studies

HEPATOLOGY, VOLUME 62, NUMBER 1 (SUPPL) AASLD ABSTRACTS 1245A
2130
Allogeneic and xenogeneic transplantation of primary
hepatocytes into the fetal liver in mice
Yoshinobu Saito, Hayato Hikita, Yasutoshi Nozaki, Yugo Kai, Yuki
Makino, Tasuku Nakabori, Satoshi Tanaka, Satoshi Aono, Ryotaro
Sakamori, Naoki Hiramatsu, Tomohide Tatsumi, Tetsuo Takehara;
Gastroenterology and Hepatology, Osaka University Graduate
School of Medicine, Suita, Japan
Background and Aim: Liver humanized mouse models using
Alb-uPA SCID mice and Alb-HSVtk NOG mice have been
reported to provide a lot of information on human liver physiology
and pathology. However, these mouse models are not
appropriate for investigating chronic inflammation and liver
cancer because these mice are immune-deficient and could not
survive more than one year. Immune tolerance is considered
to be established during embryonic or neonatal stage. In this
study, we investigated the engraftment efficacy of allogeneic or
xenogeneic hepatocytes into the fetal liver by in utero transplantation
in immune-competent mice. Method: As immune-competent
recipient mice, we used hepatocyte-specific Mcl-1 knockout
(KO) mice, which cause spontaneous hepatocyte apoptosis
in life (Liver Injury mice), and hepatocyte-specific Mcl-1 and
Bcl-xL double KO (DKO) mice, which show a decreased number
of hepatocytes on embryonic (E) 18.5 day and die within
one day after birth due to hepatic failure (Liver Impairment
mice). Primary hepatocytes isolated from ubiquitously green fluorescent
protein (GFP) transgenic (Tg) mice or primary human
hepatocytes were administered into these recipient mice on E
16.5 day via vitelline vein. These embryos were given birth by
cesarean section and these livers were investigated at birth or
at the age of 6 weeks. Results: Hepatocyte-transplanted wildtype
mice and Liver Injury mice showed scattered embolization
areas at birth by HE staining of the liver sections. The embolization
was considered to be caused by transplanted hepatocytes.
In contrast, Liver Impairment mouse livers escaped from
embolization. In livers of wild-type mice and Liver Injury mice
transplanted with GFP Tg hepatocytes, GFP-positive cells were
observed forming a lot of clusters. While repopulation rate was
not different between livers of wild-type mice and those of Liver
Injury mice at birth (35.8% (3.6-48.3) and 29.8% (20.4-39.1),
respectively), that of Liver Impairment was 7.8% (3.3-16.7).
Meanwhile, repopulation rate at the age of 6 weeks was 0% in
wild-type mice and 4.2% (2.1-8.0) in Liver Injury mice. In livers
of wild-type and Liver Injury mice transplanted with primary
human hepatocytes, embolization was similarly observed at
birth by HE staining, suggesting that transplanted hepatocytes
might be engrafted. Conclusion: Our results suggests that transplantation
of primary hepatocytes into the fetal liver of Liver
Injury mice, but not Liver Impairment mice, have the possibility
of generating humanized liver mice without immunodeficiency.
Disclosures:
Hayato Hikita - Grant/Research Support: Bristol-Myers Squibb
Tetsuo Takehara - Grant/Research Support: Chugai Pharmaceutical Co., MSD
K.K., Bristol-Meyer Squibb, Mitsubishi Tanabe Pharma Corparation, Toray Industories
Inc. ; Speaking and Teaching: MSD K.K., Bristol-Meyer Squibb, Janssen
Pharmaceutical Companies
The following authors have nothing to disclose: Yoshinobu Saito, Yasutoshi
Nozaki, Yugo Kai, Yuki Makino, Tasuku Nakabori, Satoshi Tanaka, Satoshi
Aono, Ryotaro Sakamori, Naoki Hiramatsu, Tomohide Tatsumi
2131
The gut-liver axis coordinate T-cell-mediated immunity
by regulating the antigen-presenting activity of macrophages
in murine liver
Nobuhito Taniki 1 , Nobuhiro Nakamoto 1 , Hirotoshi Ebinuma 1 ,
Po-sung Chu 1 , Takeru Amiya 1 , Shunsuke Shiba 1 , Akihiro Yamaguchi
1 , Yuko Wakayama 1 , Hidetsugu Saito 2 , Takanori Kanai 1 ;
1 Internal Medicine, Keio University, School Of Medicine, Tokyo,
Japan; 2 Pharmaceutical Department, Keio University, Tokyo, Japan
BACKGROUND & AIMS: The liver is a barrier for gut-derived
antigens from degraded commensal bacteria. In colitic mice,
live bacteria escaping the gut enter the liver through the portal
vein. Specific subsets of innate immune cells suppress immune
responses to such gut-derived antigens. The hygiene hypothesis
proposes the recent increase in autoimmune hepatitis is the
result of modern highly hygienic lifestyles. Reduced antigen
exposure may cause dysfunctional hepatic immunosuppressive
mechanisms. We hypothesized that increased antigen stimuli
might activate immunosuppression. We investigated the role of
innate immune cells in immunological tolerance in murine liver
and the underlying mechanisms, focusing on the gut-liver axis.
METHODS: We reported that dextran sulfate sodium (DSS)-
treated mice (a colitis model) developed mild liver inflammation
by histology and serology compared with normal mice following
a sub-lethal dose of concanavalin A (ConA) (a T-cell-mediated
hepatitis model). Colitis severity was inversely correlated
with subsequent liver inflammation. We analyzed immune cell
subsets in organs from experimental groups (WATER pre-ConA,
WATER-ConA, DSS-pre ConA, and DSS-ConA). RESULTS: In
DSS-ConA mouse liver, numbers of CD4 + and CD8 + T cells
were decreased significantly, compared with the WATER-ConA
group, but numbers of Foxp3 + CD4 + regulatory T cells (Tregs)
were unchanged. Importantly, gene expression of the inflammatory
cytokines interferon-gamma (IFN-γ) and tumor necrosis
factor (TNF) in sorted T cells were significantly decreased in the
DSS-ConA group. We recently reported that TNF-producing
CCR9 + CD11b + macrophages were critical in the pathogenesis
of ConA-induced acute liver injury by inducing T helper
1 responses. In WATER-ConA-treated livers, CCR9 + CD11b +
macrophages (WATER-ConA mac) were increased and CCR9 -
CD11b + macrophages (DSS-ConA mac), a functionally distinct
subset from WATER-ConA mac, were increased in DSS-ConAtreated
livers. Sorted DSS-ConA mac had regulatory characteristics
and produced IL-10, but low levels of TNF or IFN-γ after
LPS stimulation in vitro. DSS-ConA mac expressed low MHC
class II and CD80, and antigen presentation to naïve CD4 T
cells derived from ovalbumin-specific αβ-TCR transgenic mice
was deficient. CONCLUSIONS: CCR9 - CD11b + macrophages
migrate to the inflamed liver under a colitic state and contribute
to immunological tolerance in the liver by suppressing T-cell
immunity. Our data provide a novel mechanism underlying
immune tolerance in the liver through the gut-liver axis.
Disclosures:
Takanori Kanai - Grant/Research Support: Mitsubishi Tanabe Pharma Corporation
The following authors have nothing to disclose: Nobuhito Taniki, Nobuhiro Nakamoto,
Hirotoshi Ebinuma, Po-sung Chu, Takeru Amiya, Shunsuke Shiba, Akihiro
Yamaguchi, Yuko Wakayama, Hidetsugu Saito