Urban Lundberg

Intercell, Wien, Vienna, Austria

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Publications (18)86.48 Total impact

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    ABSTRACT: There is currently no Lyme borreliosis vaccine available for humans, although it has been shown that the disease can be prevented by immunization with an OspA-based vaccine (LYMErix). Outer surface protein A (OspA) is one of the dominant antigens expressed by the spirochetes when present in a tick. The Borrelia species causing Lyme borreliosis in Europe express different OspA serotypes on their surface, B. burgdorferi (serotype 1), B. afzelii (serotype 2), B. garinii (serotypes, 3, 5 and 6) and B. bavariensis (serotype 4), while only B. burgdorferi is present in the US. In order to target all these pathogenic Borrelia species, we have designed a multivalent OspA-based vaccine. The vaccine includes three proteins, each containing the C-terminal half of two OspA serotypes linked to form a heterodimer. In order to stabilize the C-terminal fragment and thus preserve important structural epitopes at physiological temperature, disulfide bonds were introduced. The immunogenicity was increased by introduction of a lipidation signal which ensures the addition of an N-terminal lipid moiety. Three immunizations with 3.0 µg adjuvanted vaccine protected mice from a challenge with spirochetes expressing either OspA serotype 1, 2 or 5. Mice were protected against both challenge with infected ticks and in vitro grown spirochetes. Immunological analyses (ELISA, surface binding and growth inhibition) indicated that the vaccine can provide protection against the majority of Borrelia species pathogenic for humans. This article presents the approach which allows for the generation of a hexavalent vaccine that can potentially protect against a broad range of globally distributed Borrelia species causing Lyme borreliosis.
    PLoS ONE 11/2014; 9(11):e113294. DOI:10.1371/journal.pone.0113294 · 3.53 Impact Factor
  • 01/2014; 4(Suppl 2):O18. DOI:10.1186/2045-7022-4-S2-O18
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    ABSTRACT: Dry tetanus toxoid (TTx) patches were formulated without any adjuvant, with excipients to impart antigen stabilization and to enhance skin delivery. The booster effects of the TTx patches were assessed in a guinea pig model. The study revealed significant rises in TTx IgG titers by the TTx patches after a low-dose s.c. prime with TTx adsorbed to aluminum hydroxide. The TTx patch can therefore be considered as an effective alternative to a subcutaneous booster.
    Clinical and vaccine Immunology: CVI 12/2013; DOI:10.1128/CVI.00638-13 · 2.37 Impact Factor
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    ABSTRACT: Moraxella catarrhalis is one of the three most common causative bacterial pathogens of otitis media, however no effective vaccine against M. catarrhalis has been developed so far. To identify M. catarrhalis vaccine candidate antigens, we used carefully selected sera from children with otitis media and healthy individuals to screen small-fragment genomic libraries that are expressed to display frame-selected peptides on a bacterial cell surface. This ANTIGENome technology led to the identification of 214 antigens, 23 of which were selected by in vitro or in vivo studies for additional characterization. Eight of the 23 candidates were tested in a Moraxella mouse pulmonary clearance model, and 3 of these antigens induced significantly faster bacterial clearance compared to adjuvant or to the previously characterized antigen OmpCD. The most significant protection data were obtained with the antigen MCR_1416 (Msp22), which was further investigated for its biological function by in vitro studies suggesting that Msp22 is a heme binding protein. This study comprises one of the most exhaustive studies to identify potential vaccine candidate antigens against the bacterial pathogen M. catarrhalis.
    PLoS ONE 05/2013; 8(5):e64422. DOI:10.1371/journal.pone.0064422 · 3.53 Impact Factor
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    ABSTRACT: Nosocomial infections, also called "hospital acquired infections," occur worldwide and affect both developed and resource-poor countries, thus having a major impact on their health care systems. Klebsiella pneumoniae, which is an opportunistic Gram-negative pathogen, is responsible for causing pneumonia, urinary tract infections and septicemia in immune compromised hosts such as neonates. Unfortunately, there is no vaccine or mAb available for prophylactic or therapeutic use against K. pneumoniae infections. For this reason, we sought for a protein-based subunit vaccine capable of combating K. pneumoniae infections, by applying our ANTIGENome technology for the identification of potential vaccine candidates, focusing on conserved protein antigens present in strains with different serotypes. We identified numerous novel immunogenic proteins using genomic surface display libraries and human serum antibodies from donors exposed to or infected by K. pneumoniae. Vaccine candidate antigens were finally selected based on animal protection in a murine lethal-sepsis model. The protective and highly conserved antigens identified in this study are promising candidates for the development of a protein-based vaccine to prevent infection by K. pneumoniae.
    Human Vaccines & Immunotherapeutics 12/2012; 9(3). DOI:10.4161/hv.23225 · 3.64 Impact Factor
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    ABSTRACT: The versatility of the surface of Borrelia, the causative agent of Lyme borreliosis, is very important in host-pathogen interactions allowing bacteria to survive in ticks and to persist in a mammalian environment. To identify the surface proteome of Borrelia, we have performed a large comparative proteomic analysis on the three most important pathogenic Borrelia species, namely B. burgdorferi (strain B31), B. afzelii (strain K78), and B. garinii (strain PBi). Isolation of membrane proteins was performed by using three different approaches: (i) a detergent-based fractionation of outer membrane proteins; (ii) a trypsin-based partial shedding of outer cell surface proteins; (iii) biotinylation of membrane proteins and preparation of the biotin-labelled fraction using streptavidin. Proteins derived from the detergent-based fractionation were further sub-fractionated by heparin affinity chromatography since heparin-like molecules play an important role for microbial entry into human cells. All isolated proteins were analysed using either a gel-based liquid chromatography (LC)-MS/MS technique or by two-dimensional (2D)-LC-MS/MS resulting in the identification of 286 unique proteins. Ninety seven of these were found in all three Borrelia species, representing potential targets for a broad coverage vaccine for the prevention of Lyme borreliosis caused by the different Borrelia species.
    Proteomics 03/2012; 12(6):845-58. DOI:10.1002/pmic.201100211 · 3.97 Impact Factor
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    ABSTRACT: The three Borrelia species, Borrelia afzelii, Borrelia burgdorferi and Borrelia garinii are the main species causing the most common tick-borne zoonosis, Lyme borreliosis. By applying a genomic approach relying on human antibodies we have identified 122 antigenic Borrelia proteins associated with Lyme borreliosis, including already known and published protective antigens. The heterogeneity of the Borrelia species causing Lyme borreliosis makes the search for conserved antigens providing broad protection challenging. Using several in vitro assays we narrowed down the selection to 15 vaccine candidates. These antigens were further analyzed for antigenicity and cross-reactivity using sera from mice infected with the three pathogenic Borrelia species. All antigens analyzed showed a high degree of cross-reactivity between the three Borrelia species, essential for providing cross-protection. We also investigated whether mice infected with B. afzelii through tick exposure are primed to mount cytokine responses. For a selection of these antigens, we observed preferentially a pro-inflammatory response in C3H/HeN mice, while in contrast also a type 2 T cell response was seen in the Borrelia-resistant mouse strain BALB/c. Thus, antigens mounting a type 2 or mixed type 2/type 1 T cell response might be preferred vaccine candidates for evaluation in animal models of Lyme borreliosis.
    Vaccine 11/2011; 30(29):4398-406. DOI:10.1016/j.vaccine.2011.10.073 · 3.49 Impact Factor
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    ABSTRACT: Group B streptococcus remains an important neonatal pathogen in spite of widely adopted intrapartum antibiotic administration; therefore immune prophylaxis for GBS infections is highly warranted. In passive immunization and lethal challenge studies with multiple GBS strains, we characterized the protective effect of rabbit polyclonal and murine monoclonal antibodies specific for four multi-functional cell wall anchored proteins, FbsA, BibA, PilA and PilB. Single specificity rabbit sera or mAbs induced high level, but strain dependent protection, while their combinations resulted in superior and broad efficacy against all GBS strains tested. Polyclonal and monoclonal antibodies specific for the pilus proteins exerted very potent opsonophagocytic killing activity in vitro and required the Fc domain for protection in vivo. In contrast, FbsA and BibA specific antibodies failed to show OPK activity, but their Fab fragments fully protected animals, suggesting that blocking the function of these proteins was the major mode of action. These data are supportive for developing immune prophylaxis with human mAbs for prematurely born neonates who receive low levels of antibodies by maternofetal transport and are characterized by not fully developed phagocytic and complement activity.
    Vaccine 05/2011; 29(24):4116-24. DOI:10.1016/j.vaccine.2011.03.100 · 3.49 Impact Factor
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    ABSTRACT: Group B streptococcus is one of the most important pathogens in neonates, and causes invasive infections in non-pregnant adults with underlying diseases. Applying a genomic approach that relies on human antibodies we identified antigenic GBS proteins, among them most of the previously published protective antigens. In vitro analyses allowed the selection of conserved candidate antigens that were further evaluated in murine lethal sepsis models using several GBS strains. In active and passive immunization models, we identified four protective GBS antigens, FbsA and BibA, as well as two hypothetical proteins, all shown to contribute to virulence based on gene deletion mutants. These protective antigens have the potential to be components of novel vaccines or targets for passive immune prophylaxis against GBS disease.
    Vaccine 10/2010; 28(43):6997-7008. DOI:10.1016/j.vaccine.2010.08.041 · 3.49 Impact Factor
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    ABSTRACT: Pneumococcus is one of the most important human pathogens that causes life-threatening invasive diseases, especially at the extremities of age. Capsular polysaccharides (CPSs) are known to induce protective antibodies; however, it is not feasible to develop CPS-based vaccines that cover all of the 90 disease-causing serotypes. We applied a genomic approach and described the antibody repertoire for pneumococcal proteins using display libraries expressing 15-150 amino acid fragments of the pathogen's proteome. Serum antibodies of exposed, but not infected, individuals and convalescing patients identified the ANTIGENome of pneumococcus consisting of approximately 140 antigens, many of them surface exposed. Based on several in vitro assays, 18 novel candidates were preselected for animal studies, and 4 of them showed significant protection against lethal sepsis. Two lead vaccine candidates, protein required for cell wall separation of group B streptococcus (PcsB) and serine/threonine protein kinase (StkP), were found to be exceptionally conserved among clinical isolates (>99.5% identity) and cross-protective against four different serotypes in lethal sepsis and pneumonia models, and have important nonredundant functions in bacterial multiplication based on gene deletion studies. We describe for the first time opsonophagocytic killing activity for pneumococcal protein antigens. A vaccine containing PcsB and StkP is intended for the prevention of infections caused by all serotypes of pneumococcus in the elderly and in children.
    Journal of Experimental Medicine 01/2008; 205(1):117-31. DOI:10.1084/jem.20071168 · 13.91 Impact Factor
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    ABSTRACT: Invasive Salmonella has been reported to induce apoptosis in a fraction of infected macrophages within 2 to 14 h from the time of infection by a mechanism involving the type III secretion machinery encoded by the Salmonella pathogenicity island 1 (SPI-1). Here, we show that bacteria in the transition from logarithmic to stationary phase cause 90% of the macrophages to undergo phagocytosis-independent, caspase-mediated apoptosis within 30 to 60 min of infection. The ability of Salmonella to induce this rapid apoptosis was growth phase regulated and cell type restricted, with epithelial cells being resistant. Apoptosis induction was also abrogated by disruption of the hilA gene (encoding a regulator of SPI-1 genes) and by the expression of a constitutively active PhoPQ. hilA itself and a subset of SPI-1 genes were transiently expressed during aerobic growth in liquid medium. Interestingly, however, hilA was found to be required only for the expression of the prgH gene, while sipB, invA, and invF were expressed in a hilA-independent manner. The expression of SPI-1 genes and the secretion of invasion-associated proteins correlated temporally with the induction of apoptosis and are likely to represent its molecular basis. Thus, growth phase transition regulates the expression and secretion of virulence determinants and represents the most efficient environmental cue for apoptosis induction reported to date.
    Journal of Bacteriology 07/1999; 181(11):3433-7. · 2.69 Impact Factor
  • Molecular Microbiology 09/1995; 17(3):595-6. · 5.03 Impact Factor
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    ABSTRACT: The structure of untranslated regions of mRNA is thought to play a key role in the degradation of mRNAs by specific RNases. As a model system, in vitro transcripts of the stability determining 5' non-coding region of bacterial ompA mRNA were investigated by calculation of secondary structure models and by experiments applying the temperature-gradient gel electrophoresis (TGGE). For the theoretical prediction of secondary structures an algorithm was used, which yields the structure of lowest free energy as well as a large set of suboptimal structures. Three structures were predicted to co-exist in similar concentrations under native conditions. They denature in a low temperature transition leading to a unique structure which denatures in a high temperature transition. The prediction of three structures and two transitions could be confirmed experimentally by TGGE. Due to the use of transcripts of different length the conformational transitions could be attributed to distinct parts of the molecules. A pseudoknot structural motif was predicted theoretically, but could not be confirmed experimentally. Comparing ompA transcripts of E. coli and S. marcescens, a conservation of structural features could be shown in spite of a sequence homology of only 63%. Regarding the sequential folding of the transcript after synthesis, a metastable structure is formed first and is converted slowly into structures of lower free energy. The biological implications for in vivo degradation are discussed.
    Journal of Molecular Biology 03/1993; 229(3):656-70. DOI:10.1006/jmbi.1993.1070 · 3.96 Impact Factor
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    ABSTRACT: The highly specific endoribonuclease activities of RNase E (which processes ribosomal 9S RNA into p5S RNA) and RNase K (which initiates decay of the ompA mRNA) are inferred to play a central role in RNA processing and mRNA decay in Escherichia coli. In vivo both activities are affected by a conditional mutation of the ams/rne gene that seems to be complemented at nonpermissive temperatures by a fragment of the groEL gene. Analysis of the relationship between the two nucleases and the heat shock protein revealed that GroEL interacts functionally with an RNase E-like activity but not with an RNase K activity, a groEL mutation affected 9S RNA processing but not ompA mRNA cleavage, RNase E activity could be precipitated with an antibody against GroEL, and a highly purified GroEL preparation contained RNase E activity but not RNase K activity. When purifying RNase E activity, we obtained a preparation containing two major proteins of 60 and 17 kDa. The size and the N-terminal sequence identified the 60-kDa protein as GroEL.
    Proceedings of the National Academy of Sciences 02/1993; 90(1):277-81. DOI:10.1073/pnas.90.1.277 · 9.81 Impact Factor
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    U Lundberg, A von Gabain, O Melefors
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    ABSTRACT: We describe here the partial purification of a novel Escherichia coli endoribonuclease, RNase K. This protein catalyses site-specific cleavages in the 5' region of in vitro transcribed ompA and bla transcripts. Some of the resulting cleavage products are also found in cellular ompA mRNA, defining the in vivo activity of RNase K. The following evidence suggests that RNase K initiates mRNA degradation. First, RNase K cleavages are suppressed in the ams mutant, which has a generally prolonged mRNA half-life. Secondly, RNase K cleavage products seem to have very short half-lives in vivo, indicating that they are decay intermediates rather than processing products. Thirdly, the differences in in vivo half-life between the ompA and bla mRNAs are mimicked in in vitro decay reactions with purified RNase K. The relationship between RNase K and the ams locus might point to a more general role of RNase K in mRNA degradation. We discuss the influence of mRNA secondary structure on RNase K cleavage specificity.
    The EMBO Journal 10/1990; 9(9):2731-41. · 10.75 Impact Factor
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    ABSTRACT: Using two monocistronic gene transcripts, bla and ompA, we have studied the relationship between mRNA stability and translational efficiency. It was found that changes in the ompA mRNA stability are not correlated with an alteration in translational efficiency. In addition, at slow bacterial growth rates, the ompA transcript is translated ten times more efficiently than the bla messenger although the stability of the two transcripts is about equal. At rapid bacterial growth rate, chloramphenicol slightly stabilises both the bla and ompA transcripts without affecting their characteristic difference in half-life. Thus, control of mRNA stability seems not necessarily to be mediated either by the efficiency of loading ribosomes on a transcript, or by the arrest or slowing down of translating ribosomes.
    Gene 01/1989; 72(1-2):141-9. DOI:10.1016/0378-1119(88)90136-9 · 2.08 Impact Factor
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    G Nilsson, U Lundberg, A von Gabain
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    ABSTRACT: The bla and ompA gene transcripts were used as substrates to probe Escherichia coli extracts for ribonucleolytic activities. A site specific endoribonucleolytic activity was identified that cleaves ompA and bla mRNA. The cleavages occur in vitro and in vivo. For both the bla and ompA mRNA most of the cleavage sites which were identified map in the 5' non-coding region. The cleavages of the ompA transcript have been previously suggested to regulate the growth rate dependent stability of this mRNA. Thus we propose that the identified endoribonucleolytic activity may be involved in the degradation of mRNA. Analysis of mutants revealed that the cleavages are mediated by endonucleases which do not seem to be identical to RNase III, RNase E or RNase P.
    The EMBO Journal 08/1988; 7(7):2269-75. · 10.75 Impact Factor
  • O. Melefors, U. Lundberg, A. V. Gabain

Publication Stats

507 Citations
86.48 Total Impact Points

Institutions

  • 2008–2013
    • Intercell
      Wien, Vienna, Austria
  • 2012
    • IST Austria
      Klosterneuberg, Lower Austria, Austria
  • 2011
    • Campus Vienna Biocenter (CVBC)
      Wien, Vienna, Austria
  • 1999
    • University of Vienna
      Wien, Vienna, Austria
  • 1990–1993
    • Karolinska Institutet
      • Department of Microbiology, Tumor and Cell Biology (MTC)
      Solna, Stockholm, Sweden
  • 1988
    • Universität Basel
      Bâle, Basel-City, Switzerland