Details

Autor(en) / Beteiligte

• Lin, Jenny J Y
• Low-Nam, Shalini T
• Alfieri, Katherine N
• McAffee, Darren B
• Fay, Nicole C
• Groves, Jay T

Titel

Mapping the stochastic sequence of individual ligand-receptor binding events to cellular activation: T cells act on the rare events

Ist Teil von

• Science signaling, 2019-01, Vol.12 (564)

Ort / Verlag

United States

Erscheinungsjahr

2019

Quelle

MEDLINE

Beschreibungen/Notizen

• T cell receptor (TCR) binding to agonist peptide major histocompatibility complex (pMHC) triggers signaling events that initiate T cell responses. This system is remarkably sensitive, requiring only a few binding events to successfully activate a cellular response. On average, activating pMHC ligands exhibit mean dwell times of at least a few seconds when bound to the TCR. However, a T cell accumulates pMHC-TCR interactions as a stochastic series of discrete, single-molecule binding events whose individual dwell times are broadly distributed. With activation occurring in response to only a handful of such binding events, individual cells are unlikely to experience the average binding time. Here, we mapped the ensemble of pMHC-TCR binding events in space and time while simultaneously monitoring cellular activation. Our findings revealed that T cell activation hinges on rare, long-dwell time binding events that are an order of magnitude longer than the average agonist pMHC-TCR dwell time. Furthermore, we observed that short pMHC-TCR binding events that were spatially correlated and temporally sequential led to cellular activation. These observations indicate that T cell antigen discrimination likely occurs by sensing the tail end of the pMHC-TCR binding dwell time distribution rather than its average properties.