Imaging the Human Immunological Synapse

Area of Science:

• Immunology
• Cell Biology
• Microscopy

Background:

• Immunological synapses (IS) are crucial for adaptive immune responses, mediating communication between antigen-presenting cells (APCs) and T lymphocytes.
• Understanding the dynamic events during IS formation is essential for deciphering immune cell function and dysfunction.
• Current imaging techniques face challenges in capturing the early stages and complex dynamics of IS formation in a biologically relevant context.

Purpose of the Study:

• To develop and validate a robust protocol for generating and imaging immunological synapses (IS).
• To capture and analyze the initial formation stages and subsequent trafficking events within APC-T cell conjugates.
• To provide a method that enhances image quality and temporal resolution for studying IS dynamics.

Main Methods:

• Utilized Jurkat cells and Staphylococcus enterotoxin E (SEE)-pulsed Raji cells to model T cell-APC synaptic conjugates.
• Employed cell-to-cell conjugation followed by time-lapse acquisition using wide-field fluorescence microscopy (WFFM).
• Applied post-acquisition deconvolution for image processing to improve signal-to-noise ratio and temporal resolution.

Main Results:

• Achieved enhanced signal-to-noise ratio and temporal resolution in IS imaging.
• Enabled synchronized acquisition of multiple fluorochromes in forming synaptic conjugates.
• Demonstrated compatibility with downstream immunofluorescence staining and advanced microscopy techniques like LSCM.

Conclusions:

• The presented protocol effectively models and visualizes key events in immunological synapse formation.
• The method offers improved imaging capabilities for studying complex cell-cell interactions in a near-physiological setting.
• This approach provides a valuable tool for immunological research, despite limitations in Z-axis imaging.