The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Adolfo Garciasastre - One of the best experts on this subject based on the ideXlab platform.
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Broadly cross reactive nonneutralizing antiBodies against <B>InfluenzaB> B Virus hemagglutinin demonstrate effector function dependent protection against lethal viral challenge in mice
Journal of Virology, 2019Co-Authors: Guha Asthagiri Arunkumar, Andriani Ioannou, Teddy John Wohlbold, Philip Meade, Sadaf Aslam, Fatima Amanat, Juan Ayllon, Adolfo Garciasastre, Florian KrammerAbstract:Protection from <B>InfluenzaB> Virus infection is canonically associated with antiBodies that neutralize the Virus By Blocking the interaction Between the viral hemagglutinin and host cell receptors. However, protection can also Be conferred By other mechanisms, including antiBody-mediated effector functions. Here, we report the characterization of 22 Broadly cross-reactive, nonneutralizing antiBodies specific for <B>InfluenzaB> B Virus hemagglutinin. The majority of these antiBodies recognized <B>InfluenzaB> B Viruses isolated over the period of 73 years and Bind the conserved stalk domain of the hemagglutinin. A proportion of the characterized antiBodies protected mice from Both morBidity and mortality after challenge with a lethal dose of <B>InfluenzaB> B Virus. Activity in an antiBody-dependent cell-mediated cytotoxicity reporter assay correlated strongly with protection, suggesting that Fc-dependent effector function determines protective efficacy. The information regarding mechanism of action and epitope location stemming from our characterization of these antiBodies will inform the design of urgently needed vaccines that could induce Broad protection against <B>InfluenzaB> B Viruses. IMPORTANCE While Broadly protective antiBodies against the <B>InfluenzaB> A Virus hemagglutinin have Been well studied, very limited information is availaBle for antiBodies that Broadly recognize <B>InfluenzaB> B Viruses. Similarly, the development of a universal or Broadly protective <B>InfluenzaB> B Virus vaccine lags Behind the development of such a vaccine for <B>InfluenzaB> A Virus. More information aBout epitope location and mechanism of action of Broadly protective <B>InfluenzaB> B Virus antiBodies is required to inform vaccine development. In addition, protective antiBodies could Be a useful tool to treat or prevent <B>InfluenzaB> B Virus infection in pediatric cohorts or in a therapeutic setting in immunocompromised individuals in conjugation with existing treatment avenues.
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Broadly cross reactive nonneutralizing antiBodies against <B>InfluenzaB> B Virus hemagglutinin demonstrate effector function dependent protection against lethal viral challenge in mice
Journal of Virology, 2019Co-Authors: Guha Asthagiri Arunkumar, Andriani Ioannou, Teddy John Wohlbold, Philip Meade, Sadaf Aslam, Fatima Amanat, Juan Ayllon, Adolfo GarciasastreAbstract:Protection from <B>InfluenzaB> Virus infection is canonically associated with antiBodies that neutralize the Virus By Blocking the interaction Between the viral hemagglutinin and host cell receptors. However, protection can also Be conferred By other mechanisms, including antiBody-mediated effector functions. Here, we report the characterization of 22 Broadly cross-reactive, nonneutralizing antiBodies specific for <B>InfluenzaB> B Virus hemagglutinin. The majority of these antiBodies recognized <B>InfluenzaB> B Viruses isolated over the period of 73 years and Bind the conserved stalk domain of the hemagglutinin. A proportion of the characterized antiBodies protected mice from Both morBidity and mortality after challenge with a lethal dose of <B>InfluenzaB> B Virus. Activity in an antiBody-dependent cell-mediated cytotoxicity reporter assay correlated strongly with protection, suggesting that Fc-dependent effector function determines protective efficacy. The information regarding mechanism of action and epitope location stemming from our characterization of these antiBodies will inform the design of urgently needed vaccines that could induce Broad protection against <B>InfluenzaB> B Viruses. IMPORTANCE While Broadly protective antiBodies against the <B>InfluenzaB> A Virus hemagglutinin have Been well studied, very limited information is availaBle for antiBodies that Broadly recognize <B>InfluenzaB> B Viruses. Similarly, the development of a universal or Broadly protective <B>InfluenzaB> B Virus vaccine lags Behind the development of such a vaccine for <B>InfluenzaB> A Virus. More information aBout epitope location and mechanism of action of Broadly protective <B>InfluenzaB> B Virus antiBodies is required to inform vaccine development. In addition, protective antiBodies could Be a useful tool to treat or prevent <B>InfluenzaB> B Virus infection in pediatric cohorts or in a therapeutic setting in immunocompromised individuals in conjugation with existing treatment avenues.
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mice lacking the isg15 e1 enzyme uBe1l demonstrate increased susceptiBility to Both mouse adapted and non mouse adapted <B>InfluenzaB> B Virus infection
Journal of Virology, 2009Co-Authors: Caroline Lai, Dong-er Zhang, Adolfo Garciasastre, Thorsten Wolff, Jessica J Struckhoff, Jana Schneider, Luis Martinezsobrido, Deborah J LenschowAbstract:ISG15 functions as a critical antiviral molecule against <B>InfluenzaB> Virus, with infection inducing Both the conjugation of ISG15 to target proteins and production of free ISG15. Here, we report that mice lacking the ISG15 E1 enzyme UBE1L fail to form ISG15 conjugates. Both UBE1L−/− and ISG15−/− mice display increased susceptiBility to <B>InfluenzaB> B Virus infection, including non-mouse-adapted strains. Finally, we demonstrate that ISG15 controls <B>InfluenzaB> B Virus infection through its action within radioresistant stromal cells and not Bone marrow-derived cells. Thus, the conjugation of ISG15 to target proteins within stromal cells is critical to its activity against <B>InfluenzaB> Virus.
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<B>InfluenzaB> B Virus ns1 truncated mutants live attenuated vaccine approach
Journal of Virology, 2008Co-Authors: Rong Hai, Juan Ayllon, Adolfo Garciasastre, Luis Martinezsobrido, Kathryn A Fraser, Peter PaleseAbstract:Type B <B>InfluenzaB> Viruses can cause suBstantial morBidity and mortality in the population, and vaccination remains By far the Best means of protection against infections with these Viruses. Here, we report the construction of mutant <B>InfluenzaB> B Viruses for potential use as improved live-Virus vaccine candidates. Employing reverse genetics, we altered the NS1 gene, which encodes a type I interferon (IFN) antagonist. The resulting NS1 mutant Viruses induced IFN and, as a consequence, were found to Be attenuated in vitro and in vivo. The aBsence of pathogenicity of the NS1 mutants in Both BALB/c and C57BL/6 PKR−/− mice was confirmed. We also provide evidence that <B>InfluenzaB> B Virus NS1 mutants induce a self-adjuvanted immune response and confer effective protection against challenge with Both homologous and heterologous B Virus strains in mice.
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the n and c terminal domains of the ns1 protein of <B>InfluenzaB> B Virus can independently inhiBit irf 3 and Beta interferon promoter activation
Journal of Virology, 2004Co-Authors: Nicola R Donelan, Thorsten Wolff, Bianca Dauber, Xiuyan Wang, Christopher F Basler, Adolfo GarciasastreAbstract:The NS1 proteins of <B>InfluenzaB> A and B Viruses (A/NS1 and B/NS1 proteins) have only ∼20% amino acid sequence identity. Nevertheless, these proteins show several functional similarities, such as their aBility to Bind to the same RNA targets and to inhiBit the activation of protein kinase R in vitro. A critical function of the A/NS1 protein is the inhiBition of synthesis of alpha/Beta interferon (IFN-α/β) during viral infection. Recently, it was also found that the B/NS1 protein inhiBits IFN-α/β synthesis in Virus-infected cells. We have now found that the expression of the B/NS1 protein complements the growth of an <B>InfluenzaB> A Virus with A/NS1 deleted. Expression of the full-length B/NS1 protein (281 amino acids), as well as either its N-terminal RNA-Binding domain (amino acids 1 to 93) or C-terminal domain (amino acids 94 to 281), in the aBsence of any other <B>InfluenzaB> B Virus proteins resulted in the inhiBition of IRF-3 nuclear translocation and IFN-β promoter activation. A mutational analysis of the truncated B/NS1(1-93) protein showed that RNA-Binding activity correlated with IFN-β promoter inhiBition. In addition, a recomBinant <B>InfluenzaB> B Virus with NS1 deleted induces higher levels of IRF-3 activation, as determined By its nuclear translocation, and of IFN-α/β synthesis than wild-type <B>InfluenzaB> B Virus. Our results support the hypothesis that the NS1 protein of <B>InfluenzaB> B Virus plays an important role in antagonizing the IRF-3- and IFN-induced antiviral host responses to Virus infection.
Thorsten Wolff - One of the best experts on this subject based on the ideXlab platform.
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mice lacking the isg15 e1 enzyme uBe1l demonstrate increased susceptiBility to Both mouse adapted and non mouse adapted <B>InfluenzaB> B Virus infection
Journal of Virology, 2009Co-Authors: Caroline Lai, Dong-er Zhang, Adolfo Garciasastre, Thorsten Wolff, Jessica J Struckhoff, Jana Schneider, Luis Martinezsobrido, Deborah J LenschowAbstract:ISG15 functions as a critical antiviral molecule against <B>InfluenzaB> Virus, with infection inducing Both the conjugation of ISG15 to target proteins and production of free ISG15. Here, we report that mice lacking the ISG15 E1 enzyme UBE1L fail to form ISG15 conjugates. Both UBE1L−/− and ISG15−/− mice display increased susceptiBility to <B>InfluenzaB> B Virus infection, including non-mouse-adapted strains. Finally, we demonstrate that ISG15 controls <B>InfluenzaB> B Virus infection through its action within radioresistant stromal cells and not Bone marrow-derived cells. Thus, the conjugation of ISG15 to target proteins within stromal cells is critical to its activity against <B>InfluenzaB> Virus.
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activation of phosphatidylinositol 3 kinase signaling By the nonstructural ns1 protein is not conserved among type a and B <B>InfluenzaB> Viruses
Journal of Virology, 2007Co-Authors: Christina Ehrhardt, Thorsten Wolff, Stephan LudwigAbstract:Recently it has Been shown By several laBoratories that the <B>InfluenzaB> A Virus nonstructural protein 1 (A/NS1) Binds and activates phosphatidylinositol 3-kinase (PI3K). This function of the protein is likely to prevent premature apoptosis induction during viral propagation. Here we show that the B/NS1 protein completely lacks the capacity to induce PI3K signaling. Thus, PI3K activation is another unique function of A/NS1 that is different from the action of its <B>InfluenzaB> B Virus counterpart.
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douBle stranded rna Binding of <B>InfluenzaB> B Virus nonstructural ns1 protein inhiBits protein kinase r But is not essential to antagonize production of alpha Beta interferon
Journal of Virology, 2006Co-Authors: Bianca Dauber, Jana Schneider, Thorsten WolffAbstract:Expression of alpha/Beta interferon (IFN-α/β) in Virus-infected verteBrate cells is a key event in the estaBlishment of a sustained antiviral response, which is triggered By douBle-stranded RNA (dsRNA) produced during viral replication. These antiviral cytokines initiate the expression of cellular proteins with activities that limit the replication and spread of the invading Viruses. Within this response, the dsRNA-dependent protein kinase R (PKR) that is expressed at constitutive levels and upregulated By IFN-α/β acts as an important antiviral effector that can Block the cellular translational machinery. We previously demonstrated that efficient replication of <B>InfluenzaB> B Virus depends on the viral dsRNA-Binding NS1 protein that inhiBits the transcriptional activation of IFN-α/β genes. Here we tested the postulate that the viral NS1 protein counteracts antiviral responses through sequestering intracellular dsRNA By analyzing a collection of recomBinant <B>InfluenzaB> B Viruses. As expected, Viruses expressing dsRNA-Binding-defective NS1 proteins were strongly attenuated for replication in IFN-competent hosts. Interestingly, these Virus mutants failed to prevent activation of PKR But could effectively limit IFN induction. Conversely, a mutant Virus expressing the N-terminal dsRNA-Binding domain of NS1 prevented PKR activation, But not IFN induction, suggesting an important role for the NS1 C-terminal part in silencing the activation route of IFN-α/β genes. Thus, our findings indicate an unexpected mechanistic dichotomy of the <B>InfluenzaB> B Virus NS1 protein in the suppression of antiviral responses, which involves at least one activity that is largely separaBle from dsRNA Binding.
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the n and c terminal domains of the ns1 protein of <B>InfluenzaB> B Virus can independently inhiBit irf 3 and Beta interferon promoter activation
Journal of Virology, 2004Co-Authors: Nicola R Donelan, Thorsten Wolff, Bianca Dauber, Xiuyan Wang, Christopher F Basler, Adolfo GarciasastreAbstract:The NS1 proteins of <B>InfluenzaB> A and B Viruses (A/NS1 and B/NS1 proteins) have only ∼20% amino acid sequence identity. Nevertheless, these proteins show several functional similarities, such as their aBility to Bind to the same RNA targets and to inhiBit the activation of protein kinase R in vitro. A critical function of the A/NS1 protein is the inhiBition of synthesis of alpha/Beta interferon (IFN-α/β) during viral infection. Recently, it was also found that the B/NS1 protein inhiBits IFN-α/β synthesis in Virus-infected cells. We have now found that the expression of the B/NS1 protein complements the growth of an <B>InfluenzaB> A Virus with A/NS1 deleted. Expression of the full-length B/NS1 protein (281 amino acids), as well as either its N-terminal RNA-Binding domain (amino acids 1 to 93) or C-terminal domain (amino acids 94 to 281), in the aBsence of any other <B>InfluenzaB> B Virus proteins resulted in the inhiBition of IRF-3 nuclear translocation and IFN-β promoter activation. A mutational analysis of the truncated B/NS1(1-93) protein showed that RNA-Binding activity correlated with IFN-β promoter inhiBition. In addition, a recomBinant <B>InfluenzaB> B Virus with NS1 deleted induces higher levels of IRF-3 activation, as determined By its nuclear translocation, and of IFN-α/β synthesis than wild-type <B>InfluenzaB> B Virus. Our results support the hypothesis that the NS1 protein of <B>InfluenzaB> B Virus plays an important role in antagonizing the IRF-3- and IFN-induced antiviral host responses to Virus infection.
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the <B>InfluenzaB> B Virus nonstructural ns1 protein is essential for efficient viral growth and antagonizes Beta interferon induction
Journal of Virology, 2004Co-Authors: Bianca Dauber, Gudrun Heins, Thorsten WolffAbstract:We analyzed the functions of the <B>InfluenzaB> B Virus nonstructural NS1-B protein, Both By utilizing a constructed mutant Virus (ΔNS1-B) lacking the NS1 gene and By testing the activities of the protein when expressed in cells. The mutant Virus replicated to intermediate levels in 6-day-old emBryonated chicken eggs that contain an immature interferon (IFN) system, whereas older eggs did not support viral propagation to a significant extent. The ΔNS1-B Virus was a suBstantially stronger inducer of Beta IFN (IFN-β) transcripts in human lung epithelial cells than the wild type, and furthermore, transiently expressed NS1-B protein efficiently inhiBited Virus-dependent activation of the IFN-β promoter. Interestingly, replication of the ΔNS1-B knockout Virus was attenuated By more than 4 orders of magnitude in tissue culture cells containing or lacking functional IFN-α/β genes. These findings show that the NS1-B protein functions as a viral IFN antagonist and indicate a further requirement of this protein for efficient viral replication that is unrelated to Blocking IFN effects.
Robert M. Krug - One of the best experts on this subject based on the ideXlab platform.
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<B>InfluenzaB> B Virus non structural protein 1 counteracts isg15 antiviral activity By sequestering isgylated viral proteins
Nature Communications, 2016Co-Authors: Chen Zhao, Haripriya Sridharan, Shanshan Wang, Ran Chen, Darren P Baker, Robert M. KrugAbstract:The uBiquitin-like protein ISG15 and its conjugation to proteins (ISGylation) are strongly induced By type I interferon. <B>InfluenzaB> B Virus encodes non-structural protein 1 (NS1B) that Binds human ISG15 and provides an appropriate model for determining how ISGylation affects Virus replication in human cells. Here using a recomBinant Virus encoding a NS1B protein defective in ISG15 Binding, we show that NS1B counteracts ISGylation-mediated antiviral activity By Binding and sequestering ISGylated viral proteins, primarily ISGylated viral nucleoprotein (NP), in infected cells. ISGylated NP that is not sequestered By mutant NS1B acts as a dominant-negative inhiBitor of oligomerization of the more aBundant unconjugated NP. Consequently formation of viral riBonucleoproteins that catalyse viral RNA synthesis is inhiBited, causing decreased viral protein synthesis and Virus replication. We verify that ISGylated NP is largely responsiBle for inhiBition of viral RNA synthesis By generating recomBinant Viruses that lack known ISGylation sites in NP.
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species specificity of the ns1 protein of <B>InfluenzaB> B Virus ns1 Binds only human and non human primate uBiquitin like isg15 proteins
Journal of Biological Chemistry, 2010Co-Authors: Haripriya Sridharan, Chen Zhao, Robert M. KrugAbstract:<B>InfluenzaB> B Viruses, which cause a highly contagious respiratory disease every year, are restricted to humans, But the Basis for this restriction had not Been determined. Here we provide one explanation for this restriction: the species specificity exhiBited By the NS1 protein of <B>InfluenzaB> B Virus (NS1B protein). This viral protein comBats a major host antiviral response By Binding the interferon-α/β-induced, uBiquitin-like ISG15 protein and inhiBiting its conjugation to an array of proteins. We demonstrate that the NS1B protein exhiBits species-specific Binding; it Binds human and non-human primate ISG15 But not mouse or canine ISG15. In Both transfection assays and Virus-infected cells, the NS1B protein Binds and relocalizes only human and non-human primate ISG15 from the cytoplasm to nuclear speckles. Human and non-human primate ISG15 proteins consist of two uBiquitin-like domains separated By a short hinge linker of five amino acids. RemarkaBly, this short hinge plays a large role in the species-specific Binding By the NS1B protein. The hinge of human and non-human primate ISG15, which has a sequence that differs from that of other mammalian ISG15 proteins, including mouse and canine ISG15, is aBsolutely required for Binding the NS1B protein. Consequently, the ISG15 proteins of humans and non-human primates are the only mammalian ISG15 proteins that would Bind NS1B.
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interferon induced isg15 conjugation inhiBits <B>InfluenzaB> a Virus gene expression and replication in human cells
Journal of Virology, 2009Co-Authors: Tien Ying Hsiang, Chen Zhao, Robert M. KrugAbstract:Virus infection activates the synthesis of type I interferons (IFN-α and IFN-β), which induce the synthesis of a large array of proteins, many of which play crucial roles in the antiviral response (1). One of the most strongly induced proteins is ISG15, a 15-kDa uBiquitin-like protein that Becomes conjugated to many cellular proteins (6, 8, 9, 12, 18, 22, 26, 30). Three of the human enzymes that catalyze this conjugation, the UBE1L E1 enzyme, the UBcH8 E2 enzyme, and the Herc5 E3 enzyme, are also induced By IFN-β (4, 10, 26, 27, 29). Although it had Been reported that UBcH8 functions in Both ISG15 and uBiquitin conjugation (3, 10, 13, 25, 28, 29), a recent study demonstrated that UBcH8 is unlikely to function in uBiquitin conjugation in vivo for two reasons: Km measurements revealed that the E1 uBiquitin-activating enzyme, unlike UBE1L, exhiBits very low affinity for UBcH8, and UBcH8 is poorly, if not at all, expressed in the aBsence of IFN treatment, indicating that UBcH8 functions only during the IFN response (5). A large numBer of human proteins that are targets for ISG15 conjugation have Been identified (22, 26, 30). Most of these targets are constitutively expressed proteins that function in diverse cellular pathways, But several of the targets are IFN-α/-β-induced antiviral proteins. Because the NS1 protein of <B>InfluenzaB> B Virus (NS1B) was shown to Bind ISG15 and inhiBit its conjugation to target proteins, it was proposed that ISG15 and/or its conjugation is inhiBitory to the replication of <B>InfluenzaB> B Virus (27). SuBsequently, experiments using ISG15 knockout (ISG15−/−) mice estaBlished that ISG15 and/or its conjugation inhiBits the replication of not only <B>InfluenzaB> B Virus But also <B>InfluenzaB> A Virus (16). For example, at one of the inoculum levels employed for <B>InfluenzaB> A Virus, 52% of the ISG15−/− mice died, whereas a significantly smaller percentage, 23%, of the ISG15+/+ mice died. However, the effect of ISG15 and/or its conjugation on <B>InfluenzaB> A Virus replication was not detected in mouse emBryo fiBroBlasts (MEFs) in tissue culture. MEFs supported only very limited replication of <B>InfluenzaB> A Virus, and there was no significant difference in Virus replication Between ISG15+/+ and ISG15−/− MEFs (16). These investigators postulated that <B>InfluenzaB> A Virus replication was proBaBly selectively spared in other cell types of the ISG15−/− mouse. A suBsequent study showed that ISG15 conjugation exerts its antiviral action against <B>InfluenzaB> B Virus (and presumaBly against <B>InfluenzaB> A Virus) in radioresistant stromal cells of the mouse (14). However, an antiviral effect of ISG15 conjugation against <B>InfluenzaB> A Virus has not yet Been demonstrated in mouse cells in tissue culture. In the present study we focus on human tissue culture cells and on the effect of ISG15 and/or its conjugation on the replication of <B>InfluenzaB> A Virus in such cells. We show that IFN-induced antiviral activity against <B>InfluenzaB> A Virus in human cells is significantly alleviated By inhiBiting ISG15 conjugation using small interfering RNAs (siRNAs) against ISG15-conjugating enzymes. Our results show that Both the synthesis of viral proteins and the early rate of Virus replication are inhiBited By ISG15 conjugation. In contrast, we show that in MEFs ISG15 conjugation not only does not affect <B>InfluenzaB> A Virus replication But also does not contriBute to IFN-induced antiviral activity against <B>InfluenzaB> A Virus gene expression.
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<B>InfluenzaB> B Virus ns1 protein inhiBits conjugation of the interferon ifn induced uBiquitin like isg15 protein
The EMBO Journal, 2001Co-Authors: Weiming Yuan, Robert M. KrugAbstract:Of the several hundred proteins induced By interferon (IFN) α/β, the uBiquitin-like ISG15 protein is one of the most predominant. We demonstrate the novel way in which the function of the ISG15 protein is inhiBited By <B>InfluenzaB> B Virus, which strongly induces the ISG15 protein: a specific region of the <B>InfluenzaB> B Virus NS1 protein, which includes part of its effector domain, Blocks the covalent linkage of ISG15 to its target proteins Both in vitro and in infected cells. We identify UBE1L as the E1 enzyme that catalyzes the first activation step in the conjugation of ISG15, and show that the NS1B protein inhiBits this activation step in vitro. <B>InfluenzaB> A Virus employs a different strategy: its NS1 protein does not Bind the ISG15 protein, But little or no ISG15 protein is produced during infection. We discuss the likely Basis for these different strategies.
Florian Krammer - One of the best experts on this subject based on the ideXlab platform.
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characterization of novel cross reactive <B>InfluenzaB> B Virus hemagglutinin head specific antiBodies that lack hemagglutination inhiBition activity
Journal of Virology, 2020Co-Authors: Ericka Kirkpatrick, Meagan Mcmahon, Shirin Strohmeier, Carole Henry, Kaijun Jiang, Harm Van Bakel, Patrick C Wilson, Florian KrammerAbstract:Humoral immune responses to <B>InfluenzaB> Virus vaccines in elderly individuals are poorly adapted toward new antigenically drifted <B>InfluenzaB> Virus strains. Instead, older individuals respond in an original antigenic sin fashion and produce much more cross-reactive But less potent antiBodies. Here, we investigated four <B>InfluenzaB> B Virus hemagglutinin (HA) head specific, hemagglutination inhiBition-inactive monoclonal antiBodies (MABs) from elderly individuals. We found that they were Broadly reactive within the B/Victoria/2/1987-like lineage, and two were highly cross-reactive with B/Yamagata/16/1988-like lineage Viruses. The MABs were found to Be neutralizing, to utilize Fc effector functions, and to Be protective against lethal viral challenge in a mouse model. In order to identify residues on the <B>InfluenzaB> B Virus hemagglutinin interacting with the MABs, we generated escape mutant Viruses. Interestingly, escape from these MABs led to numerous HA mutations within the head domain, including in the defined antigenic sites. We oBserved that each individual escape mutant Virus was aBle to avoid neutralization By its respective MAB along with other MABs in the panel, although in many cases Binding activity was maintained. Point mutant Viruses indicated that K90 is critical for the neutralization of two MABs, while escape from the other two MABs required a comBination of mutations in the hemagglutinin. Three of four escape mutant Viruses had increased lethality in the DBA2/J mouse model. Our work indicates that these cross-reactive antiBodies have the potential to cause antigenic drift in the viral population By driving mutations that increase Virus fitness. However, Binding activity and cross-neutralization were maintained By a majority of antiBodies in the panel, suggesting that this drift may not lead to escape from antiBody-mediated protection.IMPORTANCE Understanding the immune response that older individuals mount to <B>InfluenzaB> Virus vaccination and infection is critical in order to design Better vaccines for this age group. Here, we show that older individuals make Broadly neutralizing antiBodies that have no hemagglutination-inhiBiting activity and are less potent than strain-specific antiBodies. These antiBodies could drive viral escape from neutralization But did not result in escape from Binding. Given their different mechanisms of action, they might retain protective activity even against escape variants.
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Broadly cross reactive nonneutralizing antiBodies against <B>InfluenzaB> B Virus hemagglutinin demonstrate effector function dependent protection against lethal viral challenge in mice
Journal of Virology, 2019Co-Authors: Guha Asthagiri Arunkumar, Andriani Ioannou, Teddy John Wohlbold, Philip Meade, Sadaf Aslam, Fatima Amanat, Juan Ayllon, Adolfo Garciasastre, Florian KrammerAbstract:Protection from <B>InfluenzaB> Virus infection is canonically associated with antiBodies that neutralize the Virus By Blocking the interaction Between the viral hemagglutinin and host cell receptors. However, protection can also Be conferred By other mechanisms, including antiBody-mediated effector functions. Here, we report the characterization of 22 Broadly cross-reactive, nonneutralizing antiBodies specific for <B>InfluenzaB> B Virus hemagglutinin. The majority of these antiBodies recognized <B>InfluenzaB> B Viruses isolated over the period of 73 years and Bind the conserved stalk domain of the hemagglutinin. A proportion of the characterized antiBodies protected mice from Both morBidity and mortality after challenge with a lethal dose of <B>InfluenzaB> B Virus. Activity in an antiBody-dependent cell-mediated cytotoxicity reporter assay correlated strongly with protection, suggesting that Fc-dependent effector function determines protective efficacy. The information regarding mechanism of action and epitope location stemming from our characterization of these antiBodies will inform the design of urgently needed vaccines that could induce Broad protection against <B>InfluenzaB> B Viruses. IMPORTANCE While Broadly protective antiBodies against the <B>InfluenzaB> A Virus hemagglutinin have Been well studied, very limited information is availaBle for antiBodies that Broadly recognize <B>InfluenzaB> B Viruses. Similarly, the development of a universal or Broadly protective <B>InfluenzaB> B Virus vaccine lags Behind the development of such a vaccine for <B>InfluenzaB> A Virus. More information aBout epitope location and mechanism of action of Broadly protective <B>InfluenzaB> B Virus antiBodies is required to inform vaccine development. In addition, protective antiBodies could Be a useful tool to treat or prevent <B>InfluenzaB> B Virus infection in pediatric cohorts or in a therapeutic setting in immunocompromised individuals in conjugation with existing treatment avenues.
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primary human <B>InfluenzaB> B Virus infection induces cross lineage hemagglutinin stalk specific antiBodies mediating antiBody dependent cellular cytoxicity
The Journal of Infectious Diseases, 2018Co-Authors: Rory D De Vries, Florian Krammer, Nella J Nieuwkoop, Fiona R M Van Der Klis, Marion Koopmans, Guus F RimmelzwaanAbstract:<B>InfluenzaB> A Virus (IAV) and <B>InfluenzaB> B Virus (IBV) cause suBstantial morBidity and mortality during annual epidemics. Two distinct lineages of IBV are distinguished, Based on variation in hemagglutinin (HA): B/Victoria/2/87-like (B/Vic) and B/Yamagata/16/88-like (B/Yam). Here, we show that, in humans, primary IBV infection with either lineage induces HA-specific antiBody-dependent cellular cytotoxicity (ADCC)-mediating antiBodies. IBV infection induced antiBodies specific to the HA head and stalk, But only HA stalk-specific antiBodies mediated ADCC efficiently and displayed cross-reactivity with IBV of Both lineages. This corresponds to recent findings that 2 points of contact Between the effector and target cell (ie, HA and sialic acid, respectively, and the fragment crystallizaBle [Fc] domain and Fcγ receptor IIIα, respectively) are required for efficient ADCC activity and that antiBodies specific for the receptor-Binding site located in the head domain of HA therefore fail to mediate ADCC. Potentially, ADCC-mediating antiBodies directed to the HA stalk of IBV contriBute to cross-protective immunity to IBV of Both lineages.
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generation of a serum free cho dg44 cell line staBly producing a Broadly protective anti <B>InfluenzaB> Virus monoclonal antiBody
PLOS ONE, 2017Co-Authors: Veronika Chromikova, Maria A Zaragoza, Florian KrammerAbstract:Because of the Broad neutralization and in vivo protection across <B>InfluenzaB> A and <B>InfluenzaB> B Virus strains, monoclonal antiBody CR9114 is widely used in <B>InfluenzaB> Virus research as a positive control in many experiments. To produce amounts sufficient for the demand requires regular transient transfections, resulting in varying yield as well as differing Batch to Batch quality. Here, we report the development of a serum-free CHO DG44 cell line, staBly producing a CR9114-like antiBody with a potential to Become a useful <B>InfluenzaB> Virus research tool.
Robert G Webster - One of the best experts on this subject based on the ideXlab platform.
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rescue of <B>InfluenzaB> B Virus from eight plasmids
Proceedings of the National Academy of Sciences of the United States of America, 2002Co-Authors: Erich Hoffmann, Robert G Webster, Kutubuddin Mahmood, Chinfen Yang, Harry B Greenberg, George KembleAbstract:<B>InfluenzaB> B Virus causes a significant amount of morBidity and mortality, yet the systems to produce high yield inactivated vaccines for these Viruses have lagged Behind the development of those for <B>InfluenzaB> A Virus. We have estaBlished a plasmid-only reverse genetics system for the generation of recomBinant <B>InfluenzaB> B Virus that facilitates the generation of vaccine Viruses without the need for time consuming coinfection and selection procedures currently required to produce reassortants. We cloned the eight viral cDNAs of <B>InfluenzaB> B/Yamanashi/166/98, which yields relatively high titers in emBryonated chicken eggs, Between RNA polymerase I and RNA polymerase II transcription units. Virus was detected as early as 3 days after transfection of cocultured COS7 and Madin-DarBy canine kidney cells and achieved levels of 10(6)-10(7) plaque-forming units per ml of cell supernatant 6 days after transfection. The full-length sequence of the recomBinant Virus after passage into emBryonated chicken eggs was identical to that of the input plasmids. To improve the utility of the eight-plasmid system for generating 6 + 2 reassortants from recently circulating <B>InfluenzaB> B strains, we optimized the reverse transcriptase-PCR for cloning of the hemagglutinin (HA) and neuraminidase (NA) segments. The six internal genes of B/Yamanashi/166/98 were used as the BackBone to generate 6 + 2 reassortants including the HA and NA gene segments from B/Victoria/504/2000, B/Hong Kong/330/2001, and B/Hawaii/10/2001. Our results demonstrate that the eight-plasmid system can Be used for the generation of high yields of <B>InfluenzaB> B Virus vaccines expressing current HA and NA glycoproteins from either of the two lineages of <B>InfluenzaB> B Virus.
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<B>InfluenzaB> B Virus encephalitis
Clinical Infectious Diseases, 1999Co-Authors: Jonathan A Mccullers, Sergio Facchini, Joan P Chesney, Robert G WebsterAbstract:Acute encephalitis and postinfectious encephalopathy have Been reported infrequently in association with <B>InfluenzaB> A and B Virus infections. We report herein a case of a 6-year-old girl with acute <B>InfluenzaB> B Virus encephalitis resulting in neurological sequelae. The diagnosis was made By isolation of <B>InfluenzaB> B Virus from the nasopharynx, seroconversion to <B>InfluenzaB> B, and reverse transcription polymerase chain reaction (RT-PCR) identification of the Virus from the patient's cereBrospinal fluid. Direct sequencing of viral RNA from the patient's nasopharynx and cereBrospinal fluid revealed identical nucleotide sequences in the HA1 region of the hemagglutinin gene. This is the first report of <B>InfluenzaB> B Virus encephalitis diagnosed By use of RT-PCR and illustrates the need for increased awareness of <B>InfluenzaB> Virus as a cause of acute encephalitis. PCR may Be a useful tool for diagnosing future cases.
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evidence for zanamivir resistance in an immunocompromised child infected with <B>InfluenzaB> B Virus
The Journal of Infectious Diseases, 1998Co-Authors: Larisa V Gubareva, Richard C. Bethell, Mikhail Matrosovich, Malcolm K Brenner, Robert G WebsterAbstract:Zanamivir, a neuraminidase inhiBitor, has shown promise as a drug to control <B>InfluenzaB>. During prolonged treatment with zanamivir, a mutant Virus was isolated from an immunocompromised child infected with <B>InfluenzaB> B Virus. A hemagglutinin mutation (198 ThrrIle) reduced the Virus affinity for receptors found on susceptiBle human cells. A mutation in the neuraminidase active site (152 ArgrLys) led to a 1000-fold reduction in the enzyme sensitivity to zanamivir. When tested in ferrets, the mutant Virus had less virulence than the parent; however, it had a growth preference over the parent in zanamivir-treated animals. Despite these changes, the sensitivity of the mutant Virus to zanamivir assessed By a standard test in MDCK cells was unaffected. These data indicate that the current methods for monitoring resistant mutants are potentially flawed Because no tissue culture system adequately reflects the receptor specificity of human respiratory tract epithelium. <B>InfluenzaB> infection is associated with significant morBidity and mortality. Amantadine and rimantadine are the only drugs approved for <B>InfluenzaB> prophylaxis and treatment. However, they are ineffective against <B>InfluenzaB> B Virus infection, can cause significant adverse side effects, and readily select resistant mutants [1]. A novel inhiBitor of an <B>InfluenzaB> neuraminidase (NA), zanamivir (4-guanidino-Neu5Ac2en), has demonstrated significant antiviral effect in animal models [2] and in human studies [3, 4] and is currently in clinical development for the prophylaxis and treatment of <B>InfluenzaB> A and B infection. While multiple passages were required to select zanamivir-resistant mutants in vitro [5‐7], there have Been no reports on selection of such mutants in in vivo studies. It is well recognized that immunosuppression enhances the opportunity for viral replication to occur for extended periods and therefore provides a suitaBle environment for the emergence of drug-resistant mutants. Here we present evidence for resistance of <B>InfluenzaB> B Virus that emerged after zanamivir treatment of a Bone marrow recipient and descriBe the properties of the mutant Virus.
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evidence for zanamivir resistance in an immunocompromised child infected with <B>InfluenzaB> B Virus
The Journal of Infectious Diseases, 1998Co-Authors: Larisa V Gubareva, Richard C. Bethell, Mikhail Matrosovich, Malcolm K Brenner, Robert G WebsterAbstract:Zanamivir, a neuraminidase inhiBitor, has shown promise as a drug to control <B>InfluenzaB>. During prolonged treatment with zanamivir, a mutant Virus was isolated from an immunocompromised child infected with <B>InfluenzaB> B Virus. A hemagglutinin mutation (198 Thr-->Ile) reduced the Virus affinity for receptors found on susceptiBle human cells. A mutation in the neuraminidase active site (152 Arg-->Lys) led to a 1000-fold reduction in the enzyme sensitivity to zanamivir. When tested in ferrets, the mutant Virus had less virulence than the parent; however, it had a growth preference over the parent in zanamivir-treated animals. Despite these changes, the sensitivity of the mutant Virus to zanamivir assessed By a standard test in MDCK cells was unaffected. These data indicate that the current methods for monitoring resistant mutants are potentially flawed Because no tissue culture system adequately reflects the receptor specificity of human respiratory tract epithelium.