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Flashcards in Basic immunology concepts Deck (86):
1

C3bBb3b

Alternative C5 convertase

2

Alternative C3 convertase

C3bBb

2

Stimulates bone marrow

IL-3

3

Which two cell types posses granulysin, granzyme and perforin? What are their respective functions?

NK and CD8+ cells

Perforin - forms holes

Granzyme - protease, induces apoptosis

Granulysin - antimicrobial, induces apoptosis

3

Inhibited by IL-4 and IL-10

TH1

3

C4b2b3b

Classic C5 convertase

4

What is the function of TH2 cells?

Induce class switching to IgE and recruit eosinophils

5

What is the function of Tregs?

Maintain immune tolerance by suppressing CD4+ and CD8+ effector function

5

Stimulates growth of B cells vs. stimulates differentiation of B cells

Growth = IL-4

Differentiation = IL-5

5

Signal transduction for T cells

CD3

5

What does EBV bind to infect its cell?

EBV binds CD21+ on B cells

 

(but remember the big cells = CD8+ cells)

6

Surface marker of neutrophils

CD15+

 

(also Reed-Sternberg cells)

6

What are the two complement inhibitors and what is their main function?

C1 esterase inhibitor and DAF

Prevent complement activation of self cells

7

Binds LPS

CD14+ of macrophages and monocytes

8

Stimulates T cells

IL-2

9

Where does positive seletion occur and what is its purpose?

Cortex

T cells capable of binding self-antigen are selected to survive

9

How can Tregs be identified?

CD3+, CD4+, CD25+, FOXP3 transcription factor

10

Alternative C5 convertase

C3bBb3b

11

Fever

IL-1, IL-6

13

TH2 cells develop under influence of which cytokine?

IL-4

14

C4b2b

Classical C3 convertase

14

Secreted by macrophages to activate NK cells and induce differentiation into TH1 cells

IL-12

14

What is the function of IF alpha and beta?

Released by virally-infected cells to prime neraby cells for infection

16

Which occurs first: + or - selection?

+

16

Binds Cd3

CD21+ of B cells

17

Which cytokines are released by TH2 cells?

!L-4. IL-5, !L-6, IL-10, IL-13

18

C3bBb

Alternative C3 convertase

19

CD4+ exposed to IL-12

TH1

19

Classical C3 convertase

C4b2b

20

What occurs when a virus enters a cell that has been primed by IF alpha +/- beta from a nearby cell?

The viral RNA polymerase activates RNase, which cleaves viral and host mRNA, and protein kinase, which prevents viral and host protein synthesis, effectively causing apoptosis of the cell to prevent viral spread

21

Activates osteoclasts

IL-1

21

All surface markers on NK cells

CD16, CD56

22

All surface markers on macrophages

CD14, CD40, B7, MHC class II, Fc and C3b receptor

23

CD15+

Neutrophils and Reed-Sternberg cells

24

Increases MHC expression and antigen presentation by all cells

IFgamma from TH1 cells

25

Tregs develop under influence of which cytokines?

TGFß

26

Mediates septic shock

TNFalpha

28

Where does negative selection occur and what is it's purpose?

Medulla (M = N)

T cells with high affinity for self-antigen are selected to undergo apoptosis

28

FOXP3 transcription factor

Tregs

29

Promotes growth and differentiation of eosinophils

IL-5

 

(although IL-4 stimulates class switching to IgE)

30

What does LPS bind to stimulate immunity?

CD14 on macrophages/monocytes

 

(Remember: LPS is not a protein, so it is a thymus-indepedent antigen = T cells not involved)

31

CD14+

Macrophages and monocytes (binds LPS)

32

All surface markers on a killer T cell

CD8, CD3, CD28

34

Surface marker of macrophages and monocytes

CD14+

36

Describe the interaction between TH1 cells and macrophages

Macrophages release IL-12 which stimulates differentiation into TH1 cells, which in turn secrete IFgamma, which activates macrophages

37

Two roles of C3b

Opsonization

Clearing immune complexes

38

TH2 cell secretes IL-5. What happens to B cell?

Class switching to IgA

38

Activates production of acute phase reactants

IL-6

39

What is the signal for ADCC?

CD16 binds to Fc portion of IgG on cell to be killed; NK cell releases granzyme and perforin

40

What is the function of TH1 cells?

Activate macrophages and CD8+ cells

42

Two primary opsonins

IgG and C3b

44

TH17 cells develop under influence of which cytokines?

!L-6 and TGFß

45

CD19+/CD20+/CD21+

Mature B cell (see in CLL)

46

CD3+ CD4+ CD25+

Tregs

47

Which cytokine functions similarly to GM-CSF?

IL-3 (Activates bone marrow)

48

Cytokines secreted by macrophaes

IL-1, IL-6, IL-12, TNFalpha

50

Secretes IFgamma

TH1

51

Tdt+

Pre-B and pre-T cells (see in ALL)

53

TH1 develops under influence of which cytokine?

IL-12

55

CD4+ exposed to !L-6 and TGFß

TH17

56

Steps in the lectin complement pathway

MBL binds mannose on microbial surfaces --> activates a C1-like complex --> cleaves C4 into C4a and C4b --> C4b joins C2b from the classical pathway --> classical C3 convertase C4b2b formed --> cleaves C3 into C3a and C3b --> C3b joins to form classical C5 convertase C4b2b3b --> cleaves C5 into C5a which is a PMN recruiter and C5b --> C5b joins C6-9 to form MAC --> cytotoxicity and lysis

57

CD10+

Pre-B cell (see in ALL)

58

What happens after T cells undergo negative selection in the thymus?

They move to the bone marrow where CD4+ cells differentiate

59

What are the three signals needed for B cell activation and subsequent class switching?

1. B cell receptor-mediated endocytosis of antigen with presentation on MHC class II recognized by TH cell

 

2. CD40 on B cell binds CD40L on TH cell

 

3. TH cell secretes cytokines that determine class switching

60

What is the function of each cytokine secreted by TH2 cells?

!L-4 = IgE and IgG class switching

IL-5 = IgA class switching

IL-6 = stimulates acute phase reactant production

IL-10 = inhibit TH1 differentiation

IL-13 = allergic and parasitic responses

61

Activates NK cells

IL-12

62

Causes vascular leak

TNFalpha

64

What two signals are needed for T cell activation?

1. Antigen presentation by an APC (B cell, MØ, dendritic cell) on MHC class I or class II

 

2. B7 on APC binds CD28+ on T cell = co-stimulatory signal

65

Which cytokines are released by TH1 cells?

IFgamma

67

Which cytokines inhibit differentiation into TH1 cells?

IL-4, IL-10 from TH2 cells

68

Surface markers of mature B cell

CD19+/CD20+/CD21+

70

TH2 cell secretes IL-4. What happens to B cell?

Class switching to IgE and IgG

72

Classic C5 convertase

C4b2b3b

74

Which cytokines are produced by Tregs?

IL-10 and TGFß (anti-inflammatory)

75

Steps in the classical complement pathway

C1 binds IgG or IgM Fc region --> C1 complex cleaves C2 into C2a and C2b --> C2b joins C4b from lectin pathway --> classical C3 convertase C4b2b formed --> cleaves C3 into C3a and C3b --> C3b joins to form classical C5 convertase C4b2b3b --> cleaves C5 into C5a and C5b --> C5b joins C6-9 to form MAC --> cytotoxicity, lysis

76

Steps in alternative complement pathway

Microbial surface or spontaneous activation causes C3 to cleave into C3a and C3b --> C3b joins with Bb (B is cleaved via D) --> alternative C3 converstase C3bBb is formed --> cleaves more C3 --> C3b joins C3 convertase to form C5 convertase C3bBb3b --> cleaves 5 into 5a which recruits PMNS and 5b --> 5b joins 6-9 --> MAC formed --> lysis, cytotoxicity

77

All cell surface markers on helper T cell

CD4, CD3, CD28, CD40L

78

All surface markers on B cells

CD19, CD20, CD21, CD40, Ig, MHC II, B7

79

Which two cytokines are secreted by all T cells?

IL-2 and IL-3

80

Inhibited by IFgamma

TH2

81

Activates adhesion molecule expression on endothelium

IL-1

82

CD4+ exposed to TGFß only

Tregs

83

CD4+ exposed to IL-4

TH2

84

Secretes IL-4, IL-5, IL-6, IL-10, IL-13

TH2

85

Secretes IL-10 and TGFß

Tregs

86

Surface marker when T cell enters thymus

CD4+CD8+