Deck 4: Innate Immunity

Question 1

Which of the following is NOT entirely a response of the innate immune system?

A)Phagocytosis by macrophages
B)Protection from infection by the skin
C)Low pH in the stomach
D)Antibody-mediated complement activation
E)Microbial cell lysis by defensin

Answer 1

D

Question 2

A bacterial pathogen has breached the skin barrier of a human.This is the first time this human host has been exposed to this particular pathogen.Which statement is NOT true regarding this situation?

A)Innate immunity will respond to the pathogen more quickly than adaptive immunity.
B)Innate immune cells will utilize PRRs to recognize PAMPs on the pathogen.
C)Normal, intact skin is a good, but not perfect, barrier to pathogen entry.
D)Memory T cells will aid in pathogen recognition and response.
E)Phagocytes within the skin will aid in pathogen recognition and response.

Answer 2

D

Question 3

Which of these characteristics are adaptive?

A)Response takes several days to develop
B)Responds more quickly upon secondary exposure to pathogens
C)Pathogen receptors are extremely varied
D)All of the answers are adaptive characteristics.
E)None of the answers are adaptive characteristics.

Answer 3

E

Question 4

Which of these characteristics are innate?

A)Found in all multicellular plants and animals
B)Receptors are encoded in the germ line
C)Recognizes broad classes of pathogens
D)All of the answers are innate characteristics.
E)None of the answers are innate characteristics.

Question 5

A mixture of S.aureus and the enteric bacteria E.coli was placed onto the skin of the fingertips of a volunteer.The volunteer immediately touched one of their inoculated fingertips to nutrient agar plate #1 and then waited 30 minutes and touched a different inoculated finger to nutrient agar plate #2.After incubating the plates overnight, what pattern of growth would you expect to see on the plates?

A)Both E.coli and S.aureus grew on both plates.
B)Plate #1 grew both, whereas plate #2 grew only S.aureus.
C)Plate #1 grew both, whereas plate #2 grew only E.coli.
D)Plate #1 grew only S.aureus, whereas plate #2 grew both.
E)Plate #1 grew only E.coli, whereas plate #2 grew both.

Question 6

You have discovered a new species of bacteria that lacks peptidoglycan within its cell wall.Based on Table 4-2 (in the text) , which antimicrobial protein or peptide is the species likely to show resistance to?

A)Defensin
B)Lactoferrin
C)Dermcidin
D)Surfactant protein
E)Lysozyme

Question 7

Where would you be LEAST likely to find significant levels of defensins?

A)The lung
B)The intestine
C)The liver
D)The skin
E)The bladder

Question 8

Which of the following is the CORRECT relationship? _____ on _____ recognize _____ on _____.

A)PRRs; macrophages; PAMPs; pathogens
B)PRRs; pathogens; PAMPs; macrophages
C)PAMPs; macrophages; PRRs; pathogens
D)PAMPs; neutrophils; PRRs; pathogens
E)PRRs; macrophages; PAMPs; neutrophils

Question 9

Why are many opsonins multimeric?

A)Because they are all derived from the same proto-opsonin
B)Because they bind repeating structures on pathogen surfaces
C)So that they can be regulated allosterically
D)Because they have to crosslink receptors on phagocytes for phagocytosis to occur
E)Because one subunit binds pathogens, and the other has enzymatic activity

Question 10

Which of the following are associated with damaged or dead cells?

A)Lysophosphatidic acid
B)Altered carbohydrates
C)Low CD47
D)Cell-surface annexin I
E)All of the answers are associated.

Question 11

Which of the following would you predict to result from a mutation in TLR4 that prevents binding to LPS?

A)Increased susceptibility to infection with gram-positive bacteria
B)Decreased susceptibility to septic shock
C)Failure to develop from an embryo
D)Tighter binding between bacteria and macrophages
E)Increased phagocytosis

Question 12

Match the following toll-like receptors with their ligands. $\begin{array}{ll}\text { TLR } & \text { Ligands } \\\hline \text { TLR3 } & \text { Flagellin } \\\text { TLR4 } & \text { Zymosan } \\\text { TLR5 } & \text { dsRNA } \\\text { TLR6 } & \text { CpG unmethylated dinucleotides } \\\text { TLR9 } & \text { LPS }\end{array}$

A)TLR3/LPS; TLR4/CpG unmethylated dinucleotides; TLR5/dsRNA; TLR6/Zymosan; TLR9/Flagellin
B)TLR3/dsRNA; TLR4/LPS; TLR5/Flagellin; TLR6/Zymosan; TLR9/CpG unmethylated dinucleotides
C)TLR3/dsRNA; TLR4/LPS; TLR5/CpG unmethylated dinucleotides; TLR6/Flagellin; TLR9/Zymosan
D)TLR3/CpG unmethylated dinucleotides; TLR4/Zymosan; TLR5/Flagellin; TLR6/LPS; TLR9/dsRNA
E)TLR3/Zymosan; TLR4/LPS; TLR5/Flagellin; TLR6/dsRNA; TLR9/CpG unmethylated dinucleotides

Question 13

A number of strains of the bacteria Salmonella enterica contain flagella and can invade human cells.Based on Figure 4-6, which TLRs are most likely to be used to recognize such strains?

A)TLR4 and TLR 3
B)TLR 4 and TLR 7
C)TLR 5 and TLR 9
D)Only TLR 5
E)Only TLR 7

Question 14

Which of the following is NOT usually induced in response to TLR signaling?

A)TNF- ?
B)IL-1
C)iNOS
D)IL-6
E)IL-4

Question 15

Where would you MOST likely find a TLR that recognizes RNA?

A)On the cell surface
B)In the endosome/lysosome
C)In the nucleus
D)In the mitochondria
E)In the endoplasmic reticulum

Question 16

Which of the following adaptor proteins activate the NF- ? B pathway?

A)MyD88
B)IKK ?
C)Calmodulin
D)IL-2 receptor
E)SOS

Question 17

Which cytokine is known for its antiviral properties?

A)IL-2
B)IL-4
C)IFN- ?
D)TNF- ?
E)IL-1

Question 18

What is the Latin word for "pain"?

A)Rubor
B)Calor
C)Dolor
D)Tumor
E)Accio

Question 19

C-reactive protein is a(n)

A)chemokine.
B)cytokine.
C)acute phase response protein.
D)surfactant.
E)cell-adhesion molecule.

Question 20

How do natural killer cells kill their targets?

A)By lysing them
B)By inducing inflammation
C)By inducing apoptosis
D)By causing them to leave the bloodstream and be trapped by the liver
E)By coating them with opsonins

Question 21

What types of cells are good targets for natural killer cells and why?

A)Bacterial cells because they contain LPS
B)Gram-positive cells because they contain LTA
C)Antigen presenting cells because they have high levels of costimulatory molecules
D)Endothelial cells in inflamed tissues because they have high levels of adhesion molecules
E)Virally infected cells because they have low levels of class I MHC

Question 22

Human cells lining the upper respiratory tract are expressing abnormal levels of surface MHC proteins due to a developing viral infection.Which cell type listed below is MOST likely to recognize the cells as infected based on altered MHC levels?

A)NK cells
B)Macrophages
C)Dendritic cells
D)Helper T cells
E)B cells

Question 23

Predict the clinical outcome of a genetic defect in IRAK4, a protein required for the MyD88 pathway.

A)Increased rates of cancer
B)Increased rates of autoimmune disease
C)Decreased muscle tone
D)Increased rates of bacterial infection
E)Increased TLR signaling

Question 24

Activation of dendritic cells with TLR4 or TLR5 results in the production of _____ that induces differentiation of CD4 T cells into _____.

A)IL-12; T_H1
B)IL-12; T_H2
C)IL-10; T_H1
D)IL-10; T_H2
E)IL-4; T_H1

Question 25

Dendritic cells present _____ antigens on class I MHC through a process known as cross presentation.

A)endogenous
B)exogenous
C)bacterial
D)viral
E)complex

Question 26

Mouse B cells are observed to bind LPS in the laboratory.Based on this observation, which type of innate system-associated molecules are the B cells likely to be expressing that recognize LPS?

A)MHCs
B)Antibodies
C)Chemokines
D)TCRs
E)PRRs

Question 27

Activation of B cells with TLR rather than with T-cell help would result in the overall antibody response being

A)more specific.
B)longer lasting.
C)more polyclonal.
D)reduced.
E)more protective.

Question 28

Which type of vaccine would MOST likely require an adjuvant?

A)Killed bacteria
B)Attenuated virus
C)Inactivated virus
D)Purified protein
E)All of the answers are equally likely.

Question 29

Which of the following defenses is MOST likely to protect a plant from a microbial pathogen?

A)Antibodies
B)CTL
C)Phagocytes
D)Reactive-oxygen species
E)CD4

Question 30

Would a potential vaccine that only activates the innate immune response be likely to be effective? Why or why not?

Question 31

Name three human organs or areas of the body where you would expect to find significant levels of antimicrobial proteins.

Question 32

Using mutagenesis, you have removed a gene essential for production of pili by Escherichia coli known to cause urinary tract infections.Would you expect the mutated bacteria to retain the capacity to cause urinary tract infections?

Question 33

Name a barrier to microbial infection in humans that contains both physical and chemical components.In the example, describe the physical component and chemical component.

Question 34

Why does lysozyme not damage human cells?

Question 35

An innate immune cell has become activated by a PRR-activated signaling pathway.Name the distinct classes of molecules that will be upregulated in response to this type of activation and 1) will put surrounding cells into an "antiviral state" or 2) will attract additional immune cells to the site of activation.

Question 36

A macrophage, using TLR4, has recognized a bacterial pathogen containing LPS.Is this recognition event alone able to trigger phagocytosis? If not, can you name a PRR that can induce phagocytosis after recognition of LPS?

Question 37

How can the regulated cell death of an innate immune cell be beneficial, following activation by PAMPs?

Question 38

How can receptors of the innate immune system, such as PRRs, be considered both specific and general?

Question 39

In no more than five steps, list how an innate immune system could become activated by binding to a Gram-positive bacterial pathogen using TLR2.

Question 40

At what point in evolution did adaptive immunity develop?

Question 41

Imagine you are walking barefoot across a pasture when your foot becomes punctured with a dirty splinter.Describe the physiological and molecular changes that occur in your foot over the next few hours.