Innate Immunity Flashcards
What are 5 characteristics of inflammation?
Heat Redness Swelling Pain Loss of function
What kind of cells lead to inflammation?
Mast Cells
Prostaglandins
Leukotrienes
Histamine
What are the 3 cytokines that lead to a fever?
TNF
IL-1
IL-6
*These are very important
How does the innate immune system discriminate between self and non-self? Why?
Pathogen Associated Molecular Patterns (PAMPS)
Because they have no structural similarity with self Ags
Which Toll Like Receptor (TLR) for Lipopolysaccharides?
Is this intracellular or extracellular?
What kind of bacteria does this TLR bind?
TLR-4
Extracellular
Gram Negative
Which Toll Like Receptor (TLR) for ds VIRAL RNA?
Is this intracellular or extracellular?
TLR-3
Intracellular
Which Toll Like Receptor (TLR) for ss VIRAL RNA? What disease is this associated with?
TLR-7 and TLR-8
Intracellular
HIV is TLR 7**
FLU is TLR 8**
Which Toll Like Receptor (TLR) for Unmethylated CpG DNA- bacteria?
TLR-9
Intracellular
What do TLRs activate?
Nuclear Factor Kappa B (NFkB), which promotes expression of various cytokines that lead to inflammation
Describe the signaling pathway for TLRs and what they activate?
Extracellular TLRs activate MyD88, which increases the expression of NFkB and Interferon Regulatory Factor (IRF), both of which activate pro-inflammatory cytokines
Intracellular TLRs (3 and 4) activates TRIF, which increases the expression of NFkB and Interferon Regulatory Factor (IRF), both of which activate pro-inflammatory cytokines
What is the role of NOD-like receptors?
To form the inflammasome, which is used to activate caspase-1, which activates IL-1 and induce acute inflammation
How does inflammation occur without an infection or introduction of new bacteria?
Damage Associated Molecular Patterns (DAMPs) are released from damaged or dying cells
DAMPs activate the innate immune system by interacting with PRRs and activating NFkB.
What 3 ways do DAMPs activate NFkB?
High Mobility Group Box 1 (HMGB1), which is released from necrotic cells and bind to TLR2 and TLR4 to activate NFkB
Uric acid from necrotic cells bind to NOD-like Receptor P3 (NLRP3), which activates NFkB
Heat Shock Proteins (HSPs) are released from necrotic cells and bind to TLR2 and TLR4, which activates NFkB
All DAMPs stimulate the production and release of ___ and ____
TNF-alpha
IL-1
What are the 3 pathways of the complement system?
Alternative Pathway
Classical Pathway
Lectin Pathway
In individuals with acute and chronic inflammation, what 2 acute phase proteins are elevated?
C-Reactive Protein (CRP)
Serum Amyloid A (SAA)
How do neutrophils move into tissues from the blood?
Extracellular cells in the circulatory pathway that are activated express P-selectin and binds to E-selectin on adhesion molecules. This begins the rolling process.
LFA-1 and VLA-4 on the leukocyte bind to ICAM1 and VCAM1 on the activated endothelial cells, respectively. This begins the adhesion and transmigration process.
How are Classically activated M1 Macrophages activated?
Binding of TLRs and IFN-y induce inflammation
How are Alternatively activated M2 Macrophages activated?
M2 Macrophages are induced by IL-4 and IL-13 for tissue repair
What does Superoxide dismutase breakdown?
Superoxide
What breaks down Hydrogen Peroxide?
Catalase
What kind of pathogen is inflammation not an efficient mechanism of defense?
Viruses
What 2 signals mediate anti-viral innate immunity?
Type I Interferons- block viral replication within host cells
Natural Killer Cells- kill viral infected cells
Describe the process of how NK cells kill infected cells?
NK cell releases PERFORINS, which form a hole in the viral infected cells
Granzymes from NK cell enters the perforin hole and activates apoptosis in virus infected cells
Cell dies by apoptosis
Macrophage engulfs the dying cell
What are the 3 signals required in order to activate a lymphocyte?
- Recognition of Antigen by T lymphocytes
- APCs binding to the T cell
- Cytokines provide the final activation signal
_____ is an important bridge between innate and adaptive immunity?
Pattern Recognition Receptors (PRRs)
Describe the process of how the innate immune system bridges to the adaptive immune system.
PRRs activate APCs
APCs process Ags and present them to naive T cells
Secreted cytokines assist the development and maturation of T cells
Which TLRs have the ligand for gram positive LPS?
TLR1, 2, 6
Which TLRs have the ligand for ds viral RNA?
TLR3
Which TLRs have the ligand for gram negative LPS?
TLR4
Which TLRs have the ligand for Unmethylated CpG DNA?
TLR9
