Intro to Host Defense

Question 1

What are the characteristics of innate immunity?

Answer 1

Pre-formed Non-specific No Memory Does not improve over time

Question 2

What are the 3 components of innate immunity?

Answer 2

Barriers Cells Antimicrobial Peptides and complement

Question 3

What are the 5 cells of innate defense?

Answer 3

Neutrophils Monocytes Macrophages Dendritic Cells (DC) Natural Killer Cells (NKC)

Question 4

Which cells of the innate defense are non-phagocytic?

Answer 4

Natural Killer Cells

Question 5

What are the characteristics of adaptive immunity?

Answer 5

Slow Onset Highly effective once active Highly specific Memory Improves over time

Question 6

What are the two components of adaptive immunity?

Answer 6

B lymphocytes T lymphocytes

Question 7

Where do B lymphocytes differentiate?

Answer 7

The bone marrow

Question 8

What do B cells produce?

Answer 8

Antibodies or immunoglobulin

Question 9

Where do T cells differentiate?

Answer 9

In the thymus

Question 10

What do T cells produce?

Answer 10

Cytokines of interleukin

Question 11

What does lysozyme degrade?

Answer 11

Peptidoglycans

Question 12

How does skin secrete lysozyme?

Answer 12

Through the sweat glands

Question 13

What are macrophages?

Answer 13

Differentiated forms of monocytes present in the tissues

Question 14

What is this cell?

Answer 14

A Neutrophil

Question 15

What is this cell?

Answer 15

A monocyte

Question 16

What is a DC capable of?

Answer 16

Phagocytosis and pinocytosis

Question 17

What do DCs and macrophages present on their cell surface?

Answer 17

A unique protein antigen called a CD14

Question 18

Are DC’s the most efficient antigen presenting cells?

Answer 18

Why yes they are.

Question 19

How do macrophages and DC’s participate in innate immunity once they phagocytose a microbe?

Answer 19

They destroy the microbes and secrete cytokines

Question 20

How do macrophages and DC’s participate in acquired immunity after phagocytosing a microbe?

Answer 20

They present antigens to CD4-positive helper T cells

Question 21

What fuses during intracellular killing of phagocytosed microbes?

Answer 21

The phagosome containing the microbe with the lysosome

Question 22

What is generated as a result of intracellular killing of phagocytosed microbes?

Answer 22

Reactive nitroge intermediates

Antimicrobial peptides

Reactive oxygen intermediates

Question 23

What does lactoferrin do?

Answer 23

Sequesters iron

Question 24

What are defensins?

Answer 24

Cationic peptides

Question 25

What are alpha-defensins produced by?

Answer 25

Neutrophils and Paneth cells of the stomach

Question 26

What produces beta-defensins?

Answer 26

Epithelial cells in the respiratory tract

Question 27

What are some antimicrobial peptides?

Answer 27

Defensins Lysozyme Lactoferrin

Question 28

The presence of what 3 things can activate complement?

Answer 28

Infection with gram neg bacteria causing release of LPS Infection with fungal or gram pos bacteria causing release of mannose Ag-Ab reactions

Question 29

What components are required for the classical pathway of complement activation?

Answer 29

Ag-Ab complex + C1, C4 and C2 complex

Question 30

What components are required for the alternative pathway for complement activation to start?

Answer 30

Microorganisms' cell wall polysaccharides + Factor B, Factor D and Factor P

Question 31

What do the classical pathway and alternative pathway bring in once started?

Answer 31

C3 which starts the formation of the MAC complex, causes inflammation as well as opsonization?

Question 32

What for of C3 causes opsonization?

Answer 32

C3b

Question 33

What do C3a and C5a cause?

Answer 33

Inflammation

Question 34

What is opsonization?

Answer 34

Coating of the bacterial surface which enhances phagocytosis

Question 35

What components form the MAC complex?

Answer 35

C3b C5b C6 C7 C8 C9

Question 36

How does the MAC complex result in cell lyses?

Answer 36

It inserts itself into the target cell membrane and creates a hole

Question 37

What do NK cells attack and how?

Answer 37

They attack virus-infected body cells by causing the cells to burst by releasing perforin and granulysin

Question 38

What induces NK cells to lyse target cells?

Answer 38

The down regulation of MHC class I

Question 39

What does TLR4 recognize?

Answer 39

LPS

Question 40

What does TLR2 recognize?

Answer 40

Peptidoglycan

Question 41

What 3 steps happen in T cell response?

Answer 41

Antigen recognition Activation Response

Question 42

What do antigens contain?

Answer 42

One or more antigenic determinants also known as epitopes

Question 43

How are haptens different from epitopes?

Answer 43

They are too small to start an inflammatory response

Question 44

What do all T lymphocytes express?

Answer 44

The CD3 antigen

Question 45

In addition to CD3 what doe Cytotoxic T cells express?

Answer 45

CD 8

Question 46

In addition to CD3 what do Helper T cell express?

Answer 46

CD 4

Question 47

What MHC complex do cytotoxic T cells recognize?

Answer 47

MHC I which is a closed ended structure that accomodates peptides of 8-9 amino acids

Question 48

What MHC complex do helper T cells recognize?

Answer 48

MHC II which is an open ended structure that accomodates peptides of 18-20 amino acids.

Question 49

What is IL-4-B

Answer 49

A cell growth factor

Question 50

What is IL-5-B?

Answer 50

A cell differentiation factor

Question 51

What are the 5 classes of antibodies?

Answer 51

IgM, IgG, IgE, IgA, IgD

Question 52

What is IgM?

Answer 52

A pentamer

Question 53

What can IgG travel through?

Answer 53

The placenta

Question 54

What does IgE participate in

Answer 54

Allergic reactions

Question 55

What is IgA secreted in?

Answer 55

Tears and colostrum

Question 56

What is IgD?

Answer 56

A B cell receptor

Question 57

What is LPS considered?

Answer 57

A T-cell independent antigen

Question 58

How do B cells respond to T-cell independent antigens?

Answer 58

They differentiate into plasma cells which releases the IgM antibody

Question 59

What are T cell dependent antigens?

Answer 59

Proteins

Question 60

How do B cells respond to T-cell dependent antigens?

Answer 60

They go through class switching

Question 61

Where is IgG derived from in perinatal development?

Answer 61

The mother

Question 62

Where is IgA derived from in the infant stage?

Answer 62

Mother's milk

Question 63

Do newborns respond well to proteins antigens?

Answer 63

Yes

Question 64

Do elderly people have weak or strong immune systems?

Answer 64

Weak with weak tolerance to self antigens