Inflammation-induced IgA cells dismantle anti-liver cancer immunity

Authors: Shabnam Shalapour, Xue-Jia Lin, Ingmar N. Bastian, John Brain, Alastair D. Burt, Alexander A. Aksenov, Alison F. Vrbanac, Weihua Li, Andres Perkins, Takaji Matsutani, Zhenyu Zhong, Debanjan Dhar, Jose A. Navas-Molina, Jun Xu, Rohit Loomba, Michael Downes, Ruth T. Yu, Ronald M. Evans, Pieter C. Dorrestein, Rob Knight, Christopher Benner, Quentin M. Anstee, Michael Karin


The role of adaptive immunity in early cancer development is controversial. Here we show that chronic inflammation and fibrosis in humans and mice with non-alcoholic fatty liver disease is accompanied by accumulation of liver-resident immunoglobulin-A-producing (IgA+) cells. These cells also express programmed death ligand 1 (PD-L1) and interleukin-10, and directly suppress liver cytotoxic CD8+ T lymphocytes, which prevent emergence of hepatocellular carcinoma and express a limited repertoire of T-cell receptors against tumour-associated antigens. Whereas CD8+ T-cell ablation accelerates hepatocellular carcinoma, genetic or pharmacological interference with IgA+ cell generation attenuates liver carcinogenesis and induces cytotoxic T-lymphocyte-mediated regression of established hepatocellular carcinoma. These findings establish the importance of inflammation-induced suppression of cytotoxic CD8+ T-lymphocyte activation as a tumour-promoting mechanism.

Source: Nature; 2017