Extracellular vesicles and microvilli in the immune synapse

Area of Science:

• Immunology
• Cell Biology
• Molecular Biology

Background:

• The immune synapse (IS) is a critical contact zone between T cells and antigen-presenting cells (APCs) for immune signal transmission.
• T cell receptor (TCR) engagement with antigen on APCs initiates IS formation, leading to T cell activation and effector functions.
• Extracellular vesicles (EV) are increasingly recognized as key mediators of intercellular communication within the IS.

Purpose of the Study:

• To review and emphasize recent findings on extracellular vesicles (EV) generated at the immune synapse (IS).
• To discuss the role of microvilli/lamellipodium-produced EV in immune cell communication.
• To explore the signals and structural requirements for polarized EV secretion at the IS.

Main Methods:

• Literature review focusing on recent advancements in immune synapse and extracellular vesicle research.
• Analysis of studies investigating EV biogenesis and function at cell-cell contact sites.
• Discussion of signaling pathways and cytoskeletal dynamics involved in polarized EV secretion.

Main Results:

• Extracellular vesicles (EV) secreted from both T lymphocytes and APCs carry bioactive molecules that modulate recipient cell responses.
• Specific EV populations, particularly those originating from microvilli and lamellipodia, play significant roles in intercellular signaling at the IS.
• The architecture of the immune synapse is essential for directing the polarized secretion of EV into the synaptic cleft.

Conclusions:

• Extracellular vesicles (EV) are vital components of immune cell communication, acting as messengers at the immune synapse (IS).
• Microvilli/lamellipodium-derived EV represent a significant class of signaling mediators at the IS, influencing T cell activation and apoptosis.
• The immune synapse provides a specialized microenvironment that facilitates targeted EV release and intercellular cue transfer.