A Potential GPER1–Redox Axis in Lymphocyte Immunity: Mitochondrial Signaling and Context-Dependent Adaptation

Redox signaling is a key regulator of lymphocyte activation and adaptation, in which reactive oxygen species (ROS) function not only as mediators of oxidative stress but also as context-dependent signaling molecules. G protein-coupled estrogen receptor (GPER1) is an estrogen-responsive receptor with emerging roles in immune regulation, yet how GPER1 signaling intersects with cellular redox networks in lymphocytes remains incompletely understood. Evidence from different biological systems supports a relationship between GPER1 signaling and redox regulation, whereas direct evidence connecting GPER1 to mitochondrial ROS (mtROS) regulation in lymphocytes remains to be established. This review examines the potential intersection between GPER1 signaling, redox regulation, and lymphocyte immunity. We first summarize current evidence regarding GPER1 expression and immunomodulatory functions, followed by a discussion of signaling mechanisms through which GPER1 may influence ROS generation, antioxidant responses, and mitochondrial function. Particular emphasis is placed on mitochondrial redox signaling and its context-dependent roles in lymphocyte activation, metabolic adaptation, and functional states. We propose that GPER1-associated redox regulation may influence lymphocyte adaptation to changing signaling and metabolic demands, although this potential relationship has not been directly established in normal lymphocytes. Further investigation of this potential relationship may provide insights into the role of GPER1-associated redox signaling in lymphocyte function and chronic inflammatory diseases.