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0:00
Hello. My name is Kelly Bruton.
I'm a postdoctoral fellow
at Stanford University.
My research is centered
around studying
adaptive immune
responses involved
in IgE mediated allergies,
particularly looking
at the ontogeny and
function of allergen-specific
memory B cells.
In today's talk,
I'll be talking about the role
and the presence of memory
B cells in allergy.
0:24
In today's talk, I'll start with
a brief and broad overview of
the primary B cell response,
the resulting B cell
effector functions
and how the ensuing
establishment of
B cell immune memory and
the heterogeneity in
B cell memory that has
recently been uncovered.
Processes like class-switched
re-combination and
affinity maturation will
be mentioned in this talk.
But the mechanism through which
these occur should be
reviewed elsewhere.
In Part 2, I'll focus on the
role of B cells in allergy.
I'll discuss our understanding
of the functional profile of
allergen-specific memory B
cells, whether these cells
irreversibly commit
to an IgE fate, and
potential future directions to
harness memory B cell plasticity
in the treatment of
long-lived allergies.
1:11
To begin with naïve
B cell activation,
antigen is transported
from the periphery.
The site of infection,
for example,
to the draining lymph
nodes, and this
initiates the process of
naïve B cell activation.
Antigen can be
transported possibly to
secondary lymphoid organs,
such as lymph nodes through
both blood and
lymph, and can also
be actively transported
to these sites by
antigen presenting cells
that have engulfed or
phagocytosed the antigen
at a peripheral site.
The lymph node is a highly
organized structure
containing an outer
capsule, then a cortex,
paracortex, and the
innermost region
referred to as the medulla.
Between the capsule and the
cortex is a subcapsular space
which sees the lymph fluid that
enters through the afferent
lymphatic vessels.
Within this space, you can find
subcapsular sinus macrophages
that are able to efficiently
capture antigen from
the draining lymph
fluid and translocate
this antigen to the
neighboring cortex region
which houses B cell follicles.
Here, B cells can then acquire
antigen immune complexes
from subcapsular macrophages
in a complement
dependent manner,
and transport the antigen to
follicular dendritic cells
which are residing in
the B cell follicles
and they're able to
stably retain this
antigen long term.
Once antigen is present
within lymph nodes,
cognate B cells can
interact with the
native antigen through
their B cell receptor,
and this initiates
a cascade of downstream events
necessary for full activation.
Upon recognizing the antigen,
these B cells become activated
triggering a cascade
of immune responses.
This will lead to the
proliferation and
differentiation of these
cells into effector cells,
which are capable of producing
mass amounts of antibodies
that will specifically target
the insulting antigen.
