Macrophage in inflammation Flashcards
What did Cornelius Celsius describe inflammation as?
Heat
Swelling
Redness
Pain
What is the fifth cardinal sign added to the description of inflammation?
Loss of function
What are the 3 conditions needed to build an immune system?
A recognition system
A communication system
A defense system
What does the recognition system entail?
PAMPs and PRRs
Recognise non-self components
1996 - drosofila mutant without toll receptor succumbed to fungal disease
What does the communication system entail?
Chemokines - recruit cells where needed
Neutrophils - monocytes - ect
What is the process of diapedesis?
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
What does PCAMS mean?
Platelet endothelial cell adhesion molecules
What does JAMS mean?
Junctional Adhesion molecules
What does the defence system entail?
Barrier/ complement system
Phagocytes
Membrane bound PRRs
PRR ligation results in cytokines and chemokine secretion
Coordination of responses by different cell types
Appearance of monocytes
Relatively large cytoplasm
Horseshoe-shaped nucleus
LY6C and CXCR1 are cell surface proteins that can be stained with fluorescent antibodies
How do monocytes develop?
Heamatopoietic stem cells differentiate into common monocyte precursors
What are examples of resident macrophages?
Langerhans cells - skin
Kupffer cells - liver
Microglia - brain
Red pulp - spleen
Alveolar - lung
How do macrophages develop?
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
What is phagocytosis?
Major mechanism for the uptake and destruction of microbes and apoptotic cells which are > 0.5 microm
Otherwise endocytosis/ pinocytosis is used
What are the 3 steps of phagocytosis?
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)