VNUT-mediated ATP release suppresses T helper 1 (T _H 1) cell differentiation via the P2X7R-JNK-FOXO3a-Eomes signaling cascade

Extracellular ATP (eATP), a well-recognized danger signal and immune activator, is implicated in the activation, differentiation, and function of T cells, directly or indirectly. Yet, how T cells release ATP themselves and its effects remain poorly investigated. Here, we found vesicular nucleotide transporter (VNUT), critical for vesicular ATP storage/release, is highly expressed in T_H1 cells and selectively restricts their differentiation and effector functions. Mechanistically, VNUT facilitates lysosomal ATP import and its extracellular release upon T cell receptor engagement. This eATP then activates the purinergic receptor P2X7R and downstream SRC kinase, triggering a signaling cascade involving heightened Ca²⁺ influx and hyperphosphorylation of JNK and FOXO3a, which ultimately impairs Eomes-directed IFN-γ production in T_H1 cells. Genetic/pharmacological of VNUT inhibition significantly potentiates T_H1 effector functions against <i>Listeria</i> infection and transplanted tumors. These findings identify VNUT as a critical checkpoint in limiting T_H1 immunity, coupling vesicular ATP transport to transcriptional control via the P2X7R-JNK-FOXO3a-Eomes axis, offering a target for treating infection and cancer.