T cell triggering: insights from 2D kinetics analysis of molecular interactions

Area of Science:

• Immunology
• Molecular Biology
• Biophysics

Background:

• T cell receptor (TCR) interaction with peptide-MHC (pMHC) is crucial for adaptive immunity.
• Kinetic analysis traditionally used 3D solution-based methods.
• Recent advancements allow 2D kinetic analysis on live T cells.

Purpose of the Study:

• To review new 2D kinetic data for TCR-pMHC interactions.
• To discuss the impact of 2D data on existing T cell discrimination models.
• To compare kinetic parameters obtained from 2D and 3D methods.

Main Methods:

• Analysis of T cell receptor (TCR) and peptide-MHC (pMHC) interactions.
• Utilizing three-dimensional (3D) solution-based methods.
• Employing two-dimensional (2D) methods on live T cells with surrogate antigen-presenting cells or lipid bilayers.

Main Results:

• 2D kinetic parameters show broader ranges of affinities and on-rates compared to 3D methods.
• 2D off-rates are orders of magnitude faster than those measured in 3D.
• Functional differences in pMHCs are more pronounced in 2D kinetic measurements.

Conclusions:

• 2D kinetic data provides a more biologically relevant perspective on TCR-pMHC interactions.
• Differences in 2D kinetics challenge and refine current models of T cell signaling and discrimination.
• Future models should incorporate 2D kinetic insights for accurate T cell response prediction.