Issues

Sánchez-Paulete and colleagues showed that basic leucine zipper transcription factor, ATF-like 3 (BATF3)–dependent dendritic cells (DC) are required for the basal cross-priming of tumor antigens to CTLs and upregulation of programmed cell death 1 (PD-1) and CD137 by CTLs, thereby improving CTL sensitivity to immunostimulatory mAbs. Batf3^−/− mice were resistant to treatment with anti–PD-1 or anti-CD137 mAbs, whereas enhancement of BATF3-dependent DC expansion and activation increased the surface expression of PD-1 and CD137 on antigen-specific CD8⁺ tumor-infiltrating lymphocytes and synergistically promoted the antitumor activity of anti-CD137 and anti–PD-1 immunotherapy. These findings suggest that strategies to increase BATF3-dependent DC cross-priming may potentiate the clinical efficacy of mAb tumor immunotherapy. For details, please see the article by Sánchez-Paulete and colleagues on page 71.