9.28.2022. + 9.30. 2022. Study Questions

Question 1

Describe the functions of lysozyme

Answer 1

degrades peptidoglycan in bacterial cell walls

Question 2

Describe the function of transferrin

Answer 2

iron-binding protein

Question 3

Describe the function of gastric acid

Answer 3

protects the body against pathogens that are ingested with food or water

Question 4

Compare skin and mucus membrane as first line defenses

Answer 4

SKIN:
- tough
- microbes flake off as skin cells do
- water-proof

MUCOUS MEMBRANE:
- bathed with secretions that wash microbes from the surface
- constant turnover of cells –> take microbes with them
- lined with ciliated cells

Question 5

Which components of the innate immune system can first detect a microbial invasion?

Answer 5

physical barriers (skin, mucous membrane)
normal flora of the body
antimicrobial substances (lysozyme, transferrin, lactoferrin, gastric acid)

Question 6

Describe how surface receptors and cytokines allow the cells of the immune system to communicate

Answer 6

Surface receptors: eyes and ears of a cell. span the cell membrane, connecting the outside of the cell with the inside of the cell, allowing the cell to sense and respond to external signals.

Cytokines: voices of a cell. a cytokine produced by one cell diffuses to another and binds to the appropriate cytokine receptor of that cell, the binding induces a change in the cell such as growth, differentiation, movement, or cell death.

Question 7

List three bacterial components recognized by toll-like receptors

Answer 7

LPS, lipoprotein, flagellin

Question 8

Describe three outcomes of complement activation

Answer 8

1. inflammatory response
2. opsonization
3. lysis of foreign cells

Question 9

Describe the alternative pathway of complement activation

Answer 9

triggered when C3b binds to foreign cell surfaces, which allows other complement proteins to then attach, eventually forming the C3 convertase. used if you’ve never seen the pathogen before.

Question 10

What are the functions of C3b?

Answer 10

opsonin. binds to, coats, and marks a cell to be phagocytosed, aka marks it for eating. OR combines with C3 convertase to form an enzyme that splits C5.

Question 11

What are the functions of C5a? (2)

Answer 11

• chemoattractant, drawing phagocytes to the area where the complement system has been activated
• C3a + C5a = inflammatory response + contribute to local vascular permeability

Question 12

who’s awesome?

Answer 12

i’m awesome!

Question 13

What is an NLR?
what does it stand for, what does it lead to, what is it?

Answer 13

NOD-like receptor. inflammatory response. PRRs within cells

Question 14

What is an RLR?
what does it lead to?
what is its job?

Answer 14

RIG-like receptor. leads to interferon response. PRR within cells, distinguish viral RNA from normal cellular RNA.

Question 15

Compare and contrast TLRs, NLRs, and RLRs. where are they found?

Answer 15

NLRs and RLRs: floating around, they are receptors in the cytoplasm
TLR: found on the surface or inside phagosomal membrane. they are membrane bound.

Question 16

How can a cell recognize it is infected with a virus?
what about viral infections specifically?

Answer 16

using NLRs and RLRs, which are both found in the cytoplasm of the cell. in viral infections, RLRs will typically be the proteins that recognize viral infection, since they detect viral DNA

Question 17

What does a cell do in response to recognizing that it is infected with a virus?

Answer 17

IFN (interferon) response is triggered. IFN response is triggered when the RLRs detect the presence of viral nucleic acid (RNA). the interferon alerts immune cells to the presence of the virus, and promotes an antiviral response. IFN is produced in the infected cells and diffuses to neighboring cells. the infected cell will undergo apoptosis. IFN activates iAVP synthesis in neighboring cells, so that when the virus goes to infect these cells, they will immediately undergo apoptosis, preventing viral replication.

Question 18

What are dendritic cells?
What do they do?
They are a____, n____ _ cells

Answer 18

phagocytes that engulf material, bring it to the adaptive immune system for “inspection,” active naive T cells

Question 19

What are macrophages?

Where do they reside, and what two jobs do they do?

Answer 19

phagocyte that resides in tissues. they scavenge debris, and produce pro-inflammatory cytokines

Question 20

What are neutrophils?

Answer 20

major phagocytic cell in blood, move to infected tissues where they destroy invading microbes

Question 21

Compare and contrast dendritic cells, macrophages, and neutrophils?

Question 22

Draw all the steps of the inflammatory process

Question 23

What is the role of adhesion molecules in recruiting neutrophils to sights of inflammation?

Answer 23

molecule on the surface of a cell of the body that allows that cell to adhere to other body cells

Question 24

Which cytokines are pro-inflammatory?

Answer 24

TNF, IL-1, IL-6

Question 25

Which cytokines are anti-inflammatory?

Answer 25

IL-10

Question 26

What is apoptosis?
why would a cell do it?

Answer 26

programmed cell death that does not cause inflammation

Question 27

What is pyroptosis?

Answer 27

programmed cell death that elicits an inflammatory response

Question 28

How does fever aid infection clearance?

Answer 28

prevents some microbes from growing, and enhances some protective processes

Question 29

what are pro-inflammatory cytokines? name the most important pro-inflammatory cytokines.

Answer 29

contribute to the inflammatory response. TNF, IL-1, IL-6.

Question 30

what is a TLR? where are they located? what does TLR stand for?

Answer 30

toll-like receptor. pattern recognition receptors located on the surface of cells and within endosomes.

Question 31

inflammasome = ?
what is it?
what does it activate, and what does that initiate?

Answer 31

protein complex in macrophages
potent proinflammatory cytokine
inflammatory response

Question 32

why can an RLR distinguish viral RNA from normal cellular RNA?

Answer 32

1. viral RNA is often double-stranded
2. viral RNA often lacks a cap