Basic Concepts - 1B

Question 1

What are macrophages sensors of?

Answer 1

The health of tissues

Question 2

What type of generalised receptors can macrophages recognise material (soluble and particulate)?

Answer 2

Opsonisation and non-opsonic receptors

Question 3

Is direct recognition opsonic or non-opsonic?

Answer 3

Non-opsonic

Question 4

Is indirect recognition opsonic or non-opsonic?

Answer 4

Opsonic
- antibody-Fc receptor
-complement-complement receptor

Question 5

What are CD200L and SIRP?

Answer 5

Inhibitory receptors

Question 6

What does SIRP engage?

Answer 6

CD47 and particles that contain CD47 are not phagocytosed for example

Question 7

What receptor is high affinity for IgG1?

Answer 7

CD64 - highly expressed on macrophages

Question 8

What do CD64 receptors do very effectively?

Answer 8

Internalise anything opsonised

Question 9

Are Fc receptors activating or inhibitory?

Answer 9

They can be activating and inhibitory

Question 10

What is the process of Endocytosis turning acidic?

Answer 10

In endosome, mature into late from early and become more acidic
Then fuse with lysosomes and there will be complete degradation of material

Question 11

What is a phaogosme combined with a lysosomes called?

Answer 11

Phagolysosomes

Question 12

Why doesn’t a dendritic cell want to degrade everything?

Answer 12

Wants peptides to be able to deliver to T cells?

Question 13

What are the microbicidal products of phagocytes?

Answer 13

• acidification
• toxic oxygen derived products
• toxic nitrogen oxides
• antimicrobial peptides
• enzymes
• competitors

Question 14

What is the microbicidal activity used to make phagosomes as inhospitable as possible?

Answer 14

Toxic species damage bacterial proteins and DNA
Iron pump to remove iron fro phagosome
Antimicrobial peptides

Question 15

What type of oxidase is responsible for production of radical species?

Answer 15

NADPH oxidase

Question 16

What is autophagy?

Answer 16

A physiological process involved in the disposal of cytosolic material , relevant in clearance of intracellular pathogens

Question 17

When do cells undergo autophagy?

Answer 17

In response to infection or nutrient starvation

Question 18

What is the process of autophagy?

Answer 18

Formation of a double membrane that will embed whatever has triggered it
Then fuses with lysosome and forms an auto lysosome

Question 19

What is autophagy controlled by?

Answer 19

MTOR

Question 20

Where are kupffer cells found and what do they do?

Answer 20

Found in the middle of sinusoids filtering everything going through the liver

Question 21

All macrophages share a particular set of functions but what makes them different between themselves?

Answer 21

Each organ has different environments which dictate different gene expression

Question 22

What is the difference between macrophages in mucosal tissues and in internal organs?

Answer 22

In mucosal tissues, more exposure to pathogens, higher threshold of activation
In internal organs, lower activation threshold, less exposure to pathogens

Question 23

What do osteoclasts (type of macrophage) do?

Answer 23

Mediate bone remodelling

Question 24

What are bone marrow macrophages essential for?

Answer 24

Erythropoiesis

Question 25

What are involved in brain development through synaptic maturation?

Answer 25

Microglia

Question 26

What cells mediate iron recycling through erythrophagocytosis?

Answer 26

Kupffer cells and red pulp macrophages (spleen)

Question 27

What do macrophages make contact with cardiomyocytes through?

Answer 27

Connexin 43 (CX43)-containing gap junctions

Question 28

How do the gap junctions help macrophages make contact with cardiomyocytes?

Answer 28

Positive charge travels through the gap junction between cardiomyocytes and a macrophage

Question 29

What are the problems with cardiomyocytes?

Answer 29

Mitochondria can get damaged easily

Question 30

Contribution of monocytes to maintenance of tissue macrophage populations varies among organs and depends on self-renewal capacity of resident macrophages and accessibility to blood of particular organ… put these in order of macrophage turnover due to blood accessibility. 1) Skin dermis and intestine 2) epidermis, lung and brain 3) spleen and kidney

Answer 30

1) skin dermis and intestine - rapid macrophage turnover , rely on monocyte recruitment 2) spleen and kidney - contain variable percentages of foetal and monocyte-derived macrophages 3) epidermis, lung and brain - low access to blood. Langerhans cells, alveolar macrophages and microglia depend on self-renewal of resident macrophages

Question 31

Where are all monocytes generated from in adulthood?

Answer 31

Definitive HSC from monocyte-macrophage-dendritic cell progenitors

Question 32

Where do classical monocytes move to?

Answer 32

Into tissue

Question 33

What happens to monocytes during inflammation?

Answer 33

Monocyte will be activated and recruited to tissue and differentiate into macrophages that can disappear or maintain cellular replication

Question 34

What can a dendritic cell activate that macrophages can’t?

Answer 34

Naive T cells

Question 35

What can both dendritic cells and macrophages both do?

Answer 35

Phagocytosis Both migrate

Question 36

What are the two ends of the spectrum of macrophage activation profiles?

Answer 36

M1 - classically activated macrophages M2 - alternatively activate macrophages

Question 37

What cytokine do NK cells produce lots of?

Answer 37

Gamma interferon

Question 38

What do eosinophils and mast cells produce lots of?

Answer 38

Il-4

Question 39

Are M1 or M2 inflammatory or anti-inflammatory?

Answer 39

M1 - inflammatory, promotes Th1 response M2 - anti inflammatory promotes Th2 response

Question 40

What type of cytokines are TNF alpha, IL-6 and IL-1beta?

Answer 40

Inflammatory cytokines

Question 41

what type of cytokine is IL-10?

Answer 41

Anti-inflammatory, wound healing

Question 42

What does arginase do?

Answer 42

Dampen immune response

Question 43

What cells are rich in arginase?

Answer 43

Myeloid suppressor cells

Question 44

What is in NK cells to enable them to have some memory?

Answer 44

Epigenetic modelling of chromatin, some areas of chromatin have the histone to be modified and more accessible