Quantifying persistence in the T-cell signaling network using an optically controllable antigen receptor.

Michael J Harris,John R James,Muna Fuyal

doi:10.15252/msb.202010091

Michael J Harris, John R James + Show 1 more

Open Access

https://doi.org/10.15252/msb.202010091

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Abstract

T cells discriminate between healthy and infected cells with remarkable sensitivity when mounting an immune response, which is hypothesized to depend on T cells combining stimuli from multiple antigen‐presenting cell interactions into a more potent response. To quantify the capacity for T cells to accomplish this, we have developed an antigen receptor that is optically tunable within cell conjugates, providing control over the duration, and intensity of intracellular T‐cell signaling. We observe limited persistence within the T‐cell intracellular network on disruption of receptor input, with signals dissipating entirely in ~15 min, and directly show sustained proximal receptor signaling is required to maintain gene transcription. T cells thus primarily accumulate the outputs of gene expression rather than integrate discrete intracellular signals. Engineering optical control in a clinically relevant chimeric antigen receptor (CAR), we show that this limited signal persistence can be exploited to increase CAR‐T cell activation threefold using pulsatile stimulation. Our results are likely to apply more generally to the signaling dynamics of other cellular networks.

Highlights

The ability of cells to convert extracellular stimuli into information that can guide future decisions is an essential requirement for organisms to survive within their environment (Jordan et al, 2000)
To create our optically controlled chimeric antigen receptor, which we term an “OptoCAR”, we fused the light-sensitive LOV2 domain to the intracellular terminus of a synthetic receptor that we have previously shown can replicate the function of the native T-cell antigen receptor (TCR) complex to other CAR structures (James & Vale, 2012; James, 2018)
We have described an engineered antigen receptor that provides optical control over intracellular signaling in T cells while conjugated with antigen-presenting cells

Summary

Introduction

The ability of cells to convert extracellular stimuli into information that can guide future decisions is an essential requirement for organisms to survive within their environment (Jordan et al, 2000). External inputs are sensed by receptors that reside predominantly at the cell surface in mammalian cells, whereas their functional output is either manifested as changes in gene expression (Pope & Medzhitov, 2018), metabolism (Saxton & Sabatini, 2017), or behaviors such as cell migration (Devreotes & Horwitz, 2015). These outputs can drive long-term alterations in cell function by bringing about a new state that persists when the originating input has been removed and constitutes a memory of previous signaling (Burrill & Silver, 2010). Any potential for signals to be retained on cessation of receptor input would constitute a short-term memory, which could be observed directly when distinct inputs are separated over time providing a mechanism to combine discrete events into a more potent response

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