Progressive enhancement of kinetic proofreading in T cell antigen discrimination from receptor activation to DAG generation
Abstract
T cells use kinetic proofreading to discriminate antigens by converting small changes in antigen binding lifetime into large differences in cell activation, but where in the signaling cascade this computation is performed is unknown. Previously, we developed a light-gated immune receptor to probe the role of ligand kinetics in T cell antigen signaling. We found significant kinetic proofreading at the level of the signaling lipid diacylglycerol (DAG) but lacked the ability to determine where the multiple signaling steps required for kinetic discrimination originate in the upstream signaling cascade (Tischer and Weiner, 2019). Here we uncover where kinetic proofreading is executed by adapting our optogenetic system for robust activation of early signaling events. We find the strength of kinetic proofreading progressively increases from Zap70 recruitment to LAT clustering to downstream DAG generation. Leveraging the ability of our system to rapidly disengage ligand binding, we also measure slower reset rates for downstream signaling events. These data suggest a distributed kinetic proofreading mechanism, with proofreading steps both at the receptor and at slower resetting downstream signaling complexes that could help balance antigen sensitivity and discrimination.
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Article and author information
Author details
Funding
National Institutes of Health (GM118167)
- Orion David Weiner
National Science Foundation (DBI-1548297)
- Orion David Weiner
Novo Nordisk Foundation Center for Basic Metabolic Research (NNF17OC0028176)
- Orion David Weiner
National Science Foundation (Predoctoral Fellowship)
- Jason P Town
Achievement Rewards for College Scientists Foundation (Predoctoral Fellowship)
- Derek M Britain
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2022, Britain et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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