0:00
Hi. My name's Kevin Maloy.
I'm a lecturer in
Experimental Pathology at
the Sir William Dunn
School of Pathology
at the University of Oxford.
My lab has a long-standing
interest in mucosal immunology,
with a particular focus on
the regulation of innate
immunity in the intestine,
which is the subject
of this lecture.
My group is interested in
how different types of
innate immune
receptors contribute
to protection from infection,
but also to immune pathology
and allergen testing.
I'll use some examples from
our research to illustrate
some recent advances in the innate
immune pathways in the intestine.
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I will briefly describe some of
the key features of
intestinal immunity,
including some of the
unique characteristics that
differentiate the
intestinal immune system
from the systemic immune system.
I'll then outline
the key functions
of intestinal epithelial cells,
which are an integral part of
innate immune
defense in the gut,
by maintaining an
effective barrier function
and by producing
protective immune factors.
I will also consider
how intestinal microbes
are detected by the innate
immune system through
pattern recognition
receptors (PPRs),
and how these interactions
can regulate intestinal
homeostasis.
I will outline recent
findings on the types
and functions of innate
leukocytes in the gut.
In the second part
of the lecture,
I will discuss how dysregulation
of innate immunity in
the gut is associated with
inflammatory bowel disease.
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Most of what we know about how
the immune system works has been
derived from extensive study
of systemic immune responses,
which are elicited in the
peripheral lymphoid tissues,
such as the lymph
nodes and spleen.
However, most pathogens
invade the body at interfaces
between the host and
external environment,
such as in mucosal surfaces.
These are internal
body surfaces lined
by a thin layer of
mucus-secreting epithelium,
such as the
gastrointestinal tract,
the respiratory tract and
the urogenital tract.
These surfaces constitute
a huge surface area.
Therefore, the
mucosal immune system
is the largest immune
compartment in the body.
It contains 75 percent
of all lymphocytes
and produces the
majority of antibodies.
The mucosal immune system
presents the first line of defense
against invading pathogens,
and also provides protection
against reinfection
by previously
encountered pathogens.
