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bioRxiv · 10.1101/203950

T Cell Calcium Dynamics Visualized in a Ratiometric tdTomato-GCaMP6f Transgenic Reporter Mouse

Dong, T. X.·Cahalan, M. D.·Parker, I.·Dynes, J. L.·Othy, S.·Jairaman, A.·Skupsky, J.·Zavala, A.
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Abstract

Calcium is an essential cellular messenger that regulates numerous functions in living organisms. Here we describe development and characterization of \"Salsa6f\", a fusion of GCaMP6f and tdTomato optimized for cell tracking while monitoring cytosolic Ca2+, and a transgenic Ca2+ reporter mouse with Salsa6f floxed and targeted to the Rosa26 locus for expression in specific cell types. Using CD4-Cre-Salsa6f mice, we report normal development and function of T cells expressing Salsa6f and demonstrate Ca2+ signaling dynamics during T cell receptor engagement in naive T cells, helper Th17 T cells and regulatory T cells. Salsa6f expression also revealed functional expression of mechanosensitive Piezo1 channels in T cells. Transgenic expression of Salsa6f enables ratiometric imaging of Ca2+ signals in complex tissue environments found in vivo. Deep tissue two-photon imaging of T cells in the steady-state lymph node revealed a highly localized Ca2+ signaling behavior (\"sparkles\") as cells migrate.

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Dong, T. X., Cahalan, M. D., Parker, I., Dynes, J. L., Othy, S., Jairaman, A., Skupsky, J., Zavala, A.. 2017-10-16. T Cell Calcium Dynamics Visualized in a Ratiometric tdTomato-GCaMP6f Transgenic Reporter Mouse. https://doi.org/10.1101/203950

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