Actin stabilizer TAGLN2 potentiates adoptive T cell therapy by boosting the inside-out costimulation via lymphocyte function-associated antigen-1

T cells to kill the intercellular adhesion molecule-1 (ICAM-1)-positive/OVA-presenting E0771 cells, but not ICAM-1-negative OVA-B16F10 cells, suggesting an 'inside-out' activation of LFA-1, which causes more efficient immunological synapse formation between T cells and tumor cells. Notably, recombinant TAGLN2 fused with the protein transduction domain (TG2P) overcame the disadvantages of viral gene delivery, leading to a significant reduction in tumor growth in mice. TG2P also potentiated the CD19-targeted, chimeric antigen receptor (CAR)-modified T cells to kill Raji B-lymphoma cells. Our findings indicate that activating the TAGLN2-actin-LFA-1 axis is an effective strategy to potentiate the adoptive T-cell immunotherapy.