Innate immunity and inflammation Flashcards
What are the 6 types of innate immune cells?
Macrophage, monocyte, dendritic cell, NK cell, mast cell and Granulocyte (neutrophil, basophil and eosinophil)
What are the 2 types of specific immune cells?
T-cell and B-cell
What is the purpose of inflammation?
The purpose of inflammation is to eliminate the trigger that initiated the inflammatory reaction
What are the different types of guardian cells in the barrier organ (the skin)?
Macrophage, dendritic cell and mast cell
What does a macrophage do?
Recognition of danger signals => activation => phagocytosis (engulfs pathogen and produce free radicals) => pathogen killed
It can also be activated by inflammatory mediators and also produce them once activated (cytokines, chemokines and prostaglandins)
What does a dendritic cell do?
Recognition of danger signals leads to:
• uptake of antigen for transport to regional lymph nodes
• Production of pro-inflammatory cytokines
• In the lymph node: presentation of antigen by HLA
• Activation of naïve T-cells
What does a mast cell do?
Recognition of danger signals and neuropeptides leads to:
• Immediate release of inflammatory mediators (TNF for example)
• New synthesis of inflammatory mediators in
a second wave (prostaglandins, leukotrienes, cytokines and chemokines)
Generaly speaking, what are the 3 main steps when bacteria enters the body (trauma)?
- release of danger signals
- danger signals activates the guardian cells
- cells respond by producing pro-inflammatory substances and increase phagocytosis
What do activated guardian cells do to the endothelium in an acute inflammation?
At the site of damage/infection, the activation of guardian cells causes vasodilation and activation of the endothelium to recruit neutrophils and monocytes via up-regulation of integrins leading to a high population of neutrophils and monocytes at the damage/infection site
How are neutrophils recruited and what do they do?
• Recruited from blood and bone marrow via macrophage and mast cell signals
• Specialized for anaerobic conditions
• Short lived
• Pus forming
• Recognises danger signals
• Phagocytosing
Releases: tissue degrading enzymes, cytokines and free radicals
What are the 3 main inflammatory molecules secreted by liver cells during an acute inflammation?
TNF, IL-1 and IL-6
What is the complement system?
- A system of always present circulating molecules
- Inactive form in circulation
- Helps the immune cells to eliminate microbes
- Can also eliminate microbes without involvement of cells
What are the 5 functions of the complement system?
- Opsonisation
- Lysis of pathogens
- Chemotaxis
- Inflammation
- Cellular activation
What are the 3 main steps of resolution after an acute inflammation?
• Microbial threat is eradicated
• Healing of damaged tissue
• Induce memory of the adaptive immune system
If resolution doesn’t occur => high fiver, organ failure, etc.
If resolution doesn’t happen completely => chronic inflammation
What is the innate immunity?
Innate immunity is a non-specific host defence that exist prior to exposure to an antigen
