Lecture 23 (Evasion of the Immune Response by Pathogens) Flashcards
bacteria can interfere with TLR signaling pathways in many different ways and at many different positions. this can include redirecting the signaling pathways from ______________ to ________________ pathways
pro-inflammatory to anti-inflammatory
__________ is a protein complex that controls transcription of DNA, cytokine production, and cell survival
NF-kB
IL-10
a) pro-inflammatory cytokine
b) anti-inflammatory cytokine
b) anti-inflammatory cytokine
IL-1, IL-6, TNFα
a) pro-inflammatory cytokines
b) anti-inflammatory cytokines
a) pro-inflammatory cytokines
Brucella synthesizes a protein called ________ that closely resembles the mammalian Toll/IL-1 receptor
TcpB
Brucella synthesizes a protein called TcpB. as a result, it causes accelerated ______________ of an adaptor protein and blocks the _______ signaling pathway
degradation; TLR
a mitogen-activated protein kinase is a type of protein kinase that is specific to the amino acids ___________ and _________
serine and threonine
____________ are involved in directing cellular responses to a diverse array of stimuli, such as mitogens, osmotic stress, heat shock, and pro-inflammatory cytokines
MAPKs
impairs the regulation
a) P. aeruginosa
b) B. anthracis
c) Shigella spp.
d) Yersinia spp.
a) P. aeruginosa
proteolysis of MKK
a) P. aeruginosa
b) B. anthracis
c) Shigella spp.
d) Yersinia spp
b) B. anthracis
elimination of MAPK
a) P. aeruginosa
b) B. anthracis
c) Shigella spp.
d) Yersinia spp.
c) Shigella spp.
acetylation of MAPK
a) P. aeruginosa
b) B. anthracis
c) Shigella spp.
d) Yersinia spp.
d) Yersinia spp.
misdirection of signaling pathways occurs when products from Candida, Yersinia, or Mycobacteria trigger signaling through TLR2, leading to production of ____________
IL-10
Staphylokinase from S. aureus can bind and…
a) neutralize defensins
b) destroy cathelicidins
c) decrease defensin activity d) block β-defensin expression by airway epithelial cells
a) neutralize defensins
Staphylococcal enzyme aureolysin…
a) neutralizes defensins
b) destroys cathelicidins
c) decreases defensin activity
d) blocks β-defensin expression by airway epithelial cell
b) destroys cathelicidins
Salmonella can bind and….
a) neutralize defensins
b) destroy cathelicidins
c) decrease defensin activity d) block β-defensin expression by airway epithelial cells
c) decrease defensin activity
Klebsiella pneumoniae capsular polysaccharide…
a) neutralizes defensins
b) destroys cathelicidins
c) decreases defensin activity
d) blocks β-defensin expression by airway epithelial cells
d) blocks β-defensin expression by airway epithelial cells
S. aureus inhibits phagocytosis by expressing ______________, which binds to Fc portion of IgG, so it prevents antibodies to bind to the Fc receptor on phagocytic cells or activating the classical complement pathway
Protein A
encapsulated bacteria such as Pneumococci possess a thick ______________ capsule that phagocytes find difficult to bind
hydrophilic
Streptococci produce M protein which can bind ___________ and masks C3b-binding sites
fibrinogen
M protein also binds factor H, inactivating bound _______
C3b
several gram-negative bacteria of veterinary importance, such as Mannheimia hemolytica and Fusobacterium necrophorum, secrete _____________ that kill leukocytes, especially granulocytes
leukotoxins
the most important leukotoxins are the ___________ proteins
RTX (“repeats in toxin”)
M. hemolytica secretes a __________ toxin that kills ruminant neutrophils, alveolar macrophages, and lymphocytes
RTX
gram-negative bacteria such as Salmonella, Pseudomonas species, and E. coli have developed an elaborate needle complex – a _________ ___ _____________ system – to convey effector molecules directly into the cytosol of the effector cells
type III secretion system
L. monocytogenes is taken up by induced phagocytosis, which is thought to be mediated by a membrane associated protein called ________________
internalin
_____________ ___________ is an important mechanism used by pathogenic microorganisms for escaping the neutralizing activities of antibodies
antigenic variation
the “relapses” of relapsing fever caused by spirochete, __________ ___________, are a result of antigenic variation by the organism
Borrelia recurrentis
________ viruses have a small genome, so they don’t have room to accommodate genes dedicated to suppressing immunity
RNA
RNA virus proteins are multifunctional and they tend to rely on __________ _________ for immune evasion
antigenic variation
_____ viruses have a larger genome and can afford to devote many different genes to immune evasion
DNA
in larger DNA viruses, up to half of the total genome may be devoted to ___________________ genes
immunoregulatory
some viruses (human Hepatitis C) block the effect of _________ by making soluble receptors of interferons or by blocking the activities of IL-12 and IL-18
IFNγ
some viruses make their own version of cytokines and chemokines, these are called ___________ or __________ // these interfere with the normal functioning of host cytokines
virokines or immunoevasins
immunoevasins are produced by viruses that interfere with the processing of antigens that bind to [MHC I/MHC II] class molecules
MHC I
viruses down regulate MHC class I expression to escape detection by T cells, but they still can be detected by _______ cells
NK cells
gradual change in the antigenicity of a virus as a result of mutations and selection
a) antigenic drift
b) antigenic shift
a) antigenic drift
a sudden, major genetic change in which a new strain develops as a result of recombination between two virus strains
a) antigenic drift
b) antigenic shift
b) antigenic shift
examples of viruses that infect lymphocytes and either kill them or impair their ability to function normally
-HIV
-FIV
-canine distemper virus
-feline leukemia virus
a state of reversible nonproductive infection is called _________
latency
latency is a consistent feature of what virus?
herpesviruses
t/f: during latency, a small number of viral genes are expressed and are not detected by the immune system
true
M. hemolytica and BHV-1 acting together, cause severe respiratory disease in ___________
cattle
BHV-1 infection [decreases/increases] expression of an integrin on lung neutrophils
increases
what do immunoevasins/virokines do?
a) down regulate MHC I expression
b) allow for possible new host compatibility
c) interfere in host cytokines causing suppression of the immune response
c) interfere in host cytokines causing suppression of the immune response
match the example pathogen with how it interferes with the TLR signaling pathway: Leptospira
a) modify PAMPs to not be recognized
b) accelerate destruction of intermediate signals via TcpB
c) destroy MAPK so transcription factors never turned on
d) redirects cytokines synthesis to IL-10 rather than inflammatory
a) modify PAMPs to not be recognized
match the example pathogen with how it interferes with the TLR signaling pathway: Brucella
a) modify PAMPs to not be recognized
b) Accelerate destruction of intermediate signals via TcpB
c) Destroy MAPK so transcription factors never turned on
D) Redirects cytokines synthesis to IL-10 rather than inflammatory
b) Accelerate destruction of intermediate signals via TcpB
match the example pathogen with how it interferes with the TLR signaling pathway: Shigella spp. and Yersina spp.
a) modify PAMPs to not be recognized
b) Accelerate destruction of intermediate signals via TcpB
c) Destroy MAPK so transcription factors never turned on
D) Redirects cytokines synthesis to IL-10 rather than inflammatory
c) Destroy MAPK so transcription factors never turned on
match the example pathogen with how it interferes with the TLR signaling pathway: Candida sp, Yersina sp. and Mycobacteria sp.
a) modify PAMPs to not be recognized
b) accelerate destruction of intermediate signals via TcpB
c) destroy MAPK so transcription factors never turned on
d) redirects cytokines synthesis to IL-10 rather than inflammatory
d) redirects cytokines synthesis to IL-10 rather than inflammatory
what mechanism to avoid being phagocytosed is utilized by: Staph aureaus
a) Protein A, which competitively binds the Fc portion of Ab
b) thick hydrophilic capsule
c) M protein to avoid opsonization
d) Factor H binding to mask C3b and block MAC
e) Type III secretion system (injection of modulators)
f) kill the phagocytes w/ leukotoxins
a) Protein A, which competitively binds the Fc portion of Ab
what mechanism to avoid being phagocytosed is utilized by: Pneumococci
a) Protein A, which competitively binds the Fc portion of Ab
b) thick hydrophilic capsule
c) M protein to avoid opsonization
d) Factor H binding to mask C3b and block MAC
e) Type III secretion system (injection of modulators)
f) kill the phagocytes w/ leukotoxins
b) thick hydrophilic capsule
what mechanism to avoid being phagocytosed is utilized by: Streptococci
a) Protein A, which competitively binds the Fc portion of Ab
b) thick hydrophilic capsule
c) M protein to avoid opsonization
d) Factor H binding to mask C3b and block MAC
e) Type III secretion system (injection of modulators)
f) kill the phagocytes w/ leukotoxins
c) M protein to avoid opsonization
what mechanism to avoid being phagocytosed is utilized by: Borrelia burgdorferi and Leptospira
a) Protein A, which competitively binds the Fc portion of Ab
b) thick hydrophilic capsule
c) M protein to avoid opsonization
d) Factor H binding to mask C3b and block MAC
e) Type III secretion system (injection of modulators)
f) kill the phagocytes w/ leukotoxins
d) Factor H binding to mask C3b and block MAC
what mechanism to avoid being phagocytosed is utilized by: Salmonella, E.coli, and Pseudomonas
a) Protein A, which competitively binds the Fc portion of Ab
b) thick hydrophilic capsule
c) M protein to avoid opsonization
d) Factor H binding to mask C3b and block MAC
e) Type III secretion system (injection of modulators)
f) kill the phagocytes w/ leukotoxins
e) Type III secretion system (injection of modulators)
what mechanism to avoid being phagocytosed is utilized by: Mannheimia hemolytica and Fusobacterium necrophorum
a) Protein A, which competitively binds the Fc portion of Ab
b) thick hydrophilic capsule
c) M protein to avoid opsonization
d) Factor H binding to mask C3b and block MAC
e) Type III secretion system (injection of modulators)
f) kill the phagocytes w/ leukotoxins
f) kill the phagocytes w/ leukotoxins
Listeria monocytogenes is taken up into even non-phagocytic cells and this is mediated by what?
Internalin
once ingested, Listeria monocytogenes produces what that allows it to escape the phagosome?
Listeriolysin (LLO)
what immune evasion mechanism is utilized by human hepatitis C?
a) virokines/immunoevasins
b) block expression of MHC I
c) decrease MICB expression
d) alter T cell function specifically
a) virokines/immunoevasins
HIV, FIV, and FeLV combat the immune system by:
a) infecting lymphocytes and impairing their ability to function
b) using a period of latency to hide then recrudescing when system is stressed
c) producing enzymes that inhibit apoptosis
a) infecting lymphocytes and impairing their ability to function
Herpesviruses combat the immune system by:
a) infecting lymphocytes and impairing their ability to function
b) using a period of latency to hide then recrudescing when system is stressed
c) producing enzymes that inhibit apoptosis
b) using a period of latency to hide then recrudescing when system is stressed
and
c) producing enzymes that inhibit apoptosis
Pox viruses combat the immune system by:
a) infecting lymphocytes and impairing their ability to function
b) using a period of latency to hide then recrudescing when system is stressed
c) producing enzymes that inhibit apoptosis
c) producing enzymes that inhibit apoptosis
the break out of K9 influenza (2015 in US for example) ties back to:
a) antigenic drift
b) antigenic shift
b) antigenic shift
Salmonella enterica utilizes which strategy to avoid our immune system:
a) antigenic variation
b) antigenic diversity
b) antigenic diversity
Streptococcus pyogenes utilizes which strategy to avoid our immune system:
a) antigenic variation
b) antigenic diversity
b) antigenic diversity
Streptococcus pneumoniae utilizes which strategy to avoid our immune system:
a) antigenic variation
b) antigenic diversity
b) antigenic diversity
Borrelia recurrentis utilizes which strategy to avoid our immune system:
a) antigenic variation
b) antigenic diversity
a) antigenic variation
Trypanosomes utilizes which strategy to avoid our immune system:
a) Antigenic Variation
b) Antigenic Diversity
a) Antigenic Variation
what two organisms work synergistically to cause Bovine Respiratory Disease (BRD)?
-virus: Bovine Herpesvirus 1 (BHV-1)
-bacteria: Mannheimia hemolytica (M. hemolytica)
