Hepatology. 2020 Jan 11. doi: 10.1002/hep.31112. [Epub ahead of print]
Hepatitis B virus particles activate toll-like receptor 2 signaling initial upon infection of primary human hepatocytes.
Zhang Z1,2, Trippler M1, Real CI1, Werner M1, Luo X1, Schefczyk S1, Kemper T2, Anastasiou OE1,2, Ladiges Y3, Treckmann J4, Paul A4, Baba HA5, Allweiss L3, Dandri M3, Gerken G1, Wedemeyer H1, Schlaak JF6, Lu M2, Broering R1.
Author information
1
Dept. of Gastroenterology and Hepatology, University Hospital Essen, University Duisburg-Essen, Essen, Germany.
2
Institute of Virology, University Hospital Essen, University Duisburg-Essen, Essen, Germany.
3
Dept. of Medicine, Center for Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
4
Dept. of General-, Visceral- and Transplantation Surgery, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
5
Dept. of Pathology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
6
Evangelisches Klinikum Niederrhein GmbH, Duisburg, Germany.
Abstract
To date conflicting data exist, whether hepatitis B virus (HBV) has the ability to induce innate immune responses. Here, we investigated cellular changes after the first-contact between HBV and primary human hepatocytes (PHH) in vitro and in vivo. The exposure of PHH to HBV particles resulted in nuclear translocation of NFκB, followed by the expression and secretion of inflammatory cytokines (IL1B, IL6 and TNF). UV irradiation of viral particles suppressed HBV infectivity but not the induction of cytokines in PHH, suggesting that the inoculum contains the immune inducing agent. Purified HBV particles on the whole, that were prepared from HBV DNA-positive and protein rich fractions after heparin column separation, still had immune-inducing capacity in PHH. The HBV-induced gene expression profile was similar to that induced by TLR2 ligand Pam3Cys, but different from those induced by the viral sensors TLR3 or TLR7-9. Treatment of PHH with both, HBV particles and Pam3Cys led to phosphorylation of ERK1, JNK and p38 mitogen-activated protein kinases as well as NFκB. Finally, HBV-induced gene expression could be neutralized by TLR2-specific antibodies. Of note, pre-treatment with an HBV entry inhibitor attenuated the TLR2-mediated response to HBV, suggesting a receptor binding-related mechanism. In liver-humanized uPA/SCID/beige mice challenged with HBV in vivo immune induction could only marginally be seen. Conclusions: Primary human hepatocytes are able to sense HBV particles via TLR2 leading to an activation of anti-HBV immune responses in vitro. These findings challenge the previously described stealth properties of HBV.