Innate Immunity

Question 1

What is the difference between the innate and adaptive immune system?

Answer 1

Innate: non-specific, immediate
Adaptive: specific, delayed

Question 2

What are the main factors involved in innate immunity?

Answer 2

Epithelial barrier with tight junctions
Mucus
Enzymes
Phagocytosis
Complement system

Question 3

How is mucus effective?

Answer 3

Trap bacteria so they cannot adhere to surface

Question 4

What are the steps of phagocytosis?

Answer 4

Phagocyte recruited by chemokines and complements
Phagocyte binds to pathogen
Pathogen is internalised to phagosome
Phagosome fuses with lysosome
Pathogen destroyed by nitrous oxide

Question 5

5 examples of antibacterial peptides?

Answer 5

Alpha Beta defensiva
Lysozyme
Lactoferrin
Phospholipase A
Histatins

Question 6

What are 3 ways of activating the complement cascade?

Answer 6

1. Classical
2. MB lectin
3. Alternative

Question 7

What are the 3 outcomes of the complement cascade?

Answer 7

1. Recruitment of inflammatory cells
2. Opsonisation of pathogen
3. Killing of pathogen via lysis

Question 8

What is the classical pathway activated by?

Answer 8

C1q interacts with antibody:antigen complex

Question 9

What is lectin?

Answer 9

Carbohydrate binding protein

Question 10

Why can lectin bind to microbes?

Answer 10

Mannose in microbes cell surface

Question 11

How is the MB lectin pathway initiated?

Answer 11

MB lectin binds to mannose

Question 12

How is the alternative pathway initiated?

Answer 12

C3 cleavage

Question 13

What are the actions of C3a and C5a

Answer 13

Inflammatory mediators

Question 14

What are the inflammatory mediators effects?

Answer 14

Increase vascular permeability
Increased fluid leakage
Migration of macrophages, PMNS and lymphocytes increased
Microbicidal activity increased

Question 15

What is chemotaxis?

Answer 15

Movement of cell down a chemical gradient
Low-high concentration

Question 16

How do microbes hide?

Answer 16

Evolved capsules

Question 17

What is opsonisation?

Answer 17

Coating of a particle with proteins
Facilitate phagocytosis by macrophages or dendritic cells

Question 18

What immune cells are associated with innate immunity?

Answer 18

Myeloid cells
Granulocytes, monocytes, macrophages, and dendritic cells

Question 19

What lymphoid cells are associated with innate immunity?

Answer 19

Natural killer cells
Mature dendritic cells

Question 20

What granulocytes exist in blood?

Answer 20

Neutrophils
Eosinophils
Basophils
Monocytes

Question 21

What are the innate immune cells in tissues?

Answer 21

Mast cells
Macrophages

Question 22

How many cells/litre are there of neutrophils?

Answer 22

5x10^9

Question 23

What % of total WBCs are neutrophils?

Answer 23

75%

Question 24

What are the types of phagocyte cells?

Answer 24

Neutrophils
Monocytes/macrophages
Dendritic cells

Question 25

How do we recognise pathogens?

Answer 25

Opsonisation PRRs - pathogen recognition receptors

Question 26

What are 2 examples of PRRs?

Answer 26

Toll like receptors C type lectins

Question 27

What are the 3 outcomes of a PRR recognising a pathogen?

Answer 27

Phagocytosis Secretion of inflammatory mediators Secretion of cytokines

Question 28

What are cytokines?

Answer 28

Small glycoproteins Used in cellular communication

Question 29

What do pro inflammatory cytokines do?

Answer 29

Activate macrophages Stimulate inflammatory mediators release Activate adaptive immune system

Question 30

What are examples of pro inflammatory cytokines?

Answer 30

Interleukins a and b TNFa Interferon g

Question 31

What do anti inflammatory cytokines do?

Answer 31

Antagonistic to pro inflammatory cytokines Mediate adaptive immune response IL 4 & TGF b

Question 32

What do growth factors do?

Answer 32

Develop immune cells Stimulate growth and proliferation

Question 33

What do chemokines do?

Answer 33

Recruit immune cells

Question 34

What cytokine is produced by all cells in response to viral infection?

Answer 34

Type 1 interferons Shut down protein and DNA synthesis Activate immune cells to destroy infected cell

Question 35

What is the timeline of infection?

Answer 35

Physical barrier Humoral components: complement, antimicrobiano peptides PRRs Recruitment and activation of phagocytes Activation of adaptive immunity