studies

692A AASLD ABSTRACTS HEPATOLOGY, October, 2015
The following authors have nothing to disclose: Donatella Palazzo, Elisa Biliotti,
Francesca Tinti, Alessandra Bachetoni, Stefania Grieco, Andrea Cappoli, Raffaella
Labriola, Paola Perinelli, Ilaria Umbro, Paola Rucci, Anna Paola Mitterhofer
984
Hepatitis C virus facilitates its persistent infection
through ΔNp63-miR-181a-SIRT1/ DUSP6 signaling
pathways
Yun Zhou 1,2 , Guangyu Li 2,3 , Junping Ren 2,3 , Ying Zhang 1 , Jianqi
Lian 1 , Changxing Huang 1 , Shunbin Ning 2,3 , Jonathan P. Moorman
2,3 , Zhansheng Jia 1 , Zhi Q. Yao 2,3 ; 1 Department of Infectious
Diseases, Tangdu Hospital, Fourth Military Medical University,
Xi’an, China; 2 Department of Internal Medicine, Division of Infectious
Diseases, James H. Quillen College of Medicine, East Tennessee
State University, Johnson City, TN; 3 Center for Inflammation,
Infectious Disease and Immunity, James H. Quillen College of Medicine,
East Tennessee State University, Johnson city, TN
T cells play a crucial role for viral clearance or persistence;
however, the precise mechanisms that control their responses
during viral infection remain largely unknown. MicroRNAs
(miR) have been implicated as key regulators controlling
diverse biological processes through posttranscriptional repression.
Here we demonstrate that hepatitis C virus (HCV)-mediated
regulation of ΔNp63 and miR-181a expression impairs
CD4+ T cell responses to facilitate viral persistence via the
dual specific phosphatase 6 (DUSP6) and SIRT1 signaling pathways.
Specifically, a significant up-regulation of ΔNp63 leads
to a decline of miR-181a expression, concomitant with over-expression
of DUSP6 and SIRT1 in CD4+ T cells from chronically
HCV-infected individuals compared to healthy subjects.
The levels of ΔNp63 expression were found to be negatively
associated with the levels of miR-181a, which in turn correlate
to the expressions of DUSP6 and SIRT1 in these cells. Importantly,
silencing ΔNp63/SIRT1 or reconstitution of miR-181a
expression in CD4+ T cells leads to T cell senescence including
reduced telomerase activity, shortened telomere length,
increased senescence-associated β-galactosidaese (SA-β-gal)
expression, and decreased EdU incorporation. Paradoxically,
an increased IL-2 expression is observed in CD4+ T cells by
these treatments, primarily due to a reduced frequencies of
Foxp3+ regulatory T cells (Tregs) and increased or unchanged
numbers of Foxp3- effector T cells (Teffs) along with manipulating
the ΔNp63-miR181a-Sirt1 pathway. These findings provide
novel mechanistic insights into how HCV induces T cell exhaustion
via ΔNp63-miR-181a-DUSP6 signaling and premature T
cell aging via ΔNp63-miR-181a-SIRT1 pathway. These two
major pathways reveal new targets for therapeutic rejuvenation
of impaired T cell responses during chronic viral infection.
Disclosures:
The following authors have nothing to disclose: Yun Zhou, Guangyu Li, Junping
Ren, Ying Zhang, Jianqi Lian, Changxing Huang, Shunbin Ning, Jonathan P.
Moorman, Zhansheng Jia, Zhi Q. Yao
985
Effects of Resistance Mutations of NS5A Inhibitor
on Viral Production and Susceptibility to Anti-HCV
Reagents in Recombinant Hepatitis C Viruses with NS5A
of Genotype 1b
Sayuri Nitta 1,2 , Yasuhiro Asahina 1 , Takaji Wakita 2 , Takanobu
Kato 2 ; 1 Gastroenterology and Hepatology, Tokyo Medical and
Dental University, Tokyo, Japan; 2 Virology II, National Institute of
Infectious Diseases, Tokyo, Japan
Backgrounds and Aims: The direct acting antiviral agents
(DAAs) for hepatitis C virus (HCV) have strong inhibitory
potency to HCV. However, using DAAs could cause the emergence
of resistance mutations because these agents directly target
HCV proteins. Amino acid substitutions at L31 and Y93 of
non-structural protein 5A (NS5A) in HCV genotype 1b strains
have been reported to confer resistance to NS5A inhibitor,
daclatasvir (DCV). Furthermore, strains with these mutations
are often detected in DCV treatment naïve patients. In this
study, we assessed the effects of resistance mutations of DCV
on HCV life cycle and susceptibility to DCV and other anti-HCV
reagents by use of recombinant HCV harboring NS5A of genotype
1b strain, Con1. Materials and Methods: We constructed
recombinant HCV harboring NS5A of Con1 (JFH1-5ACon1),
and introduced reported DCV resistance mutations, L31M,
L31V, L31I and Y93H, in solely or in combination. In vitro transcribed
full-length HCV RNA of these strains were transfected
into Huh-7.5.1 cells and evaluated HCV replication and infections
virus production by measuring the extra- and intra-cellular
HCV core antigen (Ag) and infectivity titers. Susceptibilities of
these strains to various anti-HCV reagents were also investigated.
Results: All these strains are capable of replication in
Huh-7.5.1 cells. At day 3 post-transfection, intra-cellular HCV
core Ag levels were comparable in these strains transfected
cells. However, extra-cellular HCV core Ag levels of strains with
Y93H were about 2-fold higher than that of JFH-1/5ACon1.
To assess the affecting step of this mutation in HCV life cycle,
we determined the infectivity titers of these recombinant HCV.
The strains with Y93H indicated higher infectivity titers than
that of JFH-1/5ACon1. In the analysis of susceptibility to DCV,
strains with mutation at L31 or Y93 showed the relatively mild
or moderate resistance, while those with mutations at both L31
and Y93 showed severe resistance, consistent with previous
reports. Strains with DCV resistance mutations exhibited similar
level susceptibility to IFNα, IFNλ1, IFNλ3 or RBV. Interestingly,
the strains with Y93H mutation were more sensitive to protease
inhibitor simeprevir (SMV) in comparison with JFH-1/5ACon1.
Conclusions:In the in vitro study with recombinant HCV with
NS5A of Con1, we indicated that the strains with Y93H
enhanced infectious virus production. This observation suggests
that once strains with Y93H emerged, it might be persistent
after treatment. From our findings in susceptibility analysis to
SMV, regimen including SMV could be considerable to treat
the patients infected HCV with Y93H mutation.
Disclosures:
The following authors have nothing to disclose: Sayuri Nitta, Yasuhiro Asahina,
Takaji Wakita, Takanobu Kato
986
The impact of HLA-DQs and IFNL4 variant on hepatitis C
virus-induced liver inflammation
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 Hospital, Hiroshima, Japan
Background & Aims: Several previous studies including genomewide
association studies (GWAS) revealed that genetic variation
in the IFNL3 (IL28B)-IFNL4 locus and the MHC region were
associated not only with hepatitis C virus (HCV) persistence
but also with HCV-induced cirrhosis and hepatocellular carcinoma.
Because these variants appear to be associated with
the progression of chronic HCV infection, they might play an