Mapping the stochastic sequence of individual ligand-receptor binding events to cellular activation: T cells act on the rare events.
Sci Signal
; 12(564)2019 01 15.
Article
em En
| MEDLINE
| ID: mdl-30647147
ABSTRACT
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.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Peptídeos
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Ativação Linfocitária
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Receptores de Antígenos de Linfócitos T
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Linfócitos T
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Transdução de Sinais
Limite:
Animals
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article