Lecture 2 - Innate Immunity Flashcards
Function of lysozyme
Degrade peptidoglycan
Which type of bacteria is lysozyme particularly effective against?
Gram +
Which type of bacteria is lysozyme less effective against?
Gram -
Auxillary cells
1)
2)
3)
1) Megakaryocyte
2) Basophil
3) Mast cell
Phagocytic cells
1)
2)
3)
1) Monocyte/Macrophage
2) Neutrophil
3) Dendritic cell
Difference between macrophages and monocytes
Monocytes citculate in the blood
Macrophages reside in tissues
What do RIG-like helicases detect?
dsRNA
What do NOD-like receptors detect?
Peptidoglycan
What does TLR4 detect?
Lipopolysaccharide
What detects lipopolysaccharide?
TLR4
What detects peptidoglycan?
NOD-like receptor
What detects surface proteins?
1)
2)
1) TLR1/TLR2 complex
2) TLR2/TLR6 complex
What detects dsRNA?
TLR-3, RIG-like helicase
What does TLR-3 detect?
dsRNA
What do TLR-7 and TLR-8 detect?
ssRNA
What detects ssRNA?
TLR-7 and TLR-8
What detects CpG DNA?
TLR-9
What does TLR-9 detect?
CpG DNA
What does TLR-5 detect?
Flagellin
What detects flagellin?
TLR-5
What detects uropathogenic bacteria?
TLR-11
What does TLR-11 detect?
Uropathogenic bacteria
Where is TLR-5 expressed?
Basolateral surface of epithelial cells
Which toll-like receptors are expressed within an endosome?
TLR-3
TLR-7
TLR-9
What is NLRP?
Nod-like receptor family with N-terminal PYD domain
What makes up an inflammosome complex?
Nod-like receptor, PYHIN
What do inflammosomes do?
Activate pro-caspase1
Function of NLR domain in NLRP
Sensor domain
Function of NACHT domain in NLRP
Oligomerisation domain.
Binds to other proteins when activated
Function of PYD domain in NLRP
Signal transduction
Caspase recruitment
Function of ASC domain in NLRP
Adaptor protein
Recruits pro-caspase 1
What does activated caspase 1 do?
1) Converts pro-IL-1b to IL-1b
2) Activates IL-18
Function of IL-1b
Inflammatory mediator
Function of IL-18
With IL-12 promotes IFN-gamma production
Effect of NLRP4/NAIP activation
1) Pyroptosis
2) Eicosanoid production
3) Cytokine processing
What results in NLRP3 activation? 1) 2) 3) 4)
1) Pore-forming toxins
2) Ionophoric compounds
3) High extracellular [Ca] or [ATP]
4) E. coli or V. cholerae
Results of NLRP3 activation
1) Pyroptosis
2) IL-1b, IL-18 release
3) Increase macrophage phagocytosis and digestion
What do inflammasomes sense?
Microbes in cytoplasm
DAMPS
Function of PYD or CARD domain in NLRP
Recruit ASC
Which part of the NLRP recruits ASC?
PYD or CARD domain
What does complement receptor 1 on a macrophage detect?
C3b
What does complement receptor 3 on a macrophage detect?
iC3b
What detects C3b on a macrophage?
Complement receptor 1
What detects iC3b on a macrophage?
Complement receptor 3
What does a C1q receptor on a macrophage detect?
Mannose binding lectin
What on a macrophage detects mannose binding lectin?
C1q
What does a mannan receptor on a macrophage detect?
Glycoconjugates
What on a macrophage detects glycoconjugates?
Mannan receptor
Three ways to activate complement cascade
1) Classical pathway
2) Lectin pathway
3) Alternative pathway
Classical pathway 1) 2) 3) 4) 5) 6) 7)
1) Antibodies activate C1
2) C1 activates C2, C4
3) C3 convertase converts to C3
4) C3b. C3a discarded as an opsonin
5) Formation of C5 convertase C5b. C5a discarded
6) C6, C7, C8, C9
7) Formation of attack complex
Lectin pathway 1) 2) 3) 4) 5) 6)
1) Collectins attached to mannan activate C2 and C4
2) c3 convertase converts to C3
3) C3b. C3a discarded as an opsonin
4) C5 convertase. C5b formed. C5a discarded
5) C6, C7, C8, C9
6) Attack complex formed
Alternative pathway 1) 2) 3) 4) 5) 6)
1) Bacterial surface molecules bind C3b
2) C3 convertase
3) C3b. C3a discarded as opsonin
4) C5 convertase. C5a discarded
5) C6, C7, C8, C9
6) Attack complex formed
Function of C5a
1) Chemotaxis
2) Inflammation
3) B cell activation
Action of complement components 1) 2) 3) 4) 5)
1) Bacterial lysis (C6, C7, C8, C9)
2) Inflammation (C5a)
3) Chemotaxis (C5a)
4) Opsonisation (C3a)
5) Second signal for B cell activation (detected with CR2) (iC3b)
How does C5a contribute to inflammation? 1) 2) 3) 4) 5)
1) Mast cells release histamine
2) Chemoattractant for neutrophils
3) Increase expression of adhesins on endothelial walls
4) Stimulates neutrophils to degranulate
5) fever
What does myeloperoxidase do?
Converts H2O2 to HOCl and water
What are chemokines?
Small, peptide cytokines
Attract cells
Effects of Il-4, IL-10, IL-13
reduce bacterial killing activity
Downregulate TNFalpha
Which cytokines induce neutrophil transmigration? 1) 2) 3) 4)
1) TNFa
2) IL-1
3) IL-8
4) IFNg
What do TNFa, IL-1, IL-8 and IFNg do together?
Induce neutrophil transmigration
What does PAF do?
Vasodilation
What do IL-8 and C5a do?
Chemotaxis
Which cytokines are responsible for chemotaxix?
IL-8, C5a
Which cytokines are responsible for inducing oxidative burst? 1) 2) 3) 4)
1) TNFa
2) IL-1
3) IL-8
4) PAF
What do TNFa, IL-1, IL-8 and PAF do together?
Induce oxidative burst
What does IL-6 do?
Induces liver to release acute phase proteins
–> Complement, transferrin
Which cytokine induces the liver to release acute phase proteins?
IL-6
What systemic effects do IL-1, IL-8 and TNFa have?
Chills, wasting, fever
