Macrophage in inflammation

Question 1

What did Cornelius Celsius describe inflammation as?

Answer 1

Heat

Swelling

Redness

Pain

Question 2

What is the fifth cardinal sign added to the description of inflammation?

Answer 2

Loss of function

Question 3

What are the 3 conditions needed to build an immune system?

Answer 3

A recognition system

A communication system

A defense system

Question 4

What does the recognition system entail?

Answer 4

PAMPs and PRRs

Recognise non-self components

1996 - drosofila mutant without toll receptor succumbed to fungal disease

Question 5

What does the communication system entail?

Answer 5

Chemokines - recruit cells where needed

Neutrophils - monocytes - ect

Question 6

What is the process of diapedesis?

Answer 6

Cell in circulation start rolling on the cell surface

Selectins make it adhere

Integrins make it adhere firmly

Migrate between or through endothelial cells using PCAMS and JAMS

Question 7

What does PCAMS mean?

Answer 7

Platelet endothelial cell adhesion molecules

Question 8

What does JAMS mean?

Answer 8

Junctional Adhesion molecules

Question 9

What does the defence system entail?

Answer 9

Barrier/ complement system

Phagocytes

Membrane bound PRRs

PRR ligation results in cytokines and chemokine secretion

Coordination of responses by different cell types

Question 10

Appearance of monocytes

Answer 10

Relatively large cytoplasm

Horseshoe-shaped nucleus

LY6C and CXCR1 are cell surface proteins that can be stained with fluorescent antibodies

Question 11

How do monocytes develop?

Answer 11

Heamatopoietic stem cells differentiate into common monocyte precursors

Question 12

What are examples of resident macrophages?

Answer 12

Langerhans cells - skin

Kupffer cells - liver

Microglia - brain

Red pulp - spleen

Alveolar - lung

Question 13

How do macrophages develop?

Answer 13

Don’t develop in the blood

During the prenatal period CX3CR1+ precursors invade the tissues and lay down precursors

You are born with your macrophages in place

Slowly dividing cells

Have no input from the blood

Question 14

What is phagocytosis?

Answer 14

Major mechanism for the uptake and destruction of microbes and apoptotic cells which are > 0.5 microm

Otherwise endocytosis/ pinocytosis is used

Question 15

What are the 3 steps of phagocytosis?

Answer 15

Recognition - receptor mediated, object is to be taken up -> comes into contact with a surface receptor protein on the phagocyte

Uptake, signalling and actin-driven cytoskeletal remodelling - object is internalized and signals prepare cell for next step

Processing - killing, presentation or non-inflammatory removal (apoptotic cells)

Question 16

What are ways in which phagocytes kill the target cell?

Answer 16

ROS/ RNS

Proteolytic and hydrolytic enzymes

Antimicrobial peptides

Nutrient deprivation

Question 17

What are ways in which bacteria have evolved to evade immune strategies?

Answer 17

Mycobacteria - inhibit host enzyme for the maturation of phagolysosome

Listeria - uses mechanisms to escape initial membrane-bound vesicle. Gains access to thhe free cytoplasm

Question 18

What happens when there is excessive activation of the mononuclear phagocyte systems?

Answer 18

Leads to disease

Atherosclerosis - foam cells

Multiple sclerosis

Rheumatoid arthritis