EVs

biology
computer sciences
genetics
Published

17 July 2024

Extracellular Vesicles (EVs)

Extracellular Vesicles (EVs) are small membrane-bound particles released by cells into the extracellular environment. They play crucial roles in intercellular communication, transferring proteins, lipids, and genetic material between cells.

Types of EVs

  1. Exosomes:
    • Diameter: 30-150 nm
    • Origin: Formed inside multivesicular bodies (MVBs) and released when MVBs fuse with the plasma membrane.
  2. Microvesicles:
    • Diameter: 100-1000 nm
    • Origin: Bud directly from the plasma membrane.
  3. Apoptotic Bodies:
    • Diameter: 50-5000 nm
    • Origin: Released during programmed cell death (apoptosis).

Key Functions of EVs

  • Intercellular Communication:
    • EVs transfer proteins, lipids, and RNAs to recipient cells, influencing their behavior and function.
  • Immune Response Modulation:
    • EVs can carry antigens and other molecules that modulate the immune system, either activating or suppressing immune responses.
  • Disease Biomarkers:
    • EVs can serve as biomarkers for various diseases, including cancer, due to their content reflecting the state of the parent cell.

Mechanisms of EV Uptake

Recipient cells can take up EVs through several mechanisms:

  • Endocytosis:
    • The EVs are internalized via clathrin-mediated or caveolin-mediated endocytosis.
  • Membrane Fusion:
    • Direct fusion of the EV membrane with the plasma membrane of the recipient cell, releasing the EV contents into the cytoplasm.
  • Receptor-Mediated Uptake:
    • Specific interactions between surface proteins on EVs and receptors on the recipient cell surface.

EVs in Symbiosis

In symbiotic relationships, EVs are crucial for the communication between symbionts and hosts. They can transfer signaling molecules that regulate:

  • Immune responses
  • Nutrient exchange
  • Gene expression

In bioinformatics research, analyzing the cargo of EVs, such as proteins and RNAs, can provide insights into the molecular mechanisms underlying these interactions.

Research Techniques

  • Isolation of EVs:
    • Differential centrifugation: Sequential centrifugation steps to separate EVs based on size and density.
    • Density gradient centrifugation: Further purifies EVs by their buoyant density.
    • Molecular exclusion chromatography: Separates EVs based on size exclusion.
  • Characterization of EVs:
    • Nanoparticle Tracking Analysis (NTA): Measures the size and concentration of EVs.
    • Transmission Electron Microscopy (TEM): Visualizes the morphology of EVs.
  • Cargo Identification:
    • Proteomics: Identifies proteins within EVs.
    • Transcriptomics: Analyzes RNA content in EVs.

Extracellular vesicles represent a dynamic and versatile component of intercellular communication, with significant implications for both basic biological research and clinical applications. Understanding their roles and mechanisms is essential for advancing knowledge in fields such as immunology, oncology, and symbiosis.