Virus-induced hepatocellular carcinomas cause antigen-specific local tolerance
Gerald Willimsky, … , Johanna Gellermann, Thomas Blankenstein
Gerald Willimsky, … , Johanna Gellermann, Thomas Blankenstein
Published February 1, 2013
Citation Information: J Clin Invest. 2013;123(3):1032-1043. https://doi.org/10.1172/JCI64742.
View: Text | PDF
Research Article Oncology

Virus-induced hepatocellular carcinomas cause antigen-specific local tolerance

Abstract

T cell surveillance is often effective against virus-associated tumors because of their high immunogenicity. It is not clear why surveillance occasionally fails, particularly against hepatitis B virus– or hepatitis C virus–associated hepatocellular carcinoma (HCC). We established a transgenic murine model of virus-induced HCC by hepatocyte-specific adenovirus-induced activation of the oncogenic SV40 large T antigen (TAg). Adenovirus infection induced cytotoxic T lymphocytes (CTLs) targeted against the virus and TAg, leading to clearance of the infected cells. Despite the presence of functional, antigen-specific T cells, a few virus-infected cells escaped immune clearance and progressed to HCC. These cells expressed TAg at levels similar to HCC isolated from neonatal TAg-tolerant mice, suggesting that CTL clearance does not select for cells with low immunogenicity. Virus-infected mice revealed significantly greater T cell infiltration in early-stage HCC compared with that in late-stage HCC, demonstrating progressive local immune suppression through inefficient T cell infiltration. Programmed cell death protein-1 (PD-1) and its ligand PD-L1 were expressed in all TAg-specific CD8+ T cells and HCC, respectively, which contributed to local tumor-antigen-specific tolerance. Thus, we have developed a model of virus-induced HCC that may allow for a better understanding of human HCC.

Authors

Gerald Willimsky, Karin Schmidt, Christoph Loddenkemper, Johanna Gellermann, Thomas Blankenstein

×

Figure 3

Ad.Cre-mediated TAg activation in LoxP-TAg mice induces functional pIV-specific CTLs, which increase with tumor burden.

Options: View larger image (or click on image) Download as PowerPoint
Ad.Cre-mediated TAg activation in LoxP-TAg mice induces functional pIV-s...
CTL activity against pIV alone or simultaneously against pIV and adenovirus dbp43 was analyzed in vivo. For simultaneous detection of CTL activity against pIV and dbp43, nonloaded and pIV- and dbp43-loaded CD45.1 congenic spleen cells (1 × 107 each) were labeled with different amounts of CFSE and injected into the indicated mice, and 18 hours later the ratio between different populations was determined by flow cytometry, gated on CD45.1+ cells. The percentage of specific killing is indicated. In some experiments, only pIV-specific CTLs were analyzed. (A) Gating for the injected CD45.1+ spleen cells and one representative example per experimental group is shown for the simultaneous detection of pIV and dbp43 CTLs. Naive 8- to 12-week-old B6 (N), immunized 8- to 12-week-old B6 (I), and 8- to 12-week-old LoxP-TAg (Tg) mice 2, 4, 6–10, and 12–35 weeks after Ad.Cre injection were analyzed. Immunization of B6 mice was performed either by single i.p. injection of 0.5 × 107 to 1 × 107 16.113 cells or simultaneous injection of 16.113 cells (i.p.) and 1 × 109 PFUs Ad.Cre (i.v.). (B) The combined data of pIV-specific kill are shown. White circles represent LoxP-TAg mice with liver tumors larger than 5 mm in diameter. Black circles represent B6 and LoxP-TAg mice with no tumors or LoxP-TAg mice with liver tumors smaller than 5 mm in diameter. Each symbol represents 1 mouse; horizontal bars indicate mean values. Some of the B6 mice were injected with 16.113 only (asterisk). The P value at the top left of the graph represents overall significance calculated by Krusal-Wallis test. (C) The combined data of dbp43-specific kill are shown. Each symbol represents 1 mouse; horizontal bars indicate mean values. The P value at the top left of the graph represents overall significance calculated by Krusal-Wallis test.