COMBINATION THERAPY WITH CAPSID ALLOSTERIC
MODULATOR AND INTERFERON ALPHA PROMOTES INNATE
IMMUNE RESPONSE IN HBV-INFECTED HEPATOCYTES
Keisuke Fukutomi1, Hayato Hikita1, Tasuku Nakabori1,
Akiyoshi Shimoda1, Makoto Fukuoka1, Kazuhiro Murai1,
Takuo Yamai1, Ryoko Yamada1, Takahiro Kodama1, Ryotaro
Sakamori1, Hiroshi Suemizu2, Tomohide Tatsumi1 and
Tetsuo Takehara1, (1)Department of Gastroenterology and
Hepatology, Osaka University Graduate School of Medicine,
(2)Department of Laboratory Animal Research, Central
Institute for Experimental Animals
Background: Hepatitis B virus (HBV) avoids host intracellular
innate immune systems. It is reported that HBV pregenomic
RNA (pgRNA) can be recognized by RIG-I like receptors
(RLRs), which induce interferon (IFN) response in hepatocytes
Capsid allosteric modulators (CAMs) inhibit encapsidation
of pgRNA and the effect of CAMs on host innate immunity
remains unclear In this study, we investigated the effect of
CAM treatment on intracellular innate immune response
in HBV-infected hepatocytes. Methods: HepG2-hNTCP
cells, primary human hepatocytes (PHHs) and human liver
chimeric TK-NOG mice were infected with HBV derived from
HepAD38 7 cells or patient’s serum and treated with CAM
(Bay41-4109) alone or in combination with IFNα. Changes of
intracellular HBV core protein and cytoplasmic pgRNA levels,
gene expression levels of RLRs-mediated innate immune
signaling (i e RIG-I, MDA5, IRF3/7, IFNs and ISGs) and
antiviral effects were analyzed Results: Intracellular HBV core
protein levels decreased after CAM treatment To investigate
changes of cytoplasmic pgRNA levels by CAM treatment,
cytoplasmic and intracapsid RNA were extracted from HBVinfected
HepG2-hNTCP cells after CAM treatment RT qPCR
showed pgRNA levels increased in cytoplasm but decreased
in capsid, suggesting that extracapsid pgRNA accumulates
in cytoplasm Next, we investigated gene expression levels
of RLRs-mediated innate immune signaling in HBV-infected
PHHs under CAM treatment Gene expression levels of
intracellular immunity did not change with CAM monotherapy
On the other hand, IFNα upregulated gene expressions of
part of the innate immune signaling in HBV-infected PHHs
and CAM treatment enhanced the IFN-induced upregulation
of gene expressions Combination therapy with CAM and
IFNα significantly decreased HBsAg and HBeAg levels in
the supernatant and intracellular HBV DNA levels of HBVinfected
PHHs compared with CAM or IFNα monotherapy.
Finally, intrahepatic gene expression levels were analyzed
after HBV-infected human liver chimeric mice were treated
with CAM and/or IFNα for two weeks. CAM monotherapy
did not change gene expression levels of RLRs-mediated
innate immune signaling On the other hand, CAM treatment
in combination with IFNα upregulated gene expression levels
of RIG-I, MDA5 and other ISGs more strongly than IFNα
monotherapy Conclusion: Combination therapy with CAM
and IFNα activates innate immune response in HBV-infected
hepatocytes and could be a new therapeutic strategy against
HBV. 作者: StephenW 时间: 2019-10-24 13:52