<b>Development of an Affinity-Based Probe to Profile Endogenous Human Adenosine A₃ Receptor Expression</b>

The adenosine A3 receptor (A3AR)
is a G protein-coupled
receptor (GPCR) that exerts immunomodulatory effects in pathophysiological
conditions such as inflammation and cancer. Thus far, studies toward
the downstream effects of A3AR activation have yielded
contradictory results, thereby motivating the need for further investigations.
Various chemical and biological tools have been developed for this
purpose, ranging from fluorescent ligands to antibodies. Nevertheless,
these probes are limited by their reversible mode of binding, relatively
large size, and often low specificity. Therefore, in this work, we
have developed a clickable and covalent affinity-based probe (AfBP)
to target the human A3AR. Herein, we show validation of
the synthesized AfBP in radioligand displacement, SDS-PAGE, and confocal
microscopy experiments as well as utilization of the AfBP for the
detection of endogenous A3AR expression in flow cytometry
experiments. Ultimately, this AfBP will aid future studies toward
the expression and function of the A3AR in pathologies.