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Flashcards in Innate immunity Deck (31)
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1
Q

Describe the innate immune system

A

Rapid response
Recognises a limited number of different structures
Doesn’t change upon re exposure

2
Q

Describe the adaptive immune system

A

Takes time to develop
Highly specific for a vast number of different structures
Response improves upon re-exposure
“Immunological memory”

3
Q

What do immune cells derive from?

A

Hematopoietic stem cell

4
Q

What are the two subsets of immune cells?

A

Common lymphoid progenitor cell

Common myeloid progenitor cell

5
Q

What are macrophages derived from?

A

Monocytes

6
Q

Where do monocytes differentiate into macrophages?

A

In the blood

7
Q

What is the main role of a macrophage?

A

To phagocytose and kill bacteria

Remove apoptotic cells

8
Q

What do macrophages use to recognise non-self cells?

A

They use pattern recognition receptors (PRR)

To recognise pathogen associate molecular patterns (PAMPs)

9
Q

How does a macrophage phagocytose a bacteria?

A

Kills them inside a phagolysosome
Acidification
Production of oxygen and nitrogen free radicals
Proteolytic enzymes

10
Q

What does a macrophage do after it has killed a bacteria?

A

It prevents antigens of the bacteria
This is on the cell membrane protein MHC II
This is recognised by a T-cell
T-cell is activated
T-cell releases cytokines to promote further macrophage action

11
Q

Why do macrophages produce pro inflammatory cytokines?

A

Attracts other immune cells to the site of infection

Causing inflammation

12
Q

Name an effect of cytokines in the liver

A

Acute-phase proteins released

Activates the complement system

13
Q

Name an effect of cytokines of bone marrow endothelium

A

Neutrophil mobilisation

Increases phagocytosis

14
Q

Name an effect of cytokines on the hypothalamus

A

Increased body temperature
Increases antigen processing
Decreases viral and bacterial replication

15
Q

Name an effect of cytokines on fat and muscle

A

Metabolisation of protein and energy stores to raise body temperature

16
Q

Name an effect of cytokines on dendritic cells

A

Migration of dendritic cells to lymph nodes
They mature in the lymph nodes
Initiates the adaptive immune response

17
Q

Name the four types of macrophage

A

Kupffer cell
Alveolar macrophage
Osteoclast
Microglial cell

18
Q

What is a Kupffer cell?

A

Removes circulating bacteria and apoptotic cells in the liver sinusoids

19
Q

What is an alveolar macrophage?

A

Removes inhaled pathogens and other particles from the lungs

20
Q

What is an osteoclast?

A

Regulates bone density

21
Q

What is a microglial cell?

A

Scavange dead cells, plaques and microbes in the brain

22
Q

Describe a neutrophil

A
Most abundant leukocyte
Short lifespan 1-3 days
Circulates in the blood
Recruited to sites of infection
Phagocytose and kill bacteria
23
Q

How do neutrophils enter tissues?

A

Neutrophils circulate in the blood
Macrophages release cytokines when they notice an infection
Cytokines are displayed by the endothelium
Cytokines activate the endothelium
Neutrophils enter tissue

24
Q

Name the four stages to a neutrophil crossing the endothelium

A

Rolling adhesion
Tight binding
Diapedesis
Migration

25
Q

How do neutrophils destroy bacteria?

A

Phagocytosis
Phagosome binds with primary and secondary granules
Rac2 induces NADPH oxidase producing O2-
Acidification releases granule proteases

26
Q

Which cells deal with pathogens that are too large to be phagocytosed?

A

Mast cells
Basophils
Eosinophils

27
Q

What is a natural killer cell?

A

Derived from same precursor as lymphocytes

They recognise virally infected cells

28
Q

Describe the action of a natural killer cell

A

Recognises patterns specific to viral infection
Releases granules that kill the virally infected cell
Cell is then digested by macrophages

29
Q

What do dendritic cells do?

A

Take up microbial material

Migrate to lymph nodes to activate T cells

30
Q

What activates the cells of the innate immune system?

A

C3

31
Q

What do virally infected cells express?

A

Type 1 IFN