Store-operated calcium entry (SOCE) plays a critical role in regulating intracellular calcium signaling and is essential for immune cell functions. SOCE blockade with the pyrazole derivative BTP2 has been explored as an anti-inflammatory strategy in preclinical models, and Zegocractin (CM4620) is under clinical investigation as a CRAC channel inhibitor with activity in multiple tissues, including immune cells. However, the cell type-specific consequences of SOCE blockade under defined activation contexts remain incompletely understood. Here, we used multiplexed single-cell RNA sequencing to investigate the effects of two prototypic SOCE blockers, BTP2 and CM4620, on polyclonally stimulated, normal human peripheral blood mononuclear cells (PBMCs) in a phytohemagglutinin (PHA)-driven T-cell activation model. The data revealed that SOCE blockade suppressed cytotoxicity-associated transcriptional programs in CD8+ effector T cells and natural killer (NK) cells, restoring them to levels comparable to unstimulated cells. At the same time, SOCE blockade allowed CD4+ regulatory T cells to retain transcriptional signatures associated with immune regulation. These results indicate that, in this experimental model, SOCE blockade dampens cytotoxic programs while maintaining tolerance signatures, suggesting a potential avenue for targeted immune modulation in transplantation and other immune-mediated conditions. SIGNIFICANCE STATEMENT: Store-operated calcium entry (SOCE) is essential for immune activation, but broad immunosuppression can cause significant side effects. Using single-cell transcriptomics in a phytohemagglutinin (PHA)-driven T-cell activation model, we show that SOCE blockade with BTP2 or CM4620 suppresses pro-inflammatory and cytotoxic programs in CD8+ effector T cells and NK cells while preserving tolerance-associated pathways in CD4+ regulatory T cells. These findings suggest that SOCE blockade may provide a more targeted form of immune modulation, warranting future head-to-head comparisons with conventional immunosuppressants. Our results highlight the potential of SOCE blockers to reduce immune-mediated damage while maintaining tolerance, motivating further functional and translational studies in transplantation and other immune-mediated conditions.
Stephanou et al. (Fri,) studied this question.