PT  - JOURNAL ARTICLE
AU  - Joseph R. Egan
AU  - Enas Abu-Shah
AU  - Omer Dushek
AU  - Tim Elliott
AU  - Ben D. MacArthur
TI  - Fluctuations in TCR and pMHC interactions regulate T cell activation
AID  - 10.1101/2021.02.09.430441
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.02.09.430441
4099  - http://biorxiv.org/content/early/2021/07/05/2021.02.09.430441.short
4100  - http://biorxiv.org/content/early/2021/07/05/2021.02.09.430441.full
AB  - Adaptive immune responses depend on interactions between T cell receptors (TCRs) and peptide major-histocompatibility complex (pMHC) ligands located on the surface of T cells and antigen presenting cells (APCs) respectively. As TCRs and pMHCs are often only present at low copy-numbers their interactions are inherently stochastic, yet the role of stochastic fluctuations on T cell function is unclear. Here we introduce a minimal stochastic model of T cell activation that accounts for serial TCR-pMHC engagement, reversible TCR conformational change and TCR aggregation. Analysis of this model indicates that it is not the strength of binding between the T cell and the APC cell per se that elicits an immune response, but rather the information imparted to the T cell from the encounter, as assessed by the entropy rate of the TCR-pMHC binding dynamics. This view provides an information-theoretic interpretation of T cell activation that explains a range of experimental observations. Based on this analysis we propose that effective T cell therapeutics may be enhanced by optimizing the inherent stochasticity of TCR-pMHC binding dynamics.Competing Interest StatementThe authors have declared no competing interest.