Nur77-Tempo mice reveal T cell steady state antigen recognition.

In lymphocytes, gene expression is specifically regulated by antigen receptor signalling, making them ideal targets for use as distal T cell receptor (TCR) reporters. -Timer of cell kinetics and activity (Tocky) mice are a ground-breaking tool to report TCR-driven expression using Fluorescent Timer protein (FT). FT undergoes a time-dependent shift in its emission spectrum following translation, allowing for the temporal reporting of transcriptional events.

Antigen and checkpoint receptor engagement recalibrates T cell receptor signal strength.

How T cell receptor (TCR) signal strength modulates T cell function and to what extent this is modified by immune checkpoint blockade (ICB) are key questions in immunology. Using Nr4a3-Tocky mice, we characterized early quantitative and qualitative changes that occur in CD4 T cells in relation to TCR signaling strength. We captured how dose- and time-dependent programming of distinct co-inhibitory receptors rapidly recalibrates T cell activation thresholds and visualized the immediate effects of ICB on T cell re-activation.

Application of dual -GFP -Tocky reporter mice to study T cell receptor signaling by flow cytometry.

This protocol uses -GFP -Tocky mice to study T cell receptor (TCR) signaling using flow cytometry. It identifies the optimal mouse transgenic status and fluorochromes compatible with the dual reporter. This protocol has applications in TCR signaling, and we outline how to obtain high-quality datasets.