What do microparticles from blood plasma look like? Their morphology, size and phenotype revealed by cryo-EM and immuno-gold labeling
Event details
| Date | 21.03.2013 |
| Hour | 11:00 › 12:00 |
| Speaker | Prof. Alain Brisson, Université Bordeaux |
| Location | |
| Category | Conferences - Seminars |
Microparticles (MPs), also called extracellular vesicles or microvesicles, are cell membrane
fragments derived from activated or apoptotic cells. MPs attract high interest as potential disease
biomarkers because they contain elements, like surface receptors, specific from their parental cells.
However many basic questions concerning MPs remain unanswered, such as: What do MPs from
blood plasma look like? What is their morphology, their size distribution? Do they all bind Annexin-5
(Anx5)? How are they formed? How many are they?
Our overall aim is to answer these questions, firstly to improve our basic understanding on MPs,
secondly to design diagnosis assays on selected MP sub-populations. Our first objective was to
provide a catalogue of all types of MPs present in plasma from healthy donors, considering this as a
reference for further studies of MPs in various pathological conditions.
We have developed an original approach based on cryo-Transmission Electron Microscopy
(cryo-EM) imaging and receptor-specific gold labeling. Cryo-EM allows revealing the
various types of MPs present in pure platelet free plasma (PFP). Gold nanoparticles
functionalized with various ligands were developed for identifying specific MP subpopulations.
We focused our attention primarily on MPs exposing phosphatidylserine (PS),
MPs derived from platelets and MPs derived from red blood cells, using gold particles
functionalized with Anx5, anti-CD41 and anti-glycophorin antibodies, respectively
fragments derived from activated or apoptotic cells. MPs attract high interest as potential disease
biomarkers because they contain elements, like surface receptors, specific from their parental cells.
However many basic questions concerning MPs remain unanswered, such as: What do MPs from
blood plasma look like? What is their morphology, their size distribution? Do they all bind Annexin-5
(Anx5)? How are they formed? How many are they?
Our overall aim is to answer these questions, firstly to improve our basic understanding on MPs,
secondly to design diagnosis assays on selected MP sub-populations. Our first objective was to
provide a catalogue of all types of MPs present in plasma from healthy donors, considering this as a
reference for further studies of MPs in various pathological conditions.
We have developed an original approach based on cryo-Transmission Electron Microscopy
(cryo-EM) imaging and receptor-specific gold labeling. Cryo-EM allows revealing the
various types of MPs present in pure platelet free plasma (PFP). Gold nanoparticles
functionalized with various ligands were developed for identifying specific MP subpopulations.
We focused our attention primarily on MPs exposing phosphatidylserine (PS),
MPs derived from platelets and MPs derived from red blood cells, using gold particles
functionalized with Anx5, anti-CD41 and anti-glycophorin antibodies, respectively
Practical information
- General public
- Free
Organizer
- Prof. Horst Vogel, LCPPM
Contact
- Verena Tabet