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Hello, my name is Kelly Bruton,
I'm a postdoctoral fellow at
Stanford University
and today I'll
be discussing immune memory
underlying lifelong
peanut allergies.
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To begin what our
food allergies?
Food allergies are
broadly considered as
any adverse reaction to an
innocuous food protein.
Classically, food allergies
are considered to
be a type one
hypersensitivity reactions,
meaning that the effector
mechanisms are mediated by
IgE or immunoglobulin E.
When IgE is produced,
it binds to high
affinity receptors
on mast cells and basophils,
essentially coding
the cells with
allergen-specific IgE and
maintaining the cells in a
primed or sensitized
state ready to
rapidly react upon
allergen exposure.
Upon this allergen exposure,
allergen cross-links cell
bound IgE molecules,
triggering an intracellular
signaling cascade
and rapid degranulation.
Release of these
preformed mediators,
such as histamine and
platelet activating factor,
are what ultimately issue
the clinical manifestations
of an allergic response.
These reactions can range in
severity from something mild
such as urticaria to
severe life-threatening
anaphylaxis.
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The immune response to
a food allergy and can
be grouped into three
distinct phases.
Firstly, allergic
sensitization occurs
upon an individual's first
exposure to an allergen
and the mechanisms through which
allergic sensitization occur
are incompletely defined.
Though the product of this
process is the generation of
IgE specific to the
insulting allergen.
As previously mentioned,
this IgE then coats
the surface of
mast cells and basophils through
the high affinity IgE receptor.
The second phase is reactivity.
After sensitisation,
subsequent allergen
exposure cross-link cell
bound IgE causing
an acute release
of vasoactive mediators.
The third phase and the area
in which today's talk will
focus is persistence of
this pathogenic response
toward allergens.
Allergies to food such as egg,
and milk are typically outgrown
within the first
few years of life.
In contrast,
allergies to peanuts,
tree nuts and shellfish,
and can persist for a lifetime.
For this reason, it's been a
particular interest to study
the immunological
mechanisms that
facilitate the maintenance
of lifelong food allergies.
