PCB4233: Immunology

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PCB4233 Immunology

• Dr. Mauricio Rodriguez-Lanetty
• Email rodmauri_at_fiu.edu
• Phone [phone]
• Lecture 2

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Skin
Blood vessel
Special forces of high specialization
Troop (library) of soldiers (T/B cells)
Recognition Activation
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Skin
Blood vessel
Special forces of high specialization
Immunological memory
Troop (library) of soldiers (T/B cells)
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Skin
Blood vessel
Special forces of high specialization
Immunological memory
Troop (library) of soldiers (T/B cells)
How these special cells (T/B) does not attack
self cells in the body?
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Skin
Blood vessel
Special forces of high specialization
Immunological memory
Troop (library) of soldiers (T/B cells)
Factory of T/B Cells
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Skin
Blood vessel
Special forces of high specialization
Immunological memory
Troop (library) of soldiers (T/B cells)
Education Center for T-cells (Army Academy)
Education Center for B-cells (Army academy)
Factory of T/B Cells
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Skin
Blood vessel
Special forces of high specialization
Immunological memory
Troop (library) of soldiers (T/B cells)
Dont target/kill cells from your own body
Education Center for T-cells (Army Academy)
Education Center for B-cells (Army academy)
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Skin
Blood vessel
Special forces of high specialization
Immunological memory
Troop (library) of soldiers (T/B cells)
Education Center for T-cells (Army Academy)
Education Center for B-cells (Army academy)
Factory of T/B Cells
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Skin
Innate Immune System
Blood vessel
Adaptive Immune System
Special forces of high specialization
Immunological memory
Troop (library) of soldiers (T/B cells)
Education Center for T-cells (Army Academy)
Education Center for B-cells (Army academy)
Factory of T/B Cells
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Skin
Innate Immune System
Blood vessel
Adaptive Immune System
Special forces of high specialization
Secondary lymphoid organs
Immunological memory
Troop (library) of soldiers (T/B cells)
Primary / Central lymphoid organs
Education Center for T-cells (Army Academy)
Education Center for B-cells (Army academy)
Factory of T/B Cells
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Receptors with specificity for pathogens
molecules
Pattern Recognition Receptors (PRRs) This
receptors recognize repeating patterns of
molecular structure carried by microorganisms/path
ogens on their surfaces The pathogen-associated
molecular patterns that PRR recognize are called
PAMPs (MAMPs)
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The pathogen-associated molecular patterns that
PRR recognize are called PAMPs
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The Innate immune recognition by Toll-like
receptors (TLR)

• Toll-like receptors belong to an evolutionarily
  ancient recognition and signaling system
• Discovered from embryonic development studies in
  fruitfly
• Found to have a role in the defense against
  bacterial and fungal infections
• In Drosophila is Toll, and the homologous protein
  in mammals and other animals are therefore known
  as Toll-like receptors

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There are 10 expressed TLR genes in mice and
humans
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Infection stimulates macrophages to release
cytokines and chemokines that initiate an
inflammatory response
Chemokines function mainly as chemoattractants
for leukocytes, recruiting monocytes,
neutrophils, and other effector cells from the
blood to sites of infection
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Infection stimulates macrophages to release
cytokines and chemokines that initiate an
inflammatory response
The recruitment of activated phagocytes to sites
of infection is one of the most important
functions of innate immunity
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Important cytokines secreted by macrophages in
response to bacterial products
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Important cytokines secreted by macrophages in
response to bacterial products
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Chemokines can be produced by a wide variety of
cell types in response to bacterial products,
viruses, and agents that cause physical
damage. Thus, infection or physical damage to
tissues sets in motion the production of
chemokine gradients that can direct phagocytes to
the sites where they are needed.
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Neutrophils Normal adult releases1-3 x 1010
neutrophils per day from Bone Marrow Primary
function is phagocytosis and killing of
pathogens To do so neutrophils must gain
access to tissues from the bloodstream
extravasation Neutrophils are the first cells to
bind to inflamed tissue, and therefore to arrive
in large numbers at a site of infection, with
monocytes and immature dentritic cells being
recruited later.
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Neutrophils moving through the circulation
system ROLLING
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Neutrophils leave the blood and migrate to sites
of infection in a multi-step process
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Steps in neutrophil extravasation Rolling.
Recognition of inflamed tissue Activation by
chemoattractants Arrest and adhesion
Transendothelial migration Chemotaxis towards
source of infection
Same principles as for T cell migration in lymph
nodes
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Macrophages and neutrophils are not only brought
to potential sites of infection by chemokines but
in the process they are also armed to deal with
any pathogen they may encounter there. In
particular neutrophils exposed to CXCL8 and
cytokyne TNF-a are activated to produce the
respiratory burst that generates oxygen radicals,
nitric oxide, and to release their stored
lysosomal contents.
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Some differences between INNATE and ADAPTIVE
immunity
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That is all for today Thanks for coming!
Reading Material Chapter 1 and 2