isMap - immunological synapse map analysis program.

Area of Science:

• Immunology
• Computational Biology
• Cell Biology

Background:

• T cell activation is crucial for adaptive immunity, involving antigen recognition by T cells and antigen-presenting cells (APCs).
• The immunological synapse (IS) is a specialized interface formed during T cell-APC interaction, organizing protein interactions that dictate T cell responses.
• Current tools for quantitative analysis and visualization of the IS molecular architecture are limited.

Purpose of the Study:

• To introduce isMap, a computational framework for automated analysis of T cell activation and IS formation.
• To quantitatively analyze molecular organization and protein dynamics within the IS.
• To validate isMap's utility in dissecting IS functional organization and ligand-receptor redistribution.

Main Methods:

• Development of isMap, a computational framework for automated cell segmentation and quantification.
• Application of isMap to analyze T cell activation and IS formation on supported lipid bilayers (SLBs).
• Utilized fluorescence intensity measurements, colocalization analysis, and radial averaging to quantify protein distribution and dynamics.

Main Results:

• isMap successfully validated known CD58 and T cell receptor (TCR) clustering dynamics during CD8+ T cell activation.
• Demonstrated PD-L1's dynamic redistribution, initially across the IS and later accumulating with TCR in the mature synapse center.
• Quantified the central clustering and TCR colocalization of ICOSL, CD80, and CD86, establishing their order of colocalization (ICOSL>CD86>CD80).

Conclusions:

• isMap is a valuable tool for dissecting the functional organization of the immunological synapse.
• The study highlights the dynamic redistribution of ligand-receptor pairs during T cell activation.
• Findings provide insights into the molecular architecture and protein dynamics governing T cell responses.