Innate Immunity

Question 1

Identify common examples of pathogen infection routes.

Answer 1

Airway, GI tract, Reproductive tract, External surfaces, Wounds/ abrasions, Insect bites

Question 2

The complement system, use of cytokines like interferons, inflammation and a fever, are examples of a _________ lines of defense of the body.

Answer 2

Secondary

Question 3

The first line of defense against pathogens would be -?

Answer 3

The skin, mucous membranes, and chemicals

Question 4

While non-specific and quick acting, there are only a few examples of memory production. What immunity is being referred to?

Answer 4

Innate immunity

Question 5

If an innate immune response can be activated within the first 4 hours of initial infection, how long would an adaptive immune response take to begin?

Answer 5

Over 96 hours, or 4 days

Question 6

What apparatus within the respiratory tract is crucial for the elimination of pathogens and preventing their entry?

Answer 6

The mucociliary apparatus

Question 7

Which of the following is true?
A) Fatty acids and an increased proton concentration have bactericidal effects
B) Surfactant material produced by Type II pneumocytes contain opsonins
C) A washing effect is achieved by the tears and saliva, which contain crucial enzymes for pathogen degradation
D) Normal microbiota secrete inhibitory substances to inhibit the growth of pathogens
E) Two of the above
F) Three of the above

Answer 7

F) Three of the above (B, C, and D)

Fatty acids found in sweat only inhibit bacterial growth

Question 8

What common characteristic is shared between the skin, gut, lungs, eyes, and nose?

Answer 8

Cells contain tight junctions limiting the movement of pathogens paracellularly

Question 9

The ________ system is the most important humoral factor of innate immunity.

Answer 9

Complement

Question 10

T/F: Associated with coagulation, thrombocytes are capable of secreting beta-lysine, which has bactericidal effects against Gram Negative bacteria.

Answer 10

False, against Gram Positive bacteria

Question 11

________ and ______ are responsible for iron sequestering from bacterial pathogens, while _______ has capabilities to breakdown the mucopeptides of the bacterial cell wall.

Answer 11

Lactoferrin and Transferrin

Lysozyme

Question 12

Interleukin 1 is associated with what two conditions?

Answer 12

Fever and the induction of acute phase proteins

Question 13

What cytokines can be secreted to inhibit the growth and replication of viruses extracellularly?

Answer 13

None, viruses are obligate intracellular pathogens

Question 14

What two cells are considered “professional” phagocytes?

Answer 14

Neutrophils and macrophages

Question 15

What cells are identified solely by the expression of CD66 on their cells surface?

Answer 15

Neutrofiles

Question 16

What granules are present with Neurtrophils?

Answer 16

Azurophilic and Secondary granules

Question 17

While lysozyme can be found in both azurophilic and secondary granules, what other molecules are present within azurophilic granules?

Answer 17

Defensins (inhibit bact. growth), Proteolytic enzymes (degrade bact. proteins), and Myeloperoxidase (req. for bactericidal substances)

Question 18

What is the purpose for myeloperoxidase?

Answer 18

To produce bactericidal substances like HClO^(-) (hypochlorous acid) due to the fusion of a chloride anion and hydrogen peroxide

Question 19

What is the purpose of NADPH oxidase?

Answer 19

For the production of toxic radicals

Question 20

What markers are associated for the differentiation of macrophages from other cells?

Answer 20

CD14, CD11b, F4/80

Question 21

What signal or stimulation is needed for Macrophages to be activated for phagocytic degradation of pathogens?

Answer 21

SOS or Danger signals, which are produced at the area of pathogen entry, etc.

Question 22

What 4 examples are given in lecture, which represent SOS signals?

Answer 22

N-formyl-methionine, peptides, complement system, and cytokines

Question 23

What danger signal is produced by bacterium upon entry and infection within host tissues?

Answer 23

N-formyl-methionine, which initiates protein synthesis in bacterium

Question 24

What function do SOS signals have for macrophages?

Answer 24

Chemotactic roles

Question 25

Where are Fc receptors found, and what do they bind to?

Answer 25

Fc receptors are found on macrophages, and they bind to Fc binding sites of antibodies (bound to an antigen)

Question 26

Within the complement system, what component is needed to bind to an antigen to later bind to a phagocyte?

Answer 26

C3b complement, which then binds to a receptor of the phagocyte

Question 27

SRA, CD68, Lox-1 and CD36, are all examples of macrophage receptors that bind to various polyamines found on bacterial surfaces. What types of receptors are these?

Answer 27

Scavenger receptors

Question 28

TLRs respond following the recognition of ______________________________, which stimulates macrophages to bind to antigens and secrete cytokines.

Answer 28

Pathogen Associated Molecular Patterns (PAMPs)

Question 29

Within the innate response, following the secretion of cytokines, such as IL-1, TNF alpha, and IL-6, what will occur?

Answer 29

Inflammation

Question 30

Following the endocytosis of a pathogen, what will occur?

Answer 30

The enclosed pathogen in the phagosome will then fuse with a lysosome (now called a phagolysosome), which lead to its intracellular degradation

Question 31

What occurs to the degraded material following phagocytosis?

Answer 31

Exocytosis of degraded contents, production of MHC complexes

Question 32

What cells are capable of oxidative and non-oxidative mechanisms of pathogenic degradation via phagocytosis?

Answer 32

Neutrophils, Monocytes, and Macrophages

Question 33

In order for respiratory burst to occur, what two molecules are needed?

Answer 33

Glucose and Oxygen

Question 34

Which of the following does not occur during respiratory burst? A) Glucose is metabolised to form NADPH through the pentose-phosphate pathway B) Cytochrome peroxidases activates NADPH to react with oxygen to form a superoxide anion C) NADPH activates oxygen to produce a superoxide anion to reduce hydrogen peroxide into more oxygen D) Superoxide anion reacts with hydrogen peroxide to form hydroxyl radicals and ions

Answer 34

B) Cytochrome [oxidases] activates NADPH to react with oxygen to form a superoxide anion

Question 35

While a superoxide anion can react with hydrogen peroxide, what else can it react with and form?

Answer 35

It can react with nitric oxide to produce peroxynite (ONOO^(-)), a reactive nitrogen species

Question 36

What will form if nitric oxide were not reacted with superoxide anion, and only oxidized?

Answer 36

The formation of reactive nitrogen species nitrogen dioxide (NO2)

Question 37

______ (a cytokine) is used in the formation of iNOS, nitric oxide synthase, which will produce ________ from L-arginine.

Answer 37

TNF alpha | Nitric oxide

Question 38

What cytokines are associated with the production of iNOS?

Answer 38

TNF alpha and IFN gamma

Question 39

What role do cationic proteins have, and what organelle are they located in?

Answer 39

Located within lysosomes, they damage the bacterial cell wall

Question 40

Host sentinel cells, like macrophages, dendritic cells, and mast cells, are able to sense what two types of molecules?

Answer 40

PAMPs and DAMPs

Question 41

What is the difference between PAMPs and DAMPs?

Answer 41

DAMPs are endogenous molecules that are released from damaged cells, whereas PAMPs are molecules are repetitive motifs found on pathogens and not on host cells

Question 42

What receptors are responsible for recognition of PAMPs and DAMPs?

Answer 42

PRRs or Pattern Recognition Receptors

Question 43

TLRs, NLRs, RLRs, CLRs, and PRGPs, are all examples of PRRs. Which of the following are the major receptors found both intracellularly and extracellularly?

Answer 43

TLRs, or Toll-like receptors

Question 44

While TLR3 are associated with ____________ viruses, TLR7 and TLR8 are associated with ___________ viruses.

Answer 44

TLR 3 = dsRNA viruses | TLR 7/8 = ssRNA viruses

Question 45

What is recognized by TLR9?

Answer 45

Bacterial DNA and some herpesviruses

Question 46

``` Which of the following TLRs would not be activated by the MyD88? A) TLR3 B) TLR7 C) TLR9 D) TLR12` ```

Answer 46

A) TLR3 | This TLR is activated via TRIF

Question 47

T/F: The result of the activation of TLRs is the synthesis of proinflammatory cytokines.

Answer 47

True

Question 48

TLRs, NLRs, RLRs, CLRs, and PRGPs, are all examples of PRRs. Which of the following are the major receptors found only intracellularly, and sense intracellular bacteria in the cytoplasm?

Answer 48

NLRs, Nod-like receptors

Question 49

NOD1 and NOD2 receptors are associated with the activation of what transcription factor?

Answer 49

NF-kB, which transcribes and translates for proinflammatory cytokines

Question 50

How are NOD1 and NOD2 differentiated based on their recognition of intracellular bacteria?

Answer 50

``` NOD1 = Peptidoglycans NOD2 = Muramyl peptides ```

Question 51

T/F: NLRs are unable to be stimulated by DAMPs.

Answer 51

False, they can be

Question 52

Interferon regulatory factors 3 and 7 are associated with the production of what type of interferons?

Answer 52

Type 1 Interferons

Question 53

TLRs, NLRs, RLRs, CLRs, and PRGPs, are all examples of PRRs. Which of the following are associated with viral RNA detection in the cytoplasm, and the production of antiviral and inflammatory cytokines?

Answer 53

RLRs, or RIG-like receptors aka Retinoic acid inducible gene-like receptors

Question 54

TLRs, NLRs, RLRs, CLRs, and PRGPs, are all examples of PRRs. Which of the following are associated with fungal pathogens as they bind to their carbohydrates?

Answer 54

CLRs, or C-type Lectin receptors

Question 55

While produced on most cell types, what two antigen presenting cells are associated with this cell receptor?

Answer 55

Macrophages and dendritic cells

Question 56

TLRs, NLRs, RLRs, CLRs, and PRGPs, are all examples of PRRs. Which of the following are associated with detecting peptidoglycans on the surface of Gram positive and negative bacterium, as these receptors are located in granules of neutrophils?

Answer 56

PGRPs, or Peptidoglycan-recognition proteins

Question 57

If a bacterium is detected by PGRP, this will lead to the synthesis of -?

Answer 57

Defensins (bactericidal functions)

Question 58

In what species, will PGRPs be produce exclusively in the skin, bone marrow, and intestines?

Answer 58

Porcine, swine, pigs, etc.

Question 59

LPS, lipoteichoic acid, and polymers of N-acetylglucosamine and N-acetylmuraminic acid, are detected by what PRRs?

Answer 59

PGRPs, or Peptidoglycan-recognition proteins

Question 60

What is the acute phase response?

Answer 60

The increase or decrease of serum proteins, based on the synthesis of TNF alpha, IL-1, and IL-6, which are proinflammatory cytokines

Question 61

T/F: The majority of the acute phase proteins are synthesized by the liver.

Answer 61

True

Question 62

While the end result of the acute phase proteins leads to activating the complement system, they can also be considered -?

Answer 62

CRPs, or C-reactive proteins

Question 63

The ligands for the CRPs are bacterial pneumococcal ____________ and ____________, which will promote phagocytosis and activating the complement system.

Answer 63

Polysaccharides and Phosphorylcholine

Question 64

T/F: Mannose-binding lectin is an acute phase protein, which recognizes mannose on bacterial surfaces.

Answer 64

True

Question 65

In what method do both CRPs and MBL proteins have on bacterium?

Answer 65

Opsonization