scholarly journals Native Outer Membrane Proteins Protect Mice against Pulmonary Challenge with Virulent Type A Francisella tularensis

2008 ◽  
Vol 76 (8) ◽  
pp. 3664-3671 ◽  
Author(s):  
Jason F. Huntley ◽  
Patrick G. Conley ◽  
David A. Rasko ◽  
Kayla E. Hagman ◽  
Michael A. Apicella ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Francisella Tularensis ◽  
Outer Membrane Proteins ◽  
Interleukin 2 ◽  
Immunoglobulin A ◽  
Type A ◽  
Necrosis Factor Alpha ◽  
Live Attenuated Vaccine ◽  
Virulent Type

ABSTRACT Francisella tularensis is a gram-negative intracellular bacterium and the causative agent of the zoonotic disease tularemia. F. tularensis is a category A select agent and thus a potential agent of bioterrorism. Whereas an F. tularensis live, attenuated vaccine strain (LVS) is the basis of an investigational vaccine, this vaccine is not licensed for human use because of efficacy and safety concerns. In the present study, we immunized mice with isolated native outer membrane proteins (OMPs), ethanol-inactivated LVS (iLVS), or purified LVS lipopolysaccharide (LPS) and assessed the ability of each vaccine preparation to protect mice against pulmonary challenge with the virulent type A F. tularensis strain SchuS4. Antibody isotyping indicated that both Th1 and Th2 antibody responses were generated in mice after immunization with OMPs or iLVS, whereas LPS immunization resulted in only immunoglobulin A production. In survival studies, OMP immunization provided the greatest level of protection (50% survival at 20 days after infection with SchuS4), and there were associated 3-log reductions in the spleen and liver bacterial burdens (compared to nonvaccinated mice). Cytokine quantitation for the sera of SchuS4-challenged mice indicated that OMP and iLVS immunizations induced high levels of tumor necrosis factor alpha and interleukin-2 (IL-2) production, whereas only OMP immunization induced high levels of IL-10 production. By comparison, high levels of proinflammatory cytokines, including RANTES, granulocyte colony-stimulating factor, IL-6, IL-1α, IL-12p40, and KC, in nonvaccinated mice indicated that these cytokines may facilitate disease progression. Taken together, the results of this study demonstrate the potential utility of an OMP subunit (acellular) vaccine for protecting mammals against type A F. tularensis.

scholarly journals Current status of meningococcal group B vaccine candidates: capsular or noncapsular?

1994 ◽  
Vol 7 (4) ◽  
pp. 559-575 ◽  
Author(s):  
J Diaz Romero ◽  
I M Outschoorn
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Capsular Polysaccharide ◽  
Outer Membrane Proteins ◽  
Immunoglobulin A ◽  
Current Status ◽  
Short Term ◽  
Meningococcal Group ◽  
Life Threatening ◽  
Group B

Meningococcal meningitis is a severe, life-threatening infection for which no adequate vaccine exists. Current vaccines, based on the group-specific capsular polysaccharides, provide short-term protection in adults against serogroups A and C but are ineffective in infants and do not induce protection against group B strains, the predominant cause of infection in western countries, because the purified serogroup B polysaccharide fails to elicit human bactericidal antibodies. Because of the poor immunogenicity of group B capsular polysaccharide, different noncapsular antigens have been considered for inclusion in a vaccine against this serogroup: outer membrane proteins, lipooligosaccharides, iron-regulated proteins, Lip, pili, CtrA, and the immunoglobulin A proteases. Alternatively, attempts to increase the immunogenicity of the capsular polysaccharide have been made by using noncovalent complexes with outer membrane proteins, chemical modifications, and structural analogs. Here, we review the strategies employed for the development of a vaccine for Neisseria meningitidis serogroup B; the difficulties associated with the different approaches are discussed.

scholarly journals SalivaryAntibodies Directed against Outer Membrane Proteins ofMoraxella catarrhalis in HealthyAdults

2003 ◽  
Vol 71 (12) ◽  
pp. 6793-6798 ◽  
Author(s):  
Patricia Stutzmann Meier ◽  
Nadja Heiniger ◽  
Rolf Troller ◽  
Christoph Aebi
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Immunoglobulin A ◽  
Immunoblot Analysis ◽  
Human Saliva ◽  
Mucosal Immune Response ◽  
Binding Activity ◽  
Human Respiratory Tract ◽  
Iga Response

ABSTRACT Moraxella catarrhalis is a major mucosal pathogen of the human respiratory tract, but the mucosal immune response directed against surface components of this organism has not been characterized in detail. The aim of this study was to investigate the salivary immunoglobulin A (IgA) response toward outer membrane proteins (OMP) of M. catarrhalis in healthy adults, the group of individuals least likely to be colonized and thus most likely to display mucosal immunity. Unstimulated saliva samples collected from 14 healthy adult volunteers were subjected to IgA immunoblot analysis with OMP preparations of M. catarrhalis strain O35E. Immunoblot analysis revealed a consistent pattern of IgA reactivity, with the appearance of five major bands located at >250, 200, 120, 80, and 60 kDa. Eleven (79%) of 14 saliva samples elicited reactivity to all five bands. Immunoblot analysis with a set of isogenic knockout mutants lacking the expression of individual OMP was used to determine the identities of OMP giving rise to IgA bands. Human saliva was shown consistently to exhibit IgA-binding activity for oligomeric UspA2 (>250 kDa), hemagglutinin (200 kDa), monomeric UspA1 (120 kDa), transferrin-binding protein B (TbpB), monomeric UspA2, CopB, and presumably OMP CD. TbpB, oligomeric UspA2, and CopB formed a cluster of bands at about 80 kDa. These data indicate that the human salivary IgA response is directed consistently against a small number of major OMP, some of which are presently considered vaccine candidates. The functional properties of these mucosal antibodies remain to be elucidated.

scholarly journals Population Structure of Francisella tularensis

2006 ◽  
Vol 188 (14) ◽  
pp. 5319-5324 ◽  
Author(s):  
Ulrich Nübel ◽  
Rolf Reissbrodt ◽  
Annette Weller ◽  
Roland Grunow ◽  
Mustafa Porsch-Özcürümez ◽  
...  
Keyword(s):  
Population Structure ◽  
Membrane Proteins ◽  
Outer Membrane ◽  
Francisella Tularensis ◽  
Genetic Recombination ◽  
Outer Membrane Proteins ◽  
Housekeeping Genes ◽  
Gene Trees ◽  
Phylogenetic Clustering ◽  
Genes Encoding

ABSTRACT We have sequenced fragments of five metabolic housekeeping genes and two genes encoding outer membrane proteins from 81 isolates of Francisella tularensis, representing all four subspecies. Phylogenetic clustering of gene sequences from F. tularensis subsp. tularensis and F. tularensis subsp. holarctica aligned well with subspecies affiliations. In contrast, F. tularensis subsp. novicida and F. tularensis subsp. mediasiatica were indicated to be phylogenetically incoherent taxa. Incongruent gene trees and mosaic structures of housekeeping genes provided evidence for genetic recombination in F. tularensis.

scholarly journals Characterization of Francisella tularensis Outer Membrane Proteins

2006 ◽  
Vol 189 (2) ◽  
pp. 561-574 ◽  
Author(s):  
Jason F. Huntley ◽  
Patrick G. Conley ◽  
Kayla E. Hagman ◽  
Michael V. Norgard
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Francisella Tularensis ◽  
Direct Method ◽  
Outer Membrane Proteins ◽  
Sodium Dodecyl ◽  
Inner Membrane ◽  
Gram Negative ◽  
Schu S4

ABSTRACT Francisella tularensis is a gram-negative coccobacillus that is capable of causing severe, fatal disease in a number of mammalian species, including humans. Little is known about the proteins that are surface exposed on the outer membrane (OM) of F. tularensis, yet identification of such proteins is potentially fundamental to understanding the initial infection process, intracellular survival, virulence, immune evasion and, ultimately, vaccine development. To facilitate the identification of putative F. tularensis outer membrane proteins (OMPs), the genomes of both the type A strain (Schu S4) and type B strain (LVS) were subjected to six bioinformatic analyses for OMP signatures. Compilation of the bioinformatic predictions highlighted 16 putative OMPs, which were cloned and expressed for the generation of polyclonal antisera. Total membranes were extracted from both Schu S4 and LVS by spheroplasting and osmotic lysis, followed by sucrose density gradient centrifugation, which separated OMs from cytoplasmic (inner) membrane and other cellular compartments. Validation of OM separation and enrichment was confirmed by probing sucrose gradient fractions with antibodies to putative OMPs and inner membrane proteins. F. tularensis OMs typically migrated in sucrose gradients between densities of 1.17 and 1.20 g/ml, which differed from densities typically observed for other gram-negative bacteria (1.21 to 1.24 g/ml). Finally, the identities of immunogenic proteins were determined by separation on two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometric analysis. This is the first report of a direct method for F. tularensis OM isolation that, in combination with computational predictions, offers a more comprehensive approach for the characterization of F. tularensis OMPs.

scholarly journals BvrR/BvrS-Controlled Outer Membrane Proteins Omp3a and Omp3b Are Not Essential for Brucella abortus Virulence

2007 ◽  
Vol 75 (10) ◽  
pp. 4867-4874 ◽  
Author(s):  
Lorea Manterola ◽  
Caterina Guzmán-Verri ◽  
Esteban Chaves-Olarte ◽  
Elías Barquero-Calvo ◽  
María-Jesús de Miguel ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Brucella Abortus ◽  
Outer Membrane Proteins ◽  
Regulatory System ◽  
Cell Permeability ◽  
Human Neutrophils ◽  
Necrosis Factor Alpha ◽  
Murine Macrophages

ABSTRACT The Brucella abortus two-component regulatory system BvrR/BvrS controls the expression of outer membrane proteins (Omp) Omp3a (Omp25) and Omp3b (Omp22). Disruption of bvrS or bvrR generates avirulent mutants with altered cell permeability, higher sensitivity to microbicidal peptides, and complement. Consequently, the role of Omp3a and Omp3b in virulence was examined. Similar to bvrS or bvrR mutants, omp3a and omp3b mutants displayed increased attachment to cells, indicating surface alterations. However, they showed unaltered permeability; normal expression of Omp10, Omp16, Omp19, Omp2b, and Omp1; native hapten polysaccharide; and lipopolysaccharide and were resistant to complement and polymyxin B at ranges similar to those of the wild-type (WT) counterpart. Likewise, omp3a and omp3b mutants were able to replicate in murine macrophages and in HeLa cells, were resistant to the killing action of human neutrophils, and persisted in mice, like the WT strain. Murine macrophages infected with the omp3a mutant generated slightly higher levels of tumor necrosis factor alpha than the WT, whereas the bvrS mutant induced lower levels of this cytokine. Since the absence of Omp3a or Omp3b does not result in attenuation, it can be concluded that BvrR/BvrS influences additional Brucella properties involved in virulence. Our results are discussed in the light of previous works suggesting that disruption of omp3a generates attenuated Brucella strains, and we speculate on the role of group 3 Omps.

scholarly journals Characterization of Inner and Outer Membrane Proteins fromFrancisella tularensisStrains LVS and Schu S4 and Identification of Potential Subunit Vaccine Candidates

mBio ◽  
2017 ◽  
Vol 8 (5) ◽  
Author(s):  
Deborah M. B. Post ◽  
Bram Slütter ◽  
Birgit Schilling ◽  
Aroon T. Chande ◽  
Jed A. Rasmussen ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Francisella Tularensis ◽  
Outer Membrane Proteins ◽  
The United States ◽  
Significant Protection ◽  
Infectious Dose ◽  
Spectrometric Data ◽  
Polycytidylic Acid ◽  
Schu S4

ABSTRACTFrancisella tularensisis the causative agent of tularemia and a potential bioterrorism agent. In the present study, we isolated, identified, and quantified the proteins present in the membranes of the virulent type A strain, Schu S4, and the attenuated type B strain, LVS (live vaccine strain). Spectral counting of mass spectrometric data showed enrichment for membrane proteins in both strains. Mice vaccinated with whole LVS membranes encapsulated in poly (lactic-co-glycolic acid) (PLGA) nanoparticles containing the adjuvant polyinosinic-polycytidylic acid [poly(I·C)] showed significant protection against a challenge with LVS compared to the results seen with naive mice or mice vaccinated with either membranes or poly(I·C) alone. The PLGA-encapsulated Schu S4 membranes with poly(I·C) alone did not significantly protect mice from a lethal intraperitoneal challenge with Schu S4; however, this vaccination strategy provided protection from LVS challenge. Mice that received the encapsulated Schu S4 membranes followed by a booster of LVS bacteria showed significant protection with respect to a lethal Schu S4 challenge compared to control mice. Western blot analyses of the sera from the Schu S4-vaccinated mice that received an LVS booster showed four immunoreactive bands. One of these bands from the corresponding one-dimensional (1D) SDS-PAGE experiment represented capsule. The remaining bands were excised, digested with trypsin, and analyzed using mass spectrometry. The most abundant proteins present in these immunoreactive samples were an outer membrane OmpA-like protein, FopA; the type IV pilus fiber building block protein; a hypothetical membrane protein; and lipoproteins LpnA and Lpp3. These proteins should serve as potential targets for future recombinant protein vaccination studies.IMPORTANCEThe low infectious dose, the high potential mortality/morbidity rates, and the ability to be disseminated as an aerosol makeFrancisella tularensisa potential agent for bioterrorism. These characteristics led the Centers for Disease Control (CDC) to classifyF. tularensisas a Tier 1 pathogen. Currently, there is no vaccine approved for general use in the United States.

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