Search > Results

You searched for: EV140050 (EV-TRACK ID)

Showing 1 - 1 of 1

Experiment number
  • If needed, multiple experiments were identified in a single publication based on differing sample types, isolation protocols and/or vesicle types of interest.
Species
  • Species of origin of the EVs.
Isolation protocol
  • Gives a short, non-chronological overview of the different steps of the isolation protocol.
    • dUC = differential ultracentrifugation
    • DG = density gradient
    • UF = ultrafiltration
    • SEC = size-exclusion chromatography
Details EV-TRACK ID Experiment nr. Species Sample type Isolation protocol First author Year EV-METRIC
EV140050 1/1 Streptococcus pneumoniae Bacteria 0.2 µm filter
dUC
Iodixanol-DG (valid.)
SEC
Olaya-Abril A 2014 56%

Study summary

Full title
All authors
Olaya-Abril A, Prados-Rosales R, McConnell MJ, Martín-Peña R, González-Reyes JA, Jiménez-Munguía I, Gómez-Gascón L, Fernández J, Luque-García JL, García-Lidón C, Estévez H, Pachón J, Obando I, Casadevall A, Pirofski LA, Rodríguez-Ortega MJ
Journal
J Proteomics
Abstract
Extracellular vesicles are produced by many pathogenic microorganisms and have varied functions that (show more...)Extracellular vesicles are produced by many pathogenic microorganisms and have varied functions that include secretion and release of microbial factors, which contribute to virulence. Very little is known about vesicle production by Gram-positive bacteria, as well as their biogenesis and release mechanisms. In this work, we demonstrate the active production of vesicles by Streptococcus pneumoniae from the plasma membrane, rather than being a product from cell lysis. We biochemically characterized them by proteomics and fatty acid analysis, showing that these vesicles and the plasma membrane resemble in essential aspects, but have some differences: vesicles are more enriched in lipoproteins and short-chain fatty acids. We also demonstrate that these vesicles act as carriers of surface proteins and virulence factors. They are also highly immunoreactive against human sera and induce immune responses that protect against infection. Overall, this work provides insights into the biology of this important Gram-positive human pathogen and the role of extracellular vesicles in clinical applications.BIOLOGICAL SIGNIFICANCE: Pneumococcus is one of the leading causes of bacterial pneumonia worldwide in children and the elderly, being responsible for high morbidity and mortality rates in developing countries. The augment of pneumococcal disease in developed countries has raised major public health concern, since the difficulties to treat these infections due to increasing antibiotic resistance. Vaccination is still the best way to combat pneumococcal infections. One of the mechanisms that bacterial pathogens use to combat the defense responses of invaded hosts is the production and release of extracellular vesicles derived from the outer surface. Little is known about this phenomenon in Gram-positives. We show that pneumococcus produces membrane-derived vesicles particularly enriched in lipoproteins. We also show the utility of pneumococcal vesicles as a new type of vaccine, as they induce protection in immunized mice against infection with a virulent strain. This work will contribute to understand the role of these structures in important biological processes such as host-pathogen interactions and prevention of human disease. (hide)
EV-METRIC
56% (92nd percentile of all experiments on the same sample type)
 Reported
 Not reported
 Not applicable
EV-enriched proteins
Protein analysis: analysis of three or more EV-enriched proteins
non EV-enriched protein
Protein analysis: assessment of a non-EV-enriched protein
qualitative and quantitative analysis
Particle analysis: implementation of both qualitative and quantitative methods
electron microscopy images
Particle analysis: inclusion of a widefield and close-up electron microscopy image
density gradient
Isolation method: density gradient, at least as validation of results attributed to EVs
EV density
Isolation method: reporting of obtained EV density
ultracentrifugation specifics
Isolation method: reporting of g-forces, duration and rotor type of ultracentrifugation steps
antibody specifics
Protein analysis: antibody clone/reference number and dilution
lysate preparation
Protein analysis: lysis buffer composition
Study data
Sample type
Bacteria
Focus vesicles
extracellular vesicles
Isolation protocol
Isolation protocol
  • Gives a short, non-chronological overview of the
    different steps of the isolation protocol.
    • dUC = differential ultracentrifugation
    • DG = density gradient
    • UF = ultrafiltration
    • SEC = size-exclusion chromatography
0.2 µm filter + dUC + Iodixanol-DG (valid.) + SEC
Protein markers
EV: "MalX/ Pneumococcal surface protein A"
non-EV: Pneumolysin
Proteomics
yes
TEM measurements
20-75
Show all info
Study aim
Function
Sample
Species
Streptococcus pneumoniae
Sample Type
Bacteria
Isolation Method
Differential ultracentrifugation
dUC: centrifugation steps
Between 100,000 g and 150,000 g
Pelleting: time(min)
90
Density gradient
Only used for validation of main results
1
Density medium
Iodixanol
Lowest density fraction
5
Highest density fraction
35
Orientation
Bottom-up
Speed (g)
100000
Filtration steps
0.22µm or 0.2µm
Characterization: Protein analysis
Western Blot
Detected EV-associated proteins
"MalX/ Pneumococcal surface protein A"
Detected contaminants
Pneumolysin
ELISA
Detected EV-associated proteins
"MalX/ Pneumococcal surface protein A"
Fluorescent NTA
Characterization: Particle analysis
EM
EM-type
transmission EM/ immune EM/ scanning EM
1 - 1 of 1