scholarly journals Resistance of Yersinia pestis to Complement-Dependent Killing Is Mediated by the Ail Outer Membrane Protein

2007 ◽  
Vol 76 (2) ◽  
pp. 612-622 ◽  
Author(s):  
Sara Schesser Bartra ◽  
Katie L. Styer ◽  
Deanna M. O'Bryant ◽  
Matthew L. Nilles ◽  
B. Joseph Hinnebusch ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Yersinia Pestis ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Pathogenic Bacteria ◽  
Outer Membrane Proteins ◽  
Mouse Serum ◽  
Bacterial Killing ◽  
High Level

ABSTRACT Yersinia pestis, the causative agent of plague, must survive in blood in order to cause disease and to be transmitted from host to host by fleas. Members of the Ail/Lom family of outer membrane proteins provide protection from complement-dependent killing for a number of pathogenic bacteria. The Y. pestis KIM genome is predicted to encode four Ail/Lom family proteins. Y. pestis mutants specifically deficient in expression of each of these proteins were constructed using lambda Red-mediated recombination. The Ail outer membrane protein was essential for Y. pestis to resist complement-mediated killing at 26 and 37°C. Ail was expressed at high levels at both 26 and 37°C, but not at 6°C. Expression of Ail in Escherichia coli provided protection from the bactericidal activity of complement. High-level expression of the three other Y. pestis Ail/Lom family proteins (the y1682, y2034, and y2446 proteins) provided no protection against complement-mediated bacterial killing. A Y. pestis ail deletion mutant was rapidly killed by sera obtained from all mammals tested except mouse serum. The role of Ail in infection of mice, Caenorhabditis elegans, and fleas was investigated.

scholarly journals Outer Membrane Protein X (Ail) Contributes to Yersinia pestis Virulence in Pneumonic Plague and Its Activity Is Dependent on the Lipopolysaccharide Core Length

2010 ◽  
Vol 78 (12) ◽  
pp. 5233-5243 ◽  
Author(s):  
Anna M. Kolodziejek ◽  
Darren R. Schnider ◽  
Harold N. Rohde ◽  
Andrzej J. Wojtowicz ◽  
Gregory A. Bohach ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Yersinia Pestis ◽  
Outer Membrane ◽  
Rat Model ◽  
Outer Membrane Protein ◽  
Serum Resistance ◽  
Wild Type ◽  
Time To Death ◽  
Protein X

ABSTRACT Yersinia pestis, the causative agent of plague, is one of the most virulent microorganisms known. The outer membrane protein X (OmpX) in Y. pestis KIM is required for efficient bacterial adherence to and internalization by cultured HEp-2 cells and confers resistance to human serum. Here, we tested the contribution of OmpX to disease progression in the fully virulent Y. pestis CO92 strain by engineering a deletion mutant and comparing its ability in mediating pneumonic plague to that of the wild type in two animal models. The deletion of OmpX delayed the time to death up to 48 h in a mouse model and completely attenuated virulence in a rat model of disease. All rats challenged with 1 × 108 CFU of the ompX mutant survived, compared to the 50% lethal dose (LD50) of 1.2 × 103 CFU for the wild-type strain. Because murine serum is not bactericidal for the ompX mutant, the mechanism underlying the delay in time to death in mice was attributed to loss of adhesion/internalization properties but not serum resistance. The rat model, which is most similar to humans, highlighted the critical role of serum resistance in disease. To resolve conflicting evidence for the role of Y. pestis lipopolysaccharide (LPS) and OmpX in serum resistance, ompX was cloned into Escherichia coli D21 and three isogenic derivatives engineered to have progressively truncated LPS core saccharides. OmpX-mediated serum resistance, adhesiveness, and invasiveness, although dependent on LPS core length, displayed these functions in E. coli, independently of other Yersinia proteins and/or LPS. Also, autoaggregation was required for efficient OmpX-mediated adhesiveness and internalization but not serum resistance.

scholarly journals Evaluation of Protective Potential of Yersinia pestis Outer Membrane Protein Antigens as Possible Candidates for a New-Generation Recombinant Plague Vaccine

2012 ◽  
Vol 20 (2) ◽  
pp. 227-238 ◽  
Author(s):  
Tatiana E. Erova ◽  
Jason A. Rosenzweig ◽  
Jian Sha ◽  
Giovanni Suarez ◽  
Johanna C. Sierra ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Yersinia Pestis ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Outer Membrane Proteins ◽  
Spectrometric Analysis ◽  
Protein Antigens ◽  
Pneumonic Plague ◽  
Content Type ◽  
New Generation

ABSTRACTPlague caused byYersinia pestismanifests itself in bubonic, septicemic, and pneumonic forms. Although the U.S. Food and Drug Administration recently approved levofloxacin, there is no approved human vaccine against plague. The capsular antigen F1 and the low-calcium-response V antigen (LcrV) ofY. pestisrepresent excellent vaccine candidates; however, the inability of the immune responses to F1 and LcrV to provide protection againstY. pestisF1−strains or those which harbor variants of LcrV is a significant concern. Here, we show that the passive transfer of hyperimmune sera from rats infected with the plague bacterium and rescued by levofloxacin protected naive animals against pneumonic plague. Furthermore, 10 to 12 protein bands from wild-type (WT)Y. pestisCO92 reacted with the aforementioned hyperimmune sera upon Western blot analysis. Based on mass spectrometric analysis, four of these proteins were identified as attachment invasion locus (Ail/OmpX), plasminogen-activating protease (Pla), outer membrane protein A (OmpA), and F1. The genes encoding these proteins were cloned, and the recombinant proteins purified fromEscherichia colifor immunization purposes before challenging mice and rats with either the F1−mutant or WT CO92 in bubonic and pneumonic plague models. Although antibodies to Ail and OmpA protected mice against bubonic plague when challenged with the F1−CO92 strain, Pla antibodies were protective against pneumonic plague. In the rat model, antibodies to Ail provided protection only against pneumonic plague after WT CO92 challenge. Together, the addition ofY. pestisouter membrane proteins to a new-generation recombinant vaccine could provide protection against a wide variety ofY. pestisstrains.

scholarly journals Salmonella Typhimurium outer membrane protein A (OmpA) renders protection against nitrosative stress by promoting SCV stability in murine macrophage

2021 ◽  
Author(s):  
Atish Roy Chowdhury ◽  
Dipshikha Chakravortty
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Nitrosative Stress ◽  
Outer Membrane Proteins ◽  
Protein A ◽  
Listeriolysin O ◽  
Bacterial Outer Membrane ◽  
Outer Membrane Protein A

AbstractPorins are highly conserved bacterial outer membrane proteins having β barrel structure and are majorly involved in the selective transport of charged molecules across the membrane. Despite having huge contributions in the pathogenesis of many gram-negative bacteria, their role remains elusive in salmonellosis. In this study, we have characterized the pathogenic role of porins majorly found on the outer membrane of Salmonella Typhimurium (such as OmpA, OmpC, OmpD, and OmpF) paying the utmost importance to OmpA. The outer membrane protein A (OmpA) of Salmonella Typhimurium has shown a multifaceted role in our study. We have observed that deletion of ompA from wildtype Salmonella has made it more prone to phagocytosis and weakly proliferative in macrophages. Whereas, in epithelial cells STM ΔompA was found to be invasion deficient and hyper-proliferative. The poor colocalization of STM ΔompA with LAMP-1 confirmed impaired stability of SCV membrane around the intracellular bacteria, which further resulted in the release of the knockout strain to the cytosol of macrophage where it is bombarded with reactive nitrogen intermediates (RNI). The cytosolic localization of STM ΔompA was found to be responsible for the downregulation of SPI-2 encoded virulent factor SpiC which is required for suppressing the activity of iNOS. The reduced recruitment of nitrotyrosine on wildtype Salmonella staying in the cytosol of macrophage by ectopically expressing Listeriolysin O (LLO) strongly proves the pro-bacterial role of OmpA against host nitrosative stress. The time-dependent increase in 405/ 488 ratio of STM ΔompA pQE60-Grx1-roGFP2 exposed to in vitro acidified nitrite suggested RNI dependent redox burst which further answered the reason for its enhanced sensitivity towards nitrosative stress. Our study further demonstrated loss of integrity and enhanced porosity in the bacterial outer membrane in absence of OmpA. The enhanced porosity of the bacterial outer membrane was further attributed to the upregulated expression of larger porins namely ompC, ompD, and ompF. In comparison with STM ΔompA ΔompC and ΔompA ΔompF, the enhanced uptake of nitrite and greater recruitment of nitrotyrosine on intracellular STM ΔompA ΔompD demonstrate the involvement of OmpC and OmpF in the entry of excess nitrite in ompA deficient bacteria.

scholarly journals DsbA Is Required for Stable Expression of Outer Membrane Protein YscC and for Efficient Yop Secretion inYersinia pestis

1999 ◽  
Vol 181 (16) ◽  
pp. 5126-5130 ◽  
Author(s):  
Michael W. Jackson ◽  
Gregory V. Plano
Keyword(s):  
Membrane Protein ◽  
Yersinia Pestis ◽  
Outer Membrane ◽  
Disulfide Bond ◽  
Outer Membrane Protein ◽  
Site Directed Mutagenesis ◽  
Cysteine Residues ◽  
Directed Mutagenesis ◽  
Disulfide Oxidoreductase

ABSTRACT The role of the periplasmic disulfide oxidoreductase DsbA in Yop secretion was investigated in Yersinia pestis. A Y. pestis dsbA mutant secreted reduced amounts of the V antigen and Yops and expressed reduced amounts of the full-sized YscC protein. Site-directed mutagenesis of the four cysteine residues present in the YscC protein resulted in defects similar to those found in thedsbA mutant. These results suggest that YscC contains at least one disulfide bond that is essential for the function of this protein in Yop secretion.

scholarly journals Yersinia outer-membrane protein B (YopB): a tool for identification of Yersinia pestis isolates

2006 ◽  
Vol 55 (4) ◽  
pp. 467-469 ◽  
Author(s):  
Rekha Khushiramani ◽  
Jyoti Shukla ◽  
Urmil Tuteja ◽  
Harsh Vardhan Batra
Keyword(s):  
Membrane Protein ◽  
Yersinia Pestis ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Protein B

Outer Membrane Protein Composition in Disease Isolates of Haemophilus influenzae : Pathogenic and Epidemiological Implications

1980 ◽  
Vol 30 (3) ◽  
pp. 709-717
Author(s):  
Marilyn R. Loeb ◽  
David H. Smith
Keyword(s):  
Membrane Proteins ◽  
Membrane Protein ◽  
Haemophilus Influenzae ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Outer Membrane Proteins ◽  
Protein Composition ◽  
The Other ◽  
Major Protein ◽  
Single Strain

The outer membrane protein composition of 50 disease isolates of Haemophilus influenzae has been determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. All strains, including 28 strains of serotype b , one strain each of serotypes a, c, d, e , and f , and 17 untypable strains, had an outer membrane protein composition typical of gram-negative bacteria, i.e., these membranes contained two to three dozen proteins with four to six proteins accounting for most of their protein content. Variation in the mobility of these major outer membrane proteins from strain to strain was common but not universal; the observed patterns provided useful data and new insight into the epidemiology of type b disease. The basic findings can be summarized as follows: (i) All 50 strains possessed three proteins (one minor and two major) each having identical mobilities. The other proteins, both major and minor, varied in mobility. (ii) All type b strains possessed a fourth (major) protein of identical mobility. (iii) The 28 type b strains, on the basis of the mobility of the six major outer membrane proteins, could be divided into eight subtypes. Of all the other strains examined, both typable and untypable, only the serotype a strain belonged to one of these subtypes. (iv) The untypable strains showed considerable variation in the mobilities of their major outer membrane proteins. Of these 17 strains, 13 had an additional major outer membrane protein not present in encapsulated strains. (v) The outer membrane protein composition of a single strain remained unchanged after many passages on solid media, but varied with the growth phase. (vi) The outer membrane protein composition of isolates obtained from nine patients during an epidemic of type b meningitis varied, indicating that a single strain was not responsible for the epidemic. At least five different strains were responsible for these nine cases. (vii) Identical outer membrane protein compositions were observed in the following: in a type b strain and a mutant of this strain deficient in capsule production, indicating that the level of capsule synthesis is not obviously related to outer membrane protein composition; in type b strains isolated from different anatomic sites of patients acutely ill with meningitis, indicating that the strain associated with bacteremia is the same as that isolated from the cerebrospinal fluid; in type b strains isolated from siblings who contracted meningitis at about the same time, indicating infection with the same strain; and in type b strains isolated from the initial and repeat infection of a single patient, suggesting that reinfection was due to the same strain.

scholarly journals Sequence Polymorphism, Predicted Secondary Structures, and Surface-Exposed Conformational Epitopes of Campylobacter Major Outer Membrane Protein

2000 ◽  
Vol 68 (10) ◽  
pp. 5679-5689 ◽  
Author(s):  
Qijing Zhang ◽  
Jerrel C. Meitzler ◽  
Shouxiong Huang ◽  
Teresa Morishita
Keyword(s):  
Amino Acid ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Outer Membrane Proteins ◽  
Major Outer Membrane Protein ◽  
Amino Acid Sequences ◽  
Variable Regions ◽  
Conserved Sequences ◽  
Conformational Epitopes

ABSTRACT The major outer membrane protein (MOMP), a putative porin and a multifunction surface protein of Campylobacter jejuni, may play an important role in the adaptation of the organism to various host environments. To begin to dissect the biological functions and antigenic features of this protein, the gene (designatedcmp) encoding MOMP was identified and characterized from 22 strains of C. jejuni and one strain of C. coli. It was shown that the single-copy cmp locus encoded a protein with characteristics of bacterial outer membrane proteins. Prediction from deduced amino acid sequences suggested that each MOMP subunit consisted of 18 β-strands connected by short periplasmic turns and long irregular external loops. Alignment of the amino acid sequences of MOMP from different strains indicated that there were seven localized variable regions dispersed among highly conserved sequences. The variable regions were located in the putative external loop structures, while the predicted β-strands were formed by conserved sequences. The sequence homology of cmp appeared to reflect the phylogenetic proximity of C. jejuni strains, since strains with identical cmp sequences had indistinguishable or closely related macrorestriction fragment patterns. Using recombinant MOMP and antibodies recognizing linear or conformational epitopes of the protein, it was demonstrated that the surface-exposed epitopes of MOMP were predominantly conformational in nature. These findings are instrumental in the design of MOMP-based diagnostic tools and vaccines.

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