Immunological synapse arrays: patterned protein surfaces that modulate immunological synapse structure formation in T...

Area of Science:

• Immunology
• Cellular Biology
• Biophysics

Background:

• T cell activation depends on peptide recognition by T cell receptors (TCRs) on antigen-presenting cells (APCs).
• This interaction forms the immunological synapse (IS), a specialized structure at the T cell-APC interface.
• The influence of the IS's physical structure on T cell function, beyond ligand quantity/quality, is not fully understood.

Purpose of the Study:

• To investigate whether the physical arrangement of TCR ligands at the T cell-APC interface affects T cell functional responses.
• To model T cell-APC interactions using patterned protein surfaces to control ligand presentation.

Main Methods:

• Creation of multicomponent protein surfaces with lithographically defined patterns of tethered TCR ligands (anti-CD3) and ICAM-1.
• Seeding of CD4(+) T cells onto these patterned surfaces to mimic T cell-APC interactions.
• Analysis of T cell polarization, migration, IS formation, and functional responses (proliferation, cytokine secretion) based on ligand pattern.

Main Results:

• T cells formed polarized structures and migrated on the patterned surfaces.
• T cells interacting with focal spots of TCR ligand formed stable contacts, proliferated, and secreted cytokines.
• T cells encountering patterns that prevented ligand clustering showed unstable contacts, aberrant signaling, and reduced IFN-gamma production.

Conclusions:

• The physical pattern of TCR ligand presentation significantly modulates IS structure and T cell function.
• Focal clustering of TCR ligands, characteristic of a mature IS, appears necessary for robust T cell activation and cytokine production.
• These findings highlight the importance of the IS's physical architecture in regulating T cell responses.