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Ian Nicholas Crispe,
M.D., Ph. D.
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Member
Seattle Biomedical Research Institute
Email:
nick.crispe@sbri.org
Diseases under study:
viral hepatitis, gene therapy,
malaria
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Mission
The mission of the Crispe lab is to dissect and
understand the ways in which the immune system
responds to antigens, virus vectors and
parasites in the liver. The immune system works
differently in the liver, partly because this
organ must receive food components, together
with molecules synthesized by the large
bacterial population that lives in the normal
intestine. As a consequence of this continuous
stream of foreign molecules, the liver’s innate
and adaptive immune systems have a unique
configuration, where the threshold for launching
an immune response is higher. This adaptation
creates a window of opportunity, which is
exploited by well-adapted pathogens including
malaria parasites. Therefore, we will reveal the
mechanisms by which the liver stage of malaria
evades immunity, and how the emerging
experimental vaccine strategies provide
protection. This knowledge will strengthen
efforts to make a universally-available malaria
vaccine that eliminates the parasite at the
liver stage, before it infects red blood cells
and causes disease.
Research
We work on the basic biology of immune
responses, with a focus on responses in the
liver. Therefore, we have used bone marrow
transplantation and experimental liver
transplantation to reveal the unique
immunological functions of the liver, and
the relative roles of leukocytes derived
from the bone marrow, versus fixed
tissue-resident cells. The liver contains a
large population of macrophages, named
Kupffer cells. While most macrophages are
located in tissues, the Kupffer cells are
unusual since they reside in the blood
space; they therefore act as a filter,
removing foreign matter from the blood. We
investigate the origin and biological
function of these cells, in particular their
functions as regulators of natural killer
cell activation, and as participants in
immunological damage to the liver. These
studies reveal a complex network of immune
cross-talk which is disrupted during
infections of the liver, such as hepatitis B
and hepatitis C.
The outstanding research environment of the
SBRI allows us to extend our study of liver
immunology to address the malaria parasite.
In particular, how does this parasite avoid
immune elimination during its essential
stage of maturation inside liver cells, and
how could we generate such immunity? We are
therefore launching a collaboration with Dr
Stefan Kappe to dissect the mechanism by
which genetically-modified malaria parasites
cause sterilizing immunity. We will
determine how and where the malaria antigens
are presented to the T cell system, which T
cells are activated, and how they deliver
protection. The biological insights from
these studies will define “protective
immunity” more precisely, so that human
vaccine trials may look for the same
modalities of immunity.
Themes
* Antigen presentation by liver-resident cells,
including hepatocytes
* The activation and fate of liver-primed T cells
* The mechanism by which the immune system eliminates
antigenic liver cells
* The role of Kupffer cells in regulating immunity and
liver injury
* Liver immunopathology initiated by T cells
* Immune subversion by hepatitis viruses and malaria
parasites
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Accomplishments |
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Showed
that the liver is an important site for T cell
destruction |
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Identified
mechanisms by which circulating activated T cells stick in the liver, and
linked this to endotoxin from the intestinal bacteria. |
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showed that the
liver itself can activate T cells |
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pinpointed the
Kupffer cell as a key regulator of innate immunity |
The National Institute of Allergy &
Infectious Diseases and the National
Institute of Diabetes and Digestive and
Kidney Diseases currently provide support for Dr. Crispe’s research.
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