Immunity to Infection

Question 1

Mycobacterium tuberculosis requires which type of immune response to promote clearance due to its intracellular niche?

Answer 1

Th1 cell activation

Question 2

What properties of the skin make it inhospitable to microorganisms?

Answer 2

Low moisture, high acidity of sweat

Question 3

Name two pathogens with high acid tolerance that can take residence on the skin

Answer 3

Staph epidermis and staph aureus

Question 4

What is lysozyme?

Answer 4

Potent antimicrobial released in saliva and tears

Question 5

How does lysozyme work?

Answer 5

Lysozyme degrades the peptidoglycan layer that is unique to bacterial surfaces and is required for their survival.

Lysozyme is effective against both gram positive and gram negative bacteria

Question 6

What cells secrete antimicrobial peptides?

Answer 6

AMPs are secreted by epithelial cells and phagocytes

Question 7

Defensins and cathelicidens are AMPs that act on what types of pathogens

Answer 7

The AMPs defensins and cathelicidins can act broadly on bacteria, fungi and viruses

Question 8

The AMP histatin acts on what type of pathogens?

Answer 8

Fungi

Question 9

What type of pathogen is cryptococcus neoformans?

Answer 9

Cryptococcus neoformans is a fungus

Question 10

TLR2 is binds to what PAMPS?

Answer 10

TLR2 binds to lipoteichoic acid and lipoproteins of both gram positive and gram negative bacteria

Question 11

TLR4 is effective at binding what?

Answer 11

lipopolysaccharides (LPS), a signature of gram negative bacteria

Question 12

TRL3 is effective at binding what PAMP?

Answer 12

TLR3 binds to dsRNA - good against viral infections

Question 13

TLR5 is effective at binding what PAMP?

Answer 13

TLR5 recognizes the flagellin- good against bacteria

Question 14

What does TLR9 bind?

Answer 14

TLR9 recognizes both bacterial and viral DNA

Question 15

What is TLR7/8 responsible for recognizing?

Answer 15

TLR7/8 binds to ssRNA - good against viral infections

Question 16

What are NOD-like receptors necessary for recognizing?

Answer 16

NOD-like receptors are important for the recognition of intracellular bacteria

Question 17

Listeria and mycobacterium are what type of pathogens?

Answer 17

Intracellular bacteria

Question 18

What does NOD1 recognize?

Answer 18

Peptidoglycan breakdown products of gram negative bacteria that reach the cytosol

Question 19

Give an example of a pathogen recognized by NOD1 receptors

Answer 19

Salmonella

Question 20

What pathogens are recognized by NOD2 receptors?

Answer 20

Gram positive and gram negative bacteria, and mycobacterium tuberculosis

Question 21

Is what tissue is NOD2 enriched?

Answer 21

THe gut

Question 22

Some Crohn’s disease patients have mutations in which receptors?

Answer 22

NOD2

Question 23

What is the glucan receptor important for?

Answer 23

Glucan receptor recognizes beta-glucans that comprise fungal cell walls

Question 24

What do scavenger receptors recognize?

Answer 24

bacterial cell wall components

Question 25

All PAMP receptor pathways converge onto what killing mechanism?

Answer 25

Respiratory burst and killing of the pathogen

Question 26

MAC complex formation is more effective in killing what type of bacteria?

Answer 26

Gram negative bacteria Gram positive bacteria and fungi are resistant to MAC formation

Question 27

How effective is opsonization against various pathogens?

Answer 27

Opsonization with C3 and recognition by the C3R can effectively opsonize gram positive AND gram negative bacteria, along with most other foreign pathogens

Question 28

Chronic granulomatous disease, a defective NADPH oxidase complex leads to what problems?

Answer 28

NADPH is involved in respiratory burst (the final pathway of PAMPS). Defect leads to significant susceptibility to bacterial and fungal infections

Question 29

Viral single-stranded (TLR7) and double stranded RNA (TLR3) is recognized by TLRs leading to the induction of what?

Answer 29

Type 1 interferons Type 1 interferons are induced by virally infected cells

Question 30

How do type 1 interferons provide protection against viruses?

Answer 30

Type 1 interferons induce Interferon Stimulated Genes (ISGs) that prevent viral synthesis and contain viral spread they also increase MHC Class I, the TMMI response, and NK cell activation

Question 31

How do type 1 and type 2 interferons differ?

Answer 31

Type 1 interferon: alpha and beta Type 2 interferon: gamma Type 1 are specific to antiviral immunity Type 2 are induced in response to both bacterial and viral pathogens

Question 32

What leukocyte spikes following the production of interferon alpha/beta?

Answer 32

NK cells! NK cells are a major player in the destruction of virally infected cells

Question 33

How does staphylococcus aureus evade antibody binding?

Answer 33

Staphylococcus aureus produces toxins that can perturb antibody binding (Protein A)

Question 34

Name three bacteria that are resistant to opsonization due to the production of capsular polysaccharides that interfere with C3 recognition

Answer 34

Streptococcus pneumonia, Group A streptococcus, and staphylococcus aureus

Question 35

Which antibody class is particularly necessary in the fight against parasites?

Answer 35

IgE- they bind to eosinophils via their Fc regions and induce eosinophil-dependent killing