Lecture 2 - The response to Infection

Question 1

What is the first stage of the immune response?

Answer 1

Awareness – recognition

Question 2

What are the receptors of the innate immune system? [6]

Answer 2

• Toll-like receptors
• Mannose receptors
• Dectin-1 receptors
• Scavenger receptors
• Lipids receptors
• Complement receptors

Question 3

What are Toll-like receptors?

Answer 3

A family of Pattern Recognition Receptors (PRRs).

Question 4

What do Toll-like receptors recognise?

Answer 4

• Pathogen-associated Molecular Patterns on pathogens

- Danger associated Molecular Patterns from damaged cells

Question 5

List five other PRRs and Damage receptors

Answer 5

• Nucleotide binding domain-like receptors (NLR)
• Retinoic acid inducible gene like receptors (RLR)
• C-type lectin receptors (CLR)
• Extracellular ATP (P2X7R)
• HMGB-1 (RAGE)

Question 6

What is the second stage of the immune response?

Answer 6

Immediate response: innate immune system

Question 7

What are the cellular responses to an infection during the innate immune system? [2]

Answer 7

• Phagocytosis

- Production of cytokines

Question 8

What are cytokines?

Answer 8

Hormone-like molecules of the immune system

Question 9

What are the four stages of phagocytosis? [4]

Answer 9

• Attachment
• Ingestion
• Killing
• Degradation

Question 10

What is the function of Interleukins (IL)?

Answer 10

Many diverse functions

Question 11

What is the function of Interferons?

Answer 11

Anti-viral

Question 12

What is the function of Colony-stimulating factors?

Answer 12

Haematopoiesis

Question 13

What is the function of tumor necrosis factors (TNF)?

Answer 13

Inflammation

Question 14

What is the function of Chemokines?

Answer 14

Chemotaxis

Question 15

List five cytokines that are released by macrophages. [5]

Answer 15

• IL-1 beta
• TNF-alpha
• IL-6
• CXCL8
• IL-12

Question 16

Explain what Paracrine signaling is?

Answer 16

• Cell-to-cell signalling

- The signal is sent to neighboring cells

Question 17

Explain what Autocrine signaling is?

Answer 17

When the signal released acts on the cell that released it

Question 18

Explain what Endocrine signaling is?

Answer 18

When the hormone is released into the blood and travels to the site of action

Question 19

Where are Mast cells mainly found?

Answer 19

At many tissue barriers (skin, gut, lung etc)

Question 20

What do Mast cells do when activated?

Answer 20

Degranulate to release their contents

Question 21

What are the immediate products of mast cell degranulation? [3]

Answer 21

• Histamine
• Heparin
• Various enzymes (chymase, tryptase)

Question 22

What are the delayed products of most cell degranulation? [3]

Answer 22

• Prostaglandins
• Leukotrienes
• Cytokines

Question 23

What is the role of Fibrinogen?

Answer 23

To cause blood clotting

Question 24

What is the role of Haptoglobulin?

Answer 24

Binds to iron

Question 25

What is the role of C3a (cleaved from C3)? [2]

Answer 25

- Activate mast cells | - Activate C3b (opsonin)

Question 26

What is the role of Mannis binding protein (MBP)?

Answer 26

It is an opsonin

Question 27

What is the role of C-reactive protein (CRP)?

Answer 27

- Binds phosphoryl choline | - Acts as an opsonin

Question 28

What is an Opsonin?

Answer 28

A molecule that binds to an infectious microbe making it more susceptible to phagocytosis

Question 29

What is the role of Interferons? [2]

Answer 29

- Binds to receptors on other cells to make them resistant to infection - Can also activate Macrophages and Natural Killer cells

Question 30

Name three interferons. [3]

Answer 30

- IFN-alpha - IFN-beta - IFN-gamma

Question 31

What are the two ways that interferons can act on infections? [2]

Answer 31

- Acts internally to protect the infected cell | - Secreted and binds to receptors on neighboring cells, triggering antiviral responses

Question 32

What is the role of Natural Killer cells?

Answer 32

To release lytic granules that kill some virus-infected cells

Question 33

Name three other cells of the innate immune system. [3]

Answer 33

- Eosinophils - Basophils - Innate Lymphoid cells

Question 34

What are the roles of Eosinophils? [2]

Answer 34

- Anti-pathogenic | - Roles within immune cell recruitment

Question 35

What are the roles of Basophils? [2]

Answer 35

- Anti-pathogenic | - Suppiorts generation of adaptive immunity

Question 36

What is the role of Innate Lymphoid cells?

Answer 36

Can support gut immune responses