Immuno-electron microscopy of surface antigens of Bordetella pertussis

1988 ◽  
Vol 46 ◽  
pp. 314-315
Author(s):  
M. E. Bisher ◽  
M. J. Brennan ◽  
Z. M. Li ◽  
A. C. Steven
Keyword(s):  
Electron Microscopy ◽  
Bordetella Pertussis ◽  
Molecular Level ◽  
Whooping Cough ◽  
Surface Antigens ◽  
Negative Bacterium ◽  
Convenient Means ◽  
Immuno Electron Microscopy ◽  
Serotype 1 ◽  
Different Strains

Bordetella pertussis is the Gram-negative bacterium responsible for whooping-cough. To develop a better understanding of the interactions between B. pertussis and the cells of colonized tissues, as well as for purposes of vaccine design, much effort has been devoted to characterizing the antigenic molecules exposed at its outer surface. A set of six U.S. Reference Factor Antisera raised by Eldering recognize agglutinogens that are specific to B. pertussis. Since each strain exhibits a particular subset of these antigens, the antisera provide a convenient means of classifying different strains of this bacterium. Several of these antigens have been identified at the molecular level. Serotype 1 agglutinogen is associated with a lipo-oligosaccharide, and those of serotypes 2 and 6 are fimbriae of two morphologically similar but antigenically distinct kinds. Recently, it has been demonstrated serotype 3 antiserum recognizes a 69kDa protein. To characterize the distribution of this antigen in and around B. pertussis cells, we have performed immuno-gold electron microscopy, using monoclonal antibodies raised against the 69kDa protein.

scholarly journals Molecular Basis for Bordetella pertussis Interference with Complement, Coagulation, Fibrinolytic, and Contact Activation Systems: the Cryo-EM Structure of the Vag8-C1 Inhibitor Complex

mBio ◽  
2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Arun Dhillon ◽  
Justin C. Deme ◽  
Emily Furlong ◽  
Dorina Roem ◽  
Ilse Jongerius ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bordetella Pertussis ◽  
Whooping Cough ◽  
C1 Inhibitor ◽  
Contact Activation ◽  
Content Type ◽  
Reactive Center Loop ◽  
Cryo Electron Microscopy ◽  
Reactive Center ◽  
Coagulation And Fibrinolysis

ABSTRACT Complement, contact activation, coagulation, and fibrinolysis are serum protein cascades that need strict regulation to maintain human health. Serum glycoprotein, a C1 inhibitor (C1-INH), is a key regulator (inhibitor) of serine proteases of all the above-mentioned pathways. Recently, an autotransporter protein, virulence-associated gene 8 (Vag8), produced by the whooping cough pathogen, Bordetella pertussis, was shown to bind to C1-INH and interfere with its function. Here, we present the structure of the Vag8–C1-INH complex determined using cryo-electron microscopy at a 3.6-Å resolution. The structure shows a unique mechanism of C1-INH inhibition not employed by other pathogens, where Vag8 sequesters the reactive center loop of C1-INH, preventing its interaction with the target proteases. IMPORTANCE The structure of a 10-kDa protein complex is one of the smallest to be determined using cryo-electron microscopy at high resolution. The structure reveals that C1-INH is sequestered in an inactivated state by burial of the reactive center loop in Vag8. By so doing, the bacterium is able to simultaneously perturb the many pathways regulated by C1-INH. Virulence mechanisms such as the one described here assume more importance given the emerging evidence about dysregulation of contact activation, coagulation, and fibrinolysis leading to COVID-19 pneumonia.

Surface-exposed antibody-accessible outer membrane proteins of Bordetella pertussis

1991 ◽  
Vol 37 (8) ◽  
pp. 590-593 ◽  
Author(s):  
Hosmin Anwar
Keyword(s):  
Immune Response ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Key Words ◽  
Outer Membrane ◽  
Bordetella Pertussis ◽  
Outer Membrane Protein ◽  
Whooping Cough ◽  
Outer Membrane Proteins ◽  
Surface Antigens

The convalescent sera from a patient recovered form whooping cough were used to identify the surface-exposed antibody-accessible outer membrane proteins (OMPs) of Bordetella pertussis. The results indicated that the 69 000 OMP, the 40 000 porin, agglutinogens 2 and 3, and a number of presently unknown OMPs were exposed on the surface. The importance of these surface-exposed antigens in the protection against whooping cough is discussed. Key words: Bordetella pertussis, whooping cough, immune response, surface antigens, outer membrane protein.

Structural organization of escherichia coli ribosomes as determined by immuno electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 166-167 ◽  
Author(s):  
G. Stöffler ◽  
R.W. Bald ◽  
J. Dieckhoff ◽  
H. Eckhard ◽  
R. Lührmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Ribosomal Subunit ◽  
Spatial Arrangement ◽  
Small Subunit ◽  
Antibody Binding ◽  
Immuno Electron Microscopy

A central step towards an understanding of the structure and function of the Escherichia coli ribosome, a large multicomponent assembly, is the elucidation of the spatial arrangement of its 54 proteins and its three rRNA molecules. The structural organization of ribosomal components has been investigated by a number of experimental approaches. Specific antibodies directed against each of the 54 ribosomal proteins of Escherichia coli have been performed to examine antibody-subunit complexes by electron microscopy. The position of the bound antibody, specific for a particular protein, can be determined; it indicates the location of the corresponding protein on the ribosomal surface.The three-dimensional distribution of each of the 21 small subunit proteins on the ribosomal surface has been determined by immuno electron microscopy: the 21 proteins have been found exposed with altogether 43 antibody binding sites. Each one of 12 proteins showed antibody binding at remote positions on the subunit surface, indicating highly extended conformations of the proteins concerned within the 30S ribosomal subunit; the remaining proteins are, however, not necessarily globular in shape (Fig. 1).

A web-like network of type vi collagen in human skin is revealed by immuno-electron microscopy

1988 ◽  
Vol 46 ◽  
pp. 382-383
Author(s):  
Douglas R. Keene ◽  
Robert W. Glanville ◽  
Eva Engvall
Keyword(s):  
Electron Microscopy ◽  
Monoclonal Antibody ◽  
Human Skin ◽  
Basement Membranes ◽  
Primary Antibody ◽  
Fat Cells ◽  
Secondary Antibody ◽  
Type Vi Collagen ◽  
Dermal Matrix ◽  
Immuno Electron Microscopy

A mouse monoclonal antibody (5C6) prepared against human type VI collagen (1) has been used in this study to immunolocalize type VI collagen in human skin. The enbloc method used involves exposing whole tissue pieces to primary antibody and 5 nm gold conjugated secondary antibody before fixation, and has been described in detail elsewhere (2).Biopsies were taken from individuals ranging in age from neonate to 65 years old. By immuno-electron microscopy, type VI collagen is found to be distributed as a fine branching network closely associated with (but not attached to) banded collagen fibrils containing types I and III collagen (Fig. 1). It appears to enwrap fibers, to weave between individual fibrils within a fiber, and to span the distance separating fibers, creating a “web-like network” which entraps fibers within deep papillary and reticular dermal layers (Fig. 2). Relative to that in the dermal matrix, the concentration of type VI collagen is higher around endothelial basement membranes limiting the outer boundaries of nerves, capillaries, and fat cells (Fig. 3).

The Current Situation in Chemical Stabilization of Biological Materials

1972 ◽  
Vol 30 ◽  
pp. 132-133
Author(s):  
John H. Luft
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Osmium Tetroxide ◽  
Molecular Level ◽  
Cross Linking ◽  
Chemical Stabilization ◽  
Specimen Preparation ◽  
Sufficient Condition ◽  
Radio Telescopes

With information processing devices such as radio telescopes, microscopes or hi-fi systems, the quality of the output often is limited by distortion or noise introduced at the input stage of the device. This analogy can be extended usefully to specimen preparation for the electron microscope; fixation, which initiates the processing sequence, is the single most important step and, unfortunately, is the least well understood. Although there is an abundance of fixation mixtures recommended in the light microscopy literature, osmium tetroxide and glutaraldehyde are favored for electron microscopy. These fixatives react vigorously with proteins at the molecular level. There is clear evidence for the cross-linking of proteins both by osmium tetroxide and glutaraldehyde and cross-linking may be a necessary if not sufficient condition to define fixatives as a class.

scholarly journals Morphological Alterations and Increased S100B Expression in Epidermal Langerhans Cells Detected in Skin from Patients with Progressive Vitiligo

Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 579
Author(s):  
Fei Yang ◽  
Lingli Yang ◽  
Lanting Teng ◽  
Huimin Zhang ◽  
Ichiro Katayama
Keyword(s):  
Electron Microscopy ◽  
Langerhans Cells ◽  
Critical Role ◽  
Light And Electron Microscopy ◽  
Morphological Alterations ◽  
Birbeck Granules ◽  
Immuno Electron Microscopy ◽  
Skin Biopsies ◽  
Epidermal Langerhans Cells

The role of Langerhans cells (LCs) in vitiligo pathogenesis remains unclear, with published studies reporting contradictory results regarding the quantity of LCs and no data on the features of LCs in vitiligo. Here, we aimed to analyze the presence, density, and morphological features of LCs in the epidermis of patients with vitiligo. Skin biopsies were stained for LCs using anti-CD1a/anti-langerin antibodies and analyzed by immunocytochemistry with light and electron microscopy. Compared with healthy controls, we detected significantly increased numbers of epidermal LCs in lesional skin from vitiligo in the progressive state. These LCs exhibited striking morphological alterations, including an elevated number of dendrites, with increased length and more branches than dendrites from controls. Ultrastructure examination via immuno-electron microscopy revealed markedly reduced Birbeck granules (BGs) and shorter BG rods in LCs from progressive vitiligo, with higher expression of langerin. Additionally, expression of S100B, the activity biomarker of vitiligo, was increased in these LCs. This work provides new insight on the cellular composition of LCs in vitiliginous skin, revealing altered morphology and increased LC numbers, with elevated S100B expression. Our data suggest LCs might play a critical role in vitiligo pathogenesis and thus may represent a novel therapeutic target for this disease.

Immuno-electron Microscopy of Hepatitis B Antigen in Liver

1972 ◽  
Vol 140 (4) ◽  
pp. 1334-1339 ◽  
Author(s):  
M. A. Gerber ◽  
F. Schaffner ◽  
F. Paronetto
Keyword(s):  
Electron Microscopy ◽  
Hepatitis B ◽  
Immuno Electron Microscopy ◽  
Hepatitis B Antigen

scholarly journals Diphtheria-tetanus-pertussis vaccine combined with Bordetella parapertussis vaccine

1962 ◽  
Vol 60 (3) ◽  
pp. 289-293 ◽  
Author(s):  
Neda Köhler-Kubelka
Keyword(s):  
Clinical Examination ◽  
Pertussis Vaccine ◽  
Bordetella Pertussis ◽  
Whooping Cough ◽  
Production Test ◽  
Post Vaccination ◽  
Bordetella Parapertussis ◽  
Cross Reactions ◽  
Combined Vaccine

Investigations carried out to ascertain the ability of various strains of Bordetella pertussis and B. parapertussis to produce agglutinins have shown that the agglutinin response is considerably greater with B. parapertussis.Children inoculated with a combined vaccine in which the parapertussis element contained B. parapertussis in only one-twelfth of the concentration of B. pertussis in the pertussis element showed agglutinins in their sera in titres well above 1:300 for both organisms. There were no cross-reactions and the serological responses were specific throughout. The vaccine used was the standard diphtheria-tetanus-pertussis (DTP) prophylactic to which had been added a vaccine prepared from recently isolated strains of B. parapertussis.Agglutinin titres of both whooping cough components with the combined vaccine were somewhat lower in mice than was the case when monovalent vaccines were used, but they were considered to be satisfactory.It is suggested that the agglutination production test in mice could be used for the assessment of protective power of B. parapertussis vaccines against infection.I wish to thank Dr Ikić, director of the Institute of Immunology, Zagreb, who enabled me to perform all these examinations, further to Dr B. Mravunac and Dr Z. Radanov for having carried out vaccination in children and for the clinical examination of post vaccination reactions.

scholarly journals Functional Entry of Baculovirus into Insect and Mammalian Cells Is Dependent on Clathrin-Mediated Endocytosis

2006 ◽  
Vol 80 (17) ◽  
pp. 8830-8833 ◽  
Author(s):  
Gang Long ◽  
Xiaoyu Pan ◽  
Richard Kormelink ◽  
Just M. Vlak
Keyword(s):  
Electron Microscopy ◽  
Mammalian Cells ◽  
Low Ph ◽  
Coated Pits ◽  
Immuno Electron Microscopy ◽  
Endocytosis Pathway ◽  
Ph Dependent ◽  
Budded Virus

ABSTRACT Entry of the budded virus form of baculoviruses into insect and mammalian cells is generally thought to occur through a low-pH-dependent endocytosis pathway, possibly through clathrin-coated pits. This insight is primarily based on (immuno)electron microscopy studies but requires biochemical support to exclude the use of other pathways. Here, we demonstrate using various inhibitors that functional entry of baculoviruses into insect and mammalian cells is primarily dependent on clathrin-mediated endocytosis. Our results further suggest that caveolae are somehow involved in baculovirus entry in mammalian cells. A caveolar endocytosis inhibitor, genistein, enhances baculovirus transduction in these cells considerably.

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