Self-Assembled Lanthanide Antenna Glutathione Sensor for the Study of Immune Cells

Abstract

The small molecule 8-methoxy-2-oxo-1,2,4,5-tetrahydrocyclopenta[de]quinoline-3-carboxylic acid ( 2b ) behaves as a reactive non-fluorescent Michael acceptor, which after reaction with thiols becomes fluorescent, and an efficient Eu 3+ antenna, after self-assembling with this cation in water. This behavior makes 2b a highly selective GSH biosensor, which has demonstrated high potential for studies in murine and human cells of the immune system (CD4 + T, CD8 + T, and B cells) using flow cytometry. GSH can be monitored by the fluorescence of the product of addition to 2b (445 nm) or by the luminescence of Eu 3+ (592 nm). 2b was able to capture baseline differences in GSH intracellular levels among murine and human CD4 + T, CD8 + T, and B cells. We also successfully used 2b to monitor intracellular changes in GSH associated with the metabolic variations governing the induction of CD4 + naïve T cells into regulatory T cells (T REG ).

Exchangeable Self‐Assembled Lanthanide Antennas for PLIM Microscopy

“…However, most of self‐assembling lanthanide complexes show PL deactivation in the presence of water due to the interactions between the surrounding aqueous environment and the antenna‐lanthanide complex [6b,12] . As a result, very few examples of lanthanide antennas that self‐assemble in water have been described in the literature [12a][13] In this sense, we recently described a lanthanide antenna (8‐methoxy‐2‐oxo‐1,2‐ dihydrocyclopenta[ de ]quinoline‐3‐carboxylic acid), able to directly coordinate Tb(III) and Eu(III), sensitizing their emission in water, and useful as a luminescent sensor of biothiols for the study of human cells of the immune system by flow cytometry [14] …”

“…[6b,12] As a result, very few examples of lanthanide antennas that self-assemble in water have been described in the literature [12a] [13] In this sense, we recently described a lanthanide antenna (8-methoxy-2-oxo-1,2-dihydrocyclopenta[de]quinoline-3-carboxylic acid), able to directly coordinate Tb(III) and Eu(III), sensitizing their emission in water, and useful as a luminescent sensor of biothiols for the study of human cells of the immune system by flow cytometry. [14] In this work, we focus on developing enhanced aqueoussoluble, self-assembled, lanthanide antennas specifically designed to serve as exchangeable dyes aimed at mitigating photobleaching in PLIM microscopy in cellulo. Hence, we have developed a novel modified luminophore containing a phosphonic acid moiety (8-methoxy-2-oxo-1,2,4,5tetrahydrocyclopenta[de]quinoline-3-phosphonic acid, Figure 1).…”