Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

VMS 2009 > Immune response to pathogens > Flashcards

Immune response to pathogens Flashcards

1
Q

What are the three different types of pathogen that the immune system has defences against

A
  • Intracellular
  • Extracellular
  • Helminth parasites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is immunopathology?

A

Immune responses to pathogens that are the capable of causing tissue injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 4 different types of PRR receptors that recognise PAMP ligands?

A
  1. Toll-like receptors – TLRs – various locations
  2. C-type lectin receptors – CLRs – cell surface
  3. RIG-I like receptors – RLRs - cytosol
  4. Nod-like receptors – NLRs – cytosol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What immune response occurs when TLR 7 interacts with a virus?

A

it activates IL-12 cytokines which causes naive T cells to become T helper cells which induce interferons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What immune response occurs when a fungus/ bacterial polysaccharide binds to the c-lectin receptor dectin-1 ?

A

There is expression of IL-6 and IL-23 which polarises cells to become IL-17 producing TH17 cells, this the promotes the production of neutrophils and macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the first signal in T- Cell activation?

A

antigen-specific TCR engagement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the second signal in T cell activation?

A

contact with co-stimulatory ligands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the third signal in T cell activation?

A

cytokines directing T-cell differentiation into distinct effector cell
types

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do dendritic cells link the adaptive and innate immune response

A

they bring antigens from the site of infection and present them to T helper cells in lymph nodes which activates the T cells, allowing them to differentiate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the function of igA, igG, igM

A

virus and toxin neutralisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the function of igG on macrophages

A

opsonisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the function of igM on tumour cells?

A

complement fixation and formation of the membrane attack complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the function of a class I interferon?

A

made up of interferon alpha and beta, they are secreted by virus-infected cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What kind of infection does the MyD88 adapter protein defend against?

A

Invasive bacterial infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What kind of infection does the TLR-3 protein defend against?

A

Herpes simplex encephalitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What kind of infection does the Th1 pathway defend against?

A

“atypical” environmental mycobacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What kind of infection does the tH17 pathway defend against

A

Mucocutaneous candidiasis (fungus),
skin bacterial abscesses

18
Q

How do viruses typically enter host cells

A

through a cell-surface receptor, the genome replication is often error-prone which leads to mutations

19
Q

What is the function of a type II interferon?

A

modulator of adaptive immunity

20
Q

What is the difference between Killer cells and Cytotoxic cells?

A

Killer cells are part of the innate immune response and dont need to be activated to attack cells
Cytotoxic cells are part of the adaptive immune response and attack viruses when activated by an antigen

21
Q

What is the role of antibodies in the adaptive immune response?

A

They block infectious viruses early on in the course of infection

22
Q

What are five ways viruses can evade the immune response

A
  • Inhibition of apoptosis
  • Inhibition of type 1 interferon
  • production of immune modulators
  • engagement of inhibitory pathways
  • effection of immune cells
23
Q

How does antigen drift occur?

A

It occurs due to the high mutation potential of the RNA genome
the RNA viruses undergo mutation and recombination which alters their genome

24
Q

How does immune evasion occur in influenza A viruses?

A
  1. antigen shift occurs when different virus types try to infect a single cell
  2. RNA genome segments can then be swapped
  3. this creates new HA/ NA combinations
  4. a population may have little to no resistance against a new population
25
Q

Name three adverse effects of anti-viral immunity

A
  1. local acute inflammation
  2. systemic effects of inflammation
  3. antibody-dependent enhancement
26
Q

What is antibody-dependent enhancement?

A

Where an antibody actualy increases the ability of a virus to enter cells

27
Q

How can antibodies work against extracellular bacteria?

A
  • antibodies can neutralise the toxins produced by the bacteria
  • antibodies can activate the complement system that mediates lysis of bacteria through the MAC
28
Q

What mediates the defence against bacteria?

A

CHO- specific antibodies that can break down the bacterias polysaccharide capsule

29
Q

how do helpter T cells assist in fighting extracellular bacteria?

A

they activate macrophages that enhance phagocytosis

30
Q

What are some of the injurious effects of anti-bacterial immunity?

A
  • acute inflammation can cause tissue damage
  • In severe cases shock can occur, mediated by cytokines
31
Q

What are leishmania?

A

Protozoan parasites that live in macrophage phagosomes
Usually trasnmitted by sand flies

32
Q

Where do helminths typically enter the body?

A

through intestinal tracts

33
Q

How do helminths limit immunity in the host?

A

decrease external aG expression or they wrap themselves in host proteins to limit immunity

34
Q

What in ectoparasites triggers the immune response?

A

The ectoparasite blood feeding, e.g DAMPS/ Saliva etc.

35
Q

Give 6 things that ectoparasite saliva can cause

A
  1. Vasodilation
  2. Anticoagulation/ fibrinolysis
  3. Complement inhibitors
  4. Chemokine binding
  5. Immunosuppresants
  6. Inhibition of wound healing
36
Q

What mechanisms can help remove extracellular microbes?

A

antibodies, phagocytes, Th17

37
Q

What mechanisms can help remove intracellular microbes?

A

antibodies, phagocytes, Th1, CTL’s

38
Q

What mechanisms have evolved to help remove helminths?

A

igE, eosinophils, basophils, mast cells, TH2

39
Q

What TLR found on viruses drives an IL-12 response that leads to the differentiation of naive CD4 T cells to become IFN-g secreting Th1 cells?

A

TLR7

40
Q

What fungal and bacterial derived polysaccharide binds to DECTIN- 1

A

betaglucans

VMS 2009 (45 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions