Breakdown of adaptive immunotolerance induces hepatocellular carcinoma in HBsAg-tg mice

Nat Commun. 2019 Jan 15;10(1):221. doi: 10.1038/s41467-018-08096-8.

Abstract

Hepatitis B virus (HBV) can induce chronic inflammation, cirrhosis, and eventually hepatocellular carcinoma (HCC). Despite evidence suggesting a link between adaptive immunity and HBV-related diseases in humans, the immunopathogenic mechanisms involved are seldom described. Here we show that expression of TIGIT, a promising immune checkpoint in tumor immunotherapy, increases with age on hepatic CD8+ T cells in HBsAg-transgenic (HBs-tg) mice whose adaptive immune system is tolerant to HBsAg. TIGIT blockade or deficiency leads to chronic hepatitis and fibrosis, along with the emergence of functional HBsAg-specific cytotoxic T lymphocytes (CTLs), suggesting adaptive immune tolerance could be broken by TIGIT blockade or deficiency. Importantly, HBsAg vaccination further induces nonresolving inflammation and HCC in a CD8+ T cell-dependent manner in TIGIT-blocked or -deficient HBs-tg mice. Therefore, CD8+ T cells play an important role in adaptive immunity-mediated tumor progression and TIGIT is critical in maintenance of liver tolerance by keeping CTLs in homeostatic balance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptive Immunity
  • Animals
  • CD8-Positive T-Lymphocytes / physiology*
  • Carcinoma, Hepatocellular / immunology*
  • Carcinoma, Hepatocellular / virology
  • Female
  • Hepatitis B Vaccines
  • Hepatitis B, Chronic / immunology*
  • Liver Neoplasms, Experimental / immunology*
  • Liver Neoplasms, Experimental / virology
  • Male
  • Mice, Inbred C57BL
  • Mice, Nude
  • Mice, Transgenic
  • Receptors, Immunologic / physiology*

Substances

  • Hepatitis B Vaccines
  • Receptors, Immunologic
  • T cell Ig and ITIM domain protein, mouse