Insights into T cell recognition of antigen: Significance of two-dimensional kinetic parameters

• Main Authors: Lindsay J Edwards, Veronika I Zarnitsyna, Jennifer D Hood, Brian eEvavold, Cheng eZhu
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2012-04-01
• Series: Frontiers in Immunology
• Subjects: Kinetics; Affinity; T cell activation; 2D binding; molecular interaction
• Online Access: http://journal.frontiersin.org/Journal/10.3389/fimmu.2012.00086/full

The kinetic parameters governing T cell activation have been intensely studied for over a decade. However, the details of how the various aspects of receptor:ligand interactions culminate in T cell activation remains shrouded in mystery. Initial measurements were generated using surface plasmon resonance, a three-dimensional (3D) technique in which fluid-phase receptors and ligands are removed from their cellular environment. This approach demonstrated kinetics of TCR:pMHC interaction with relatively low affinities and slow off-rates for agonist peptides. Newer generation techniques have analyzed TCR:pMHC interactions in two dimensions (2D), with both proteins anchored in apposing plasma membranes. These approaches reveal TCR:pMHC interaction kinetics that are of high affinity and exhibit rapid off-rates upon interaction with agonist ligands. Importantly, 2D binding parameters correlate better with T cell functional responses to a spectrum of ligands than 3D measures.