The Lifeact-EGFP mouse is a translationally controlled fluorescent reporter of T cell activation
It has become increasingly evident that T cell functions are subject to translational control in addition to transcriptional regulation. Here, by using live imaging of CD8+ T cells isolated from the Lifeact-EGFP mouse, we show that T cells exhibit a gain in fluorescence intensity following engagement of cognate tumour target cells. The GFP signal increase is governed by Erk1/2-dependent distal T cell receptor (TCR) signalling and its magnitude correlates with IFN-γ and TNF-α production, which are hallmarks of T cell activation. Enhanced fluorescence was due to increased translation of Lifeact-EGFP protein, without an associated increase in its mRNA. Activation-induced gains in fluorescence were also observed in naïve and CD4+ T cells from the Lifeact-EGFP reporter, and were readily detected by both flow cytometry and live cell microscopy. This unique, translationally controlled reporter of effector T cell activation simultaneously enables tracking of cell morphology, F-actin dynamics and activation state in individual migrating T cells. It is a valuable addition to the limited number of reporters of T cell dynamics and activation, and opens the door to studies of translational activity and heterogeneities in functional T cell responses in situ.
|Authors||Galeano Nino, Jorge Luis; Tay, Szun S.; Tearle, Jacqueline L. E.; Xie, Jianling; Govendir, Matt A.; Kempe, Daryan; Mazalo, Jessica; Drew, Alexander P.; Colakoglu, Feyza; Kummerfeld, Sarah K.; Proud, Christopher G.; Biro, Mate|
|Responsible Garvan Author|
|Publisher Name||JOURNAL OF CELL SCIENCE|
|URL link to publisher's version||https://jcs.biologists.org/content/joces/133/5/jcs238014.full.pdf|