S Norley

Robert Koch Institut, Berlín, Berlin, Germany

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Publications (39)124.73 Total impact

  • No preview · Conference Paper · Oct 2010
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    ABSTRACT: DNA electroporation is a powerful vaccine strategy that could be rapidly adapted to address emerging viruses. We therefore compared cellular and humoral immune responses in mice vaccinated with DNA expression plasmids encoding either the wildtype or a codon-optimized sequence of hemagglutinin from the novel swine origin H1N1 influenza virus. While expression of HA from the wildtype sequence was hardly detectable, the H1N1 hemagglutinin was well expressed from the codon-optimized sequence. Despite poor expression of the wildtype sequence, both plasmids induced similar levels of CD4(+) T-cell responses. However, CD8(+) T-cell and antibody responses were substantially higher after immunization with the codon-optimized DNA vaccine. Thus, efficient induction of immune effector mechanisms against HA of the novel H1N1 influenza virus requires codon-optimization of the DNA vaccines. Since DNA vaccines and several viral vector vaccines employ the same cellular RNA-Polymerase II dependent expression pathway, the poor expression levels from wildtype HA sequences might also limit the induction of immune effector mechanisms by such viral vector vaccines.
    No preview · Article · Mar 2010 · Vaccine
  • R Behrendt · U Fiebig · S Norley · L Gürtler · R Kurth · J Denner
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    ABSTRACT: Specific, effective and rapid neutralization assays are crucial for the development of an HIV vaccine based on the stimulation of neutralizing antibodies and the development of such an assay for the human immunodeficiency virus-2 (HIV-2) is described. Virus neutralization was measured as the reduction of provirus integration using a duplex real-time PCR with high efficiency (99.4%). This PCR uses primers and a probe specific for the proviral LTR. Amplification and quantitative analysis of the cellular GAPDH gene was carried out in parallel to control for toxic or growth-inhibitory components in the sera. The neutralization assay was used to screen sera from 23 HIV-2 infected patients. 21 sera were able to neutralize HIV-2(60415K), 20 sera neutralized HIV-2(7312A) and 7 sera cross-neutralized HIV-1 IIIB. In contrast, when 14 of these sera were tested in parallel with a conventional neutralization assay based on a p27Gag capture ELISA, only one was found to neutralize HIV-2(60415K) and 11 to neutralize HIV-2(7312A) compared with 12 and 13 sera respectively using the PCR-based assay.
    No preview · Article · Aug 2009 · Journal of virological methods
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    ABSTRACT: A new challenge stock of the simian immunodeficiency virus SIVmacJ5 has been produced following passage in vivo. SIVmacJ5 3/92 (J5M), was passaged serially through cynomolgus macaques (Macaca fascicularis) by intravenous inoculation of infected spleen cells isolated and prepared 14 days post-infection. Two challenge stocks, SIVmacJ5 S61MLN and SIVmacJ5 S62spl, were prepared by culture of lymphoid tissue ex vivo. These virus stocks appeared better adapted for replication in M. fascicularis as demonstrated by a greater persistence of recoverable live virus from the periphery and increased pathology in lymphoid tissues 20 weeks post-challenge as detected by immunohistochemistry. Sequence analysis of the envelope gene from these stocks did not identify marked diversification of sequence as a result of this procedure. These stocks display more robust peripheral persistence and tissue pathology in cynomolgus macaques and should prove valuable analysing recombinant vaccines based upon SIVmacJ5 transgenes.
    Full-text · Article · Jul 2007 · Journal of Medical Primatology
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    ABSTRACT: Vaccination with exogenous antigens such as recombinant viral proteins, immunodeficiency virus-derived whole inactivated virus particles, or virus-like particles (VLP) has generally failed to provide sufficient protection in animal models for AIDS. Pseudotyping VLPs with the vesicular stomatitis virus G protein (VSV-G), which is known to mediate entry into dendritic cells, might allow more efficient stimulation of immune responses. Therefore, we pseudotyped noninfectious immunodeficiency virus-like particles with VSV-G and carried out a preliminary screen of their immunogenicity and vaccination efficacy. Incorporation of VSV-G into HIV-1 VLPs led to hundred-fold higher antibody titers to HIV-1 Gag and enhancement of T cell responses in mice. Repeated vaccination of rhesus monkeys for 65 weeks with VSV-G pseudotyped simian immunodeficiency virus (SIV)-like particles (VLP[G]) provided initial evidence for efficient suppression of viral load after mucosal challenge with the SIVmac239 virus. Challenge of monkeys after a 28 week vaccination regimen with VLP[G] led to a reduction in peak viremia, but persistent suppression of viral load was not achieved. Due to limitations in the number of animals available for this study, improved efficacy of VSV-G pseudotyped VLPs in nonhuman primates could not be demonstrated. However, mouse experiments revealed that pseudotyping of VLPs with fusion-competent VSV-G clearly improves their immunogenicity. Additional strategies, particularly adjuvants, should be considered to provide greater protection against a challenge with pathogenic immunodeficiency virus.
    Full-text · Article · Aug 2006 · Virology
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    ABSTRACT: Candidate human immunodeficiency virus (HIV) vaccine strategies that induce strong cellular immune responses protect rhesus macaques that are infected with recombinant simian/human immunodeficiency virus SHIV89.6p from acute CD4+ T-cell loss and delay progression to AIDS. However, similar strategies have not proven as efficacious in the simian immunodeficiency virus (SIV)mac model of AIDS, an infection that causes a slow, steady loss of CD4+ T-cell function and numbers in rhesus macaques similar to that caused by HIV-1, the principal cause of AIDS in humans. Efforts to increase vaccine efficacy by repeated boosting with the same vector are quickly limited by rising anti-vector immune responses. Here, the sequential use of three different vectors (DNA, Semliki Forest virus and modified vaccinia virus Ankara) encoding the same SIVmac structural and regulatory antigens was investigated and demonstrated to prevent or slow the loss of CD4+ T-cells after mucosal challenge with the highly pathogenic SIVmac251 strain. Of particular interest was an inverse association between the extent of T-helper 2 cytokine responses and steady-state virus load. Although limited in the number of animals, this study provides important proof of the efficacy of the triple-vector vaccine strategy against chronic, progressive CD4+ T-cell loss in the rigorous SIVmac/rhesus macaque model of AIDS.
    Full-text · Article · Nov 2004 · Journal of General Virology
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    ABSTRACT: A brain homogenate prepared from a terminally ill hamster infected with scrapie strain 263K was serially diluted and administered orally to groups of hamsters. The undiluted brain homogenate led to clinical scrapie in all animals inoculated. The attack rate decreased with dilutions of the homogenate, and subclinical infections were identified among the healthy survivors at 520 days post-infection by Western blotting. The number of animals succumbing to disease and the combined number of Western blot-positive survivors plus diseased hamsters were used to calculate the LD(50) and ID(50) of the inoculum. The model system represents an approximation to the transmission of TSEs such as new variant Creutzfeldt-Jakob disease (vCJD) via dietary exposure to the infectious agent and suggests that, due to the rather small difference between the calculated LD(50) and ID(50), the number of clinical cases will not be vastly exceeded by the number of subclinical carriers of the disease.
    Full-text · Article · Aug 2003 · Journal of General Virology
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    ABSTRACT: The efficacy of a multicomponent vaccination with modified vaccinia Ankara constructs (rMVA) expressing structural and regulatory genes of simian immunodeficiency virus (SIV(mac251/32H/J5)) was investigated in cynomolgus monkeys, following challenge with a pathogenic SIV. Vaccination with rMVA-J5 performed at week 0, 12, and 24 induced a moderate proliferative response to whole SIV, a detectable humoral response to all but Nef SIV antigens, and failed to induce neutralizing antibodies. Two months after the last boost, the monkeys were challenged intravenously with 50 MID50 of SIV(mac251). All control monkeys, previously inoculated with non-recombinant MVA, were infected by week two and seroconverted by weeks four to eight. In contrast a sharp increase of both humoral and proliferative responses at two weeks post-challenge was observed in vaccinated monkeys compared to control monkeys. Although all vaccinated monkeys were infected, vaccination with rMVA-J5 appeared to partially control viral replication during the acute and late phase of infection as judged by cell- and plasma-associated viral load.
    No preview · Article · Sep 2001 · Journal of Medical Primatology
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    ABSTRACT: Interleukin-16 (IL-16) acts as a chemoattractant for CD4+ cells, as a modulator of T-cell activation, and plays a key role in asthma. This report describes the cytokine-inducing effects of IL-16 on total peripheral blood mononuclear cells (PBMC) and PBMC subpopulations. While CD4+ T lymphocytes did not secrete cytokines in response to rhIL-16, CD14+ CD4+ monocytes and maturing macrophages secrete IL-1beta, IL-6, IL-15 and tumour necrosis factor-alpha (TNF-alpha) upon rhIL-16 stimulation. The mRNA species for these four cytokines were detected as early as 4 hr post-stimulation, with protein being secreted by 24 hr. Secretion of IL-1beta and IL-6 by total PBMC was dose dependent, with maximal secretion being observed using 50 ng/ml rhIL-16. However, for IL-15 or TNF-alpha maximal secretion by total PBMC occurred with all concentrations between 5 ng/ml to 500 ng/ml rhIL-16. Purified monocytes/macrophages secreted maximal concentrations of all four cytokines in the presence of 500 ng/ml rhIL-16, except for monocytes where maximal secretion of IL-15 was, interestingly, observed with only 50 ng/ml rhIL-16. The use of higher concentrations of rhIL-16 (1000 ng/ml) inhibited secretion of all four cytokines. While these IL-16-induced cytokines are likely to be involved in the immune system's response to antigen, the data suggest that IL-16 may play a key role in initiating and/or sustaining an inflammatory response.
    Preview · Article · Jun 2000 · Immunology
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    ABSTRACT: Primate gamma-2 herpesviruses (rhadinoviruses) have so far been found in humans (Kaposi's sarcoma-associated herpesvirus [KSHV], also called human herpesvirus 8), macaques (Macaca spp.) (rhesus rhadinovirus [RRV] and retroperitoneal fibromatosis herpesvirus [RFHV]), squirrel monkeys (Saimiri sciureus) (herpesvirus saimiri), and spider monkeys (Ateles spp.) (herpesvirus ateles). Using serological screening and degenerate consensus primer PCR for the viral DNA polymerase gene, we have detected sequences from two distinct gamma-2 herpesviruses, termedChlorocebus rhadinovirus 1 (ChRV1) and ChRV2, in African green monkeys. ChRV1 is more closely related to KSHV and RFHV, whereas ChRV2 is closest to RRV. Our findings suggest the existence of two distinct rhadinovirus lineages, represented by the KSHV/RFHV/ChRV1 group and the RRV/ChRV2 group, respectively, in at least two Old World monkey species. Antibodies to members of the RRV/ChRV2 lineage may cross-react in an immunofluorescence assay for early and late KSHV antigens.
    Full-text · Article · Mar 2000 · Journal of Virology
  • S Norley · B Beer · S Holzammer · J zur Megede · R Kurth
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    ABSTRACT: An increasing number of African primate species have been shown to be infected in the wild with their own distinct variants of simian immunodeficiency virus. The most striking feature of these natural host systems is the lack of AIDS-like disease despite long-term infection. In the African green monkey (AGM)/SIVagm system there is no evidence that a vigorous antiviral immune response, a lack of variability or a low virus load accounts for this lack of pathogenicity. New-born AGMs appear to be even more resistant to the virus than adults, despite their immature immune system and higher pool of target cells. The fact that AGMs, unlike HIV-infected humans, lack a humoral immune response to non-denatured Gag protein and do not show trapping of virus in the lymph nodes suggested that tolerance to Gag might prevent the formation of immune complexes which would normally be filtered out by the lymphoid tissues with detrimental results. This apparent tolerance to Gag is a common feature of many, if not all, of the natural host systems and might explain why the lymph nodes and immune system in general remain intact in these primates in the face of continuous, high level virus replication.
    No preview · Article · Apr 1999 · Immunology Letters
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    ABSTRACT: The aim of the study was to select, from a panel of candidate European human immunodeficiency virus type 1 (HIV-1) clade B primary virus isolates, one isolate based on replication properties in chimpanzee peripheral blood mononuclear cells (PBMC). Secondly, to evaluate the in vivo kinetics of primary infection of the selected isolate at two different doses in two mature, outbred chimpanzees (Pan troglodytes). Four different low passage, human PBMC-cultured 'primary' HIV-1 isolates with European clade B consensus sequence were compared for their ability to replicate in vitro in chimpanzee versus human PBMC. The isolate which yielded the highest titre and most vigorous cytopathic effect in chimpanzee PBMC was evaluated for coreceptor usage and chosen for evaluation in vivo. Only the HIV-1Han2 isolate replicated in chimpanzee PBMC in vitro at detectable levels. This isolate was demonstrated to utilize CCR4, CCR5 and CXCR4 coreceptors and could be inhibited by beta-chemokines. Infection of chimpanzees was demonstrated by viral RNA and DNA PCR analysis, both in plasma as well as in PBMC and lymph node cells as early as 3 weeks after inoculation. Antibodies developed within 6 weeks and continued to increase to a maximum titre of approximately 12800, thereafter remaining in this range over the follow-up period of 2 years. Compared to cell line-adapted HIV-1 isolates there were slight but no dramatic differences in the kinetics of infection of chimpanzees with this particular primary isolate.
    Full-text · Article · Jan 1999 · Journal of General Virology
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    ABSTRACT: Infection of macaques with attenuated simian immunodeficiency virus (SIV) induces potent superinfection resistance that may be applicable to the development of an AIDS vaccine but little information exists concerning the conditions necessary for the induction of this vaccine effect. We report that only a high dose of attenuated SIVmac protected macaques against intravenous challenge with more virulent virus 15 weeks after primary infection. Three of four animals given 2000-20000 TCID50 of SIVmacC8, a molecular clone of SIVmac251(32H) with a 12 bp deletion in the nef gene, essentially resisted superinfection with uncloned SIVmac. In two animals challenge virus was never detected by PCR and in one animal challenge virus was detected on one occasion only. Although animals given 2-200 TCID50 of attenuated virus were superinfected they were spared from the loss of CD4 cells seen in infected naive controls. Protection from superinfection did not correlate with immune responses, including the levels of virus-specific antibodies or virus-neutralizing activity measured on the day of challenge; although, after superinfection challenge, Nef-specific CTL responses were detected only in animals infected with high doses of attenuated SIV. Unexpectedly, cell-associated virus loads 2 weeks after inoculation were significantly lower in animals infected with a high dose of attenuated SIV compared to those in animals infected with a low dose. Our results suggest that the early dynamics of infection with attenuated virus influence superinfection resistance.
    Preview · Article · Sep 1998 · Journal of General Virology
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    ABSTRACT: Factors secreted by CD8(+) T cells have been described to suppress immunodeficiency virus replication. The research efforts to identify these factors led to the proposal of some candidate proteins as being responsible for the antiviral effects. Chemokines and IL-16 are secreted by CD8(+) T cells and inhibit HIV replication through different mechanisms. However, their antiviral properties cannot fully explain the inhibitory activities found in cell culture supernatants from CD8(+) T cells.
    No preview · Article · Feb 1998 · Pathobiology
  • J Denner · C Persin · T Vogel · D Haustein · S Norley · R Kurth
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    ABSTRACT: The transmembrane glycoproteins of all retroviruses contain a conserved region composed of a leucine zipper, an immunosuppressive domain, and an immunodominant Cys-Cys loop. The amino acid sequence of the immunosuppressive domain of gp41 of human immunodeficiency virus type 1 (HIV-1; amino acids 583-599) is closely related, but not identical, to the immunosuppressive domains of type C and D retroviruses. A synthetic peptide corresponding to the immunosuppressive domain of HIV-1 (immunosuppressive peptide, ISU-peptide) inhibits mitogen and lymphokine stimulation of T lymphocytes. It is interspecies reactive and inhibits both human and mouse lymphocytes. The inhibitory effect is not based on direct cytotoxicity and the peptide is immunosuppressive only when conjugated to a carrier protein. The ISU-peptide of HIV-1 also inhibits B lymphocyte stimulation by the B cell mitogen lipopolysaccharide and by specific antibodies against delta and mu chains of cell surface immunoglobulins. These data suggest that the immunosuppressive domain of gp41 may play an important role in the immunopathogenesis of AIDS.
    No preview · Article · Sep 1996 · Journal of Acquired Immune Deficiency Syndromes and Human Retrovirology
  • B Beer · S Norley · K Cichutek · R Kurth

    No preview · Article · Jul 1996 · AIDS

  • No preview · Article · Apr 1996 · AIDS Research and Human Retroviruses
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    ABSTRACT: By studying the infection of rhesus macaques with simian immunodeficiency virus (SIVmac) the potential of nucleic acid immunisation against AIDS can be evaluated. As a first step towards the development of suitable expression constructs, the levels and the durations of expression elicited by the house-keeping gene promoters of the murine phospho-glycerate kinase (PGK) gene and rat proto-ras 1Ha, a lentiviral LTR and the CMV-intron A promoter were tested in BALB/c mice intramuscularly inoculated with marker gene constructs encoding luciferase. The expression levels achieved by the CMV-intron A and the lentiviral promoter were comparably high, and also the PGK promoter induced a high level of expression for at least 64 days. Following the inoculation of plasmids comprising single or multiple genes of SIV, the induction of specific antibodies directed against SIV antigens was demonstrated. We previously showed in vitro that int- and nef-defective mutants of SIVmac were able to initiate a limited and self-abortive infection of permissive cells in the absence of chromosomal integration of the viral DNA. Intramuscular inoculations in monkeys using int-defective proviral DNA of SIV will show whether an increased immune response may be induced by expression of viruses undergoing a self-limited replication in vivo.
    No preview · Article · Feb 1996 · Journal of Biotechnology
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    T Vogel · S Norley · B Beer · R Kurth
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    ABSTRACT: As part of an ongoing vaccine study using peptide immunogens designed to stimulate simian immunodeficiency virus (SIV)mac-specific cytotoxic T lymphocytes (CTL) it was necessary to identify rhesus macaques within our colony bearing the Mamu-A1 major histocompatibility complex (MHC) class I haplotype. Peripheral blood mononuclear cells (PBMC) from individual monkeys were analysed by immunoelectrofocusing for the presence of a band corresponding to the Mamu-A1 molecule. In addition, PBMC were pulsed with the SIVmac Gag peptide 11 (against which CTL are Mamu-A1 restricted) and analysed for susceptibility to lysis by peptide 11-specific CTL. PBMC from all of the rhesus macaques shown to be Mamu-A1 positive by immunoelectrofocusing were highly sensitive to lysis by the peptide 11-specific CTL. A total of 46% (16 from 35) of the rhesus macaques originating from India were found to be Mamu-A1 positive, whereas none of the Chinese rhesus (0 from 37) macaques possessed this haplotype. Once a peptide-specific CTL is established, screening by CTL assay offers a faster, reliable and more relevant alternative to immunoelectrofocusing for selecting monkeys for use in vaccination trials.
    Full-text · Article · Apr 1995 · Immunology
  • J. Denner · T. Vogel · S. Norley · A. Hoffmann · R. Kurth
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    ABSTRACT: Without Abstract
    No preview · Article · Dec 1994 · Journal of Cancer Research and Clinical Oncology

Publication Stats

923 Citations
124.73 Total Impact Points


  • 2001-2010
    • Robert Koch Institut
      • • Division 18: Centre for HIV and Retrovirology
      • • Project 23: Neurodegenerative Diseases
      Berlín, Berlin, Germany
  • 1991-2000
    • Paul-Ehrlich-Institut
      • Research Unit for Molecular Biotechnology and Gene Therapy
      Langen, Hesse, Germany
  • 1994
    • Biomedical primate research centre
      Rijswijk, South Holland, Netherlands