studies

HEPATOLOGY, VOLUME 62, NUMBER 1 (SUPPL) AASLD ABSTRACTS 1243A
ity group box 1 (HMGB1) and soluble intercellular adhesion
molecule (sICAM)-1 was assessed in serum by enzyme-linked
immunosorbent assay (ELISA). Results In the WT mice, mortality
was 50 % at 24 hours after LPS/GalN injection. In contrast,
all KO mice survived at 24 hours after injection. There were
significant differences in the mortality between the WT mice
and the KO mice. However, in KO + rmIL-17A mice, mortality
was not significantly different compared to the other groups.
Neutrophil infiltration and apoptosis were significantly greater
in WT mice than KO mice. Furthermore, liver injury was severe
in the WT mice compared with the KO mice; however, in KO
+ rmIL-17A mice, injury was similar to those in the WT mice.
Serum ALT levels were also significantly greater in WT mice
than KO mice. In KO + rmIL-17A mice, these levels were similar
to those in WT mice, as expected. Supporting the pathological
findings, serum TNF-a, MCP-1, IL-17A, HMGB1 and sICAM-1
levels were also significantly greater in WT mice than KO mice.
In KO + rmIL-17A mice, these levels were similar to those in
WT mice. Conclusions IL-17A is a key regulator in hepatic
injury caused by neutrophil-induced inflammatory responses
after LPS/GalN injection. The lack of IL-17A decreases the
serum cytokine and chemokine levels, and all animals survived
after LPS/GalN treatment. These results suggest that IL-17A
may play one of the important role in fulminant hepatic injury.
Disclosures:
The following authors have nothing to disclose: Hiroshi Kono, Shinji Furuya,
Chao Sun, Hideki Fujii
2126
Upregulated hepatic expression of pattern recognition
receptors and Th1 type cytokine genes are associated
with clearance of HEV in genotype 1 infected rhesus
macaques
Youkyung Choi, Xiugen Zhang, Brianna Skinner, Chong-Gee Teo;
Center for Disease Control and Prevention, Atlanta, GA
Infection by hepatitis E virus (HEV) genotype 1 causes acute
liver disease that is usually self-limited but occasionally leads
to fulminant hepatic failure. Immune responses, rather than
virus-induced hepatocytolysis, have been shown to relate to
the pathogenesis of acute hepatitis E and liver failure. Since
HEV-specific CTL responses do not appear to be robustly
induced in peripheral blood of HEV-infected patients during the
acute and convalescent phases of infection, the liver is likely to
be the major site of pathogenically relevant anti-HEV immune
responses. In order to investigate the host immune responses
induced by HEV infection, host gene expression profiles were
analyzed in liver biopsy tissues of experimentally infected rhesus
macaques. Three rhesus macaques were inoculated with
HEV genotype 1 and observed for up to 150 days. All 3 exhibited
the course typical of acute hepatitis. Thus, HEV RNA was
detected in stools from 8 to 13 days after infection (DAI) and
in serum from DAIs 22 to 32, becoming undetectable between
DAIs 51 and 140; and elevated ALT activity and IgM and IgG
anti-HEV antibody became detectable between DAIs 39 and
56. Hepatic gene expression profiles were studied using 3 different
real-time PCR based rhesus-macaque-specific arrays (Qiagen)
that included 250 immune response-related genes. PCR
arrays were done at 3 time-points: during and after the peak
of stool HEV RNA detectability, and when HEV RNA became
undetectable. Levels of gene expression were compared to
normal liver tissues obtained from a macaque seronegative for
anti-HEV. Genes showing ≥2-fold change in expression were
considered to be significantly altered by HEV infection. Up to
57 genes were up-regulated during and after the peak of stool
HEV RNA detectability. These 57 genes could be grouped to
belong to 3 broad categories: pattern recognition receptors
(PRRs) (including TLR7 and TLR9); those associated with type 1
interferon response (including ISG15, ISG20, IRF1, IRF5 and
IRF7); and genes encoding Th1 type cytokines (including IL-12,
CCR5, CXCR3, IFNg, STAT4 and TBX21). Conclusions: Genes
upregulated in the liver during HEV infection include those
associated not only with type 1 interferon response and Th1
type cytokines but also PRRs. Upregulated hepatic PRR genes
possibly mediate heightened interferon response and cytokine
secretion, thereby contributing to resolution of acute infection.
Studies are ongoing to study the kinetics, in plasma, of proteins
associated with these responses.
Disclosures:
The following authors have nothing to disclose: Youkyung Choi, Xiugen Zhang,
Brianna Skinner, Chong-Gee Teo
2127
Hepatocellular carcinoma is accelerated by modified
western diet involving M2 macrophage polarization
mediated by HIF-1a activation
Aditya Ambade, Abhishek Satishchandran, Banishree Saha,
Karen Kodys, Gyongyi Szabo; Medicine, UMass Medical School,
Worcester, MA
Background/Aims: Obesity is an independent risk factor for
the development of hepatocellular carcinoma (HCC), the third
leading cause of cancer related deaths worldwide. Tissue resident
macrophages play a key role in promoting tumor progression.
Transformed cells within the tumor tissue can induce
macrophage polarization as a survival mechanism. However,
the effect of western diet on macrophage polarization in tumor
tissue microenvironment is not known. Here we sought to understand
the role of western diet in promoting tumor development
and inducing macrophage polarization after carcinogen
pre-exposure. Methods: Four week-old male C57BL/6 mice
were injected with 6 doses of N, N diethyl nitrosamine (DEN)
intraperitoneally. 75 mg/kg/week DEN was administered for
3 weeks followed by 100 mg/kg/week for 3 weeks. At 6
weeks of age, mice were divided into modified western diet
containing high fat-high cholesterol-high sugar (HF-HC-HS)
and chow (control) diet groups. All mice were sacrificed at
30 weeks of age; blood, liver, primary hepatocytes and liver
mononuclear cells (LMNCs) were collected. In vitro, naïve primary
hepatocytes were treated with 10 mM DEN and/or 330
mM palmitic acid (PA) and supernatants were transferred to
RAW 264.7 macrophages. Results: HF-HC-HS diet resulted
in weight gain except for mice with DEN injection. ALT and
liver to body weight ratio were significantly higher in HF-HC-
HS+DEN compared to HF-HC-HS diet mice. Serum AFP levels
were significantly higher in HF-HC-HS+DEN mice compared to
all other groups (P