studies

1012A AASLD ABSTRACTS HEPATOLOGY, October, 2015
B, where the liver damage is T-cell mediated, our data suggest
that a unique type of humoral immunity against HBcAg plays a
primary role in the pathogenesis of HBV-ALF.
Disclosures:
The following authors have nothing to disclose: Zhaochun Chen, Huaying Zhao,
Peter Schuck, Ronald E. Engle, Fausto Zamboni, Giacomo Diaz, David E. Kleiner,
Robert H. Purcell, Patrizia Farci
1647
The expansion of CD11b - CD27 - NK-cell subset contributes
to HBV persistence via TGF-β1
Qiongfang Zhang 1,2 , Wenwei Yin 1,2 , Jian-ying Shao 1,2 , Qian
Liu 1,2 , Peng Hu 1,2 , Huaidong Hu 1,2 , Hong Ren 1,2 , Dazhi Zhang 1,2 ;
1 The institute of viral hepatitis,Department of infectiouse diseases,
Chongqing Medical University, Chongqing, China; 2 The Second
Affiliated Hospital of Chongqing Medical University, Chong qing,
China
Background /purposeThe mechanism underlying persistent
hepatitis B virus (HBV) infection remains unclear. Natural killer
(NK) cells, as a major component of the antiviral immune
response, has been reported to alter their distribution of NK-cell
subsets. We reported a novel mechanism associated with viral
persistence from NK cell-mediated antiviral immunity in patients
in immune tolerant (IT) phase. Method We investigated the
role of NK subsets to persistent HBV infection in 109 chronic
hepatitis B (CHB) patients and 38 healthy controls (HC) by flow
cytometry. Serum cytokine concentrations were analyzed using
a Cytometric Bead Array (CBA) Inflammation Kit and a standard
sandwich enzyme-linked immunosorbent assay (ELISA)
Kit. Result We found a substantial CD11b - CD27 - (DN) NK-cell
population harboured in patients in IT phase compared with
patients in immune active (IA) phase, patients in immune inactive
(IN) phase and HC. And there existed a positive correlation
between the expanding DN NK-cell subtype and HBV-DNA
load. This DN NK subset displayed an immature and inactive
phenotype and showed poor degranulation and IFN-γproduction.
Higher concentrations of transforming growth factor beta1
(TGF-β1) were found in sera from IT-phase patients, which positively
correlated with HBV-DNA load. In vitro, TGF-β1 up-regulated
the presence of DN NK-cell population. Moreoverthe,
percentage of DN NK-cell subset in fresh NK cells preincubated
with sera from IT patients was markedly higher compared with
IA phase patients, IN phase patients and HC. Anti-TGF-β1 antibodies
could partially restore the altered NK-cell subsets. Conclusion
Our findings demonstrated that the IT microenvironment
may render circulating NK cells into an inefficient subtype by
up-regulating the levels of TGF-β1 in serum, which was correlated
with persistent HBV infection.
Disclosures:
The following authors have nothing to disclose: Qiongfang Zhang, Wenwei Yin,
Jian-ying Shao, Qian Liu, Peng Hu, Huaidong Hu, Hong Ren, Dazhi Zhang
1648
Comprehensive analysis of the Rab family to screen
membrane traffic pathways utilized by hepatitis B virus
Jun Inoue, Yasuteru Kondo, Teruyuki Umetsu, Takuya Nakamura,
Takayuki Kogure, Yu Nakagome, Yuta Wakui, Tatsuki Morosawa,
Yasuyuki Fujisaka, Satoshi Takai, Tooru Shimosegawa; Division
of Gastroenterology, Tohoku University Graduate School of Medicine,
Sendai, Japan
Background/aim: The trafficking pathways of hepatitis B virus
(HBV) components in the host cells have remained largely
unknown. Previously, we showed that the small GTPase Rab7
regulates HBV secretion from multivesicular bodies (MVBs)
by facilitating viral degradation by lysosomes (Inoue at al.,
J Cell Sci 2015). It is thought that the HBV core particles are
enveloped in MVBs, but the transport pathway of the envelope
HBs proteins to MVBs has not been determined. In this study,
we performed a comprehensive screening of Rab proteins to
identify important pathways in the assembly/release of HBV.
Methods: Using HepG2.2.15 cells stably expressing HBV, 61
Rab proteins were depleted separately with siRNA-mediated
knockdown. With an siRNA concentration that maintained cell
viability of more than 80%, HBV DNA and HBsAg in the culture
supernatant were quantified 3 days after siRNA transfection.
Results: The effects of Rab knockdown were divided into 7
groups as follows: 1) decreased HBV DNA, 2) increased HBV
DNA, 3) decreased HBsAg, 4) increased HBsAg, 5) decreased
both HBV DNA and HBsAg, 6) increased both HBV DNA and
HBsAg, 7) increased HBV DNA but decreased HBsAg. Group
5 Rab proteins, which were considered to play roles in the
assembly/release of both HBsAg subviral particles (SVPs)
and HBV particles included Rab8, Rab13, and Rab38. These
were reported to be associated with the vesicle transport from
Golgi. Interestingly, the depletion of Rab5B, which is one of
three isotypes of Rab5 and is known to be associated with
early endosomes, increased both HBV DNA and HBsAg. The
Rab5B depletion increased HBV DNA significantly more than
the depletion of other Rab5 isotypes and the effect was rescued
by the expression of GFP-Rab5B. Sucrose density gradient centrifugation
revealed that the density of increased HBV particles
after the Rab5B depletion was lowered from 1.24 g/ml to
1.17-1.19 g/ml. These data indicate that Rab5B depletion
may increase the release of immature HBV particles whose
envelope components are altered. The significance of Golgi-related
Rab proteins and Rab5B in early endosomes for the
formation of mature HBV particles suggests the presence of a
novel HBV life cycle pathway: HBs proteins are transported to
the cellular membrane once via Golgi, and are endocytosed to
early endosomes and late endosomes/MVBs, where the HBV
core particles are thought to be enveloped. Conclusion: The
findings of the Rab family screening suggested the importance
of both the Golgi-related pathway and endocytotic pathway in
the formation of mature HBV particles. This is a novel concept
in the HBV life cycle and these steps could become targets of
antiviral therapies.
Disclosures:
The following authors have nothing to disclose: Jun Inoue, Yasuteru Kondo,
Teruyuki Umetsu, Takuya Nakamura, Takayuki Kogure, Yu Nakagome, Yuta
Wakui, Tatsuki Morosawa, Yasuyuki Fujisaka, Satoshi Takai, Tooru Shimosegawa
1649
Genome-wide scan of miRNA polymorphisms revealed
a suggestive association of miR-3143 with chronic hepatitis
B virus infection
Daiki Miki 1,2 , Hidenori Ochi 1,2 , C. Nelson Hayes 1,2 , Hiromi Abe 1,2 ,
Sakura Akamatsu 1,2 , Atsushi Ono 1,2 , Takashi Nakahara 1,2 , Yizhou
Zhang 1,2 , Keiichi Masaki 1,2 , Hatsue Fujino 1,2 , Eisuke Miyaki 1,2 ,
Hiromi Kan 1,2 , Takuro Uchida 1,2 , Nobuhiko Hiraga 1,2 , Masataka
Tsuge 1,2 , Tomokazu Kawaoka 1,2 , Michio Imamura 1,2 , Yoshiiku
Kawakami 1,2 , Hiroshi Aikata 1,2 , Kazuaki Chayama 1,2 ; 1 Laboratory
for Digestive Diseases, RIKEN Center for Integrative Medical
Sciences, Hiroshima, Japan; 2 Department of Gastroenterology and
Metabolism, Hiroshima University Hostital, Hiroshima, Japan
Background & Aims: Recent genome-wide association studies
(GWAS) have revealed several host genetic factors associated
with various liver diseases, but the majority of genetic factors
remain unclear. MicroRNAs (miRNAs) are small non-coding
RNAs that control gene expression post-transcriptionally and