Innate Immune Responses to Microbial Challenge

Question 1

Proinflammatory cytokines examples

Answer 1

Tumour necrosis factor

Interleukin-1

Question 2

Regulatory (activates adaptive immunity) cytokines examples

Answer 2

Interferon y

Interleukin-12

Question 3

Down-regulatory cytokines examples

Answer 3

Interleukin-10

Transforming Growth Factor b

Question 4

Chemoattractant cytokines example

Answer 4

Chemokines

Question 5

What properties do cytokines possess?

Answer 5

Pleiotropism
Synergism
Antagonism
Redundancy

Question 6

Roles of chemokines

Answer 6

Recruit leukocytes to areas of infection and inflammation

Important role in angiogenesis

Question 7

What releases interleukin-8?

Answer 7

Neutrophils & Monocytes

Question 8

What does IL-8 upregulate?

Answer 8

ß2 integrins

Question 9

Which chemokine does the herpes virus mimic and how?

Answer 9

IL-8Rß, using ECRF3

Question 10

What are the 3 pathways of activation?

Answer 10

Alternative pathway activated by microbe
Classical pathway activated by antibody
Lectin pathway activated by lectins e.g. MBL

Question 11

Early effects of complement activation

Answer 11

Inflammation (C3a)

Opsonisation and phagocytosis (C3b)

Question 12

Late effects of complement activation

Answer 12

Inflammation (C5a)

Lysis of microbe (Membrane Attack Complex)

Question 13

Role of matrix metalloproteinases

Answer 13

Key in tissue remodelling/embryonic development
Important immunological functions
-Leukocyte migration
-Activate/de-activate cytokines (eg TNF-a, CXCL8)
Excessive MMP activity destructive (e.g. rheumatoid arthritis, emphysema, tuberculosis)

Question 14

Components of innate immunity involved in microbial killing

Answer 14

Reactive oxygen intermediates
Reactive nitrogen intermediates
Lysosomal enzymes
Proteolytic enzymes
Microbiocidal peptides

Question 15

Where are defensins found?

Answer 15

In phagocytic cells & epithelial cells

Question 16

What do defensins target and their MOA?

Answer 16

bacteria, fungi and viruses, form pores in cell membranes

Question 17

Where are cathelicidins found?

Answer 17

In phagocytic cells & epithelial cells

Question 18

What bacteria use antigenic variation to avoid innate immunity?

Answer 18

Neisseria, Salmonella

Question 19

Which bacteria uses inhibition of complement activation to avoid innate immunity?

Answer 19

M. tuberculosis

Question 20

Which bacteria uses resistance to phagocytosis to avoid innate immunity?

Answer 20

Pneumococcus, Yersinia

Question 21

Which bacteria uses scavenging of Reactive Oxygen Intermediates (ROIs) to avoid innate immunity?

Answer 21

Catalase-positive Staphylococcus

Question 22

Which bacteria uses inhibition of phagolysosome formation to avoid innate immunity?

Answer 22

M. tuberculosis

Question 23

Which bacteria uses escaping from phagosome into cytoplasm to avoid innate immunity?

Answer 23

Listeria monocytogenes