Lecture-12 B-Cell Development and differentiation

The development of B cells involved in adaptive immunity and their embryonic and adult germinating sites are shown.
The clonal selection theory as proposed by Niles Jerne depicting the proliferation of activated B lymphocytes to participate in the adaptive immunity will be appreciated.

1. Prof. Sreerama Krupanidhi
Email: [email protected]

2. 1.To familiarize with B cells
2.To acquaint with the sites of B-cells
origin
3.To appreciate the clonal selection
theory
4.To know the maturation of B cells
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3. 1.The development of B cells involved in
adaptive immunity and their
embryonic and adult germinating sites
will be known.
2.The clonal selection theory depicting
the proliferation of activated B
lymphocytes to participate in the
adaptive immunity will be appreciated.
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4. Blood cell precursors originate in
yolk sac and liver
In postnatal life the stem cells
reside in the bone marrow
Stem cells differentiate into cells of
erythroid, myeloid or lymphoid
series
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7. Origin
During embryogenesis – fetal liver
Migrate to bone marrow – final
destination
Maturation of B cells involves two
phases:
Antigen independent phase consists of stem
cells, pre-B cells and B cells
Antigen dependent phase consists of
activated B cells and plasma cells
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8. Memory B- cell Development
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21. B cells display surface IgM which
serves as an antigen receptor
Surface IgD on some B cells also serves
as an antigen receptor
Pre B cells are found in bone marrow
and mature B cells are found
circulating lymph nodes and blood
stream
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22. B cells constitute about 30% of
circulating small lymphocyte
Their life span is short ie, days or
weeks
Location: lymph nodes – germinal
centers, spleen – white pulp and
Peyer’s patches
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23. Clonal selection
Antigen reacts with surface IgM and
IgD on the best fit basis
After antigen binds, B cell is stimulated
to proliferate to form a clone of cells
These selected B cells later
differentiate into antibody producing
plasma cells that secrete antibody
specific to that antigen.
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24. 1955: Jerne, Burnet, Talmage (Nobel Prize)
Lymphocytes arise from clones, each
clone arises from a single primed cell
producing a single Ab specificity
When an antigen enters the body, it binds a
clone of cells and this clone produces Ab
specific to that antigen: Clonal Selection
Theory
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31. 1.Blood cell precursors originate in yolk sac
and liver and transform to bone marrow
during postnatal life.
2.B-cells display IgM followed by IgD. They
mature in bone marrow and circulate in
Blood.
3.Activated B- cells undergo clonal selection.
4. IL-4 and IL-5 (B-cell) promote Lymphocyte
proliferation.
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32. Elaborate the differentiation of B Cell
developmemnt.
Where from the name B came for B Cells?
Explain class switch in B cell
development.
Indicate the Igs gradually added to
developing B cell.
Elaborate on B cell differentiation.
What is the attribute of B cell?
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33. We acknowledge online
resources/public domains for
the use of the content to develop
teaching material and for the
dissemination of knowledge.
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