lecture 32 - innate immunity

Question 1

What type of immune responses is the inflammatory response?

Answer 1

Innate

Question 2

What is the overall process of the inflammatory response?

Answer 2

Chemical signals from tissue attract more cells, mature neutrophils enter blood from marrow, blood vessels dilate so neutrophils can squeeze through to injury

Question 3

Where do mature neutrophils for the inflammatory response originate?

Answer 3

Bone marrow

Question 4

What are the overall steps in phagocytosis?

Answer 4

Phagocyte adheres to pathogen, forms pseudopod that engulfs particle and forms a phagosome, phagosome fuses with lysosome to form phagolysosome to break down pathogen.

Question 5

What component of a phagocyte initially engulf particles at the cell surface, and what do they form?

Answer 5

Pseudopods on the cell surface form phagosomes/phagocytic vesicles inside the cell.

Question 6

How are phagolysosomes formed?

Answer 6

A lysosome fuses with a phagocytic vesicle/phagosome.

Question 7

How do phagolysosomes destroy pathogens?

Answer 7

By using toxic compounds, an acidic environment and lysosomal enzymes

Question 8

What toxic compounds do phagolysosomes use to destroy pathogens?

Answer 8

Reactive oxygen (hydrogen peroxide) and reactive nitrogen (nitric oxide)

Question 9

What form of reactive oxygen is found in phagolysosomes?

Answer 9

Hydrogen peroxide

Question 10

What form of reactive nitrogen is found in phagolysosomes?

Answer 10

Nitric oxide

Question 11

Is the pH high or low in a phagolysosome?

Answer 11

Low (acidic)

Question 12

What are the 3 classes of enzymes found in phagolysosomes?

Answer 12

Proteases, lipases, nucleases

Question 13

What are proteases?

Answer 13

Enzymes that break down proteins

Question 14

What type of enzyme breaks down proteins?

Answer 14

Proteases

Question 15

What are lipases?

Answer 15

Enzymes that break down fats/lipids

Question 16

What class of enzyme breaks down lipids/fats?

Answer 16

Lipases

Question 17

What are nucleases?

Answer 17

Enzymes that break down nucleic acids (e.g. DNA)

Question 18

What is the Complement cascade?

Answer 18

A component of the immune system that enhances the ability of anti-bodies and phagocytic cells to clear microbes and damaged cells.

Question 19

What is complement?

Answer 19

Proteins that act in sequence to clear pathogens in the immune response.

Question 20

How many major complement proteins are there?

Answer 20

9 - (C1-C9)

Question 21

What are the 3 key roles of the complement system/cascade?

Answer 21

Opsonisation, chemotaxis, lysis

Question 22

What is opsonisation, in terms of the complement system?

Answer 22

the binding and labelling of complement proteins to pathogens/antigens so they can be recognised by complement receptors on phagocytes.

Question 23

What is the term for binding labelling proteins to phagocytes, in the complement system?

Answer 23

Opsonisation

Question 24

What is chemotaxis?

Answer 24

A role of the complement system, which involves the recruitment and migration of phagocytes to the site of injury/inflammation

Question 25

What is the term for the recruitment of phagocytes to injury site, in the complement system?

Answer 25

Chemotaxis

Question 26

What is lysis?

Answer 26

The destruction of pathogen cells by rupturing the cell wall

Question 27

What is the term for the rupturing of pathogen cell walls, in the complement system?

Answer 27

Lysis

Question 28

What are the 3 complement pathways?

Answer 28

Classical, alternative, lectin

Question 29

What is the classical complement pathway?

Answer 29

A pathway that triggers the complement cascade by binding a pathogen-bound antibody to complement.

Question 30

What is the alternative complement pathway?

Answer 30

Pathogen binds complement to surface/pathogen component

Question 31

What is the lectin complement pathway?

Answer 31

Carbohydrate components of microbes bind to complement.

Question 32

What are the 3 complement pathways amplified by?

Answer 32

enzyme complex - C3 convertase

Question 33

What are microbes coated with during opsonisation/labelling, and what does this enable?

Answer 33

Antibody or complement fragment C3b - allows them to be attracted to phagocytes for destruction

Question 34

What is the process of destruction in the complement pathway of innate immunity?

Answer 34

Microbes coated with complement fragment c3b are phagocytised. Complement protein C9 allows for the assembly of membrane attack (MAC) complex creates pores that lead to lysis.

Question 35

What is the process of recruitment in the complement pathway?

Answer 35

Phagocytes are attracted into the site of injury/infection. Mast cells are degranulated by complement proteins C3a and C5a, releasing inflammatory mediators that tract phagocytes.

Question 36

What proteins degranulate mast cells in recruitment of the complement pathway?

Answer 36

C3a and C5a

Question 37

What are inflammatory mediators?

Answer 37

Substances released during the degranulation of mast cells.

Question 38

How does recruitment lead to the attraction of phagocytes to a site of infection?

Answer 38

Inflammatory mediators released from mast cells include proteins that attract phagocytes.

Question 39

What is the term given for the clinging of neutrophils to capillary walls in an innate reaction to a peripheral site of early infection/inflammation?

Answer 39

Margination

Question 40

What is the name given to the process in which mature neutrophils are released from bone marrow to facilitate an immune response?

Answer 40

leukocytosis

Question 41

What is diapedesis?

Answer 41

When neutrophils travelling to an inflammatory response squeeze through capillary walls to exit blood stream

Question 42

What complement protein leads to “destruction” via the creation of a MAC?

Answer 42

C9

Question 43

What is the function of C3 convertase enzyme?

Answer 43

Breaks C3 complement protein into C3a and C3b