scholarly journals IMMUNOCHEMICAL STUDY OF RECEPTION OF PLAGUE BACTERIOPHAGE POKROVSKY

2016 ◽  
pp. 16-21
Author(s):  
A. A. Byvalov ◽  
L. G. Dudina ◽  
S. G. Litvinets ◽  
E. A. Martinson
Keyword(s):  
Monoclonal Antibodies ◽  
Yersinia Pestis ◽  
Outer Membrane ◽  
Competitive Inhibition ◽  
Bacterial Cells ◽  
Immunochemical Study ◽  
Antigenic Epitopes

Aim. Study of mechanism of reception of plague bacteriophage Pokrovsky to cells of Yersinia pestis using a panel of monoclonal antibodies. Materials and methods. Using a method of competitive inhibition, the ability of monoclonal antibodies against antigenic epitopes of outer membrane of Yersinia genus bacteria to inhibit adhesion of the studied bacteriophage to cells of Y. pestis EV strain, was evaluated. Results. A key role of structure of carbohydrate nature in reception of Pokrovsky bacteriophage was confirmed. Among 5 lines of monoclonal antibodies against protein epitopes 2 were established to cause significant inactivation of bacteriophage adhesion to bacterial cells. Conclusion. An assumption is proposed regarding participation of a structure of polypeptide nature in reception of Pokrovsky bacteriophage by cells of plague microbe.

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 Fc-Dependent Polyclonal Antibodies and Antibodies to Outer Membrane Proteins A and B, but Not to Lipopolysaccharide, Protect SCID Mice against Fatal Rickettsia conorii Infection

2004 ◽  
Vol 72 (4) ◽  
pp. 2222-2228 ◽  
Author(s):  
Hui-Min Feng ◽  
Ted Whitworth ◽  
Juan P. Olano ◽  
Vsevolod L. Popov ◽  
David H. Walker
Keyword(s):  
Monoclonal Antibodies ◽  
Outer Membrane ◽  
Spotted Fever ◽  
Outer Membrane Proteins ◽  
Severe Combined Immunodeficiency ◽  
Scid Mice ◽  
Rickettsia Conorii ◽  
Antibody Treatment ◽  
Fab Fragments

ABSTRACT An emphasis on cellular immunity against Rickettsia has led to neglect of analysis of the role of antibody. The availability of an excellent mouse model of spotted fever rickettsiosis enabled investigation of a potential role of antibody in immunity to Rickettsia conorii. C3H severe combined immunodeficiency (SCID) mice were passively transfused with monoclonal antibodies against rickettsial outer membrane protein A (OmpA), OmpB, or lipopolysaccharide (LPS), polyclonal anti-R. conorii serum, Fab fragments of polyclonal antiserum, or no antibodies and then challenged 48 h later with 10 50% lethal doses (LD50) of R. conorii. All mice that received monoclonal antibodies against OmpA and two of four mice that received monoclonal antibodies against OmpB or polyclonal antisera were completely protected, but the recipients of anti-LPS antibodies or the Fab fragments were not protected. Polyclonal antibody treatment of C3H SCID mice that had been infected with 10 LD50 of R. conorii 4 or 5 days earlier prolonged the life of the infected mice from 10.4 to 22.5 days and resulted in decreased levels of infectious rickettsiae in the spleen and liver 24 and 48 h later. Treatment with protective antibodies resulted in the development of large aggregates of R. conorii antigens in splenic macrophages and intraphagolysosomal rickettsial death and digestion. The kinetics of development of antibodies to R. conorii determined by immunoblotting revealed antibodies to LPS on day 6 and antibodies to OmpA and OmpB on day 12, when recovery from the infection had already occurred. Antibodies to particular epitopes of OmpA and OmpB may protect against reinfection, but they may not play a key role in immunity against primary infection. Antibodies might be useful for treating infections with antibiotic-resistant organisms, and some B-cell epitopes should be included in a subunit vaccine.

Monoclonal Antibodies to Sweet Taste Proteins. I. Analysis of Antigenic Epitopes on Thaumatin by Competitive Inhibition Assays

Hybridoma ◽  
1991 ◽  
Vol 10 (4) ◽  
pp. 459-466 ◽  
Author(s):  
CHITRA MANDAL ◽  
FRANCINE SHIRLEY ◽  
JERRY M. ANCHIN ◽  
CHHABINATH MANDAL ◽  
D. SCOTT LINTHICUM
Keyword(s):  
Monoclonal Antibodies ◽  
Competitive Inhibition ◽  
Sweet Taste ◽  
Antigenic Epitopes

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.

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

Plasminogen Activation In Vivo upon Intravenous Infusion of DDAVP

1992 ◽  
Vol 67 (01) ◽  
pp. 111-116 ◽  
Author(s):  
Marcel Levi ◽  
Jan Paul de Boer ◽  
Dorina Roem ◽  
Jan Wouter ten Cate ◽  
C Erik Hack
Keyword(s):  
Monoclonal Antibodies ◽  
Plasminogen Activator ◽  
Plasma Levels ◽  
Fold Increase ◽  
Fibrinolytic System ◽  
Plasminogen Activation ◽  
Plasminogen Activator Activity ◽  
Insight Into

SummaryInfusion of desamino-d-arginine vasopressin (DDAVP) results in an increase in plasma plasminogen activator activity. Whether this increase results in the generation of plasmin in vivo has never been established.A novel sensitive radioimmunoassay (RIA) for the measurement of the complex between plasmin and its main inhibitor α2 antiplasmin (PAP complex) was developed using monoclonal antibodies preferentially reacting with complexed and inactivated α2-antiplasmin and monoclonal antibodies against plasmin. The assay was validated in healthy volunteers and in patients with an activated fibrinolytic system.Infusion of DDAVP in a randomized placebo controlled crossover study resulted in all volunteers in a 6.6-fold increase in PAP complex, which was maximal between 15 and 30 min after the start of the infusion. Hereafter, plasma levels of PAP complex decreased with an apparent half-life of disappearance of about 120 min. Infusion of DDAVP did not induce generation of thrombin, as measured by plasma levels of prothrombin fragment F1+2 and thrombin-antithrombin III (TAT) complex.We conclude that the increase in plasminogen activator activity upon the infusion of DDAVP results in the in vivo generation of plasmin, in the absence of coagulation activation. Studying the DDAVP induced increase in PAP complex of patients with thromboembolic disease and a defective plasminogen activator response upon DDAVP may provide more insight into the role of the fibrinolytic system in the pathogenesis of thrombosis.

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