Integrated response to infection

Question 1

Immune response is d_______ and d_________

Answer 1

dynamic
diverse

Question 2

What are the four stages for sterilisation of pathogen

Answer 2

1. Establishment of infection
2. Inductive phase
3. effector phase
4. memory phase

Question 3

Establishment of infection

Answer 3

innate immune cells recognise non-self antigens

Question 4

Inductive phase [2]

Answer 4

cells become activated
differentiate in lymph node

Question 5

Effector phase

Answer 5

enter adaptive immune system (B and T cells)

Question 6

Memory phase [2]

Answer 6

effector function silenced
memory cells made

Question 7

Describe type 1 effector function [3]

Answer 7

• Th1 produces IGN-y
• activates macrophages
• target intracellular pathogens

Question 8

Describe type II effector function [3]

Answer 8

• Th2
• produces cytokines
  activates eosinophils, basophils and mast cells
• target extracellular pathogens

Question 9

Describe type III effector function [3]

Answer 9

• Th17 produces IL-17 and IL-22
• activates neutrophils
• target extracellular pathogens and fungi

Question 10

Define the term opportunist infection [3]

Answer 10

• lots of bacteria on the skin
• do not penetrate skin or cause infection
• until there is an opportunity (abrasion)

Question 11

Define the term acute infection [2]

Answer 11

• quick replication and spreading to new host
• before immunological response

Question 12

Define the term chronic infection [2]

Answer 12

• persisting long term
• avoiding elimination

Question 13

Identify complicating factors [3]

Answer 13

• numerous developmental stages
• numerous hosts
• many environments

Question 14

What is meant by absence of sterilising immunity [1]

Answer 14

Body is unable to get rid of parasite entirely

Question 15

Why are parasites harder to eliminate than bacteria?

Answer 15

• eukaryotes
• more like human cells

Question 16

Describe the leishmania species [5]

Answer 16

• host is sandfly
• draws blood which transfers pathogen
• various species
• gives rise to different types of diseases
• invades macrophages through phagocytosis

Question 17

Describe the role of neutrophils in the immune response to leishmania parasite [3]

Answer 17

• netosis: limit mobility
• activate macrophages, activating the adaptive immune response
• release CCL3 activating dendritic cells

Question 18

Describe the adaptive immune response to the leishmania parasite(Th cells) [3]

Answer 18

• Monocyte derived macrophage to lymph node
• releases IL-12
• causes Th0 cells to differentiate into Th1 cells

Question 19

Would mouse A (Th1 cell) or mouse B (TH2 cell) be best suited for killing the leishmania. Why?

Answer 19

• Mouse A
• Th1 invovled in activates macrophage action
• key in the immune response to leishmania

Question 20

Describe the schitosoma parasite? [3]

Answer 20

• parasitic worm
• infection in the intestine
• infected snails that bite and infect humans

Question 21

Briefly describe the lifecycle of the schitosoma [5]

Answer 21

• penetrates across unbroken skin
• locates blood capillaries
• feeds on blood, and carried by flow
• males and females pair
• females release eggs

Question 22

Identify how the parasite can be diagnosed [5]

Answer 22

• enlarged liver/spleen
• blood in urine
• eggs in stool
• IgM/IgG count high
• DNA from worms (PCR)

Question 23

What is another word for parasitic worm [1]

Answer 23

helminths

Question 24

Would mouse A (Th1 cell) or mouse B (TH2 cell) be best suited for killing the schitsosoma. Why?

Answer 24

• Mouse B would be best
• immunity relies on Th2 cells

Question 25

What interleukins does the Th2 cell release and what is their role [9]

Answer 25

- IL12: cell repair and increased mucous - IL-13: increased smooth muscle contractibility to expel worm - Produce Il-5: recuit and activate eosinophils - Produce IL-3 and IL-9: mast cell recruitment

Question 26

What is a granuloma?

Answer 26

cluster of leukocytes

Question 27

What is calcification

Answer 27

tissue hardening

Question 28

What is fibrosis

Answer 28

tissue thickening/scarring

Question 29

What cell is essential for the forming of granulomas?

Answer 29

macrophages

Question 30

Describe the difference between granulomas in an acute vs chronic infection [1]

Answer 30

In chronic infections cells (and tissues) are more organised

Question 31

What is the role of granulomas in terms of egg elimination

Answer 31

- facilitate the release of eggs

Question 32

Suggest why it is difficult to to design fungal drugs. [2]

Answer 32

- eukaryotic cells, similar to self cells - hard to kill fungus without damaging surrounding tissue

Question 33

How can mycosis be divided. Which is most dangerous [5]

Answer 33

- according to the body part it infects - superficial - subcutaneous - systemic (danger)

Question 34

How does COVID-19 fungal infection counts.[2]

Answer 34

- increase as it surpasses the immune system - secondary infarction

Question 35

Describe the Candida family [2]

Answer 35

- fungus colonises normal oral, GI and urogenital mucosa - disrupts mucosal barriers leads to persists superficial infection

Question 36

Describe the role of Dectin-1 in the recognition of fungal infections [4]

Answer 36

- highly expressed on dendritic cells - has C-type lectin carb recognition domain - recognises glucans on fungi surface - when engaged DECTIN-1 leads to production of inflammatory cytokines and ROS

Question 37

What does the immune system recognise on fungi? [3]

Answer 37

- conserved cell constituents - glucans mannas - galactins