Breakout Session 1 Flashcards
Cells of the innate immune system are limited in their recognition of foreign molecules
to ________
Pathogen-associated molecular patterns (PAMPs)
What are PAMP receptors are known as?
Pattern recognition receptors (PRRs)
What three rule should PAMP’s follow?
1) NOT found naturally in the host
2) Conserved over a large number of organisms
3) Essential for survival for the microorganism
True or False: Lipopolysaccharide (LPS) , Lipoteichoic acid (LTA), Peptidoglycan (PGN), and Lipoproteins are examples of
PAMP’s on a bacterial pathogen
True
True or False: C-type lectin receptors, Nucleotide-binding oligomerization domain (NOD) and Toll-like receptors (TLRs) are examples of PRR’s located on the host cell
True
What type of carbohydrate structure do CLRs (C-Type Lectin Receptors) recognize: intracellular or extracellular?
Extracellular
What type of receptor protects against fungal and mycobacteria pathogens?
C-Type Lectin Receptors
Which transcription factor do all the members of the C-Type Lectin receptor family activate?
NF-kB
As a result of the C-Type Lectin receptor, NF-kB is activated.
What cytokine is produced?
What cell type is activated?
-IL-17 production (cytokine)
-Th17 cells
What type of PAMP’s do NLRs recognize?
Intracellular PAMP’s
Which receptor is most likely to recognize bacterial peptidoglycan and dsRNA from viruses and fungi?
A. C-Type Lectin
B. NLR
C.
D.
Which receptors is involved in the formation of inflammasomes?
NLR’s
____: cytoplasmic
multiprotein oligomers consisting of PRRs, caspase 1, PYCARD, NALP and
sometimes caspase 5.
Inflammasomes
Where are inflammasomes expressed?
Myeloid cells
-They are a component
of the innate immune system.
True or False: Do inflammasomes act as transcription
factors to induce cytokine production?
False
What molecules stimulate the maturation of inflammatory cytokines (IL-1-β and IL-18) to promote the inflammatory response
against bacteria, fungi and viruses?
Inflammasomes
What type of PAMP’s do RIG-I family members recognize?
Intracellular cytoplasmic
Of the following, which are most important for initiating the innate immune response against RNA viruses?
A. TLR’s
B. RIG-I
C. CLR’s
D. NLR’s
B. RIG-I
Of the following, which activates IRF-3 ?
A. TLR’s
B. RIG-I
C. CLR’s
D. NLR’s
B. RIG-I
As a result of RIG-I, IRF-3 is activated. What two molecules are produced following this?
A. INF-alpha/INF-beta (anti-viral Type I
B. NF-Kb
C. All of the above
C. All of the above
____enhance the production of pro-inflammatory cytokines
NF-Kb
Where are TLRs primarily expressed? What molecule do they use for signaling?
Antigen presenting cells (macrophages, DC, and B cells)
NF-kB
Individual TLRs selectively recruit adaptor molecules such as ____ which provide specific immunologic responses.
MyD88
True or False: TLRs function as pentamers and have an ectodomain which is arginine-rich, horseshoe shaped, and are
involved in binding to PAMPs.
False - TLRs function as dimers
and have an ectodomain which is leucine-rich, horseshoe shaped, and are
involved in binding to PAMPs
True or False: TLR’s have a 150 amino acid intracytoplasmic
domain that is homologous to the IL-1 receptor and is involved in signaling
True
What type of PAMP’s do TLRs recognize? Examples?
- Extracellular PAMP’s
(TLR 2-1, 2-2, 2-6
TLR4 and TLR5) - Intracellular vesicular receptors (inside ER, endosomes, lysosomes)
(TLR3,7,8,9)
What type of PAMP’s do cell surface TLRs identify?
Extracellular PAMPs
on Gram-negative and positive bacteria, fungi, and parasites
Which TLR binds triacyl lipopeptides found on bacteria?
A. TLR2-1
B. TLR2-2
C. TLR2-6
D. TLR4
E. TLR5
A. TLR2-1
Which TLR binds peptidoglycan,lipoarabinomannan, phospholipomannan and glycosylphosphatidylinositol?
A. TLR2-1
B. TLR2-2
C. TLR2-6
D. TLR4
E. TLR5
B. TLR2-2
Which TLR binds diacyl lipopeptides, lipoteichoic acid, and zymosan?
A. TLR2-1
B. TLR2-2
C. TLR2-6
D. TLR4
E. TLR5
C. TLR2-6
Which TLR binds lipopolysaccharide from Gram-negative bacteria, fungal mannans, and envelope proteins on respiratory
syncytial virus?
A. TLR2-1
B. TLR2-2
C. TLR2-6
D. TLR4
E. TLR5
D. TLR4
Which TLR binds binds flagellin on bacteria?
A. TLR2-1
B. TLR2-2
C. TLR2-6
D. TLR4
E. TLR5
E. TLR5
What type of genetic information do intracellular vesicular TLRs recognize?
1) genomic RNA
2) DNA found in viruses
3) CpG motifs in bacteria/fungi
____binds ssRNA from West Nile virus and dsRNA from Reovirus
A. TLR4
B. TLR5
C. TLR3
C. TLR3
___ and ___ bind ssRNA found in Influenza virus and vesicular stomatitis virus
A. TLR4 and TLR5
B. TLR3 and TLR2
C. TLR7 and TLR8
C. TLR7 and TLR8
____binds dsDNA found in Herpes simplex virus and CpG motifs found in bacterial and fungal DNA
A. TLR4
B. TLR3
C. TLR7
D. TLR9
D. TLR9
___is the founding member of the TLR family and has been the most studied.
TLR4
Bacterial lipopolysaccharide (LPS)—a ligand for TLR4—contains____, a common
lipid backbone found in all LPS.
lipid A
What two proteins function as LPS carriers?
CD14; LPS binding protein
True or False: MD2 forms a complex with TLR4 on the cell surface and functions as a co-receptor for LPS
True
How does LPS presentation to TLR4 begin?
What occurs after?
When soluble LBP binds LPS
CD14 binds to LBP and delivers LPS to the TLR4/MD2 complex
When two copies of the TLR4/MD2 complex are bound by LPS they initiate signal
transduction through ___ and other signaling molecules, resulting in the
translation of cytokines and other mediators
MyD88
What is the characteristic TLR recognizing Extracellular PAMPs? What is the characteristic TLR recognizing Intracellular PAMPs?
TLR4 ; TLR3
TLR3 functions as a homodimer that binds ___ from phagocytosed viruses (such as RSV) while they are in the endosome.
TLR3 then associates with ___and activates ___to induce Interferon production and ___to induce inflammatory
cytokine production.
dsRNA
TRIF ; IRF3 ; NF-kB
TLRs initiate intracellular signaling through Toll/IL-1 receptor (TIR) domain-
containing adaptor molecules. Examples of adaptor molecules include: ___, ____, ____, and ____.
MyD88, TIRAP, TRIF, and TRAM
True or False: Adaptor molecules are recruited by specific TLRs to activate specific signaling pathways.
True
MyD88 is used by all TLRs except ____
TLR3
What molecule does MyD88 activate to
induce inflammatory cytokines?
NF-kB
Both TLR3 and TLR4 use what molecule?
TRIF
What two molecules does TRIF activate? Effect?
NF-kB and IRF3
-Induces production of both inflammatory cytokines and anti-viral type I interferons.
True or False: The intestinal epithelial cells, like other epithelial cells, express
toll like receptors that can initiate a systemic immune response to promote
inflammation
True
TLRs are virtually absent on the ____ side of epithelial cells of the GI tract. Therefore, TLRs are only stimulated if the bacteria breach the
___ cell layer.
apical; epithelial
If bacteria breach the epithelial layer of the GI tract,
cytosolic Nod-like receptors (NLRs) and Toll like receptors (TLRs) on the basolateral membrane of epithelial cells and on ____ and ____ cells in the lamina propria can be activated.
macrophages; dendritic
True or False: TLR stimulation in the GI tract leads to the
i. Production of factors (e.g., TFF3) that promote motility and repair
of the epithelium
ii. Participation in promoting B cell production of sIgA
iii. Maintenance of tight junctions
iv. Expression of anti-microbial peptides (e.g., defensins)
v. Increase phagocytic ability of dendritic cells and macrophages
without promoting inflammation
True
LR 5 deficiency is associated with:
A. increases in encephalitis due to HSV type 1
B. increased susceptibility to legionella pneumonia
C. increased susceptibility to
pyogenic bacteria and pseudomonas species
B. increased susceptibility to legionella pneumonia
Mutations in MyD88 and IRAK-4 are associated with:
A. increases in encephalitis due to HSV type 1
B. increased susceptibility to legionella pneumonia
C. increased susceptibility to
pyogenic bacteria and pseudomonas species
C. increased susceptibility to
pyogenic bacteria and pseudomonas species
TLR3 deficiency is associated with:
A. increases in encephalitis due to HSV type 1
B. increased susceptibility to legionella pneumonia
C. increased susceptibility to
pyogenic bacteria and pseudomonas species
A. increases in encephalitis due to HSV type 1