Innate immunity, acute inflammation Flashcards
(40 cards)
PAMPS/MAMPS
Pathogen/Microbe Associated Molecular Pattern
A conserved structural component of microbes/fungi/viruses that is sensed by the innate immune system
Pattern Recognistion Molecules
Component of the innate immunse system that binds to and recognizes PAMPS
What happens upon recognition/binding of PAMPS by the Pattern Recognition Molecules of the innate immune system?
- Phagocytosis (eg mannose receptor)
- Opsonization (eg. soluble lectins)
- Killing and breakdwon (eg lysozyme)
- Production of inflammatory mediators (eg TLRs, NLRs, RLRs)
What do macrophages release when activated and what does this initiate?
- Cytokines (TNF-a and IL-1B)
- Chemokines (IL-8)
This initiates the inflammatory response by causing vasodilation and increased vascular permeability (Causing redness/heat/edema)
Inflammatory cells can now migrate into tissues and release inflammatory mediators that cause pain
Cell surface TLR (Toll-Like Receptor) action
When activated (primarily by bacteria and fungi):
- Increase expression of Cytokines, adhesion molecules, and costimulators
- Cause acute inflammation
- Stimulate adaptive immunity
What type of cells have Toll-Like Receptors?
TLRs are primarily on innate immune cells like Macrphages and Dendritic Cells as well as non-immune cells such as fibroblast cells and epithelial cells
Endosomal Toll-Like Receptor (TLR) action
When activated (primarily by bacterial and viral particles):
- Produce type 1 interferon (IFN a, b)
- Activate antiviral state
Where are NOD-Like Receptors (NLRs) located?
In the cytoplasm
NOD-Like Receptor (NLR) action
When activated by bacteria or tissue damage:
- Leads to the secretion of IL-1B
- IL-1B then causes acute inflammation
Process of Leukocyte Migration (eg Neutrophils)
What cell produces histamine?
Basophils and Mast Cells
What does histamine do?
Histamine increases the permeability of the capillaries to WBCs and some proteins, to allow them to engage pathogens in the infected tissues
Cytokines
A broad category of small proteins important in cell signaling
Chemokines
Class of cytokines with functions that include attracting WBCs to sites of infection
Prostaglandins
Group of compounds with varying hormone-like effects; control processes such as inflammation, blood flow, blood clots formation, and the induction of labour
TNF-a
(Tumor Necrosis Factor-alpha)
A cytokine that causes:
- Endothelium vascular leakage and WBC recruitment
- Fever
Which cytokines act on the brain to cause fever?
IL-1
IL-6
TNF-a
IL-1
(Interleukin-1)
A cytokine that causes:
- Fever
- Acute inflammation
- Endothelium to express adhesion molecules
- Induction of chemokine secretion that recruits WBCs
IL-6
(Interleukin-6)
A cytokine that causes:
- Fever
- Production of acute-phase proteins
What cytokines act on the liver to cause acute phase protein production?
- IL-1
- IL-6
What cytokines act on the bone marrow causing leukocyte production?
- TNF
- IL-1
- IL-6
IL-8
(Interleukin-8)
A cytokine that acts as the major chemotactic factor for neutrophils
Phagosome
A vacuole in the cytoplasm of a cell, containing a phagocytosed particle enclosed within a part of the cell membrane.
How do cells kill the microbes within the phagosomes after phagocytosis?
- Phagosome fuses with lysosome
- The microbe is killed by:
- ROS (Reactive Oxygen SSpecies)
- NO (Nitric Oxide)
- Lysosomal Enzymes
