Basic Immunology: Nuts and Bolts of the Immune System
Anthony DeFranco (1:28:41)
For Exam 3 (Chap. 16) - only the first 30 minutes. The rest will be covered with Chap. 17.
YouTube Assignment: Go to YouTube online. Type “Basic Immunology: Nuts and Bolts of the
Immune System” in the Search box to obtain the above YouTube video. See outline next page.
I.
Text: Chap. 16 The Innate Immune System
a. Innate Immunity vs. Adaptive Immunity
Fig. 16.1
b. Basic terms: TLRs, PAMPs, Cytokines
c. First Line of Defense
Fig. 16.1 p. 452, Table 16.2 p. 474
i. Physical
ii. Chemical
iii. Normal Microbiota
d. Second Line of Defense
Table 16.2 p. 474
i. Leukocytes- White blood cells
Fig. 16.1 p. 452, Table 16.1 p. 457, Table 16.2 p. 474
(WBCs)
1. Phagocytosisa. What cells are phagocytic?
b. Steps
c. Chemicals involved
2. Inflammation –
Fig. 16.8 p. 464
a. Signs & Symptoms
b. Functions, Causes and Effects
c. Examples of drugs used to decrease inflammation
d. Diseases caused by inflammation
3. Fever- Cause and Effects
4. Cytokines
a. Involvement in phagocytosis, inflammation, and fever
b. Examples- IL-1 and TNF: Effects
5. Antimicrobial Substances
a. Complement- How does it work? Functions?
b. Interferons- Functions
c. Iron-binding proteins- General importance
d. Antimicrobial Peptides
ii. Lymphatic System
1. Tissues and organs and cells
Fig. 16.5 p. 459
2. Functions
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II.
YouTube Assignment: Watch and take notes on a YouTube video
Basic Immunology: Nuts and Bolts of the Immune System
Go to YouTube online. Type “Basic Immunology: Nuts and Bolts of the Immune
System Anthony DeFranco” in the Search box to obtain the YouTube video.
For Exam 3- only the first 30 minutes (Total time of video 1:28:41). Exam 4 will
contain the remaining video information.
The following is an outline of, approximately, the first 30 minutes of the video.
Pertinent text material may be referenced.
The Players (Text Table 16.1 p. 457)

Sentinel cells in tissues
- Recognize foreign organisms and tissue damage, and recruit other immune cells
o Dendritic Cells
o Macrophages (See text- ‘fixed’ and ‘wandering’ macrophages)
o Mast cells (Provide protection against worms, bloodsucking insects such as ticks
but also involved in allergies & asthma)

Circulating phagocytes and granulocytes
o Neutrophils
o Monocytes (Turn into macrophage when move out of blood and into tissues)
o Eosinophils

Lymphocyteso B cells (Text- Humoral immunity- Produce antibodies)
o T cells (Cell mediated immunity)
o Natural Killer cells- Kills our virally infected cells and cancer cellsmorphologically similar to B & T cells, but function in innate immunity
o Also cause allergies and autoimmune diseases)
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Text pp. 463-465, Fig. 16.8
What are these called in the text?
Response to Infection I: Inflammation
1. Innate immune cells recognize large classes of molecules many microbes contain; will
recognize that something is ‘foreign’ but don’t recognize one specific species/strain (For
example- bacteria by recognizing LPS’s). Many of the cells in the innate immune system
have the same or very similar receptors on their surface that bond to these common
molecules on microbes.
Example:
Sentinel Cells
Dendritic cells
Recognize (able to bond to) certain molecules of large classes of foreign
organisms or tissue damage. This causes the release of…
Cytokines*
(cyto=cell, kine=action)
-Diffuse over to neighboring cells and blood vessels
-Attract other WBCs to the area (chemotaxis, Text p. 460)
Blood vessels respond in the area of damage
VasodilationIncreases blood
flow bringing more
WBSs to the area
Adhere ‘sticky’ molecules on the
surface of the blood vessel interior
endothelial cells
Increases permeability
‘Stops’ Circulating Cells at the area of
damage (For example: neutrophils,
monocytes)
Text- Other chemicals released by
injured cells include histamine &
prostaglandin
Allows these cells to ‘squeeze’
between the endothelial cells of the
blood capillaries and leave the
blood vessels, moving into the area
of damage/infection
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a. *Examples of important cytokines (There are about - about 50 known cytokines)
i. IL-1 (interleukin 1- acts on immune cells and other cells such as blood
vessel cells)
1. Numbered 1-35
2. Can act on WBCs and other cells
ii. TNF (tumor necrosis factor)
1. Too much can cause problems- rheumatoid arthritis, Crohn’s disease
2. Some drugs block TNF and may be used to treat certain diseases
like rheumatoid arthritis (example: Humira- we see the commercial
on TV a lot)
2. Blood vessels respond to cytokines in the area of damage
a. At the site of inflammation, cytokines alter cellular adhesion molecules on cells
lining blood vessels, i.e., put adhesion (sticky) molecules (chemokines- specific
type determine what type of white blood cell sticks and comes in) on the inner
surface of the blood vessel walls (endothelium=lining of blood vessels).
Cytokines causing this sticking response (margination- text p. 465) also occurs in
red bone marrow and causes release of phagocytes into circulation when they are
needed.
b. The circulating immune cells (phagocytes- neutrophils are the first to respond,
monocytes next which become macrophages)
i. Adhere to the inside walls of the blood vessels
ii. Then they squeeze between the endothelial cells of the blood vessels and
move out of the blood vessels and into the damaged/infected area (Text p.
465- diapedesis ‘amoeboid movement)
iii. Phagocytosis occurs
iv. Neutrophils come in first, die off fast, must be continually replenished
(pus mostly dead neutrophils)
v. Monocytes comes in after the neutrophils, develop into macrophages, and
clean up dead neutrophils, dead tissues, etc.
c. Blood vessels also allow fluid from the blood into the damaged/infected area
providing soluble components such as antibodies, clotting proteins (text) which
wall off infection (pus text)
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Killing of Microbes by Phagocytes



Text Fig. 16.7
Neutrophils and Macrophages directly recognize characteristic features on many
microbes’ cell surfaces and can ‘eat’ them (phagocytosis) and kill them once inside
Soluble immune components (innate components and antibodies) can coat the microbe
which allows phagocytes to eat them voraciously
Many microbes that can cause disease can do so because they are able to evade our
immune systems: phagocytes can’t ingest them or can’t kill them once inside
For Exam 3, only up to here. The rest will be included on Exam 4 for Chap. 17 Adaptive
Immunity.
YouTube Nuts and Bolts of Immunity Questions
1. List 3 ‘Sentinal Cells’ in the innate immune system.
2. What is meant by sentinel cells?
3. What is meant by ‘circulating’ cells in the innate immune system?
4. What are the lymphocytes?
5. What are the interleukins and TNF? When are they produced? What do they do?
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6. How do blood vessels respond to cytokines?
7. Describe the role of neutrophils and macrophages.
8. How do antibodies and soluble blood fluid components help phagocytosis?
9. What is margination (Text p. 465)?
10. How do neutrophils get out of the blood vessels?
11. Is inflammation beneficial? Explain.
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12. List the steps that occur in the inflammatory response starting with the sentinel cells
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