Molecular Recalibration of PD-1+ Antigen-Specific T Cells from Blood and Liver

Mol Ther. 2018 Nov 7;26(11):2553-2566. doi: 10.1016/j.ymthe.2018.08.013. Epub 2018 Aug 16.


Checkpoint inhibitors and adoptive cell therapy provide promising options for treating solid cancers such as HBV-related HCC, but they have limitations. We tested the potential to combine advantages of each approach, genetically reprogramming T cells specific for viral tumor antigens to overcome exhaustion by down-modulating the co-inhibitory receptor PD-1. We developed a novel lentiviral transduction protocol to achieve preferential targeting of endogenous or TCR-redirected, antigen-specific CD8 T cells for shRNA knockdown of PD-1 and tested functional consequences for antitumor immunity. Antigen-specific and intrahepatic CD8 T cells transduced with lentiviral (LV)-shPD-1 consistently had a marked reduction in PD-1 compared to those transduced with a control lentiviral vector. PD-1 knockdown of human T cells rescued antitumor effector function and promoted killing of hepatoma cells in a 3D microdevice recapitulating the pro-inflammatory PD-L1hi liver microenvironment. However, upon repetitive stimulation, PD-1 knockdown drove T cell senescence and induction of other co-inhibitory pathways. We provide the proof of principle that T cells with endogenous or genetically engineered specificity for HBV-associated HCC viral antigens can be targeted for functional genetic editing. We show that PD-1 knockdown enhances immediate tumor killing but is limited by compensatory engagement of alternative co-inhibitory and senescence program upon repetitive stimulation.

Keywords: 3D models; HBV; HCC; PD-1; TCR-redirected T cells; anti-tumor immunity; cell therapy; checkpoints; genetic modification; immunotherapy; shRNA knockdown.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Neoplasm / immunology
  • Antigens, Neoplasm / therapeutic use
  • Antigens, Viral / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Carcinoma, Hepatocellular / immunology
  • Carcinoma, Hepatocellular / pathology
  • Carcinoma, Hepatocellular / therapy*
  • Carcinoma, Hepatocellular / virology
  • Genetic Vectors / genetics
  • Hepatitis B virus / immunology
  • Hepatitis B virus / pathogenicity
  • Hepatitis B, Chronic / immunology
  • Hepatitis B, Chronic / pathology
  • Hepatitis B, Chronic / therapy*
  • Hepatitis B, Chronic / virology
  • Humans
  • Immunotherapy, Adoptive / methods
  • Lentivirus / genetics
  • Liver / immunology
  • Liver / metabolism
  • Liver Neoplasms / immunology
  • Liver Neoplasms / pathology
  • Liver Neoplasms / therapy*
  • Liver Neoplasms / virology
  • Programmed Cell Death 1 Receptor / genetics
  • Programmed Cell Death 1 Receptor / immunology*
  • Programmed Cell Death 1 Receptor / therapeutic use
  • Receptors, Antigen, T-Cell / immunology
  • Receptors, Antigen, T-Cell / therapeutic use*
  • Tumor Microenvironment / genetics
  • Tumor Microenvironment / immunology


  • Antigens, Neoplasm
  • Antigens, Viral
  • PDCD1 protein, human
  • Programmed Cell Death 1 Receptor
  • Receptors, Antigen, T-Cell