Multidimensional analyses reveal distinct immune microenvironment in hepatitis B virus-related hepatocellular carcinoma.

BACKGROUND AND AIMS

Chronic inflammation induced by chronic hepatitis B virus (HBV) infection increases the risk of hepatocellular carcinoma (HCC). However, little is known about the immune landscape of HBV-related HCC and its influence on the design of effective cancer immunotherapeutics.

METHODS

We interrogated the immune microenvironments of HBV-related HCC and non-viral-related HCC using immunohistochemistry and cytometry by time-of-flight (CyTOF). On identifying unique immune subsets enriched in HBV-related HCC, we further interrogated their phenotypes and functions using next-generation sequencing (NGS) and in vitro T-cell proliferation assays.

RESULTS

In-depth interrogation of the immune landscapes showed that regulatory T cells (T) and CD8 resident memory T cells (T) were enriched in HBV-related HCC, whereas Tim-3CD8 T cells and CD244 natural killer cells were enriched in non-viral-related HCC. NGS of isolated T and T from HBV-related HCC and non-viral-related HCC identified distinct functional signatures associated with T-cell receptor signalling, T-cell costimulation, antigen presentation and programmed cell death protein 1 (PD-1) signalling. T and T from HBV-related HCC expressed more PD-1 and were functionally more suppressive and exhausted than those from non-virus-related HCC. Furthermore, immunosuppression by PD-1 T could be reversed with anti-PD-1 blockade. Using multiplexed tissue immunofluorescence, we further demonstrated that T and T contributed to overall patient survival: T were associated with a poor prognosis and T were associated with a good prognosis in HCC.

CONCLUSION

We have shown that the HBV-related HCC microenvironment is more immunosuppressive and exhausted than the non-viral-related HCC microenvironment. Such in-depth understanding has important implications in disease management and appropriate application of immunotherapeutics.