Extended Data Fig. 10: Targeting PTPN2 and SOCS1 and model of REGNASE-1 functions in tumour-specific CD8⁺ T cells.

a, Immunoblot analysis of REGNASE-1, PTPN2 and SOCS1 expression in OT-I cells cultured in vitro, 3 days after transduction with control sgRNA, Ptpn2 and Regnase-1 sgRNAs (left) or Socs1 and Regnase-1 sgRNAs (right). HSP90 is used as a loading control. b, Immunoblot analysis of REGNASE-1, BATF, SOCS1 and PTPN2 expression in OT-I cells transduced with control sgRNA or Regnase-1 sgRNA, cultured in vitro for 3 days after viral transduction. β-Actin is used as a loading control. c, REGNASE-1 is a major negative regulator of CD8⁺ T cell antitumour responses, and TCR and IL-2 inhibit its expression and activity. Deletion of REGNASE-1 unleashes a potent therapeutic efficacy of engineered tumour-specific CD8⁺ T cells against cancers, by coordinating transcriptional and metabolic programs to achieve greatly improved cell accumulation and function. As a key functional target of REGNASE-1, excessive BATF drives robust cell accumulation and effector function—in part through enhancing mitochondrial metabolism—in REGNASE-1-null CD8⁺ T cells. REGNASE-1 deletion also reprograms cells to acquire increased gene signatures associated with naive or memory cells and to gain survival advantage, which contribute to the improved persistence of REGNASE-1-null effector CD8⁺ T cells. Targeting PTPN2 and SOCS1 (not depicted here) acts in coordination with REGNASE-1 inhibition to promote CD8⁺ T cell antitumour responses. Data are representative of three independent experiments (a, b).