Lecture 2: Intro To Innate Immunity Flashcards Preview

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Flashcards in Lecture 2: Intro To Innate Immunity Deck (97):
1

The mechanical barriers involved in innate immunity include epithelial cells joined by _______ ________, along with the longitudinal flow of air or fluid, movement of mucus by ___________, as well as tears and nasal cilia.

Tight junctions; cilia

2

What chemical barrier defenses exist in the skin?

Fatty acids
Beta-defensins
Lamellar bodies
Cathelicidin

3

What chemical barriers exist in the gut?

Low pH (pepsin)
Alpha-defensins (cryptidins)
RegIII (lecticidin)
Cathelicidin

4

What chemical defenses exist in the lungs?

Alpha-defensins
Cathelicidin
Pulmonary surfactant

5

What chemical defenses exist in the eyes/nose/oral cavity?

Enzymes in tears and saliva = lysozyme

Histatins, beta-defensins

6

What is the microbiological barrier associated with the first line of defense against pathogens?

Normal microbiota

7

___________ is a peptide that comes from neutrophils, mast cells, epithelia (skin, lung, GI, GU, oral), sweat, and seminal fluid that has antimicrobial and chemotactic action

Cathelicidin

8

____________ are peptides that come from neutrophils and have antimicrobial action

Alpha-defensins

9

__________ are peptides that come from neutrophils and epithelia (skin, oral, mammary, lung, urinary, eccrine, occular), and participate in antimicrobial, chemotactic and histamine release

Beta-defensins

10

Fatty acids and lactic acid are chemical barriers to infection that are primarily found in what bodily fluids?

Sweat
Sebum

11

Destructive enzymes like lysozyme and phospholipase are primarily found in what bodily secretions?

Tears
Saliva
Nasal secretions

12

Where does an acidic pH play a role as a chemical barrier to infection?

Stomach
Skin
Vagina

13

The lungs secrete surfactant proteins ___ and ___ as chemical barriers to infection

A
D

14

Defensins are found in what 3 major areas?

Lungs
GI tract
Skin

15

What are the 3 types of granulocytes?

Eosinophils
Basophils
Mast cells (tissue residents)

16

The main role of granulocytes in general is in _______ disease

Atopic

17

Natural killer cells express which 2 CD molecules?

CD16
CD56

18

NK cells provide innate immunity against __________ infections like viruses and cancer

Intracellular

19

What cell type is also known as polymorphonuclear cells and makes up 54-62% of white blood cells?

Neutrophils

20

Neutrophils are released from _______ ________ into the blood and migrate 7-10 hours then home to the tissue where they have a ______ day lifespan

Bone marrow
3

21

In response to an infection, neutrophils will be released from bone marrow in greater numbers in a process called ___________ ___________

Neutrophil leukocytosis

22

True or false: Neutrophils are the FIRST to the site of the infection, and are HIGHLY phagocytic

True

23

Neutrophils are a large component of pus/abscesses, meaning they are ___________

They express ______ and ______ CD markers

Pyogenic
CD15
CD16b

24

Neutrophils serve one purpose: professional killers. They are summoned from the bloodstream by what 3 cytokines?

IL-1
TNF-a
IL-8

25

Once neutrophils have been recruited by IL-1, TNF-a, and IL-8, endothelial cells near the site of infection begin expressing __________ proteins (adhesion molecules) that help capture the neutrophils attention

Selectin

26

_________ is the cell surface marker of macrophages, which recognizes and binds ________

CD14 (TLR4)
LPS

27

__________ respond to sites of inflammation in 1-2 days, but survive longer than neutrophils. Levels may be inreased in chronic inflammation, various immune-mediated diseases, stress response, and necrosis

Monocytes/macrophages

28

What are the 3 primary functions of monocytes/macrophages?

Garbage collecters (resting)
APCs (activated/primed)
Vicious killers (hyperactivated)

29

True or false: M1 macrophages have anti-inflammatory effects and participate in wound repair and fibrosis

False, this is a description of M2 (alternative) macrophages

30

M2 macrophages are induced by _____ and ______

IL-4
IL-13

31

Macrophage activity can be enhanced by ___ cytokines

T Helper cell

32

Activated macrophages have:

Increased phagocytic activity.

Increased ability to activate _____ cells.

Higher levels of _______on the cell surface

T helper

Class II MHC

33

What type of cell constitutively expresses high levels of class II HLA/MHC and CD80?

Dendritic cells

34

What makes dendritic cells an important bridge between innate and adaptive immunity?

They are professional APCs

35

What makes dendritic cells better APCs than macrophages and B cells?

Their constitutive expression of class II MHC and CD80

36

__________ are molecules/structures that are shared by various classes of microbes but are not present on self

PAMPs (pathogen associated molecular patterns)

37

__________ are molecules released by stressed cells undergoing necrosis that act as endogenous danger signals to promote and exacerbate the inflammatory response

DAMPs (damage associated molecular patterns)

38

Binding of PAMP ligands to _______ induces intracellular signaling in the phagocytes leading to their ___________

PRRs
Activation

39

The largest family of PRRs are the __________, which have receptors with specificities for different microbial products, respond to both exogenous and endogenous antigens, and are present on macrophages, dendritic cells, and neutrophils

TLRs

40

Is the following TLR intracellular or extracellular and what type of PAMP does it recognize:

TLR-8

Intracellular

ssRNA

41

Is the following TLR intracellular or extracellular and what type of PAMP does it recognize:

TLR-2

Extracellular

Peptidoglycan

42

Is the following TLR intracellular or extracellular and what type of PAMP does it recognize:

TLR-1:TLR-2

Extracellular

Bacterial Lipopeptides

43

Is the following TLR intracellular or extracellular and what type of PAMP does it recognize:

TLR-3

Intracellular

dsRNA

44

Is the following TLR intracellular or extracellular and what type of PAMP does it recognize:

TLR-2:TLR-6

Extracellular

Bacterial Lipopeptides

45

Is the following TLR intracellular or extracellular and what type of PAMP does it recognize:

TLR-4

Extracellular

LPS

46

Is the following TLR intracellular or extracellular and what type of PAMP does it recognize:

TLR-5

Extracellular

Bacterial flagellin

47

Is the following TLR intracellular or extracellular and what type of PAMP does it recognize:

TLR-7

Intracellular

ssRNA

48

Is the following TLR intracellular or extracellular and what type of PAMP does it recognize:

TLR-9

Intracellular

TLR-9

49

Binding of ligand to a TLR results in phagocytosis, production and secretion of _____________, increased ________, and increased cytoskeletal changes

Cytokines
ROS

50

______________ is another way to recognize and respond to pathogens. Phagocytes have membrane receptors for IgG and C3b which facilitate the enhancement of phagocytosis up to 4000-fold

Opsonization

51

What are the 2 primary intracellular killing mechanisms?

Oxygen-independent killing
Oxygen-dependent killing

52

What is the oxygen-independent killing mechanism?

Lysozyme, defensins, lactoferrin, and hydrolytic enzymes contained in the lysosome

53

What 2 enzymes does the oxygen-dependent killing mechanism depend on?

NADPH oxidase

Myeloperoxidase

54

Chediak-Higashi syndrome results from microtubule defect affecting phagosome-lysosome fusion.

Genetically, it is _____________ ____________.

It is characterized by partial oculocutaneous ____________, recurrent _____________ infections, and the presence of giant _________ in leukocytes.

Autosomal recessive

Albinism
Pyogenic
Granules

55

Chronic granulomatous disease results from an inherited deficiency in __________ _____________, leading to decreased production of reactive oxygen species.

Clinically, it results in chronic, recurrent infections with ____________-______________ microorganisms like Staphylococcus, Klebsiella, Serratia, and Aspergillus.

Chronic inflammatory symptoms like gingivitis, enlarged lymph nodes, and tumor-like ___________ masses.

NADPH oxidase

Catalase-positive

Granuloma

56

What neonatal finding may be indicative of chronic granulomatous disease?

Omphalatis (failed or delayed separation of the umbilical cord)

57

If chronic granulomatous disease results from a deficiency in NADPH oxidase, why is immunity only affected in terms of catalase-positive organisms?

The patient still has adequate myeloperoxidase, which is able to continue killing most bacteria.

However, catalase-positive organisms can neutralize H2O2 species that your body is trying to utilize to kill them, and thus survive in the phagosome.

58

What are the 3 principle cell sources of tumor necrosis factor (TNF)?

Macrophages
T cells
Mast cells

59

What effect does TNF have on the following:

Endothelial cells
Neutrophils
Hypothalamus

Endothelial cells: activation (inflammation, coagulation)

Neutrophils: Activation

Hypothalamus: fever

60

What effect does TNF have on the following:

Liver
Muscle
Many cell types

Liver: synthesis of APPs

Muscle: fat catabolism (cachexia)

Many cell types: apoptosis

61

What 5 cell types secrete IL-1?

Macrophages
Dendritic cells
Endothelial cells
Epithelial cells
Mast cells

62

What effect does IL-1 have on the following:

Endothelial cells
Hypothalamus
Liver
T cells

Endothelial cells: activation (inflammation, coagulation)

Hypothalamus: fever

Liver: synthesis of APPs

T cells: Th17 differentiation

63

What 6 cell types secrete chemokines?

Macrophages
Dendritic cells
Endothelial cells
T lymphocytes
Fibroblasts
Platelets

64

What effect do chemokines have on leukocytes?

Increased integrin affinity, chemotaxis, activation

65

What 2 cell types secrete IL-12?

Dendritic cells
Macrophages

66

What effect does IL-12 have on the following cell types:

NK cells and T cells

T cells

NK cells and T cells: IFN-y production, increased cytotoxic activity

T cells: Th1 differentiation

67

What 2 cell types secrete IFN-y?

NK cells
T cells

68

What effect does IFN-y have on its cellular targets?

Activation of macrophages

Stimulation of some antibody responses

69

What are the 2 principle cell sources for IFN-alpha?

Dendritic cells
Macrophages

70

What is the principle cell source for IFN-beta?

Fibroblasts

71

What effects do IFN-alpha and IFN-beta have on the following:

All cells

NK cells

All cells: antiviral state = increased class I MHC expression

NK cells: activation

72

What are the 3 cell sources of IL-10?

Macrophages
Dendritic cells
T cells

73

What effect does IL-10 have on macrophages and dendritic cells?

Inhibition of cytokine and chemokine production, reduced expression of costimulators and class II MHC molecules

74

What are the 3 principle cell sources of IL-6?

Macrophages
Endothelial cells
T cells

75

What effect does IL-6 have on the following:

Liver

B cells

Liver: synthesis of APPs

B cells: proliferation of antibody-producing cells

76

What is the principle cell source of IL-15?

Macrophages

77

What effect does IL-15 have on the following:

NK cells
T cells

NK cells: proliferation

T cells: proliferation

78

What is the principle cell source of IL-18?

Macrophages

79

What effect does IL-18 have on NK cells and T cells?

IFN-y synthesis

80

TGF beta is secreted by many cell types. What is its generalized effect and what effect does it have on T cells?

Inhibition of inflammation

T cells: differentiation of Th17, regulatory T cells

81

What cytokines are responsible for directly inhibiting viral replication?

Type I interferons (alpha and beta)

82

How do type I interferons go about inhibiting viral replication?

They degrade viral mRNA which nonspecifically shuts down cellular protein synthesis

83

What other role do type I interferons play in the protection of the cells surrounding an infected cell?

IFNs produced by virally infected cell protect neighboring cells via IFN receptors

84

Natural Killer cells express _______ and ______, and provide innate immunity against intracellular infections (especially viral) and cancer

CD16; CD56

85

NK cells have effector mechanisms similar to cytotoxic T cells in that they perform cell killing and secretion of cytokines.

They also secrete __________ and _________ which induce apoptosis in the target cell

Perforin
Granzymes

86

What 3 cytokines serve to activate NK cells?

IL-12 (from macrophages)
IL-15
Type I IFNs

87

What cytokine do NK cells secrete that is responsible for activating macrophages?

IFN-y

88

NK cells destroy bacteria, parasites, fungi, tumor cells, and virus-infected cells by forcing them into apoptosis.

This is done by first secreting _________ proteins that deliver "suicide" enzyme _____________ into the target cell.

_____ ligand expressed on their cell surface binds death receptor on target cell to induce apoptosis

Perforin; granzyme B

Fas

89

How do macrophages and NK cells work together to fight infection?

Macrophages that have phagocytosed microbes find NK cells and secrete IL-12 to activate them

Those NK cells then secrete IFN-y to further activate macrophages

90

Why don't NK cells target healthy cells?

They have an inhibitory receptor that binds to MHC class I (an indicator of healthy cells)

Viruses inhibit class I MHC expression, so the NK cell inhibitory receptor is not engaged and thus the infected cell will be killed.

91

What would be the general result in a phagocyte deficiency?

Increased susceptibility to extracellular bacteria and fungi

92

What would be the general result of an NK cell deficiency?

Increased susceptibility to viral infections, especially Herpes Simplex

93

What type of deficiency would lead to widespread pyogenic bacterial infections?

Leukocyte adhesion deficiency

94

What disease leads to intracellular and extracellular infections as well as large collections of cells that cannot be cleared?

Chronic Granulomatous Disease

95

What deficiency results in defective respiratory burst and chronic infections?

G6PD deficiency

96

What deficiency leads to defective intracellular killing and chronic infections?

Myeloperoxidase deficiency

97

What syndrome results in intracellular and extracellular infections as well as granulomas, other than CGD?

Chediak-Higashi syndrome