 tomato R1 progeny in three replications and 39 to 128 petunia progeny in 13 replications were challenged with TSWV. Enzyme-Linked Immunosorbent Assays showed that the TSWV levels in transgenic tomato line FKT4-1 was significantly lower than that of wild-type controls after challenge with TSWV. In addition, transgenic petunia line FKP10 showed significantly less lesion number and smaller lesion size than non-transgenic controls after inoculation by TSWV. In all assayed transgenic tomato lines, a higher percentage of transgenic progeny had lower TSWV levels than non-transgenic plants after challenge with TSWV, and the significantly increased resistant levels of tomato and petunia lines identified in this study indicate that altered expression levels of AOX in tomato and petunia can affect the levels of TSWV resistance.
-
2011-01-01
Background Tomato spotted wilt virus (TSWV) has a very wide host range, and is transmitted in a persistent manner by several species of thrips. These characteristics make this virus difficult to control. We show here that the over-expression of the mitochondrial alternative oxidase (AOX) in tomato and petunia is related to TSWV resistance. Results The open reading frame and full-length sequence of the tomato AOX gene LeAox1au were cloned and introduced into tomato 'Healani' and petunia 'Sheer Madness' using Agrobacterium-mediated transformation. Highly expressed AOX transgenic tomato and petunia plants were selfed and transgenic R1 seedlings from 10 tomato lines and 12 petunia lines were used for bioassay. For each assayed line, 22 to 32 tomato R1 progeny in three replications and 39 to 128 petunia progeny in 13 replications were challenged with TSWV. Enzyme-Linked Immunosorbent Assays showed that the TSWV levels in transgenic tomato line FKT4-1 was significantly lower than that of wild-type controls after challenge with TSWV. In addition, transgenic petunia line FKP10 showed significantly less lesion number and smaller lesion size than non-transgenic controls after inoculation by TSWV. Conclusion In all assayed transgenic tomato lines, a higher percentage of transgenic progeny had lower TSWV levels than non-transgenic plants after challenge with TSWV, and the significantly increased resistant levels of tomato and petunia lines identified in this study indicate that altered expression levels of AOX in tomato and petunia can affect the levels of TSWV resistance. PMID:22014312
-
Gonzalez, J P; Cornet, J P; Wilson, M L; Camicas, J L
1991-01-01
The kinetics of the replication of the Crimean-Congo haemorrhagic fever virus (CCHFV) was studied in intra-anally inoculated adult Hyalomma truncatum and Amblyomma variegatum ticks. The virus was re-isolated by suckling mouse inoculation and revealed by antigen capture with ground ticks and indirect immunofluorescence of haemolymph. The virus was detected in ticks in the first hours post-inoculation (p.i.) and its replication was observed from 36 h p.i. onwards. Virus titre reached a maximum within 3-5 days then decreased slowly to a level of at 2 log LD50/ml for several months until the end of observations. Several specific, non-identified factors seem to favour CCHFV replication in H. truncatum. Long-term virus persistence seems to occur in CCHFV-infected adult ticks.
-
Investigation of the role of GBF1 in the replication of positive-sense single-stranded RNA viruses.
Ferlin, Juliette; Farhat, Rayan; Belouzard, Sandrine; Cocquerel, Laurence; Bertin, Antoine; Hober, Didier; Dubuisson, Jean; Rouillé, Yves
2018-06-20
GBF1 has emerged as a host factor required for the replication of positive-sense single-stranded RNA viruses of different families, but its mechanism of action is still unknown. GBF1 is a guanine nucleotide exchange factor for Arf family members. Recently, we identified Arf4 and Arf5 (class II Arfs) as host factors required for the replication of hepatitis C virus (HCV), a GBF1-dependent virus. To assess whether a GBF1/class II Arf pathway is conserved among positive-sense single-stranded RNA viruses, we investigated yellow fever virus (YFV), Sindbis virus (SINV), coxsackievirus B4 (CVB4) and human coronavirus 229E (HCoV-229E). We found that GBF1 is involved in the replication of these viruses. However, using siRNA or CRISPR-Cas9 technologies, it was seen that the depletion of Arf1, Arf3, Arf4 or Arf5 had no impact on viral replication. In contrast, the depletion of Arf pairs suggested that class II Arfs could be involved in HCoV-229E, YFV and SINV infection, as for HCV, but not in CVB4 infection. In addition, another Arf pair, Arf1 and Arf4, appears to be essential for YFV and SINV infection, but not for infection by other viruses. Finally, CVB4 infection was not inhibited by any combination of Arf depletion. We conclude that the mechanism of action of GBF1 in viral replication appears not to be conserved, and that a subset of positive-sense single-stranded RNA viruses from different families might require class II Arfs for their replication.
-
Adeyemi, Richard O.
2012-01-01
The DNA damage response to infection with minute virus of mice (MVM) leads to activated p53; however, p21 levels are reduced via a proteasome-mediated mechanism. This loss was sustained, as virus replicated in infected cells held at the G2/M border. Addition of the cyclin-dependent kinase (CDK) inhibitor roscovitine after S-phase entry reduced MVM replication, suggesting that CDK activity was critical for continued viral replication and virus-induced reduction of p21 may thus be necessary to prevent inhibition of CDK. PMID:22623787
-
Esser-Nobis, Katharina; Harak, Christian; Schult, Philipp; Kusov, Yuri; Lohmann, Volker
2015-08-01
Hepatitis A virus (HAV) and hepatitis C virus (HCV) are two positive-strand RNA viruses sharing a similar biology, but causing opposing infection outcomes, with HAV always being cleared and HCV establishing persistence in the majority of infections. To gain deeper insight into determinants of replication, persistence, and treatment, we established a homogenous cell-culture model allowing a thorough comparison of RNA replication of both viruses. By screening different human liver-derived cell lines with subgenomic reporter replicons of HAV as well as of different HCV genotypes, we found that Huh7-Lunet cells supported HAV- and HCV-RNA replication with similar efficiency and limited interference between both replicases. HAV and HCV replicons were similarly sensitive to interferon (IFN), but differed in their ability to establish persistent replication in cell culture. In contrast to HCV, HAV replicated independently from microRNA-122 and phosphatidylinositol 4-kinase IIIα and β (PI4KIII). Both viruses were efficiently inhibited by cyclosporin A and NIM811, a nonimmunosuppressive analog thereof, suggesting an overlapping dependency on cyclophilins for replication. However, analysis of a broader set of inhibitors revealed that, in contrast to HCV, HAV does not depend on cyclophilin A, but rather on adenosine-triphosphate-binding cassette transporters and FK506-binding proteins. Finally, silibinin, but not its modified intravenous formulation, efficiently inhibited HAV genome replication in vitro, suggesting oral silibinin as a potential therapeutic option for HAV infections. We established a cell-culture model enabling comparative studies on RNA replication of HAV and HCV in a homogenous cellular background with comparable replication efficiency. We thereby identified new host cell targets and potential treatment options for HAV and set the ground for future studies to unravel determinants of clearance and persistence. © 2015 by the American Association for the Study of Liver Diseases.
-
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.
-
Kallert, Sandra M.; Darbre, Stephanie; Bonilla, Weldy V.; Kreutzfeldt, Mario; Page, Nicolas; Müller, Philipp; Kreuzaler, Matthias; Lu, Min; Favre, Stéphanie; Kreppel, Florian; Löhning, Max; Luther, Sanjiv A.; Zippelius, Alfred; Merkler, Doron; Pinschewer, Daniel D.
2017-01-01
Viral infections lead to alarmin release and elicit potent cytotoxic effector T lymphocyte (CTLeff) responses. Conversely, the induction of protective tumour-specific CTLeff and their recruitment into the tumour remain challenging tasks. Here we show that lymphocytic choriomeningitis virus (LCMV) can be engineered to serve as a replication competent, stably-attenuated immunotherapy vector (artLCMV). artLCMV delivers tumour-associated antigens to dendritic cells for efficient CTL priming. Unlike replication-deficient vectors, artLCMV targets also lymphoid tissue stroma cells expressing the alarmin interleukin-33. By triggering interleukin-33 signals, artLCMV elicits CTLeff responses of higher magnitude and functionality than those induced by replication-deficient vectors. Superior anti-tumour efficacy of artLCMV immunotherapy depends on interleukin-33 signalling, and a massive CTLeff influx triggers an inflammatory conversion of the tumour microenvironment. Our observations suggest that replicating viral delivery systems can release alarmins for improved anti-tumour efficacy. These mechanistic insights may outweigh safety concerns around replicating viral vectors in cancer immunotherapy. PMID:28548102
-
A novel subviral agent associated with a geminivirus: The first report of a DNA satellite
Dry, Ian B.; Krake, Leslie R.; Rigden, Justin E.; Rezaian, M. Ali
1997-01-01
Numerous plant RNA viruses have associated with them satellite (sat) RNAs that have little or no nucleotide sequence similarity to either the viral or host genomes but are completely dependent on the helper virus for replication. We report here on the discovery of a 682-nt circular DNA satellite associated with tomato leaf curl geminivirus (TLCV) infection in northern Australia. This is the first demonstration that satellite molecules are not limited to RNA viral systems. The DNA satellite (TLCV sat-DNA) is strictly dependent for replication on the helper virus replication-associated protein and is encapsidated by TLCV coat protein. It has no significant open reading frames, and it shows no significant sequence similarity to the 2766-nt helper-virus genome except for two short motifs present in separate putative stem–loop structures: TAATATTAC, which is universally conserved in all geminiviruses, and AATCGGTGTC, which is identical to a putative replication-associated protein binding motif in TLCV. Replication of TLCV sat-DNA is also supported by other taxonomically distinct geminiviruses, including tomato yellow leaf curl virus, African cassava mosaic virus, and beet curly top virus. Therefore, this unique DNA satellite does not appear to strictly conform with the requirements that dictate the specificity of interaction of geminiviral replication-associated proteins with their cognate origins as predicted by the current model of geminivirus replication. PMID:9192696
-
Mimivirus: leading the way in the discovery of giant viruses of amoebae.
Colson, Philippe; La Scola, Bernard; Levasseur, Anthony; Caetano-Anollés, Gustavo; Raoult, Didier
2017-04-01
The accidental discovery of the giant virus of amoeba - Acanthamoeba polyphaga mimivirus (APMV; more commonly known as mimivirus) - in 2003 changed the field of virology. Viruses were previously defined by their submicroscopic size, which probably prevented the search for giant viruses, which are visible by light microscopy. Extended studies of giant viruses of amoebae revealed that they have genetic, proteomic and structural complexities that were not thought to exist among viruses and that are comparable to those of bacteria, archaea and small eukaryotes. The giant virus particles contain mRNA and more than 100 proteins, they have gene repertoires that are broader than those of other viruses and, notably, some encode translation components. The infection cycles of giant viruses of amoebae involve virus entry by amoebal phagocytosis and replication in viral factories. In addition, mimiviruses are infected by virophages, defend against them through the mimivirus virophage resistance element (MIMIVIRE) system and have a unique mobilome. Overall, giant viruses of amoebae, including mimiviruses, marseilleviruses, pandoraviruses, pithoviruses, faustoviruses and molliviruses, challenge the definition and classification of viruses, and have increasingly been detected in humans.
-
Beck, Juergen; Nassal, Michael
2007-01-01
Hepadnaviruses, including human hepatitis B virus (HBV), replicate through reverse transcription of an RNA intermediate, the pregenomic RNA (pgRNA). Despite this kinship to retroviruses, there are fundamental differences beyond the fact that hepadnavirions contain DNA instead of RNA. Most peculiar is the initiation of reverse transcription: it occurs by protein-priming, is strictly committed to using an RNA hairpin on the pgRNA, ε, as template, and depends on cellular chaperones; moreover, proper replication can apparently occur only in the specialized environment of intact nucleocapsids. This complexity has hampered an in-depth mechanistic understanding. The recent successful reconstitution in the test tube of active replication initiation complexes from purified components, for duck HBV (DHBV), now allows for the analysis of the biochemistry of hepadnaviral replication at the molecular level. Here we review the current state of knowledge at all steps of the hepadnaviral genome replication cycle, with emphasis on new insights that turned up by the use of such cell-free systems. At this time, they can, unfortunately, not be complemented by three-dimensional structural information on the involved components. However, at least for the ε RNA element such information is emerging, raising expectations that combining biophysics with biochemistry and genetics will soon provide a powerful integrated approach for solving the many outstanding questions. The ultimate, though most challenging goal, will be to visualize the hepadnaviral reverse transcriptase in the act of synthesizing DNA, which will also have strong implications for drug development. PMID:17206754
-
Targeted genetic and viral therapy for advanced head and neck cancers.
Huang, Pin-I; Chang, Ju-Fang; Kirn, David H; Liu, Ta-Chiang
2009-06-01
Head and neck cancers usually present with advanced disease and novel therapies are urgently needed. Genetic therapy aims at restoring malfunctioned tumor suppressor gene(s) or introducing proapoptotic genes. Oncolytic virotherapeutics induce multiple cycles of cancer-specific virus replication, followed by oncolysis, virus spreading and infection of adjacent cancer cells. Oncolytic viruses can also be armed to express therapeutic transgene(s). Recent advances in preclinical and clinical studies are revealing the potential of both therapeutic classes for advanced head and neck cancers, including the approval of two products (Gendicine and H101) by a governmental agency. This review summarizes the available clinical data to date and discusses the challenges and future directions.
-
Protein Interactions during the Flavivirus and Hepacivirus Life Cycle.
Gerold, Gisa; Bruening, Janina; Weigel, Bettina; Pietschmann, Thomas
2017-04-01
Protein-protein interactions govern biological functions in cells, in the extracellular milieu, and at the border between cells and extracellular space. Viruses are small intracellular parasites and thus rely on protein interactions to produce progeny inside host cells and to spread from cell to cell. Usage of host proteins by viruses can have severe consequences e.g. apoptosis, metabolic disequilibria, or altered cell proliferation and mobility. Understanding protein interactions during virus infection can thus educate us on viral infection and pathogenesis mechanisms. Moreover, it has led to important clinical translations, including the development of new therapeutic and vaccination strategies. Here, we will discuss protein interactions of members of the Flaviviridae family, which are small enveloped RNA viruses. Dengue virus, Zika virus and hepatitis C virus belong to the most prominent human pathogenic Flaviviridae With a genome of roughly ten kilobases encoding only ten viral proteins, Flaviviridae display intricate mechanisms to engage the host cell machinery for their purpose. In this review, we will highlight how dengue virus, hepatitis C virus, Japanese encephalitis virus, tick-borne encephalitis virus, West Nile virus, yellow fever virus, and Zika virus proteins engage host proteins and how this knowledge helps elucidate Flaviviridae infection. We will specifically address the protein composition of the virus particle as well as the protein interactions during virus entry, replication, particle assembly, and release from the host cell. Finally, we will give a perspective on future challenges in Flaviviridae interaction proteomics and why we believe these challenges should be met. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.
-
Dittrich, Anne; Scheibner, David; Salaheldin, Ahmed H; Veits, Jutta; Gischke, Marcel; Mettenleiter, Thomas C; Abdelwhab, Elsayed M
2018-02-14
Wild birds are the reservoir for low-pathogenic avian influenza viruses, which are frequently transmitted to domestic birds and occasionally to mammals. In 2014, an H10N7 virus caused severe mortality in harbor seals in northeastern Europe. Although the hemagglutinin (HA) of this virus was closely related to H10 of avian H10N4 virus, it possessed unique nonsynonymous mutations, particularly in the HA1 subunit in or adjacent to the receptor binding domain and proteolytic cleavage site. Here, the impact of these mutations on virus replication was studied in vitro. Using reverse genetics, an avian H10N4 virus was cloned, and nine recombinant viruses carrying one of eight unique mutations or the complete HA from the seal virus were rescued. Receptor binding affinity, replication in avian and mammalian cell cultures, cell-to-cell spread, and HA cleavability of these recombinant viruses were studied. Results show that wild-type recombinant H10N4 virus has high affinity to avian-type sialic acid receptors and no affinity to mammalian-type receptors. The H10N7 virus exhibits dual receptor binding affinity. Interestingly, Q220L (H10 numbering) in the rim of the receptor binding pocket increased the affinity of the H10N4 virus to mammal-type receptors and completely abolished the affinity to avian-type receptors. No remarkable differences in cell-to-cell spread or HA cleavability were observed. All viruses, including the wild-type H10N7 virus, replicated at higher levels in chicken cells than in human cells. These results indicate that H10N7 acquired adaptive mutations (e.g., Q220L) to enhance replication in mammals and retained replication efficiency in the original avian host.
-
Dittrich, Anne; Scheibner, David; Salaheldin, Ahmed H.; Veits, Jutta; Gischke, Marcel
2018-01-01
Wild birds are the reservoir for low-pathogenic avian influenza viruses, which are frequently transmitted to domestic birds and occasionally to mammals. In 2014, an H10N7 virus caused severe mortality in harbor seals in northeastern Europe. Although the hemagglutinin (HA) of this virus was closely related to H10 of avian H10N4 virus, it possessed unique nonsynonymous mutations, particularly in the HA1 subunit in or adjacent to the receptor binding domain and proteolytic cleavage site. Here, the impact of these mutations on virus replication was studied in vitro. Using reverse genetics, an avian H10N4 virus was cloned, and nine recombinant viruses carrying one of eight unique mutations or the complete HA from the seal virus were rescued. Receptor binding affinity, replication in avian and mammalian cell cultures, cell-to-cell spread, and HA cleavability of these recombinant viruses were studied. Results show that wild-type recombinant H10N4 virus has high affinity to avian-type sialic acid receptors and no affinity to mammalian-type receptors. The H10N7 virus exhibits dual receptor binding affinity. Interestingly, Q220L (H10 numbering) in the rim of the receptor binding pocket increased the affinity of the H10N4 virus to mammal-type receptors and completely abolished the affinity to avian-type receptors. No remarkable differences in cell-to-cell spread or HA cleavability were observed. All viruses, including the wild-type H10N7 virus, replicated at higher levels in chicken cells than in human cells. These results indicate that H10N7 acquired adaptive mutations (e.g., Q220L) to enhance replication in mammals and retained replication efficiency in the original avian host. PMID:29443887
-
Deeg, Christoph M; Chow, Cheryl-Emiliane T
2018-01-01
Giant viruses are ecologically important players in aquatic ecosystems that have challenged concepts of what constitutes a virus. Herein, we present the giant Bodo saltans virus (BsV), the first characterized representative of the most abundant group of giant viruses in ocean metagenomes, and the first isolate of a klosneuvirus, a subgroup of the Mimiviridae proposed from metagenomic data. BsV infects an ecologically important microzooplankton, the kinetoplastid Bodo saltans. Its 1.39 Mb genome encodes 1227 predicted ORFs, including a complex replication machinery. Yet, much of its translational apparatus has been lost, including all tRNAs. Essential genes are invaded by homing endonuclease-encoding self-splicing introns that may defend against competing viruses. Putative anti-host factors show extensive gene duplication via a genomic accordion indicating an ongoing evolutionary arms race and highlighting the rapid evolution and genomic plasticity that has led to genome gigantism and the enigma that is giant viruses. PMID:29582753
-
Nigericin is a potent inhibitor of the early stage of vaccinia virus replication.
Myskiw, Chad; Piper, Jessica; Huzarewich, Rhiannon; Booth, Tim F; Cao, Jingxin; He, Runtao
2010-12-01
Poxviruses remain a significant public health concern due to their potential use as bioterrorist agents and the spread of animal borne poxviruses, such as monkeypox virus, to humans. Thus, the identification of small molecule inhibitors of poxvirus replication is warranted. Vaccinia virus is the prototypic member of the Orthopoxvirus genus, which also includes variola and monkeypox virus. In this study, we demonstrate that the carboxylic ionophore nigericin is a potent inhibitor of vaccinia virus replication in several human cell lines. In HeLa cells, we found that the 50% inhibitory concentration of nigericin against vaccinia virus was 7.9 nM, with a selectivity index of 1038. We present data demonstrating that nigericin targets vaccinia virus replication at a post-entry stage. While nigericin moderately inhibits both early vaccinia gene transcription and translation, viral DNA replication and intermediate and late gene expression are severely compromised in the presence of nigericin. Our results demonstrate that nigericin has the potential to be further developed into an effective antiviral to treat poxvirus infections. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.
-
Lee, Jinhwa; Yu, Hai; Li, Yonghai; Ma, Jingjiao; Lang, Yuekun; Duff, Michael; Henningson, Jamie; Liu, Qinfang; Li, Yuhao; Nagy, Abdou; Bawa, Bhupinder; Li, Zejun; Tong, Guangzhi; Richt, Juergen A.; Ma, Wenjun
2017-01-01
Although several studies have investigated the functions of influenza PA-X, the impact of different expressions of PA-X protein including full-length, truncated or PA-X deficient forms on virus replication, pathogenicity and host response remains unclear. Herein, we generated two mutated viruses expressing a full-length or deficient PA-X protein based on the A/California/04/2009 (H1N1) virus that expresses a truncated PA-X to understand three different expressions of PA-X protein on virus replication, pathogenicity and host immune responses. The results showed that expression of either full-length or truncated PA-X protein enhanced viral replication and pathogenicity as well as reduced host innate immune response in mice by host shutoff activity when compared to the virus expressing the deficient PA-X form. Furthermore, the full-length PA-X expression exhibited a greater effect on virus pathogenicity than the truncated PA-X form. Our results provide novel insights of PA-X on viral replication, pathogenicity and host immune responses. PMID:28142079
-
Chan, Renee W Y; Chan, Louisa L Y; Mok, Chris K P; Lai, Jimmy; Tao, Kin P; Obadan, Adebimpe; Chan, Michael C W; Perez, Daniel R; Peiris, J S Malik; Nicholls, John M
2017-07-24
H9N2 viruses are the most widespread influenza viruses in poultry in Asia. We evaluated the infection and tropism of human and avian H9 influenza virus in the human respiratory tract using ex vivo respiratory organ culture. H9 viruses infected the upper and lower respiratory tract and the majority of H9 viruses had a decreased ability to release virus from the bronchus rather than the lung. This may be attributed to a weak neuraminidase (NA) cleavage of carbon-6-linked sialic acid (Sia) rather than carbon-3-linked Sia. The modified cleavage of N-acetlylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc) by NA in H9 virus replication was observed by reverse genetics, and recombinant H9N2 viruses with amino acids (38KQ) deleted in the NA stalk, and changing the amino acid at position 431 from Proline-to-Lysine. Using recombinant H9 viruses previously evaluated in the ferret, we found that viruses which replicated well in the ferret did not replicate to the same extent in the human ex vivo cultures. The existing risk assessment models for H9N2 viruses in ferrets may not always have a strong correlation with the replication in the human upper respiratory tract. The inclusion of the human ex vivo cultures would further strengthen the future risk-assessment strategies.
-
Vaccines. An Ebola whole-virus vaccine is protective in nonhuman primates.
Marzi, Andrea; Halfmann, Peter; Hill-Batorski, Lindsay; Feldmann, Friederike; Shupert, W Lesley; Neumann, Gabriele; Feldmann, Heinz; Kawaoka, Yoshihiro
2015-04-24
Zaire ebolavirus is the causative agent of the current outbreak of hemorrhagic fever disease in West Africa. Previously, we showed that a whole Ebola virus (EBOV) vaccine based on a replication-defective EBOV (EBOVΔVP30) protects immunized mice and guinea pigs against lethal challenge with rodent-adapted EBOV. Here, we demonstrate that EBOVΔVP30 protects nonhuman primates against lethal infection with EBOV. Although EBOVΔVP30 is replication-incompetent, we additionally inactivated the vaccine with hydrogen peroxide; the chemically inactivated vaccine remained antigenic and protective in nonhuman primates. EBOVΔVP30 thus represents a safe, efficacious, whole-EBOV vaccine candidate that differs from other EBOV vaccine platforms in that it presents all viral proteins and the viral RNA to the host immune system, which might contribute to protective immune responses. Copyright © 2015, American Association for the Advancement of Science.
-
The replication of Bangladeshi H9N2 avian influenza viruses carrying genes from H7N3 in mammals
Shanmuganatham, Karthik K; Jones, Jeremy C; Marathe, Bindumadhav M; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Turner, Jasmine; Rabiul Alam, S M; Kamrul Hasan, M; Akhtar, Sharmin; Seiler, Patrick; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G
2016-01-01
H9N2 avian influenza viruses are continuously monitored by the World Health Organization because they are endemic; they continually reassort with H5N1, H7N9 and H10N8 viruses; and they periodically cause human infections. We characterized H9N2 influenza viruses carrying internal genes from highly pathogenic H7N3 viruses, which were isolated from chickens or quail from live-bird markets in Bangladesh between 2010 and 2013. All of the H9N2 viruses used in this study carried mammalian host-specific mutations. We studied their replication kinetics in normal human bronchoepithelial cells and swine tracheal and lung explants, which exhibit many features of the mammalian airway epithelium and serve as a mammalian host model. All H9N2 viruses replicated to moderate-to-high titers in the normal human bronchoepithelial cells and swine lung explants, but replication was limited in the swine tracheal explants. In Balb/c mice, the H9N2 viruses were nonlethal, replicated to moderately high titers and the infection was confined to the lungs. In the ferret model of human influenza infection and transmission, H9N2 viruses possessing the Q226L substitution in hemagglutinin replicated well without clinical signs and spread via direct contact but not by aerosol. None of the H9N2 viruses tested were resistant to the neuraminidase inhibitors. Our study shows that the Bangladeshi H9N2 viruses have the potential to infect humans and highlights the importance of monitoring and characterizing this influenza subtype to better understand the potential risk these viruses pose to humans. PMID:27094903
-
The replication of Bangladeshi H9N2 avian influenza viruses carrying genes from H7N3 in mammals.
Shanmuganatham, Karthik K; Jones, Jeremy C; Marathe, Bindumadhav M; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Turner, Jasmine; Rabiul Alam, S M; Kamrul Hasan, M; Akhtar, Sharmin; Seiler, Patrick; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G
2016-04-20
H9N2 avian influenza viruses are continuously monitored by the World Health Organization because they are endemic; they continually reassort with H5N1, H7N9 and H10N8 viruses; and they periodically cause human infections. We characterized H9N2 influenza viruses carrying internal genes from highly pathogenic H7N3 viruses, which were isolated from chickens or quail from live-bird markets in Bangladesh between 2010 and 2013. All of the H9N2 viruses used in this study carried mammalian host-specific mutations. We studied their replication kinetics in normal human bronchoepithelial cells and swine tracheal and lung explants, which exhibit many features of the mammalian airway epithelium and serve as a mammalian host model. All H9N2 viruses replicated to moderate-to-high titers in the normal human bronchoepithelial cells and swine lung explants, but replication was limited in the swine tracheal explants. In Balb/c mice, the H9N2 viruses were nonlethal, replicated to moderately high titers and the infection was confined to the lungs. In the ferret model of human influenza infection and transmission, H9N2 viruses possessing the Q226L substitution in hemagglutinin replicated well without clinical signs and spread via direct contact but not by aerosol. None of the H9N2 viruses tested were resistant to the neuraminidase inhibitors. Our study shows that the Bangladeshi H9N2 viruses have the potential to infect humans and highlights the importance of monitoring and characterizing this influenza subtype to better understand the potential risk these viruses pose to humans.
-
Zamora, Paula F; Hu, Liya; Knowlton, Jonathan J; Lahr, Roni M; Moreno, Rodolfo A; Berman, Andrea J; Prasad, B V Venkataram; Dermody, Terence S
2018-05-16
Viral nonstructural proteins, which are not packaged into virions, are essential for replication of most viruses. Reovirus, a nonenveloped, double-stranded RNA (dsRNA) virus, encodes three nonstructural proteins that are required for viral replication and dissemination in the host. Reovirus nonstructural protein σNS is a single-stranded RNA (ssRNA)-binding protein that must be expressed in infected cells for production of viral progeny. However, activities of σNS during individual steps of the reovirus replication cycle are poorly understood. We explored the function of σNS by disrupting its expression during infection using cells expressing a small interfering RNA (siRNA) targeting the σNS-encoding S3 gene and found that σNS is required for viral genome replication. Using complementary biochemical assays, we determined that σNS forms complexes with viral and nonviral RNAs. We also discovered that σNS increases RNA half-life using in vitro and cell-based RNA degradation experiments. Cryo-electron microscopy revealed that σNS and ssRNAs organize into long, filamentous structures. Collectively, our findings indicate that σNS functions as an RNA-binding protein that increases viral RNA half-life. These results suggest that σNS forms RNA-protein complexes in preparation for genome replication. IMPORTANCE Following infection, viruses synthesize nonstructural proteins that mediate viral replication and promote dissemination. Viruses from the Reoviridae family encode nonstructural proteins that are required for the formation of progeny viruses. Although nonstructural proteins of different Reoviridae family viruses are diverged in primary sequence, these proteins are functionally homologous and appear to facilitate conserved mechanisms of dsRNA virus replication. Using in vitro and cell-culture approaches, we found that the mammalian reovirus nonstructural protein σNS binds and stabilizes viral RNA and is required for genome synthesis. This work contributes new knowledge about basic mechanisms of dsRNA virus replication and provides a foundation for future studies to determine how viruses in the Reoviridae family assort and replicate their genomes. Copyright © 2018 American Society for Microbiology.
-
Foy, Niall J.; Akhrymuk, Maryna; Shustov, Alexander V.; Frolova, Elena I.
2013-01-01
Venezuelan equine encephalitis virus (VEEV) is one of the most pathogenic members of the Alphavirus genus in the Togaviridae family. This genus is divided into the Old World and New World alphaviruses, which demonstrate profound differences in pathogenesis, replication, and virus-host interactions. VEEV is a representative member of the New World alphaviruses. The biology of this virus is still insufficiently understood, particularly the function of its nonstructural proteins in RNA replication and modification of the intracellular environment. One of these nonstructural proteins, nsP3, contains a hypervariable domain (HVD), which demonstrates very low overall similarity between different alphaviruses, suggesting the possibility of its function in virus adaptation to different hosts and vectors. The results of our study demonstrate the following. (i) Phosphorylation of the VEEV nsP3-specific HVD does not play a critical role in virus replication in cells of vertebrate origin but is important for virus replication in mosquito cells. (ii) The VEEV HVD is not required for viral RNA replication in the highly permissive BHK-21 cell line. In fact, it can be either completely deleted or replaced by a heterologous protein sequence. These variants require only one or two additional adaptive mutations in nsP3 and/or nsP2 proteins to achieve an efficiently replicating phenotype. (iii) However, the carboxy-terminal repeat in the VEEV HVD is indispensable for VEEV replication in the cell lines other than BHK-21 and plays a critical role in formation of VEEV-specific cytoplasmic protein complexes. Natural VEEV variants retain at least one of the repeated elements in their nsP3 HVDs. PMID:23637407
-
Pathogenicity and Transmission of H5 and H7 Highly Pathogenic Avian Influenza Viruses in Mallards
Costa-Hurtado, Mar; Shepherd, Eric; DeJesus, Eric; Smith, Diane; Spackman, Erica; Kapczynski, Darrell R.; Suarez, David L.; Stallknecht, David E.; Swayne, David E.
2016-01-01
ABSTRACT Wild aquatic birds have been associated with the intercontinental spread of H5 subtype highly pathogenic avian influenza (HPAI) viruses of the A/goose/Guangdong/1/96 (Gs/GD) lineage during 2005, 2010, and 2014, but dispersion by wild waterfowl has not been implicated with spread of other HPAI viruses. To better understand why Gs/GD H5 HPAI viruses infect and transmit more efficiently in waterfowl than other HPAI viruses, groups of mallard ducks were challenged with one of 14 different H5 and H7 HPAI viruses, including a Gs/GD lineage H5N1 (clade 2.2) virus from Mongolia, part of the 2005 dispersion, and the H5N8 and H5N2 index HPAI viruses (clade 2.3.4.4) from the United States, part of the 2014 dispersion. All virus-inoculated ducks and contact exposed ducks became infected and shed moderate to high titers of the viruses, with the exception that mallards were resistant to Ck/Pennsylvania/83 and Ck/Queretaro/95 H5N2 HPAI virus infection. Clinical signs were only observed in ducks challenged with the H5N1 2005 virus, which all died, and with the H5N8 and H5N2 2014 viruses, which had decreased weight gain and fever. These three viruses were also shed in higher titers by the ducks, which could facilitate virus transmission and spread. This study highlights the possible role of wild waterfowl in the spread of HPAI viruses. IMPORTANCE The spread of H5 subtype highly pathogenic avian influenza (HPAI) viruses of the Gs/GD lineage by migratory waterfowl is a serious concern for animal and public health. H5 and H7 HPAI viruses are considered to be adapted to gallinaceous species (chickens, turkeys, quail, etc.) and less likely to infect and transmit in wild ducks. In order to understand why this is different with certain Gs/GD lineage H5 HPAI viruses, we compared the pathogenicity and transmission of several H5 and H7 HPAI viruses from previous poultry outbreaks to Gs/GD lineage H5 viruses, including H5N1 (clade 2.2), H5N8 and H5N2 (clade 2.3.4.4) viruses, in mallards as a representative wild duck species. Surprisingly, most HPAI viruses examined in this study replicated well and transmitted among mallards; however, the three Gs/GD lineage H5 HPAI viruses replicated to higher titers, which could explain the transmission of these viruses in susceptible wild duck populations. PMID:27558429
-
Ma, Ji-Hong; Yang, Fu-Ru; Yu, Hai; Zhou, Yan-Jun; Li, Guo-Xin; Huang, Meng; Wen, Feng; Tong, Guangzhi
2013-07-09
Vaccination is considered as the most effective preventive method to control influenza. The hallmark of influenza virus is the remarkable variability of its major surface glycoproteins, HA and NA, which allows the virus to evade existing anti-influenza immunity in the target population. So it is necessary to develop a novel vaccine to control animal influenza virus. Also we know that the ectodomain of influenza matrix protein 2 (M2e) is highly conserved in animal influenza A viruses, so a vaccine based on the M2e could avoid several drawbacks of the traditional vaccines. In this study we designed a novel tetra-branched multiple antigenic peptide (MAP) based vaccine, which was constructed by fusing four copies of M2e to one copy of foreign T helper (Th) cell epitope, and then investigated its immune responses. Our results show that the M2e-MAP induced strong M2e-specific IgG antibody,which responses following 2 doses immunization in the presence of Freunds' adjuvant. M2e-MAP vaccination limited viral replication substantially. Also it could attenuate histopathological damage in the lungs of challenged mice and counteracted weight loss. M2e-MAP-based vaccine protected immunized mice against the lethal challenge with PR8 virus. Based on these findings, M2e-MAP-based vaccine seemed to provide useful information for the research of M2e-based influenza vaccine. Also it show huge potential to study vaccines for other similarly viruses.
-
Evaluation of porcine reproductive and respiratory syndrome virus replication in laboratory rodents
Rosenfeld, Paul; Turner, Patricia V.; MacInnes, Janet I.; Nagy, Éva; Yoo, Dongwan
2009-01-01
Porcine reproductive and respiratory syndrome virus (PRRSV) is a major cause of economic losses in the swine industry. The disease is widespread worldwide, and so PRRSV-negative pigs are often difficult to find for the study of PRRSV in vivo. To determine if a small animal model could be developed for PRRSV, 3 strains of laboratory rodent were examined for their susceptibility to the virus. No virus replication was detected in BALB/c or SCID (severe combined immunodeficiency) mice after intraperitoneal inoculation. Moderate replication of PRRSV was detected in primary cotton rat lung cell cultures, but no viral replication was detected following intranasal or intraperitoneal inoculation. Following intratracheal inoculation, viral transcripts were detected in the lungs of cotton rats, but only for 1 day. This study indicates that PRRSV replication in common laboratory rodent species is inefficient, and suggests that a rodent model for this virus is not appropriate. PMID:20046635
-
Yamamoto, T.; Batts, W.N.; Arakawa, C.K.; Winton, J.R.
1990-01-01
The sites of replication of infectious hematopoietic necrosis virus (IHNV) in infected tissues were detected in fingerling rainbow trout Oncorhynchus mykiss by in situ histologic techniques following immersion infection. Virus antigens in tissues were detected by a neutralizing mouse monoclonal antibody and a one-step anti-mouse biotin-streptavidin conjugated to horseradish peroxidase. The efficiency of infection and virulence of the virus determined by mortality rates showed high virulence of the selected IHNV isolates, and viral replication in individual fish showed that virus content of the fish increased rapidly from the second day to the seventh day postinfection. The earliest viral lesions following infection were detected in the epidermis of the pectoral fins, opercula, and ventral surface of the body. Virus lesions became evident in kidneys on the third day. By the fifth day, when there was a significant increase in virus titer, foci of viral replication were detected in gill tissue and in the anterior internal tissues below the epidermis. Subsequently, extensive virus replication and tissue destruction were observed in the spleen, dorsal adipose tissues, ventricle, and pseudobranch. Replication in the liver, the muscularis layers of the digestive tract, and the general body musculature followed later. These infection experiments indicated that the epidermis and gills of fish constitute important sites of early IHNV replication.
-
Kautz, Tiffany F; Guerbois, Mathilde; Khanipov, Kamil; Yun, Ruimei; Warmbrod, Kelsey L; Fofanov, Yuriy; Weaver, Scott C; Forrester, Naomi L
2018-01-01
Abstract During RNA virus replication, there is the potential to incorporate mutations that affect virulence or pathogenesis. For live-attenuated vaccines, this has implications for stability, as replication may result in mutations that either restore the wild-type phenotype via reversion or compensate for the attenuating mutations by increasing virulence (pseudoreversion). Recent studies have demonstrated that altering the mutation rate of an RNA virus is an effective attenuation tool. To validate the safety of low-fidelity mutations to increase vaccine attenuation, several mutations in the RNA-dependent RNA-polymerase (RdRp) were tested in the live-attenuated Venezuelan equine encephalitis virus vaccine strain, TC-83. Next generation sequencing after passage in the presence of mutagens revealed a mutant containing three mutations in the RdRp, TC-83 3x, to have decreased replication fidelity, while a second mutant, TC-83 4x displayed no change in fidelity, but shared many phenotypic characteristics with TC-83 3x. Both mutants exhibited increased, albeit inconsistent attenuation in an infant mouse model, as well as increased immunogenicity and complete protection against lethal challenge of an adult murine model compared with the parent TC-83. During serial passaging in a highly permissive model, the mutants increased in virulence but remained less virulent than the parent TC-83. These results suggest that the incorporation of low-fidelity mutations into the RdRp of live-attenuated vaccines for RNA viruses can confer increased immunogenicity whilst showing some evidence of increased attenuation. However, while in theory such constructs may result in more effective vaccines, the instability of the vaccine phenotype decreases the likelihood of this being an effective vaccine strategy. PMID:29593882
-
Zika Virus RNA Replication and Persistence in Brain and Placental Tissue
Rabeneck, Demi B.; Martines, Roosecelis B.; Reagan-Steiner, Sarah; Ermias, Yokabed; Estetter, Lindsey B.C.; Suzuki, Tadaki; Ritter, Jana; Keating, M. Kelly; Hale, Gillian; Gary, Joy; Muehlenbachs, Atis; Lambert, Amy; Lanciotti, Robert; Oduyebo, Titilope; Meaney-Delman, Dana; Bolaños, Fernando; Saad, Edgar Alberto Parra; Shieh, Wun-Ju; Zaki, Sherif R.
2017-01-01
Zika virus is causally linked with congenital microcephaly and may be associated with pregnancy loss. However, the mechanisms of Zika virus intrauterine transmission and replication and its tropism and persistence in tissues are poorly understood. We tested tissues from 52 case-patients: 8 infants with microcephaly who died and 44 women suspected of being infected with Zika virus during pregnancy. By reverse transcription PCR, tissues from 32 (62%) case-patients (brains from 8 infants with microcephaly and placental/fetal tissues from 24 women) were positive for Zika virus. In situ hybridization localized replicative Zika virus RNA in brains of 7 infants and in placentas of 9 women who had pregnancy losses during the first or second trimester. These findings demonstrate that Zika virus replicates and persists in fetal brains and placentas, providing direct evidence of its association with microcephaly. Tissue-based reverse transcription PCR extends the time frame of Zika virus detection in congenital and pregnancy-associated infections. PMID:27959260
-
Replication of plant RNA virus genomes in a cell-free extract of evacuolated plant protoplasts
Komoda, Keisuke; Naito, Satoshi; Ishikawa, Masayuki
2004-01-01
The replication of eukaryotic positive-strand RNA virus genomes occurs through a complex process involving multiple viral and host proteins and intracellular membranes. Here we report a cell-free system that reproduces this process in vitro. This system uses a membrane-containing extract of uninfected plant protoplasts from which the vacuoles had been removed by Percoll gradient centrifugation. We demonstrate that the system supported translation, negative-strand RNA synthesis, genomic RNA replication, and subgenomic RNA transcription of tomato mosaic virus and two other plant positive-strand RNA viruses. The RNA synthesis, which depended on translation of the genomic RNA, produced virus-related RNA species similar to those that are generated in vivo. This system will aid in the elucidation of the mechanisms of genome replication in these viruses. PMID:14769932
-
Satellite RNAs of plant viruses: structures and biological effects.
Roossinck, M J; Sleat, D; Palukaitis, P
1992-01-01
Plant viruses often contain parasites of their own, referred to as satellites. Satellite RNAs are dependent on their associated (helper) virus for both replication and encapsidation. Satellite RNAs vary from 194 to approximately 1,500 nucleotides (nt). The larger satellites (900 to 1,500 nt) contain open reading frames and express proteins in vitro and in vivo, whereas the smaller satellites (194 to 700 nt) do not appear to produce functional proteins. The smaller satellites contain a high degree of secondary structure involving 49 to 73% of their sequences, with the circular satellites containing more base pairing than the linear satellites. Many of the smaller satellites produce multimeric forms during replication. There are various models to account for their formation and role in satellite replication. Some of these smaller satellites encode ribozymes and are able to undergo autocatalytic cleavage. The enzymology of satellite replication is poorly understood, as is the replication of their helper viruses. In many cases the coreplication of satellites suppresses the replication of the helper virus genome. This is usually paralleled by a reduction in the disease induced by the helper virus; however, there are notable exceptions in which the satellite exacerbates the pathogenicity of the helper virus, albeit on only a limited number of hosts. The ameliorative satellites are being assessed as biocontrol agents of virus-induced disease. In greenhouse studies, satellites have been known to "spontaneously" appear in virus cultures. The possible origin of satellites will be briefly considered. PMID:1620065
-
Debing, Yannick; Winton, James; Neyts, Johan; Dallmeier, Kai
2013-01-01
Hepatitis E virus (HEV) is one of the most important causes of acute hepatitis worldwide. Although most infections are self-limiting, mortality is particularly high in pregnant women. Chronic infections can occur in transplant and other immune-compromised patients. Successful treatment of chronic hepatitis E has been reported with ribavirin and pegylated interferon-alpha, however severe side effects were observed. We employed the cutthroat trout virus (CTV), a non-pathogenic fish virus with remarkable similarities to HEV, as a potential surrogate for HEV and established an antiviral assay against this virus using the Chinook salmon embryo (CHSE-214) cell line. Ribavirin and the respective trout interferon were found to efficiently inhibit CTV replication. Other known broad-spectrum inhibitors of RNA virus replication such as the nucleoside analog 2′-C-methylcytidine resulted only in a moderate antiviral activity. In its natural fish host, CTV levels largely fluctuate during the reproductive cycle with the virus detected mainly during spawning. We wondered whether this aspect of CTV infection may serve as a surrogate model for the peculiar pathogenesis of HEV in pregnant women. To that end the effect of three sex steroids on in vitro CTV replication was evaluated. Whereas progesterone resulted in marked inhibition of virus replication, testosterone and 17β-estradiol stimulated viral growth. Our data thus indicate that CTV may serve as a surrogate model for HEV, both for antiviral experiments and studies on the replication biology of the Hepeviridae.
-
Replication-Competent Controlled Herpes Simplex Virus
Bloom, David C.; Feller, Joyce; McAnany, Peterjon; Vilaboa, Nuria
2015-01-01
ABSTRACT We present the development and characterization of a replication-competent controlled herpes simplex virus 1 (HSV-1). Replication-essential ICP4 and ICP8 genes of HSV-1 wild-type strain 17syn+ were brought under the control of a dually responsive gene switch. The gene switch comprises (i) a transactivator that is activated by a narrow class of antiprogestins, including mifepristone and ulipristal, and whose expression is mediated by a promoter cassette that comprises an HSP70B promoter and a transactivator-responsive promoter and (ii) transactivator-responsive promoters that drive the ICP4 and ICP8 genes. Single-step growth experiments in different cell lines demonstrated that replication of the recombinant virus, HSV-GS3, is strictly dependent on an activating treatment consisting of administration of a supraphysiological heat dose in the presence of an antiprogestin. The replication-competent controlled virus replicates with an efficiency approaching that of the wild-type virus from which it was derived. Essentially no replication occurs in the absence of activating treatment or if HSV-GS3-infected cells are exposed only to heat or antiprogestin. These findings were corroborated by measurements of amounts of viral DNA and transcripts of the regulated ICP4 gene and the glycoprotein C (gC) late gene, which was not regulated. Similar findings were made in experiments with a mouse footpad infection model. IMPORTANCE The alphaherpesviruses have long been considered vectors for recombinant vaccines and oncolytic therapies. The traditional approach uses vector backbones containing attenuating mutations that restrict replication to ensure safety. The shortcoming of this approach is that the attenuating mutations tend to limit both the immune presentation and oncolytic properties of these vectors. HSV-GS3 represents a novel type of vector that, when activated, replicates with the efficiency of a nonattenuated virus and whose safety is derived from deliberate, stringent regulation of multiple replication-essential genes. By directing activating heat to the region of virus administration, replication is strictly confined to infected cells within this region. The requirement for antiprogestin provides an additional level of safety, ensuring that virus replication cannot be triggered inadvertently. Replication-competent controlled vectors such as HSV-GS3 may have the potential to be superior to conventional attenuated HSV vaccine and oncolytic vectors without sacrificing safety. PMID:26269179
-
Cell fusing agent virus and dengue virus mutually interact in Aedes aegypti cell lines.
Zhang, Guangmei; Asad, Sultan; Khromykh, Alexander A; Asgari, Sassan
2017-07-31
The genus Flavivirus contains more than 70 single-stranded, positive-sense arthropod-borne RNA viruses. Some flaviviruses are particularly medically important to humans and other vertebrates including dengue virus (DENV), West Nile virus, and yellow fever virus. These viruses are transmitted to vertebrates by mosquitoes and other arthropod species. Mosquitoes are also infected by insect-specific flaviviruses (ISFs) that do not appear to be infective to vertebrates. Cell fusing agent virus (CFAV) was the first described ISF, which was discovered in an Aedes aegypti cell culture. We found that while CFAV infection could be significantly reduced by application of RNAi against the NS5 gene, removal of the treatment led to quick restoration of CFAV replication. Interestingly, we found that CFAV infection significantly enhanced replication of DENV, and vice versa, DENV infection significantly enhanced replication of CFAV in mosquito cells. We have shown that CFAV infection leads to increase in the expression of ribonuclease kappa (RNASEK), which is known to promote infection of viruses that rely on endocytosis and pH-dependent entry. Knockdown of RNASEK by dsRNA resulted in reduced DENV replication. Thus, increased expression of RNASEK induced by CFAV is likely to contribute to enhanced DENV replication in CFAV-infected cells.
-
Cawood, Ryan; Chen, Hannah H; Carroll, Fionnadh; Bazan-Peregrino, Miriam; van Rooijen, Nico; Seymour, Leonard W
2009-05-01
Replicating viruses have broad applications in biomedicine, notably in cancer virotherapy and in the design of attenuated vaccines; however, uncontrolled virus replication in vulnerable tissues can give pathology and often restricts the use of potent strains. Increased knowledge of tissue-selective microRNA expression now affords the possibility of engineering replicating viruses that are attenuated at the RNA level in sites of potential pathology, but retain wild-type replication activity at sites not expressing the relevant microRNA. To assess the usefulness of this approach for the DNA virus adenovirus, we have engineered a hepatocyte-safe wild-type adenovirus 5 (Ad5), which normally mediates significant toxicity and is potentially lethal in mice. To do this, we have included binding sites for hepatocyte-selective microRNA mir-122 within the 3' UTR of the E1A transcription cassette. Imaging versions of these viruses, produced by fusing E1A with luciferase, showed that inclusion of mir-122 binding sites caused up to 80-fold decreased hepatic expression of E1A following intravenous delivery to mice. Animals administered a ten-times lethal dose of wild-type Ad5 (5x10(10) viral particles/mouse) showed substantial hepatic genome replication and extensive liver pathology, while inclusion of 4 microRNA binding sites decreased replication 50-fold and virtually abrogated liver toxicity. This modified wild-type virus retained full activity within cancer cells and provided a potent, liver-safe oncolytic virus. In addition to providing many potent new viruses for cancer virotherapy, microRNA control of virus replication should provide a new strategy for designing safe attenuated vaccines applied across a broad range of viral diseases.
-
Bilska, Miroslawa; Tang, Haili; Montefiori, David C
2017-04-01
Env-pseudotyped viruses are valuable reagents for studies of HIV-1 neutralizing antibodies. It is often assumed that all pseudovirus particles are capable of only a single round of infection, making them a safe alternative to work with live HIV-1. In this study, we show that some Env-pseudotyped virus preparations give rise to low levels of replication-competent virus. These levels did not compromise results in the TZM-bl neutralization assay; however, their presence highlights a need to adhere to the same level of biosafety when working with Env-pseudotyped viruses that are required for work with replication competent HIV-1.
-
See, Raymond H; Petric, Martin; Lawrence, David J; Mok, Catherine P Y; Rowe, Thomas; Zitzow, Lois A; Karunakaran, Karuna P; Voss, Thomas G; Brunham, Robert C; Gauldie, Jack; Finlay, B Brett; Roper, Rachel L
2008-09-01
Although the 2003 severe acute respiratory syndrome (SARS) outbreak was controlled, repeated transmission of SARS coronavirus (CoV) over several years makes the development of a SARS vaccine desirable. We performed a comparative evaluation of two SARS vaccines for their ability to protect against live SARS-CoV intranasal challenge in ferrets. Both the whole killed SARS-CoV vaccine (with and without alum) and adenovirus-based vectors encoding the nucleocapsid (N) and spike (S) protein induced neutralizing antibody responses and reduced viral replication and shedding in the upper respiratory tract and progression of virus to the lower respiratory tract. The vaccines also diminished haemorrhage in the thymus and reduced the severity and extent of pneumonia and damage to lung epithelium. However, despite high neutralizing antibody titres, protection was incomplete for all vaccine preparations and administration routes. Our data suggest that a combination of vaccine strategies may be required for effective protection from this pathogen. The ferret may be a good model for SARS-CoV infection because it is the only model that replicates the fever seen in human patients, as well as replicating other SARS disease features including infection by the respiratory route, clinical signs, viral replication in upper and lower respiratory tract and lung damage.
-
Lynch, Rebecca M; Yamamoto, Takuya; McDermott, Adrian B
2013-07-01
Here we highlight the latest advances in HIV vaccine concepts that will expand our knowledge on how to elicit effective acquisition-prevention and/or control of simian immunodeficiency virus (SIV) replication in the nonhuman primate (NHP) model. In the context of the promising analyses from the RV144 Thai Trial and the effective control of SIV replication exerted by rhCMV-(SIV) elicited EM CD8 T cells, the HIV field has recently shifted toward vaccine concepts that combine protection from acquisition with effective control of SIV replication. Current studies in the NHP model have demonstrated the efficacy of HIV-neutralizing antibodies via passive transfer, the potential importance of the CD4 Tfh subset, the ability to effectively model the RV144 vaccine trial and the capacity of an Ad26 prime and modified vaccinia Ankara virus boost to elicit Env-specific antibody and cellular responses that both limit acquisition and control heterologous SIVmac251 challenge. The latest work in the NHP model suggests that the next generation HIV-1 vaccines should aim to provoke a comprehensive adaptive immune response for both prevention of SIV acquisition as well as control of replication in breakthrough infection.
-
Differential effects of lipid biosynthesis inhibitors on Zika and Semliki Forest viruses.
Royle, Jamie; Donald, Claire L; Merits, Andres; Kohl, Alain; Varjak, Margus
2017-12-01
The recent outbreak of infection with Zika virus (ZIKV; Flaviviridae) has attracted attention to this previously neglected mosquito-borne pathogen and the need for efficient therapies. Since flavivirus replication is generally known to be dependent on fatty acid biosynthesis, two inhibitors of this pathway, 5-(tetradecyloxyl)-2-furoic acid (TOFA) and cerulenin, were tested for their potentiality to inhibit virus replication. At concentrations previously shown to inhibit the replication of other flaviviruses, neither drug had a significant antiviral affect against ZIKV, but reduced the replication of the non-related mosquito-borne Semliki Forest virus (Togaviridae). Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
-
Palù, Giorgio; Loregian, Arianna
2013-09-01
Protein-protein interactions (PPIs) play a key role in many biological processes, including virus replication in the host cell. Since most of the PPIs are functionally essential, a possible strategy to inhibit virus replication is based on the disruption of viral protein complexes by peptides or small molecules that interfere with subunit interactions. In particular, an attractive target for antiviral drugs is the binding between the subunits of essential viral enzymes. This review describes the development of new antiviral compounds that inhibit herpesvirus and influenza virus replication by blocking interactions between subunit proteins of their polymerase complexes. Copyright © 2013 Elsevier B.V. All rights reserved.
-
Holinka, L. G.; Largo, E.; Gladue, D. P.; O'Donnell, V.; Risatti, G. R.; Nieva, J. L.
2016-01-01
ABSTRACT E2, the major envelope glycoprotein of classical swine fever virus (CSFV), is involved in several critical virus functions, including cell attachment, host range susceptibility, and virulence in natural hosts. Functional structural analysis of E2 based on a Wimley-White interfacial hydrophobicity distribution predicted the involvement of a loop (residues 864 to 881) stabilized by a disulfide bond (869CKWGGNWTCV878, named FPII) in establishing interactions with the host cell membrane. This loop further contains an 872GG873 dipeptide, as well as two aromatic residues (871W and 875W) accessible to solvent. Reverse genetics utilizing a full-length infectious clone of the highly virulent CSFV strain Brescia (BICv) was used to evaluate how amino acid substitutions within FPII may affect replication of BICv in vitro and virus virulence in swine. Recombinant CSFVs containing mutations in different residues of FPII were constructed. A particular construct, harboring amino acid substitutions W871T, W875D, and V878T (FPII.2), demonstrated a significantly decreased ability to replicate in a swine cell line (SK6) and swine macrophage primary cell cultures. Interestingly, mutated virus FPII.2 was completely attenuated in pigs. Also, animals infected with FPII.2 virus were protected against virulent challenge with Brescia virus at 21 days postvaccination. Supporting a role for the E2 the loop from residues 864 to 881 in membrane fusion, only synthetic peptides that were based on the native E2 functional sequence were competent for insertion into model membranes and perturbation of their integrity, and this functionality was lost in synthetic peptides harboring amino acid substitutions W871T, W875D, and V878T in FPII.2. IMPORTANCE This report describes the identification and characterization of a putative fusion peptide (FP) in the major structural protein E2 of classical swine fever virus (CSFV). The FP identification was performed by functional structural analysis of E2. We characterized the functional significance of this FP by using artificial membranes. Replacement of critical amino acid residues within the FP radically alters how it interacts with the artificial membranes. When we introduced the same mutations into the viral sequence, there was a reduction in replication in cell cultures, and when we infected domestic swine, the natural host of CSFV host, we observed that the virus was now completely attenuated in swine. In addition, the virus mutant that was attenuated in vivo efficiently protected pigs against wild-type virus. These results provide the proof of principle to support as a strategy for vaccine development the discovery and manipulation of FPs. PMID:27605674
-
Adipose Tissue: Sanctuary for HIV/SIV Persistence and Replication.
Pallikkuth, Suresh; Mohan, Mahesh
2015-12-01
This commentary highlights new findings from a recent study identifying adipose tissue as a potential HIV reservoir and a major site of inflammation during chronic human/simian immunodeficiency virus (HIV/SIV) infection. A concise discussion about upcoming challenges and new research avenues for reducing chronic adipose inflammation during HIV/SIV infection is presented. Copyright © 2015 Elsevier Ltd. All rights reserved.
-
USDA-ARS?s Scientific Manuscript database
Replication-defective recombinant adenovirus 5 (rAd5) vectors carrying foot-and-mouth disease virus (FMDV) transgenes elicit a robust immune response to FMDV challenge in cattle; however vaccine function mechanisms are incompletely understood. Recent efforts addressing critical interactions of rAd5 ...
-
Hatta, Yasuko; Hershberger, Karen; Shinya, Kyoko; Proll, Sean C; Dubielzig, Richard R; Hatta, Masato; Katze, Michael G; Kawaoka, Yoshihiro; Suresh, M
2010-10-07
Since the first recorded infection of humans with H5N1 viruses of avian origin in 1997, sporadic human infections continue to occur with a staggering mortality rate of >60%. Although sustained human-to-human transmission has not occurred yet, there is a growing concern that these H5N1 viruses might acquire this trait and raise the specter of a pandemic. Despite progress in deciphering viral determinants of pathogenicity, we still lack crucial information on virus/immune system interactions pertaining to severe disease and high mortality associated with human H5N1 influenza virus infections. Using two human isolates of H5N1 viruses that differ in their pathogenicity in mice, we have defined mechanistic links among the rate of viral replication, mortality, CD8 T cell responses, and immunopathology. The extreme pathogenicity of H5N1 viruses was directly linked to the ability of the virus to replicate rapidly, and swiftly attain high steady-state titers in the lungs within 48 hours after infection. The remarkably high replication rate of the highly pathogenic H5N1 virus did not prevent the induction of IFN-β or activation of CD8 T cells, but the CD8 T cell response was ineffective in controlling viral replication in the lungs and CD8 T cell deficiency did not affect viral titers or mortality. Additionally, BIM deficiency ameliorated lung pathology and inhibited T cell apoptosis without affecting survival of mice. Therefore, rapidly replicating, highly lethal H5N1 viruses could simply outpace and overwhelm the adaptive immune responses, and kill the host by direct cytopathic effects. However, therapeutic suppression of early viral replication and the associated enhancement of CD8 T cell responses improved the survival of mice following a lethal H5N1 infection. These findings suggest that suppression of early H5N1 virus replication is key to the programming of an effective host response, which has implications in treatment of this infection in humans.
-
Zeshan, Basit; Zhang, Lili; Bai, Juan; Wang, Xinglong; Xu, Jiarong; Jiang, Ping
2010-06-01
In ovo vaccination remains an attractive option for a cost effective, uniform and mass application of vaccines for commercial poultry. However, the vaccines which can be delivered safely by this method are limited and there is no currently licensed embryo-safe vaccine against infectious bronchitis virus (IBV). In this study, a recombinant adenovirus expressing the S1 gene of nephropathogenic IBV (rAd-S1) was constructed and the immune responses and protective efficacy against homologous challenge were evaluated after in ovo vaccination. The results showed that the rAd-S1 led to dramatic augmentation of humoral and cellular responses in birds vaccinated in ovo followed by an intramuscular inoculation. Both IFN-gamma and IL-4 in chicken's lymphocytes were produced by this strategy. Following challenge with IBV, the chickens vaccinated with recombinant adenovirus showed fewer nephropathic lesions and less severe clinical signs as compared to those receiving wild-type adenovirus or PBS. The construction of non-replicating human adenovirus vector encoding S1 gene of IBV and its in ovo delivery demonstrated the potential of an alternative vaccination strategy against IBV. Copyright 2010 Elsevier B.V. All rights reserved.
-
Harandi, Ali M
2004-07-01
Herpes simplex virus type 2 (HSV-2) invades human genital tract mucosa and following local replications can be rapidly transmitted via peripheral nerve axons to the sacral ganglia where it can establish latency. Reactivation of the latent viral reservoir results in recurrent ulcers in the genital region. Innate immunity, the first line of defence during both primary and recurrent genital herpes infections, is crucial during the period of acute infection to limit early virus replication and to facilitate the development of an appropriate specific acquired immunity. Recent developments in immunology reveal that the mammalian innate immune systems use Toll-like receptor (TLR) to specifically sense evolutionary conserved molecules such as bacterial DNA in pathogens. Recently, local-vaginal delivery of CpG containing oligodeoxynucleotide (ODN), a synthetic mimic of bacterial DNA, holds substantial promise as a strong inducer of innate immunity against genital herpes infections in the animal models of the disease. These preclinical observations provide a scientific ground work for introduction of this novel intervention strategy to clinic. This review aims to highlight recent developments and future challenges in use of immunostimulatory CpG ODN for inducing immunity against genital herpes infection and disease.
-
Suppression of Poxvirus Replication by Resveratrol.
Cao, Shuai; Realegeno, Susan; Pant, Anil; Satheshkumar, Panayampalli S; Yang, Zhilong
2017-01-01
Poxviruses continue to cause serious diseases even after eradication of the historically deadly infectious human disease, smallpox. Poxviruses are currently being developed as vaccine vectors and cancer therapeutic agents. Resveratrol is a natural polyphenol stilbenoid found in plants that has been shown to inhibit or enhance replication of a number of viruses, but the effect of resveratrol on poxvirus replication is unknown. In the present study, we found that resveratrol dramatically suppressed the replication of vaccinia virus (VACV), the prototypic member of poxviruses, in various cell types. Resveratrol also significantly reduced the replication of monkeypox virus, a zoonotic virus that is endemic in Western and Central Africa and causes human mortality. The inhibitory effect of resveratrol on poxviruses is independent of VACV N1 protein, a potential resveratrol binding target. Further experiments demonstrated that resveratrol had little effect on VACV early gene expression, while it suppressed VACV DNA synthesis, and subsequently post-replicative gene expression.
-
Replication of swine and human influenza viruses in juvenile and layer turkey hens.
Ali, Ahmed; Yassine, Hadi; Awe, Olusegun O; Ibrahim, Mahmoud; Saif, Yehia M; Lee, Chang-Won
2013-04-12
Since the first reported isolation of swine influenza viruses (SIVs) in turkeys in the 1980s, transmission of SIVs to turkeys was frequently documented. Recently, the 2009 pandemic H1N1 virus, that was thought to be of swine origin, was detected in turkeys with a severe drop in egg production. In this study, we assessed the infectivity of different mammalian influenza viruses including swine, pandemic H1N1 and seasonal human influenza viruses in both juvenile and layer turkeys. In addition, we investigated the potential influenza virus dissemination in the semen of experimentally infected turkey toms. Results showed that all mammalian origin influenza viruses tested can infect turkeys. SIVs were detected in respiratory and digestive tracts of both juvenile and layer turkeys. Variations in replication efficiencies among SIVs were observed especially in the reproductive tract of layer turkeys. Compared to SIVs, limited replication of seasonal human H1N1 and no detectable replication of recent human-like swine H1N2, pandemic H1N1 and seasonal human H3N2 viruses was noticed. All birds seroconverted to all tested viruses regardless of their replication level. In turkey toms, we were able to detect swine H3N2 virus in semen and reproductive tract of infected toms by real-time RT-PCR although virus isolation was not successful. These data suggest that turkey hens could be affected by diverse influenza strains especially SIVs. Moreover, the differences in the replication efficiency we demonstrated among SIVs and between SIV and human influenza viruses in layer turkeys suggest a possible use of turkeys as an animal model to study host tropism and pathogenesis of influenza viruses. Our results also indicate a potential risk of venereal transmission of influenza viruses in turkeys. Copyright © 2012 Elsevier B.V. All rights reserved.
-
Yang, Darong; Zuo, Chaohui; Wang, Xiaohong; Meng, Xianghe; Xue, Binbin; Liu, Nianli; Yu, Rong; Qin, Yuwen; Gao, Yimin; Wang, Qiuping; Hu, Jun; Wang, Ling; Zhou, Zebin; Liu, Bing; Tan, Deming; Guan, Yang; Zhu, Haizhen
2014-04-01
The absence of a robust cell culture system for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection has limited the analysis of the virus lifecycle and drug discovery. We have established a hepatoma cell line, HLCZ01, the first cell line, to the authors' knowledge, supporting the entire lifecycle of both HBV and HCV. HBV surface antigen (HBsAg)-positive particles can be observed in the supernatant and the lumen of the endoplasmic reticulum of the cells via electron microscopy. Interestingly, HBV and HCV clinical isolates propagate in HLCZ01 cells. Both viruses replicate in the cells without evidence of overt interference. HBV and HCV entry are blocked by antibodies against HBsAg and human CD81, respectively, and the replication of HBV and HCV is inhibited by antivirals. HLCZ01 cells mount an innate immune response to virus infection. The cell line provides a powerful tool for exploring the mechanisms of virus entry and replication and the interaction between host and virus, facilitating the development of novel antiviral agents and vaccines.
-
Chronic and persistent viral hemorrhagic septicemia virus infections in Pacific herring
Hershberger, P.K.; Gregg, J.L.; Grady, C.A.; Taylor, L.; Winton, J.R.
2010-01-01
Chronic viral hemorrhagic septicemia virus (VHSV) infections were established in a laboratory stock of Pacific herring Clupea pallasii held in a large-volume tank supplied with pathogenfree seawater at temperatures ranging from 6.8 to 11.6??C. The infections were characterized by viral persistence for extended periods and near-background levels of host mortality. Infectious virus was recovered from mortalities occurring up to 167 d post-exposure and was detected in normal-appearing herring for as long as 224 d following initial challenge. Geometric mean viral titers were generally as high as or higher in brain tissues than in pools of kidney and spleen tissues, with overall prevalence of infection being higher in the brain. Upon re-exposure to VHSV in a standard laboratory challenge, negligible mortality occurred among groups of herring that were either chronically infected or fully recovered, indicating that survival from chronic manifestations conferred protection against future disease. However, some survivors of chronic VHS infections were capable of replicating virus upon re-exposure. Demonstration of a chronic manifestation of VHSV infection among Pacific herring maintained at ambient seawater temperatures provides insights into the mechanisms by which the virus is maintained among populations of endemic hosts. ?? 2010 Inter-Research.
-
Chronic and persistent viral hemorrhagic septicemia virus infections in Pacific herring
Hershberger, Paul K.; Gregg, Jacob L.; Winton, James R.; Grady, Cortney A.; Taylor, L.
2010-01-01
Chronic viral hemorrhagic septicemia virus (VHSV) infections were established in a laboratory stock of Pacific herring Clupea pallasii held in a large-volume tank supplied with pathogen-free seawater at temperatures ranging from 6.8 to 11.6°C. The infections were characterized by viral persistence for extended periods and near-background levels of host mortality. Infectious virus was recovered from mortalities occurring up to 167 d post-exposure and was detected in normal-appearing herring for as long as 224 d following initial challenge. Geometric mean viral titers were generally as high as or higher in brain tissues than in pools of kidney and spleen tissues, with overall prevalence of infection being higher in the brain. Upon re-exposure to VHSV in a standard laboratory challenge, negligible mortality occurred among groups of herring that were either chronically infected or fully recovered, indicating that survival from chronic manifestations conferred protection against future disease. However, some survivors of chronic VHS infections were capable of replicating virus upon re-exposure. Demonstration of a chronic manifestation of VHSV infection among Pacific herring maintained at ambient seawater temperatures provides insights into the mechanisms by which the virus is maintained among populations of endemic hosts.
-
Oncolytic viruses: a new class of immunotherapy drugs.
Kaufman, Howard L; Kohlhapp, Frederick J; Zloza, Andrew
2015-09-01
Oncolytic viruses represent a new class of therapeutic agents that promote anti-tumour responses through a dual mechanism of action that is dependent on selective tumour cell killing and the induction of systemic anti-tumour immunity. The molecular and cellular mechanisms of action are not fully elucidated but are likely to depend on viral replication within transformed cells, induction of primary cell death, interaction with tumour cell antiviral elements and initiation of innate and adaptive anti-tumour immunity. A variety of native and genetically modified viruses have been developed as oncolytic agents, and the approval of the first oncolytic virus by the US Food and Drug Administration (FDA) is anticipated in the near future. This Review provides a comprehensive overview of the basic biology supporting oncolytic viruses as cancer therapeutic agents, describes oncolytic viruses in advanced clinical trials and discusses the unique challenges in the development of oncolytic viruses as a new class of drugs for the treatment of cancer.
-
Are viruses alive? The replicator paradigm sheds decisive light on an old but misguided question
Koonin, Eugene V.; Starokadomskyy, Petro
2016-01-01
The question whether or not “viruses are alive” has caused considerable debate over many years. Yet, the question is effectively without substance because the answer depends entirely on the definition of life or the state of “being alive” that is bound to be arbitrary. In contrast, the status of viruses among biological entities is readily defined within the replicator paradigm. All biological replicators form a continuum along the selfishness-cooperativity axis, from the completely selfish to fully cooperative forms. Within this range, typical, lytic viruses represent the selfish extreme whereas temperate viruses and various mobile elements occupy positions closer to the middle of the range. Selfish replicators not only belong to the biological realm but are intrinsic to any evolving system of replicators. No such system can evolve without the emergence of parasites, and moreover, parasites drive the evolution of biological complexity at multiple levels. The history of life is a story of parasite-host coevolution that includes both the incessant arms race and various forms of cooperation. All organisms are communities of interacting, coevolving replicators of different classes. A complete theory of replicator coevolution remains to be developed, but it appears likely that not only the differentiation between selfish and cooperative replicators but the emergence of the entire range of replication strategies, from selfish to cooperative, is intrinsic to biological evolution. PMID:26965225
-
Phosphatidic Acid Produced by Phospholipase D Promotes RNA Replication of a Plant RNA Virus
Hyodo, Kiwamu; Taniguchi, Takako; Manabe, Yuki; Kaido, Masanori; Mise, Kazuyuki; Sugawara, Tatsuya; Taniguchi, Hisaaki; Okuno, Tetsuro
2015-01-01
Eukaryotic positive-strand RNA [(+)RNA] viruses are intracellular obligate parasites replicate using the membrane-bound replicase complexes that contain multiple viral and host components. To replicate, (+)RNA viruses exploit host resources and modify host metabolism and membrane organization. Phospholipase D (PLD) is a phosphatidylcholine- and phosphatidylethanolamine-hydrolyzing enzyme that catalyzes the production of phosphatidic acid (PA), a lipid second messenger that modulates diverse intracellular signaling in various organisms. PA is normally present in small amounts (less than 1% of total phospholipids), but rapidly and transiently accumulates in lipid bilayers in response to different environmental cues such as biotic and abiotic stresses in plants. However, the precise functions of PLD and PA remain unknown. Here, we report the roles of PLD and PA in genomic RNA replication of a plant (+)RNA virus, Red clover necrotic mosaic virus (RCNMV). We found that RCNMV RNA replication complexes formed in Nicotiana benthamiana contained PLDα and PLDβ. Gene-silencing and pharmacological inhibition approaches showed that PLDs and PLDs-derived PA are required for viral RNA replication. Consistent with this, exogenous application of PA enhanced viral RNA replication in plant cells and plant-derived cell-free extracts. We also found that a viral auxiliary replication protein bound to PA in vitro, and that the amount of PA increased in RCNMV-infected plant leaves. Together, our findings suggest that RCNMV hijacks host PA-producing enzymes to replicate. PMID:26020241
-
Nicolas, Armel; Alazard-Dany, Nathalie; Biollay, Coline; Arata, Loredana; Jolinon, Nelly; Kuhn, Lauriane; Ferro, Myriam; Weller, Sandra K; Epstein, Alberto L; Salvetti, Anna; Greco, Anna
2010-09-01
Adeno-associated virus (AAV) is a human parvovirus that replicates only in cells coinfected with a helper virus, such as adenovirus or herpes simplex virus type 1 (HSV-1). We previously showed that nine HSV-1 factors are able to support AAV rep gene expression and genome replication. To elucidate the strategy of AAV replication in the presence of HSV-1, we undertook a proteomic analysis of cellular and HSV-1 factors associated with Rep proteins and thus potentially recruited within AAV replication compartments (AAV RCs). This study resulted in the identification of approximately 60 cellular proteins, among which factors involved in DNA and RNA metabolism represented the largest functional categories. Validation analyses indicated that the cellular DNA replication enzymes RPA, RFC, and PCNA were recruited within HSV-1-induced AAV RCs. Polymerase delta was not identified but subsequently was shown to colocalize with Rep within AAV RCs even in the presence of the HSV-1 polymerase complex. In addition, we found that AAV replication is associated with the recruitment of components of the Mre11/Rad50/Nbs1 complex, Ku70 and -86, and the mismatch repair proteins MSH2, -3, and -6. Finally, several HSV-1 factors were also found to be associated with Rep, including UL12. We demonstrated for the first time that this protein plays a role during AAV replication by enhancing the resolution of AAV replicative forms and AAV particle production. Altogether, these analyses provide the basis to understand how AAV adapts its replication strategy to the nuclear environment induced by the helper virus.
-
Liu, XueQiao
2014-01-01
Programmed cell death (apoptosis) is an important host defense mechanism against intracellular pathogens, such as viruses. Accordingly, viruses have evolved multiple mechanisms to modulate apoptosis to enhance replication. Varicella-zoster virus (VZV) induces apoptosis in human fibroblasts and melanoma cells. We found that VZV triggered the phosphorylation of the proapoptotic proteins Bim and BAD but had little or no effect on other Bcl-2 family members. Since phosphorylation of Bim and BAD reduces their proapoptotic activity, this may prevent or delay apoptosis in VZV-infected cells. Phosphorylation of Bim but not BAD in VZV-infected cells was dependent on activation of the MEK/extracellular signal-regulated kinase (ERK) pathway. Cells knocked down for Bim showed delayed VZV plaque formation, resulting in longer survival of VZV-infected cells and increased replication of virus, compared with wild-type cells infected with virus. Conversely, overexpression of Bim resulted in earlier plaque formation, smaller plaques, reduced virus replication, and increased caspase 3 activity. Inhibition of caspase activity in VZV-infected cells overexpressing Bim restored levels of virus production similar to those seen with virus-infected wild-type cells. Previously we showed that VZV ORF12 activates ERK and inhibits apoptosis in virus-infected cells. Here we found that VZV ORF12 contributes to Bim and BAD phosphorylation. In summary, VZV triggers Bim phosphorylation; reduction of Bim levels results in longer survival of VZV-infected cells and increased VZV replication. PMID:24227856
-
Griffiths, Samantha J.; Haas, Jürgen
2017-01-01
Varicella zoster virus (VZV) is a human herpesvirus which causes Varicella (chickenpox) upon primary infection and Zoster (shingles) following reactivation from latency (von Bokay, 1909). Whilst VZV is extensively studied, inherent features of VZV replication, such as cell-association of virus particles during in vitro culture and a restricted host range (limited to humans and some other primates) mean the cellular and viral mechanisms underlying VZV reactivation and pathogenesis remain largely uncharacterised. Much remains to be learnt about VZV, interactions with its host, and the development of disease. This protocol describes a basic VZV replication assay using a recombinant VZV-GFP reporter virus. As VZV is highly cell-associated in tissue culture, the reporter virus inoculum described here is a preparation of infected cells. This reporter virus-infected cell line can be used in combination with siRNA gene depletion or cDNA overexpression transfection protocols to determine the effect of individual cellular genes on virus replication. PMID:29085851
-
Fujimoto, Yoshikazu; Ito, Hiroshi; Ono, Etsuro; Kawaoka, Yoshihiro; Ito, Toshihiro
2016-04-01
Influenza A viruses are known to primarily replicate in duck intestine following infection via the oral route, but the specific role of neuraminidase (NA) for the intestinal tropism of influenza A viruses has been unclear. A reassortant virus (Dk78/Eng62N2) did not propagate in ducks infected via the oral route. To generate variant viruses that grow well in ducks via the oral route, we isolated viruses that effectively replicate in intestinal mucosal cells by passaging Dk78/Eng62N2 in duck via rectal-route infection. This procedure led to the isolation of a variant virus from the duck intestine. This virus was propagated using embryonated chicken eggs and inoculated into a duck via the oral route, which led to the isolation of Dk-rec6 from the duck intestine. Experimental infections with mutant viruses generated by using reverse genetics indicated that the paired mutation of residues 356 and 431 in NA was necessary for the viral replication in duck intestine. The NA assay revealed that the activity of Dk78/Eng62N2 almost disappeared after pH 3 treatment, whereas that of Dk-rec6 was maintained. Furthermore, to identify the amino acid residues associated with the low-pH resistance, we measured the activities of mutant NA proteins transiently expressed in 293 cells after pH 3 treatment. All mutant NA proteins that possessed proline at position 431 showed higher activities than NA proteins that possessed glutamine at this position. These findings indicate that the low-pH resistance of NA plays an important role in the ability of influenza A virus to replicate in duck intestine. Neuraminidase (NA) activity facilitates the release of viruses from cells and, as such, is important for the replicative efficiency of influenza A virus. Ducks are believed to serve as the principal natural reservoir for influenza A virus; however, the key properties of NA for viral infection in duck are not well understood. In this study, we identify amino acid residues in NA that contribute to viral replication in ducks via the natural route of infection and demonstrate that maintenance of NA activity under low-pH conditions is associated with the biological properties of the virus. These findings provide insights into the mechanisms of replication of influenza A virus in ducks. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
-
Poole, Daniel S.; Yú, Shuǐqìng; Caì, Yíngyún; Dinis, Jorge M.; Müller, Marcel A.; Jordan, Ingo; Friedrich, Thomas C.; Kuhn, Jens H.
2014-01-01
ABSTRACT The recent identification of highly divergent influenza A viruses in bats revealed a new, geographically dispersed viral reservoir. To investigate the molecular mechanisms of host-restricted viral tropism and the potential for transmission of viruses between humans and bats, we exposed a panel of cell lines from bats of diverse species to a prototypical human-origin influenza A virus. All of the tested bat cell lines were susceptible to influenza A virus infection. Experimental evolution of human and avian-like viruses in bat cells resulted in efficient replication and created highly cytopathic variants. Deep sequencing of adapted human influenza A virus revealed a mutation in the PA polymerase subunit not previously described, M285K. Recombinant virus with the PA M285K mutation completely phenocopied the adapted virus. Adaptation of an avian virus-like virus resulted in the canonical PB2 E627K mutation that is required for efficient replication in other mammals. None of the adaptive mutations occurred in the gene for viral hemagglutinin, a gene that frequently acquires changes to recognize host-specific variations in sialic acid receptors. We showed that human influenza A virus uses canonical sialic acid receptors to infect bat cells, even though bat influenza A viruses do not appear to use these receptors for virus entry. Our results demonstrate that bats are unique hosts that select for both a novel mutation and a well-known adaptive mutation in the viral polymerase to support replication. IMPORTANCE Bats constitute well-known reservoirs for viruses that may be transferred into human populations, sometimes with fatal consequences. Influenza A viruses have recently been identified in bats, dramatically expanding the known host range of this virus. Here we investigated the replication of human influenza A virus in bat cell lines and the barriers that the virus faces in this new host. Human influenza A and B viruses infected cells from geographically and evolutionarily diverse New and Old World bats. Viruses mutated during infections in bat cells, resulting in increased replication and cytopathic effects. These mutations were mapped to the viral polymerase and shown to be solely responsible for adaptation to bat cells. Our data suggest that replication of human influenza A viruses in a nonnative host drives the evolution of new variants and may be an important source of genetic diversity. PMID:25142579
-
Amann, Ralf; Rohde, Jörg; Wulle, Ulrich; Conlee, Douglas; Raue, Rudiger; Martinon, Olivier; Rziha, Hanns-Joachim
2013-02-01
The present study describes the generation of a new Orf virus (ORFV) recombinant, D1701-V-RabG, expressing the rabies virus (RABV) glycoprotein that is correctly presented on the surface of infected cells without the need of replication or production of infectious recombinant virus. One single immunization with recombinant ORFV can stimulate high RABV-specific virus-neutralizing antibody (VNA) titers in mice, cats, and dogs, representing all nonpermissive hosts for the ORFV vector. The protective immune response against severe lethal challenge infection was analyzed in detail in mice using different dosages, numbers, and routes for immunization with the ORFV recombinant. Long-term levels of VNA could be elicited that remained greater than 0.5 IU per ml serum, indicative for the protective status. Single applications of higher doses (10(7) PFU) can be sufficient to confer complete protection against intracranial (i.c.) challenge, whereas booster immunization was needed for protection by the application of lower dosages. Anamnestic immune responses were achieved by each of the seven tested routes of inoculation, including oral application. Finally, in vivo antibody-mediated depletion of CD4-positive and/or CD8-posititve T cell subpopulations during immunization and/or challenge infection attested the importance of CD4 T cells for the induction of protective immunity by D1701-V-RabG. This report demonstrates another example of the potential of the ORFV vector and also indicates the capability of the new recombinant for vaccination of animals.
-
Amann, Ralf; Rohde, Jörg; Wulle, Ulrich; Conlee, Douglas; Raue, Rudiger; Martinon, Olivier
2013-01-01
The present study describes the generation of a new Orf virus (ORFV) recombinant, D1701-V-RabG, expressing the rabies virus (RABV) glycoprotein that is correctly presented on the surface of infected cells without the need of replication or production of infectious recombinant virus. One single immunization with recombinant ORFV can stimulate high RABV-specific virus-neutralizing antibody (VNA) titers in mice, cats, and dogs, representing all nonpermissive hosts for the ORFV vector. The protective immune response against severe lethal challenge infection was analyzed in detail in mice using different dosages, numbers, and routes for immunization with the ORFV recombinant. Long-term levels of VNA could be elicited that remained greater than 0.5 IU per ml serum, indicative for the protective status. Single applications of higher doses (107 PFU) can be sufficient to confer complete protection against intracranial (i.c.) challenge, whereas booster immunization was needed for protection by the application of lower dosages. Anamnestic immune responses were achieved by each of the seven tested routes of inoculation, including oral application. Finally, in vivo antibody-mediated depletion of CD4-positive and/or CD8-posititve T cell subpopulations during immunization and/or challenge infection attested the importance of CD4 T cells for the induction of protective immunity by D1701-V-RabG. This report demonstrates another example of the potential of the ORFV vector and also indicates the capability of the new recombinant for vaccination of animals. PMID:23175365
-
Park, Su-Jin; Si, Young-Jae; Kim, Jihye; Song, Min-Suk; Kim, Se-Mi; Kim, Eun-Ha; Kwon, Hyeok-Il; Kim, Young-Il; Lee, Ok-Jun; Shin, Ok Sarah; Kim, Chul-Joong; Shin, Eui-Cheol; Choi, Young Ki
2016-11-01
To investigate cross-protective vaccine efficacy of highly-pathogenic avian influenza H5N1 viruses against a recent HPAI H5N8 virus, we immunized C57BL/6 mice and ferrets with three alum-adjuvanted inactivated whole H5N1 vaccines developed through reverse-genetics (Rg): [Vietnam/1194/04xPR8 (clade 1), Korea/W149/06xPR8 (clade 2.2), and Korea/ES223N/03xPR8 (clade 2.5)]. Although relatively low cross-reactivities (10-40 HI titer) were observed against heterologous H5N8 virus, immunized animals were 100% protected from challenge with the 20 mLD50 of H5N8 virus, with the exception of mice vaccinated with 3.5μg of Rg Vietnam/1194/04xPR8. Of note, the Rg Korea/ES223N/03xPR8 vaccine provided not only effective protection, but also markedly inhibited viral replication in the lungs and nasal swabs of vaccine recipients within five days of HPAI H5N8 virus challenge. Further, we demonstrated that antibody-dependent cell-mediated cytotoxicity (ADCC) of an antibody-coated target cell by cytotoxic effector cells also plays a role in the heterologous protection of H5N1 vaccines against H5N8 challenge. Copyright © 2016 Elsevier Inc. All rights reserved.
-
MicroRNA regulation of human protease genes essential for influenza virus replication.
Meliopoulos, Victoria A; Andersen, Lauren E; Brooks, Paula; Yan, Xiuzhen; Bakre, Abhijeet; Coleman, J Keegan; Tompkins, S Mark; Tripp, Ralph A
2012-01-01
Influenza A virus causes seasonal epidemics and periodic pandemics threatening the health of millions of people each year. Vaccination is an effective strategy for reducing morbidity and mortality, and in the absence of drug resistance, the efficacy of chemoprophylaxis is comparable to that of vaccines. However, the rapid emergence of drug resistance has emphasized the need for new drug targets. Knowledge of the host cell components required for influenza replication has been an area targeted for disease intervention. In this study, the human protease genes required for influenza virus replication were determined and validated using RNA interference approaches. The genes validated as critical for influenza virus replication were ADAMTS7, CPE, DPP3, MST1, and PRSS12, and pathway analysis showed these genes were in global host cell pathways governing inflammation (NF-κB), cAMP/calcium signaling (CRE/CREB), and apoptosis. Analyses of host microRNAs predicted to govern expression of these genes showed that eight miRNAs regulated gene expression during virus replication. These findings identify unique host genes and microRNAs important for influenza replication providing potential new targets for disease intervention strategies.
-
Rapid Engineering of Foot-and-Mouth Disease Vaccine and Challenge Viruses
Lee, Seo-Yong; Lee, Yeo-Joo; Kim, Rae-Hyung; Park, Jeong-Nam; Park, Min-Eun; Ko, Mi-Kyeong; Choi, Joo-Hyung; Chu, Jia-Qi; Lee, Kwang-Nyeong; Kim, Su-Mi; Tark, Dongseob; Lee, Hyang-Sim; Ko, Young-Joon; Seo, Min-Goo; Park, Jung-Won; Kim, Byounghan; Lee, Myoung-Heon
2017-01-01
ABSTRACT There are seven antigenically distinct serotypes of foot-and-mouth disease virus (FMDV), each of which has intratypic variants. In the present study, we have developed methods to efficiently generate promising vaccines against seven serotypes or subtypes. The capsid-encoding gene (P1) of the vaccine strain O1/Manisa/Turkey/69 was replaced with the amplified or synthetic genes from the O, A, Asia1, C, SAT1, SAT2, and SAT3 serotypes. Viruses of the seven serotype were rescued successfully. Each chimeric FMDV with a replacement of P1 showed serotype-specific antigenicity and varied in terms of pathogenesis in pigs and mice. Vaccination of pigs with an experimental trivalent vaccine containing the inactivated recombinants based on the main serotypes O, A, and Asia1 effectively protected them from virus challenge. This technology could be a potential strategy for a customized vaccine with challenge tools to protect against epizootic disease caused by specific serotypes or subtypes of FMDV. IMPORTANCE Foot-and-mouth disease (FMD) virus (FMDV) causes significant economic losses. For vaccine preparation, the selection of vaccine strains was complicated by high antigenic variation. In the present study, we suggested an effective strategy to rapidly prepare and evaluate mass-produced customized vaccines against epidemic strains. The P1 gene encoding the structural proteins of the well-known vaccine virus was replaced by the synthetic or amplified genes of viruses of seven representative serotypes. These chimeric viruses generally replicated readily in cell culture and had a particle size similar to that of the original vaccine strain. Their antigenicity mirrored that of the original serotype from which their P1 gene was derived. Animal infection experiments revealed that the recombinants varied in terms of pathogenicity. This strategy will be a useful tool for rapidly generating customized FMD vaccines or challenge viruses for all serotypes, especially for FMD-free countries, which have prohibited the import of FMDVs. PMID:28566375
-
Rapid Engineering of Foot-and-Mouth Disease Vaccine and Challenge Viruses.
Lee, Seo-Yong; Lee, Yeo-Joo; Kim, Rae-Hyung; Park, Jeong-Nam; Park, Min-Eun; Ko, Mi-Kyeong; Choi, Joo-Hyung; Chu, Jia-Qi; Lee, Kwang-Nyeong; Kim, Su-Mi; Tark, Dongseob; Lee, Hyang-Sim; Ko, Young-Joon; Seo, Min-Goo; Park, Jung-Won; Kim, Byounghan; Lee, Myoung-Heon; Lee, Jong-Soo; Park, Jong-Hyeon
2017-08-15
There are seven antigenically distinct serotypes of foot-and-mouth disease virus (FMDV), each of which has intratypic variants. In the present study, we have developed methods to efficiently generate promising vaccines against seven serotypes or subtypes. The capsid-encoding gene (P1) of the vaccine strain O1/Manisa/Turkey/69 was replaced with the amplified or synthetic genes from the O, A, Asia1, C, SAT1, SAT2, and SAT3 serotypes. Viruses of the seven serotype were rescued successfully. Each chimeric FMDV with a replacement of P1 showed serotype-specific antigenicity and varied in terms of pathogenesis in pigs and mice. Vaccination of pigs with an experimental trivalent vaccine containing the inactivated recombinants based on the main serotypes O, A, and Asia1 effectively protected them from virus challenge. This technology could be a potential strategy for a customized vaccine with challenge tools to protect against epizootic disease caused by specific serotypes or subtypes of FMDV. IMPORTANCE Foot-and-mouth disease (FMD) virus (FMDV) causes significant economic losses. For vaccine preparation, the selection of vaccine strains was complicated by high antigenic variation. In the present study, we suggested an effective strategy to rapidly prepare and evaluate mass-produced customized vaccines against epidemic strains. The P1 gene encoding the structural proteins of the well-known vaccine virus was replaced by the synthetic or amplified genes of viruses of seven representative serotypes. These chimeric viruses generally replicated readily in cell culture and had a particle size similar to that of the original vaccine strain. Their antigenicity mirrored that of the original serotype from which their P1 gene was derived. Animal infection experiments revealed that the recombinants varied in terms of pathogenicity. This strategy will be a useful tool for rapidly generating customized FMD vaccines or challenge viruses for all serotypes, especially for FMD-free countries, which have prohibited the import of FMDVs. Copyright © 2017 Lee et al.
-
USDA-ARS?s Scientific Manuscript database
Bean pod mottle virus (BPMV) is a bipartite, positive-sense (+) RNA plant virus of the family Secoviridae. Its RNA1 encodes all proteins needed for genome replication and is capable of autonomous replication. By contrast, BPMV RNA2 must utilize RNA1-encoded proteins for replication. Here, we sought ...
-
Sakaguchi, M; Urakawa, T; Hirayama, Y; Miki, N; Yamamoto, M; Zhu, G S; Hirai, K
1993-07-01
The open reading frame (ORF) of 1206 bp within the short unique region (Us) of Marek's disease virus type 1 (MDV1) shows significant homology with the herpes simplex virus type 1 US3 gene encoding protein kinase (PK). The lacZ gene of Escherichia coli was inserted within the ORF, designated MDV1-US3, of MDV1 K544 strain DNA by homologous recombination. The plaque-purified recombinant MDV1 stably expressed the beta-galactosidase encoded by the inserted lacZ gene in infected cells and replicated well as the parental K544 strain. Antibodies against both MDV1 antigen and beta-galactosidase were detected in the sera of chickens immunized with recombinant MDV1. Chickens vaccinated with the recombinant MDV1 were protected from challenge with virulent MDV1. The MDV1 US3 gene expressed by a baculovirus vector encoded a 44-kDa protein. Mouse antisera against the 44-kDa protein reacted with two proteins of 44 and 45 kDa in extracts of cells infected with MDV1 but not with MDV types 2 or 3. The PK activity was detected in immune complexes of the anti-44-kDa sera with extracts of cells infected with MDV1 but not with the recombinant MDV1. Thus, PK encoded from the MDV1-US3 is not essential for virus replication in cell culture and vaccine-induced immunity.
-
Drew, T W
2011-04-01
Over the last 20 years, pig production has been characterised by a rapid increase in the volume of pig meat produced, greater intensification of the pig-rearing process and much greater international movement of products. There have also been many novel viral diseases that challenge the industry. Are these two developments linked and, if so, how? To understand how changes in the industry may influence the evolution of viruses, it is important to understand something of evolutionary theory. For RNA viruses, the concept of 'quasispecies' has moved solidly from theory to fact. Such viruses do not exist as a single entity, but as a 'cloud' of viruses, whose degree of diversity is influenced by a number of factors. Chief among these are the size and rate of the replicating population, along with the availability and diversity of susceptible hosts. A feature of RNA viruses is a high level of mutation, due to lack of capability to correct errors on the part of the host cell. Both in vivo and in vitro, RNA viruses have been shown to accumulate and fix these mutations, leading to bottleneck events and fitness loss, the phenomenon known as'Muller's ratchet'. Likewise, the opposite effect, fitness gain, can be achieved in an environment providing for high levels of replication and the generation of large populations of virus. This has been shown to be possible in vitro by high-volume passage. It is possible that the regular introduction of diverse viruses within large-scale pig production provides an in vivo equivalent that could drive quasispecies populations to increased fitness, and may explain why emergent viruses, either new to science or with new synergies and presentation, seem to be appearing more commonly.
-
Izuogu, Adaeze O; McNally, Kristin L; Harris, Stephen E; Youseff, Brian H; Presloid, John B; Burlak, Christopher; Munshi-South, Jason; Best, Sonja M; Taylor, R Travis
2017-01-01
Tick-borne flaviviruses (TBFVs), including Powassan virus and tick-borne encephalitis virus cause encephalitis or hemorrhagic fevers in humans with case-fatality rates ranging from 1-30%. Despite severe disease in humans, TBFV infection of natural rodent hosts has little noticeable effect. Currently, the basis for resistance to disease is not known. We hypothesize that the coevolution of flaviviruses with their respective hosts has shaped the evolution of potent antiviral factors that suppress virus replication and protect the host from lethal infection. In the current study, we compared virus infection between reservoir host cells and related susceptible species. Infection of primary fibroblasts from the white-footed mouse (Peromyscus leucopus, a representative host) with a panel of vector-borne flaviviruses showed up to a 10,000-fold reduction in virus titer compared to control Mus musculus cells. Replication of vesicular stomatitis virus was equivalent in P. leucopus and M. musculus cells suggesting that restriction was flavivirus-specific. Step-wise comparison of the virus infection cycle revealed a significant block to viral RNA replication, but not virus entry, in P. leucopus cells. To understand the role of the type I interferon (IFN) response in virus restriction, we knocked down signal transducer and activator of transcription 1 (STAT1) or the type I IFN receptor (IFNAR1) by RNA interference. Loss of IFNAR1 or STAT1 significantly relieved the block in virus replication in P. leucopus cells. The major IFN antagonist encoded by TBFV, nonstructural protein 5, was functional in P. leucopus cells, thus ruling out ineffective viral antagonism of the host IFN response. Collectively, this work demonstrates that the IFN response of P. leucopus imparts a strong and virus-specific barrier to flavivirus replication. Future identification of the IFN-stimulated genes responsible for virus restriction specifically in P. leucopus will yield mechanistic insight into efficient control of virus replication and may inform the development of antiviral therapeutics.
-
Sun, Xiangjie; Belser, Jessica A.; Pulit-Penaloza, Joanna A.; Creager, Hannah M.; Guo, Zhu; Jefferson, Stacie N.; Liu, Feng; York, Ian A.; Stevens, James; Maines, Taronna R.; Jernigan, Daniel B.; Katz, Jacqueline M.; Levine, Min Z.; Tumpey, Terrence M.
2018-01-01
Avian influenza viruses, notably H5 subtype viruses, pose a continuous threat to public health due to their pandemic potential. In recent years, influenza virus H5 subtype split vaccines with novel oil-in-water emulsion based adjuvants (e.g. AS03, MF59) have been shown to be safe, immunogenic, and able to induce broad immune responses in clinical trials, providing strong scientific support for vaccine stockpiling. However, whether such vaccines can provide protection from infection with emerging, antigenically distinct clades of H5 viruses has not been adequately addressed. Here, we selected two AS03-adjuvanted H5N1 vaccines from the US national prepandemic influenza vaccine stockpile and assessed whether the 2004–05 vaccines could provide protection against a 2014 highly pathogenic avian influenza (HPAI) H5N2 virus (A/northern pintail/Washington/40964/2014), a clade 2.3.4.4 virus responsible for mass culling of poultry in North America. Ferrets received two doses of adjuvanted vaccine containing 7.5 μg of hemagglutinin (HA) from A/Vietnam/1203/2004 (clade 1) or A/Anhui/1/2005 (clade 2.3.4) virus either in a homologous or heterologous prime-boost vaccination regime. We found that both vaccination regimens elicited robust antibody responses against the 2004–05 vaccine viruses and could reduce virus-induced morbidity and viral replication in the lower respiratory tract upon heterologous challenge despite the low level of cross-reactive antibody titers to the challenge H5N2 virus. This study supports the value of existing stockpiled 2004–05 influenza H5N1 vaccines, combined with AS03-adjuvant for early use in the event of an emerging pandemic with H5N2-like clade 2.3.4.4 viruses. PMID:28554058
-
Viral Activation of Cellular Metabolism
Sanchez, Erica L.; Lagunoff, Michael
2015-01-01
To ensure optimal environments for their replication and spread, viruses have evolved to alter many host cell pathways. In the last decade, metabolomic studies have shown that eukaryotic viruses induce large-scale alterations in host cellular metabolism. Most viruses examined to date induce aerobic glycolysis also known as the Warburg effect. Many viruses tested also induce fatty acid synthesis as well as glutaminolysis. These modifications of carbon source utilization by infected cells can increase available energy for virus replication and virion production, provide specific cellular substrates for virus particles and create viral replication niches while increasing infected cell survival. Each virus species also likely requires unique metabolic changes for successful spread and recent research has identified additional virus-specific metabolic changes induced by many virus species. A better understanding of the metabolic alterations required for each virus may lead to novel therapeutic approaches through targeted inhibition of specific cellular metabolic pathways. PMID:25812764
-
Gauger, Phillip C; Vincent, Amy L; Loving, Crystal L; Lager, Kelly M; Janke, Bruce H; Kehrli, Marcus E; Roth, James A
2011-03-24
Influenza is an economically important respiratory disease affecting swine world-wide with potential zoonotic implications. Genetic reassortment and drift has resulted in genetically and antigenically distinct swine influenza viruses (SIVs). Consequently, prevention of SIV infection is challenging due to the increased rate of genetic change and a potential lack of cross-protection between vaccine strains and circulating novel isolates. This report describes a vaccine-heterologous challenge model in which pigs were administered an inactivated H1N2 vaccine with a human-like (δ-cluster) H1 six and three weeks before challenge with H1 homosubtypic, heterologous 2009 pandemic H1N1. At necropsy, macroscopic and microscopic pneumonia scores were significantly higher in the vaccinated and challenged (Vx/Ch) group compared to non-vaccinated and challenged (NVx/Ch) pigs. The Vx/Ch group also demonstrated enhanced clinical disease and a significantly elevated pro-inflammatory cytokine profile in bronchoalveolar lavage fluid compared to the NVx/Ch group. In contrast, viral shedding and replication were significantly higher in NVx/Ch pigs although all challenged pigs, including Vx/Ch pigs, were shedding virus in nasal secretions. Hemagglutination inhibition (HI) and serum neutralizing (SN) antibodies were detected to the priming antigen in the Vx/Ch pigs but no measurable cross-reacting HI or SN antibodies were detected to pandemic H1N1 (pH1N1). Overall, these results suggest that inactivated SIV vaccines may potentiate clinical signs, inflammation and pneumonia following challenge with divergent homosubtypic viruses that do not share cross-reacting HI or SN antibodies. Published by Elsevier Ltd.
-
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.
-
Sicurella, Mariaconcetta; Nicoli, Francesco; Gallerani, Eleonora; Volpi, Ilaria; Berto, Elena; Finessi, Valentina; Destro, Federica; Manservigi, Roberto; Cafaro, Aurelio; Ensoli, Barbara; Caputo, Antonella; Gavioli, Riccardo; Marconi, Peggy C
2014-01-01
Herpes simplex virus types 1 and 2 (HSV1 and HSV2) are common infectious agents in both industrialized and developing countries. They cause recurrent asymptomatic and/or symptomatic infections, and life-threatening diseases and death in newborns and immunocompromised patients. Current treatment for HSV relies on antiviral medications, which can halt the symptomatic diseases but cannot prevent the shedding that occurs in asymptomatic patients or, consequently, the spread of the viruses. Therefore, prevention rather than treatment of HSV infections has long been an area of intense research, but thus far effective anti-HSV vaccines still remain elusive. One of the key hurdles to overcome in anti-HSV vaccine development is the identification and effective use of strategies that promote the emergence of Th1-type immune responses against a wide range of epitopes involved in the control of viral replication. Since the HIV1 Tat protein has several immunomodulatory activities and increases CTL recognition of dominant and subdominant epitopes of heterologous antigens, we generated and assayed a recombinant attenuated replication-competent HSV1 vector containing the tat gene (HSV1-Tat). In this proof-of-concept study we show that immunization with this vector conferred protection in 100% of mice challenged intravaginally with a lethal dose of wild-type HSV1. We demonstrate that the presence of Tat within the recombinant virus increased and broadened Th1-like and CTL responses against HSV-derived T-cell epitopes and elicited in most immunized mice detectable IgG responses. In sharp contrast, a similarly attenuated HSV1 recombinant vector without Tat (HSV1-LacZ), induced low and different T cell responses, no measurable antibody responses and did not protect mice against the wild-type HSV1 challenge. These findings strongly suggest that recombinant HSV1 vectors expressing Tat merit further investigation for their potential to prevent and/or contain HSV1 infection and dissemination.
-
Sicurella, Mariaconcetta; Nicoli, Francesco; Gallerani, Eleonora; Volpi, Ilaria; Berto, Elena; Finessi, Valentina; Destro, Federica; Manservigi, Roberto; Cafaro, Aurelio; Ensoli, Barbara; Caputo, Antonella; Gavioli, Riccardo; Marconi, Peggy C.
2014-01-01
Herpes simplex virus types 1 and 2 (HSV1 and HSV2) are common infectious agents in both industrialized and developing countries. They cause recurrent asymptomatic and/or symptomatic infections, and life-threatening diseases and death in newborns and immunocompromised patients. Current treatment for HSV relies on antiviral medications, which can halt the symptomatic diseases but cannot prevent the shedding that occurs in asymptomatic patients or, consequently, the spread of the viruses. Therefore, prevention rather than treatment of HSV infections has long been an area of intense research, but thus far effective anti-HSV vaccines still remain elusive. One of the key hurdles to overcome in anti-HSV vaccine development is the identification and effective use of strategies that promote the emergence of Th1-type immune responses against a wide range of epitopes involved in the control of viral replication. Since the HIV1 Tat protein has several immunomodulatory activities and increases CTL recognition of dominant and subdominant epitopes of heterologous antigens, we generated and assayed a recombinant attenuated replication-competent HSV1 vector containing the tat gene (HSV1-Tat). In this proof-of-concept study we show that immunization with this vector conferred protection in 100% of mice challenged intravaginally with a lethal dose of wild-type HSV1. We demonstrate that the presence of Tat within the recombinant virus increased and broadened Th1-like and CTL responses against HSV-derived T-cell epitopes and elicited in most immunized mice detectable IgG responses. In sharp contrast, a similarly attenuated HSV1 recombinant vector without Tat (HSV1-LacZ), induced low and different T cell responses, no measurable antibody responses and did not protect mice against the wild-type HSV1 challenge. These findings strongly suggest that recombinant HSV1 vectors expressing Tat merit further investigation for their potential to prevent and/or contain HSV1 infection and dissemination. PMID:25033084
-
Debing, Yannick; Winton, James; Neyts, Johan; Dallmeier, Kai
2013-10-01
Hepatitis E virus (HEV) is one of the most important causes of acute hepatitis worldwide. Although most infections are self-limiting, mortality is particularly high in pregnant women. Chronic infections can occur in transplant and other immune-compromised patients. Successful treatment of chronic hepatitis E has been reported with ribavirin and pegylated interferon-alpha, however severe side effects were observed. We employed the cutthroat trout virus (CTV), a non-pathogenic fish virus with remarkable similarities to HEV, as a potential surrogate for HEV and established an antiviral assay against this virus using the Chinook salmon embryo (CHSE-214) cell line. Ribavirin and the respective trout interferon were found to efficiently inhibit CTV replication. Other known broad-spectrum inhibitors of RNA virus replication such as the nucleoside analog 2'-C-methylcytidine resulted only in a moderate antiviral activity. In its natural fish host, CTV levels largely fluctuate during the reproductive cycle with the virus detected mainly during spawning. We wondered whether this aspect of CTV infection may serve as a surrogate model for the peculiar pathogenesis of HEV in pregnant women. To that end the effect of three sex steroids on in vitro CTV replication was evaluated. Whereas progesterone resulted in marked inhibition of virus replication, testosterone and 17β-estradiol stimulated viral growth. Our data thus indicate that CTV may serve as a surrogate model for HEV, both for antiviral experiments and studies on the replication biology of the Hepeviridae. Copyright © 2013 Elsevier B.V. All rights reserved.
-
Molecular Basis of Latency in Pathogenic Human Viruses
NASA Astrophysics Data System (ADS)
Garcia-Blanco, Mariano A.; Cullen, Bryan R.
1991-11-01
Several human viruses are able to latently infect specific target cell populations in vivo. Analysis of the replication cycles of herpes simplex virus, Epstein-Barr virus, and human immunodeficiency virus suggests that the latent infections established by these human pathogens primarily result from a lack of host factors critical for the expression of viral early gene products. The subsequent activation of specific cellular transcription factors in response to extracellular stimuli can induce the expression of these viral regulatory proteins and lead to a burst of lytic viral replication. Latency in these eukaryotic viruses therefore contrasts with latency in bacteriophage, which is maintained primarily by the expression of virally encoded repressors of lytic replication.
-
Accessory genes confer a high replication rate to virulent feline immunodeficiency virus.
Troyer, Ryan M; Thompson, Jesse; Elder, John H; VandeWoude, Sue
2013-07-01
Feline immunodeficiency virus (FIV) is a lentivirus that causes AIDS in domestic cats, similar to human immunodeficiency virus (HIV)/AIDS in humans. The FIV accessory protein Vif abrogates the inhibition of infection by cat APOBEC3 restriction factors. FIV also encodes a multifunctional OrfA accessory protein that has characteristics similar to HIV Tat, Vpu, Vpr, and Nef. To examine the role of vif and orfA accessory genes in FIV replication and pathogenicity, we generated chimeras between two FIV molecular clones with divergent disease potentials: a highly pathogenic isolate that replicates rapidly in vitro and is associated with significant immunopathology in vivo, FIV-C36 (referred to here as high-virulence FIV [HV-FIV]), and a less-pathogenic strain, FIV-PPR (referred to here as low-virulence FIV [LV-FIV]). Using PCR-driven overlap extension, we produced viruses in which vif, orfA, or both genes from virulent HV-FIV replaced equivalent genes in LV-FIV. The generation of these chimeras is more straightforward in FIV than in primate lentiviruses, since FIV accessory gene open reading frames have very little overlap with other genes. All three chimeric viruses exhibited increased replication kinetics in vitro compared to the replication kinetics of LV-FIV. Chimeras containing HV-Vif or Vif/OrfA had replication rates equivalent to those of the virulent HV-FIV parental virus. Furthermore, small interfering RNA knockdown of feline APOBEC3 genes resulted in equalization of replication rates between LV-FIV and LV-FIV encoding HV-FIV Vif. These findings demonstrate that Vif-APOBEC interactions play a key role in controlling the replication and pathogenicity of this immunodeficiency-inducing virus in its native host species and that accessory genes act as mediators of lentiviral strain-specific virulence.
-
Xiang, Jinhua; McLinden, James H.; Rydze, Robert A.; Chang, Qing; Kaufman, Thomas M.; Klinzman, Donna; Stapleton, Jack T.
2013-01-01
Viral infections alter host cell homeostasis and this may lead to immune evasion and/or interfere with the replication of other microbes in coinfected hosts. Two flaviviruses are associated with a reduction in HIV replication or improved survival in HIV-infected people (dengue virus (DV) and GB virus type C (GBV-C)). GBV-C infection and expression of the GBV-C nonstructural protein 5A (NS5A) and the DV NS5 protein in CD4+ T cells inhibit HIV replication in vitro. To determine whether the inhibitory effect on HIV replication is conserved among other flaviviruses and to characterize mechanism(s) of HIV inhibition, the NS5 proteins of GBV-C, DV, hepatitis C virus, West Nile virus, and yellow fever virus (YFV; vaccine strain 17D) were expressed in CD4+ T cells. All NS5 proteins inhibited HIV replication. This correlated with decreased steady-state CD4 mRNA levels and reduced cell surface CD4 protein expression. Infection of CD4+ T cells and macrophages with YFV (17D vaccine strain) also inhibited HIV replication and decreased CD4 gene expression. In contrast, mumps virus was not inhibited by the expression of flavivirus NS5 protein or by YFV infection, and mumps infection did not alter CD4 mRNA or protein levels. In summary, CD4 gene expression is decreased by all human flavivirus NS5 proteins studied. CD4 regulation by flaviviruses may interfere with innate and adaptive immunity and contribute to in vitro HIV replication inhibition. Characterization of the mechanisms by which flaviviruses regulate CD4 expression may lead to novel therapeutic strategies for HIV and immunological diseases. PMID:19923460
-
Kamble, Nitin Machindra; Hajam, Irshad Ahmed; Lee, John Hwa
2017-03-01
Pre-stimulation of toll-like receptors (TLRs) by agonists has been shown to increase protection against influenza virus infection. In this study, we evaluated the protective response generated against influenza A/Puerto Rico/8/1934 (PR8; H1N1) virus by oral and nasal administration of live attenuated Salmonella enterica serovar Typhimurium, JOL911 strain, in mice. Oral and nasal inoculation of JOL911 significantly increased the mRNA copy number of TLR-2, TLR4 and TLR5, and downstream type I interferon (IFN) molecules, IFN-α and IFN-β, both in peripheral blood mononuclear cells (PBMCs) and in lung tissue. Similarly, the mRNA copy number of interferon-inducible genes (ISGs), Mx and ISG15, were significantly increased in both the orally and the nasally inoculated mice. Post PR8 virus lethal challenge, the nasal JOL911 and the PBS control group mice showed significant loss of body weight with 70% and 100% mortality, respectively, compared to only 30% mortality in the oral JOL911 group mice. Post sub-lethal challenge, the significant reduction in PR8 virus copy number in lung tissue was observed in oral [on day 4 and 6 post-challenge (dpc)] and nasal (on 4dpc) than the PBS control group mice. The lethal and sub-lethal challenge showed that the generated stimulated innate resistance (StIR) in JOL911 inoculated mice conferred resistance to acute and initial influenza infection but might not be sufficient to prevent the PR8 virus invasion and replication in the lung. Overall, the present study indicates that oral administration of attenuated S. Typhimurium can pre-stimulate multiple TLR pathways in mice to provide immediate early StIR against a lethal H1N1 virus challenge. Copyright © 2017 Elsevier B.V. All rights reserved.
-
Identification of a New Ribonucleoside Inhibitor of Ebola Virus Replication
Reynard, Olivier; Nguyen, Xuan-Nhi; Alazard-Dany, Nathalie; Barateau, Véronique; Cimarelli, Andrea; Volchkov, Viktor E.
2015-01-01
The current outbreak of Ebola virus (EBOV) in West Africa has claimed the lives of more than 15,000 people and highlights an urgent need for therapeutics capable of preventing virus replication. In this study we screened known nucleoside analogues for their ability to interfere with EBOV replication. Among them, the cytidine analogue β-d-N4-hydroxycytidine (NHC) demonstrated potent inhibitory activities against EBOV replication and spread at non-cytotoxic concentrations. Thus, NHC constitutes an interesting candidate for the development of a suitable drug treatment against EBOV. PMID:26633464
-
ERIC Educational Resources Information Center
Rajala, Judith B.
2004-01-01
A computer virus is a program--a piece of executable code--that has the unique ability to replicate. Like biological viruses, computer viruses can spread quickly and are often difficult to eradicate. They can attach themselves to just about any type of file, and are spread by replicating and being sent from one individual to another. Simply having…
-
Smith, Trevor R F; Schultheis, Katherine; Morrow, Matthew P; Kraynyak, Kimberly A; McCoy, Jay R; Yim, Kevin C; Muthumani, Karuppiah; Humeau, Laurent; Weiner, David B; Sardesai, Niranjan Y; Broderick, Kate E
2017-05-15
Respiratory syncytial virus (RSV) is a massive medical burden in infants, children and the elderly worldwide, and an effective, safe RSV vaccine remains an unmet need. Here we assess a novel vaccination strategy based on the intradermal delivery of a SynCon® DNA-based vaccine encoding engineered RSV-F antigen using a surface electroporation device (SEP) to target epidermal cells, in clinically relevant experimental models. We demonstrate the ability of this strategy to elicit robust immune responses. Importantly we demonstrate complete resistance to pulmonary infection at a single low dose of vaccine in the cotton rat RSV/A challenge model. In contrast to the formalin-inactivated RSV (FI-RSV) vaccine, there was no enhanced lung inflammation upon virus challenge after DNA vaccination. In summary the data presented outline the pre-clinical development of a highly efficacious, tolerable and safe non-replicating vaccine delivery strategy. Copyright © 2017. Published by Elsevier Ltd.
-
Hwang, Hye Suk; Kwon, Young-Man; Lee, Jong Seok; Yoo, Si-Eun; Lee, Yu-Na; Ko, Eun-Ju; Kim, Min-Chul; Cho, Min-Kyoung; Lee, Young-Tae; Jung, Yu-Jin; Lee, Ji-Yun; Li, Jian Dong; Kang, Sang-Moo
2014-01-01
This study demonstrates that immunization with non-replicating virus-like particle (FFG VLP) containing RSV F and G glycoproteins together with RSV F DNA induced T helper type 1 antibody responses to RSV F similar to live RSV infection. Upon RSV challenge 21 weeks after immunization, FFG VLP vaccination induced protection against RSV infection as shown by clearance of lung viral loads, and the absence of eosinophil infiltrates, and did not cause lung pathology. In contrast, formalin-inactivated RSV (FI-RSV) vaccination showed significant pulmonary eosinophilia, severe mucus production, and extensive histopathology resulting in a hallmark of pulmonary pathology. Substantial lung pathology was also observed in mice with RSV re-infections. High levels of systemic and local inflammatory cytokine-secreting cells were induced in mice with FI-RSV but not with FFG VLP immunization after RSV challenge. Therefore, the results provide evidence that recombinant RSV FFG VLP vaccine can confer long-term protection against RSV without causing lung pathology. PMID:25110201
-
Activation of DNA Damage Repair Pathways by Murine Polyomavirus
Heiser, Katie; Nicholas, Catherine; Garcea, Robert L.
2016-01-01
Nuclear replication of DNA viruses activates DNA damage repair (DDR) pathways, which are thought to detect and inhibit viral replication. However, many DNA viruses also depend on these pathways in order to optimally replicate their genomes. We investigated the relationship between murine polyomavirus (MuPyV) and components of DDR signaling pathways including CHK1, CHK2, H2AX, ATR, and DNAPK. We found that recruitment and retention of DDR proteins at viral replication centers was independent of H2AX, as well as the viral small and middle T-antigens. Additionally, infectious virus production required ATR kinase activity, but was independent of CHK1, CHK2, or DNAPK signaling. ATR inhibition did not reduce the total amount of viral DNA accumulated, but affected the amount of virus produced, indicating a defect in virus assembly. These results suggest that MuPyV may utilize a subset of DDR proteins or non-canonical DDR signaling pathways in order to efficiently replicate and assemble. PMID:27529739
-
A20 Deficiency in Lung Epithelial Cells Protects against Influenza A Virus Infection
Vereecke, Lars; Mc Guire, Conor; Sze, Mozes; Schuijs, Martijn J.; Willart, Monique; Itati Ibañez, Lorena; Hammad, Hamida; Lambrecht, Bart N.; Beyaert, Rudi; Saelens, Xavier; van Loo, Geert
2016-01-01
A20 negatively regulates multiple inflammatory signalling pathways. We here addressed the role of A20 in club cells (also known as Clara cells) of the bronchial epithelium in their response to influenza A virus infection. Club cells provide a niche for influenza virus replication, but little is known about the functions of these cells in antiviral immunity. Using airway epithelial cell-specific A20 knockout (A20AEC-KO) mice, we show that A20 in club cells critically controls innate immune responses upon TNF or double stranded RNA stimulation. Surprisingly, A20AEC-KO mice are better protected against influenza A virus challenge than their wild type littermates. This phenotype is not due to decreased viral replication. Instead host innate and adaptive immune responses and lung damage are reduced in A20AEC-KO mice. These attenuated responses correlate with a dampened cytotoxic T cell (CTL) response at later stages during infection, indicating that A20AEC-KO mice are better equipped to tolerate Influenza A virus infection. Expression of the chemokine CCL2 (also named MCP-1) is particularly suppressed in the lungs of A20AEC-KO mice during later stages of infection. When A20AEC-KO mice were treated with recombinant CCL2 the protective effect was abrogated demonstrating the crucial contribution of this chemokine to the protection of A20AEC-KO mice to Influenza A virus infection. Taken together, we propose a mechanism of action by which A20 expression in club cells controls inflammation and antiviral CTL responses in response to influenza virus infection. PMID:26815999
-
Influenza virus induces apoptosis via BAD-mediated mitochondrial dysregulation.
Tran, Anh T; Cortens, John P; Du, Qiujiang; Wilkins, John A; Coombs, Kevin M
2013-01-01
Influenza virus infection results in host cell death and major tissue damage. Specific components of the apoptotic pathway, a signaling cascade that ultimately leads to cell death, are implicated in promoting influenza virus replication. BAD is a cell death regulator that constitutes a critical control point in the intrinsic apoptosis pathway, which occurs through the dysregulation of mitochondrial outer membrane permeabilization and the subsequent activation of downstream apoptogenic factors. Here we report a novel proviral role for the proapoptotic protein BAD in influenza virus replication. We show that influenza virus-induced cytopathology and cell death are considerably inhibited in BAD knockdown cells and that both virus replication and viral protein production are dramatically reduced, which suggests that virus-induced apoptosis is BAD dependent. Our data showed that influenza viruses induced phosphorylation of BAD at residues S112 and S136 in a temporal manner. Viral infection also induced BAD cleavage, late in the viral life cycle, to a truncated form that is reportedly a more potent inducer of apoptosis. We further demonstrate that knockdown of BAD resulted in reduced cytochrome c release and suppression of the intrinsic apoptotic pathway during influenza virus replication, as seen by an inhibition of caspases-3, caspase-7, and procyclic acidic repetitive protein (PARP) cleavage. Our data indicate that influenza viruses carefully modulate the activation of the apoptotic pathway that is dependent on the regulatory function of BAD and that failure of apoptosis activation resulted in unproductive viral replication.
-
Influenza Virus Induces Apoptosis via BAD-Mediated Mitochondrial Dysregulation
Tran, Anh T.; Cortens, John P.; Du, Qiujiang; Wilkins, John A.
2013-01-01
Influenza virus infection results in host cell death and major tissue damage. Specific components of the apoptotic pathway, a signaling cascade that ultimately leads to cell death, are implicated in promoting influenza virus replication. BAD is a cell death regulator that constitutes a critical control point in the intrinsic apoptosis pathway, which occurs through the dysregulation of mitochondrial outer membrane permeabilization and the subsequent activation of downstream apoptogenic factors. Here we report a novel proviral role for the proapoptotic protein BAD in influenza virus replication. We show that influenza virus-induced cytopathology and cell death are considerably inhibited in BAD knockdown cells and that both virus replication and viral protein production are dramatically reduced, which suggests that virus-induced apoptosis is BAD dependent. Our data showed that influenza viruses induced phosphorylation of BAD at residues S112 and S136 in a temporal manner. Viral infection also induced BAD cleavage, late in the viral life cycle, to a truncated form that is reportedly a more potent inducer of apoptosis. We further demonstrate that knockdown of BAD resulted in reduced cytochrome c release and suppression of the intrinsic apoptotic pathway during influenza virus replication, as seen by an inhibition of caspases-3, caspase-7, and procyclic acidic repetitive protein (PARP) cleavage. Our data indicate that influenza viruses carefully modulate the activation of the apoptotic pathway that is dependent on the regulatory function of BAD and that failure of apoptosis activation resulted in unproductive viral replication. PMID:23135712
-
Ramey, Andy M.; Poulson, Rebecca L.; Gonzalez-Reiche, Ana S.; Perez, Daniel R.; Stalknecht, David E.; Brown, Justin D.
2014-01-01
Recent repeated isolation of H14 hemagglutinin subtype influenza A viruses (IAVs) in the New World waterfowl provides evidence to suggest that host and/or geographic ranges for viruses of this subtype may be expanding. In this study, we used genomic analyses to gain inference on the origin and evolution of H14 viruses in New World waterfowl and conducted an experimental challenge study in mallards (Anas platyrhynchos) to evaluate pathogenicity, viral replication, and transmissibility of a representative viral strain in a natural host species. Genomic characterization of H14 subtype IAVs isolated from New World waterfowl, including three isolates sequenced specifically for this study, revealed high nucleotide identity among individual gene segments (e.g. ≥95% shared identity among H14 HA gene segments). In contrast, lower shared identity was observed among internal gene segments. Furthermore, multiple neuraminidase subtypes were observed for H14 IAVs isolated in the New World. Gene segments of H14 viruses isolated after 2010 shared ancestral genetic lineages with IAVs isolated from wild birds throughout North America. Thus, genomic characterization provided evidence for viral evolution in New World waterfowl through genetic drift and genetic shift since purported introduction from Eurasia. In the challenge study, no clinical disease or lesions were observed among mallards experimentally inoculated with A/blue-winged teal/Texas/AI13-1028/2013(H14N5) or exposed via contact with infected birds. Titers of viral shedding for mallards challenged with the H14N5 IAV were highest at two days post-inoculation (DPI); however shedding was detected up to nine DPI using cloacal swabs. The distribution of viral antigen among mallards infected with H14N5 IAV was largely restricted to enterocytes lining the villi in the lower intestinal tract and in the epithelium of the bursa of Fabricius. Characterization of the infectivity of A/blue-winged teal/Texas/AI13-1028/2013(H14N5) in mallards provides support for similarities in viral replication and shedding as compared to previously described waterfowl-adapted, low pathogenic IAV strains in ducks.
-
Jorquera, Patricia A.; Choi, Youngjoo; Oakley, Katie E.; Powell, Thomas J.; Boyd, James G.; Palath, Naveen; Haynes, Lia M.; Anderson, Larry J.; Tripp, Ralph A.
2013-01-01
Nanoparticle vaccines were produced using layer-by-layer fabrication and incorporating respiratory syncytial virus (RSV) G protein polypeptides comprising the CX3C chemokine motif. BALB/c mice immunized with G protein nanoparticle vaccines produced a neutralizing antibody response that inhibited RSV replication in the lungs following RSV challenge. ELISPOT analysis showed that G nanoparticle vaccinated mice had increased levels of RSV G protein-specific IL-4 and IFN-γ secreting cells compared to controls following RSV challenge. Remarkably, RSV challenge of G protein nanoparticle vaccinated mice resulted in increased RSV M2-specific IL-4 and IFN-γ secreting T cells, and increased M2-specific H-2Kd-tetramer positive CD8+ T cells in the lungs compared to controls. Cell type analysis showed vaccination was not associated with increased pulmonary eosinophilia following RSV challenge. These results demonstrate that vaccination of mice with the RSV G protein nanoparticle vaccines induces a potent neutralizing antibody response, increased G protein- and M2- specific T cell responses, and a reduction in RSV disease pathogenesis. PMID:24040360
-
O'Donnell, Christopher D.; Wright, Amber; Vogel, Leatrice N.; Wei, Chih-Jen; Nabel, Gary J.
2012-01-01
Compared to seasonal influenza viruses, the 2009 pandemic H1N1 (pH1N1) virus caused greater morbidity and mortality in children and young adults. People over 60 years of age showed a higher prevalence of cross-reactive pH1N1 antibodies, suggesting that they were previously exposed to an influenza virus or vaccine that was antigenically related to the pH1N1 virus. To define the basis for this cross-reactivity, ferrets were infected with H1N1 viruses of variable antigenic distance that circulated during different decades from the 1930s (Alaska/35), 1940s (Fort Monmouth/47), 1950s (Fort Warren/50), and 1990s (New Caledonia/99) and challenged with 2009 pH1N1 virus 6 weeks later. Ferrets primed with the homologous CA/09 or New Jersey/76 (NJ/76) virus served as a positive control, while the negative control was an influenza B virus that should not cross-protect against influenza A virus infection. Significant protection against challenge virus replication in the respiratory tract was observed in ferrets primed with AK/35, FM/47, and NJ/76; FW/50-primed ferrets showed reduced protection, and NC/99-primed ferrets were not protected. The hemagglutinins (HAs) of AK/35, FM/47, and FW/50 differ in the presence of glycosylation sites. We found that the loss of protective efficacy observed with FW/50 was associated with the presence of a specific glycosylation site. Our results suggest that changes in the HA occurred between 1947 and 1950, such that prior infection could no longer protect against 2009 pH1N1 infection. This provides a mechanistic understanding of the nature of serological cross-protection observed in people over 60 years of age during the 2009 H1N1 pandemic. PMID:22674976
-
O'Donnell, Christopher D; Wright, Amber; Vogel, Leatrice N; Wei, Chih-Jen; Nabel, Gary J; Subbarao, Kanta
2012-08-01
Compared to seasonal influenza viruses, the 2009 pandemic H1N1 (pH1N1) virus caused greater morbidity and mortality in children and young adults. People over 60 years of age showed a higher prevalence of cross-reactive pH1N1 antibodies, suggesting that they were previously exposed to an influenza virus or vaccine that was antigenically related to the pH1N1 virus. To define the basis for this cross-reactivity, ferrets were infected with H1N1 viruses of variable antigenic distance that circulated during different decades from the 1930s (Alaska/35), 1940s (Fort Monmouth/47), 1950s (Fort Warren/50), and 1990s (New Caledonia/99) and challenged with 2009 pH1N1 virus 6 weeks later. Ferrets primed with the homologous CA/09 or New Jersey/76 (NJ/76) virus served as a positive control, while the negative control was an influenza B virus that should not cross-protect against influenza A virus infection. Significant protection against challenge virus replication in the respiratory tract was observed in ferrets primed with AK/35, FM/47, and NJ/76; FW/50-primed ferrets showed reduced protection, and NC/99-primed ferrets were not protected. The hemagglutinins (HAs) of AK/35, FM/47, and FW/50 differ in the presence of glycosylation sites. We found that the loss of protective efficacy observed with FW/50 was associated with the presence of a specific glycosylation site. Our results suggest that changes in the HA occurred between 1947 and 1950, such that prior infection could no longer protect against 2009 pH1N1 infection. This provides a mechanistic understanding of the nature of serological cross-protection observed in people over 60 years of age during the 2009 H1N1 pandemic.
-
Kapczynski, Darrell R; Pantin-Jackwood, Mary; Guzman, Sofia G; Ricardez, Yadira; Spackman, Erica; Bertran, Kateri; Suarez, David L; Swayne, David E
2013-08-01
In June of 2012, an H7N3 highly pathogenic avian influenza (HPAI) virus was identified as the cause of a severe disease outbreak in commercial laying chicken farms in Mexico. The purpose of this study was to characterize the Mexican 2012 H7N3 HPAI virus (A/chicken/Jalisco/CPA1/2012) and determine the protection against the virus conferred by different H7 inactivated vaccines in chickens. Both adult and young chickens intranasally inoculated with the virus became infected and died at between 2 and 4 days postinoculation (p.i.). High virus titers and viral replication in many tissues were demonstrated at 2 days p.i. in infected birds. The virus from Jalisco, Mexico, had high sequence similarity of greater than 97% to the sequences of wild bird viruses from North America in all eight gene segments. The hemagglutinin gene of the virus contained a 24-nucleotide insert at the hemagglutinin cleavage site which had 100% sequence identity to chicken 28S rRNA, suggesting that the insert was the result of nonhomologous recombination with the host genome. For vaccine protection studies, both U.S. H7 low-pathogenic avian influenza (LPAI) viruses and a 2006 Mexican H7 LPAI virus were tested as antigens in experimental oil emulsion vaccines and injected into chickens 3 weeks prior to challenge. All H7 vaccines tested provided ≥90% protection against clinical disease after challenge and decreased the number of birds shedding virus and the titers of virus shed. This study demonstrates the pathological consequences of the infection of chickens with the 2012 Mexican lineage H7N3 HPAI virus and provides support for effective programs of vaccination against this virus in poultry.
-
Relative resistance of HIV-1 founder viruses to control by interferon-alpha
2013-01-01
Background Following mucosal human immunodeficiency virus type 1 (HIV-1) transmission, type 1 interferons (IFNs) are rapidly induced at sites of initial virus replication in the mucosa and draining lymph nodes. However, the role played by IFN-stimulated antiviral activity in restricting HIV-1 replication during the initial stages of infection is not clear. We hypothesized that if type 1 IFNs exert selective pressure on HIV-1 replication in the earliest stages of infection, the founder viruses that succeed in establishing systemic infection would be more IFN-resistant than viruses replicating during chronic infection, when type 1 IFNs are produced at much lower levels. To address this hypothesis, the relative resistance of virus isolates derived from HIV-1-infected individuals during acute and chronic infection to control by type 1 IFNs was analysed. Results The replication of plasma virus isolates generated from subjects acutely infected with HIV-1 and molecularly cloned founder HIV-1 strains could be reduced but not fully suppressed by type 1 IFNs in vitro. The mean IC50 value for IFNα2 (22 U/ml) was lower than that for IFNβ (346 U/ml), although at maximally-inhibitory concentrations both IFN subtypes inhibited virus replication to similar extents. Individual virus isolates exhibited differential susceptibility to inhibition by IFNα2 and IFNβ, likely reflecting variation in resistance to differentially up-regulated IFN-stimulated genes. Virus isolates from subjects acutely infected with HIV-1 were significantly more resistant to in vitro control by IFNα than virus isolates generated from the same individuals during chronic, asymptomatic infection. Viral IFN resistance declined rapidly after the acute phase of infection: in five subjects, viruses derived from six-month consensus molecular clones were significantly more sensitive to the antiviral effects of IFNs than the corresponding founder viruses. Conclusions The establishment of systemic HIV-1 infection by relatively IFNα-resistant founder viruses lends strong support to the hypothesis that IFNα plays an important role in the control of HIV-1 replication during the earliest stages of infection, prior to systemic viral spread. These findings suggest that it may be possible to harness the antiviral activity of type 1 IFNs in prophylactic and potentially also therapeutic strategies to combat HIV-1 infection. PMID:24299076
-
Avian Influenza H7N9/13 and H7N7/13: a Comparative Virulence Study in Chickens, Pigeons, and Ferrets
Kalthoff, Donata; Bogs, Jessica; Grund, Christian; Tauscher, Kerstin; Teifke, Jens P.; Starick, Elke; Harder, Timm
2014-01-01
ABSTRACT Human influenza cases caused by a novel avian H7N9 virus in China emphasize the zoonotic potential of that subtype. We compared the infectivity and pathogenicity of the novel H7N9 virus with those of a recent European avian H7N7 strain in chickens, pigeons, and ferrets. Neither virus induced signs of disease despite substantial replication in inoculated chickens and rapid transmission to contact chickens. Evidence of the replication of both viruses in pigeons, albeit at lower levels of RNA excretion, was also detected. No clear-cut differences between the two H7 isolates emerged regarding replication and antibody development in avian hosts. In ferrets, in contrast, greater replication of the avian H7N9 virus than of the H7N7 strain was observed with significant differences in viral presence, e.g., in nasal wash, lung, and cerebellum samples. Importantly, both viruses showed the potential to spread to the mammal brain. We conclude that efficient asymptomatic viral replication and shedding, as shown in chickens, facilitate the spread of H7 viruses that may harbor zoonotic potential. Biosafety measures are required for the handling of poultry infected with avian influenza viruses of the H7 subtype, independently of their pathogenicity for gallinaceous poultry. IMPORTANCE This study is important to the field since it provides data about the behavior of the novel H7N9 avian influenza virus in chickens, pigeons, and ferrets in comparison with that of a recent low-pathogenicity H7N7 strain isolated from poultry. We clearly show that chickens, but not pigeons, are highly permissive hosts of both H7 viruses, allowing high-titer replication and virus shedding without any relevant clinical signs. In the ferret model, the potential of both viruses to infect mammals could be demonstrated, including infection of the brain. However, the replication efficiency of the H7N9 virus in ferrets was higher than that of the H7N7 strain. In conclusion, valuable data for the risk analysis of low-pathogenicity avian influenza viruses of the H7 subtype are provided that could also be used for the risk assessment of zoonotic potentials and necessary biosafety measures. PMID:24899194
-
Kalthoff, Donata; Bogs, Jessica; Grund, Christian; Tauscher, Kerstin; Teifke, Jens P; Starick, Elke; Harder, Timm; Beer, Martin
2014-08-01
Human influenza cases caused by a novel avian H7N9 virus in China emphasize the zoonotic potential of that subtype. We compared the infectivity and pathogenicity of the novel H7N9 virus with those of a recent European avian H7N7 strain in chickens, pigeons, and ferrets. Neither virus induced signs of disease despite substantial replication in inoculated chickens and rapid transmission to contact chickens. Evidence of the replication of both viruses in pigeons, albeit at lower levels of RNA excretion, was also detected. No clear-cut differences between the two H7 isolates emerged regarding replication and antibody development in avian hosts. In ferrets, in contrast, greater replication of the avian H7N9 virus than of the H7N7 strain was observed with significant differences in viral presence, e.g., in nasal wash, lung, and cerebellum samples. Importantly, both viruses showed the potential to spread to the mammal brain. We conclude that efficient asymptomatic viral replication and shedding, as shown in chickens, facilitate the spread of H7 viruses that may harbor zoonotic potential. Biosafety measures are required for the handling of poultry infected with avian influenza viruses of the H7 subtype, independently of their pathogenicity for gallinaceous poultry. This study is important to the field since it provides data about the behavior of the novel H7N9 avian influenza virus in chickens, pigeons, and ferrets in comparison with that of a recent low-pathogenicity H7N7 strain isolated from poultry. We clearly show that chickens, but not pigeons, are highly permissive hosts of both H7 viruses, allowing high-titer replication and virus shedding without any relevant clinical signs. In the ferret model, the potential of both viruses to infect mammals could be demonstrated, including infection of the brain. However, the replication efficiency of the H7N9 virus in ferrets was higher than that of the H7N7 strain. In conclusion, valuable data for the risk analysis of low-pathogenicity avian influenza viruses of the H7 subtype are provided that could also be used for the risk assessment of zoonotic potentials and necessary biosafety measures. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
-
p53-Mediated Cellular Response to DNA Damage in Cells with Replicative Hepatitis B Virus
NASA Astrophysics Data System (ADS)
Puisieux, Alain; Ji, Jingwei; Guillot, Celine; Legros, Yann; Soussi, Thierry; Isselbacher, Kurt; Ozturk, Mehmet
1995-02-01
Wild-type p53 acts as a tumor suppressor gene by protecting cells from deleterious effects of genotoxic agents through the induction of a G_1/S arrest or apoptosis as a response to DNA damage. Transforming proteins of several oncogenic DNA viruses inactivate tumor suppressor activity of p53 by blocking this cellular response. To test whether hepatitis B virus displays a similar effect, we studied the p53-mediated cellular response to DNA damage in 2215 hepatoma cells with replicative hepatitis B virus. We demonstrate that hepatitis B virus replication does not interfere with known cellular functions of p53 protein.
-
Hepatitis D virus replication is sensed by MDA5 and induces IFN-β/λ responses in hepatocytes.
Zhang, Zhenfeng; Filzmayer, Christina; Ni, Yi; Sültmann, Holger; Mutz, Pascal; Hiet, Marie-Sophie; Vondran, Florian W R; Bartenschlager, Ralf; Urban, Stephan
2018-07-01
Hepatitis B virus (HBV) and D virus (HDV) co-infections cause the most severe form of viral hepatitis. HDV induces an innate immune response, but it is unknown how the host cell senses HDV and if this defense affects HDV replication. We aim to characterize interferon (IFN) activation by HDV, identify the responsible sensor and evaluate the effect of IFN on HDV replication. HDV and HBV susceptible hepatoma cell lines and primary human hepatocytes (PHH) were used for infection studies. Viral markers and cellular gene expression were analyzed at different time points after infection. Pattern recognition receptors (PRRs) required for HDV-mediated IFN activation and the impact on HDV replication were studied using stable knock-down or overexpression of the PRRs. Microarray analysis revealed that HDV but not HBV infection activated a broad range of interferon stimulated genes (ISGs) in HepG2 NTCP cells. HDV strongly activated IFN-β and IFN-λ in cell lines and PHH. HDV induced IFN levels remained unaltered upon RIG-I (DDX58) or TLR3 knock-down, but were almost completely abolished upon MDA5 (IFIH1) depletion. Conversely, overexpression of MDA5 but not RIG-I and TLR3 in HuH7.5 NTCP cells partially restored ISG induction. During long-term infection, IFN levels gradually diminished in both HepG2 NTCP and HepaRG NTCP cell lines. MDA5 depletion had little effect on HDV replication despite dampening HDV-induced IFN response. Moreover, treatment with type I or type III IFNs did not abolish HDV replication. Active replication of HDV induces an IFN-β/λ response, which is predominantly mediated by MDA5. This IFN response and exogenous IFN treatment have only a moderate effect on HDV replication in vitro indicating the adaption of HDV replication to an IFN-activated state. In contrast to hepatitis B virus, infection with hepatitis D virus induces a strong IFN-β/λ response in innate immune competent cell lines. MDA5 is the key sensor for the recognition of hepatitis D virus replicative intermediates. An IFN-activated state did not prevent hepatitis D virus replication in vitro, indicating that hepatitis D virus is resistant to self-induced innate immune responses and therapeutic IFN treatment. Copyright © 2018 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
-
Capella, Cristina; Beltejar, Michael-John; Brown, Caitlin; Fong, Vincent; Daddacha, Waaqo; Kim, Baek
2012-01-01
Mutations that reduce the efficiency of deoxynucleoside (dN) triphosphate (dNTP) substrate utilization by the HIV-1 DNA polymerase prevent viral replication in resting cells, which contain low dNTP concentrations, but not in rapidly dividing cells such as cancer cells, which contain high levels of dNTPs. We therefore tested whether mutations in regions of the adenovirus type 5 (Ad5) DNA polymerase that interact with the dNTP substrate or DNA template could alter virus replication. The majority of the mutations created, including conservative substitutions, were incompatible with virus replication. Five replication-competent mutants were recovered from 293 cells, but four of these mutants failed to replicate in A549 lung carcinoma cells and Wi38 normal lung cells. Purified polymerase proteins from these viruses exhibited only a 2- to 4-fold reduction in their dNTP utilization efficiency but nonetheless could not be rescued, even when intracellular dNTP concentrations were artificially raised by the addition of exogenous dNs to virus-infected A549 cells. The fifth mutation (I664V) reduced biochemical dNTP utilization by the viral polymerase by 2.5-fold. The corresponding virus replicated to wild-type levels in three different cancer cell lines but was significantly impaired in all normal cell lines in which it was tested. Efficient replication and virus-mediated cell killing were rescued by the addition of exogenous dNs to normal lung fibroblasts (MRC5 cells), confirming the dNTP-dependent nature of the polymerase defect. Collectively, these data provide proof-of-concept support for the notion that conditionally replicating, tumor-selective adenovirus vectors can be created by modifying the efficiency with which the viral DNA polymerase utilizes dNTP substrates. PMID:22811532
-
Wang, Kening; Goodman, Kyle N; Li, Daniel Y; Raffeld, Mark; Chavez, Mayra; Cohen, Jeffrey I
2016-01-01
A recent phase 3 trial with soluble herpes simplex virus 2 (HSV-2) glycoprotein D (gD2t) in adjuvant failed to show protection against genital herpes. We postulated that live attenuated HSV-2 would provide more HSV antigens for induction of virus-specific antibodies and cellular immunity than would gD2t. We previously reported an HSV-2 mutant, HSV2-gD27, in which the nectin-1 binding domain of gD2 is altered so that the virus is impaired for infecting neural cells, but not epithelial cells, in vitro and is impaired for infecting dorsal root ganglia in mice (K. Wang, J. D. Kappel, C. Canders, W. F. Davila, D. Sayre, M. Chavez, L. Pesnicak, and J. I. Cohen, J Virol 86:12891-12902, 2012, doi:10.1128/JVI.01055-12). Here we report that the mutations in HSV2-gD27 were stable when the virus was passaged in cell culture and during acute infection of mice. HSV2-gD27 was attenuated in mice when it was inoculated onto the cornea, intramuscularly (i.m.), intravaginally, and intracranially. Vaccination of mice i.m. with HSV2-gD27 provided better inhibition of challenge virus replication in the vagina than when the virus was used to vaccinate mice intranasally or subcutaneously. Comparison of i.m. vaccinations with HSV2-gD27 versus gD2t in adjuvant showed that HSV2-gD27 induced larger reductions of challenge virus replication in the vagina and reduced latent viral loads in dorsal root ganglia but induced lower serum neutralizing antibody titers than those obtained with gD2t in adjuvant. Taken together, our data indicate that a live attenuated HSV-2 vaccine impaired for infection of neurons provides better protection from vaginal challenge with HSV-2 than that obtained with a subunit vaccine, despite inducing lower titers of HSV-2 neutralizing antibodies in the serum. Genital herpes simplex is one of the most prevalent sexually transmitted diseases. Though HSV-2 disease is usually mild, it can be life threatening in neonates and immunocompromised persons. In addition, genital herpes increases the frequency of HIV infection and transmission. HSV-2 maintains a latent infection in sensory neurons and cannot be cleared with antiviral drugs. The virus frequently reactivates, resulting in virus shedding in the genital area, which serves as a source for transmission. A prophylactic vaccine is needed to prevent disease and to control the spread of the virus. Previous human trials of subunit vaccines have been unsuccessful. Here we report the results of vaccinating mice with a new type of live attenuated HSV-2 vaccine that is impaired for infection of neurons and provides better protection of mice than that obtained with a subunit vaccine. The strategy of altering the cell tropism of a virus is a new approach for a live attenuated vaccine. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
-
Hiremath, Jagadish; Kang, Kyung-il; Xia, Ming; Elaish, Mohamed; Binjawadagi, Basavaraj; Ouyang, Kang; Dhakal, Santosh; Arcos, Jesus; Torrelles, Jordi B; Jiang, X; Lee, Chang Won; Renukaradhya, Gourapura J
2016-01-01
Pigs are believed to be one of the important sources of emerging human and swine influenza viruses (SwIV). Influenza virus conserved peptides have the potential to elicit cross-protective immune response, but without the help of potent adjuvant and delivery system they are poorly immunogenic. Biodegradable polylactic-co-glycolic acid (PLGA) nanoparticle (PLGA-NP) based vaccine delivery system enhances cross-presentation of antigens by the professional antigen presenting cells. In this study, Norovirus P particle containing SwIV M2e (extracellular domain of the matrix protein 2) chimera and highly conserved two each of H1N1 peptides of pandemic 2009 and classical human influenza viruses were entrapped in PLGA-NPs. Influenza antibody-free pigs were vaccinated with PLGA-NPs peptides cocktail vaccine twice with or without an adjuvant, Mycobacterium vaccae whole cell lysate, intranasally as mist. Vaccinated pigs were challenged with a virulent heterologous zoonotic SwIV H1N1, and one week later euthanized and the lung samples were analyzed for the specific immune response and viral load. Clinically, pigs vaccinated with PLGA-NP peptides vaccine had no fever and flu symptoms, and the replicating challenged SwIV was undetectable in the bronchoalveolar lavage fluid. Immunologically, PLGA-NP peptides vaccination (without adjuvant) significantly increased the frequency of antigen-specific IFNγ secreting CD4 and CD8 T cells response in the lung lymphocytes, despite not boosting the antibody response both at pre- and post-challenge. In summary, our data indicated that nanoparticle-mediated delivery of conserved H1N1 influenza peptides induced the virus specific T cell response in the lungs and reduced the challenged heterologous virus load in the airways of pigs.
-
Elderfield, Ruth A; Parker, Lauren; Stilwell, Peter; Roberts, Kim L; Schepelmann, Silke; Barclay, Wendy S
2015-08-01
Ferrets have become the model animal of choice for influenza pathology and transmission experiments as they are permissive and susceptible to human influenza A viruses. However, inoculation of ferrets with mumps virus (MuV) did not lead to successful infections. We evaluated the use of highly differentiated ferret tracheal epithelium cell cultures, FTE, for predicting the potential of ferrets to support respiratory viral infections. FTE cultures supported productive replication of human influenza A and B viruses but not of MuV, whereas analogous cells generated from human airways supported replication of all three viruses. We propose that in vitro strategies using these cultures might serve as a method of triaging viruses and potentially reducing the use of ferrets in viral studies.
-
Sublethal effects of iridovirus disease in a mosquito.
Marina, Carlos F; Arredondo-Jiménez, Juan I; Castillo, Alfredo; Williams, Trevor
1999-05-01
Recognition of the importance of debilitating effects of insect virus diseases is currently growing. Commonly observed effects of sublethal infection at the individual level include extended development times, reduced pupal and adult weights, and lowered fecundity. However, for the most part, sublethal infections are assumed to be present in survivors of an inoculum challenge, rather than demonstrated to be present by microscopy or molecular techniques. Invertebrate iridescent viruses are dsDNA viruses capable of causing disease with symptoms obvious to the naked eye, a "patent" infection, that is lethal. Furthermore, inapparent "covert" infections may occur that are non-lethal and which can only be detected using bioassay or molecular techniques. In this study, replication of Invertebrate iridescent virus 6 in Aedes aegypti larvae was demonstrated in the absence of patent disease. A sensitive insect bioassay (using Galleria mellonella) allowed the detection of covert infections, which were more common than patent infections. A concentration-response relationship was detected for the incidence of patent infections. Covert infections were up to 2 orders of magnitude commoner than patent infections, but the prevalence of covert infections did not appear to be related to virus inoculum concentration. Exposure of larvae to virus inoculum resulted in extended juvenile development times. A reduction in the mean and an increase in the variability of fecundity and adult progeny production was observed in females exposed to an inoculum challenge, although formal analysis was not possible. Males appeared capable of passing virus to uninfected females during the mating process. Covertly infected females were smaller and had shorter lifespans than control or virus-challenged females. A conservative estimate for the reduction in the net reproductive rate (R 0 ) of such insects was calculated at slightly more than 20% relative to controls.
-
Akhtar, T.; Ara, G.; Ali, N.; ud Din Mufti, F.; Imran Khan, M.
2016-01-01
Avian influenza (AI) is a highly contagious disease causing significant economic losses worldwide. The aim of this study is to evaluate the effect of mannan-oligosaccharide (MOS) on tracheal and cloacal virus shedding in AI challenged broilers and contamination of environment with H9N2. A total of 300 1-day-old-broiler chicks were randomly divided into 3 groups (A, B and C) and supplemented 0.2, 0.5 and 0.0% MOS, respectively in NRC recommended diet for 36 days. On day 21 the groups were further split into two sub groups A+ve, A-ve, B+ve, B-ve, C+ve and C-ve with 5 replicates each. The positive groups were shifted to remote sheds and were challenged intranasally with 0.1 ml of reference virus (AIV; Pk-UDL/01/08 H9N2) with EID50 = 10-6.66. Treatment reduces (P<0.05) cloacal virus shedding from day 24 to 26 and 28 to 32. Tracheal virus shedding was lower (P<0.05) on days 25-26 and 28-30 in treatment groups. Day 27 showed highest (P>0.05) virus shedding in all groups. However the reduction of viral shedding is faster in treatment groups and showed no virus shedding on day 32. Maternal antibody titer against AI showed a declining pattern but MOS influenced (P<0.05) the titer in treated groups. Hence the use of MOS may constitute a novel and effective plausible alternative that reduces the spread of disease by decreasing virus shedding and contamination of environment from AIV (H9N2) infection in poultry. PMID:28224012
-
NASA Astrophysics Data System (ADS)
Vahey, Michael
Despite relevance to human health, the mechanisms of enveloped virus assembly remain largely mysterious. This is particularly true of influenza A virus (IAV), which (unlike viral capsids with stereotyped shape and composition) forms heterogeneous particles whose assembly cannot be described in terms of equilibrium thermodynamics. Although the ability to assemble into particles with diverse size and composition could have important implications for infectivity, understanding how virion-to-virion differences arise and how they ultimately influence virus replication has proven challenging due to the lack of available tools for studying the assembly process. To address this challenge and establish a dynamic picture of how IAV assembles, we have developed virus strains that harbor small, non-disruptive fluorescent tags on each of the virus's five major structural proteins. Using these multispectral strains, we are able to quantify the protein composition and dynamics of virions as they assemble in live infected cells - measurements that have been previously inaccessible, and which reveal subpopulations of virus that favor either the binding or destruction of host receptors. The occupancy of these different subpopulations is malleable, shifting in response to environmental stimuli, including antiviral drugs that block receptor-destruction. In complex environments like the human respiratory tract, this phenotypic diversity could act as an evolutionary hedge. We acknowledge the Burroughs Wellcome Fund and NIH NIGMS for supporting this work.
-
Yuan, Tiangang; Wang, Haiwei; Li, Chen; Yang, Decheng; Zhou, Guohui; Yu, Li
2017-12-01
The foot-and-mouth disease virus (FMDV) nonstructural protein 3A plays an important role in viral replication, virulence, and host range. It has been shown that deletions of 10 or 19-20 amino acids in the C-terminal half of 3A attenuate serotype O and C FMDVs, which replicate poorly in bovine cells but normally in porcine-derived cells, and the C-terminal half of 3A is not essential for serotype Asia1 FMDV replication in BHK-21 cells. In this study, we constructed a 3A deletion FMDV mutant based on a serotype O FMDV, the wild-type virus O/YS/CHA/05, with a 60-amino acid deletion in the 3A protein sequence, between residues 84 and 143. The rescued virus O/YS/CHA/05-Δ3A exhibited slower growth kinetics and formed smaller plaques compared to O/YS/CHA/05 in both BHK-21 and IBRS-2 cells, indicating that the 60-amino acid deletion in the 3A protein impaired FMDV replication. After 14 passages in BHK-21 cells, the replication capacity of the passaged virus O/YS/CHA/05-Δ3A-P14 returned to a level similar to the wild-type virus, suggesting that amino acid substitutions responsible for the enhanced replication capacity occurred in the genome of O/YS/CHA/05-Δ3A-P14. By sequence analysis, two amino acid substitutions, P153L in VP1 and T135I in 2C, were found in the O/YS/CHA/05-Δ3A-P14 genome compared to the O/YS/CHA/05-Δ3A genome. Subsequently, the amino acid substitutions VP1 P153L and 2C T135I were separately introduced into O/YS/CHA/05-Δ3A to rescue mutant viruses for examining their growth kinetics. Results showed that the 2C T135I instead of the VP1 P153L enhanced the virus replication capacity. The 2C T135I substitution also improved the replication of the wild-type virus, indicating that the effect of 2C T135I substitution on FMDV replication is not associated with the 3A deletion. Furthermore, our results showed that the T135I substitution in the nonstructural protein 2C enhanced O/YS/CHA/05 replication through promoting viral RNA synthesis.
-
The cytoprotective enzyme heme oxygenase-1 suppresses Ebola virus replication.
Hill-Batorski, Lindsay; Halfmann, Peter; Neumann, Gabriele; Kawaoka, Yoshihiro
2013-12-01
Ebola virus (EBOV) is the causative agent of a severe hemorrhagic fever in humans with reported case fatality rates as high as 90%. There are currently no licensed vaccines or antiviral therapeutics to combat EBOV infections. Heme oxygenase-1 (HO-1), an enzyme that catalyzes the rate-limiting step in heme degradation, has antioxidative properties and protects cells from various stresses. Activated HO-1 was recently shown to have antiviral activity, potently inhibiting the replication of viruses such as hepatitis C virus and human immunodeficiency virus. However, the effect of HO-1 activation on EBOV replication remains unknown. To determine whether the upregulation of HO-1 attenuates EBOV replication, we treated cells with cobalt protoporphyrin (CoPP), a selective HO-1 inducer, and assessed its effects on EBOV replication. We found that CoPP treatment, pre- and postinfection, significantly suppressed EBOV replication in a manner dependent upon HO-1 upregulation and activity. In addition, stable overexpression of HO-1 significantly attenuated EBOV growth. Although the exact mechanism behind the antiviral properties of HO-1 remains to be elucidated, our data show that HO-1 upregulation does not attenuate EBOV entry or budding but specifically targets EBOV transcription/replication. Therefore, modulation of the cellular enzyme HO-1 may represent a novel therapeutic strategy against EBOV infection.
-
Immune and Genetic Correlates of Vaccine Protection Against Mucosal Infection by SIV in Monkeys
Letvin, Norman L.; Rao, Srinivas S.; Montefiori, David C.; Seaman, Michael S.; Sun, Yue; Lim, So-Yon; Yeh, Wendy W.; Asmal, Mohammed; Gelman, Rebecca S.; Shen, Ling; Whitney, James B.; Seoighe, Cathal; Lacerda, Miguel; Keating, Sheila; Norris, Philip J.; Hudgens, Michael G.; Gilbert, Peter B.; Buzby, Adam P.; Mach, Linh V.; Zhang, Jinrong; Balachandran, Harikrishnan; Shaw, George M.; Schmidt, Stephen D.; Todd, John-Paul; Dodson, Alan; Mascola, John R.; Nabel, Gary J.
2013-01-01
The RV144 vaccine trial in Thailand demonstrated that an HIV vaccine could prevent infection in humans and highlights the importance of understanding protective immunity against HIV. We used a nonhuman primate model to define immune and genetic mechanisms of protection against mucosal infection by the simian immunodeficiency virus (SIV). A plasmid DNA prime/recombinant adenovirus serotype 5 (rAd5) boost vaccine regimen was evaluated for its ability to protect monkeys from infection by SIVmac251 or SIVsmE660 isolates after repeat intrarectal challenges. Although this prime-boost vaccine regimen failed to protect against SIVmac251 infection, 50% of vaccinated monkeys were protected from infection with SIVsmE660. Among SIVsmE660-infected animals, there was an about one-log reduction in peak plasma virus RNA in monkeys expressing the major histocompatibility complex class I allele Mamu-A*01, implicating cytotoxic T lymphocytes in the control of SIV replication once infection is established. Among Mamu-A*01–negative monkeys challenged with SIVsmE660, no CD8+ T cell response or innate immune response was associated with protection against virus acquisition. However, low levels of neutralizing antibodies and an envelope-specific CD4+ T cell response were associated with vaccine protection in these monkeys. Moreover, monkeys that expressed two TRIM5 alleles that restrict SIV replication were more likely to be protected from infection than monkeys that expressed at least one permissive TRIM5 allele. This study begins to elucidate the mechanism of vaccine protection against immunodeficiency viruses and highlights the need to analyze these immune and genetic correlates of protection in future trials of HIV vaccine strategies. PMID:21543722
-
Immune and Genetic Correlates of Vaccine Protection Against Mucosal Infection by SIV in Monkeys.
Letvin, Norman L; Rao, Srinivas S; Montefiori, David C; Seaman, Michael S; Sun, Yue; Lim, So-Yon; Yeh, Wendy W; Asmal, Mohammed; Gelman, Rebecca S; Shen, Ling; Whitney, James B; Seoighe, Cathal; Lacerda, Miguel; Keating, Sheila; Norris, Philip J; Hudgens, Michael G; Gilbert, Peter B; Buzby, Adam P; Mach, Linh V; Zhang, Jinrong; Balachandran, Harikrishnan; Shaw, George M; Schmidt, Stephen D; Todd, John-Paul; Dodson, Alan; Mascola, John R; Nabel, Gary J
2011-05-04
The RV144 vaccine trial in Thailand demonstrated that an HIV vaccine could prevent infection in humans and highlights the importance of understanding protective immunity against HIV. We used a nonhuman primate model to define immune and genetic mechanisms of protection against mucosal infection by the simian immunodeficiency virus (SIV). A plasmid DNA prime/recombinant adenovirus serotype 5 (rAd5) boost vaccine regimen was evaluated for its ability to protect monkeys from infection by SIVmac251 or SIVsmE660 isolates after repeat intrarectal challenges. Although this prime-boost vaccine regimen failed to protect against SIVmac251 infection, 50% of vaccinated monkeys were protected from infection with SIVsmE660. Among SIVsmE660-infected animals, there was about a one-log reduction in peak plasma virus RNA in monkeys expressing the major histocompatibility complex class I allele Mamu-A*01, implicating cytotoxic T lymphocytes in the control of SIV replication once infection is established. Among Mamu-A*01-negative monkeys challenged with SIVsmE660, no CD8(+) T cell response or innate immune response was associated with protection against virus acquisition. However, low levels of neutralizing antibodies and an envelope-specific CD4(+) T cell response were associated with vaccine protection in these monkeys. Moreover, monkeys that expressed two TRIM5 alleles that restrict SIV replication were more likely to be protected from infection than monkeys that expressed at least one permissive TRIM5 allele. This study begins to elucidate the mechanisms of vaccine protection against immunodeficiency viruses and highlights the need to analyze these immune and genetic correlates of protection in future trials of HIV vaccine strategies.
-
DOE Office of Scientific and Technical Information (OSTI.GOV)
Eyre, Nicholas S., E-mail: nicholas.eyre@adelaide.edu.au; Centre for Cancer Biology, SA Pathology, Adelaide; Hampton-Smith, Rachel J.
Hepatitis C virus (HCV) NS5A protein is essential for HCV RNA replication and virus assembly. Here we report the identification of NS5A phosphorylation sites Ser-222, Ser-235 and Thr-348 during an infectious HCV replication cycle and demonstrate that Ser-235 phosphorylation is essential for HCV RNA replication. Confocal microscopy revealed that both phosphoablatant (S235A) and phosphomimetic (S235D) mutants redistribute NS5A to large juxta-nuclear foci that display altered colocalization with known replication complex components. Using electron microscopy (EM) we found that S235D alters virus-induced membrane rearrangements while EM using ‘APEX2’-tagged viruses demonstrated S235D-mediated enrichment of NS5A in irregular membranous foci. Finally, using amore » customized siRNA screen of candidate NS5A kinases and subsequent analysis using a phospho-specific antibody, we show that phosphatidylinositol-4 kinase III alpha (PI4KIIIα) is important for Ser-235 phosphorylation. We conclude that Ser-235 phosphorylation of NS5A is essential for HCV RNA replication and normal replication complex formation and is regulated by PI4KIIIα. - Highlights: • NS5A residues Ser-222, Ser-235 and Thr-348 are phosphorylated during HCV infection. • Phosphorylation of Ser-235 is essential to HCV RNA replication. • Mutation of Ser-235 alters replication compartment localization and morphology. • Phosphatidylinositol-4 kinase III alpha is important for Ser-235 phosphorylation.« less
-
Thomas, Michael A; Song, Rui; Demberg, Thorsten; Vargas-Inchaustegui, Diego A; Venzon, David; Robert-Guroff, Marjorie
2013-01-01
The global health burden engendered by human immunodeficiency virus (HIV)-induced acquired immunodeficiency syndrome (AIDS) is a sobering reminder of the pressing need for a preventative vaccine. In non-human primate models replicating adenovirus (Ad)-HIV/SIV recombinant vaccine vectors have been shown to stimulate potent immune responses culminating in protection against challenge exposures. Nonetheless, an increase in the transgene carrying capacity of these Ad vectors, currently limited to approximately 3000 base pairs, would greatly enhance their utility. Using a replicating, E3-deleted Ad type 5 host range mutant (Ad5 hr) encoding full-length single-chain HIVBaLgp120 linked to the D1 and D2 domains of rhesus macaque CD4 (rhFLSC) we systematically deleted the genes encoding early region 4 open reading frame 1 (E4orf1) through E4orf4. All the Ad-rhFLSC vectors produced similar levels of viral progeny. Cell cycle analysis of infected human and monkey cells revealed no differences in virus-host interaction. The parental and E4-deleted viruses expressed comparable levels of the transgene with kinetics similar to Ad late proteins. Similar levels of cellular immune responses and transgene-specific antibodies were elicited in vaccinated mice. However, differences in recognition of Ad proteins and induced antibody subtypes were observed, suggesting that the E4 gene products might modulate antibody responses by as yet unknown mechanisms. In short, we have improved the transgene carrying capacity by one thousand base pairs while preserving the replicability, levels of transgene expression, and immunogenicity critical to these vaccine vectors. This additional space allows for flexibility in vaccine design that could not be obtained with the current vector and as such should facilitate the goal of improving vaccine efficacy. To the best of our knowledge, this is the first report describing the effects of these E4 deletions on transgene expression and immunogenicity in a replicating Ad vector.
-
Thomas, Michael A.; Song, Rui; Demberg, Thorsten; Vargas-Inchaustegui, Diego A.; Venzon, David; Robert-Guroff, Marjorie
2013-01-01
The global health burden engendered by human immunodeficiency virus (HIV)-induced acquired immunodeficiency syndrome (AIDS) is a sobering reminder of the pressing need for a preventative vaccine. In non-human primate models replicating adenovirus (Ad)-HIV/SIV recombinant vaccine vectors have been shown to stimulate potent immune responses culminating in protection against challenge exposures. Nonetheless, an increase in the transgene carrying capacity of these Ad vectors, currently limited to approximately 3000 base pairs, would greatly enhance their utility. Using a replicating, E3-deleted Ad type 5 host range mutant (Ad5 hr) encoding full-length single-chain HIVBaLgp120 linked to the D1 and D2 domains of rhesus macaque CD4 (rhFLSC) we systematically deleted the genes encoding early region 4 open reading frame 1 (E4orf1) through E4orf4. All the Ad-rhFLSC vectors produced similar levels of viral progeny. Cell cycle analysis of infected human and monkey cells revealed no differences in virus-host interaction. The parental and E4-deleted viruses expressed comparable levels of the transgene with kinetics similar to Ad late proteins. Similar levels of cellular immune responses and transgene-specific antibodies were elicited in vaccinated mice. However, differences in recognition of Ad proteins and induced antibody subtypes were observed, suggesting that the E4 gene products might modulate antibody responses by as yet unknown mechanisms. In short, we have improved the transgene carrying capacity by one thousand base pairs while preserving the replicability, levels of transgene expression, and immunogenicity critical to these vaccine vectors. This additional space allows for flexibility in vaccine design that could not be obtained with the current vector and as such should facilitate the goal of improving vaccine efficacy. To the best of our knowledge, this is the first report describing the effects of these E4 deletions on transgene expression and immunogenicity in a replicating Ad vector. PMID:24143187
-
Adeno-associated virus type 2 enhances goose parvovirus replication in embryonated goose eggs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Malkinson, Mertyn; Winocour, Ernest
The autonomous goose parvovirus (GPV) and the human helper-dependent adeno-associated virus type 2 (AAV2) share a high degree of homology. To determine if this evolutionary relationship has a biological impact, we studied viral replication in human 293 cells and in embryonated goose eggs coinfected with both viruses. Similar experiments were performed with the minute virus of mice (MVM), an autonomous murine parvovirus with less homology to AAV2. In human 293 cells, both GPV and MVM augmented AAV2 replication. In contrast, AAV2 markedly enhanced GPV replication in embryonated goose eggs under conditions where a similar effect was not observed with MVM.more » AAV2 did not replicate in embryonated goose eggs and AAV2 inactivated by UV-irradiation also enhanced GPV replication. To our knowledge, this is the first report that a human helper-dependent member of the Parvoviridae can provide helper activity for an autonomous parvovirus in a natural host.« less
-
All-atom molecular dynamics of virus capsids as drug targets
Perilla, Juan R.; Hadden, Jodi A.; Goh, Boon Chong; ...
2016-04-29
Virus capsids are protein shells that package the viral genome. Although their morphology and biological functions can vary markedly, capsids often play critical roles in regulating viral infection pathways. A detailed knowledge of virus capsids, including their dynamic structure, interactions with cellular factors, and the specific roles that they play in the replication cycle, is imperative for the development of antiviral therapeutics. The following Perspective introduces an emerging area of computational biology that focuses on the dynamics of virus capsids and capsid–protein assemblies, with particular emphasis on the effects of small-molecule drug binding on capsid structure, stability, and allosteric pathways.more » When performed at chemical detail, molecular dynamics simulations can reveal subtle changes in virus capsids induced by drug molecules a fraction of their size. Finally, the current challenges of performing all-atom capsid–drug simulations are discussed, along with an outlook on the applicability of virus capsid simulations to reveal novel drug targets.« less
-
Schuh, Amy J; Amman, Brian R; Sealy, Tara K; Spengler, Jessica R; Nichol, Stuart T; Towner, Jonathan S
2017-08-18
Although bats are natural reservoir hosts for numerous zoonotic viruses, little is known about the long-term dynamics of the host immune response following infection and how these viruses are maintained in nature. The Egyptian rousette bat (ERB) is a known reservoir host for Marburg virus (MARV). Following infection of ERBs with MARV, virus-specific IgG antibodies are induced but rapidly wane and by 3 months post-infection the bats are seronegative. To determine whether reinfection of ERBs plays a role in MARV maintenance, we challenge groups of ERBs that were "naturally" or experimentally infected with MARV 17-24 months prior. No bats in either group exhibit evidence of MARV replication or shedding and all bats develop virus-specific secondary immune responses. This study demonstrates that infection of ERBs with MARV induces long-term protective immunity against reinfection and indicates that other factors, such as host population dynamics, drive MARV maintenance in nature.
-
All-atom molecular dynamics of virus capsids as drug targets
DOE Office of Scientific and Technical Information (OSTI.GOV)
Perilla, Juan R.; Hadden, Jodi A.; Goh, Boon Chong
Virus capsids are protein shells that package the viral genome. Although their morphology and biological functions can vary markedly, capsids often play critical roles in regulating viral infection pathways. A detailed knowledge of virus capsids, including their dynamic structure, interactions with cellular factors, and the specific roles that they play in the replication cycle, is imperative for the development of antiviral therapeutics. The following Perspective introduces an emerging area of computational biology that focuses on the dynamics of virus capsids and capsid–protein assemblies, with particular emphasis on the effects of small-molecule drug binding on capsid structure, stability, and allosteric pathways.more » When performed at chemical detail, molecular dynamics simulations can reveal subtle changes in virus capsids induced by drug molecules a fraction of their size. Finally, the current challenges of performing all-atom capsid–drug simulations are discussed, along with an outlook on the applicability of virus capsid simulations to reveal novel drug targets.« less
-
Al-Mulla, Hawaa M N; Turrell, Lauren; Smith, Nicola M; Payne, Luke; Baliji, Surendranath; Züst, Roland; Thiel, Volker; Baker, Susan C; Siddell, Stuart G; Neuman, Benjamin W
2014-04-01
Positive-stranded viruses synthesize their RNA in membrane-bound organelles, but it is not clear how this benefits the virus or the host. For coronaviruses, these organelles take the form of double-membrane vesicles (DMVs) interconnected by a convoluted membrane network. We used electron microscopy to identify murine coronaviruses with mutations in nsp3 and nsp14 that replicated normally while producing only half the normal amount of DMVs under low-temperature growth conditions. Viruses with mutations in nsp5 and nsp16 produced small DMVs but also replicated normally. Quantitative reverse transcriptase PCR (RT-PCR) confirmed that the most strongly affected of these, the nsp3 mutant, produced more viral RNA than wild-type virus. Competitive growth assays were carried out in both continuous and primary cells to better understand the contribution of DMVs to viral fitness. Surprisingly, several viruses that produced fewer or smaller DMVs showed a higher fitness than wild-type virus at the reduced temperature, suggesting that larger and more numerous DMVs do not necessarily confer a competitive advantage in primary or continuous cell culture. For the first time, this directly demonstrates that replication and organelle formation may be, at least in part, studied separately during infection with positive-stranded RNA virus. IMPORTANCE The viruses that cause severe acute respiratory syndrome (SARS), poliomyelitis, and hepatitis C all replicate in double-membrane vesicles (DMVs). The big question about DMVs is why they exist in the first place. In this study, we looked at thousands of infected cells and identified two coronavirus mutants that made half as many organelles as normal and two others that made typical numbers but smaller organelles. Despite differences in DMV size and number, all four mutants replicated as efficiently as wild-type virus. To better understand the relative importance of replicative organelles, we carried out competitive fitness experiments. None of these viruses was found to be significantly less fit than wild-type, and two were actually fitter in tests in two kinds of cells. This suggests that viruses have evolved to have tremendous plasticity in the ability to form membrane-associated replication complexes and that large and numerous DMVs are not exclusively associated with efficient coronavirus replication.
-
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bernard, Eric; Hamel, Rodolphe; Neyret, Aymeric
Transmission of chikungunya virus (CHIKV) to humans is initiated by puncture of the skin by a blood-feeding Aedes mosquito. Despite the growing knowledge accumulated on CHIKV, the interplay between skin cells and CHIKV following inoculation still remains unclear. In this study we questioned the behavior of human keratinocytes, the predominant cell population in the skin, following viral challenge. We report that CHIKV rapidly elicits an innate immune response in these cells leading to the enhanced transcription of type I/II and type III interferon genes. Concomitantly, we show that despite viral particles internalization into Rab5-positive endosomes and efficient fusion of virusmore » and cell membranes, keratinocytes poorly replicate CHIKV as attested by absence of nonstructural proteins and genomic RNA synthesis. Accordingly, human keratinocytes behave as an antiviral defense against CHIKV infection rather than as a primary targets for initial replication. This picture significantly differs from that reported for Dengue and West Nile mosquito-borne viruses. - Highlights: • Human keratinocytes support endocytosis of CHIKV and fusion of viral membranes. • CHIKV replication is blocked at a post entry step in these cells. • Infection upregulates type-I, –II and –III IFN genes expression. • Keratinocytes behave as immune sentinels against CHIKV.« less
-
Wolbachia wStri Blocks Zika Virus Growth at Two Independent Stages of Viral Replication.
Schultz, M J; Tan, A L; Gray, C N; Isern, S; Michael, S F; Frydman, H M; Connor, J H
2018-05-22
Mosquito-transmitted viruses are spread globally and present a great risk to human health. Among the many approaches investigated to limit the diseases caused by these viruses are attempts to make mosquitos resistant to virus infection. Coinfection of mosquitos with the bacterium Wolbachia pipientis from supergroup A is a recent strategy employed to reduce the capacity for major vectors in the Aedes mosquito genus to transmit viruses, including dengue virus (DENV), Chikungunya virus (CHIKV), and Zika virus (ZIKV). Recently, a supergroup B Wolbachia w Stri, isolated from Laodelphax striatellus , was shown to inhibit multiple lineages of ZIKV in Aedes albopictus cells. Here, we show that w Stri blocks the growth of positive-sense RNA viruses DENV, CHIKV, ZIKV, and yellow fever virus by greater than 99.9%. w Stri presence did not affect the growth of the negative-sense RNA viruses LaCrosse virus or vesicular stomatitis virus. Investigation of the stages of the ZIKV life cycle inhibited by w Stri identified two distinct blocks in viral replication. We found a reduction of ZIKV entry into w Stri-infected cells. This was partially rescued by the addition of a cholesterol-lipid supplement. Independent of entry, transfected viral genome was unable to replicate in Wolbachia -infected cells. RNA transfection and metabolic labeling studies suggested that this replication defect is at the level of RNA translation, where we saw a 66% reduction in mosquito protein synthesis in w Stri-infected cells. This study's findings increase the potential for application of w Stri to block additional arboviruses and also identify specific blocks in viral infection caused by Wolbachia coinfection. IMPORTANCE Dengue, Zika, and yellow fever viruses are mosquito-transmitted diseases that have spread throughout the world, causing millions of infections and thousands of deaths each year. Existing programs that seek to contain these diseases through elimination of the mosquito population have so far failed, making it crucial to explore new ways of limiting the spread of these viruses. Here, we show that introduction of an insect symbiont, Wolbachia w Stri, into mosquito cells is highly effective at reducing yellow fever virus, dengue virus, Zika virus, and Chikungunya virus production. Reduction of virus replication was attributable to decreases in entry and a strong block of virus gene expression at the translational level. These findings expand the potential use of Wolbachia w Stri to block viruses and identify two separate steps for limiting virus replication in mosquitos that could be targeted via microbes or other means as an antiviral strategy. Copyright © 2018 Schultz et al.
-
Studies on Sam68 a cell factor involved in the life cycle of foot-and-mouth disease virus
USDA-ARS?s Scientific Manuscript database
As with other RNA viruses, Foot-and-Mouth Disease Virus (FMDV) recruits various host cell factors to assist in translation and replication of the virus genome. While FMDV translation has been thoroughly investigated, much remains unknown regarding replication of the positive-sense RNA genome. In th...
-
Eilat virus host range restriction is present at multiple levels of the virus life cycle.
Nasar, Farooq; Gorchakov, Rodion V; Tesh, Robert B; Weaver, Scott C
2015-01-15
Most alphaviruses are mosquito-borne and exhibit a broad host range, infecting many different vertebrates, including birds, rodents, equids, humans, and nonhuman primates. This ability of most alphaviruses to infect arthropods and vertebrates is essential for their maintenance in nature. Recently, a new alphavirus, Eilat virus (EILV), was described, and in contrast to all other mosquito-borne viruses, it is unable to replicate in vertebrate cell lines. Investigations into the nature of its host range restriction showed the inability of genomic EILV RNA to replicate in vertebrate cells. Here, we investigated whether the EILV host range restriction is present at the entry level and further explored the viral factors responsible for the lack of genomic RNA replication. Utilizing Sindbis virus (SINV) and EILV chimeras, we show that the EILV vertebrate host range restriction is also manifested at the entry level. Furthermore, the EILV RNA replication restriction is independent of the 3' untranslated genome region (UTR). Complementation experiments with SINV suggested that RNA replication is restricted by the inability of the EILV nonstructural proteins to form functional replicative complexes. These data demonstrate that the EILV host range restriction is multigenic, involving at least one gene from both nonstructural protein (nsP) and structural protein (sP) open reading frames (ORFs). As EILV groups phylogenetically within the mosquito-borne virus clade of pathogenic alphaviruses, our findings have important evolutionary implications for arboviruses. Our work explores the nature of host range restriction of the first "mosquito-only alphavirus," EILV. EILV is related to pathogenic mosquito-borne viruses (Eastern equine encephalitis virus [EEEV], Western equine encephalitis virus [WEEV], Venezuelan equine encephalitis virus [VEEV], and Chikungunya virus [CHIKV]) that cause severe disease in humans. Our data demonstrate that EILV is restricted both at entry and genomic RNA replication levels in vertebrate cells. These findings have important implications for arbovirus evolution and will help elucidate the viral factors responsible for the broad host range of pathogenic mosquito-borne alphaviruses, facilitate vaccine development, and inform potential strategies to reduce/prevent alphavirus transmission. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
-
Work, Thierry M.; Dagenais, Julie; Balazs, George H.; Schettle, Nelli; Ackermann, Mathias
2015-01-01
Cancers in humans and animals can be caused by viruses, but virus-induced tumors are considered to be poor sites for replication of intact virions (lytic replication). Fibropapillomatosis (FP) is a neoplastic disease associated with a herpesvirus, chelonid herpesvirus 5 (ChHV5), that affects green turtles globally. ChHV5 probably replicates in epidermal cells of tumors, because epidermal intranuclear inclusions (EIIs) contain herpesvirus-like particles. However, although EIIs are a sign of herpesvirus replication, they have not yet been firmly linked to ChHV5. Moreover, the dynamics of viral shedding in turtles are unknown, and there are no serological reagents to confirm actual presence of the specific ChHV5 virus in tissues. The investigators analyzed 381 FP tumors for the presence of EIIs and found that overall, about 35% of green turtles had lytic replication in skin tumors with 7% of tumors showing lytic replication. A few (11%) turtles accounted for more than 30% cases having lytic viral replication, and lytic replication was more likely in smaller tumors. To confirm that turtles were actively replicating ChHV5, a prerequisite for shedding, the investigators used antiserum raised against F-VP26, a predicted capsid protein of ChHV5 that localizes to the host cell nucleus during viral replication. This antiserum revealed F-VP26 in EIIs of tumors, thus confirming the presence of replicating ChHV5. In this light, it is proposed that unlike other virus-induced neoplastic diseases, FP is a disease that may depend on superspreaders, a few highly infectious individuals growing numerous small tumors permissive to viral production, for transmission of ChHV5.
-
Work, T M; Dagenais, J; Balazs, G H; Schettle, N; Ackermann, M
2015-11-01
Cancers in humans and animals can be caused by viruses, but virus-induced tumors are considered to be poor sites for replication of intact virions (lytic replication). Fibropapillomatosis (FP) is a neoplastic disease associated with a herpesvirus, chelonid herpesvirus 5 (ChHV5), that affects green turtles globally. ChHV5 probably replicates in epidermal cells of tumors, because epidermal intranuclear inclusions (EIIs) contain herpesvirus-like particles. However, although EIIs are a sign of herpesvirus replication, they have not yet been firmly linked to ChHV5. Moreover, the dynamics of viral shedding in turtles are unknown, and there are no serological reagents to confirm actual presence of the specific ChHV5 virus in tissues. The investigators analyzed 381 FP tumors for the presence of EIIs and found that overall, about 35% of green turtles had lytic replication in skin tumors with 7% of tumors showing lytic replication. A few (11%) turtles accounted for more than 30% cases having lytic viral replication, and lytic replication was more likely in smaller tumors. To confirm that turtles were actively replicating ChHV5, a prerequisite for shedding, the investigators used antiserum raised against F-VP26, a predicted capsid protein of ChHV5 that localizes to the host cell nucleus during viral replication. This antiserum revealed F-VP26 in EIIs of tumors, thus confirming the presence of replicating ChHV5. In this light, it is proposed that unlike other virus-induced neoplastic diseases, FP is a disease that may depend on superspreaders, a few highly infectious individuals growing numerous small tumors permissive to viral production, for transmission of ChHV5. © The Author(s) 2014.
-
Shao, Qiang; Xu, Wenpin; Yan, Li; Liu, Jinhua; Rui, Lei; Xiao, Xiao; Yu, Xiaoxue; Lu, Yanan; Li, Zandong
2014-10-13
The avian influenza (AI) H9N2 virus and IBDV are two major problems in the poultry industry. They have been prevalent among domestic poultry in Asia for many years and have caused considerable economic losses. Retinoic-acid-induced gene I (RIG-I) is a cytoplasmic sensor of dsRNA and ssRNA. It can detect Encephalomyocarditis virus (EMCV) and vesicular stomatitis virus (VSV) in human cells, influenza virus in duck leads to production of IFN-β and IFN-stimulated antiviral genes and reductions in the replication of RNA virus. Chickens, which lack RIG-I, are more sensitive to influenza virus than ducks. However, little is known about the roles of duck RIG-I (dRIG-I) in the detection of IBDV and AI H9N2 in chicken cells DF-1. The purpose of this study was to examine the function of dRIG-I in the recognition of IBDV Ts strain and H9N2 A/Chicken/Shandong/ZB/2007(ZB07) and in the induction of antiviral gene expression to gain an understanding of antiviral ability of dRIG-I in chicken cells against dsRNA virus IBDV and ssRNA virus ZB07. After challenge with the IBDV Ts strain and ZB07 the expression levels of Type I IFN (IFN-β and IFN-α) and IFN-induced antiviral genes (Mx and PKR) were significantly up-regulated in dRIG-I-transfected DF-1cells compared with the empty-vector-transfected control. dRIG-I knockdown experiments further proved that dRIG-I is essential to sensing IBDV and ZB07 in duck embryo fibroblasts (DEF). Growth curves showed that dRIG-I repressed the replication of IBDV and almost blunted the growth of ZB07 in DF-1. Apoptosis analysis revealed that dRIG-I increase the number of the survival cells after IBDV Ts strain or ZB07 infection relative to the empty-vector-transfected control. These results indicate that dRIG-I can up-regulates type I IFN and reduce viral gene expression and viral replication and protect chicken cells from virus-induced apoptosis during ZB07 and IBDV infection. Copyright © 2014 Elsevier B.V. All rights reserved.
-
Endoplasmic Reticulum: The Favorite Intracellular Niche for Viral Replication and Assembly.
Romero-Brey, Inés; Bartenschlager, Ralf
2016-06-07
The endoplasmic reticulum (ER) is the largest intracellular organelle. It forms a complex network of continuous sheets and tubules, extending from the nuclear envelope (NE) to the plasma membrane. This network is frequently perturbed by positive-strand RNA viruses utilizing the ER to create membranous replication factories (RFs), where amplification of their genomes occurs. In addition, many enveloped viruses assemble progeny virions in association with ER membranes, and viruses replicating in the nucleus need to overcome the NE barrier, requiring transient changes of the NE morphology. This review first summarizes some key aspects of ER morphology and then focuses on the exploitation of the ER by viruses for the sake of promoting the different steps of their replication cycles.
-
Endoplasmic Reticulum: The Favorite Intracellular Niche for Viral Replication and Assembly
Romero-Brey, Inés; Bartenschlager, Ralf
2016-01-01
The endoplasmic reticulum (ER) is the largest intracellular organelle. It forms a complex network of continuous sheets and tubules, extending from the nuclear envelope (NE) to the plasma membrane. This network is frequently perturbed by positive-strand RNA viruses utilizing the ER to create membranous replication factories (RFs), where amplification of their genomes occurs. In addition, many enveloped viruses assemble progeny virions in association with ER membranes, and viruses replicating in the nucleus need to overcome the NE barrier, requiring transient changes of the NE morphology. This review first summarizes some key aspects of ER morphology and then focuses on the exploitation of the ER by viruses for the sake of promoting the different steps of their replication cycles. PMID:27338443
-
Morello, Christopher S; Kraynyak, Kimberly A; Levinson, Michael S; Chen, Zhijiang; Lee, Kuo-Fen; Spector, Deborah H
2012-10-12
Herpes Simplex Virus Type 2 (HSV-2) infection can result in life-long recurrent genital disease, asymptomatic virus shedding, and transmission. No vaccine to date has shown significant protection clinically. Here, we used a mouse model of genital HSV-2 infection to test the efficacy of a vaccine consisting of whole, formalin-inactivated HSV-2 (FI-HSV2) formulated with monophosphoryl lipid A (MPL) and alum adjuvants. Vaccine components were administered alone or as a prime-boost immunization together with DNA vaccines encoding a truncated glycoprotein D2 (gD2t) and two conserved HSV-2 genes necessary for virus replication, UL5 (DNA helicase) and UL30 (DNA polymerase). Our results show: (1) compared with mock immunized controls, mice immunized with FI-HSV2 plus MPL/alum consistently showed protection against disease burden and total viral shedding while the mice immunized with gD2t protein with MPL/alum did not; (2) protection against genital disease and viral replication correlated with the type of boost in a prime-boost immunization with little advantage afforded by a DNA prime; (3) intramuscular (i.m.) immunization with FI-HSV2 in MPL/Alhydrogel adjuvant provided nearly complete protection against vaginal HSV-2 shedding after a lethal intravaginal (i.vag.) short-term challenge and long-term rechallenge; (4) single formulation immunization with DNA vaccines, FI-HSV2, and MPL in an aluminum phosphate (Adju-Phos) adjuvant did not increase protection relative to FI-HSV2/MPL/Adju-Phos alone; and (5) addition of MPL/alum to the FI-HSV2 was required for optimal protection against disease, viral replication, and latent virus load in the dorsal root ganglia (DRG). Most notably, an optimized vaccine formulation of FI-HSV2 MPL/Alhydrogel given i.m. completely protected against detectable vaginal HSV-2 shedding in the majority of animals and HSV-2 latent DNA in the DRG of all animals. Copyright © 2012 Elsevier Ltd. All rights reserved.
-
Parker, Scott; Crump, Ryan; Foster, Scott; Hartzler, Hollyce; Hembrador, Ed; Lanier, E Randall; Painter, George; Schriewer, Jill; Trost, Lawrence C; Buller, R Mark
2014-11-01
Natural orthopoxvirus outbreaks such as vaccinia, cowpox, cattlepox and buffalopox continue to cause morbidity in the human population. Monkeypox virus remains a significant agent of morbidity and mortality in Africa. Furthermore, monkeypox virus's broad host-range and expanding environs make it of particular concern as an emerging human pathogen. Monkeypox virus and variola virus (the etiological agent of smallpox) are both potential agents of bioterrorism. The first line response to orthopoxvirus disease is through vaccination with first-generation and second-generation vaccines, such as Dryvax and ACAM2000. Although these vaccines provide excellent protection, their widespread use is impeded by the high level of adverse events associated with vaccination using live, attenuated virus. It is possible that vaccines could be used in combination with antiviral drugs to reduce the incidence and severity of vaccine-associated adverse events, or as a preventive in individuals with uncertain exposure status or contraindication to vaccination. We have used the intranasal mousepox (ectromelia) model to evaluate the efficacy of vaccination with Dryvax or ACAM2000 in conjunction with treatment using the broad spectrum antiviral, brincidofovir (BCV, CMX001). We found that co-treatment with BCV reduced the severity of vaccination-associated lesion development. Although the immune response to vaccination was quantifiably attenuated, vaccination combined with BCV treatment did not alter the development of full protective immunity, even when administered two days following ectromelia challenge. Studies with a non-replicating vaccine, ACAM3000 (MVA), confirmed that BCV's mechanism of attenuating the immune response following vaccination with live virus was, as expected, by limiting viral replication and not through inhibition of the immune system. These studies suggest that, in the setting of post-exposure prophylaxis, co-administration of BCV with vaccination should be considered a first response to a smallpox emergency in subjects of uncertain exposure status or as a means of reduction of the incidence and severity of vaccine-associated adverse events. Copyright © 2014 Elsevier B.V. All rights reserved.
-
Cromwell, Mandy A.; Veazey, Ronald S.; Altman, John D.; Mansfield, Keith G.; Glickman, Rhona; Allen, Todd M.; Watkins, David I.; Lackner, Andrew A.; Johnson, R. Paul
2000-01-01
Induction of virus-specific T-cell responses in mucosal as well as systemic compartments of the immune system is likely to be a critical feature of an effective AIDS vaccine. We investigated whether virus-specific CD8+ lymphocytes induced in rhesus macaques by immunization with attenuated simian immunodeficiency virus (SIV), an approach that is highly effective in eliciting protection against mucosal challenge, express the mucosa-homing receptor α4β7 and traffic to the intestinal mucosa. SIV-specific CD8+ T cells expressing α4β7 were detected in peripheral blood and intestine of macaques infected with attenuated SIV. In contrast, virus-specific T cells in blood of animals immunized cutaneously by a combined DNA-modified vaccinia virus Ankara regimen did not express α4β7. These results demonstrate the selective induction of SIV-specific CD8+ T lymphocytes expressing α4β7 by a vaccine approach that replicates in mucosal tissue and suggest that induction of virus-specific lymphocytes that are able to home to mucosal sites may be an important characteristic of a successful AIDS vaccine. PMID:10954580
-
Ambrose, R L; Mackenzie, J M
2015-07-01
The West Nile virus strain Kunjin virus (WNVKUN) NS4A protein is a multifunctional protein involved in many aspects of the virus life-cycle and is a major component of the WNVKUN replication complex (RC). Previously we identified a conserved region in the C-terminus of NS4A regulating proteolytic processing and RC assembly, and now investigate key conserved residues in the N-terminus of NS4A and their contribution to WNVKUN replication. Mutation of P13 completely ablated replication, whereas, mutation of P48 and D49, near the first transmembrane helix, and G66 within the helix, showed variable defects in replication, virion secretion and membrane proliferation. Intriguingly, the P48 and G66 NS4A mutants resulted in specific proteasome depletion of NS4A that could in part be rescued with a proteasome inhibitor. Our results suggest that the N-terminus of NS4A contributes to correct folding and stability, essential for facilitating the essential roles of NS4A during replication. Copyright © 2015 Elsevier Inc. All rights reserved.
-
Dengue virus replicates and accumulates in Aedes aegypti salivary glands
DOE Office of Scientific and Technical Information (OSTI.GOV)
Raquin, Vincent, E-mail: vincent.raquin@univ-lyon1
Dengue virus (DENV) is an RNA virus transmitted among humans by mosquito vectors, mainly Aedes aegypti. DENV transmission requires viral dissemination from the mosquito midgut to the salivary glands. During this process the virus undergoes several population bottlenecks, which are stochastic reductions in population size that restrict intra-host viral genetic diversity and limit the efficiency of natural selection. Despite the implications for virus transmission and evolution, DENV replication in salivary glands has not been directly demonstrated. Here, we used a strand-specific quantitative RT-PCR assay to demonstrate that negative-strand DENV RNA is produced in Ae. aegypti salivary glands, providing conclusive evidencemore » that viral replication occurs in this tissue. Furthermore, we showed that the concentration of DENV genomic RNA in salivary glands increases significantly over time, indicating that active replication likely replenishes DENV genetic diversity prior to transmission. These findings improve our understanding of the biological determinants of DENV fitness and evolution. - Highlights: •Strand-specific RT-qPCR allows accurate quantification of DENV (-) RNA in mosquito tissues. •Detection of DENV (-) RNA in salivary glands provides evidence of viral replication in this tissue. •Viral replication in salivary glands likely replenishes DENV genetic diversity prior to transmission.« less
-
MicroRNA Regulation of Human Protease Genes Essential for Influenza Virus Replication
Meliopoulos, Victoria A.; Andersen, Lauren E.; Brooks, Paula; Yan, Xiuzhen; Bakre, Abhijeet; Coleman, J. Keegan; Tompkins, S. Mark; Tripp, Ralph A.
2012-01-01
Influenza A virus causes seasonal epidemics and periodic pandemics threatening the health of millions of people each year. Vaccination is an effective strategy for reducing morbidity and mortality, and in the absence of drug resistance, the efficacy of chemoprophylaxis is comparable to that of vaccines. However, the rapid emergence of drug resistance has emphasized the need for new drug targets. Knowledge of the host cell components required for influenza replication has been an area targeted for disease intervention. In this study, the human protease genes required for influenza virus replication were determined and validated using RNA interference approaches. The genes validated as critical for influenza virus replication were ADAMTS7, CPE, DPP3, MST1, and PRSS12, and pathway analysis showed these genes were in global host cell pathways governing inflammation (NF-κB), cAMP/calcium signaling (CRE/CREB), and apoptosis. Analyses of host microRNAs predicted to govern expression of these genes showed that eight miRNAs regulated gene expression during virus replication. These findings identify unique host genes and microRNAs important for influenza replication providing potential new targets for disease intervention strategies. PMID:22606348
-
Workenhe, Samuel T; Simmons, Graydon; Pol, Jonathan G; Lichty, Brian D; Halford, William P; Mossman, Karen L
2014-01-01
Within the oncolytic virus field, the extent of virus replication that is essential for immune stimulation to control tumor growth remains unresolved. Using infected cell protein 0 (ICP0)-defective oncolytic Herpes simplex virus type 1 (HSV-1) and HSV-2 viruses (dICP0 and dNLS) that show differences in their in vitro replication and cytotoxicity, we investigated the inherent features of oncolytic HSV viruses that are required for potent antitumor activity. In vitro, the HSV-2 vectors showed rapid cytotoxicity despite lower viral burst sizes compared to HSV-1 vectors. In vivo, although both of the dICP0 vectors initially replicated to a similar level, HSV-1 dICP0 was rapidly cleared from the tumors. In spite of this rapid clearance, HSV-1 dICP0 treatment conferred significant survival benefit. HSV-1 dICP0-treated tumors showed significantly higher levels of danger-associated molecular patterns that correlated with higher numbers of antigen-presenting cells within the tumor and increased antigen-specific CD8+ T-cell levels in the peripheral blood. This study suggests that, at least in the context of oncolytic HSV, the initial stages of immunogenic virus replication leading to activation of antitumor immunity are more important than persistence of a replicating virus within the tumor. This knowledge provides important insight for the design of therapeutically successful oncolytic viruses.
-
Whitt, Michael A; Geisbert, Thomas W; Mire, Chad E
2016-01-01
There are many avenues for making an effective vaccine against viruses. Depending on the virus these can include one of the following: inactivation of whole virions; attenuation of viruses; recombinant viral proteins; non-replication-competent virus particles; or surrogate virus vector systems such as vesicular stomatitis virus (VSV). VSV is a prototypic enveloped animal virus that has been used for over four decades to study virus replication, entry, and assembly due to its ability to replicate to high titers in a wide variety of mammalian and insect cells. The use of reverse genetics to recover infectious and single-cycle replicating VSV from plasmid DNA transfected in cell culture began a revolution in the study of recombinant VSV (rVSV). This platform can be manipulated to study the viral genetic sequences and proteins important in the virus life cycle. Additionally, foreign genes can be inserted between naturally occurring or generated start/stop signals and polyadenylation sites within the VSV genome. VSV has a tolerance for foreign gene expression which has led to numerous rVSVs reported in the literature. Of particular interest are the very effective single-dose rVSV vaccine vectors against high-containment viruses such as filoviruses, henipaviruses, and arenaviruses. Herein we describe the methods for selecting foreign antigenic genes, selecting the location within the VSV genome for insertion, generation of rVSV using reverse genetics, and proper vaccine study designs.
-
Replication of Heliothis virescens ascovirus in insect cell lines.
Asgari, S
2006-09-01
Ascoviruses (AVs) infect larvae of various insect pests belonging to the family Noctuidae. The result of AV infection in the hosts is cleavage of infected cells into vesicles, a unique feature of AV infection. Since insect cell lines facilitate the study of virus life cycles, attempts were made to analyze Heliothis virescens AV (HvAV3e) infection in several cell lines and compare cell pathology to larval infection. In this study, replication and cytopathological effects of HvAV3e on four different cell lines were investigated. HvAV3e replication was confirmed in three noctuid cell lines from Spodoptera frugiperda (Sf9) and Helicoverpa zea (BCIRL-Hz-AM1 and FB33). However, the virus did not replicate in the non-noctuid insect cell line from Pieris rapae (Pieridae). Despite replication of the virus in the three permissive cell lines, the cytopathological effects of the virus were significantly different from that of larval infection.
-
Replication-Competent Influenza A Viruses Expressing Reporter Genes.
Breen, Michael; Nogales, Aitor; Baker, Steven F; Martínez-Sobrido, Luis
2016-06-23
Influenza A viruses (IAV) cause annual seasonal human respiratory disease epidemics. In addition, IAV have been implicated in occasional pandemics with inordinate health and economic consequences. Studying IAV, in vitro or in vivo, requires the use of laborious secondary methodologies to identify virus-infected cells. To circumvent this requirement, replication-competent IAV expressing an easily traceable reporter protein can be used. Here we discuss the development and applications of recombinant replication-competent IAV harboring diverse fluorescent or bioluminescent reporter genes in different locations of the viral genome. These viruses have been employed for in vitro and in vivo studies, such as the screening of neutralizing antibodies or antiviral compounds, the identification of host factors involved in viral replication, cell tropism, the development of vaccines, or the assessment of viral infection dynamics. In summary, reporter-expressing, replicating-competent IAV represent a powerful tool for the study of IAV both in vitro and in vivo.
-
Replication-Competent Influenza A Viruses Expressing Reporter Genes
Breen, Michael; Nogales, Aitor; Baker, Steven F.; Martínez-Sobrido, Luis
2016-01-01
Influenza A viruses (IAV) cause annual seasonal human respiratory disease epidemics. In addition, IAV have been implicated in occasional pandemics with inordinate health and economic consequences. Studying IAV, in vitro or in vivo, requires the use of laborious secondary methodologies to identify virus-infected cells. To circumvent this requirement, replication-competent IAV expressing an easily traceable reporter protein can be used. Here we discuss the development and applications of recombinant replication-competent IAV harboring diverse fluorescent or bioluminescent reporter genes in different locations of the viral genome. These viruses have been employed for in vitro and in vivo studies, such as the screening of neutralizing antibodies or antiviral compounds, the identification of host factors involved in viral replication, cell tropism, the development of vaccines, or the assessment of viral infection dynamics. In summary, reporter-expressing, replicating-competent IAV represent a powerful tool for the study of IAV both in vitro and in vivo. PMID:27347991
-
Miorin, Lisa; Romero-Brey, Inés; Maiuri, Paolo; Hoppe, Simone; Krijnse-Locker, Jacomine; Bartenschlager, Ralf; Marcello, Alessandro
2013-06-01
Flavivirus replication is accompanied by the rearrangement of cellular membranes that may facilitate viral genome replication and protect viral components from host cell responses. The topological organization of viral replication sites and the fate of replicated viral RNA are not fully understood. We exploited electron microscopy to map the organization of tick-borne encephalitis virus (TBEV) replication compartments in infected cells and in cells transfected with a replicon. Under both conditions, 80-nm vesicles were seen within the lumen of the endoplasmic reticulum (ER) that in infected cells also contained virions. By electron tomography, the vesicles appeared as invaginations of the ER membrane, displaying a pore that could enable release of newly synthesized viral RNA into the cytoplasm. To track the fate of TBEV RNA, we took advantage of our recently developed method of viral RNA fluorescent tagging for live-cell imaging combined with bleaching techniques. TBEV RNA was found outside virus-induced vesicles either associated to ER membranes or free to move within a defined area of juxtaposed ER cisternae. From our results, we propose a biologically relevant model of the possible topological organization of flavivirus replication compartments composed of replication vesicles and a confined extravesicular space where replicated viral RNA is retained. Hence, TBEV modifies the ER membrane architecture to provide a protected environment for viral replication and for the maintenance of newly replicated RNA available for subsequent steps of the virus life cycle.
-
Enhanced replication of herpes simplex virus type 1 in human cells
DOE Office of Scientific and Technical Information (OSTI.GOV)
Miller, C.S.; Smith, K.O.
1991-02-01
The effects of DNA-damaging agents on the replication of herpes simplex virus type 1 (HSV-1) were assessed in vitro. Monolayers of human lung fibroblast cell lines were exposed to DNA-damaging agents (methyl methanesulfonate (MMS), methyl methanethiosulfonate (MMTS), ultraviolet light (UV), or gamma radiation (GR)) at specific intervals, before or after inoculation with low levels of HSV-1. The ability of cell monolayers to support HSV-1 replication was measured by direct plaque assay and was compared with that of untreated control samples. In this system, monolayers of different cell lines infected with identical HSV-1 strains demonstrated dissimilar levels of recovery of themore » infectious virus. Exposure of DNA-repair-competent cell cultures to DNA-damaging agents produced time-dependent enhanced virus replication. Treatment with agent before virus inoculation significantly (p less than 0.025) increased the number of plaques by 10 to 68%, compared with untreated control cultures, while treatment with agent after virus adsorption significantly increased (p less than 0.025) the number of plaques by 7 to 15%. In a parallel series of experiments, cells deficient in DNA repair (xeroderma pigmentosum) failed to support enhanced virus replication. These results suggest that after exposure to DNA-damaging agents, fibroblasts competent in DNA repair amplify the replication of HSV-1, and that DNA-repair mechanisms that act on a variety of chromosomal lesions may be involved in the repair and biological activation of HSV-1 genomes.« less
-
Intestinal replication of influenza A viruses in two mammalian species. Brief report.
Kawaoka, Y; Bordwell, E; Webster, R G
1987-01-01
The sites of replication of influenza A viruses in ferrets and pigs were studied. The majority of the swine, equine, and avian influenza A viruses tested were recovered from the intestinal tract of ferrets as well as from the respiratory tract; most of the human influenza viruses studied were recovered only from the respiratory tract. In contrast with ferrets, only Hong Kong/1/68 (H 3 N 2) influenza virus was recovered from the intestinal tract of pigs. Despite the large biological variability found in ferrets and in pigs, the results do establish that the majority of influenza viruses have the potential to replicate in the intestinal tissues of some mammals. Additionally, the study suggests that there are differences among the influenza A viruses in tissue tropism in different mammals. Both viral and host genetic factors determine the tissue tropism of influenza viruses in mammals.
-
Viral Interference and Persistence in Mosquito-Borne Flaviviruses.
Salas-Benito, Juan Santiago; De Nova-Ocampo, Mónica
2015-01-01
Mosquito-borne flaviviruses are important pathogens for humans, and the detection of two or more flaviviruses cocirculating in the same geographic area has often been reported. However, the epidemiological impact remains to be determined. Mosquito-borne flaviviruses are primarily transmitted through Aedes and Culex mosquitoes; these viruses establish a life-long or persistent infection without apparent pathological effects. This establishment requires a balance between virus replication and the antiviral host response. Viral interference is a phenomenon whereby one virus inhibits the replication of other viruses, and this condition is frequently associated with persistent infections. Viral interference and persistent infection are determined by several factors, such as defective interfering particles, competition for cellular factors required for translation/replication, and the host antiviral response. The interaction between two flaviviruses typically results in viral interference, indicating that these viruses share common features during the replicative cycle in the vector. The potential mechanisms involved in these processes are reviewed here.
-
Ogura, Fumie; Hayashi, Kyoko; Lee, Jung-Bum; Kanekiyo, Kenji; Hayashi, Toshimitsu
2010-01-01
A hot-water extract of Aphanothece sacrum, an edible aquacultured blue-green alga, was found to show a remarkable inhibitory effect on the replication of enveloped viruses including herpes simplex virus type 2 (HSV-2) and influenza virus type A (IFV-A, H1N1) in vitro. The main active components were suggested to be sulfated polysaccharides in non-dialyzable portion (ASWPH). ASWPH was found to inhibit the viral adsorption to the receptor of the host cells involved in the replication process of HSV-2 and IFV-A. In addition, while the penetration stage of HSV-2 was also significantly suppressed with ASWPH, no such effect was observed in the replication of IFV-A. These results suggest that ASWPH might be useful in the prevention of infectious diseases caused by HSV-2 as well as IFV-A.
-
Sweet, C; Bird, R A; Coates, D M; Overton, H A; Smith, H
1985-01-01
Three recent wild-type H1N1 influenza virus isolates (A/USSR/90/77, A/Fiji/15899/83 and A/Firenze/13/83) replicated poorly in organ cultures of ferret bronchial tissue compared with the replication of an H3N2 wild-type virus (A/England/939/69). All four viruses replicated well in nasal turbinate tissue. Examination of one H1N1 virus (A/USSR/90/77) in vivo showed heavy infection in the upper respiratory tract of ferrets but little in the lower respiratory tract. These results raise the possibility that the mildness of human influenza arising from the H1N1 strains may be due to lack of capacity to attack the lower respiratory tract as well as the presence of antibody in previously exposed persons.
-
Kaul, Artur; Stauffer, Sarah; Berger, Carola; Pertel, Thomas; Schmitt, Jennifer; Kallis, Stephanie; Zayas, Margarita; Lopez, Margarita Zayas; Lohmann, Volker; Luban, Jeremy; Bartenschlager, Ralf
2009-08-01
Viruses are obligate intracellular parasites and therefore their replication completely depends on host cell factors. In case of the hepatitis C virus (HCV), a positive-strand RNA virus that in the majority of infections establishes persistence, cyclophilins are considered to play an important role in RNA replication. Subsequent to the observation that cyclosporines, known to sequester cyclophilins by direct binding, profoundly block HCV replication in cultured human hepatoma cells, conflicting results were obtained as to the particular cyclophilin (Cyp) required for viral RNA replication and the underlying possible mode of action. By using a set of cell lines with stable knock-down of CypA or CypB, we demonstrate in the present work that replication of subgenomic HCV replicons of different genotypes is reduced by CypA depletion up to 1,000-fold whereas knock-down of CypB had no effect. Inhibition of replication was rescued by over-expression of wild type CypA, but not by a mutant lacking isomerase activity. Replication of JFH1-derived full length genomes was even more sensitive to CypA depletion as compared to subgenomic replicons and virus production was completely blocked. These results argue that CypA may target an additional viral factor outside of the minimal replicase contributing to RNA amplification and assembly, presumably nonstructural protein 2. By selecting for resistance against the cyclosporine analogue DEBIO-025 that targets CypA in a dose-dependent manner, we identified two mutations (V2440A and V2440L) close to the cleavage site between nonstructural protein 5A and the RNA-dependent RNA polymerase in nonstructural protein 5B that slow down cleavage kinetics at this site and reduce CypA dependence of viral replication. Further amino acid substitutions at the same cleavage site accelerating processing increase CypA dependence. Our results thus identify an unexpected correlation between HCV polyprotein processing and CypA dependence of HCV replication.
-
Replication of tobacco mosaic virus RNA.
Buck, K W
1999-01-01
The replication of tobacco mosaic virus (TMV) RNA involves synthesis of a negative-strand RNA using the genomic positive-strand RNA as a template, followed by the synthesis of positive-strand RNA on the negative-strand RNA templates. Intermediates of replication isolated from infected cells include completely double-stranded RNA (replicative form) and partly double-stranded and partly single-stranded RNA (replicative intermediate), but it is not known whether these structures are double-stranded or largely single-stranded in vivo. The synthesis of negative strands ceases before that of positive strands, and positive and negative strands may be synthesized by two different polymerases. The genomic-length negative strand also serves as a template for the synthesis of subgenomic mRNAs for the virus movement and coat proteins. Both the virus-encoded 126-kDa protein, which has amino-acid sequence motifs typical of methyltransferases and helicases, and the 183-kDa protein, which has additional motifs characteristic of RNA-dependent RNA polymerases, are required for efficient TMV RNA replication. Purified TMV RNA polymerase also contains a host protein serologically related to the RNA-binding subunit of the yeast translational initiation factor, eIF3. Study of Arabidopsis mutants defective in RNA replication indicates that at least two host proteins are needed for TMV RNA replication. The tomato resistance gene Tm-1 may also encode a mutant form of a host protein component of the TMV replicase. TMV replicase complexes are located on the endoplasmic reticulum in close association with the cytoskeleton in cytoplasmic bodies called viroplasms, which mature to produce 'X bodies'. Viroplasms are sites of both RNA replication and protein synthesis, and may provide compartments in which the various stages of the virus mutiplication cycle (protein synthesis, RNA replication, virus movement, encapsidation) are localized and coordinated. Membranes may also be important for the configuration of the replicase with respect to initiation of RNA synthesis, and synthesis and release of progeny single-stranded RNA. PMID:10212941
-
Abdulhaqq, Shaheed A; Martinez, Melween I; Kang, Guobin; Foulkes, Andrea S; Rodriguez, Idia V; Nichols, Stephanie M; Hunter, Meredith; Sariol, Carlos A; Ruiz, Lynnette A; Ross, Brian N; Yin, Xiangfan; Speicher, David W; Haase, Ashley T; Marx, Preston A; Li, Qinsheng; Kraiselburd, Edmundo N; Montaner, Luis J
2014-04-01
Intravaginal exposure to simian immunodeficiency virus (SIV) acutely recruits interferon-alpha (IFN-α) producing plasmacytoid dendritic cells (pDC) and CD4 T-lymphocyte targets to the endocervix of nonhuman primates. We tested the impact of repeated cervicovaginal exposures to noninfectious, defective SIV particles over 72 hours on a subsequent cervicovaginal challenge with replication competent SIV. Thirty-four female Indian Rhesus macaques were given a 3-day twice-daily vaginal exposures to either SIVsmB7, a replication-deficient derivative of SIVsmH3 produced by a T lymphoblast CEMx174 cell clone (n = 16), or to CEM supernatant controls (n = 18). On the fourth day, animals were either euthanized to assess cervicovaginal immune cell infiltration or intravaginally challenged with SIVmac251. Challenged animals were tracked for plasma viral load and CD4 counts and euthanized at 42 days after infection. At the time of challenge, macaques exposed to SIVsmB7, had higher levels of cervical CD123 pDCs (P = 0.032) and CD4 T cells (P = 0.036) than those exposed to CEM control. Vaginal tissues showed a significant increase in CD4 T-cell infiltrates (P = 0.048) and a trend toward increased CD68 cellular infiltrates. After challenge, 12 SIVsmB7-treated macaques showed 2.5-fold greater daily rate of CD4 decline (P = 0.0408), and viral load rise (P = 0.0036) as compared with 12 control animals. Repeated nonproductive exposure to viral particles within a short daily time frame did not protect against infection despite pDC recruitment, resulting instead in an accelerated CD4 T-cell loss with an increased rate of viral replication.
-
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mangel, Wally
2008-10-15
Vaccines are effective against viruses such as polio and measles, but vaccines against other important viruses, such as HIV and flu viruses, may be impossible to obtain. These viruses change their genetic makeup each time they replicate so that the immune system cannot recognize all their variations. Hence it is important to develop new antiviral agents that inhibit virus replication. During this lecture, Dr. Mangel will discuss his group's work with a model system, the human adenovirus, which causes, among other ailments, pink eye, blindness and obesity. Mangel's team has developed a promising drug candidate that works by inihibiting adenovirusmore » proteinase, an enzyme necessary for viral replication.« less
-
Viral subversion of host functions for picornavirus translation and RNA replication
Chase, Amanda J; Semler, Bert L
2012-01-01
Picornavirus infections lead to symptoms that can have serious health and economic implications. The viruses in this family (Picornaviridae) have a small genomic RNA and must rely on host proteins for efficient viral gene expression and RNA replication. To ensure their effectiveness as pathogens, picornaviruses have evolved to utilize and/or alter host proteins for the benefit of the virus life cycle. This review discusses the host proteins that are subverted during infection to aid in virus replication. It will also describe proteins and functions that are altered during infection for the benefit of the virus. PMID:23293659
-
Postdoctoral Fellow | Center for Cancer Research
A postdoctoral position is available in the Viral Recombination Section (VRS), HIV Dynamics and Replication Program, CCR. The VRS studies retroviral replication using human immunodeficiency viruses and other retroviruses, with a particular emphasis on the mechanisms of viral RNA biology, specific RNA packaging, virus assembly, and HIV replication. Molecular tools and
-
Banga, Riddhima; Procopio, Francesco A.; Ruggiero, Alessandra; Noto, Alessandra; Ohmiti, Khalid; Cavassini, Matthias; Corpataux, Jean-Marc; Paxton, William A.; Pollakis, Georgios; Perreau, Matthieu
2018-01-01
We recently demonstrated that lymph nodes (LNs) PD-1+/T follicular helper (Tfh) cells from antiretroviral therapy (ART)-treated HIV-infected individuals were enriched in cells containing replication competent virus. However, the distribution of cells containing inducible replication competent virus has been only partially elucidated in blood memory CD4 T-cell populations including the Tfh cell counterpart circulating in blood (cTfh). In this context, we have investigated the distribution of (1) total HIV-infected cells and (2) cells containing replication competent and infectious virus within various blood and LN memory CD4 T-cell populations of conventional antiretroviral therapy (cART)-treated HIV-infected individuals. In the present study, we show that blood CXCR3-expressing memory CD4 T cells are enriched in cells containing inducible replication competent virus and contributed the most to the total pool of cells containing replication competent and infectious virus in blood. Interestingly, subsequent proviral sequence analysis did not indicate virus compartmentalization between blood and LN CD4 T-cell populations, suggesting dynamic interchanges between the two compartments. We then investigated whether the composition of blood HIV reservoir may reflect the polarization of LN CD4 T cells at the time of reservoir seeding and showed that LN PD-1+ CD4 T cells of viremic untreated HIV-infected individuals expressed significantly higher levels of CXCR3 as compared to CCR4 and/or CCR6, suggesting that blood CXCR3-expressing CD4 T cells may originate from LN PD-1+ CD4 T cells. Taken together, these results indicate that blood CXCR3-expressing CD4 T cells represent the major blood compartment containing inducible replication competent virus in treated aviremic HIV-infected individuals. PMID:29459864
-
Banga, Riddhima; Procopio, Francesco A; Ruggiero, Alessandra; Noto, Alessandra; Ohmiti, Khalid; Cavassini, Matthias; Corpataux, Jean-Marc; Paxton, William A; Pollakis, Georgios; Perreau, Matthieu
2018-01-01
We recently demonstrated that lymph nodes (LNs) PD-1 + /T follicular helper (Tfh) cells from antiretroviral therapy (ART)-treated HIV-infected individuals were enriched in cells containing replication competent virus. However, the distribution of cells containing inducible replication competent virus has been only partially elucidated in blood memory CD4 T-cell populations including the Tfh cell counterpart circulating in blood (cTfh). In this context, we have investigated the distribution of (1) total HIV-infected cells and (2) cells containing replication competent and infectious virus within various blood and LN memory CD4 T-cell populations of conventional antiretroviral therapy (cART)-treated HIV-infected individuals. In the present study, we show that blood CXCR3-expressing memory CD4 T cells are enriched in cells containing inducible replication competent virus and contributed the most to the total pool of cells containing replication competent and infectious virus in blood. Interestingly, subsequent proviral sequence analysis did not indicate virus compartmentalization between blood and LN CD4 T-cell populations, suggesting dynamic interchanges between the two compartments. We then investigated whether the composition of blood HIV reservoir may reflect the polarization of LN CD4 T cells at the time of reservoir seeding and showed that LN PD-1 + CD4 T cells of viremic untreated HIV-infected individuals expressed significantly higher levels of CXCR3 as compared to CCR4 and/or CCR6, suggesting that blood CXCR3-expressing CD4 T cells may originate from LN PD-1 + CD4 T cells. Taken together, these results indicate that blood CXCR3-expressing CD4 T cells represent the major blood compartment containing inducible replication competent virus in treated aviremic HIV-infected individuals.
-
Hanson, Laura K.; Slater, Jacquelyn S.; Karabekian, Zaruhi; Virgin, Herbert W.; Biron, Christine A.; Ruzek, Melanie C.; van Rooijen, Nico; Ciavarra, Richard P.; Stenberg, Richard M.; Campbell, Ann E.
1999-01-01
Blood monocytes or tissue macrophages play a pivotal role in the pathogenesis of murine cytomegalovirus (MCMV) infection, providing functions beneficial to both the virus and the host. In vitro and in vivo studies have indicated that differentiated macrophages support MCMV replication, are target cells for MCMV infection within tissues, and harbor latent MCMV DNA. However, this cell type presumably initiates early, antiviral immune responses as well. In addressing this paradoxical role of macrophages, we provide evidence that the proficiency of MCMV replication in macrophages positively correlates with virulence in vivo. An MCMV mutant from which the open reading frames M139, M140, and M141 had been deleted (RV10) was defective in its ability to replicate in macrophages in vitro and was highly attenuated for growth in vivo. However, depletion of splenic macrophages significantly enhanced, rather than deterred, replication of both wild-type (WT) virus and RV10 in the spleen. The ability of RV10 to replicate in intact or macrophage-depleted spleens was independent of cytokine production, as this mutant virus was a poor inducer of cytokines compared to WT virus in both intact organs and macrophage-depleted organs. Macrophages were, however, a major contributor to the production of tumor necrosis factor alpha and gamma interferon in response to WT virus infection. Thus, the data indicate that tissue macrophages serve a net protective role and may function as “filters” in protecting other highly permissive cell types from MCMV infection. The magnitude of virus replication in tissue macrophages may dictate the amount of virus accessible to the other cells. Concomitantly, infection of this cell type initiates the production of antiviral immune responses to guarantee efficient clearance of acute MCMV infection. PMID:10364349
-
Konduru, Krishnamurthy; Bradfute, Steven B.; Jacques, Jerome; Manangeeswaran, Mohanraj; Nakamura, Siham; Morshed, Sufi; Wood, Steven C.; Bavari, Sina
2011-01-01
Ebola virus is a Filoviridae that causes hemorrhagic fever in humans and induces high morbidity and mortality rates. Filoviruses are classified as "Category A bioterrorism agents", and currently there are no licensed therapeutics or vaccines to treat and prevent infection. The Filovirus glycoprotein (GP) is sufficient to protect individuals against infection, and several vaccines based on GP are under development including recombinant adenovirus, parainfluenza virus, Venezuelan equine encephalitis virus, vesicular stomatitis virus (VSV) and virus-like particles. Here we describe the development of a GP Fc fusion protein as a vaccine candidate. We expressed the extracellular domain of the Zaire Ebola virus (ZEBOV) GP fused to the Fc fragment of human IgG1 (ZEBOVGP-Fc) in mammalian cells and showed that GP undergoes the complex furin cleavage and processing observed in the native membrane-bound GP. Mice immunized with ZEBOVGP-Fc developed T-cell immunity against ZEBOV GP and neutralizing antibodies against replication-competent VSV-G deleted recombinant VSV containing ZEBOV GP. The ZEBOVGP-Fc vaccinated mice were protected against challenge with a lethal dose of ZEBOV. These results show that vaccination with the ZEBOVGP-Fc fusion protein alone without the need of a viral vector or assembly into virus-like particles is sufficient to induce protective immunity against ZEBOV in mice. Our data suggested that Filovirus GP Fc fusion proteins could be developed as a simple, safe, efficacious, and cost effective vaccine against Filovirus infection for human use. PMID:21329775
-
Pappas, Claudia; Aguilar, Patricia V.; Basler, Christopher F.; Solórzano, Alicia; Zeng, Hui; Perrone, Lucy A.; Palese, Peter; García-Sastre, Adolfo; Katz, Jacqueline M.; Tumpey, Terrence M.
2008-01-01
The 1918 influenza pandemic was exceptionally severe, resulting in the death of up to 50 million people worldwide. Here, we show which virus genes contributed to the replication and virulence of the 1918 influenza virus. Recombinant viruses, in which genes of the 1918 virus were replaced with genes from a contemporary human H1N1 influenza virus, A/Texas/36/91 (Tx/91), were generated. The exchange of most 1918 influenza virus genes with seasonal influenza H1N1 virus genes did not alter the virulence of the 1918 virus; however, substitution of the hemagglutinin (HA), neuraminidase (NA), or polymerase subunit PB1 genes significantly affected the ability of this virus to cause severe disease in mice. The 1918 virus virulence observed in mice correlated with the ability of 1918 recombinant viruses to replicate efficiently in human airway cells. In a second series of experiments, eight 1918 1:7 recombinants were generated, in which each Tx/91 virus gene was individually replaced by a corresponding gene from 1918 virus. Replication capacity of the individual 1:7 reassortant viruses was assessed in mouse lungs and human airway cells. Increased virus titers were observed among 1:7 viruses containing individual 1918 HA, NA, and PB1 genes. In addition, the 1918 PB1:Tx/91 (1:7) virus showed a distinctly larger plaque size phenotype than the small plaque phenotype of the 1918 PA:Tx/91 and 1918 PB2:Tx/91 1:7 reassortants. These results highlight the importance of the 1918 HA, NA, and PB1 genes for optimal virus replication and virulence of this pandemic strain. PMID:18287069
-
Truyen, U; Parrish, C R
1992-01-01
Canine parvovirus (CPV) emerged as an apparently new virus during the mid-1970s. The origin of CPV is unknown, but a variation from feline panleukopenia virus (FPV) or another closely related parvovirus is suspected. Here we examine the in vitro and in vivo canine and feline host ranges of CPV and FPV. Examination of three canine and six feline cell lines and mitogen-stimulated canine and feline peripheral blood lymphocytes revealed that CPV replicates in both canine and feline cells, whereas FPV replicates efficiently only in feline cells. The in vivo host ranges were unexpectedly complex and distinct from the in vitro host ranges. Inoculation of dogs with FPV revealed efficient replication in the thymus and, to some degree, in the bone marrow, as shown by virus isolation, viral DNA recovery, and Southern blotting and by strand-specific in situ hybridization. FPV replication could not be demonstrated in mesenteric lymph nodes or in the small intestine, which are important target tissues in CPV infection. Although CPV replicated well in all the feline cells tested in vitro, it did not replicate in any tissue of cats after intramuscular or intravenous inoculation. These results indicate that these viruses have complex and overlapping host ranges and that distinct tissue tropisms exist in the homologous and heterologous hosts. Images PMID:1323703
-
Fernández-Alarcón, Claudia; Hernandez-Alvarado, Nelmary; Zabeli, Jason C.; Janus, Bradley C.; Putri, Dira S.; Schleiss, Mark R.
2017-01-01
Primary Zika virus (ZIKV) infections that occur during pregnancy can cause spontaneous abortion and profoundly disrupt fetal development. While the full range of developmental abnormalities associated with congenital Zika syndrome is not yet known, severe cases of the syndrome can present with microcephaly, extensive neurologic and ocular damage, and pronounced joint malformations. Animal models that accurately recapitulate congenital Zika syndrome are urgently needed for vaccine development and for the study of ZIKV pathogenesis. As guinea pigs have successfully been used to model transplacental infections by cytomegalovirus, syphilis, and Listeria monocytogenes, we sought to test whether ZIKV could productively infect guinea pigs and whether viral transmission with attendant fetal pathology would occur after a mid-gestation viral challenge. We found that guinea pig cells supported ZIKV replication in vitro. Experimental infection of non-pregnant animals did not result in overt disease but low-level, detectable viremia was observed. When pregnant guinea pigs were challenged with ZIKV at between 18 and 21 days gestational age, ZIKV was not detected in maternal or pup blood, plasma, or tissues and no significant differences in maternal weight gain or pup size were observed following challenge. Nonetheless, a robust antibody response against ZIKV was detected in both the pups and dams. These results suggest that, while guinea pigs can model aspects of the immune response to ZIKV infection during pregnancy, naturally circulating ZIKV strains are not pathogenic during the pregnancy of immunocompetent guinea pigs and do not interfere with normal pup development. PMID:29099873
-
Sutton, Troy C.; Lamirande, Elaine W.; Czako, Rita
2017-01-01
ABSTRACT The recent outbreak of avian origin H10N7 influenza among seals in northern Europe and two fatal human infections with an avian H10N8 virus in China have demonstrated that H10 viruses can spread between mammals and cause severe disease in humans. To gain insight into the potential for H10 viruses to cross the species barrier and to identify a candidate vaccine strain, we evaluated the in vitro and in vivo properties and antibody response in ferrets to 20 diverse H10 viruses. H10 virus infection of ferrets caused variable weight loss, and all 20 viruses replicated throughout the respiratory tract; however, replication in the lungs was highly variable. In glycan-binding assays, the H10 viruses preferentially bound “avian-like” α2,3-linked sialic acids. Importantly, several isolates also displayed strong binding to long-chain “human-like” α2,6-linked sialic acids and exhibited comparable or elevated neuraminidase activity relative to human H1N1, H2N2, and H3N2 viruses. In hemagglutination inhibition assays, 12 antisera cross-reacted with ≥14 of 20 H10 viruses, and 7 viruses induced neutralizing activity against ≥15 of the 20 viruses. By combining data on weight loss, viral replication, and the cross-reactive antibody response, we identified A/mallard/Portugal/79906/2009 (H10N7) as a suitable virus for vaccine development. Collectively, our findings suggest that H10 viruses may continue to sporadically infect humans and other mammals, underscoring the importance of developing an H10 vaccine for pandemic preparedness. IMPORTANCE Avian origin H10 influenza viruses sporadically infect humans and other mammals; however, little is known about viruses of this subtype. Thus, we characterized the biological properties of 20 H10 viruses in vitro and in ferrets. Infection caused mild to moderate weight loss (5 to 15%), with robust viral replication in the nasal tissues and variable replication in the lung. H10 viruses preferentially bind “avian-like” sialic acids, although several isolates also displayed binding to “human-like” sialic acid receptors. This is consistent with the ability of H10 viruses to cross the species barrier and warrants selection of an H10 vaccine strain. By evaluating the cross-reactive antibody response to the H10 viruses and combining this analysis with viral replication and weight loss findings, we identified A/mallard/Portugal/79906/2009 (H10N7) as a suitable H10 vaccine strain. PMID:28701401
-
Genescà, Meritxell; Ma, Zhong-Min; Wang, Yichuan; Assaf, Basel; Qureshi, Huma; Fritts, Linda; Huang, Ying; McChesney, Michael B.
2012-01-01
Immunization with attenuated lentiviruses is the only reliable method of protecting rhesus macaques (RM) from vaginal challenge with pathogenic simian immunodeficiency virus (SIV). CD8+ lymphocyte depletion prior to SIVmac239 vaginal challenge demonstrated that a modest, Gag-specific CD8+ T cell response induced by immunization with simian-human immunodeficiency virus 89.6 (SHIV89.6) protects RM. Although CD8+ T cells are required for protection, there is no anamnestic expansion of SIV-specific CD8+ T cells in any tissues except the vagina after challenge. Further, SHIV immunization increased the number of viral target cells in the vagina and cervix, suggesting that the ratio of target cells to antiviral CD8+ T cells was not a determinant of protection. We hypothesized that persistent replication of the attenuated vaccine virus modulates inflammatory responses and limits T cell activation and expansion by inducing immunoregulatory T cell populations. We found that attenuated SHIV infection decreased the number of circulating plasmacytoid dendritic cells, suppressed T cell activation, decreased mRNA levels of proinflammatory mediators, and increased mRNA levels of immunoregulatory molecules. Three days after SIV vaginal challenge, SHIV-immunized RM had significantly more T regulatory cells in the vagina than the unimmunized RM. By day 14 postchallenge, immune activation and inflammation were characteristic of unimmunized RM but were minimal in SHIV-immunized RM. Thus, a modest vaccine-induced CD8+ T cell response in the context of immunoregulatory suppression of T cell activation may protect against vaginal HIV transmission. PMID:22696662
-
Lorenzo, Gema; Rodríguez-Pulido, Miguel; López-Gil, Elena; Sobrino, Francisco; Borrego, Belén; Sáiz, Margarita; Brun, Alejandro
2014-09-01
In this work we have addressed the effect of synthetic, non-infectious, RNA transcripts, mimicking structural domains of the non-coding regions (NCRs) of the foot-and-mouth disease virus (FMDV) genome on the infection of mice with Rift Valley fever virus (RVFV). Groups of 5 mice were inoculated intraperitoneally (i.p.) with 200 μg of synthetic RNA resembling the 5'-terminal S region, the internal ribosome entry site (IRES) or the 3'-NCR of the FMDV genome. RNA inoculation was performed 24h before (-24 h), 24 h after (+24 h) or simultaneously to the challenge with a lethal dose of RVFV. Administration of the IRES RNA afforded higher survival rates than administration of S or 3'NCR transcripts either at -24h or +24h after challenge. In contrast, when RNA inoculation and viral challenge were performed simultaneously, all mice survived in both IRES- and 3'NCR-inoculated groups, with an 80% survival in mice receiving the S RNA. Among survivors, a complete correlation between significant anti-RVFV circulating antibody titers and resistance to a second lethal challenge with the virus was observed, supporting a limited viral replication in the RNA-inoculated animals upon the first challenge. All three RNA transcripts were able to induce the production of systemic antiviral and pro-inflammatory cytokines. These data show that triggering of intracellular pathogen sensing pathways constitutes a promising approach towards development of novel RVF preventive or therapeutic strategies. Copyright © 2014 Elsevier B.V. All rights reserved.
-
Activation of DNA damage repair pathways by murine polyomavirus.
Heiser, Katie; Nicholas, Catherine; Garcea, Robert L
2016-10-01
Nuclear replication of DNA viruses activates DNA damage repair (DDR) pathways, which are thought to detect and inhibit viral replication. However, many DNA viruses also depend on these pathways in order to optimally replicate their genomes. We investigated the relationship between murine polyomavirus (MuPyV) and components of DDR signaling pathways including CHK1, CHK2, H2AX, ATR, and DNAPK. We found that recruitment and retention of DDR proteins at viral replication centers was independent of H2AX, as well as the viral small and middle T-antigens. Additionally, infectious virus production required ATR kinase activity, but was independent of CHK1, CHK2, or DNAPK signaling. ATR inhibition did not reduce the total amount of viral DNA accumulated, but affected the amount of virus produced, indicating a defect in virus assembly. These results suggest that MuPyV may utilize a subset of DDR proteins or non-canonical DDR signaling pathways in order to efficiently replicate and assemble. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.
-
Le Boeuf, Fabrice; Lemay, Chantal; De Silva, Naomi; Diallo, Jean-Simon; Cox, Julie; Becker, Michelle; Choi, Youngmin; Ananth, Abhirami; Sellers, Clara; Breton, Sophie; Roy, Dominic; Falls, Theresa; Brun, Jan; Hemminki, Akseli; Hinkkanen, Ari; Bell, John C.
2013-01-01
Attenuated Semliki Forest virus (SFV) may be suitable for targeting malignant glioma due to its natural neurotropism, but its replication in brain tumor cells may be restricted by innate antiviral defenses. We attempted to facilitate SFV replication in glioma cells by combining it with vaccinia virus, which is capable of antagonizing such defenses. Surprisingly, we found parenchymal mouse brain tumors to be refractory to both viruses. Also, vaccinia virus appears to be sensitive to SFV-induced antiviral interference. PMID:23221568
-
Aagaard, Lars; Mikkelsen, Jacob Giehm; Warming, Søren; Duch, Mogens; Pedersen, Finn Skou
2002-02-01
To study the replication of murine leukaemia viruses in human cells we have used full-length as well as EGFP-tagged ecotropic viruses in combination with mCAT-1-expressing human cells. We present results showing that N-tropic murine leukaemia viruses are restricted in both infection and replication in such cells while B-tropic viruses, modified at capsid position 110, escape restriction. These results support a recently reported Fv1-like restriction in mammalian cells. We extend the analysis of Fv1-like restriction by demonstrating that NB-tropic viruses also escape restriction and human mCAT-1-expressing cells are thus similar to murine Fv1(b) cells with respect to infection though the ecotropic receptor pathway.
-
Munir, Shirin; Amaro-Carambot, Emerito; Surman, Sonja; Mackow, Natalie; Yang, Lijuan; Buchholz, Ursula J.; Collins, Peter L.; Schaap-Nutt, Anne
2014-01-01
ABSTRACT A recombinant chimeric bovine/human parainfluenza type 3 virus (rB/HPIV3) vector expressing the respiratory syncytial virus (RSV) fusion F glycoprotein previously exhibited disappointing levels of RSV F immunogenicity and genetic stability in children (D. Bernstein et al., Pediatr. Infect. Dis. J. 31:109–114, 2012; C.-F. Yang et al., Vaccine 31:2822–2827, 2013). To investigate parameters that might affect vaccine performance and stability, we constructed and characterized rB/HPIV3 viruses expressing RSV F from the first (pre-N), second (N-P), third (P-M), and sixth (HN-L) genome positions. There was a 30- to 69-fold gradient in RSV F expression from the first to the sixth position. The inserts moderately attenuated vector replication in vitro and in the upper and lower respiratory tracts of hamsters: this was not influenced by the level of RSV F expression and syncytium formation. Surprisingly, inserts in the second, third, and sixth positions conferred increased temperature sensitivity: this was greatest for the third position and was the most attenuating in vivo. Each rB/HPIV3 vector induced a high titer of neutralizing antibodies in hamsters against RSV and HPIV3. Protection against RSV challenge was greater for position 2 than for position 6. Evaluation of insert stability suggested that RSV F is under selective pressure to be silenced during vector replication in vivo, but this was not exacerbated by a high level of RSV F expression and generally involved a small percentage of recovered vector. Vector passaged in vitro accumulated mutations in the HN open reading frame, causing a dramatic increase in plaque size that may have implications for vaccine production and immunogenicity. IMPORTANCE The research findings presented here will be instrumental for improving the design of a bivalent pediatric vaccine for respiratory syncytial virus and parainfluenza virus type 3, two major causes of severe respiratory tract infection in infants and young children. Moreover, this knowledge has general application to the development and clinical evaluation of other mononegavirus vectors and vaccines. PMID:24478424
-
Shaw, George M.; Hunter, Eric
2012-01-01
HIV-1 is transmitted by sexual contact across mucosal surfaces, by maternal-infant exposure, and by percutaneous inoculation. For reasons that are still incompletely understood, CCR5-tropic viruses (R5 viruses) are preferentially transmitted by all routes. Transmission is followed by an orderly appearance of viral and host markers of infection in the blood plasma. In the acute phase of infection, HIV-1 replicates exponentially and diversifies randomly, allowing for an unambiguous molecular identification of transmitted/founder virus genomes and a precise characterization of the population bottleneck to virus transmission. Sexual transmission of HIV-1 most often results in productive clinical infection arising from a single virus, highlighting the extreme bottleneck and inherent inefficiency in virus transmission. It remains to be determined if HIV-1 transmission is largely a stochastic process whereby any reasonably fit R5 virus can be transmitted or if there are features of transmitted/founder viruses that facilitate their transmission in a biologically meaningful way. Human tissue explant models of HIV-1 infection and animal models of SIV/SHIV/HIV-1 transmission, coupled with new challenge virus strains that more closely reflect transmitted/founder viruses, have the potential to elucidate fundamental mechanisms in HIV-1 transmission relevant to vaccine design and other prevention strategies. PMID:23043157
-
Ling, Binhua; Rogers, Linda; Johnson, Ann-Marie; Piatak, Michael; Lifson, Jeffrey; Veazey, Ronald S
2013-11-01
Definitive treatment of HIV infection remains a critical but elusive goal, with persistence of residual virus even in the face of prolonged administration of suppressive combination antiretroviral treatment (cART) providing a source for recrudescent infection if treatment is stopped. Characterization of the residual virus and devising strategies to target it for eradication are key goals in HIV treatment research. Indian rhesus macaques (In-RM) infected with SIVmac have been widely used in such research. However, it has proven challenging to achieve and sustain clinically relevant levels of suppression (<30 vRNA copies/ml plasma) with cART in such models. As ease of viral suppression by cART is related to pretreatment levels of viral replication, and levels of replication of SIVmac239/251 are lower in Chinese rhesus macaques (Ch-RM) than in In-RM, we evaluated cART administration to SIVmac-infected Ch-RM as a potential model for studies of residual virus and eradication strategies. Four SIVmac239-infected Ch-RM received cART including reverse transcriptase inhibitors PMPA/FTC and integrase inhibitor L-870812 daily for 8 weeks. Plasma viral loads were promptly reduced to <30 copies/ml upon initiation of cART. Cell-associated SIV DNA levels in lymphocytes from the gut were also significantly reduced. Jejunal and colonic CCR5(+)CD4(+) mucosal memory T cells increased significantly; restoration of these cells was associated with reductions in immune activation. In conclusion, cART effectively suppressed viral replication to <30 vRNA copies/ml in SIVmac239-infected Ch-RM, reducing immune activation and restoring mucosal immune cell populations. SIVmac239-infected Ch-RM may be a useful model for studying responses to cART and persistent tissue reservoirs and evaluating candidate eradication strategies to cure HIV infection.
-
Khalil, Mohamed I; Sommer, Marvin H; Hay, John; Ruyechan, William T; Arvin, Ann M
2015-07-01
The VZV genome has two origins of DNA replication (oriS), each of which consists of an AT-rich sequence and three origin binding protein (OBP) sites called Box A, C and B. In these experiments, the mutation in the core sequence CGC of the Box A and C not only inhibited DNA replication but also inhibited both ORF62 and ORF63 expression in reporter gene assays. In contrast the Box B mutation did not influence DNA replication or flanking gene transcription. These results suggest that efficient DNA replication enhances ORF62 and ORF63 transcription. Recombinant viruses carrying these mutations in both sites and one with a deletion of the whole oriS were constructed. Surprisingly, the recombinant virus lacking both copies of oriS retained the capacity to replicate in melanoma and HELF cells suggesting that VZV has another origin of DNA replication. Copyright © 2015 Elsevier Inc. All rights reserved.
-
Gasper, David J.; Neldner, Brandon; Plisch, Erin H.; Rustom, Hani; Imai, Hirotaka; Kawaoka, Yoshihiro; Suresh, M.
2016-01-01
CD8+ cytotoxic T lymphocytes (CTLs) are critical for clearing many viral infections, and protective CTL memory can be induced by vaccination with attenuated viruses and vectors. Non-replicating vaccines are typically potentiated by the addition of adjuvants that enhance humoral responses, however few are capable of generating CTL responses. Adjuplex is a carbomer-lecithin-based adjuvant demonstrated to elicit robust humoral immunity to non-replicating antigens. We report that mice immunized with non-replicating Adjuplex-adjuvanted vaccines generated robust antigen-specific CTL responses. Vaccination by the subcutaneous or the intranasal route stimulated systemic and mucosal CTL memory respectively. However, only CTL memory induced by intranasal vaccination was protective against influenza viral challenge, and correlated with an enhancement of memory CTLs in the airways and CD103+ CD69+ CXCR3+ resident memory-like CTLs in the lungs. Mechanistically, Myd88-deficient mice mounted primary CTL responses to Adjuplex vaccines that were similar in magnitude to wild-type mice, but exhibited altered differentiation of effector cell subsets. Immune potentiating effects of Adjuplex entailed alterations in the frequency of antigen-presenting-cell subsets in vaccine draining lymph nodes, and in the lungs and airways following intranasal vaccination. Further, Adjuplex enhanced the ability of dendritic cells to promote antigen-induced proliferation of naïve CD8 T cells by modulating antigen uptake, its intracellular localization, and rate of processing. Taken together, we have identified an adjuvant that elicits both systemic and mucosal CTL memory to non-replicating antigens, and engenders protective CTL-based heterosubtypic immunity to influenza A virus in the respiratory tract. Further, findings presented in this manuscript have provided key insights into the mechanisms and factors that govern the induction and programming of systemic and protective memory CTLs in the respiratory tract. PMID:27997610
-
Gasper, David J; Neldner, Brandon; Plisch, Erin H; Rustom, Hani; Carrow, Emily; Imai, Hirotaka; Kawaoka, Yoshihiro; Suresh, M
2016-12-01
CD8+ cytotoxic T lymphocytes (CTLs) are critical for clearing many viral infections, and protective CTL memory can be induced by vaccination with attenuated viruses and vectors. Non-replicating vaccines are typically potentiated by the addition of adjuvants that enhance humoral responses, however few are capable of generating CTL responses. Adjuplex is a carbomer-lecithin-based adjuvant demonstrated to elicit robust humoral immunity to non-replicating antigens. We report that mice immunized with non-replicating Adjuplex-adjuvanted vaccines generated robust antigen-specific CTL responses. Vaccination by the subcutaneous or the intranasal route stimulated systemic and mucosal CTL memory respectively. However, only CTL memory induced by intranasal vaccination was protective against influenza viral challenge, and correlated with an enhancement of memory CTLs in the airways and CD103+ CD69+ CXCR3+ resident memory-like CTLs in the lungs. Mechanistically, Myd88-deficient mice mounted primary CTL responses to Adjuplex vaccines that were similar in magnitude to wild-type mice, but exhibited altered differentiation of effector cell subsets. Immune potentiating effects of Adjuplex entailed alterations in the frequency of antigen-presenting-cell subsets in vaccine draining lymph nodes, and in the lungs and airways following intranasal vaccination. Further, Adjuplex enhanced the ability of dendritic cells to promote antigen-induced proliferation of naïve CD8 T cells by modulating antigen uptake, its intracellular localization, and rate of processing. Taken together, we have identified an adjuvant that elicits both systemic and mucosal CTL memory to non-replicating antigens, and engenders protective CTL-based heterosubtypic immunity to influenza A virus in the respiratory tract. Further, findings presented in this manuscript have provided key insights into the mechanisms and factors that govern the induction and programming of systemic and protective memory CTLs in the respiratory tract.
-
Audigé, Annette; Hofer, Ursula; Dittmer, Ulf; van den Broek, Maries; Speck, Roberto F
2011-10-01
Existing therapies for chronic viral infections are still suboptimal or have considerable side effects, so new therapeutic strategies need to be developed. One option is to boost the host's immune response with cytokines. We have recently shown in an acute ex vivo HIV infection model that co-administration of interferon (IFN)-α and interleukin (IL)-7 allows us to combine the potent anti-HIV activity of IFN-α with the beneficial effects of IL-7 on T-cell survival and function. Here we evaluated the effect of combining IFN-α and IL-7 on viral replication in vivo in the chronic lymphocytic choriomeningitis virus (LCMV) and acute Friend retrovirus (FV) infection models. In the chronic LCMV model, cytokine treatment was started during the early replication phase (i.e., on day 7 post-infection [pi]). Under the experimental conditions used, exogenous IFN-α inhibited FV replication, but had no effect on viral replication in the LCMV model. There was no therapeutic benefit of IL-7 either alone or in combination with IFN-α in either of the two infection models. In the LCMV model, dose-dependent effects of the cytokine combination on T-cell phenotype/function were observed. It is possible that these effects would translate into antiviral activity in re-challenged mice. It is also possible that another type of IFN-α/β or induction of endogenous IFN-α/β alone or in combination with IL-7 would have antiviral activity in the LCMV model. Furthermore, we cannot exclude that some effect on viral titers would have been seen at later time points not investigated here (i.e., beyond day 34 pi). Finally, IFN-α/IL-7 may inhibit the replication of other viruses. Thus it might be worth testing these cytokines in other in vivo models of chronic viral infections.
-
Mann, Alex J; Noulin, Nicolas; Catchpole, Andrew; Stittelaar, Koert J; de Waal, Leon; Veldhuis Kroeze, Edwin J B; Hinchcliffe, Michael; Smith, Alan; Montomoli, Emanuele; Piccirella, Simona; Osterhaus, Albert D M E; Knight, Alastair; Oxford, John S; Lapini, Giulia; Cox, Rebecca; Lambkin-Williams, Rob
2014-01-01
We investigated the protective efficacy of two intranasal chitosan (CSN and TM-CSN) adjuvanted H5N1 Influenza vaccines against highly pathogenic avian Influenza (HPAI) intratracheal and intranasal challenge in a ferret model. Six groups of 6 ferrets were intranasally vaccinated twice, 21 days apart, with either placebo, antigen alone, CSN adjuvanted antigen, or TM-CSN adjuvanted antigen. Homologous and intra-subtypic antibody cross-reacting responses were assessed. Ferrets were inoculated intratracheally (all treatments) or intranasally (CSN adjuvanted and placebo treatments only) with clade 1 HPAI A/Vietnam/1194/2004 (H5N1) virus 28 days after the second vaccination and subsequently monitored for morbidity and mortality outcomes. Clinical signs were assessed and nasal as well as throat swabs were taken daily for virology. Samples of lung tissue, nasal turbinates, brain, and olfactory bulb were analysed for the presence of virus and examined for histolopathological findings. In contrast to animals vaccinated with antigen alone, the CSN and TM-CSN adjuvanted vaccines induced high levels of antibodies, protected ferrets from death, reduced viral replication and abrogated disease after intratracheal challenge, and in the case of CSN after intranasal challenge. In particular, the TM-CSN adjuvanted vaccine was highly effective at eliciting protective immunity from intratracheal challenge; serologically, protective titres were demonstrable after one vaccination. The 2-dose schedule with TM-CSN vaccine also induced cross-reactive antibodies to clade 2.1 and 2.2 H5N1 viruses. Furthermore ferrets immunised with TM-CSN had no detectable virus in the respiratory tract or brain, whereas there were signs of virus in the throat and lungs, albeit at significantly reduced levels, in CSN vaccinated animals. This study demonstrated for the first time that CSN and in particular TM-CSN adjuvanted intranasal vaccines have the potential to protect against significant mortality and morbidity arising from infection with HPAI H5N1 virus.
-
Cyclophilin B is a functional regulator of hepatitis C virus RNA polymerase.
Watashi, Koichi; Ishii, Naoto; Hijikata, Makoto; Inoue, Daisuke; Murata, Takayuki; Miyanari, Yusuke; Shimotohno, Kunitada
2005-07-01
Viruses depend on host-derived factors for their efficient genome replication. Here, we demonstrate that a cellular peptidyl-prolyl cis-trans isomerase (PPIase), cyclophilin B (CyPB), is critical for the efficient replication of the hepatitis C virus (HCV) genome. CyPB interacted with the HCV RNA polymerase NS5B to directly stimulate its RNA binding activity. Both the RNA interference (RNAi)-mediated reduction of endogenous CyPB expression and the induced loss of NS5B binding to CyPB decreased the levels of HCV replication. Thus, CyPB functions as a stimulatory regulator of NS5B in HCV replication machinery. This regulation mechanism for viral replication identifies CyPB as a target for antiviral therapeutic strategies.
-
Genome-wide RNAi Screening to Identify Host Factors That Modulate Oncolytic Virus Therapy.
Allan, Kristina J; Mahoney, Douglas J; Baird, Stephen D; Lefebvre, Charles A; Stojdl, David F
2018-04-03
High-throughput genome-wide RNAi (RNA interference) screening technology has been widely used for discovering host factors that impact virus replication. Here we present the application of this technology to uncovering host targets that specifically modulate the replication of Maraba virus, an oncolytic rhabdovirus, and vaccinia virus with the goal of enhancing therapy. While the protocol has been tested for use with oncolytic Maraba virus and oncolytic vaccinia virus, this approach is applicable to other oncolytic viruses and can also be utilized for identifying host targets that modulate virus replication in mammalian cells in general. This protocol describes the development and validation of an assay for high-throughput RNAi screening in mammalian cells, the key considerations and preparation steps important for conducting a primary high-throughput RNAi screen, and a step-by-step guide for conducting a primary high-throughput RNAi screen; in addition, it broadly outlines the methods for conducting secondary screen validation and tertiary validation studies. The benefit of high-throughput RNAi screening is that it allows one to catalogue, in an extensive and unbiased fashion, host factors that modulate any aspect of virus replication for which one can develop an in vitro assay such as infectivity, burst size, and cytotoxicity. It has the power to uncover biotherapeutic targets unforeseen based on current knowledge.
-
Long, Kelly R; Lomonosova, Elena; Li, Qilan; Ponzar, Nathan L; Villa, Juan A; Touchette, Erin; Rapp, Stephen; Liley, R Matt; Murelli, Ryan P; Grigoryan, Alexandre; Buller, R Mark; Wilson, Lisa; Bial, John; Sagartz, John E; Tavis, John E
2018-01-01
Chronic hepatitis B virus infection cannot be cured by current therapies, so new treatments are urgently needed. We recently identified novel inhibitors of the hepatitis B virus ribonuclease H that suppress viral replication in cell culture. Here, we employed immunodeficient FRG KO mice whose livers had been engrafted with primary human hepatocytes to ask whether ribonuclease H inhibitors can suppress hepatitis B virus replication in vivo. Humanized FRG KO mice infected with hepatitis B virus were treated for two weeks with the ribonuclease H inhibitors #110, an α-hydroxytropolone, and #208, an N-hydroxypyridinedione. Hepatitis B virus viral titers and S and e antigen plasma levels were measured. Treatment with #110 and #208 caused significant reductions in plasma viremia without affecting hepatitis B virus S or e antigen levels, and viral titers rebounded following treatment cessation. This is the expected pattern for inhibitors of viral DNA synthesis. Compound #208 suppressed viral titers of both hepatitis B virus genotype A and C isolates. These data indicate that Hepatitis B virus replication can be suppressed during infection in an animal by inhibiting the viral ribonuclease H, validating the ribonuclease H as a novel target for antiviral drug development. Copyright © 2017 Elsevier B.V. All rights reserved.
-
Clinical development of Ebola vaccines
Sridhar, Saranya
2015-01-01
The ongoing outbreak of Ebola virus disease in West Africa highlighted the lack of a licensed drug or vaccine to combat the disease and has renewed the urgency to develop a pipeline of Ebola vaccines. A number of different vaccine platforms are being developed by assessing preclinical efficacy in animal models and expediting clinical development. Over 15 different vaccines are in preclinical development and 8 vaccines are now in different stages of clinical evaluation. These vaccines include DNA vaccines, virus-like particles and viral vectors such as live replicating vesicular stomatitis virus (rVSV), human and chimpanzee adenovirus, and vaccinia virus. Recently, in preliminary results reported from the first phase III trial of an Ebola vaccine, the rVSV-vectored vaccine showed promising efficacy. This review charts this rapidly advancing area of research focusing on vaccines in clinical development and discusses the future opportunities and challenges faced in the licensure and deployment of Ebola vaccines. PMID:26668751
-
Mowshowitz, S L; Deval, J
1980-01-01
The replication of influenza B/Lee/40 virus in MDCK (canine kidney) cells was sensitive to alpha-amanitin and actinomycin D. In vitro, virion transcriptase activity was stimulated by dinucleotide primers such as ApG. The above characteristics are shared by A/WSN virus.
-
Activation of DNA damage repair pathways by murine polyomavirus
DOE Office of Scientific and Technical Information (OSTI.GOV)
Heiser, Katie; Nicholas, Catherine; Garcea, Robert
Nuclear replication of DNA viruses activates DNA damage repair (DDR) pathways, which are thought to detect and inhibit viral replication. However, many DNA viruses also depend on these pathways in order to optimally replicate their genomes. We investigated the relationship between murine polyomavirus (MuPyV) and components of DDR signaling pathways including CHK1, CHK2, H2AX, ATR, and DNAPK. We found that recruitment and retention of DDR proteins at viral replication centers was independent of H2AX, as well as the viral small and middle T-antigens. Additionally, infectious virus production required ATR kinase activity, but was independent of CHK1, CHK2, or DNAPK signaling.more » ATR inhibition did not reduce the total amount of viral DNA accumulated, but affected the amount of virus produced, indicating a defect in virus assembly. These results suggest that MuPyV may utilize a subset of DDR proteins or non-canonical DDR signaling pathways in order to efficiently replicate and assemble. -- Highlights: •Murine polyomavirus activates and recruits DNA damage repair (DDR) proteins to replication centers. •Large T-antigen mediates recruitment of DDR proteins to viral replication centers. •Inhibition or knockout of CHK1, CHK2, DNA-PK or H2AX do not affect viral titers. •Inhibition of ATR activity reduces viral titers, but not viral DNA accumulation.« less
-
Kuo, Shu-Ming; Chen, Chi-Jene; Chang, Shih-Cheng; Liu, Tzu-Jou; Chen, Yi-Hsiang; Huang, Sheng-Yu; Shih, Shin-Ru
2017-06-13
Avian influenza A viruses generally do not replicate efficiently in human cells, but substitution of glutamic acid (Glu, E) for lysine (Lys, K) at residue 627 of avian influenza virus polymerase basic protein 2 (PB2) can serve to overcome host restriction and facilitate human infectivity. Although PB2 residue 627 is regarded as a species-specific signature of influenza A viruses, host restriction factors associated with PB2 627 E have yet to be fully investigated. We conducted immunoprecipitation, followed by differential proteomic analysis, to identify proteins associating with PB2 627 K (human signature) and PB2 627 E (avian signature) of influenza A/WSN/1933(H1N1) virus, and the results indicated that Tu elongation factor, mitochondrial (TUFM), had a higher binding affinity for PB2 627 E than PB2 627 K in transfected human cells. Stronger binding of TUFM to avian-signature PB2 590 G/ 591 Q and PB2 627 E in the 2009 swine-origin pandemic H1N1 and 2013 avian-origin H7N9 influenza A viruses was similarly observed. Viruses carrying avian-signature PB2 627 E demonstrated increased replication in TUFM-deficient cells, but viral replication decreased in cells overexpressing TUFM. Interestingly, the presence of TUFM specifically inhibited the replication of PB2 627 E viruses, but not PB2 627 K viruses. In addition, enhanced levels of interaction between TUFM and PB2 627 E were noted in the mitochondrial fraction of infected cells. Furthermore, TUFM-dependent autophagy was reduced in TUFM-deficient cells infected with PB2 627 E virus; however, autophagy remained consistent in PB2 627 K virus-infected cells. The results suggest that TUFM acts as a host restriction factor that impedes avian-signature influenza A virus replication in human cells in a manner that correlates with autophagy. IMPORTANCE An understanding of the mechanisms that influenza A viruses utilize to shift host tropism and the identification of host restriction factors that can limit infection are both critical to the prevention and control of emerging viruses that cross species barriers to target new hosts. Using a proteomic approach, we revealed a novel role for TUFM as a host restriction factor that exerts an inhibitory effect on avian-signature PB2 627 E influenza virus propagation in human cells. We further found that increased TUFM-dependent autophagy correlates with the inhibitory effect on avian-signature influenza virus replication and may serve as a key intrinsic mechanism to restrict avian influenza virus infection in humans. These findings provide new insight regarding the TUFM mitochondrial protein and may have important implications for the development of novel antiviral strategies. Copyright © 2017 Kuo et al.
-
Gao, Pei; Xiang, Bin; Li, Yulian; Li, Yaling; Sun, Minhua; Kang, Yinfeng; Xie, Peng; Chen, Libin; Lin, Qiuyan; Liao, Ming; Ren, Tao
2018-04-01
The antiviral cytokine interferon-alpha (IFN-α) plays a critical role in the innate immune system. Previous studies have shown that recombinant chicken IFN-α inhibits avian influenza virus (AIV) replication in vivo; however, the antiviral effect of recombinant duck IFN-α (rDuIFN-α) on highly pathogenic AIV remains unknown. In this study, the duck IFN-α gene was cloned, expressed, and purified. The antiviral effects of the resulting rDuIFN-α were further evaluated in vitro and in vivo. Our results showed that rDuIFN-α inhibited the replication of vesicular stomatitis virus (VSV) and AIV in duck embryo fibroblasts in vitro, with antiviral activities against VSV and AIV of 2.1 × 10 5 and 4.1 × 10 5 U/mg, respectively. We next investigated the anti-H5N1 AIV effect of intramuscular injection of rDuIFN-α in vivo. rDuIFN-α reduced viral titers in the brains, lungs, and spleens of 2-day-old (2D) ducks compared with that in the virus-challenged control group, and pretreatment with rDuIFN-α reduced mortality from 60% to 10% in 2D ducks. Moreover, rDuIFN-α increased the expression of IFN-stimulated genes in the brains and spleens of 2D ducks. Our results demonstrate that rDuIFN-α blocks VSV and H5N1 influenza virus infection in vitro and exhibits antiviral effects against H5N1 influenza virus infection in 2D ducks.
-
Chotiwan, Nunya; Andre, Barbara G; Sanchez-Vargas, Irma; Islam, M Nurul; Grabowski, Jeffrey M; Hopf-Jannasch, Amber; Gough, Erik; Nakayasu, Ernesto; Blair, Carol D; Belisle, John T; Hill, Catherine A; Kuhn, Richard J; Perera, Rushika
2018-02-01
We describe the first comprehensive analysis of the midgut metabolome of Aedes aegypti, the primary mosquito vector for arboviruses such as dengue, Zika, chikungunya and yellow fever viruses. Transmission of these viruses depends on their ability to infect, replicate and disseminate from several tissues in the mosquito vector. The metabolic environments within these tissues play crucial roles in these processes. Since these viruses are enveloped, viral replication, assembly and release occur on cellular membranes primed through the manipulation of host metabolism. Interference with this virus infection-induced metabolic environment is detrimental to viral replication in human and mosquito cell culture models. Here we present the first insight into the metabolic environment induced during arbovirus replication in Aedes aegypti. Using high-resolution mass spectrometry, we have analyzed the temporal metabolic perturbations that occur following dengue virus infection of the midgut tissue. This is the primary site of infection and replication, preceding systemic viral dissemination and transmission. We identified metabolites that exhibited a dynamic-profile across early-, mid- and late-infection time points. We observed a marked increase in the lipid content. An increase in glycerophospholipids, sphingolipids and fatty acyls was coincident with the kinetics of viral replication. Elevation of glycerolipid levels suggested a diversion of resources during infection from energy storage to synthetic pathways. Elevated levels of acyl-carnitines were observed, signaling disruptions in mitochondrial function and possible diversion of energy production. A central hub in the sphingolipid pathway that influenced dihydroceramide to ceramide ratios was identified as critical for the virus life cycle. This study also resulted in the first reconstruction of the sphingolipid pathway in Aedes aegypti. Given conservation in the replication mechanisms of several flaviviruses transmitted by this vector, our results highlight biochemical choke points that could be targeted to disrupt transmission of multiple pathogens by these mosquitoes.
-
Chotiwan, Nunya; Andre, Barbara G.; Sanchez-Vargas, Irma; Islam, M. Nurul; Grabowski, Jeffrey M.; Hopf-Jannasch, Amber; Gough, Erik; Nakayasu, Ernesto; Blair, Carol D.; Hill, Catherine A.; Kuhn, Richard J.
2018-01-01
We describe the first comprehensive analysis of the midgut metabolome of Aedes aegypti, the primary mosquito vector for arboviruses such as dengue, Zika, chikungunya and yellow fever viruses. Transmission of these viruses depends on their ability to infect, replicate and disseminate from several tissues in the mosquito vector. The metabolic environments within these tissues play crucial roles in these processes. Since these viruses are enveloped, viral replication, assembly and release occur on cellular membranes primed through the manipulation of host metabolism. Interference with this virus infection-induced metabolic environment is detrimental to viral replication in human and mosquito cell culture models. Here we present the first insight into the metabolic environment induced during arbovirus replication in Aedes aegypti. Using high-resolution mass spectrometry, we have analyzed the temporal metabolic perturbations that occur following dengue virus infection of the midgut tissue. This is the primary site of infection and replication, preceding systemic viral dissemination and transmission. We identified metabolites that exhibited a dynamic-profile across early-, mid- and late-infection time points. We observed a marked increase in the lipid content. An increase in glycerophospholipids, sphingolipids and fatty acyls was coincident with the kinetics of viral replication. Elevation of glycerolipid levels suggested a diversion of resources during infection from energy storage to synthetic pathways. Elevated levels of acyl-carnitines were observed, signaling disruptions in mitochondrial function and possible diversion of energy production. A central hub in the sphingolipid pathway that influenced dihydroceramide to ceramide ratios was identified as critical for the virus life cycle. This study also resulted in the first reconstruction of the sphingolipid pathway in Aedes aegypti. Given conservation in the replication mechanisms of several flaviviruses transmitted by this vector, our results highlight biochemical choke points that could be targeted to disrupt transmission of multiple pathogens by these mosquitoes. PMID:29447265
-
The IFITMs Inhibit Zika Virus Replication.
Savidis, George; Perreira, Jill M; Portmann, Jocelyn M; Meraner, Paul; Guo, Zhiru; Green, Sharone; Brass, Abraham L
2016-06-14
Zika virus has emerged as a severe health threat with a rapidly expanding range. The IFITM family of restriction factors inhibits the replication of a broad range of viruses, including the closely related flaviruses West Nile virus and dengue virus. Here, we show that IFITM1 and IFITM3 inhibit Zika virus infection early in the viral life cycle. Moreover, IFITM3 can prevent Zika-virus-induced cell death. These results suggest that strategies to boost the actions and/or levels of the IFITMs might be useful for inhibiting a broad range of emerging viruses. Copyright © 2016. Published by Elsevier Inc.
-
Engineering Temperature Sensitive Live Attenuated Influenza Vaccines from Emerging Viruses
Zhou, Bin; Li, Yan; Speer, Scott D.; Subba, Anju; Lin, Xudong; Wentworth, David E.
2012-01-01
The licensed live attenuated influenza A vaccine (LAIV) in the United States is created by making a reassortant containing six internal genes from a cold-adapted master donor strain (ca A/AA/6/60) and two surface glycoprotein genes from a circulating/emerging strain (e.g., A/CA/7/09 for the 2009/2010 H1N1 pandemic). Technologies to rapidly create recombinant viruses directly from patient specimens were used to engineer alternative LAIV candidates that have genomes composed entirely of vRNAs from pandemic or seasonal strains. Multiple mutations involved in the temperature-sensitive (ts) phenotype of the ca A/AA/6/60 master donor strain were introduced into a 2009 H1N1 pandemic strain rA/New York/1682/2009 (rNY1682-WT) to create rNY1682-TS1, and additional mutations identified in other ts viruses were added to rNY1682-TS1 to create rNY1682-TS2. Both rNY1682-TS1 and rNY1682-TS2 replicated efficiently at 30°C and 33°C. However, rNY1682-TS1 was partially restricted, and rNY1682-TS2 was completely restricted at 39°C. Additionally, engineering the TS1 or TS2 mutations into a distantly related human seasonal H1N1 influenza A virus also resulted pronounced restriction of replication in vitro. Clinical symptoms and virus replication in the lungs of mice showed that although rNY1682-TS2 and the licensed FluMist®-H1N1pdm LAIV that was used to combat the 2009/2010 pandemic were similarly attenuated, the rNY1682-TS2 was more protective upon challenge with a virulent mutant of pandemic H1N1 virus or a heterologous H1N1 (A/PR/8/1934) virus. This study demonstrates that engineering key temperature sensitive mutations (PB1-K391E, D581G, A661T; PB2-P112S, N265S, N556D, Y658H) into the genomes of influenza A viruses attenuates divergent human virus lineages and provides an alternative strategy for the generation of LAIVs. PMID:22449422
-
Prasanth, K. Reddisiva; Barajas, Daniel
2014-01-01
ABSTRACT RNA viruses co-opt a large number of cellular proteins that affect virus replication and, in some cases, viral genetic recombination. RNA recombination helps viruses in an evolutionary arms race with the host's antiviral responses and adaptation of viruses to new hosts. Tombusviruses and a yeast model host are used to identify cellular factors affecting RNA virus replication and RNA recombination. In this study, we have examined the role of the conserved Rpn11p metalloprotease subunit of the proteasome, which couples deubiquitination and degradation of proteasome substrates, in tombusvirus replication and recombination in Saccharomyces cerevisiae and plants. Depletion or mutations of Rpn11p lead to the rapid formation of viral RNA recombinants in combination with reduced levels of viral RNA replication in yeast or in vitro based on cell extracts. Rpn11p interacts with the viral replication proteins and is recruited to the viral replicase complex (VRC). Analysis of the multifunctional Rpn11p has revealed that the primary role of Rpn11p is to act as a “matchmaker” that brings the viral p92pol replication protein and the DDX3-like Ded1p/RH20 DEAD box helicases into VRCs. Overexpression of Ded1p can complement the defect observed in rpn11 mutant yeast by reducing TBSV recombination. This suggests that Rpn11p can suppress tombusvirus recombination via facilitating the recruitment of the cellular Ded1p helicase, which is a strong suppressor of viral recombination, into VRCs. Overall, this work demonstrates that the co-opted Rpn11p, which is involved in the assembly of the functional proteasome, also functions in the proper assembly of the tombusvirus VRCs. IMPORTANCE RNA viruses evolve rapidly due to genetic changes based on mutations and RNA recombination. Viral genetic recombination helps viruses in an evolutionary arms race with the host's antiviral responses and facilitates adaptation of viruses to new hosts. Cellular factors affect viral RNA recombination, although the role of the host in virus evolution is still understudied. In this study, we used a plant RNA virus, tombusvirus, to examine the role of a cellular proteasomal protein, called Rpn11, in tombusvirus recombination in a yeast model host, in plants, and in vitro. We found that the cellular Rpn11 is subverted for tombusvirus replication and Rpn11 has a proteasome-independent function in facilitating viral replication. When the Rpn11 level is knocked down or a mutated Rpn11 is expressed, then tombusvirus RNA goes through rapid viral recombination and evolution. Taken together, the results show that the co-opted cellular Rpn11 is a critical host factor for tombusviruses by regulating viral replication and genetic recombination. PMID:25540361
-
Naidoo, Vanessa L.; Mann, Jaclyn K.; Noble, Christie; Adland, Emily; Carlson, Jonathan M.; Thomas, Jake; Brumme, Chanson J.; Thobakgale-Tshabalala, Christina F.; Brumme, Zabrina L.; Goulder, Philip J. R.
2017-01-01
ABSTRACT In the large majority of cases, HIV infection is established by a single variant, and understanding the characteristics of successfully transmitted variants is relevant to prevention strategies. Few studies have investigated the viral determinants of mother-to-child transmission. To determine the impact of Gag-protease-driven viral replication capacity on mother-to-child transmission, the replication capacities of 148 recombinant viruses encoding plasma-derived Gag-protease from 53 nontransmitter mothers, 48 transmitter mothers, and 47 infected infants were assayed in an HIV-1-inducible green fluorescent protein reporter cell line. All study participants were infected with HIV-1 subtype C. There was no significant difference in replication capacities between the nontransmitter (n = 53) and transmitter (n = 44) mothers (P = 0.48). Infant-derived Gag-protease NL4-3 recombinant viruses (n = 41) were found to have a significantly lower Gag-protease-driven replication capacity than that of viruses derived from the mothers (P < 0.0001 by a paired t test). High percent similarities to consensus subtype C Gag, p17, p24, and protease sequences were also found in the infants (n = 28) in comparison to their mothers (P = 0.07, P = 0.002, P = 0.03, and P = 0.02, respectively, as determined by a paired t test). These data suggest that of the viral quasispecies found in mothers, the HIV mother-to-child transmission bottleneck favors the transmission of consensus-like viruses with lower viral replication capacities. IMPORTANCE Understanding the characteristics of successfully transmitted HIV variants has important implications for preventative interventions. Little is known about the viral determinants of HIV mother-to-child transmission (MTCT). We addressed the role of viral replication capacity driven by Gag, a major structural protein that is a significant determinant of overall viral replicative ability and an important target of the host immune response, in the MTCT bottleneck. This study advances our understanding of the genetic bottleneck in MTCT by revealing that viruses transmitted to infants have a lower replicative ability as well as a higher similarity to the population consensus (in this case HIV subtype C) than those of their mothers. Furthermore, the observation that “consensus-like” virus sequences correspond to lower in vitro replication abilities yet appear to be preferentially transmitted suggests that viral characteristics favoring transmission are decoupled from those that enhance replicative capacity. PMID:28637761
-
Targeting Host Cell Surface Nucleolin for RSV Therapy: Challenges and Opportunities.
Mastrangelo, Peter; Norris, Michael J; Duan, Wenming; Barrett, Edward G; Moraes, Theo J; Hegele, Richard G
2017-09-19
Nucleolin (NCL) has been reported as a cellular receptor for the human respiratory syncytial virus (RSV). We studied the effects of re-purposing AS1411, an anti-cancer compound that binds cell surface NCL, as a possible novel strategy for RSV therapy in vitro and in vivo. AS1411 was administered to RSV-infected cultures of non-polarized (HEp-2) and polarized (MDCK) epithelial cells and to virus-infected mice and cotton rats. Results of in vitro experiments showed that AS1411, used in micromolar concentrations, was associated with decreases in the number of virus-positive cells. Intranasal administration of AS1411 (50 mg/kg) to RSV-infected mice and cotton rats was associated with partial reductions in lung viral titers, decreased virus-associated airway inflammation, and decreased IL-4/IFN-γ ratios when compared to untreated, infected animals. In conclusion, our findings indicate that therapeutic use of AS1411 has modest effects on RSV replication and host response. While the results underscore the challenges of targeting cell surface NCL as a potential novel strategy for RSV therapy, they also highlight the potential of cell surface NCL as a therapeutic target.
-
Johnson, P R; Olmsted, R A; Prince, G A; Murphy, B R; Alling, D W; Walsh, E E; Collins, P L
1987-01-01
The degree of antigenic relatedness between human respiratory syncytial virus (RSV) subgroups A and B was estimated from antibody responses induced in cotton rats by respiratory tract infection with RSV. Glycoprotein-specific enzyme-linked immunosorbent assays of antibody responses induced by RSV infection demonstrated that the F glycoproteins of subgroups A and B were antigenically closely related (relatedness, R approximately 50%), whereas the G glycoproteins were only distantly related (R approximately 5%). Intermediate levels of antigenic relatedness (R approximately 25%) were seen in neutralizing antibodies from cotton rats infected with RSV of the two subgroups. Immunity against the F glycoprotein of subgroup A, induced by vaccinia-A2-F, conferred a high level of protection which was of comparable magnitude against challenge by RSV of either subgroup. In comparison, immunity against the G glycoprotein of subgroup A, induced by vaccinia-A2-G, conferred less complete, but significant, protection. Importantly, in vaccinia-A2-G-immunized animals, suppression of homologous challenge virus replication was significantly greater (13-fold) than that observed for the heterologous virus. PMID:3305988
-
Identifying Early Target Cells of Nipah Virus Infection in Syrian Hamsters.
Baseler, Laura; Scott, Dana P; Saturday, Greg; Horne, Eva; Rosenke, Rebecca; Thomas, Tina; Meade-White, Kimberly; Haddock, Elaine; Feldmann, Heinz; de Wit, Emmie
2016-11-01
Nipah virus causes respiratory and neurologic disease with case fatality rates up to 100% in individual outbreaks. End stage lesions have been described in the respiratory and nervous systems, vasculature and often lymphoid organs in fatal human cases; however, the initial target organs of Nipah virus infection have not been identified. Here, we detected the initial target tissues and cells of Nipah virus and tracked virus dissemination during the early phase of infection in Syrian hamsters inoculated with a Nipah virus isolate from Malaysia (NiV-M) or Bangladesh (NiV-B). Syrian hamsters were euthanized between 4 and 48 hours post intranasal inoculation and tissues were collected and analyzed for the presence of viral RNA, viral antigen and infectious virus. Virus replication was first detected at 8 hours post inoculation (hpi). Nipah virus initially targeted type I pneumocytes, bronchiolar respiratory epithelium and alveolar macrophages in the lung and respiratory and olfactory epithelium lining the nasal turbinates. By 16 hpi, virus disseminated to epithelial cells lining the larynx and trachea. Although the pattern of viral dissemination was similar for both virus isolates, the rate of spread was slower for NiV-B. Infectious virus was not detected in the nervous system or blood and widespread vascular infection and lesions within lymphoid organs were not observed, even at 48 hpi. Nipah virus initially targets the respiratory system. Virus replication in the brain and infection of blood vessels in non-respiratory tissues does not occur during the early phase of infection. However, virus replicates early in olfactory epithelium and may serve as the first step towards nervous system dissemination, suggesting that development of vaccines that block virus dissemination or treatments that can access the brain and spinal cord and directly inhibit virus replication may be necessary for preventing central nervous system pathology.
-
Possible Increased Pathogenicity of Pandemic (H1N1) 2009 Influenza Virus upon Reassortment
Schrauwen, Eefje J.A.; Herfst, Sander; Chutinimitkul, Salin; Bestebroer, Theo M.; Rimmelzwaan, Guus F.; Osterhaus, Albert D.M.E.; Kuiken, Thijs
2011-01-01
Since emergence of the pandemic (H1N1) 2009 virus in April 2009, three influenza A viruses—seasonal (H3N2), seasonal (H1N1), and pandemic (H1N1) 2009—have circulated in humans. Genetic reassortment between these viruses could result in enhanced pathogenicity. We compared 4 reassortant viruses with favorable in vitro replication properties with the wild-type pandemic (H1N1) 2009 virus with respect to replication kinetics in vitro and pathogenicity and transmission in ferrets. Pandemic (H1N1) 2009 viruses containing basic polymerase 2 alone or in combination with acidic polymerase of seasonal (H1N1) virus were attenuated in ferrets. In contrast, pandemic (H1N1) 2009 with neuraminidase of seasonal (H3N2) virus resulted in increased virus replication and more severe pulmonary lesions. The data show that pandemic (H1N1) 2009 virus has the potential to reassort with seasonal influenza viruses, which may result in increased pathogenicity while it maintains the capacity of transmission through aerosols or respiratory droplets. PMID:21291589
-
Diversity, Replication, Pathogenicity and Cell Biology of Crimean Congo Hemorrhagic Fever Virus
2007-10-01
Crimean Congo Hemorrhagic Fever Virus PRINCIPAL INVESTIGATOR: Adolfo García-Sastre, Ph.D. CONTRACTING...Diversity, Replication, Pathogenicity and Cell Biology of Crimean Congo Hemorrhagic Fever Virus 5b. GRANT NUMBER W81XWH-04-1-0876 5c. PROGRAM ELEMENT...localization and antigenic characterization of Crimean - Congo hemorrhagic fever virus glycoproteins. J.Virol. 79: 6152-61. Ahmed, A., McFalls,
-
O'Donnell, Christopher D; Vogel, Leatrice; Matsuoka, Yumiko; Jin, Hong; Subbarao, Kanta
2014-11-01
The threat of future influenza pandemics and their potential for rapid spread, morbidity, and mortality has led to the development of pandemic vaccines. We generated seven reassortant pandemic live attenuated influenza vaccines (pLAIVs) with the hemagglutinin (HA) and neuraminidase (NA) genes derived from animal influenza viruses on the backbone of the six internal protein gene segments of the temperature sensitive, cold-adapted (ca) A/Ann Arbor/60 (H2N2) virus (AA/60 ca) of the licensed seasonal LAIV. The pLAIV viruses were moderately to highly restricted in replication in seronegative adults; we sought to determine the biological basis for this restriction. Avian influenza viruses generally replicate at higher temperatures than human influenza viruses and, although they shared the same backbone, the pLAIV viruses had a lower shutoff temperature than seasonal LAIV viruses, suggesting that the HA and NA influence the degree of temperature sensitivity. The pH of HA activation of highly pathogenic avian influenza viruses was greater than human and low-pathogenicity avian influenza viruses, as reported by others. However, pLAIV viruses had a consistently higher pH of HA activation and reduced HA thermostability compared to the corresponding wild-type parental viruses. From studies with single-gene reassortant viruses bearing one gene segment from the AA/60 ca virus in recombinant H5N1 or pH1N1 viruses, we found that the lower HA thermal stability and increased pH of HA activation were associated with the AA/60 M gene. Together, the impaired HA acid and thermal stability and temperature sensitivity likely contributed to the restricted replication of the pLAIV viruses we observed in seronegative adults. There is increasing evidence that the HA stability of influenza viruses depends on the virus strain and host species and that HA stability can influence replication, virulence, and transmission of influenza A viruses in different species. We investigated the HA stability of pandemic live attenuated influenza vaccine (pLAIV) viruses and observed that the pLAIV viruses consistently had a less stable HA than the corresponding wild-type influenza viruses. The reduced HA stability and temperature sensitivity of the pLAIV viruses may account for their restricted replication in clinical trials. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
-
O'Donnell, Christopher D.; Vogel, Leatrice; Matsuoka, Yumiko; Jin, Hong
2014-01-01
ABSTRACT The threat of future influenza pandemics and their potential for rapid spread, morbidity, and mortality has led to the development of pandemic vaccines. We generated seven reassortant pandemic live attenuated influenza vaccines (pLAIVs) with the hemagglutinin (HA) and neuraminidase (NA) genes derived from animal influenza viruses on the backbone of the six internal protein gene segments of the temperature sensitive, cold-adapted (ca) A/Ann Arbor/60 (H2N2) virus (AA/60 ca) of the licensed seasonal LAIV. The pLAIV viruses were moderately to highly restricted in replication in seronegative adults; we sought to determine the biological basis for this restriction. Avian influenza viruses generally replicate at higher temperatures than human influenza viruses and, although they shared the same backbone, the pLAIV viruses had a lower shutoff temperature than seasonal LAIV viruses, suggesting that the HA and NA influence the degree of temperature sensitivity. The pH of HA activation of highly pathogenic avian influenza viruses was greater than human and low-pathogenicity avian influenza viruses, as reported by others. However, pLAIV viruses had a consistently higher pH of HA activation and reduced HA thermostability compared to the corresponding wild-type parental viruses. From studies with single-gene reassortant viruses bearing one gene segment from the AA/60 ca virus in recombinant H5N1 or pH1N1 viruses, we found that the lower HA thermal stability and increased pH of HA activation were associated with the AA/60 M gene. Together, the impaired HA acid and thermal stability and temperature sensitivity likely contributed to the restricted replication of the pLAIV viruses we observed in seronegative adults. IMPORTANCE There is increasing evidence that the HA stability of influenza viruses depends on the virus strain and host species and that HA stability can influence replication, virulence, and transmission of influenza A viruses in different species. We investigated the HA stability of pandemic live attenuated influenza vaccine (pLAIV) viruses and observed that the pLAIV viruses consistently had a less stable HA than the corresponding wild-type influenza viruses. The reduced HA stability and temperature sensitivity of the pLAIV viruses may account for their restricted replication in clinical trials. PMID:25122789
-
N-Myc Interactor Inhibits Prototype Foamy Virus by Sequestering Viral Tas Protein in the Cytoplasm
Hu, Xiaomei; Yang, Wei; Liu, Ruikang; Geng, Yunqi; Qiao, Wentao
2014-01-01
ABSTRACT Foamy viruses (FVs) are complex retroviruses that establish lifelong persistent infection without evident pathology. However, the roles of cellular factors in FV latency are poorly understood. This study revealed that N-Myc interactor (Nmi) could inhibit the replication of prototype foamy virus (PFV). Overexpression of Nmi reduced PFV replication, whereas its depletion by small interfering RNA increased PFV replication. The Nmi-mediated impairment of PFV replication resulted from the diminished transactivation by PFV Tas of the viral long terminal repeat (LTR) and an internal promoter (IP). Nmi was determined to interact with Tas and abrogate its function by sequestration in the cytoplasm. In addition, human and bovine Nmi proteins were found to inhibit the replication of bovine foamy virus (BFV) and PFV. Together, these results indicate that Nmi inhibits both human and bovine FVs by interfering with the transactivation function of Tas and may have a role in the host defense against FV infection. IMPORTANCE From this study, we report that the N-Myc interactor (Nmi), an interferon-induced protein, can interact with the regulatory protein Tas of the prototype foamy virus and sequester it in the cytoplasm. The results of this study suggest that Nmi plays an important role in maintaining foamy virus latency and may reveal a new pathway in the interferon-mediated antiviral barrier against viruses. These findings are important for understanding virus-host relationships not only with FVs but potentially for other retroviruses as well. PMID:24719420
-
[Research Progress on Antiviral Activity of Interferon-induced Transmembrane Proteins].
Chen, Yongkun; Zhu, Wenfei; Shu, Yuelong
2016-03-01
Interferon-induced Transmembrane Proteins (IFITMs) were identified through small interference RNA (siRNA) screening method in 1980s. The antiviral properties of the IFITMs were firstly discovered in 1996. Recently, its antiviral effect and mechanism have become a research hotspot. Many studies have shown that IFITM can inhibit the replication of multiple pathogenic viruses, including influenza A virus (IAV), Human Immunodeficiency Virus (HIV-1), hepatitis C virus (HCV), Ebola virus (EBOV), West Nile virus and so on. IFITMs inhibit the replication of virus in the early stage of the viral life cycle, which occurred before the release of viral genomes into the cytosol. Recent studies indicate that IFITM proteins could block viral replication by mediate viral membrane fusion. However, the mechanism is still under investigation. Here we review the discovery and characterization of the IFITM proteins, elucidate their antiviral activities and the potential mechanisms.
-
Sánchez-Navarro, J A; Reusken, C B; Bol, J F; Pallás, V
1997-12-01
Alfalfa mosaic virus (AMV) and Prunus necrotic ringspot virus (PNRSV) are tripartite positive-strand RNA plant viruses that encode functionally similar translation products. Although the two viruses are phylogenetically closely related, they infect a very different range of natural hosts. The coat protein (CP) gene, the movement protein (MP) gene or both genes in AMV RNA 3 were replaced by the corresponding genes of PNRSV. The chimeric viruses were tested for heterologous encapsidation, replication in protoplasts from plants transformed with AMV replicase genes P1 and P2 (P12 plants) and for cell-to-cell transport in P12 plants. The chimeric viruses exhibited basic competence for encapsidation and replication in P12 protoplasts and for a low level of cell-to-cell movement in P12 plants. The potential involvement of the MP gene in determining host specificity in ilarviruses is discussed.
-
Mink parvoviruses and interferons: in vitro studies.
Wiedbrauk, D L; Bloom, M E; Lodmell, D L
1986-01-01
Although interferons can inhibit the replication of a number of viruses, little is known about their ability to inhibit parvovirus replication. Therefore, in vitro experiments were done to determine if Aleutian disease virus and mink enteritis virus, two autonomously replicating mink parvoviruses, induced interferon, were sensitive to the effects of interferon, or inhibited the production of interferon. The results indicated that these parvoviruses neither induced nor were sensitive to the effects of interferon. Furthermore, preexisting parvovirus infections did not inhibit poly(I).poly(C)-induced interferon production. This independence from the interferon system may, therefore, be a general property of the autonomously replicating parvoviruses. PMID:2431162
-
Martínez-Solís, María; Jakubowska, Agata K; Herrero, Salvador
2017-10-01
Baculoviruses are a broad group of viruses infecting insects, predominately of the order Lepidoptera. They are used worldwide as biological insecticides and as expression vectors to produce recombinant proteins. Baculoviruses replicate in their host, although several cell lines have been developed for in vitro replication. Nevertheless, replication of baculoviruses in cell culture involves the generation of defective viruses with a decrease in productivity and virulence. Transcriptional studies of the Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) and the Autographa californica multiple nucleopolyhedrovirus (AcMNPV) infective process revealed differences in the expression patterns when the virus replicated under in vitro (Se301 cells) or in vivo (S. exigua larvae) conditions. The late expression factor 5 (lef5) gene was found to be highly overexpressed when the virus replicates in larvae. To test the possible role of lef5 expression in viral stability, recombinant AcMNPV expressing the lef5 gene from SeMNPV (Se-lef5) was generated and its stability was monitored during successive infection passages in Sf21 cells by evaluating the loss of several essential and non-essential genes. The gfp transgene was more stable in those viruses expressing the Se-LEF5 protein and the GFP-defective viruses were accumulated at a lower level when compared to its control viruses, confirming the positive influence of lef5 in viral stability during the multiplication process. This work describes for the first time a viral factor involved in transgene stability when baculoviruses replicate in cell culture, opening new ways to facilitate the in vitro production of recombinant proteins using baculovirus.
-
Gong, Xiao-Qian; Sun, Ying-Feng; Ruan, Bao-Yang; Liu, Xiao-Min; Wang, Qi; Yang, Hai-Ming; Wang, Shuai-Yong; Zhang, Peng; Wang, Xiu-Hui; Shan, Tong-Ling; Tong, Wu; Zhou, Yan-Jun; Li, Guo-Xin; Zheng, Hao; Tong, Guang-Zhi; Yu, Hai
2017-06-01
Swine influenza viruses have been circulating in pigs throughout world and might be potential threats to human health. PA-X protein is a newly discovered protein produced from the PA gene by ribosomal frameshifting and the effects of PA-X on the 1918 H1N1, the pandemic 2009 H1N1, the highly pathogenic avian H5N1 and the avian H9N2 influenza viruses have been reported. However, the role of PA-X in the pathogenesis of swine influenza virus is still unknown. In this study, we rescued the H1N1 wild-type (WT) classical swine influenza virus (A/Swine/Guangdong/1/2011 (H1N1)) and H1N1 PA-X deficient virus containing mutations at the frameshift motif, and compared their replication properties and pathogenicity of swine influenza virus in vitro and in vivo. Our results show that the expression of PA-X inhibits virus replication and polymerase activity in cultured cells and decreases virulence in mouse models. Therefore, our study demonstrates that PA-X protein acts as a negative virulence regulator for classical H1N1 swine influenza virus and decreases virulence by inhibiting viral replication and polymerase activity, deepening our understanding of the pathogenesis of swine influenza virus. Copyright © 2017 Elsevier B.V. All rights reserved.
-
Cell-Specific Establishment of Poliovirus Resistance to an Inhibitor Targeting a Cellular Protein
Viktorova, Ekaterina G.; Nchoutmboube, Jules; Ford-Siltz, Lauren A.
2015-01-01
ABSTRACT It is hypothesized that targeting stable cellular factors involved in viral replication instead of virus-specific proteins may raise the barrier for development of resistant mutants, which is especially important for highly adaptable small (+)RNA viruses. However, contrary to this assumption, the accumulated evidence shows that these viruses easily generate mutants resistant to the inhibitors of cellular proteins at least in some systems. We investigated here the development of poliovirus resistance to brefeldin A (BFA), an inhibitor of the cellular protein GBF1, a guanine nucleotide exchange factor for the small cellular GTPase Arf1. We found that while resistant viruses can be easily selected in HeLa cells, they do not emerge in Vero cells, in spite that in the absence of the drug both cultures support robust virus replication. Our data show that the viral replication is much more resilient to BFA than functioning of the cellular secretory pathway, suggesting that the role of GBF1 in the viral replication is independent of its Arf activating function. We demonstrate that the level of recruitment of GBF1 to the replication complexes limits the establishment and expression of a BFA resistance phenotype in both HeLa and Vero cells. Moreover, the BFA resistance phenotype of poliovirus mutants is also cell type dependent in different cells of human origin and results in a fitness loss in the form of reduced efficiency of RNA replication in the absence of the drug. Thus, a rational approach to the development of host-targeting antivirals may overcome the superior adaptability of (+)RNA viruses. IMPORTANCE Compared to the number of viral diseases, the number of available vaccines is miniscule. For some viruses vaccine development has not been successful after multiple attempts, and for many others vaccination is not a viable option. Antiviral drugs are needed for clinical practice and public health emergencies. However, viruses are highly adaptable and can easily generate mutants resistant to practically any compounds targeting viral proteins. An alternative approach is to target stable cellular factors recruited for the virus-specific functions. In the present study, we analyzed the factors permitting and restricting the establishment of the resistance of poliovirus, a small (+)RNA virus, to brefeldin A (BFA), a drug targeting a cellular component of the viral replication complex. We found that the emergence and replication potential of resistant mutants is cell type dependent and that BFA resistance reduces virus fitness. Our data provide a rational approach to the development of antiviral therapeutics targeting host factors. PMID:25653442
-
Autophagic machinery activated by dengue virus enhances virus replication
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lee, Y.-R.; Lei, H.-Y.; Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
2008-05-10
Autophagy is a cellular response against stresses which include the infection of viruses and bacteria. We unravel that Dengue virus-2 (DV2) can trigger autophagic process in various infected cell lines demonstrated by GFP-LC3 dot formation and increased LC3-II formation. Autophagosome formation was also observed under the transmission electron microscope. DV2-induced autophagy further enhances the titers of extracellular and intracellular viruses indicating that autophagy can promote viral replication in the infected cells. Moreover, our data show that ATG5 protein is required to execute DV2-induced autophagy. All together, we are the first to demonstrate that DV can activate autophagic machinery that ismore » favorable for viral replication.« less
-
Klingbeil, Katharina; Lange, Elke; Teifke, Jens P; Mettenleiter, Thomas C; Fuchs, Walter
2014-04-01
Pigs can be severely harmed by influenza, and represent important reservoir hosts, in which new human pathogens such as the recent pandemic swine-origin H1N1 influenza A virus can arise by mutation and reassortment of genome segments. To obtain novel, safe influenza vaccines for pigs, and to investigate the antigen-specific immune response, we modified an established live-virus vaccine against Aujeszky's disease of swine, pseudorabies virus (PrV) strain Bartha (PrV-Ba), to serve as vector for the expression of haemagglutinin (HA) of swine-origin H1N1 virus. To facilitate transgene insertion, the genome of PrV-Ba was cloned as a bacterial artificial chromosome. HA expression occurred under control of the human or murine cytomegalovirus immediate early promoters (P-HCMV, P-MCMV), but could be substantially enhanced by synthetic introns and adaptation of the codon usage to that of PrV. However, despite abundant expression, the heterologous glycoprotein was not detectably incorporated into mature PrV particles. Replication of HA-expressing PrV in cell culture was only slightly affected compared to that of the parental virus strain. A single immunization of pigs with the PrV vector expressing the codon-optimized HA gene under control of P-MCMV induced high levels of HA-specific antibodies. The vaccinated animals were protected from clinical signs after challenge with a related swine-origin H1N1 influenza A virus, and challenge virus shedding was significantly reduced.
-
Freel, Stephanie A.; Picking, Ralph A.; Ferrari, Guido; Ding, Haitao; Ochsenbauer, Christina; Kappes, John C.; Kirchherr, Jennifer L.; Soderberg, Kelly A.; Weinhold, Kent J.; Cunningham, Coleen K.; Denny, Thomas N.; Crump, John A.; Cohen, Myron S.; McMichael, Andrew J.; Haynes, Barton F.
2012-01-01
CD8-mediated virus inhibition can be detected in HIV-1-positive subjects who naturally control virus replication. Characterizing the inhibitory function of CD8+ T cells during acute HIV-1 infection (AHI) can elucidate the nature of the CD8+ responses that can be rapidly elicited and that contribute to virus control. We examined the timing and HIV-1 antigen specificity of antiviral CD8+ T cells during AHI. Autologous and heterologous CD8+ T cell antiviral functions were assessed longitudinally during AHI in five donors from the CHAVI 001 cohort using a CD8+ T cell-mediated virus inhibition assay (CD8 VIA) and transmitted/founder (T/F) viruses. Potent CD8+ antiviral responses against heterologous T/F viruses appeared during AHI at the first time point sampled in each of the 5 donors (Fiebig stages 1/2 to 5). Inhibition of an autologous T/F virus was durable to 48 weeks; however, inhibition of heterologous responses declined concurrent with the resolution of viremia. HIV-1 viruses from 6 months postinfection were more resistant to CD8+-mediated virus inhibition than cognate T/F viruses, demonstrating that the virus escapes early from CD8+ T cell-mediated inhibition of virus replication. CD8+ T cell antigen-specific subsets mediated inhibition of T/F virus replication via soluble components, and these soluble responses were stimulated by peptide pools that include epitopes that were shown to drive HIV-1 escape during AHI. These data provide insights into the mechanisms of CD8-mediated virus inhibition and suggest that functional analyses will be important for determining whether similar antigen-specific virus inhibition can be induced by T cell-directed vaccine strategies. PMID:22514337
-
Medveczky, Maria M; Sherwood, Tracy A; Klein, Thomas W; Friedman, Herman; Medveczky, Peter G
2004-09-15
The major psychoactive cannabinoid compound of marijuana, delta-9 tetrahydrocannabinol (THC), has been shown to modulate immune responses and lymphocyte function. After primary infection the viral DNA genome of gamma herpesviruses persists in lymphoid cell nuclei in a latent episomal circular form. In response to extracellular signals, the latent virus can be activated, which leads to production of infectious virus progeny. Therefore, we evaluated the potential effects of THC on gamma herpesvirus replication. Tissue cultures infected with various gamma herpesviruses were cultured in the presence of increasing concentrations of THC and the amount of viral DNA or infectious virus yield was compared to those of control cultures. The effect of THC on Kaposi's Sarcoma Associated Herpesvirus (KSHV) and Epstein-Barr virus (EBV) replication was measured by the Gardella method and replication of herpesvirus saimiri (HVS) of monkeys, murine gamma herpesvirus 68 (MHV 68), and herpes simplex type 1 (HSV-1) was measured by yield reduction assays. Inhibition of the immediate early ORF 50 gene promoter activity was measured by the dual luciferase method. Micromolar concentrations of THC inhibit KSHV and EBV reactivation in virus infected/immortalized B cells. THC also strongly inhibits lytic replication of MHV 68 and HVS in vitro. Importantly, concentrations of THC that inhibit virus replication of gamma herpesviruses have no effect on cell growth or HSV-1 replication, indicating selectivity. THC was shown to selectively inhibit the immediate early ORF 50 gene promoter of KSHV and MHV 68. THC specifically targets viral and/or cellular mechanisms required for replication and possibly shared by these gamma herpesviruses, and the endocannabinoid system is possibly involved in regulating gamma herpesvirus latency and lytic replication. The immediate early gene ORF 50 promoter activity was specifically inhibited by THC. These studies may also provide the foundation for the development of antiviral strategies utilizing non-psychoactive derivatives of THC.
-
Harmand, Thibault J; Pattabiraman, Vijaya R; Bode, Jeffrey W
2017-10-02
Interferon-induced transmembrane protein 3 (IFITM3) is an antiviral transmembrane protein that is thought to serve as the primary factor for inhibiting the replication of a large number of viruses, including West Nile virus, Dengue virus, Ebola virus, and Zika virus. Production of this 14.5 kDa, 133-residue transmembrane protein, especially with essential posttranslational modifications, by recombinant expression is challenging. In this report, we document the chemical synthesis of IFTIM3 in multi-milligram quantities (>15 mg) and the preparation of phosphorylated and fluorescent variants. The synthesis was accomplished by using KAHA ligations, which operate under acidic aqueous/organic mixtures that excel at solubilizing even the exceptionally hydrophobic C-terminal region of IFITM3. The synthetic material is readily incorporated into model vesicles and forms the basis for using synthetic, homogenous IFITM3 and its derivatives for further studying its structure and biological mode of action. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
-
Oncotargeting by Vesicular Stomatitis Virus (VSV): Advances in Cancer Therapy.
Bishnoi, Suman; Tiwari, Ritudhwaj; Gupta, Sharad; Byrareddy, Siddappa N; Nayak, Debasis
2018-02-23
Modern oncotherapy approaches are based on inducing controlled apoptosis in tumor cells. Although a number of apoptosis-induction approaches are available, site-specific delivery of therapeutic agents still remain the biggest hurdle in achieving the desired cancer treatment benefit. Additionally, systemic treatment-induced toxicity remains a major limiting factor in chemotherapy. To specifically address drug-accessibility and chemotherapy side effects, oncolytic virotherapy (OV) has emerged as a novel cancer treatment alternative. In OV, recombinant viruses with higher replication capacity and stronger lytic properties are being considered for tumor cell-targeting and subsequent cell lysing. Successful application of OVs lies in achieving strict tumor-specific tropism called oncotropism, which is contingent upon the biophysical interactions of tumor cell surface receptors with viral receptors and subsequent replication of oncolytic viruses in cancer cells. In this direction, few viral vector platforms have been developed and some of these have entered pre-clinical/clinical trials. Among these, the Vesicular stomatitis virus (VSV)-based platform shows high promise, as it is not pathogenic to humans. Further, modern molecular biology techniques such as reverse genetics tools have favorably advanced this field by creating efficient recombinant VSVs for OV; some have entered into clinical trials. In this review, we discuss the current status of VSV based oncotherapy, challenges, and future perspectives regarding its therapeutic applications in the cancer treatment.
-
Verrier, Eloi R.; Dorson, Michel; Mauger, Stéphane; Torhy, Corinne; Ciobotaru, Céline; Hervet, Caroline; Dechamp, Nicolas; Genet, Carine; Boudinot, Pierre; Quillet, Edwige
2013-01-01
Health control is a major issue in animal breeding and a better knowledge of the genetic bases of resistance to diseases is needed in farm animals including fish. The detection of quantitative trait loci (QTL) will help uncovering the genetic architecture of important traits and understanding the mechanisms involved in resistance to pathogens. We report here the detection of QTL for resistance to Viral Haemorrhagic Septicaemia Virus (VHSV), a major threat for European aquaculture industry. Two induced mitogynogenetic doubled haploid F2 rainbow trout (Oncorhynchus mykiss) families were used. These families combined the genome of susceptible and resistant F0 breeders and contained only fully homozygous individuals. For phenotyping, fish survival after an immersion challenge with the virus was recorded, as well as in vitro virus replication on fin explants. A bidirectional selective genotyping strategy identified seven QTL associated to survival. One of those QTL was significant at the genome-wide level and largely explained both survival and viral replication in fin explants in the different families of the design (up to 65% and 49% of phenotypic variance explained respectively). These results evidence the key role of innate defence in resistance to the virus and pave the way for the identification of the gene(s) responsible for resistance. The identification of a major QTL also opens appealing perspectives for selective breeding of fish with improved resistance. PMID:23390526
-
Garcia, Maricarmen; Spatz, S J; Cheng, Y; Riblet, S M; Volkening, J D; Schneiders, G H
2016-09-01
Infectious laryngotracheitis (ILT) is a highly contagious respiratory disease of chickens caused by infectious laryngotracheitis virus (ILTV). The disease is controlled by the use of live-attenuated vaccines. Previously we reported the complete nucleotide sequence of the ILTV vaccine strain (TCO) and identified a nonsense mutation in the gene encoding the ORF C protein. This suggested that the ORF C protein might be associated with viral virulence. To investigate this, an ILTV recombinant with a deletion in the gene encoding ORF C was constructed using the genome of the virulent United States Department of Agriculture (USDA) challenge strain (USDAch). Compared to the parental virus, the ΔORF C recombinant replicated in chicken kidney (CK) cells with similar kinetics and generated similar titres. This demonstrated that the ORF C deletion had no deleterious effects on replication efficacy in vitro. In chickens, the recombinant induced only minor microscopic tracheal lesions when inoculated via the intra-tracheal/ocular route, while the parental strain induced moderate to severe microscopic tracheal lesions, even though virus load in the tracheas were comparable. Groups of chickens vaccinated via eye-drop with the ∆ORFC-ILTV were protected to levels comparable to those elicited by TCO vaccination. To our knowledge, this is the first report that demonstrates the suitability of ∆ORFC as a live-attenuated vaccine to prevent the losses caused by ILTV.
-
Oncotargeting by Vesicular Stomatitis Virus (VSV): Advances in Cancer Therapy
Bishnoi, Suman; Tiwari, Ritudhwaj; Gupta, Sharad; Byrareddy, Siddappa N.; Nayak, Debasis
2018-01-01
Modern oncotherapy approaches are based on inducing controlled apoptosis in tumor cells. Although a number of apoptosis-induction approaches are available, site-specific delivery of therapeutic agents still remain the biggest hurdle in achieving the desired cancer treatment benefit. Additionally, systemic treatment-induced toxicity remains a major limiting factor in chemotherapy. To specifically address drug-accessibility and chemotherapy side effects, oncolytic virotherapy (OV) has emerged as a novel cancer treatment alternative. In OV, recombinant viruses with higher replication capacity and stronger lytic properties are being considered for tumor cell-targeting and subsequent cell lysing. Successful application of OVs lies in achieving strict tumor-specific tropism called oncotropism, which is contingent upon the biophysical interactions of tumor cell surface receptors with viral receptors and subsequent replication of oncolytic viruses in cancer cells. In this direction, few viral vector platforms have been developed and some of these have entered pre-clinical/clinical trials. Among these, the Vesicular stomatitis virus (VSV)-based platform shows high promise, as it is not pathogenic to humans. Further, modern molecular biology techniques such as reverse genetics tools have favorably advanced this field by creating efficient recombinant VSVs for OV; some have entered into clinical trials. In this review, we discuss the current status of VSV based oncotherapy, challenges, and future perspectives regarding its therapeutic applications in the cancer treatment. PMID:29473868
-
Pathogenicity Comparison Between the Kikwit and Makona Ebola Virus Variants in Rhesus Macaques.
Wong, Gary; Qiu, Xiangguo; de La Vega, Marc-Antoine; Fernando, Lisa; Wei, Haiyan; Bello, Alexander; Fausther-Bovendo, Hugues; Audet, Jonathan; Kroeker, Andrea; Kozak, Robert; Tran, Kaylie; He, Shihua; Tierney, Kevin; Soule, Geoff; Moffat, Estella; Günther, Stephan; Gao, George F; Strong, Jim; Embury-Hyatt, Carissa; Kobinger, Gary
2016-10-15
Enhanced virulence and/or transmission of West African Ebola virus (EBOV) variants, which are divergent from their Central African counterparts, are suspected to have contributed to the sizable toll of the recent Ebola virus disease (EVD) outbreak. This study evaluated the pathogenicity and shedding in rhesus macaques infected with 1 of 2 West African isolates (EBOV-C05 or EBOV-C07) or a Central African isolate (EBOV-K). All animals infected with EBOV-C05 or EBOV-C07 died of EVD, whereas 2 of 3 EBOV-K-infected animals died. The viremia level was elevated 10-fold in EBOV-C05-infected animals, compared with EBOV-C07- or EBOV-K-infected animals. More-severe lung pathology was observed in 2 of 6 EBOV-C05/C07-infected macaques. This is the first detailed analysis of the recently circulating EBOV-C05/C07 in direct comparison to EBOV-K with 6 animals per group, and it showed that EBOV-C05 but not EBOV-C07 can replicate at higher levels and cause more tissue damage in some animals. Increased virus shedding from individuals who are especially susceptible to EBOV replication is possibly one of the many challenges facing the community of healthcare and policy-making responders since the beginning of the outbreak. © Crown copyright 2016.
-
Taylor, R. Travis; Lubick, Kirk J.; Robertson, Shelly J.; Broughton, James P.; Bloom, Marshall E.; Bresnahan, Wade A.; Best, Sonja M.
2011-01-01
In response to virus infection, type I interferons (IFNs) induce several genes, most of whose functions are largely unknown. Here we show that the tripartite motif (TRIM) protein, TRIM79α, is an IFN-stimulated gene (ISG) product that specifically targets tick-borne encephalitis virus (TBEV), a Flavivirus that causes encephalitides in humans. TRIM79α restricts TBEV replication by mediating lysosome-dependent degradation of the flavivirus NS5 protein, an RNA-dependent RNA polymerase essential for virus replication. NS5 degradation was specific to tick-borne flaviviruses as TRIM79α did not recognize NS5 from West Nile virus (WNV) or inhibit WNV replication. In the absence of TRIM79α, IFN-β was less effective in inhibiting tick-borne flavivirus infection of mouse macrophages, highlighting the importance of a single virus-specific ISG in establishing an antiviral state. The specificity of TRIM79α for TBEV reveals a remarkable ability of the innate IFN response to discriminate between closely related flaviviruses. PMID:21925107
-
Distinct Contributions of Autophagy Receptors in Measles Virus Replication.
Petkova, Denitsa S; Verlhac, Pauline; Rozières, Aurore; Baguet, Joël; Claviere, Mathieu; Kretz-Remy, Carole; Mahieux, Renaud; Viret, Christophe; Faure, Mathias
2017-05-22
Autophagy is a potent cell autonomous defense mechanism that engages the lysosomal pathway to fight intracellular pathogens. Several autophagy receptors can recognize invading pathogens in order to target them towards autophagy for their degradation after the fusion of pathogen-containing autophagosomes with lysosomes. However, numerous intracellular pathogens can avoid or exploit autophagy, among which is measles virus (MeV). This virus induces a complete autophagy flux, which is required to improve viral replication. We therefore asked how measles virus interferes with autophagy receptors during the course of infection. We report that in addition to NDP52/CALCOCO₂ and OPTINEURIN/OPTN, another autophagy receptor, namely T6BP/TAXIBP1, also regulates the maturation of autophagosomes by promoting their fusion with lysosomes, independently of any infection. Surprisingly, only two of these receptors, NDP52 and T6BP, impacted measles virus replication, although independently, and possibly through physical interaction with MeV proteins. Thus, our results suggest that a restricted set of autophagosomes is selectively exploited by measles virus to replicate in the course of infection.
-
Mondal, Arindam; Potts, Gregory K.; Dawson, Anthony R.; Coon, Joshua J.; Mehle, Andrew
2015-01-01
Negative-sense RNA viruses assemble large ribonucleoprotein (RNP) complexes that direct replication and transcription of the viral genome. Influenza virus RNPs contain the polymerase, genomic RNA and multiple copies of nucleoprotein (NP). During RNP assembly, monomeric NP oligomerizes along the length of the genomic RNA. Regulated assembly of the RNP is essential for virus replication, but how NP is maintained as a monomer that subsequently oligomerizes to form RNPs is poorly understood. Here we elucidate a mechanism whereby NP phosphorylation regulates oligomerization. We identified new evolutionarily conserved phosphorylation sites on NP and demonstrated that phosphorylation of NP decreased formation of higher-order complexes. Two phosphorylation sites were located on opposite sides of the NP:NP interface. In both influenza A and B virus, mutating or mimicking phosphorylation at these residues blocked homotypic interactions and drove NP towards a monomeric form. Highlighting the central role of this process during infection, these mutations impaired RNP formation, polymerase activity and virus replication. Thus, dynamic phosphorylation of NP regulates RNP assembly and modulates progression through the viral life cycle. PMID:25867750
-
Jose, Joyce; Taylor, Aaron B; Kuhn, Richard J
2017-02-14
Sindbis virus (SINV [genus Alphavirus , family Togaviridae ]) is an enveloped, mosquito-borne virus. Alphaviruses cause cytolytic infections in mammalian cells while establishing noncytopathic, persistent infections in mosquito cells. Mosquito vector adaptation of alphaviruses is a major factor in the transmission of epidemic strains of alphaviruses. Though extensive studies have been performed on infected mammalian cells, the morphological and structural elements of alphavirus replication and assembly remain poorly understood in mosquito cells. Here we used high-resolution live-cell imaging coupled with single-particle tracking and electron microscopy analyses to delineate steps in the alphavirus life cycle in both the mammalian host cell and insect vector cells. Use of dually labeled SINV in conjunction with cellular stains enabled us to simultaneously determine the spatial and temporal differences of alphavirus replication complexes (RCs) in mammalian and insect cells. We found that the nonstructural viral proteins and viral RNA in RCs exhibit distinct spatial organization in mosquito cytopathic vacuoles compared to replication organelles from mammalian cells. We show that SINV exploits filopodial extensions for virus dissemination in both cell types. Additionally, we propose a novel mechanism for replication complex formation around glycoprotein-containing vesicles in mosquito cells that produced internally released particles that were seen budding from the vesicles by live imaging. Finally, by characterizing mosquito cell lines that were persistently infected with fluorescent virus, we show that the replication and assembly machinery are highly modified, and this allows continuous production of alphaviruses at reduced levels. IMPORTANCE Reemerging mosquito-borne alphaviruses cause serious human epidemics worldwide. Several structural and imaging studies have helped to define the life cycle of alphaviruses in mammalian cells, but the mode of virus replication and assembly in the invertebrate vector and mechanisms producing two disease outcomes in two types of cells are yet to be identified. Using transmission electron microscopy and live-cell imaging with dual fluorescent protein-tagged SINV, we show that while insect and mammalian cells display similarities in entry and exit, they present distinct spatial and temporal organizations in virus replication and assembly. By characterizing acutely and persistently infected cells, we provide new insights into alphavirus replication and assembly in two distinct hosts, resulting in high-titer virus production in mammalian cells and continuous virus production at reduced levels in mosquito cells-presumably a prerequisite for alphavirus maintenance in nature. Copyright © 2017 Jose et al.
-
Biggins, Julia E.; Biesinger, Tasha; Yu Kimata, Monica T.; Arora, Reetakshi; Kimata, Jason T.
2007-01-01
We investigated the role of ICAM-3 in DC-SIGN-mediated human immunodeficiency virus (HIV) infection of CD4+ T cells. Our results demonstrate that ICAM-3 does not appear to play a role in DC-SIGN-mediated infection of CD4+ T cells as virus is transmitted equally to ICAM-3+ or ICAM-3− Jurkat T cells. However, HIV-1 replication is enhanced in ICAM-3− cells, suggesting that ICAM-3 may limit HIV-1 replication. Similar results were obtained when SIV replication was examined in ICAM-3+ and ICAM-3− CEMx174 cells. Furthermore, while ICAM-3 has been proposed to play a co-stimulatory role in T cell activation, DC-SIGN expression on antigen presenting cells did not enhance antigen-dependent activation of T cells. Together, these data indicate that while ICAM-3 may influence HIV-1 replication, it does so independent of DC-SIGN mediated virus transmission or activation of CD4+ T cells. PMID:17434553
-
Hsu, Shih-Feng; Su, Wen-Chi; Jeng, King-Song
2015-01-01
ABSTRACT Influenza A virus (IAV) depends on cellular factors to complete its replication cycle; thus, investigation of the factors utilized by IAV may facilitate antiviral drug development. To this end, a cellular transcriptional repressor, DR1, was identified from a genome-wide RNA interference (RNAi) screen. Knockdown (KD) of DR1 resulted in reductions of viral RNA and protein production, demonstrating that DR1 acts as a positive host factor in IAV replication. Genome-wide transcriptomic analysis showed that there was a strong induction of interferon-stimulated gene (ISG) expression after prolonged DR1 KD. We found that beta interferon (IFN-β) was induced by DR1 KD, thereby activating the JAK-STAT pathway to turn on ISG expression, which led to a strong inhibition of IAV replication. This result suggests that DR1 in normal cells suppresses IFN induction, probably to prevent undesired cytokine production, but that this suppression may create a milieu that favors IAV replication once cells are infected. Furthermore, biochemical assays of viral RNA replication showed that DR1 KD suppressed viral RNA replication. We also showed that DR1 associated with all three subunits of the viral RNA-dependent RNA polymerase (RdRp) complex, indicating that DR1 may interact with individual components of the viral RdRp complex to enhance viral RNA replication. Thus, DR1 may be considered a novel host susceptibility gene for IAV replication via a dual mechanism, not only suppressing the host defense to indirectly favor IAV replication but also directly facilitating viral RNA replication. IMPORTANCE Investigations of virus-host interactions involved in influenza A virus (IAV) replication are important for understanding viral pathogenesis and host defenses, which may manipulate influenza virus infection or prevent the emergence of drug resistance caused by a high error rate during viral RNA replication. For this purpose, a cellular transcriptional repressor, DR1, was identified from a genome-wide RNAi screen as a positive regulator in IAV replication. In the current studies, we showed that DR1 suppressed the gene expression of a large set of host innate immunity genes, which indirectly facilitated IAV replication in the event of IAV infection. Besides this scenario, DR1 also directly enhanced the viral RdRp activity, likely through associating with individual components of the viral RdRp complex. Thus, DR1 represents a novel host susceptibility gene for IAV replication via multiple functions, not only suppressing the host defense but also enhancing viral RNA replication. DR1 may be a potential target for drug development against influenza virus infection. PMID:25589657
-
Unraveling the Armor of a Killer: Evasion of Host Defenses by African Swine Fever Virus.
Reis, Ana Luisa; Netherton, Chris; Dixon, Linda K
2017-03-15
African swine fever is an acute hemorrhagic disease of pigs. Extensive recent spread in the Russian Federation and Eastern Europe has increased the risk to global pig production. The virus is a large DNA virus and is the only member of the Asfarviridae family. In pigs, the virus replicates predominantly in macrophages. We review how the virus overcomes the barriers to replication in the macrophage and the virus mechanism to inhibit key host defense pathways. Copyright © 2017 American Society for Microbiology.
-
Abrao, Emiliana Pereira; da Fonseca, Benedito Antônio Lopes
2016-02-01
Dengue is one of the most important diseases caused by arboviruses in the world. Yellow fever is another arthropod-borne disease of great importance to public health that is endemic to tropical regions of Africa and the Americas. Both yellow fever and dengue viruses are flaviviruses transmitted by Aedes aegypti mosquitoes, and then, it is reasonable to consider that in a given moment, mosquito cells could be coinfected by both viruses. Therefore, we decided to evaluate if sequential infections of dengue and yellow fever viruses (and vice-versa) in mosquito cells could affect the virus replication patterns. Using immunofluorescence and real-time PCR-based replication assays in Aedes albopictus C6/36 cells with single or sequential infections with both viruses, we demonstrated the occurrence of viral interference, also called superinfection exclusion, between these two viruses. Our results show that this interference pattern is particularly evident when cells were first infected with dengue virus and subsequently with yellow fever virus (YFV). Reduction in dengue virus replication, although to a lower extent, was also observed when C6/36 cells were initially infected with YFV followed by dengue virus infection. Although the importance that these findings have on nature is unknown, this study provides evidence, at the cellular level, of the occurrence of replication interference between dengue and yellow fever viruses and raises the question if superinfection exclusion could be a possible explanation, at least partially, for the reported lack of urban yellow fever occurrence in regions where a high level of dengue transmission occurs.
-
Silva, Amanda Perse da; Lopes, Juliana Freitas; Paula, Vanessa Salete de
2014-01-01
The aim of this study was to evaluate the use of RNA interference to inhibit herpes simplex virus type-1 replication in vitro. For herpes simplex virus type-1 gene silencing, three different small interfering RNAs (siRNAs) targeting the herpes simplex virus type-1 UL39 gene (sequence si-UL 39-1, si-UL 39-2, and si-UL 39-3) were used, which encode the large subunit of ribonucleotide reductase, an essential enzyme for DNA synthesis. Herpes simplex virus type-1 was isolated from saliva samples and mucocutaneous lesions from infected patients. All mucocutaneous lesions' samples were positive for herpes simplex virus type-1 by real-time PCR and by virus isolation; all herpes simplex virus type-1 from saliva samples were positive by real-time PCR and 50% were positive by virus isolation. The levels of herpes simplex virus type-1 DNA remaining after siRNA treatment were assessed by real-time PCR, whose results demonstrated that the effect of siRNAs on gene expression depends on siRNA concentration. The three siRNA sequences used were able to inhibit viral replication, assessed by real-time PCR and plaque assays and among them, the sequence si-UL 39-1 was the most effective. This sequence inhibited 99% of herpes simplex virus type-1 replication. The results demonstrate that silencing herpes simplex virus type-1 UL39 expression by siRNAs effectively inhibits herpes simplex virus type-1 replication, suggesting that siRNA based antiviral strategy may be a potential therapeutic alternative. Copyright © 2014. Published by Elsevier Editora Ltda.
-
A virocentric perspective on the evolution of life
Koonin, Eugene V.; Dolja, Valerian V.
2015-01-01
Viruses and/or virus-like selfish elements are associated with all cellular life forms and are the most abundant biological entities on Earth, with the number of virus particles in many environments exceeding the number of cells by one to two orders of magnitude. The genetic diversity of viruses is commensurately enormous and might substantially exceed the diversity of cellular organisms. Unlike cellular organisms with their uniform replication-expression scheme, viruses possess either RNA or DNA genomes and exploit all conceivable replication-expression strategies. Although viruses extensively exchange genes with their hosts, there exists a set of viral hallmark genes that are shared by extremely diverse groups of viruses to the exclusion of cellular life forms. Coevolution of viruses and host defense systems is a key aspect in the evolution of both viruses and cells, and viral genes are often recruited for cellular functions. Together with the fundamental inevitability of the emergence of genomic parasites in any evolving replicator system, these multiple lines of evidence reveal the central role of viruses in the entire evolution of life. PMID:23850169
-
Jones, Daniel M.; Patel, Arvind H.; Targett-Adams, Paul; McLauchlan, John
2009-01-01
Studies of the hepatitis C virus (HCV) life cycle have been aided by development of in vitro systems that enable replication of viral RNA and production of infectious virus. However, the functions of the individual proteins, especially those engaged in RNA replication, remain poorly understood. It is considered that NS4B, one of the replicase components, creates sites for genome synthesis, which appear as punctate foci at the endoplasmic reticulum (ER) membrane. In this study, a panel of mutations in NS4B was generated to gain deeper insight into its functions. Our analysis identified five mutants that were incapable of supporting RNA replication, three of which had defects in production of foci at the ER membrane. These mutants also influenced posttranslational modification and intracellular mobility of another replicase protein, NS5A, suggesting that such characteristics are linked to focus formation by NS4B. From previous studies, NS4B could not be trans-complemented in replication assays. Using the mutants that blocked RNA synthesis, defective NS4B expressed from two mutants could be rescued in trans-complementation replication assays by wild-type protein produced by a functional HCV replicon. Moreover, active replication could be reconstituted by combining replicons that were defective in NS4B and NS5A. The ability to restore replication from inactive replicons has implications for our understanding of the mechanisms that direct viral RNA synthesis. Finally, one of the NS4B mutations increased the yield of infectious virus by five- to sixfold. Hence, NS4B not only functions in RNA replication but also contributes to the processes engaged in virus assembly and release. PMID:19073716
-
Cyclophilin B facilitates the replication of Orf virus.
Zhao, Kui; Li, Jida; He, Wenqi; Song, Deguang; Zhang, Ximu; Zhang, Di; Zhou, Yanlong; Gao, Feng
2017-06-15
Viruses interact with host cellular factors to construct a more favourable environment for their efficient replication. Expression of cyclophilin B (CypB), a cellular peptidyl-prolyl cis-trans isomerase (PPIase), was found to be significantly up-regulated. Recently, a number of studies have shown that CypB is important in the replication of several viruses, including Japanese encephalitis virus (JEV), hepatitis C virus (HCV) and human papillomavirus type 16 (HPV 16). However, the function of cellular CypB in ORFV replication has not yet been explored. Suppression subtractive hybridization (SSH) technique was applied to identify genes differentially expressed in the ORFV-infected MDBK cells at an early phase of infection. Cellular CypB was confirmed to be significantly up-regulated by quantitative reverse transcription-PCR (qRT-PCR) analysis and Western blotting. The role of CypB in ORFV infection was further determined using Cyclosporin A (CsA) and RNA interference (RNAi). Effect of CypB gene silencing on ORFV replication by 50% tissue culture infectious dose (TCID 50 ) assay and qRT-PCR detection. In the present study, CypB was found to be significantly up-regulated in the ORFV-infected MDBK cells at an early phase of infection. Cyclosporin A (CsA) exhibited suppressive effects on ORFV replication through the inhibition of CypB. Silencing of CypB gene inhibited the replication of ORFV in MDBK cells. In conclusion, these data suggest that CypB is critical for the efficient replication of the ORFV genome. Cellular CypB was confirmed to be significantly up-regulated in the ORFV-infected MDBK cells at an early phase of infection, which could effectively facilitate the replication of ORFV.
-
Replication and Transmission of the Novel Bovine Influenza D Virus in a Guinea Pig Model
Sreenivasan, Chithra; Thomas, Milton; Sheng, Zizhang; Hause, Ben M.; Collin, Emily A.; Knudsen, David E. B.; Pillatzki, Angela; Nelson, Eric; Wang, Dan; Kaushik, Radhey S.
2015-01-01
ABSTRACT Influenza D virus (FLUDV) is a novel influenza virus that infects cattle and swine. The goal of this study was to investigate the replication and transmission of bovine FLUDV in guinea pigs. Following direct intranasal inoculation of animals, the virus was detected in nasal washes of infected animals during the first 7 days postinfection. High viral titers were obtained from nasal turbinates and lung tissues of directly inoculated animals. Further, bovine FLUDV was able to transmit from the infected guinea pigs to sentinel animals by means of contact and not by aerosol dissemination under the experimental conditions tested in this study. Despite exhibiting no clinical signs, infected guinea pigs developed seroconversion and the viral antigen was detected in lungs of animals by immunohistochemistry. The observation that bovine FLUDV replicated in the respiratory tract of guinea pigs was similar to observations described previously in studies of gnotobiotic calves and pigs experimentally infected with bovine FLUDV but different from those described previously in experimental infections in ferrets and swine with a swine FLUDV, which supported virus replication only in the upper respiratory tract and not in the lower respiratory tract, including lung. Our study established that guinea pigs could be used as an animal model for studying this newly emerging influenza virus. IMPORTANCE Influenza D virus (FLUDV) is a novel emerging pathogen with bovine as its primary host. The epidemiology and pathogenicity of the virus are not yet known. FLUDV also spreads to swine, and the presence of FLUDV-specific antibodies in humans could indicate that there is a potential for zoonosis. Our results showed that bovine FLUDV replicated in the nasal turbinate and lungs of guinea pigs at high titers and was also able to transmit from an infected animal to sentinel animals by contact. The fact that bovine FLUDV replicated productively in both the upper and lower respiratory tracts of guinea pigs, similarly to virus infection in its native host, demonstrates that guinea pigs would be a suitable model host to study the replication and transmission potential of bovine FLUDV. PMID:26378161
-
Replication and Transmission of the Novel Bovine Influenza D Virus in a Guinea Pig Model.
Sreenivasan, Chithra; Thomas, Milton; Sheng, Zizhang; Hause, Ben M; Collin, Emily A; Knudsen, David E B; Pillatzki, Angela; Nelson, Eric; Wang, Dan; Kaushik, Radhey S; Li, Feng
2015-12-01
Influenza D virus (FLUDV) is a novel influenza virus that infects cattle and swine. The goal of this study was to investigate the replication and transmission of bovine FLUDV in guinea pigs. Following direct intranasal inoculation of animals, the virus was detected in nasal washes of infected animals during the first 7 days postinfection. High viral titers were obtained from nasal turbinates and lung tissues of directly inoculated animals. Further, bovine FLUDV was able to transmit from the infected guinea pigs to sentinel animals by means of contact and not by aerosol dissemination under the experimental conditions tested in this study. Despite exhibiting no clinical signs, infected guinea pigs developed seroconversion and the viral antigen was detected in lungs of animals by immunohistochemistry. The observation that bovine FLUDV replicated in the respiratory tract of guinea pigs was similar to observations described previously in studies of gnotobiotic calves and pigs experimentally infected with bovine FLUDV but different from those described previously in experimental infections in ferrets and swine with a swine FLUDV, which supported virus replication only in the upper respiratory tract and not in the lower respiratory tract, including lung. Our study established that guinea pigs could be used as an animal model for studying this newly emerging influenza virus. Influenza D virus (FLUDV) is a novel emerging pathogen with bovine as its primary host. The epidemiology and pathogenicity of the virus are not yet known. FLUDV also spreads to swine, and the presence of FLUDV-specific antibodies in humans could indicate that there is a potential for zoonosis. Our results showed that bovine FLUDV replicated in the nasal turbinate and lungs of guinea pigs at high titers and was also able to transmit from an infected animal to sentinel animals by contact. The fact that bovine FLUDV replicated productively in both the upper and lower respiratory tracts of guinea pigs, similarly to virus infection in its native host, demonstrates that guinea pigs would be a suitable model host to study the replication and transmission potential of bovine FLUDV. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
-
Kumar, Naveen; Barua, Sanjay; Riyesh, Thachamvally; Chaubey, Kundan K; Rawat, Krishan Dutt; Khandelwal, Nitin; Mishra, Anil K; Sharma, Nitika; Chandel, Surender S; Sharma, Shalini; Singh, Manoj K; Sharma, Dinesh K; Singh, Shoor V; Tripathi, Bhupendra N
2016-01-01
Successful purification of multiple viruses from mixed infections remains a challenge. In this study, we investigated peste des petits ruminants virus (PPRV) and foot-and-mouth disease virus (FMDV) mixed infection in goats. Rather than in a single cell type, cytopathic effect (CPE) of the virus was observed in cocultured Vero/BHK-21 cells at 6th blind passage (BP). PPRV, but not FMDV could be purified from the virus mixture by plaque assay. Viral RNA (mixture) transfection in BHK-21 cells produced FMDV but not PPRV virions, a strategy which we have successfully employed for the first time to eliminate the negative-stranded RNA virus from the virus mixture. FMDV phenotypes, such as replication competent but noncytolytic, cytolytic but defective in plaque formation and, cytolytic but defective in both plaque formation and standard FMDV genome were observed respectively, at passage level BP8, BP15 and BP19 and hence complicated virus isolation in the cell culture system. Mixed infection was not found to induce any significant antigenic and genetic diversity in both PPRV and FMDV. Further, we for the first time demonstrated the viral interference between PPRV and FMDV. Prior transfection of PPRV RNA, but not Newcastle disease virus (NDV) and rotavirus RNA resulted in reduced FMDV replication in BHK-21 cells suggesting that the PPRV RNA-induced interference was specifically directed against FMDV. On long-term coinfection of some acute pathogenic viruses (all possible combinations of PPRV, FMDV, NDV and buffalopox virus) in Vero cells, in most cases, one of the coinfecting viruses was excluded at passage level 5 suggesting that the long-term coinfection may modify viral persistence. To the best of our knowledge, this is the first documented evidence describing a natural mixed infection of FMDV and PPRV. The study not only provides simple and reliable methodologies for isolation and purification of two epidemiologically and economically important groups of viruses, but could also help in establishing better guidelines for trading animals that could transmit further infections and epidemics in disease free nations.
-
Kumar, Naveen; Barua, Sanjay; Riyesh, Thachamvally; Chaubey, Kundan K.; Rawat, Krishan Dutt; Khandelwal, Nitin; Mishra, Anil K.; Sharma, Nitika; Chandel, Surender S.; Sharma, Shalini; Singh, Manoj K.; Sharma, Dinesh K.; Singh, Shoor V.; Tripathi, Bhupendra N.
2016-01-01
Successful purification of multiple viruses from mixed infections remains a challenge. In this study, we investigated peste des petits ruminants virus (PPRV) and foot-and-mouth disease virus (FMDV) mixed infection in goats. Rather than in a single cell type, cytopathic effect (CPE) of the virus was observed in cocultured Vero/BHK-21 cells at 6th blind passage (BP). PPRV, but not FMDV could be purified from the virus mixture by plaque assay. Viral RNA (mixture) transfection in BHK-21 cells produced FMDV but not PPRV virions, a strategy which we have successfully employed for the first time to eliminate the negative-stranded RNA virus from the virus mixture. FMDV phenotypes, such as replication competent but noncytolytic, cytolytic but defective in plaque formation and, cytolytic but defective in both plaque formation and standard FMDV genome were observed respectively, at passage level BP8, BP15 and BP19 and hence complicated virus isolation in the cell culture system. Mixed infection was not found to induce any significant antigenic and genetic diversity in both PPRV and FMDV. Further, we for the first time demonstrated the viral interference between PPRV and FMDV. Prior transfection of PPRV RNA, but not Newcastle disease virus (NDV) and rotavirus RNA resulted in reduced FMDV replication in BHK-21 cells suggesting that the PPRV RNA-induced interference was specifically directed against FMDV. On long-term coinfection of some acute pathogenic viruses (all possible combinations of PPRV, FMDV, NDV and buffalopox virus) in Vero cells, in most cases, one of the coinfecting viruses was excluded at passage level 5 suggesting that the long-term coinfection may modify viral persistence. To the best of our knowledge, this is the first documented evidence describing a natural mixed infection of FMDV and PPRV. The study not only provides simple and reliable methodologies for isolation and purification of two epidemiologically and economically important groups of viruses, but could also help in establishing better guidelines for trading animals that could transmit further infections and epidemics in disease free nations. PMID:27227480
-
Subramanian, Gayatri; Kuzmanovic, Teodora; Zhang, Ying; Peter, Cara Beate; Veleeparambil, Manoj; Chakravarti, Ritu; Sen, Ganes C; Chattopadhyay, Saurabh
2018-01-01
The interferon (IFN) system represents the first line of defense against a wide range of viruses. Virus infection rapidly triggers the transcriptional induction of IFN-β and IFN Stimulated Genes (ISGs), whose protein products act as viral restriction factors by interfering with specific stages of virus life cycle, such as entry, transcription, translation, genome replication, assembly and egress. Here, we report a new mode of action of an ISG, IFN-induced TDRD7 (tudor domain containing 7) inhibited paramyxovirus replication by inhibiting autophagy. TDRD7 was identified as an antiviral gene by a high throughput screen of an ISG shRNA library for blocking IFN's protective effect against Sendai virus (SeV) replication. The antiviral activity of TDRD7 against SeV, human parainfluenza virus 3 and respiratory syncytial virus was confirmed by its genetic ablation or ectopic expression in several types of mouse and human cells. TDRD7's antiviral action was mediated by its ability to inhibit autophagy, a cellular catabolic process which was robustly induced by SeV infection and required for its replication. Mechanistic investigation revealed that TDRD7 interfered with the activation of AMP-dependent kinase (AMPK), an enzyme required for initiating autophagy. AMPK activity was required for efficient replication of several paramyxoviruses, as demonstrated by its genetic ablation or inhibition of its activity by TDRD7 or chemical inhibitors. Therefore, our study has identified a new antiviral ISG with a new mode of action.
-
Sánchez-Sampedro, L; Mejías-Pérez, E; S Sorzano, Carlos Óscar; Nájera, J L; Esteban, M
2016-07-15
The NYVAC poxvirus vector is used as vaccine candidate for HIV and other diseases, although there is only limited experimental information on its immunogenicity and effectiveness for use against human pathogens. Here we defined the selective advantage of NYVAC vectors in a mouse model by comparing the immune responses and protection induced by vectors that express the LACK (Leishmania-activated C-kinase antigen), alone or with insertion of the viral host range gene C7L that allows the virus to replicate in human cells. Using DNA prime/virus boost protocols, we show that replication-competent NYVAC-LACK that expresses C7L (NYVAC-LACK-C7L) induced higher-magnitude polyfunctional CD8(+) and CD4(+) primary adaptive and effector memory T cell responses (IFNγ, TNFα, IL-2, CD107a) to LACK antigen than non-replicating NYVAC-LACK. Compared to NYVAC-LACK, the NYVAC-LACK-C7L-induced CD8(+) T cell population also showed higher proliferation when stimulated with LACK antigen. After a challenge by subcutaneous Leishmania major metacyclic promastigotes, NYVAC-LACK-C7L-vaccinated mouse groups showed greater protection than the NYVAC-LACK-vaccinated group. Our results indicate that the type and potency of immune responses induced by LACK-expressing NYVAC vectors is improved by insertion of the C7L gene, and that a replication-competent vector as a vaccine renders greater protection against a human pathogen than a non-replicating vector. Copyright © 2016 Elsevier B.V. All rights reserved.
-
Swenson, Dana L; Warfield, Kelly L; Larsen, Tom; Alves, D Anthony; Coberley, Sadie S; Bavari, Sina
2008-05-01
Virus-like particle (VLP)-based vaccines have the advantage of being morphologically and antigenically similar to the live virus from which they are derived. Expression of the glycoprotein and VP40 matrix protein from Lake Victoria marburgvirus (MARV) results in spontaneous production of VLPs in mammalian cells. Guinea pigs vaccinated with Marburg virus VLPs (mVLPs) or inactivated MARV (iMARV) develop homologous humoral and T-cell responses and are completely protected from a lethal homologous MARV challenge. To determine whether mVLPs based on the Musoke (aka Lake Victoria) isolate of MARV could broadly protect against diverse isolates of MARV, guinea pigs were vaccinated with mVLPs or iMARV-Musoke and challenged with MARV-Musoke, -Ravn or -Ci67. Prior to challenge, the mVLP- and iMARV-vaccinated guinea pigs had high levels of homologous MARV-Musoke and heterologous MARV-Ravn and -Ci67 antibodies. The Musoke-based mVLPs and iMARV vaccines provided complete protection in guinea pigs against viremia, viral replication and pathological changes in tissues, and lethal disease following challenge with MARV-Musoke, -Ravn or -Ci67. Guinea pigs vaccinated with RIBI adjuvant alone and infected with guinea pig-adapted MARV-Musoke, -Ravn or -Ci67 had histopathologic findings similar to those seen in the nonhuman primate model for MARV infection. Based on the strong protection observed in guinea pigs, we next vaccinated cynomolgus macaques with Musoke-based mVLPs and showed the VLP-vaccinated monkeys were broadly protected against three isolates of MARV (Musoke, Ravn and Ci67). Musoke mVLPs are effective at inducing broad heterologous immunity and protection against multiple MARV isolates.
-
Carrascosa, Angel L; Bustos, María J; Nogal, María L; González de Buitrago, Gonzalo; Revilla, Yolanda
2002-03-15
Permissive Vero cells develop apoptosis, as characterized by DNA fragmentation, caspases activation, cytosolic release of mitochondrial cytochrome c, and flow cytometric analysis of DNA content, upon infection with African swine fever virus (ASFV). To determine the step in virus replication that triggers apoptosis, we used UV-inactivated virus, inhibitors of protein and nucleic acid synthesis, and lysosomotropic drugs that block virus uncoating. ASFV-induced apoptosis was accompanied by caspase-3 activation, which was detected even in the presence of either cytosine arabinoside or cycloheximide, indicating that viral DNA replication and protein synthesis were not required to activate the apoptotic process. The activation of caspase-3 was released from chloroquine inhibition 2 h after virus absorption, while the infection with UV-inactivated ASFV did not induce the activation of the caspase cascade. We conclude that ASFV induces apoptosis in the infected cell by an intracellular pathway probably triggered during the process of virus uncoating.
-
Influenza A viruses of avian origin circulating in pigs and other mammals.
Urbaniak, Kinga; Kowalczyk, Andrzej; Markowska-Daniel, Iwona
2014-01-01
Influenza A viruses (IAVs) are zoonotic agents, capable of crossing the species barriers. Nowadays, they still constitute a great challenge worldwide. The natural reservoir of all influenza A viruses are wild aquatic birds, despite the fact they have been isolated from a number of avian and mammalian species, including humans. Even when influenza A viruses are able to get into another than waterfowl population, they are often unable to efficiently adapt and transmit between individuals. Only in rare cases, these viruses are capable of establishing a new lineage. To succeed a complete adaptation and further transmission between species, influenza A virus must overcome a species barrier, including adaptation to the receptors of a new host, which would allow the virus-cell binding, virus replication and, then, animal-to-animal transmission. For many years, pigs were thought to be intermediate host for adaptation of avian influenza viruses to humans, because of their susceptibility to infection with both, avian and human influenza viruses, which supported hypothesis of pigs as a 'mixing vessel'. In this review, the molecular factors necessary for interspecies transmission are described, with special emphasis on adaptation of avian influenza viruses to the pig population. In addition, this review gives the information about swine influenza viruses circulating around the world with special emphasis on Polish strains.
-
Are Ducks Contributing to the Endemicity of Highly Pathogenic H5N1 Influenza Virus in Asia?†
Sturm-Ramirez, K. M.; Hulse-Post, D. J.; Govorkova, E. A.; Humberd, J.; Seiler, P.; Puthavathana, P.; Buranathai, C.; Nguyen, T. D.; Chaisingh, A.; Long, H. T.; Naipospos, T. S. P.; Chen, H.; Ellis, T. M.; Guan, Y.; Peiris, J. S. M.; Webster, R. G.
2005-01-01
Wild waterfowl are the natural reservoir of all influenza A viruses, and these viruses are usually nonpathogenic in these birds. However, since late 2002, H5N1 outbreaks in Asia have resulted in mortality among waterfowl in recreational parks, domestic flocks, and wild migratory birds. The evolutionary stasis between influenza virus and its natural host may have been disrupted, prompting us to ask whether waterfowl are resistant to H5N1 influenza virus disease and whether they can still act as a reservoir for these viruses. To better understand the biology of H5N1 viruses in ducks and attempt to answer this question, we inoculated juvenile mallards with 23 different H5N1 influenza viruses isolated in Asia between 2003 and 2004. All virus isolates replicated efficiently in inoculated ducks, and 22 were transmitted to susceptible contacts. Viruses replicated to higher levels in the trachea than in the cloaca of both inoculated and contact birds, suggesting that the digestive tract is not the main site of H5N1 influenza virus replication in ducks and that the fecal-oral route may no longer be the main transmission path. The virus isolates' pathogenicities varied from completely nonpathogenic to highly lethal and were positively correlated with tracheal virus titers. Nevertheless, the eight virus isolates that were nonpathogenic in ducks replicated and transmitted efficiently to naïve contacts, suggesting that highly pathogenic H5N1 viruses causing minimal signs of disease in ducks can propagate silently and efficiently among domestic and wild ducks in Asia and that they represent a serious threat to human and veterinary public health. PMID:16103179
-
1990-06-30
lentiviral systems including equine infectious anemia virus (EIAV), visna virus, and simian immunodeficiency virus (SIV) (119,120,154). For EIAV, it is clear...a pig-tailed macaque that possesses altered biologic and antigenic properties leading to a broader host-range and a rapid, fatal immunodeficiency ...envelope/LTR region of a replication-defective variant of feline leukemia virus (FeLV), when introduced into a replication competent construct of FeLV, was
-
McLinden, James H.; Stapleton, Jack T.; Klinzman, Donna; Murthy, Krishna K.; Chang, Qing; Kaufman, Thomas M.; Bhattarai, Nirjal
2013-01-01
GB virus type C (GBV-C) is a lymphotropic virus that can cause persistent infection in humans. GBV-C is not associated with any disease, but is associated with reduced mortality in human immunodeficiency virus type 1 (HIV-1)-infected individuals. Related viruses have been isolated from chimpanzees (GBV-Ccpz) and from New World primates (GB virus type A, GBV-A). These viruses are also capable of establishing persistent infection. We determined the nucleotide sequence encoding the envelope glycoprotein (E2) of two GBV-Ccpz isolates obtained from the sera of captive chimpanzees. The deduced GBV-Ccpz E2 protein differed from human GBV-C by 31 % at the amino acid level. Similar to human GBV-C E2, expression of GBV-Ccpz E2 in a tet-off human CD4+ Jurkat T-cell line significantly inhibited the replication of diverse HIV-1 isolates. This anti-HIV-replication effect of GBV-Ccpz E2 protein was reversed by maintaining cells in doxycycline to reduce E2 expression. Previously, we found a 17 aa region within human GBV-C E2 that was sufficient to inhibit HIV-1. Although GBV-Ccpz E2 differed by 3 aa differences in this region, the chimpanzee GBV-C 17mer E2 peptide inhibited HIV-1 replication. Similarly, the GBV-A peptide that aligns with this GBV-C E2 region inhibited HIV-1 replication despite sharing only 5 aa with the human GBV-C E2 sequence. Thus, despite amino acid differences, the peptide region on both the GBV-Ccpz and the GBV-A E2 protein inhibit HIV-1 replication similar to human GBV-C. Consequently, GBV-Ccpz or GBV-A infection of non-human primates may provide an animal model to study GB virus–HIV interactions. PMID:23288422
-
Taguwa, Shuhei; Maringer, Kevin; Li, Xiaokai; Bernal-Rubio, Dabeiba; Rauch, Jennifer N.; Gestwicki, Jason E.; Andino, Raul; Fernandez-Sesma, Ana; Frydman, Judith
2015-01-01
Summary Viral protein homeostasis depends entirely on the machinery of the infected cell. Accordingly, viruses can illuminate the interplay between cellular proteostasis components and their distinct substrates. Here we define how the Hsp70 chaperone network mediates the dengue virus life cycle. Cytosolic Hsp70 isoforms are required at distinct steps of the viral cycle, including entry, RNA replication and virion biogenesis. Hsp70 function at each step is specified by nine distinct DNAJ cofactors. Of these, DnaJB11 relocalizes to virus-induced replication complexes to promote RNA synthesis, while DnaJB6 associates with capsid protein and facilitates virion biogenesis. Importantly, an allosteric Hsp70 inhibitor, JG40, potently blocks infection of different dengue serotypes in human primary blood cells without eliciting viral resistance or exerting toxicity to the host cells. JG40 also blocks replication of other medically-important flaviviruses including yellow fever, West Nile and Japanese encephalitis viruses. Thus, targeting host Hsp70 subnetworks provides a path for broad-spectrum antivirals. PMID:26582131
-
Li, Lili; Zhao, Hui; Liu, Ping; Li, Chunfeng; Quanquin, Natalie; Ji, Xue; Sun, Nina; Du, Peishuang; Qin, Cheng-Feng; Lu, Ning; Cheng, Genhong
2018-06-19
Zika virus infection stimulates a type I interferon (IFN) response in host cells, which suppresses viral replication. Type I IFNs exert antiviral effects by inducing the expression of hundreds of IFN-stimulated genes (ISGs). To screen for antiviral ISGs that restricted Zika virus replication, we individually knocked out 21 ISGs in A549 lung cancer cells and identified PARP12 as a strong inhibitor of Zika virus replication. Our findings suggest that PARP12 mediated the ADP-ribosylation of NS1 and NS3, nonstructural viral proteins that are involved in viral replication and modulating host defense responses. This modification of NS1 and NS3 triggered their proteasome-mediated degradation. These data increase our understanding of the antiviral activity of PARP12 and suggest a molecular basis for the potential development of therapeutics against Zika virus. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.
-
MYC-induced reprogramming of glutamine catabolism supports optimal virus replication
Thai, Minh; Thaker, Shivani K.; Feng, Jun; Du, Yushen; Hu, Hailiang; Ting Wu, Ting; Graeber, Thomas G.; Braas, Daniel; Christofk, Heather R.
2015-01-01
Viruses rewire host cell glucose and glutamine metabolism to meet the bioenergetic and biosynthetic demands of viral propagation. However, the mechanism by which viruses reprogram glutamine metabolism and the metabolic fate of glutamine during adenovirus infection have remained elusive. Here, we show MYC activation is necessary for adenovirus-induced upregulation of host cell glutamine utilization and increased expression of glutamine transporters and glutamine catabolism enzymes. Adenovirus-induced MYC activation promotes increased glutamine uptake, increased use of glutamine in reductive carboxylation and increased use of glutamine in generating hexosamine pathway intermediates and specific amino acids. We identify glutaminase (GLS) as a critical enzyme for optimal adenovirus replication and demonstrate that GLS inhibition decreases replication of adenovirus, herpes simplex virus 1 and influenza A in cultured primary cells. Our findings show that adenovirus-induced reprogramming of glutamine metabolism through MYC activation promotes optimal progeny virion generation, and suggest that GLS inhibitors may be useful therapeutically to reduce replication of diverse viruses. PMID:26561297
-
A novel sheet-like virus particle array is a hallmark of Zika virus infection.
Liu, Jun; Kline, Brandon A; Kenny, Tara A; Smith, Darci R; Soloveva, Veronica; Beitzel, Brett; Pang, Song; Lockett, Stephen; Hess, Harald F; Palacios, Gustavo; Kuhn, Jens H; Sun, Mei G; Zeng, Xiankun
2018-04-25
Zika virus (ZIKV) is an emerging flavivirus that caused thousands of human infections in recent years. Compared to other human flaviviruses, ZIKV replication is not well understood. Using fluorescent, transmission electron, and focused ion beam-scanning electron microscopy, we examined ZIKV replication dynamics in Vero 76 cells and in the brains of infected laboratory mice. We observed the progressive development of a perinuclear flaviviral replication factory both in vitro and in vivo. In vitro, we illustrated the ZIKV lifecycle from particle cell entry to egress. ZIKV particles assembled and aggregated in an induced convoluted membrane structure and ZIKV strain-specific membranous vesicles. While most mature virus particles egressed via membrane budding, some particles also likely trafficked through late endosomes and egressed through membrane abscission. Interestingly, we consistently observed a novel sheet-like virus particle array consisting of a single layer of ZIKV particles. Our study further defines ZIKV replication and identifies a novel hallmark of ZIKV infection.
-
Pathogens and parasites: strategies and challenges
2000-01-01
The threat of emerging infections grows with the swelling tide of the human population and the continued disregard for the health of the environment. One of our most urgent challenges in public health is to understand the evolution and natural history of pathogens and parasites and how a sudden shift in virulence or in targeted host population may occur without warning. Viruses call for especially close watching. They are mostly genes and have mastered the art of manipulating other genes. Some are planktonic in the world's oceans, numbering 10 billion per liter of seawater; some are planktonic in our blood; some lie low inside cells; some take over a cell's replication machinery and explode the cell with new copies of themselves; and some splice their genes seamlessly into our chromosomes. The twin themes of genetic diversity and natural selection are explored in this review, with their relevance to viruses, the vertebrate immune system, virulence, and communicable disease epidemiology. PMID:16389321
-
Effect of serial pig passages on the adaptation of an avian H9N2 influenza virus to swine.
Mancera Gracia, Jose Carlos; Van den Hoecke, Silvie; Saelens, Xavier; Van Reeth, Kristien
2017-01-01
H9N2 avian influenza viruses are endemic in poultry in Asia and the Middle East. These viruses sporadically cause dead-end infections in pigs and humans raising concerns about their potential to adapt to mammals or reassort with human or swine influenza viruses. We performed ten serial passages with an avian H9N2 virus (A/quail/Hong Kong/G1/1997) in influenza naïve pigs to assess the potential of this virus to adapt to swine. Virus replication in the entire respiratory tract and nasal virus excretion were examined after each passage and we deep sequenced viral genomic RNA of the parental and passage four H9N2 virus isolated from the nasal mucosa and lung. The parental H9N2 virus caused a productive infection in pigs with a predominant tropism for the nasal mucosa, whereas only 50% lung samples were virus-positive. In contrast, inoculation of pigs with passage four virus resulted in viral replication in the entire respiratory tract. Subsequent passages were associated with reduced virus replication in the lungs and infectious virus was no longer detectable in the upper and lower respiratory tract of inoculated pigs at passage ten. The broader tissue tropism after four passages was associated with an amino acid residue substitution at position 225, within the receptor-binding site of the hemagglutinin. We also compared the parental H9N2, passage four H9N2 and the 2009 pandemic H1N1 (pH1N1) virus in a direct contact transmission experiment. Whereas only one out of six contact pigs showed nasal virus excretion of the wild-type H9N2 for more than four days, all six contact animals shed the passage four H9N2 virus. Nevertheless, the amount of excreted virus was significantly lower when compared to that of the pH1N1, which readily transmitted and replicated in all six contact animals. Our data demonstrate that serial passaging of H9N2 virus in pigs enhances its replication and transmissibility. However, full adaptation of an avian H9N2 virus to pigs likely requires an extensive set of mutations.
-
Effect of serial pig passages on the adaptation of an avian H9N2 influenza virus to swine
Van den Hoecke, Silvie; Saelens, Xavier; Van Reeth, Kristien
2017-01-01
H9N2 avian influenza viruses are endemic in poultry in Asia and the Middle East. These viruses sporadically cause dead-end infections in pigs and humans raising concerns about their potential to adapt to mammals or reassort with human or swine influenza viruses. We performed ten serial passages with an avian H9N2 virus (A/quail/Hong Kong/G1/1997) in influenza naïve pigs to assess the potential of this virus to adapt to swine. Virus replication in the entire respiratory tract and nasal virus excretion were examined after each passage and we deep sequenced viral genomic RNA of the parental and passage four H9N2 virus isolated from the nasal mucosa and lung. The parental H9N2 virus caused a productive infection in pigs with a predominant tropism for the nasal mucosa, whereas only 50% lung samples were virus-positive. In contrast, inoculation of pigs with passage four virus resulted in viral replication in the entire respiratory tract. Subsequent passages were associated with reduced virus replication in the lungs and infectious virus was no longer detectable in the upper and lower respiratory tract of inoculated pigs at passage ten. The broader tissue tropism after four passages was associated with an amino acid residue substitution at position 225, within the receptor-binding site of the hemagglutinin. We also compared the parental H9N2, passage four H9N2 and the 2009 pandemic H1N1 (pH1N1) virus in a direct contact transmission experiment. Whereas only one out of six contact pigs showed nasal virus excretion of the wild-type H9N2 for more than four days, all six contact animals shed the passage four H9N2 virus. Nevertheless, the amount of excreted virus was significantly lower when compared to that of the pH1N1, which readily transmitted and replicated in all six contact animals. Our data demonstrate that serial passaging of H9N2 virus in pigs enhances its replication and transmissibility. However, full adaptation of an avian H9N2 virus to pigs likely requires an extensive set of mutations. PMID:28384328
-
Crescenzo-Chaigne, Bernadette; Barbezange, Cyril; van der Werf, Sylvie
2008-01-01
Background The transcription/replication of the influenza viruses implicate the terminal nucleotide sequences of viral RNA, which comprise sequences at the extremities conserved among the genomic segments as well as variable 3' and 5' non-coding (NC) regions. The plasmid-based system for the in vivo reconstitution of functional ribonucleoproteins, upon expression of viral-like RNAs together with the nucleoprotein and polymerase proteins has been widely used to analyze transcription/replication of influenza viruses. It was thus shown that the type A polymerase could transcribe and replicate type A, B, or C vRNA templates whereas neither type B nor type C polymerases were able to transcribe and replicate type A templates efficiently. Here we studied the importance of the NC regions from the seven segments of type C influenza virus for efficient transcription/replication by the type A and C polymerases. Results The NC sequences of the seven genomic segments of the type C influenza virus C/Johannesburg/1/66 strain were found to be more variable in length than those of the type A and B viruses. The levels of transcription/replication of viral-like vRNAs harboring the NC sequences of the respective type C virus segments flanking the CAT reporter gene were comparable in the presence of either type C or type A polymerase complexes except for the NS and PB2-like vRNAs. For the NS-like vRNA, the transcription/replication level was higher after introduction of a U residue at position 6 in the 5' NC region as for all other segments. For the PB2-like vRNA the CAT expression level was particularly reduced with the type C polymerase. Analysis of mutants of the 5' NC sequence in the PB2-like vRNA, the shortest 5' NC sequence among the seven segments, showed that additional sequences within the PB2 ORF were essential for the efficiency of transcription but not replication by the type C polymerase complex. Conclusion In the context of a PB2-like reporter vRNA template, the sequence upstream the polyU stretch plays a role in the transcription/replication process by the type C polymerase complex. PMID:18973655
-
The Mechanism of Viral Replication. Structure of Replication Complexes of Encephalomyocarditis Virus
Thach, Sigrid S.; Dobbertin, Darrell; Lawrence, Charles; Golini, Fred; Thach, Robert E.
1974-01-01
The structure of the purified replicative intermediate of encephalomyocarditis virus was determined by electron microscopy. Approximately 80% of the replicative intermediate complexes were characterized by a filament of double-stranded RNA of widely variable length, which had a “bush” of single-stranded RNA at one end. In many examples one or more additional single-stranded bushes were appended internally to the double-stranded RNA filament. These results support the view that before deproteinization, replicative intermediate contains little if any double-stranded RNA. Images PMID:4366773
-
Le Coupanec, Alain; Tchankouo-Nguetcheu, Stéphane; Roux, Pascal; Khun, Huot; Huerre, Michel; Morales-Vargas, Ronald; Enguehard, Margot; Lavillette, Dimitri; Missé, Dorothée
2017-01-01
Arthropod-borne virus (arbovirus) infections cause several emerging and resurgent infectious diseases in humans and animals. Chikungunya-affected areas often overlap with dengue-endemic areas. Concurrent dengue virus (DENV) and chikungunya virus (CHIKV) infections have been detected in travelers returning from regions of endemicity. CHIKV and DENV co-infected Aedes albopictus have also been collected in the vicinity of co-infected human cases, emphasizing the need to study co-infections in mosquitoes. We thus aimed to study the pathogen-pathogen interaction involved in these co-infections in DENV/CHIKV co-infected Aedes aegypti mosquitoes. In mono-infections, we detected CHIKV antigens as early as 4 days post-virus exposure in both the midgut (MG) and salivary gland (SG), whereas we detected DENV serotype 2 (DENV-2) antigens from day 5 post-virus exposure in MG and day 10 post-virus exposure in SG. Identical infection rates were observed for singly and co-infected mosquitoes, and facilitation of the replication of both viruses at various times post-viral exposure. We observed a higher replication for DENV-2 in SG of co-infected mosquitoes. We showed that mixed CHIKV and DENV infection facilitated viral replication in Ae. aegypti. The outcome of these mixed infections must be further studied to increase our understanding of pathogen-pathogen interactions in host cells. PMID:28777313
-
Le Coupanec, Alain; Tchankouo-Nguetcheu, Stéphane; Roux, Pascal; Khun, Huot; Huerre, Michel; Morales-Vargas, Ronald; Enguehard, Margot; Lavillette, Dimitri; Missé, Dorothée; Choumet, Valérie
2017-08-04
Arthropod-borne virus (arbovirus) infections cause several emerging and resurgent infectious diseases in humans and animals. Chikungunya-affected areas often overlap with dengue-endemic areas. Concurrent dengue virus (DENV) and chikungunya virus (CHIKV) infections have been detected in travelers returning from regions of endemicity. CHIKV and DENV co-infected Aedes albopictus have also been collected in the vicinity of co-infected human cases, emphasizing the need to study co-infections in mosquitoes. We thus aimed to study the pathogen-pathogen interaction involved in these co-infections in DENV/CHIKV co-infected Aedes aegypti mosquitoes. In mono-infections, we detected CHIKV antigens as early as 4 days post-virus exposure in both the midgut (MG) and salivary gland (SG), whereas we detected DENV serotype 2 (DENV-2) antigens from day 5 post-virus exposure in MG and day 10 post-virus exposure in SG. Identical infection rates were observed for singly and co-infected mosquitoes, and facilitation of the replication of both viruses at various times post-viral exposure. We observed a higher replication for DENV-2 in SG of co-infected mosquitoes. We showed that mixed CHIKV and DENV infection facilitated viral replication in Ae. aegypti . The outcome of these mixed infections must be further studied to increase our understanding of pathogen-pathogen interactions in host cells.
-
Yamamoto, T.; Batts, W.N.; Winton, J.R.
1992-01-01
The ability of two rhabdoviruses, infectious hematopoietic necrosis virus (IHNV) and viral hemorrhagic septicemia virus (VHSV), to infect fish skin was investigated by in vitro infection of excised tissues. Virus replication was determined by plaque assay of homogenized tissue extracts, and the virus antigen was detected by immunohistology of tissue sections. Gill, fin, and ventral abdominal skin tissues of rainbow trout Oncorhynchus mykiss that had been infected in vitro with a virulent strain of IHNV (193–110) produced substantial increases in virus titer within 24 h. Titers continued to increase up until day 3 of incubation; by this time, virus had increased 1,000-fold or more. This increase in IHNV titer occurred in epidermal tissues of fingerlings and of older fish. In another experiment, IHNV replicated in excised rainbow trout tissues whether the fish had been subject to prior infection with a virulent strain of IHNV (Western Regional Aquaculture Consortium isolate) or whether the fish had been infected previously with an attenuated strain of the virus (Nan Scott Lake, with 100 passes in culture). A virulent strain of VHSV (23/75) replicated effectively in excised gill tissues and epidermal tissues of rainbow trout and chinook salmon O. tshawytscha; however, the avirulent North American strain of VHSV (Makah) replicated poorly or not at all.
-
The molecular biology of Bluetongue virus replication.
Patel, Avnish; Roy, Polly
2014-03-01
The members of Orbivirus genus within the Reoviridae family are arthropod-borne viruses which are responsible for high morbidity and mortality in ruminants. Bluetongue virus (BTV) which causes disease in livestock (sheep, goat, cattle) has been in the forefront of molecular studies for the last three decades and now represents the best understood orbivirus at a molecular and structural level. The complex nature of the virion structure has been well characterised at high resolution along with the definition of the virus encoded enzymes required for RNA replication; the ordered assembly of the capsid shell as well as the protein and genome sequestration required for it; and the role of host proteins in virus entry and virus release. More recent developments of Reverse Genetics and Cell-Free Assembly systems have allowed integration of the accumulated structural and molecular knowledge to be tested at meticulous level, yielding higher insight into basic molecular virology, from which the rational design of safe efficacious vaccines has been possible. This article is centred on the molecular dissection of BTV with a view to understanding the role of each protein in the virus replication cycle. These areas are important in themselves for BTV replication but they also indicate the pathways that related viruses, which includes viruses that are pathogenic to man and animals, might also use providing an informed starting point for intervention or prevention. Copyright © 2014 Elsevier B.V. All rights reserved.
-
Schuchman, Ryan; Kilianski, Andy; Piper, Amanda; Vancini, Ricardo; Ribeiro, José M C; Sprague, Thomas R; Nasar, Farooq; Boyd, Gabrielle; Hernandez, Raquel; Glaros, Trevor
2018-05-09
Recent advances in mass spectrometry methods and instrumentation now allow for more accurate identification of proteins in low abundance. This technology was applied to Sindbis virus, the prototypical alphavirus to investigate the viral proteome. To determine if host proteins are specifically packaged into alphavirus virions, Sindbis virus (SINV) was grown in multiple host cells representing vertebrate and mosquito hosts and total protein content of purified virions was determined. This analysis identified host factors not previously associated with alphavirus entry, replication, or egress. One host protein, sorting nexin 5 (SNX5), was shown to be critical for the replication of three different alphaviruses, Sindbis, Mayaro and Chikungunya virus. The most significant finding was that in addition to the host proteins, SINV non-structural protein 2 (nsP2) was detected within virions grown in all host cells examined. The protein and RNA-interacting capabilities of nsP2 coupled with its presence in the virion support a role for nsP2 during packaging and/or entry of progeny virus. This function has not been identified for this protein. Taken together, this strategy identified at least one host factor integrally involved in alphavirus replication. Identification of other host proteins provides insight into alphavirus-host interactions during viral replication in both vertebrate and invertebrate hosts. This method of virus proteome analysis may also be useful for the identification of protein candidates for host-based therapeutics. IMPORTANCE Pathogenic Alphaviruses, such as Chikungunya and Mayaro virus, continue to plague public health in developing and developed countries alike. Alphaviruses belong to a group of viruses vectored in nature by hematophagous (blood-feeding) insects and are termed Arboviruses (arthropod-borne viruses). This group of viruses contains many human pathogens such as dengue fever, West Nile and Yellow fever viruses. With few exceptions there are no vaccines or prophylactics for these agents leaving one third of the world population at risk of infection. Identifying effective antivirals has been a long term goal for combating these diseases not only because of the lack of vaccines but also because they are effective during an ongoing epidemic. Mass spectrometry-based analysis of the Sindbis virus proteome can be effective in identifying host genes involved in virus replication and novel functions for virus proteins. Identification of these factors is invaluable for the prophylaxis of this group of viruses. Copyright © 2018 Schuchman et al.
-
Critical Role of HAX-1 in Promoting Avian Influenza Virus Replication in Lung Epithelial Cells
He, Ganlin; Cardona, Carol J.
2018-01-01
The PB1-F2 protein of influenza A virus has been considered a virulence factor, but its function in inducing apoptosis may be of disadvantage to viral replication. Host mechanisms to regulate PB1-F2-induced apoptosis remain unknown. We generated a PB1-F2-deficient avian influenza virus (AIV) H9N2 and found that the mutant virus replicated less efficiently in human lung epithelial cells. The PB1-F2-deficient virus produced less apoptotic cells, indicating that PB1-F2 of the H9N2 virus promotes apoptosis, occurring at the early stage of infection, in the lung epithelial cells. To understand how host cells regulate PB1-F2-induced apoptosis, we explored to identify cellular proteins interacting with PB1-F2 and found that HCLS1-associated protein X-1 (HAX-1), located mainly in the mitochondria as an apoptotic inhibitor, interacted with PB1-F2. Increased procaspase-9 activations, induced by PB1-F2, could be suppressed by HAX-1. In HAX-1 knockdown A549 cells, the replication of AIV H9N2 was suppressed in parallel to the activation of caspase-3 activation, which increased at the early stage of infection. We hypothesize that HAX-1 promotes AIV replication by interacting with PB1-F2, resulting in the suppression of apoptosis, prolonged cell survival, and enhancement of viral replication. Our data suggest that HAX-1 may be a promoting factor for AIV H9N2 replication through desensitizing PB1-F2 from its apoptotic induction in human lung epithelial cells. PMID:29576744
-
de Vries, Rory D.; Ludlow, Martin; Verburgh, R. Joyce; van Amerongen, Geert; Yüksel, Selma; Nguyen, D. Tien; McQuaid, Stephen; Osterhaus, Albert D. M. E.; Duprex, W. Paul
2014-01-01
ABSTRACT Measles virus (MV) is being considered for global eradication, which would likely reduce compliance with MV vaccination. As a result, children will grow up without MV-specific immunity, creating a potential niche for closely related animal morbilliviruses such as canine distemper virus (CDV). Natural CDV infection causing clinical signs has never been reported in humans, but recent outbreaks in captive macaques have shown that CDV can cause disease in primates. We studied the virulence and tropism of recombinant CDV expressing enhanced green fluorescent protein in naive and measles-vaccinated cynomolgus macaques. In naive animals CDV caused viremia and fever and predominantly infected CD150+ lymphocytes and dendritic cells. Virus was reisolated from the upper and lower respiratory tracts, but infection of epithelial or neuronal cells was not detectable at the time points examined, and the infections were self-limiting. This demonstrates that CDV readily infects nonhuman primates but suggests that additional mutations are necessary to achieve full virulence in nonnatural hosts. Partial protection against CDV was observed in measles-vaccinated macaques, as demonstrated by accelerated control of virus replication and limited shedding from the upper respiratory tract. While neither CDV infection nor MV vaccination induced detectable cross-reactive neutralizing antibodies, MV-specific neutralizing antibody levels of MV-vaccinated macaques were boosted by CDV challenge infection, suggesting that cross-reactive VN epitopes exist. Rapid increases in white blood cell counts in MV-vaccinated macaques following CDV challenge suggested that cross-reactive cellular immune responses were also present. This study demonstrates that zoonotic morbillivirus infections can be controlled by measles vaccination. IMPORTANCE Throughout history viral zoonoses have had a substantial impact on human health. Given the drive toward global eradication of measles, it is essential to understand the zoonotic potential of animal morbilliviruses. Morbilliviruses are thought to have evolved from a common ancestral virus that jumped species and adapted to new hosts. Recently, canine distemper virus (CDV), a morbillivirus normally restricted to carnivores, caused disease outbreaks in nonhuman primates. Here, we report that experimental CDV infection of monkeys resulted in fever and leukopenia. The virus replicated to high levels in lymphocytes but did not spread to epithelial cells or the central nervous system. Importantly, like measles virus in macaques, the infections were self-limiting. In measles-vaccinated macaques CDV was cleared more rapidly, resulting in limited virus shedding from the upper respiratory tract. These studies demonstrate that although CDV can readily infect primates, measles immunity is protective, and CDV infection is self-limiting. PMID:24501402
-
de Vries, Rory D; Ludlow, Martin; Verburgh, R Joyce; van Amerongen, Geert; Yüksel, Selma; Nguyen, D Tien; McQuaid, Stephen; Osterhaus, Albert D M E; Duprex, W Paul; de Swart, Rik L
2014-04-01
Measles virus (MV) is being considered for global eradication, which would likely reduce compliance with MV vaccination. As a result, children will grow up without MV-specific immunity, creating a potential niche for closely related animal morbilliviruses such as canine distemper virus (CDV). Natural CDV infection causing clinical signs has never been reported in humans, but recent outbreaks in captive macaques have shown that CDV can cause disease in primates. We studied the virulence and tropism of recombinant CDV expressing enhanced green fluorescent protein in naive and measles-vaccinated cynomolgus macaques. In naive animals CDV caused viremia and fever and predominantly infected CD150(+) lymphocytes and dendritic cells. Virus was reisolated from the upper and lower respiratory tracts, but infection of epithelial or neuronal cells was not detectable at the time points examined, and the infections were self-limiting. This demonstrates that CDV readily infects nonhuman primates but suggests that additional mutations are necessary to achieve full virulence in nonnatural hosts. Partial protection against CDV was observed in measles-vaccinated macaques, as demonstrated by accelerated control of virus replication and limited shedding from the upper respiratory tract. While neither CDV infection nor MV vaccination induced detectable cross-reactive neutralizing antibodies, MV-specific neutralizing antibody levels of MV-vaccinated macaques were boosted by CDV challenge infection, suggesting that cross-reactive VN epitopes exist. Rapid increases in white blood cell counts in MV-vaccinated macaques following CDV challenge suggested that cross-reactive cellular immune responses were also present. This study demonstrates that zoonotic morbillivirus infections can be controlled by measles vaccination. Throughout history viral zoonoses have had a substantial impact on human health. Given the drive toward global eradication of measles, it is essential to understand the zoonotic potential of animal morbilliviruses. Morbilliviruses are thought to have evolved from a common ancestral virus that jumped species and adapted to new hosts. Recently, canine distemper virus (CDV), a morbillivirus normally restricted to carnivores, caused disease outbreaks in nonhuman primates. Here, we report that experimental CDV infection of monkeys resulted in fever and leukopenia. The virus replicated to high levels in lymphocytes but did not spread to epithelial cells or the central nervous system. Importantly, like measles virus in macaques, the infections were self-limiting. In measles-vaccinated macaques CDV was cleared more rapidly, resulting in limited virus shedding from the upper respiratory tract. These studies demonstrate that although CDV can readily infect primates, measles immunity is protective, and CDV infection is self-limiting.
-
Kandeil, Ahmed; Moatasim, Yassmin; Gomaa, Mokhtar R; Shehata, Mahmoud M; El-Shesheny, Rabeh; Barakat, Ahmed; Webby, Richard J; Ali, Mohamed A; Kayali, Ghazi
2016-01-04
Avian influenza H5N1 viruses have been enzootic in Egyptian poultry since 2006. Avian influenza H9N2 viruses which have been circulating in Egyptian poultry since 2011 showed high replication rates in embryonated chicken eggs and mammalian cells. To investigate which gene segment was responsible for increasing replication, we constructed reassortant influenza viruses using the low pathogenic H1N1 PR8 virus as backbone and included individual genes from A/chicken/Egypt/S4456B/2011(H9N2) virus. Then, we invested this finding to improve a PR8-derived H5N1 influenza vaccine strain by incorporation of the NA segment of H9N2 virus instead of the NA of H5N1. The growth properties of this virus and several other forms of reassortant H5 viruses were compared. Finally, we tested the efficacy of this reassortant vaccine strain in chickens. We observed an increase in replication for a reassortant virus expressing the neuraminidase gene (N2) of H9N2 virus relative to that of either parental viruses or reassortant PR8 viruses expressing other genes. Then, we generated an H5N2 vaccine strain based on the H5 from an Egyptian H5N1 virus and the N2 from an Egyptian H9N2 virus on a PR8 backbone. This strain had better replication rates than an H5N2 reassortant strain on an H9N2 backbone and an H5N1 reassortant on a PR8 backbone. This virus was then used to develop a killed, oil-emulsion vaccine and tested for efficacy against H5N1 and H9N2 viruses in chickens. Results showed that this vaccine was immunogenic and reduced mortality and shedding. Our findings suggest that an inactivated PR8-derived H5N2 influenza vaccine is efficacious in poultry against H5N1 and H9N2 viruses and the vaccine seed replicates at a high rate thus improving vaccine production. Copyright © 2015 Elsevier Ltd. All rights reserved.
-
Mänz, Benjamin; de Graaf, Miranda; Mögling, Ramona; Richard, Mathilde; Bestebroer, Theo M; Rimmelzwaan, Guus F; Fouchier, Ron A M
2016-07-01
A strong restriction of the avian influenza A virus polymerase in mammalian cells generally limits viral host-range switching. Although substitutions like E627K in the PB2 polymerase subunit can facilitate polymerase activity to allow replication in mammals, many human H5N1 and H7N9 viruses lack this adaptive substitution. Here, several previously unknown, naturally occurring, adaptive substitutions in PB2 were identified by bioinformatics, and their enhancing activity was verified using in vitro assays. Adaptive substitutions enhanced polymerase activity and virus replication in mammalian cells for avian H5N1 and H7N9 viruses but not for a partially human-adapted H5N1 virus. Adaptive substitutions toward basic amino acids were frequent and were mostly clustered in a putative RNA exit channel in a polymerase crystal structure. Phylogenetic analysis demonstrated divergent dependency of influenza viruses on adaptive substitutions. The novel adaptive substitutions found in this study increase basic understanding of influenza virus host adaptation and will help in surveillance efforts. Influenza viruses from birds jump the species barrier into humans relatively frequently. Such influenza virus zoonoses may pose public health risks if the virus adapts to humans and becomes a pandemic threat. Relatively few amino acid substitutions-most notably in the receptor binding site of hemagglutinin and at positions 591 and 627 in the polymerase protein PB2-have been identified in pandemic influenza virus strains as determinants of host adaptation, to facilitate efficient virus replication and transmission in humans. Here, we show that substantial numbers of amino acid substitutions are functionally compensating for the lack of the above-mentioned mutations in PB2 and could facilitate influenza virus emergence in humans. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
-
Low-Pathogenic Avian Influenza Viruses in Wild House Mice
Shriner, Susan A.; VanDalen, Kaci K.; Mooers, Nicole L.; Ellis, Jeremy W.; Sullivan, Heather J.; Root, J. Jeffrey; Pelzel, Angela M.; Franklin, Alan B.
2012-01-01
Background Avian influenza viruses are known to productively infect a number of mammal species, several of which are commonly found on or near poultry and gamebird farms. While control of rodent species is often used to limit avian influenza virus transmission within and among outbreak sites, few studies have investigated the potential role of these species in outbreak dynamics. Methodology/Principal Findings We trapped and sampled synanthropic mammals on a gamebird farm in Idaho, USA that had recently experienced a low pathogenic avian influenza outbreak. Six of six house mice (Mus musculus) caught on the outbreak farm were presumptively positive for antibodies to type A influenza. Consequently, we experimentally infected groups of naïve wild-caught house mice with five different low pathogenic avian influenza viruses that included three viruses derived from wild birds and two viruses derived from chickens. Virus replication was efficient in house mice inoculated with viruses derived from wild birds and more moderate for chicken-derived viruses. Mean titers (EID50 equivalents/mL) across all lung samples from seven days of sampling (three mice/day) ranged from 103.89 (H3N6) to 105.06 (H4N6) for the wild bird viruses and 102.08 (H6N2) to 102.85 (H4N8) for the chicken-derived viruses. Interestingly, multiple regression models indicated differential replication between sexes, with significantly (p<0.05) higher concentrations of avian influenza RNA found in females compared with males. Conclusions/Significance Avian influenza viruses replicated efficiently in wild-caught house mice without adaptation, indicating mice may be a risk pathway for movement of avian influenza viruses on poultry and gamebird farms. Differential virus replication between males and females warrants further investigation to determine the generality of this result in avian influenza disease dynamics. PMID:22720076
-
Prereplicative events involving simian virus 40 DNA in permissive cells
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rinaldy, A.; Feunteun, J.; Rosenberg, B.H.
1982-01-01
Simian virus 40 DNA molecules were found to be unable to replicate for 9 h after infection, even in cells that were already replicating the DNA of preinfecting simian virus 40; after 9 h, the ability of the DNA to replicate began to rise sharply. The kinetics of activation indicated that each DNA molecule undergoes a series of slow consecutive reactions, not involving T-antigen, before it can replicate. These pre-replicative molecular transformations probably involve configurational changes; their nature and their relation to the initiation of viral DNA synthesis is discussed. Observation of the replicative behavior of one viral DNA inmore » the presence of another was made possible by the use of two different mutants with distinguishable DNAs: a viable deletion mutant containing DNA insensitive to TaqI restriction enzyme was used to provide viral functions required for replication, and is a tsA mutant with TaqI-sensitive DNA was introduced at various times as a probe to determine the ability of the DNA to replicate under different conditions.« less
-
Nagy, Peter D; Pogany, Judit
2010-01-01
The success of RNA viruses as pathogens of plants, animals, and humans depends on their ability to reprogram the host cell metabolism to support the viral infection cycle and to suppress host defense mechanisms. Plus-strand (+)RNA viruses have limited coding potential necessitating that they co-opt an unknown number of host factors to facilitate their replication in host cells. Global genomics and proteomics approaches performed with Tomato bushy stunt virus (TBSV) and yeast (Saccharomyces cerevisiae) as a model host have led to the identification of 250 host factors affecting TBSV RNA replication and recombination or bound to the viral replicase, replication proteins, or the viral RNA. The roles of a dozen host factors involved in various steps of the replication process have been validated in yeast as well as a plant host. Altogether, the large number of host factors identified and the great variety of cellular functions performed by these factors indicate the existence of a truly complex interaction between TBSV and the host cell. This review summarizes the advantages of using a simple plant virus and yeast as a model host to advance our understanding of virus-host interactions at the molecular and cellular levels. The knowledge of host factors gained can potentially be used to inhibit virus replication via gene silencing, expression of dominant negative mutants, or design of specific chemical inhibitors leading to novel specific or broad-range resistance and antiviral tools against (+)RNA plant viruses. Copyright © 2010 Elsevier Inc. All rights reserved.
-
Evidence of Ebola Virus Replication and High Concentration in Semen of a Patient During Recovery.
Barnes, Kayla G; Kindrachuk, Jason; Lin, Aaron E; Wohl, Shirlee; Qu, James; Tostenson, Samantha D; Dorman, William R; Busby, Michele; Siddle, Katherine J; Luo, Cynthia Y; Matranga, Christian B; Davey, Richard T; Sabeti, Pardis C; Chertow, Daniel S
2017-10-15
In one patient over time, we found that concentration of Ebola virus RNA in semen during recovery is remarkably higher than blood at peak illness. Virus in semen is replication-competent with no change in viral genome over time. Presence of sense RNA suggests replication in cells present in semen. Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.
-
Hepatitis B virus molecular biology and pathogenesis.
Lamontagne, R Jason; Bagga, Sumedha; Bouchard, Michael J
2016-01-01
As obligate intracellular parasites, viruses need a host cell to provide a milieu favorable to viral replication. Consequently, viruses often adopt mechanisms to subvert host cellular signaling processes. While beneficial for the viral replication cycle, virus-induced deregulation of host cellular signaling processes can be detrimental to host cell physiology and can lead to virus-associated pathogenesis, including, for oncogenic viruses, cell transformation and cancer progression. Included among these oncogenic viruses is the hepatitis B virus (HBV). Despite the availability of an HBV vaccine, 350-500 million people worldwide are chronically infected with HBV, and a significant number of these chronically infected individuals will develop hepatocellular carcinoma (HCC). Epidemiological studies indicate that chronic infection with HBV is the leading risk factor for the development of HCC. Globally, HCC is the second highest cause of cancer-associated deaths, underscoring the need for understanding mechanisms that regulate HBV replication and the development of HBV-associated HCC. HBV is the prototype member of the Hepadnaviridae family; members of this family of viruses have a narrow host range and predominately infect hepatocytes in their respective hosts. The extremely small and compact hepadnaviral genome, the unique arrangement of open reading frames, and a replication strategy utilizing reverse transcription of an RNA intermediate to generate the DNA genome are distinguishing features of the Hepadnaviridae . In this review, we provide a comprehensive description of HBV biology, summarize the model systems used for studying HBV infections, and highlight potential mechanisms that link a chronic HBV-infection to the development of HCC. For example, the HBV X protein (HBx), a key regulatory HBV protein that is important for HBV replication, is thought to play a cofactor role in the development of HBV-induced HCC, and we highlight the functions of HBx that may contribute to the development of HBV-associated HCC.
-
Nolden, T; Pfaff, F; Nemitz, S; Freuling, C M; Höper, D; Müller, T; Finke, Stefan
2016-04-05
Reverse genetics approaches are indispensable tools for proof of concepts in virus replication and pathogenesis. For negative strand RNA viruses (NSVs) the limited number of infectious cDNA clones represents a bottleneck as clones are often generated from cell culture adapted or attenuated viruses, with limited potential for pathogenesis research. We developed a system in which cDNA copies of complete NSV genomes were directly cloned into reverse genetics vectors by linear-to-linear RedE/T recombination. Rapid cloning of multiple rabies virus (RABV) full length genomes and identification of clones identical to field virus consensus sequence confirmed the approache's reliability. Recombinant viruses were recovered from field virus cDNA clones. Similar growth kinetics of parental and recombinant viruses, preservation of field virus characters in cell type specific replication and virulence in the mouse model were confirmed. Reduced titers after reporter gene insertion indicated that the low level of field virus replication is affected by gene insertions. The flexibility of the strategy was demonstrated by cloning multiple copies of an orthobunyavirus L genome segment. This important step in reverse genetics technology development opens novel avenues for the analysis of virus variability combined with phenotypical characterization of recombinant viruses at a clonal level.
-
Grünvogel, Oliver; Colasanti, Ombretta; Lee, Ji-Young; Klöss, Volker; Belouzard, Sandrine; Reustle, Anna; Esser-Nobis, Katharina; Hesebeck-Brinckmann, Jasper; Mutz, Pascal; Hoffmann, Katrin; Mehrabi, Arianeb; Koschny, Ronald; Vondran, Florian W R; Gotthardt, Daniel; Schnitzler, Paul; Neumann-Haefelin, Christoph; Thimme, Robert; Binder, Marco; Bartenschlager, Ralf; Dubuisson, Jean; Dalpke, Alexander H; Lohmann, Volker
2018-06-01
Hepatitis C virus (HCV) infections most often result in chronic outcomes, although the virus constantly produces replication intermediates, in particular double-stranded RNA (dsRNA), representing potent inducers of innate immunity. We aimed to characterize the fate of HCV dsRNA in hepatocyte cultures to identify mechanisms contributing to viral persistence in presence of an active innate immune response. We analyzed hepatocyte-based culture models for HCV for induction of innate immunity, secretion of virus positive- or negative-strand RNA, and viral replication using different quantification methods and microscopy techniques. Expression of pattern recognition receptors was reconstituted in hepatoma cells by lentiviral transduction. HCV-infected cells secrete substantial amounts of virus positive- and negative-strand RNAs in extracellular vesicles (EVs), toward the apical and basolateral domain of hepatocytes. Secretion of negative-strand RNA was independent from virus production, and viral RNA secreted in EVs contained higher relative amounts of negative-strands, indicating that mostly virus dsRNA is released. A substantial part of viral replication complexes and dsRNA was found in the endosomal compartment and multivesicular bodies, indicating that secretion of HCV replication intermediates is mediated by the exosomal pathway. Block of vesicle release in HCV-positive cells increased intracellular dsRNA levels and increased activation of toll-like receptor 3, inhibiting HCV replication. Using hepatocyte-based culture models for HCV, we found a portion of HCV dsRNA intermediates to be released from infected cells in EVs, which reduces activation of toll-like receptor 3. This represents a novel mechanism how HCV evades host immune responses, potentially contributing to viral persistence. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.
-
Characterization of the replication cycle of the Lymantria dispar nuclear polyhedrosis virus
Christopher I. Riegel; James M. Slavicek
1997-01-01
The life cycle of the Lymantria dispar nuclear polyhedrosis virus (LdMNPV) was characterized through analysis of budded virus (BV) release, the temporal formation of polyhedra, the temporal transcription pattern of representative early, late, and hyper-expressed late genes, and the onset of DNA replication in the Ld652Y cell line. Transcripts from...
-
Huang, Kuan-Ying Arthur; Li, Chris Ka-Fai; Clutterbuck, Elizabeth; Chui, Cecilia; Wilkinson, Tom; Gilbert, Anthony; Oxford, John; Lambkin-Williams, Rob; Lin, Tzou-Yien; McMichael, Andrew J; Xu, Xiao-Ning
2014-05-01
Antibodies play a major role in the protection against influenza virus in human. However, the antibody level is usually short-lived and the cellular mechanisms underlying influenza virus-specific antibody response to acute infection remain unclear. We studied the kinetics and magnitude of influenza virus-specific B-cell and serum antibody responses in relation to virus replication during the course of influenza infection in healthy adult volunteers who were previously seronegative and experimentally infected with seasonal influenza H1N1 A/Brisbane/59/07 virus. Our data demonstrated a robust expansion of the virus-specific antibody-secreting cells (ASCs) and memory B cells in the peripheral blood, which correlated with both the throat viral load and the duration of viral shedding. The ASC response was obviously detected on day 7 post-infection when the virus was completely cleared from nasal samples, and serum hemagglutination-inhibition antibodies were still undetectable. On day 28 postinfection, influenza virus-specific B cells were further identified from the circulating compartment of isotype-switched B cells. Virus-specific ASCs could be the earliest marker of B-cell response to a new flu virus infection, such as H7N9 in humans.
-
Rahman, Masmudur M.; Liu, Jia; Chan, Winnie M.; Rothenburg, Stefan; McFadden, Grant
2013-01-01
Myxoma virus (MYXV)-encoded protein M029 is a member of the poxvirus E3 family of dsRNA-binding proteins that antagonize the cellular interferon signaling pathways. In order to investigate additional functions of M029, we have constructed a series of targeted M029-minus (vMyx-M029KO and vMyx-M029ID) and V5-tagged M029 MYXV. We found that M029 plays a pivotal role in determining the cellular tropism of MYXV in all mammalian cells tested. The M029-minus viruses were able to replicate only in engineered cell lines that stably express a complementing protein, such as vaccinia E3, but underwent abortive or abated infection in all other tested mammalian cell lines. The M029-minus viruses were dramatically attenuated in susceptible host European rabbits and caused no observable signs of myxomatosis. Using V5-tagged M029 virus, we observed that M029 expressed as an early viral protein is localized in both the nuclear and cytosolic compartments in virus-infected cells, and is also incorporated into virions. Using proteomic approaches, we have identified Protein Kinase R (PKR) and RNA helicase A (RHA)/DHX9 as two cellular binding partners of M029 protein. In virus-infected cells, M029 interacts with PKR in a dsRNA-dependent manner, while binding with DHX9 was not dependent on dsRNA. Significantly, PKR knockdown in human cells rescued the replication defect of the M029-knockout viruses. Unexpectedly, this rescue of M029-minus virus replication by PKR depletion could then be reversed by RHA/DHX9 knockdown in human monocytic THP1 cells. This indicates that M029 not only inhibits generic PKR anti-viral pathways, but also binds and conscripts RHA/DHX9 as a pro-viral effector to promote virus replication in THP1 cells. Thus, M029 is a critical host range and virulence factor for MYXV that is required for replication in all mammalian cells by antagonizing PKR-mediated anti-viral functions, and also conscripts pro-viral RHA/DHX9 to promote viral replication specifically in myeloid cells. PMID:23853588
-
Moon, Ho-Jin; Nikapitiya, Chamilani; Lee, Hyun-Cheol; Park, Min-Eun; Kim, Jae-Hoon; Kim, Tae-Hwan; Yoon, Ji-Eun; Cho, Won-Kyung; Ma, Jin Yeul; Kim, Chul-Joong; Jung, Jae U; Lee, Jong-Soo
2017-07-07
The antiviral activities of synthesized Kα2-helix peptide, which was derived from the viral FLICE-like inhibitor protein (vFLIP) of Kaposi's sarcoma-associated herpesvirus (KSHV), against influenza A virus (IAV) were investigated in vitro and in vivo, and mechanisms of action were suggested. In addition to the robust autophagy activity of the Kα2-helix peptide, the present study showed that treatment with the Kα2 peptide fused with the TAT peptide significantly inhibited IAV replication and transmission. Moreover, TAT-Kα2 peptide protected the mice, that were challenged with lethal doses of highly pathogenic influenza A H5N1 or H1N1 viruses. Mechanistically, we found that TAT-Kα2 peptide destabilized the viral membranes, depending on their lipid composition of the viral envelop. In addition to IAV, the Kα2 peptide inhibited infections with enveloped viruses, such as Vesicular Stomatitis Virus (VSV) and Respiratory Syncytial Virus (RSV), without cytotoxicity. These results suggest that TAT-Kα2 peptide is a potential antiviral agent for controlling emerging or re-emerging enveloped viruses, particularly diverse subtypes of IAVs.
-
Du, Zhi-Qiang; Lan, Jiang-Feng; Weng, Yu-Ding; Zhao, Xiao-Fan; Wang, Jin-Xing
2013-07-01
BAX inhibitor-1 (BI-1) was originally described as an anti-apoptotic protein in both animal and plant cells. BI-1 overexpression suppresses ER stress-induced apoptosis in animal cells. Inhibition of BI-1 activity could induce the cell death in mammals and plants. However, the function of BI-1 in crustacean immunity was unclear. In this paper, the full-length cDNA of a BI-1 protein in red swamp crayfish, Procambarus clarkii (PcBI-1) was cloned and its expression profiles in normal and infected crayfish were analyzed. The results showed that PcBI-1 was expressed in hemocytes, heart, hepatopancreas, gills, stomach, and intestines of the crayfish and was upregulated after challenged with Vibrio anguillarum and with white spot syndrome virus (WSSV). To determine the function of PcBI-1 in the innate immunity of the crayfish, the RNA interference against PcBI-1 was performed and the results indicated the hemocyte programmed cell death rate was increased significantly and WSSV replication was declined after PcBI-1 knocked down. Altogether, PcBI-1 plays an anti-apoptotic role, wherein high PcBI-1 expression suppresses programmed cell death, which is beneficial for WSSW replication in crayfish. Copyright © 2013 Elsevier Ltd. All rights reserved.
-
Pitzalis, Nicolas; Heinlein, Manfred
2017-12-18
The infection of plants by viruses depends on cellular mechanisms that support the replication of the viral genomes, and the cell-to-cell and systemic movement of the virus via plasmodesmata (PD) and the connected phloem. While the propagation of some viruses requires the conventional endoplasmic reticulum (ER)-Golgi pathway, others replicate and spread between cells in association with the ER and are independent of this pathway. Using selected viruses as examples, this review re-examines the involvement of membranes and the cytoskeleton during virus infection and proposes potential roles of class VIII myosins and membrane-tethering proteins in controlling viral functions at specific ER subdomains, such as cortical microtubule-associated ER sites, ER-plasma membrane contact sites, and PD. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.
-
NASA Astrophysics Data System (ADS)
da Costa, Xavier J.; Jones, Cheryl A.; Knipe, David M.
1999-06-01
An effective vaccine for genital herpes has been difficult to achieve because of the limited efficacy of subunit vaccines and the safety concerns about live viruses. As an alternative approach, mutant herpes simplex virus strains that are replication-defective can induce protective immunity. To increase the level of safety and to prove that replication was not needed for immunization, we constructed a mutant herpes simplex virus 2 strain containing two deletion mutations, each of which eliminated viral replication. The double-mutant virus induces protective immunity that can reduce acute viral shedding and latent infection in a mouse genital model, but importantly, the double-mutant virus shows a phenotypic defect in latent infection. This herpes vaccine strain, which is immunogenic but has defects in both productive and latent infection, provides a paradigm for the design of vaccines and vaccine vectors for other sexually transmitted diseases, such as AIDS.
-
Mühlberger, Elke; Lötfering, Beate; Klenk, Hans-Dieter; Becker, Stephan
1998-01-01
This paper describes the first reconstituted replication system established for a member of the Filoviridae, Marburg virus (MBGV). MBGV minigenomes containing the leader and trailer regions of the MBGV genome and the chloramphenicol acetyltransferase (CAT) gene were constructed. In MBGV-infected cells, these minigenomes were replicated and encapsidated and could be passaged. Unlike most other members of the order Mononegavirales, filoviruses possess four proteins presumed to be components of the nucleocapsid (NP, VP35, VP30, and L). To determine the protein requirements for replication and transcription, a reverse genetic system was established for MBGV based on the vaccinia virus T7 expression system. Northern blot analysis of viral RNA revealed that three nucleocapsid proteins (NP, VP35, and L) were essential and sufficient for transcription as well as replication and encapsidation. These data indicate that VP35, rather than VP30, is the functional homologue of rhabdo- and paramyxovirus P proteins. The reconstituted replication system was profoundly affected by the NP-to-VP35 expression ratio. To investigate whether CAT gene expression was achieved entirely by mRNA or in part by full-length plus-strand minigenomes, a copy-back minireplicon containing the CAT gene but lacking MBGV-specific transcriptional start sites was employed in the artificial replication system. This construct was replicated without accompanying CAT activity. It was concluded that the CAT activity reflected MBGV-specific transcription and not replication. PMID:9765419
-
Prasanth, K Reddisiva; Barajas, Daniel; Nagy, Peter D
2015-03-01
RNA viruses co-opt a large number of cellular proteins that affect virus replication and, in some cases, viral genetic recombination. RNA recombination helps viruses in an evolutionary arms race with the host's antiviral responses and adaptation of viruses to new hosts. Tombusviruses and a yeast model host are used to identify cellular factors affecting RNA virus replication and RNA recombination. In this study, we have examined the role of the conserved Rpn11p metalloprotease subunit of the proteasome, which couples deubiquitination and degradation of proteasome substrates, in tombusvirus replication and recombination in Saccharomyces cerevisiae and plants. Depletion or mutations of Rpn11p lead to the rapid formation of viral RNA recombinants in combination with reduced levels of viral RNA replication in yeast or in vitro based on cell extracts. Rpn11p interacts with the viral replication proteins and is recruited to the viral replicase complex (VRC). Analysis of the multifunctional Rpn11p has revealed that the primary role of Rpn11p is to act as a "matchmaker" that brings the viral p92(pol) replication protein and the DDX3-like Ded1p/RH20 DEAD box helicases into VRCs. Overexpression of Ded1p can complement the defect observed in rpn11 mutant yeast by reducing TBSV recombination. This suggests that Rpn11p can suppress tombusvirus recombination via facilitating the recruitment of the cellular Ded1p helicase, which is a strong suppressor of viral recombination, into VRCs. Overall, this work demonstrates that the co-opted Rpn11p, which is involved in the assembly of the functional proteasome, also functions in the proper assembly of the tombusvirus VRCs. RNA viruses evolve rapidly due to genetic changes based on mutations and RNA recombination. Viral genetic recombination helps viruses in an evolutionary arms race with the host's antiviral responses and facilitates adaptation of viruses to new hosts. Cellular factors affect viral RNA recombination, although the role of the host in virus evolution is still understudied. In this study, we used a plant RNA virus, tombusvirus, to examine the role of a cellular proteasomal protein, called Rpn11, in tombusvirus recombination in a yeast model host, in plants, and in vitro. We found that the cellular Rpn11 is subverted for tombusvirus replication and Rpn11 has a proteasome-independent function in facilitating viral replication. When the Rpn11 level is knocked down or a mutated Rpn11 is expressed, then tombusvirus RNA goes through rapid viral recombination and evolution. Taken together, the results show that the co-opted cellular Rpn11 is a critical host factor for tombusviruses by regulating viral replication and genetic recombination. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
-
Kloc, Anna; Diaz-San Segundo, Fayna; Schafer, Elizabeth A; Rai, Devendra K; Kenney, Mary; de Los Santos, Teresa; Rieder, Elizabeth
2017-12-01
The S fragment of the FMDV 5' UTR is predicted to fold into a long stem-loop structure and it has been implicated in virus-host protein interactions. In this study, we report the minimal S fragment sequence required for virus viability and show a direct correlation between the extent of the S fragment deletion mutations and attenuated phenotypes. Furthermore, we provide novel insight into the role of the S fragment in modulating the host innate immune response. Importantly, in an FMDV mouse model system, all animals survive the inoculation with the live A 24 FMDV-S 4 mutant, containing a 164 nucleotide deletion in the upper S fragment loop, at a dose 1000 higher than the one causing lethality by parental A 24 FMDV, indicating that the A 24 FMDV-S 4 virus is highly attenuated in vivo. Additionally, mice exposed to high doses of live A 24 FMDV-S 4 virus are fully protected when challenged with parental A 24 FMDV virus. Published by Elsevier Inc.
-
Ermak, G; Paszkowski, U; Wohlmuth, M; Scheid, O M; Paszkowski, J
1993-01-01
Extrachromosomally replicating viral DNA is usually free of cytosine methylation and viral templates methylated in vitro are poor substrates when used in replication assays. We have investigated the mechanism of inhibition of viral replication by DNA methylation using as a model the DNA A of African cassava mosaic virus. We have constructed two component helper systems which allow for separation of the transcriptional inhibition of viral genes necessary for replication from replication inhibition due to altered interaction between the replication complex and methylated viral DNA. Our results suggest that methylation-mediated reduction of viral replication is due to both repression mechanisms and that this provides two independent selection pressures for the maintenance of methylation-free replicons in infected cells. Images PMID:7688453
-
Oxidative stress favours herpes virus infection in vertebrates: a meta-analysis.
Sebastiano, Manrico; Chastel, Olivier; de Thoisy, Benoît; Eens, Marcel; Costantini, David
2016-08-01
Herpes viruses are responsible for a variety of pathological effects in humans and in both wild and domestic animals. One mechanism that has been proposed to facilitate replication and activity of herpes viruses is oxidative stress (OS). We used meta-analytical techniques to test the hypotheses that (1) herpes virus infection causes OS and (2) supplementation of antioxidants reduces virus load, indicating that replication is favoured by a state of OS. Results based on studies on mammals, including humans, and birds show that (1) OS is indeed increased by herpes virus infection across multiple tissues and species, (2) biomarkers of OS may change differently between tissues, and (3) the effect size does not differ among different virus strains. In addition, the increase of oxidative damage in blood (tissue commonly available in ecological studies) was similar to that in the tissues most sensitive to the herpes virus. Our results also show that administration of antioxidants reduces virus yield, indicating that a condition of OS is favorable for the viral replication. In addition, some antioxidants may be more efficient than others in reducing herpes virus yield. Our results point to a potential mechanism linking herpes virus infection to individual health status.
-
Evolutionary dynamics of giant viruses and their virophages.
Wodarz, Dominik
2013-07-01
Giant viruses contain large genomes, encode many proteins atypical for viruses, replicate in large viral factories, and tend to infect protists. The giant virus replication factories can in turn be infected by so called virophages, which are smaller viruses that negatively impact giant virus replication. An example is Mimiviruses that infect the protist Acanthamoeba and that are themselves infected by the virophage Sputnik. This study examines the evolutionary dynamics of this system, using mathematical models. While the models suggest that the virophage population will evolve to increasing degrees of giant virus inhibition, it further suggests that this renders the virophage population prone to extinction due to dynamic instabilities over wide parameter ranges. Implications and conditions required to avoid extinction are discussed. Another interesting result is that virophage presence can fundamentally alter the evolutionary course of the giant virus. While the giant virus is predicted to evolve toward increasing its basic reproductive ratio in the absence of the virophage, the opposite is true in its presence. Therefore, virophages can not only benefit the host population directly by inhibiting the giant viruses but also indirectly by causing giant viruses to evolve toward weaker phenotypes. Experimental tests for this model are suggested.
-
Evolutionary dynamics of giant viruses and their virophages
Wodarz, Dominik
2013-01-01
Giant viruses contain large genomes, encode many proteins atypical for viruses, replicate in large viral factories, and tend to infect protists. The giant virus replication factories can in turn be infected by so called virophages, which are smaller viruses that negatively impact giant virus replication. An example is Mimiviruses that infect the protist Acanthamoeba and that are themselves infected by the virophage Sputnik. This study examines the evolutionary dynamics of this system, using mathematical models. While the models suggest that the virophage population will evolve to increasing degrees of giant virus inhibition, it further suggests that this renders the virophage population prone to extinction due to dynamic instabilities over wide parameter ranges. Implications and conditions required to avoid extinction are discussed. Another interesting result is that virophage presence can fundamentally alter the evolutionary course of the giant virus. While the giant virus is predicted to evolve toward increasing its basic reproductive ratio in the absence of the virophage, the opposite is true in its presence. Therefore, virophages can not only benefit the host population directly by inhibiting the giant viruses but also indirectly by causing giant viruses to evolve toward weaker phenotypes. Experimental tests for this model are suggested. PMID:23919155
-
Huang, Ying-Wen; Hu, Chung-Chi; Lin, Na-Sheng; Hsu, Yau-Heiu
2010-01-01
Satellite RNAs (satRNAs) and satellite viruses depend on the replicase complexes provided by their cognate helper viruses and host plants for replication, pretending that they are part of the viral genomes. Although satRNAs and satellite viruses do not share significant nucleotide sequence similarity with the helper viruses, the essential cis-acting elements recognized by the replicase complexes must reside on their genomes, acting as the mimicry for the molecular pretenders. By understanding how this molecular mimicry deceives the helper viruses into supporting the satellites, a significant amount of knowledge of the basic requirements and mechanisms for replication of viruses and satellites has been obtained. Here we review the recent advances in understanding the effects of the cis elements at the termini of satRNAs and satellite viruses on their accumulation. Several well-characterized satellite/helper virus systems, representing the non-coding short satRNAs, mRNA-type long satRNAs, circular satRNAs and satellite viruses, are compared and contrasted. It is concluded that different satellites may adopt different strategies to exploit the replication/transcription/translation machineries of their helper viruses, and different mimicries may be implemented by the same molecular pretender for different biological functions.
-
Broadbent, Andrew J; Santos, Celia P; Godbout, Rachel A; Subbarao, Kanta
2014-11-01
Live attenuated influenza vaccines in the United States are derived from a human virus that is temperature sensitive (ts), characterized by restricted (≥ 100-fold) replication at 39 °C. The ts genetic signature (ts sig) has been mapped to 5 loci in 3 genes: PB1 (391 E, 581 G, and 661 T), PB2 (265 S), and NP (34 G). However, when transferred into avian and swine influenza viruses, only partial ts and attenuation phenotypes occur. To investigate the reason for this, we introduced the ts sig into the human origin virus A/WSN/33 (WSN), the avian-origin virus A/Vietnam/1203/04 (VN04), and the swine origin triple-reassortant 2009 pandemic H1N1 virus A/California/07/2009 (CA07), which contains gene segments from human, avian, and swine viruses. The VN04(ts sig) and CA07(ts sig) viruses replicated efficiently in Madin-Darby canine kidney (MDCK) cells at 39 °C, but the replication of WSN(ts sig) was restricted ≥ 100-fold compared to that at 33 °C. Reassortant CA07(ts sig) viruses were generated with individual polymerase gene segments from WSN, and vice versa. Only ts sig viruses with a PB2 gene segment derived from WSN were restricted in replication ≥ 100-fold at 39 °C. In ferrets, the CA07(ts sig) virus replicated in the upper and lower respiratory tract, but the replication of a reassortant CA07(ts sig) virus with a WSN PB2 gene was severely restricted in the lungs. Taken together, these data suggest that the origin of the PB2 gene segment influences the ts phenotype in vitro and attenuation in vivo. This could have implications for the design of novel live vaccines against animal origin influenza viruses. Live attenuated influenza vaccines (LAIVs) on temperature-sensitive (ts) backbones derived from animal origin influenza viruses are being sought for use in the poultry and swine industries and to protect people against animal origin influenza. However, inserting the ts genetic signature from a licensed LAIV backbone fails to fully attenuate these viruses. Our data indicate this is associated with the presence of a PB2 gene segment derived from an avian influenza virus. We show that a reassortant 2009 pandemic H1N1 virus with the ts signature from a licensed LAIV donor virus is ts in vitro and attenuated in vivo when the PB2 gene is derived from a human origin virus but not from an avian virus. Our study provides information that could benefit the rational design of alternative LAIV backbones against animal origin influenza viruses. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
-
Broadbent, Andrew J.; Santos, Celia P.; Godbout, Rachel A.
2014-01-01
ABSTRACT Live attenuated influenza vaccines in the United States are derived from a human virus that is temperature sensitive (ts), characterized by restricted (≥100-fold) replication at 39°C. The ts genetic signature (ts sig) has been mapped to 5 loci in 3 genes: PB1 (391E, 581G, and 661T), PB2 (265S), and NP (34G). However, when transferred into avian and swine influenza viruses, only partial ts and attenuation phenotypes occur. To investigate the reason for this, we introduced the ts sig into the human origin virus A/WSN/33 (WSN), the avian-origin virus A/Vietnam/1203/04 (VN04), and the swine origin triple-reassortant 2009 pandemic H1N1 virus A/California/07/2009 (CA07), which contains gene segments from human, avian, and swine viruses. The VN04ts sig and CA07ts sig viruses replicated efficiently in Madin-Darby canine kidney (MDCK) cells at 39°C, but the replication of WSNts sig was restricted ≥100-fold compared to that at 33°C. Reassortant CA07ts sig viruses were generated with individual polymerase gene segments from WSN, and vice versa. Only ts sig viruses with a PB2 gene segment derived from WSN were restricted in replication ≥100-fold at 39°C. In ferrets, the CA07ts sig virus replicated in the upper and lower respiratory tract, but the replication of a reassortant CA07ts sig virus with a WSN PB2 gene was severely restricted in the lungs. Taken together, these data suggest that the origin of the PB2 gene segment influences the ts phenotype in vitro and attenuation in vivo. This could have implications for the design of novel live vaccines against animal origin influenza viruses. IMPORTANCE Live attenuated influenza vaccines (LAIVs) on temperature-sensitive (ts) backbones derived from animal origin influenza viruses are being sought for use in the poultry and swine industries and to protect people against animal origin influenza. However, inserting the ts genetic signature from a licensed LAIV backbone fails to fully attenuate these viruses. Our data indicate this is associated with the presence of a PB2 gene segment derived from an avian influenza virus. We show that a reassortant 2009 pandemic H1N1 virus with the ts signature from a licensed LAIV donor virus is ts in vitro and attenuated in vivo when the PB2 gene is derived from a human origin virus but not from an avian virus. Our study provides information that could benefit the rational design of alternative LAIV backbones against animal origin influenza viruses. PMID:25122786
-
Gowen, Brian B; Bailey, Kevin W; Scharton, Dionna; Vest, Zachery; Westover, Jonna B; Skirpstunas, Ramona; Ikegami, Tetsuro
2013-05-01
Rift Valley fever virus (RVFV) causes severe disease in humans and livestock. There are currently no approved antivirals or vaccines for the treatment or prevention of RVF disease in humans. A major virulence factor of RVFV is the NSs protein, which inhibits host transcription including the interferon (IFN)-β gene and promotes the degradation of dsRNA-dependent protein kinase, PKR. We analyzed the efficacy of the live-attenuated MP-12 vaccine strain and MP-12 variants that lack the NSs protein as post-exposure vaccinations. Although parental MP-12 failed to elicit a protective effect in mice challenged with wild-type (wt) RVFV by the intranasal route, significant protection was demonstrated by vaccination with MP-12 strains lacking NSs when they were administered at 20-30 min post-exposure. Viremia and virus replication in liver, spleen and brain were also inhibited by post-exposure vaccination with MP-12 lacking NSs. The protective effect was mostly lost when vaccination was delayed 6 or 24 h after intranasal RVFV challenge. When mice were challenged subcutaneously, efficacy of MP-12 lacking NSs was diminished, most likely due to more rapid dissemination of wt RVFV. Our findings suggest that post-exposure vaccination with MP-12 lacking NSs may be developed as a novel post-exposure treatment to prevent RVF. Copyright © 2013 Elsevier B.V. All rights reserved.
-
Parida, Satya; Anderson, John; Cox, Sarah J; Barnett, Paul V; Paton, David J
2006-02-20
A serotype-specific ELISA was developed to detect foot-and-mouth disease virus (FMDV) specific IgA antibody in the saliva of cattle, and the method was evaluated for its feasibility in detecting serotype O FMDV carrier animals, particularly amongst vaccinated cattle that had subsequently become sub-clinically infected. For this purpose, saliva samples were collected from naïve cattle (n = 173), FMDV challenged cattle (n = 10), FMDV vaccinated cattle (n = 40) and FMDV vaccinated-and-challenged cattle (n = 40). A subset of 29 cattle was sampled for 105-168 days after challenge. The FMDV infection status of each of the cattle was determined by virus isolation and RT-PCR tests on oesophago-pharyngeal fluids and the ability of the IgA test to detect viral infection and persistence was compared to an ELISA for the detection of serum antibodies against the 3ABC non-structural proteins of FMDV. Eleven out of twelve vaccinated cattle that were shown to be persistently infected with FMDV up to or beyond 28 days post challenge, were also detected by the IgA test on saliva. With some modification and further validation, this test could be useful in post-vaccination surveillance to help confirm the absence of sub-clinical infection in order to regain the FMD-free status of a region or country.
-
Starkey, Jason; Mellinger, Erica; Zhang, Dan; Chadha, Pooja; Carmichael, Jillian
2017-01-01
ABSTRACT The initial goal of this study was to reexamine the requirement of UL21 for herpes simplex virus 1 (HSV-1) replication. Previous studies suggested that UL21 is dispensable for replication in cell cultures, but a recent report on HSV-2 challenges those findings. As was done for the HSV-2 study, a UL21-null virus was made and propagated on complementing cells to discourage selection of compensating mutations. This HSV-1 mutant was able to replicate in noncomplementing cells, even at a low multiplicity of infection (MOI), though a reduction in titer was observed. Also, increased proportions of empty capsids were observed in the cytoplasm, suggesting a role for UL21 in preventing their exit from the nucleus. Surprisingly, passage of the null mutant resulted in rapid outgrowth of syncytial (Syn) variants. This was unexpected because UL21 has been shown to be required for the Syn phenotype. However, earlier experiments made use of only the A855V syncytial mutant of glycoprotein B (gB), and the Syn phenotype can also be produced by substitutions in glycoprotein K (gK), UL20, and UL24. Sequencing of the syncytial variants revealed mutations in the gK locus, but UL21 was shown to be dispensable for UL20Syn and UL24Syn. To test whether UL21 is needed only for the A855V mutant, additional gBSyn derivatives were examined in the context of the null virus, and all produced lytic rather than syncytial sites of infection. Thus, UL21 is required only for the gBSyn phenotype. This is the first example of a differential requirement for a viral protein across the four syn loci. IMPORTANCE UL21 is conserved among alphaherpesviruses, but its role is poorly understood. This study shows that HSV-1 can replicate without UL21, although the virus titers are greatly reduced. The null virus had greater proportions of empty (DNA-less) capsids in the cytoplasm of infected cells, suggesting that UL21 may play a role in retaining them in the nucleus. This is consistent with reports showing UL21 to be capsid associated and localized to the nuclei of infected cells. UL21 also appears to be needed for viral membrane activities. It was found to be required for virus-mediated cell fusion, but only for mutants that harbor syncytial mutations in gB (not variants of gK, UL20, or UL24). The machinery needed for syncytial formation is similar to that needed for direct spread of the virus through cell junctions, and these studies show that UL21 is required for cell-to-cell spread even in the absence of syncytial mutations. PMID:28794039
-
Loo, Christopher P; Snyder, Christopher M; Hill, Ann B
2017-01-01
Increasing amounts of pathogen replication usually lead to a proportionate increase in size and effector differentiation of the CD8 + T cell response, which is attributed to increased Ag and inflammation. Using a murine CMV that is highly sensitive to the antiviral drug famciclovir to modulate virus replication, we found that increased virus replication drove increased effector CD8 + T cell differentiation, as expected. Paradoxically, however, increased virus replication dramatically decreased the size of the CD8 + T cell response to two immunodominant epitopes. The decreased response was due to type I IFN-dependent depletion of conventional dendritic cells and could be reproduced by specific depletion of dendritic cells from day 2 postinfection or by sterile induction of type I IFN. Increased virus replication and type I IFN specifically inhibited the response to two immunodominant epitopes that are known to be dependent on Ag cross-presented by DCs, but they did not inhibit the response to "inflationary" epitopes whose responses can be sustained by infected nonhematopoietic cells. Our results show that type I IFN can suppress CD8 + T cell responses to cross-presented Ag by depleting cross-presenting conventional dendritic cells. Copyright © 2016 by The American Association of Immunologists, Inc.
-
Legrand, Nicolas; van der Velden, Gisela J.; Fang, Raphaël Ho Tsong; Douaisi, Marc; Weijer, Kees; Das, Atze T.; Blom, Bianca; Uittenbogaart, Christel H.; Berkhout, Ben
2012-01-01
A novel genetic approach for the control of virus replication was used for the design of a conditionally replicating human immunodeficiency virus (HIV) variant, HIV-rtTA. HIV-rtTA gene expression and virus replication are strictly dependent on the presence of a non-toxic effector molecule, doxycycline (dox), and thus can be turned on and off at will in a graded and reversible manner. The in vivo replication capacity, pathogenicity and genetic stability of this HIV-rtTA variant were evaluated in a humanized mouse model of haematopoiesis that harbours lymphoid and myeloid components of the human immune system (HIS). Infection of dox-fed BALB Rag/γc HIS (BRG-HIS) mice with HIV-rtTA led to the establishment of a productive infection without CD4+ T-cell depletion. The virus did not show any sign of escape from dox control for up to 10 weeks after the onset of infection. No reversion towards a functional Tat–transactivating responsive (TAR) RNA element axis was observed, confirming the genetic stability of the HIV-rtTA variant in vivo. These results demonstrate the proof of concept that HIV-rtTA replicates efficiently in vivo. HIV-rtTA is a promising tool for fundamental research to study virus–host interactions in vivo in a controlled fashion. PMID:22647372
-
Isolation of midgut escape mutants of two American genotype dengue 2 viruses from Aedes aegypti
2013-01-01
Background Several studies have shown that American genotype dengue 2 viruses (DENV2) have reduced viral fitness in the mosquito vector, Aedes aegypti, compared to other DENV2 genotypes. Diminished replication efficiency or inability to efficiently traverse membrane barriers encompassing organs such as the midgut or salivary glands are considered major factors negatively impacting viral fitness in the mosquito. Results We analyzed the vector competence of Ae. aegypti for two American DENV2 strains, QR94 and PR159 originating from Mexico and Puerto-Rico, respectively. Both strains infected mosquito midguts following acquisition of infectious bloodmeals. However, DENV2-QR94 and DENV2-PR159 poorly disseminated from the midgut at 7 or 14 days post-bloodmeal (pbm). We detected one virus isolate, EM33, among 31 DENV2-QR94 infected mosquitoes, and one isolate, EM41, among 121 DENV2-PR159 infected mosquitoes, generating high virus titers in mosquito carcasses at 7 days pbm. In oral challenge experiments, EM33 and EM41 showed midgut dissemination rates of 40-50%. Replication efficiency of EM41 in secondary mosquito tissue was similar to that of a dissemination-competent control strain, whereas the replication efficiency of EM33 was significantly lower than that of the control virus. The genome sequence of DENV2-QR94 encoded seven unique amino acids (aa), which were not found in 100 of the most closely related DENV2 strains. EM33 had one additional aa change, E202K, in the E protein. DENV2-PR159 encoded four unique aa residues, one of them E202K, whereas EM41 had two additional aa substitutions, Q77E in the E protein and E93D in NS3. Conclusions Our results indicate that the midgut of Ae. aegypti acts as a selective sieve for DENV2 in which genetically distinct, dissemination-competent virus variants are rapidly selected from the viral quasispecies to be transmitted to vertebrates. PMID:23937713
-
Cancer Terminator Viruses and Approaches for Enhancing Therapeutic Outcomes
Das, Swadesh K.; Sarkar, Siddik; Dash, Rupesh; Dent, Paul; Wang, Xiang-Yang; Sarkar, Devanand; Fisher, Paul B.
2015-01-01
No single or combinatorial therapeutic approach has proven effective in decreasing morbidity or engendering a cure of metastatic cancer. In principle, conditionally replication-competent adenoviruses that induce tumor oncolysis through cancer-specific replication hold promise for cancer therapy. However, a single-agent approach may not be adequate to completely eradicate cancer in a patient because most cancers arise from abnormalities in multiple genetic and signal transduction pathways and targeting disseminated metastases is difficult to achieve. Based on these considerations, a novel class of cancer destroying adenoviruses have been produced, cancer terminator viruses (CTVs), in which cancer-specific replication is controlled by the progression-elevated gene-3 promoter and replicating viruses produce a second transgene encoding an apoptosis-inducing and immunomodulatory cytokine, either melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24) or interferon-γ. This review focuses on these viruses and ways to improve their delivery systemically and enhance their therapeutic efficacy. PMID:23021240
-
Sequential structures provide insights into the fidelity of RNA replication.
Ferrer-Orta, Cristina; Arias, Armando; Pérez-Luque, Rosa; Escarmís, Cristina; Domingo, Esteban; Verdaguer, Nuria
2007-05-29
RNA virus replication is an error-prone event caused by the low fidelity of viral RNA-dependent RNA polymerases. Replication fidelity can be decreased further by the use of mutagenic ribonucleoside analogs to a point where viral genetic information can no longer be maintained. For foot-and-mouth disease virus, the antiviral analogs ribavirin and 5-fluorouracil have been shown to be mutagenic, contributing to virus extinction through lethal mutagenesis. Here, we report the x-ray structure of four elongation complexes of foot-and-mouth disease virus polymerase 3D obtained in presence of natural substrates, ATP and UTP, or mutagenic nucleotides, ribavirin triphosphate and 5-fluorouridine triphosphate with different RNAs as template-primer molecules. The ability of these complexes to synthesize RNA in crystals allowed us to capture different successive replication events and to define the critical amino acids involved in (i) the recognition and positioning of the incoming nucleotide or analog; (ii) the positioning of the acceptor base of the template strand; and (iii) the positioning of the 3'-OH group of the primer nucleotide during RNA replication. The structures identify key interactions involved in viral RNA replication and provide insights into the molecular basis of the low fidelity of viral RNA polymerases.
-
Rabies viruses leader RNA interacts with host Hsc70 and inhibits virus replication
Zhang, Ran; Liu, Chuangang; Cao, Yunzi; Jamal, Muhammad; Chen, Xi; Zheng, Jinfang; Li, Liang; You, Jing; Zhu, Qi; Liu, Shiyong; Dai, Jinxia; Cui, Min; Fu, Zhen F.; Cao, Gang
2017-01-01
Viruses have been shown to be equipped with regulatory RNAs to evade host defense system. It has long been known that rabies virus (RABV) transcribes a small regulatory RNA, leader RNA (leRNA), which mediates the transition from viral RNA transcription to replication. However, the detailed molecular mechanism remains enigmatic. In the present study, we determined the genetic architecture of RABV leRNA and demonstrated its inhibitory effect on replication of wild-type rabies, DRV-AH08. The RNA immunoprecipitation results suggest that leRNA inhibits RABV replication via interfering the binding of RABV nucleoprotein with genomic RNA. Furthermore, we identified heat shock cognate 70 kDa protein (Hsc70) as a leRNA host cellular interacting protein, of which the expression level was dynamically regulated by RABV infection. Notably, our data suggest that Hsc70 was involved in suppressing RABV replication by leader RNA. Finally, our experiments imply that leRNA might be potentially useful as a novel drug in rabies post-exposure prophylaxis. Together, this study suggested leRNA in concert with its host interacting protein Hsc70, dynamically down-regulate RABV replication. PMID:28388579
-
Nougairede, Antoine; De Fabritus, Lauriane; Aubry, Fabien; Gould, Ernest A; Holmes, Edward C; de Lamballerie, Xavier
2013-02-01
Large-scale codon re-encoding represents a powerful method of attenuating viruses to generate safe and cost-effective vaccines. In contrast to specific approaches of codon re-encoding which modify genome-scale properties, we evaluated the effects of random codon re-encoding on the re-emerging human pathogen Chikungunya virus (CHIKV), and assessed the stability of the resultant viruses during serial in cellulo passage. Using different combinations of three 1.4 kb randomly re-encoded regions located throughout the CHIKV genome six codon re-encoded viruses were obtained. Introducing a large number of slightly deleterious synonymous mutations reduced the replicative fitness of CHIKV in both primate and arthropod cells, demonstrating the impact of synonymous mutations on fitness. Decrease of replicative fitness correlated with the extent of re-encoding, an observation that may assist in the modulation of viral attenuation. The wild-type and two re-encoded viruses were passaged 50 times either in primate or insect cells, or in each cell line alternately. These viruses were analyzed using detailed fitness assays, complete genome sequences and the analysis of intra-population genetic diversity. The response to codon re-encoding and adaptation to culture conditions occurred simultaneously, resulting in significant replicative fitness increases for both re-encoded and wild type viruses. Importantly, however, the most re-encoded virus failed to recover its replicative fitness. Evolution of these viruses in response to codon re-encoding was largely characterized by the emergence of both synonymous and non-synonymous mutations, sometimes located in genomic regions other than those involving re-encoding, and multiple convergent and compensatory mutations. However, there was a striking absence of codon reversion (<0.4%). Finally, multiple mutations were rapidly fixed in primate cells, whereas mosquito cells acted as a brake on evolution. In conclusion, random codon re-encoding provides important information on the evolution and genetic stability of CHIKV viruses and could be exploited to develop a safe, live attenuated CHIKV vaccine.
-
Noumeavirus replication relies on a transient remote control of the host nucleus
Fabre, Elisabeth; Jeudy, Sandra; Santini, Sébastien; Legendre, Matthieu; Trauchessec, Mathieu; Couté, Yohann; Claverie, Jean-Michel; Abergel, Chantal
2017-01-01
Acanthamoeba are infected by a remarkable diversity of large dsDNA viruses, the infectious cycles of which have been characterized using genomics, transcriptomics and electron microscopy. Given their gene content and the persistence of the host nucleus throughout their infectious cycle, the Marseilleviridae were initially assumed to fully replicate in the cytoplasm. Unexpectedly, we find that their virions do not incorporate the virus-encoded transcription machinery, making their replication nucleus-dependent. However, instead of delivering their DNA to the nucleus, the Marseilleviridae initiate their replication by transiently recruiting the nuclear transcription machinery to their cytoplasmic viral factory. The nucleus recovers its integrity after becoming leaky at an early stage. This work highlights the importance of virion proteomic analyses to complement genome sequencing in the elucidation of the replication scheme and evolution of large dsDNA viruses. PMID:28429720
-
Pantin-Jackwood, Mary; Guzman, Sofia G.; Ricardez, Yadira; Spackman, Erica; Bertran, Kateri; Suarez, David L.; Swayne, David E.
2013-01-01
In June of 2012, an H7N3 highly pathogenic avian influenza (HPAI) virus was identified as the cause of a severe disease outbreak in commercial laying chicken farms in Mexico. The purpose of this study was to characterize the Mexican 2012 H7N3 HPAI virus (A/chicken/Jalisco/CPA1/2012) and determine the protection against the virus conferred by different H7 inactivated vaccines in chickens. Both adult and young chickens intranasally inoculated with the virus became infected and died at between 2 and 4 days postinoculation (p.i.). High virus titers and viral replication in many tissues were demonstrated at 2 days p.i. in infected birds. The virus from Jalisco, Mexico, had high sequence similarity of greater than 97% to the sequences of wild bird viruses from North America in all eight gene segments. The hemagglutinin gene of the virus contained a 24-nucleotide insert at the hemagglutinin cleavage site which had 100% sequence identity to chicken 28S rRNA, suggesting that the insert was the result of nonhomologous recombination with the host genome. For vaccine protection studies, both U.S. H7 low-pathogenic avian influenza (LPAI) viruses and a 2006 Mexican H7 LPAI virus were tested as antigens in experimental oil emulsion vaccines and injected into chickens 3 weeks prior to challenge. All H7 vaccines tested provided ≥90% protection against clinical disease after challenge and decreased the number of birds shedding virus and the titers of virus shed. This study demonstrates the pathological consequences of the infection of chickens with the 2012 Mexican lineage H7N3 HPAI virus and provides support for effective programs of vaccination against this virus in poultry. PMID:23760232
-
da Fontoura Budaszewski, Renata; Hudacek, Andrew; Sawatsky, Bevan; Krämer, Beate; Yin, Xiangping
2017-01-01
ABSTRACT The development of multivalent vaccines is an attractive methodology for the simultaneous prevention of several infectious diseases in vulnerable populations. Both canine distemper virus (CDV) and rabies virus (RABV) cause lethal disease in wild and domestic carnivores. While RABV vaccines are inactivated, the live-attenuated CDV vaccines retain residual virulence for highly susceptible wildlife species. In this study, we developed recombinant bivalent vaccine candidates based on recombinant vaccine strain rabies virus particles, which concurrently display the protective CDV and RABV glycoprotein antigens. The recombinant viruses replicated to near-wild-type titers, and the heterologous glycoproteins were efficiently expressed and incorporated in the viral particles. Immunization of ferrets with beta-propiolactone-inactivated recombinant virus particles elicited protective RABV antibody titers, and animals immunized with a combination of CDV attachment protein- and fusion protein-expressing recombinant viruses were protected from lethal CDV challenge. However, animals that were immunized with only a RABV expressing the attachment protein of CDV vaccine strain Onderstepoort succumbed to infection with a more recent wild-type strain, indicating that immune responses to the more conserved fusion protein contribute to protection against heterologous CDV strains. IMPORTANCE Rabies virus and canine distemper virus (CDV) cause high mortality rates and death in many carnivores. While rabies vaccines are inactivated and thus have an excellent safety profile and high stability, live-attenuated CDV vaccines can retain residual virulence in highly susceptible species. Here we generated recombinant inactivated rabies viruses that carry one of the CDV glycoproteins on their surface. Ferrets immunized twice with a mix of recombinant rabies viruses carrying the CDV fusion and attachment glycoproteins were protected from lethal CDV challenge, whereas all animals that received recombinant rabies viruses carrying only the CDV attachment protein according to the same immunization scheme died. Irrespective of the CDV antigens used, all animals developed protective titers against rabies virus, illustrating that a bivalent rabies virus-based vaccine against CDV induces protective immune responses against both pathogens. PMID:28148801
-
WDR5 Facilitates Human Cytomegalovirus Replication by Promoting Capsid Nuclear Egress.
Yang, Bo; Liu, Xi-Juan; Yao, Yongxuan; Jiang, Xuan; Wang, Xian-Zhang; Yang, Hong; Sun, Jin-Yan; Miao, Yun; Wang, Wei; Huang, Zhen-Li; Wang, Yanyi; Tang, Qiyi; Rayner, Simon; Britt, William J; McVoy, Michael A; Luo, Min-Hua; Zhao, Fei
2018-05-01
WD repeat-containing protein 5 (WDR5) is essential for assembling the VISA-associated complex to induce a type I interferon antiviral response to Sendai virus infection. However, the roles of WDR5 in DNA virus infections are not well described. Here, we report that human cytomegalovirus exploits WDR5 to facilitate capsid nuclear egress. Overexpression of WDR5 in fibroblasts slightly enhanced the infectious virus yield. However, WDR5 knockdown dramatically reduced infectious virus titers with only a small decrease in viral genome replication or gene expression. Further investigation of late steps of viral replication found that WDR5 knockdown significantly impaired formation of the viral nuclear egress complex and induced substantially fewer infoldings of the inner nuclear membrane. In addition, fewer capsids were associated with these infoldings, and there were fewer capsids in the cytoplasm. Restoration of WDR5 partially reversed these effects. These results suggest that WDR5 knockdown impairs the nuclear egress of capsids, which in turn decreases virus titers. These findings reveal an important role for a host factor whose function(s) is usurped by a viral pathogen to promote efficient replication. Thus, WDR5 represents an interesting regulatory mechanism and a potential antiviral target. IMPORTANCE Human cytomegalovirus (HCMV) has a large (∼235-kb) genome with over 170 open reading frames and exploits numerous cellular factors to facilitate its replication. HCMV infection increases protein levels of WD repeat-containing protein 5 (WDR5) during infection, overexpression of WDR5 enhances viral replication, and knockdown of WDR5 dramatically attenuates viral replication. Our results indicate that WDR5 promotes the nuclear egress of viral capsids, the depletion of WDR5 resulting in a significant decrease in production of infectious virions. This is the first report that WDR5 favors HCMV, a DNA virus, replication and highlights a novel target for antiviral therapy. Copyright © 2018 American Society for Microbiology.
-
2010-01-01
Background The BALB/c mouse is commonly used to study RSV infection and disease. However, despite the many advantages of this well-characterised model, the inoculum is large, viral replication is restricted and only a very small amount of virus can be recovered from infected animals. A key question in this model is the fate of the administered virus. Is replication really being measured or is the model measuring the survival of the virus over time? To answer these questions we developed a highly sensitive strand-specific quantitative PCR (QPCR) able to accurately quantify the amount of RSV replication in the BALB/c mouse lung, allowing characterisation of RSV negative and positive strand RNA dynamics. Results In the mouse lung, no increase in RSV genome was seen above the background of the original inoculum whilst only a limited transient increase (< 1 log) in positive strand, replicative intermediate (RI) RNA occurred. This RNA did however persist at detectable levels for 59 days post infection. As expected, ribavirin therapy reduced levels of infectious virus and RI RNA in the mouse lung. However, whilst Palivizumab therapy was also able to reduce levels of infectious virus, it failed to prevent production of intracellular RI RNA. A comparison of RSV RNA kinetics in human (A549) and mouse (KLN205) cell lines demonstrated that RSV replication was also severely delayed and impaired in vitro in the mouse cells. Conclusions This is the first time that such a sensitive strand-specific QPCR technique has been to the RSV mouse system. We have accurately quantified the restricted and abortive nature of RSV replication in the mouse. Further in vitro studies in human and mouse cells suggest this restricted replication is due at least in part to species-specific host cell-viral interactions. PMID:20860795
-
The emerging role of nuclear viral DNA sensors.
Diner, Benjamin A; Lum, Krystal K; Cristea, Ileana M
2015-10-30
Detecting pathogenic DNA by intracellular receptors termed "sensors" is critical toward galvanizing host immune responses and eliminating microbial infections. Emerging evidence has challenged the dogma that sensing of viral DNA occurs exclusively in sub-cellular compartments normally devoid of cellular DNA. The interferon-inducible protein IFI16 was shown to bind nuclear viral DNA and initiate immune signaling, culminating in antiviral cytokine secretion. Here, we review the newly characterized nucleus-originating immune signaling pathways, their links to other crucial host defenses, and unique mechanisms by which viruses suppress their functions. We frame these findings in the context of human pathologies associated with nuclear replicating DNA viruses. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.
-
A chimeric measles virus with a lentiviral envelope replicates exclusively in CD4+/CCR5+ cells
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mourez, Thomas; APHP, GH Saint-Louis-Lariboisiere, Laboratoire de Bacteriologie-Virologie, F-75010 Paris; Universite Paris 7 Denis Diderot, F-75010 Paris
2011-10-25
We generated a replicating chimeric measles virus in which the hemagglutinin and fusion surface glycoproteins were replaced with the gp160 envelope glycoprotein of simian immunodeficiency virus (SIVmac239). Based on a previously cloned live-attenuated Schwarz vaccine strain of measles virus (MV), this chimera was rescued at high titers using reverse genetics in CD4+ target cells. Cytopathic effect consisted in the presence of large cell aggregates evolving to form syncytia, as observed during SIV infection. The morphology of the chimeric virus was identical to that of the parent MV particles. The presence of SIV gp160 as the only envelope protein on chimericmore » particles surface altered the cell tropism of the new virus from CD46+ to CD4+ cells. Used as an HIV candidate vaccine, this MV/SIVenv chimeric virus would mimic transient HIV-like infection, benefiting both from HIV-like tropism and the capacity of MV to replicate in dendritic cells, macrophages and lymphocytes.« less
-
Xu, Kai; Nagy, Peter D
2017-04-01
Membranous structures derived from various organelles are important for replication of plus-stranded RNA viruses. Although the important roles of co-opted host proteins in RNA virus replication have been appreciated for a decade, the equally important functions of cellular lipids in virus replication have been gaining full attention only recently. Previous work with Tomato bushy stunt tombusvirus (TBSV) in model host yeast has revealed essential roles for phosphatidylethanolamine and sterols in viral replication. To further our understanding of the role of sterols in tombusvirus replication, in this work we showed that the TBSV p33 and p92 replication proteins could bind to sterols in vitro The sterol binding by p33 is supported by cholesterol recognition/interaction amino acid consensus (CRAC) and CARC-like sequences within the two transmembrane domains of p33. Mutagenesis of the critical Y amino acids within the CRAC and CARC sequences blocked TBSV replication in yeast and plant cells. We also showed the enrichment of sterols in the detergent-resistant membrane (DRM) fractions obtained from yeast and plant cells replicating TBSV. The DRMs could support viral RNA synthesis on both the endogenous and exogenous templates. A lipidomic approach showed the lack of enhancement of sterol levels in yeast and plant cells replicating TBSV. The data support the notion that the TBSV replication proteins are associated with sterol-rich detergent-resistant membranes in yeast and plant cells. Together, the results obtained in this study and the previously published results support the local enrichment of sterols around the viral replication proteins that is critical for TBSV replication. IMPORTANCE One intriguing aspect of viral infections is their dependence on efficient subcellular assembly platforms serving replication, virion assembly, or virus egress via budding out of infected cells. These assembly platforms might involve sterol-rich membrane microdomains, which are heterogeneous and highly dynamic nanoscale structures usurped by various viruses. Here, we demonstrate that TBSV p33 and p92 replication proteins can bind to sterol in vitro Mutagenesis analysis of p33 within the CRAC and CARC sequences involved in sterol binding shows the important connection between the abilities of p33 to bind to sterol and to support TBSV replication in yeast and plant cells. Together, the results further strengthen the model that cellular sterols are essential as proviral lipids during viral replication. Copyright © 2017 American Society for Microbiology.
-
Wyld, Sara; Valarcher, Jean-Francois; Guzman, Efrain; Thom, Michelle; Widdison, Stephanie; Buchholz, Ursula J.
2014-01-01
Bovine respiratory syncytial virus (BRSV) causes inflammation and obstruction of the small airways, leading to severe respiratory disease in young calves. The virus is closely related to human (H)RSV, a major cause of bronchiolitis and pneumonia in young children. The ability to manipulate the genome of RSV has provided opportunities for the development of stable, live attenuated RSV vaccines. The role of the SH protein in the pathogenesis of BRSV was evaluated in vitro and in vivo using a recombinant (r)BRSV in which the SH gene had been deleted. Infection of bovine epithelial cells and monocytes with rBRSVΔSH, in vitro, resulted in an increase in apoptosis, and higher levels of TNF-α and IL-1β compared with cells infected with parental, wild-type (WT) rBRSV. Although replication of rBRSVΔSH and WT rBRSV, in vitro, were similar, the replication of rBRSVΔSH was moderately reduced in the lower, but not the upper, respiratory tract of experimentally infected calves. Despite the greater ability of rBRSVΔSH to induce pro-inflammatory cytokines, in vitro, the pulmonary inflammatory response in rBRSVΔSH-infected calves was significantly reduced compared with that in calves inoculated with WT rBRSV, 6 days previously. Virus lacking SH appeared to be as immunogenic and effective in inducing resistance to virulent virus challenge, 6 months later, as the parental rBRSV. These findings suggest that rBRSVΔSH may be an ideal live attenuated virus vaccine candidate, combining safety with a high level of immunogenicity. PMID:24700100
-
Postdoctoral Fellow | Center for Cancer Research
A postdoctoral position is available in the Viral Recombination Section (VRS), HIV Dynamics and Replication Program, CCR. The VRS studies retroviral replication using human immunodeficiency viruses and other retroviruses, with a particular emphasis on the mechanisms of viral RNA biology, specific RNA packaging, virus assembly, and HIV replication. Molecular tools and advanced imaging approaches are used to dissect various aspects of viral replication mechanisms. A more complete description of the projects can be found at http://home.ncifcrf.gov/hivdrp/Hu_res.html.
-
Santhakumar, Diwakar; Rohaim, Mohammed Abdel Mohsen Shahaat; Hussein, Hussein A; Hawes, Pippa; Ferreira, Helena Lage; Behboudi, Shahriar; Iqbal, Munir; Nair, Venugopal; Arns, Clarice W; Munir, Muhammad
2018-05-01
The intracellular actions of interferon (IFN)-regulated proteins, including IFN-induced proteins with tetratricopeptide repeats (IFITs), attribute a major component of the protective antiviral host defense. Here we applied genomics approaches to annotate the chicken IFIT locus and currently identified a single IFIT (chIFIT5) gene. The profound transcriptional level of this effector of innate immunity was mapped within its unique cis-acting elements. This highly virus- and IFN-responsive chIFIT5 protein interacted with negative sense viral RNA structures that carried a triphosphate group on its 5' terminus (ppp-RNA). This interaction reduced the replication of RNA viruses in lentivirus-mediated IFIT5-stable chicken fibroblasts whereas CRISPR/Cas9-edited chIFIT5 gene knockout fibroblasts supported the replication of RNA viruses. Finally, we generated mosaic transgenic chicken embryos stably expressing chIFIT5 protein or knocked-down for endogenous chIFIT5 gene. Replication kinetics of RNA viruses in these transgenic chicken embryos demonstrated the antiviral potential of chIFIT5 in ovo. Taken together, these findings propose that IFIT5 specifically antagonize RNA viruses by sequestering viral nucleic acids in chickens, which are unique in innate immune sensing and responses to viruses of both poultry and human health significance.
-
Identifying Early Target Cells of Nipah Virus Infection in Syrian Hamsters
Baseler, Laura; Scott, Dana P.; Saturday, Greg; Horne, Eva; Rosenke, Rebecca; Thomas, Tina; Meade-White, Kimberly; Haddock, Elaine; Feldmann, Heinz
2016-01-01
Background Nipah virus causes respiratory and neurologic disease with case fatality rates up to 100% in individual outbreaks. End stage lesions have been described in the respiratory and nervous systems, vasculature and often lymphoid organs in fatal human cases; however, the initial target organs of Nipah virus infection have not been identified. Here, we detected the initial target tissues and cells of Nipah virus and tracked virus dissemination during the early phase of infection in Syrian hamsters inoculated with a Nipah virus isolate from Malaysia (NiV-M) or Bangladesh (NiV-B). Methodology/Principal Findings Syrian hamsters were euthanized between 4 and 48 hours post intranasal inoculation and tissues were collected and analyzed for the presence of viral RNA, viral antigen and infectious virus. Virus replication was first detected at 8 hours post inoculation (hpi). Nipah virus initially targeted type I pneumocytes, bronchiolar respiratory epithelium and alveolar macrophages in the lung and respiratory and olfactory epithelium lining the nasal turbinates. By 16 hpi, virus disseminated to epithelial cells lining the larynx and trachea. Although the pattern of viral dissemination was similar for both virus isolates, the rate of spread was slower for NiV-B. Infectious virus was not detected in the nervous system or blood and widespread vascular infection and lesions within lymphoid organs were not observed, even at 48 hpi. Conclusions/Significance Nipah virus initially targets the respiratory system. Virus replication in the brain and infection of blood vessels in non-respiratory tissues does not occur during the early phase of infection. However, virus replicates early in olfactory epithelium and may serve as the first step towards nervous system dissemination, suggesting that development of vaccines that block virus dissemination or treatments that can access the brain and spinal cord and directly inhibit virus replication may be necessary for preventing central nervous system pathology. PMID:27812087
-
Le Mercier, Philippe; Jacob, Yves; Tanner, Kyle; Tordo, Noël
2002-01-01
By comparing three expression vectors for the rabies virus (Rv) minigenome, we show that the characteristic of the Rv RNA is important for efficient rescue despite its not being crucial for replication. Moreover, we show that the coexpression of the viral proteins from helper Rv and Mokola virus could rescue the Rv minigenome while Rv-related European bat lyssavirus 1 could not, suggesting that the signals controlling transcription and replication are conserved in the distantly related Rv and Mokola virus. PMID:11799201
-
HMGB1 Protein Binds to Influenza Virus Nucleoprotein and Promotes Viral Replication
Moisy, Dorothée; Avilov, Sergiy V.; Jacob, Yves; Laoide, Brid M.; Ge, Xingyi; Baudin, Florence; Jestin, Jean-Luc
2012-01-01
Influenza virus has evolved replication strategies that hijack host cell pathways. To uncover interactions between viral macromolecules and host proteins, we applied a phage display strategy. A library of human cDNA expression products displayed on filamentous phages was submitted to affinity selection for influenza viral ribonucleoproteins (vRNPs). High-mobility-group box (HMGB) proteins were found to bind to the nucleoprotein (NP) component of vRNPs. HMGB1 and HMGB2 bind directly to the purified NP in the absence of viral RNA, and the HMG box A domain is sufficient to bind the NP. We show that HMGB1 associates with the viral NP in the nuclei of infected cells, promotes viral growth, and enhances the activity of the viral polymerase. The presence of a functional HMGB1 DNA-binding site is required to enhance influenza virus replication. Glycyrrhizin, which reduces HMGB1 binding to DNA, inhibits influenza virus polymerase activity. Our data show that the HMGB1 protein can play a significant role in intranuclear replication of influenza viruses, thus extending previous findings on the bornavirus and on a number of DNA viruses. PMID:22696656
-
Macrophages in Progressive Human Immunodeficiency Virus/Simian Immunodeficiency Virus Infections
DiNapoli, Sarah R.; Hirsch, Vanessa M.
2016-01-01
The cells that are targeted by primate lentiviruses (HIV and simian immunodeficiency virus [SIV]) are of intense interest given the renewed effort to identify potential cures for HIV. These viruses have been reported to infect multiple cell lineages of hematopoietic origin, including all phenotypic and functional CD4 T cell subsets. The two most commonly reported cell types that become infected in vivo are memory CD4 T cells and tissue-resident macrophages. Though viral infection of CD4 T cells is routinely detected in both HIV-infected humans and SIV-infected Asian macaques, significant viral infection of macrophages is only routinely observed in animal models wherein CD4 T cells are almost entirely depleted. Here we review the roles of macrophages in lentiviral disease progression, the evidence that macrophages support viral replication in vivo, the animal models where macrophage-mediated replication of SIV is thought to occur, how the virus can interact with macrophages in vivo, pathologies thought to be attributed to viral replication within macrophages, how viral replication in macrophages might contribute to the asymptomatic phase of HIV/SIV infection, and whether macrophages represent a long-lived reservoir for the virus. PMID:27307568
-
Small molecules targeting viral RNA.
Hermann, Thomas
2016-11-01
Highly conserved noncoding RNA (ncRNA) elements in viral genomes and transcripts offer new opportunities to expand the repertoire of drug targets for the development of antiinfective therapy. Ligands binding to ncRNA architectures are able to affect interactions, structural stability or conformational changes and thereby block processes essential for viral replication. Proof of concept for targeting functional RNA by small molecule inhibitors has been demonstrated for multiple viruses with RNA genomes. Strategies to identify antiviral compounds as inhibitors of ncRNA are increasingly emphasizing consideration of drug-like properties of candidate molecules emerging from screening and ligand design. Recent efforts of antiviral lead discovery for RNA targets have provided drug-like small molecules that inhibit viral replication and include inhibitors of human immunodeficiency virus (HIV), hepatitis C virus (HCV), severe respiratory syndrome coronavirus (SARS CoV), and influenza A virus. While target selectivity remains a challenge for the discovery of useful RNA-binding compounds, a better understanding is emerging of properties that define RNA targets amenable for inhibition by small molecule ligands. Insight from successful approaches of targeting viral ncRNA in HIV, HCV, SARS CoV, and influenza A will provide a basis for the future exploration of RNA targets for therapeutic intervention in other viral pathogens which create urgent, unmet medical needs. Viruses for which targeting ncRNA components in the genome or transcripts may be promising include insect-borne flaviviruses (Dengue, Zika, and West Nile) and filoviruses (Ebola and Marburg). WIREs RNA 2016, 7:726-743. doi: 10.1002/wrna.1373 For further resources related to this article, please visit the WIREs website. © 2016 Wiley Periodicals, Inc.
-
Mao, Yaping; Wang, Jigui; Hou, Qiang; Xi, Ji; Zhang, Xiaomei; Bian, Dawei; Yu, Yongle; Wang, Xi; Liu, Weiquan
2016-06-01
A virus isolated from mink showing clinical signs of enteritis was identified as a high virulent mink enteritis parvovirus (MEV) based on its biological characteristics in vivo and in vitro. Mink, challenged with this strain named MEV-LHV, exhibited severe pathological lesions as compared to those challenged with attenuated strain MEV-L. MEV-LHV also showed higher infection and replication efficiencies in vitro than MEV-L. Sequence of the complete genome of MEV-LHV was determined and analyzed in comparison with those in GenBank, which revealed that MEV-LHV shared high homology with virulent strain MEV SD12/01, whereas MEV-L was closely related to Abashiri and vaccine strain MEVB, and belonged to a different branch of the phylogenetic tree. The genomes of the two strains differed by insertions and deletions in their palindromic termini and specific unique mutations (especially VP2 300) in coding sequences which may be involved in viral replication and pathogenicity. The results of this study provide a better understanding of the biological and genomic characteristics of MEV and identify certain regions and sites that may be involved in viral replication and pathogenicity.
-
Hepatitis C Virus Replication Depends on Endosomal Cholesterol Homeostasis.
Stoeck, Ina Karen; Lee, Ji-Young; Tabata, Keisuke; Romero-Brey, Inés; Paul, David; Schult, Philipp; Lohmann, Volker; Kaderali, Lars; Bartenschlager, Ralf
2018-01-01
Similar to other positive-strand RNA viruses, hepatitis C virus (HCV) causes massive rearrangements of intracellular membranes, resulting in a membranous web (MW) composed of predominantly double-membrane vesicles (DMVs), the presumed sites of RNA replication. DMVs are enriched for cholesterol, but mechanistic details on the source and recruitment of cholesterol to the viral replication organelle are only partially known. Here we focused on selected lipid transfer proteins implicated in direct lipid transfer at various endoplasmic reticulum (ER)-membrane contact sites. RNA interference (RNAi)-mediated knockdown identified several hitherto unknown HCV dependency factors, such as steroidogenic acute regulatory protein-related lipid transfer domain protein 3 (STARD3), oxysterol-binding protein-related protein 1A and -B (OSBPL1A and -B), and Niemann-Pick-type C1 (NPC1), all residing at late endosome and lysosome membranes and required for efficient HCV RNA replication but not for replication of the closely related dengue virus. Focusing on NPC1, we found that knockdown or pharmacological inhibition caused cholesterol entrapment in lysosomal vesicles concomitant with decreased cholesterol abundance at sites containing the viral replicase factor NS5A. In untreated HCV-infected cells, unesterified cholesterol accumulated at the perinuclear region, partially colocalizing with NS5A at DMVs, arguing for NPC1-mediated endosomal cholesterol transport to the viral replication organelle. Consistent with cholesterol being an important structural component of DMVs, reducing NPC1-dependent endosomal cholesterol transport impaired MW integrity. This suggests that HCV usurps lipid transfer proteins, such as NPC1, at ER-late endosome/lysosome membrane contact sites to recruit cholesterol to the viral replication organelle, where it contributes to MW functionality. IMPORTANCE A key feature of the replication of positive-strand RNA viruses is the rearrangement of the host cell endomembrane system to produce a membranous replication organelle (RO). The underlying mechanisms are far from being elucidated fully. In this report, we provide evidence that HCV RNA replication depends on functional lipid transport along the endosomal-lysosomal pathway that is mediated by several lipid transfer proteins, such as the Niemann-Pick type C1 (NPC1) protein. Pharmacological inhibition of NPC1 function reduced viral replication, impaired the transport of cholesterol to the viral replication organelle, and altered organelle morphology. Besides NPC1, our study reports the importance of additional endosomal and lysosomal lipid transfer proteins required for viral replication, thus contributing to our understanding of how HCV manipulates their function in order to generate a membranous replication organelle. These results might have implications for the biogenesis of replication organelles of other positive-strand RNA viruses. Copyright © 2017 American Society for Microbiology.
-
Novella, Isabel S; Ebendick-Corpus, Bonnie E; Zárate, Selene; Miller, Eric L
2007-06-01
Arboviruses (arthropod-borne viruses) represent quintessential generalists, with the ability to infect and perform well in multiple hosts. However, antagonistic pleiotropy imposed a cost during the adaptation to persistent replication of vesicular stomatitis virus in sand fly cells and resulted in strains that initially replicated poorly in hamster cells, even when the virus was allowed to replicate periodically in the latter. Once a debilitated strain started replicating continuously in mammalian cells, fitness increased significantly. Fitness recovery did not entail back mutations or compensatory mutations, but instead, we observed the replacement of persistence-adapted genomes by mammalian cell-adapted strains with a full set of new, unrelated sequence changes. These mammalian cell-adapted genomes were present at low frequencies in the populations with a history of persistence for up to a year and quickly became dominant during mammalian infection, but coexistence was not stable in the long term. Periodic acute replication in mammalian cells likely contributed to extending the survival of minority genomes, but these genomes were also found in strictly persistent populations.
-
Li, Su; Wang, Jinghan; Yang, Qian; Naveed Anwar, Muhammad; Yu, Shaoxiong; Qiu, Hua-Ji
2017-07-05
Classical swine fever (CSF), caused by classical swine fever virus (CSFV), is one of the most devastating epizootic diseases of pigs in many countries. Viruses are small intracellular parasites and thus rely on the cellular factors for replication. Fundamental aspects of CSFV-host interactions have been well described, such as factors contributing to viral attachment, modulation of genomic replication and translation, antagonism of innate immunity, and inhibition of cell apoptosis. However, those host factors that participate in the viral entry, assembly, and release largely remain to be elucidated. In this review, we summarize recent progress in the virus-host interactions involved in the life cycle of CSFV and analyze the potential mechanisms of viral entry, assembly, and release. We conclude with future perspectives and highlight areas that require further understanding.
-
The chaperonin CCTα is required for efficient transcription and replication of rabies virus.
Zhang, Jinyang; Ye, Chengjin; Ruan, Xizhen; Zan, Jie; Xu, Yunbin; Liao, Min; Zhou, Jiyong
2014-10-01
Negri bodies (NBs) are formed in the cytoplasm of rabies virus (RABV)-infected cells and are accompanied by a number of host factors to NBs, in which replication and transcription occur. Here, it was found that chaperonin containing TCP-1 subunit alpha (CCTα) relocalizes to NBs in RABV-infected cells, and that cotransfection of nucleo- and phospho-proteins of RABV is sufficient to recruit CCTα to the NBs' structure. Inhibition of CCTα expression by specific short hairpin RNA knockdown inhibited the replication and transcription of RABV. Therefore, this study showed that the host factor CCTα is associated with RABV infection and is very likely required for efficient virus transcription and replication. © 2014 The Societies and Wiley Publishing Asia Pty Ltd.
-
Inhibition of Human Immunodeficiency Virus Replication by Antisense Oligodeoxynucleotides
NASA Astrophysics Data System (ADS)
Goodchild, John; Agrawal, Sudhir; Civeira, Maria P.; Sarin, Prem S.; Sun, Daisy; Zamecnik, Paul C.
1988-08-01
Twenty different target sites within human immunodeficiency virus (HIV) RNA were selected for studies of inhibition of HIV replication by antisense oligonucleotides. Target sites were selected based on their potential capacity to block recognition functions during viral replication. Antisense oligomers complementary to sites within or near the sequence repeated at the ends of retrovirus RNA (R region) and to certain splice sites were most effective. The effect of antisense oligomer length on inhibiting virus replication was also investigated, and preliminary toxicity studies in mice show that these compounds are toxic only at high levels. The results indicate potential usefulness for these oligomers in the treatment of patients with acquired immunodeficiency syndrome (AIDS) and AIDS-related complex either alone or in combination with other drugs.
-
Zika Virus Attenuation by Codon Pair Deoptimization Induces Sterilizing Immunity in Mouse Models.
Li, Penghui; Ke, Xianliang; Wang, Ting; Tan, Zhongyuan; Luo, Dan; Miao, Yuanjiu; Sun, Jianhong; Zhang, Yuan; Liu, Yan; Hu, Qinxue; Xu, Fuqiang; Wang, Hanzhong; Zheng, Zhenhua
2018-06-20
Zika virus (ZIKV) infection during the large epidemics in the Americas is related to congenital abnormities or fetal demise. To date, there is no vaccine, antiviral drug, or other modality available to prevent or treat Zika virus infection. Here we designed novel live attenuated ZIKV vaccine candidates using a codon pair deoptimization strategy. Three codon pair-deoptimized ZIKVs (Min E, Min NS1, and Min E+NS1) were de novo synthesized, and recovered by reverse genetics, containing large amounts of underrepresented codon pairs in E gene and/or NS1 gene. Amino acid sequence was 100% unchanged. The codon pair-deoptimized variants had decreased replication fitness in Vero cells (Min NS1 ≫ Min E > Min E+NS1), replicated more efficiently in insect cells than in mammalian cells, and demonstrated diminished virulence in a mouse model. In particular, Min E+NS1, the most restrictive variant, induced sterilizing immunity with a robust neutralizing antibody titer, and a single immunization achieved complete protection against lethal challenge and vertical ZIKV transmission during pregnancy. More importantly, due to the numerous synonymous substitutions in the codon pair-deoptimized strains, reversion to wild-type virulence through gradual nucleotide sequence mutations is unlikely. Our results collectively demonstrate that ZIKV can be effectively attenuated by codon pair deoptimization, highlighting the potential of Min E+NS1 as a safe vaccine candidate to prevent ZIKV infections. IMPORTANCE Due to unprecedented epidemics of Zika virus (ZIKV) across the Americas and the unexpected clinical symptoms including Guillain-Barré syndrome, microcephaly and other birth defects in human, there is an urgent need for ZIKV vaccine development. Here, we provided the first attenuated versions of ZIKV with two important genes (E and/or NS1) that were subjected to codon pair deoptimization. Compared to parental ZIKV, the codon pair-deoptimized ZIKVs were mammalian-attenuated, and preferred insect to mammalian Cells. Min E+NS1, the most restrictive variant, induced sterilizing immunity with a robust neutralizing antibody titer, and achieved complete protection against lethal challenge and vertical virus transmission during pregnancy. More importantly, the massive synonymous mutational approach made it impossible to revert to wild-type virulence. Our results have proven the feasibility of codon pair deoptimization as a strategy to develop live-attenuated vaccine candidates against flavivirues like ZIKV, Japanese encephalitis virus and West Nile virus. Copyright © 2018 American Society for Microbiology.
-
Kurath, Gael; Jolley, C J.; Thompson, Tarin M.; Thompson, D.; Whitesel, A.T.; Gutenberger, S.; Winton, James R.
2013-01-01
Pacific Lampreys Entosphenus tridentatus have experienced severe population declines in recent years and efforts to develop captive rearing programs are under consideration. However, there is limited knowledge of their life history, ecology, and potential to harbor or transmit pathogens that may cause infectious disease. As a measure of the possible risks associated with introducing wild lampreys into existing fish culture facilities, larval lampreys (ammocoetes) were tested for susceptibility to infection and mortality caused by experimental exposures to the fish rhabdovirus pathogens: infectious hematopoietic necrosis virus (IHNV) and viral haemorrhagic septicaemia virus (VHSV). Two IHNV isolates, representing the U and M genogroups, and one VHSV isolate from the IVa genotype were each delivered to groups of ammocoetes by immersion at moderate and high viral doses, and by intraperitoneal injection. Ammocoetes were then held in triplicate tanks with no substrate or sediment. During 41 d of observation postchallenge there was low or no mortality in all groups, and no virus was detected in the small number of fish that died. Ammocoetes sampled for incidence of infection at 6 and 12 d after immersion challenges also had no detectable virus, and no virus was detected in surviving fish from any group. A small number of ammocoetes sampled 6 d after the injection challenge had detectable virus, but at levels below the original quantity of virus injected. Overall there was no evidence of infection, replication, or persistence of any of the viruses in any of the treatment groups. Our results suggest that Pacific Lampreys are highly unlikely to serve as hosts that maintain or transmit these viruses.