Immunology Chapter 3

Question 1

Innate immune system responeses occurs in two phases, what are they

Answer 1

immediate and induced

Question 2

what is an example about immediate innate immune response

Answer 2

complement protein / system in the blood where phagocytic cells are already in the tissue

Question 3

what is an example of induce innate immune response

Answer 3

resident macrophages recruit phagocytic cells (neutrophils) from the blood stream into the site of infection

Question 4

what do you think the tissue resident macrophages are doing?

Answer 4

alarm and recruit more phagocytic cells
AND
make blood vessel wall sticky so neutrophils and more macrophages can get to the site of infection, engulf and kill them to initiate inflammatory response

Question 5

inflammation is caused by

Answer 5

physical or chemical insults by microorganisms

Question 6

inflammation helps….

Answer 6

recruit immune cells to fight infection

Question 7

there are two types of inflammation, what are they

Answer 7

acute and chronic

Question 8

what is acute inflammation

Answer 8

short, initial response to inflammation, causing little tissue damage

Question 9

what is chronic inflammation

Answer 9

long (months or years), persistent infection that destroys tissues

Question 10

how does chronic inflammation destroy tissues

Answer 10

by the continuous release of oxygen metabolites, nitric oxide, and proteases

Question 11

chronic inflammation happens due to microorganisms evolving too..,

Answer 11

evade host immune system

Question 12

the first step to the inflammatory response is detection and cytokine release…

what do macrophages use to detect bacteria

Answer 12

PRRs bind to pathogens and trigger phagocytosis

Question 13

What happens when TLRs detect PAMPs

Answer 13

they activate NF-KB, which turns on genes for pro-inflammatory cytokines

Question 14

What are the pro-inflammatory cytokines released by macrophages

Answer 14

TNF-a
IL-1
IL-6
CXCL8 (IL-8)

Question 15

What is the function of CXCL8

Answer 15

chemoattractant for neutrophils and monocytes

Question 16

The next step is Inflammatory signal and blood vessel changes. It starts with mast cells, what do they release?

Answer 16

histamine

Question 17

What effect do macrophage cytokines have on blood vessels?

Answer 17

increase permeability, allowing fluid, proteins, and immune cells to leak into tissues.

Question 18

What are two physical results of increased vessel permeability?

Answer 18

swelling and pain

Question 19

Then, immune cells enter tissues, but how?

Answer 19

Adhesion molecules help them stick to blood vessels and undergo extravasation.

Question 20

What allows extravasation

Answer 20

the weakening of the junctions between endothelial cells allowing neutrophils and monocytes to squeeze in

Question 21

How do immune cells find the site of infection?

Answer 21

They follow the CXCL8 chemokine gradient.

Question 22

The third step is phagocytosis and bacterial killing, which immune cells arrive first at the infection site?

Answer 22

Neutrophils

Question 23

What happens to monocytes at the infection site

Answer 23

mature into macrophages

Question 24

What happens after bacteria are engulfed by phagocytes

Answer 24

enclosed in phagosome

Question 25

the phagosome then fuses with lysosome, forming...

Answer 25

phagolysosome

Question 26

inside the phagolysosome, bacteria are killed by

Answer 26

NO Superoxide (O2-) Hydrogen peroxide (H2O2) Defensins (cationic peptides) Proteases

Question 27

4th step is clotting and repair, what does clotting do during inflammation

Answer 27

seals the wound to prevent spread of infection

Question 28

What begins after clotting?

Answer 28

Tissue repair and healing process

Question 29

Last step is the Pus Formation, what is pus made of

Answer 29

Dead and live neutrophils/macrophages Dead bacteria Skin cells Plasma (fluid)

Question 30

How would a macrophage or neutrophil identify an invading bacterium from some innocuous debris?

Answer 30

TLRs recognize PAMPs like LPS or peptidoglycan

Question 31

What are the products made by the cell when the transcription factor NF-κB has been activated?

Answer 31

for tissue resident macrophages: - transcription of cytokine and chemokine genes (IL-1, IL-6, TNF-a) for tissue resident dendritic cells - genes for maturation

Question 32

How do these products change the blood-vessel walls? How does this contribute to the inflammatory response?

Answer 32

Binding of TNF-a expresses adhesion proteins making blood vessel to become sticky so neutrophils and monocytes can interact with it. The cytokines weaken the junctions of endothelial cells, so blood vessel is leaky, so neutrophils and monocytes can roll in.

Question 33

What is the purpose of the inflammatory response?

Answer 33

eliminate infection