Metabolic regulation of hepatitis B immunopathology by myeloid-derived suppressor cells

LJ Pallett, US Gill, A Quaglia, LV Sinclair… - Nature medicine, 2015 - nature.com
LJ Pallett, US Gill, A Quaglia, LV Sinclair, M Jover-Cobos, A Schurich, KP Singh, N Thomas…
Nature medicine, 2015nature.com
Infection with hepatitis B virus (HBV) results in disparate degrees of tissue injury: the virus
can either replicate without pathological consequences or trigger immune-mediated
necroinflammatory liver damage. We investigated the potential for myeloid-derived
suppressor cells (MDSCs) to suppress T cell–mediated immunopathology in this setting.
Granulocytic MDSCs (gMDSCs) expanded transiently in acute resolving HBV, decreasing in
frequency prior to peak hepatic injury. In persistent infection, arginase-expressing gMDSCs …
Abstract
Infection with hepatitis B virus (HBV) results in disparate degrees of tissue injury: the virus can either replicate without pathological consequences or trigger immune-mediated necroinflammatory liver damage. We investigated the potential for myeloid-derived suppressor cells (MDSCs) to suppress T cell–mediated immunopathology in this setting. Granulocytic MDSCs (gMDSCs) expanded transiently in acute resolving HBV, decreasing in frequency prior to peak hepatic injury. In persistent infection, arginase-expressing gMDSCs (and circulating arginase) increased most in disease phases characterized by HBV replication without immunopathology, whilst L-arginine decreased. gMDSCs expressed liver-homing chemokine receptors and accumulated in the liver, their expansion supported by hepatic stellate cells. We provide in vitro and ex vivo evidence that gMDSCs potently inhibited T cells in a partially arginase-dependent manner. L-arginine–deprived T cells upregulated system L amino acid transporters to increase uptake of essential nutrients and attempt metabolic reprogramming. These data demonstrate the capacity of expanded arginase-expressing gMDSCs to regulate liver immunopathology in HBV infection.
nature.com