The Immune Response Ii

Front 1

What are three types of professional antigen presenting cells?

Back 1

Dendritic cells, macrophages and B cells

Front 2

What is the job of professional antigen presenting cells (APCs)?

Back 2

to activate T cells

Front 3

What is the shape of a dendritic cell?

Back 3

middle cell body with arms extending

Front 4

What is the shape of a macrophage?

Back 4

large irregular shape

Front 5

What is the shape of a B cell?

Back 5

small with antigen-specific receptors on the surface

Front 6

How do dendritic cells take in antigens?

Back 6

Macropinocytosis and phagocytosis

Front 7

How do macrophages take in antigens?

Back 7

phagocytosis

Front 8

How do B cells take in antigens?

Back 8

antigen-specific receptor (Ig)

Front 9

What types of antigens do dendritic cells present?

Back 9

peptides, viral antigens and allergens

Front 10

What types of antigens do macrophages present?

Back 10

particulate antigens, intracellular and extracellular pathogens

Front 11

What types of antigens do B cells present?

Back 11

soluble antigens, toxins and viruses

Front 12

Where are most dendritic cells found?

Back 12

in the skin or mucosal tissues as Langerhans cells

Front 13

What is the best type of APC?

Back 13

dendritic cell

Front 14

How do antigens in the epidermis find their way to T cells?

Back 14

Dendritic cells take up antigens in the skin and then move to enter a draning lymphatic vessel. Dendritic cells bearing antigen enter the draining lymph node, where they settle in the T cell areas.

Front 15

What do T cells use to find lymph nodes?

Back 15

Adhesion molecules

Front 16

What are 2 crucial adhesion molecules?

Back 16

Selectins and ICAMs

Front 17

What is the role of selectins?

Back 17

to allow lymphocytes to find lymph nodes or sites of infection

Front 18

What is the role of ICAMs?

Back 18

to allow T cells to "talk" to APCs

Front 19

What are two ways T cells can enter lymph nodes?

Back 19

via the afferent lymphatics or from the blood

Front 20

What happens when the receptor of a T cell is engaged?

Back 20

It triggers several intracellular signaling pathways ending with PKC and calcineurin activating the transcription factors NFkB and NFAT respectively

Front 21

Describe the secont signal required for T cell activation.

Back 21

Binding of TcR and CD4 to MHC class II delivers a signal to the T cell. Clonal expansion of the T cell can occur ONLY after second signal is delivered by CD80/88:CD28 interaction.

Front 22

What down-regulates the secondary signal in T cells?

Back 22

CTLA4

Front 23

What happens when the T cell only receives a "specific signal?"

Back 23

The T cell becomes anergic

Front 24

What happens when the T cell only receives a "co-stimulatory signal?"

Back 24

No effect on T cell

Front 25

Cytokines are crucial hormones for the activation and function of what type of cell?

Back 25

lymphocytes

Front 26

What is the source and effect of IL1?

Back 26

APCs / Inflammation

Front 27

What is the source and effect of IL2?

Back 27

Th1,CTL / T cell growth

Front 28

What is the source and effect of IL4 and IL5?

Back 28

TH2 / Class switching

Front 29

What is the source and effect of IFNgamma?

Back 29

Th1 / inhibitis Th2

Front 30

What is the source and effect of TNF?

Back 30

Th1 / Inflammation

Front 31

What happens in a T cell when IL2 binds to its high affinity receptor?

Back 31

Sends a growth signal to the cell, signals the cell to proliferate. Smaller amounts of IL2 can now drive T cell growth and differentiation.

Front 32

What effector molecules do CD8 T cells release?

Back 32

Perforin, Granzymes, Fas

Front 33

What is the effect of Perforin, Granzymes and Fas released by CD8T cells?

Back 33

cytotoxic (ex: against a virus infected cell)

Front 34

What effector molecules do CD4 T cells release?

Back 34

TGF-beta, IL-12, IL-4 and TNF

Front 35

What is the effect of TGF-beta release from CD4 T cells?

Back 35

causes CD4 T cells to differentiate into Treg Cells (downregulation of Th1)

Front 36

What is the effect of IL-12 release from CD4 T cells?

Back 36

causes CD4 T cells to differentiate into Th1 Cells (inflammatory)

Front 37

What is the effect of IL-4 release from CD4 T cells?

Back 37

causes CD4 T cells to differentiate into Th2 Cells (humoral)

Front 38

What is the role of Th1 cells?

Back 38

IFN-gamma secretion; host defense against intracellular microbes; inflammation

Front 39

What is the role of Th2 cells?

Back 39

IL-4, IL-5, IL-13 secretion; host defense against helminths; allergic reactions

Front 40

What happens when Th2 cells secrete TGFbeta and IL-10?

Back 40

inhibit activation and growth of Th1 cells

Front 41

What happens when Th1 cells secrete IFNgamma?

Back 41

Inhibit proliferation of Th2 cells

Front 42

Do effector CD8 T cells need further costimulation to remain active once activated by APCs?

Back 42

No

Front 43

How do CTLs kill their target cell?

Back 43

They secrete perforins and granzymes into the target cell and cause death by apoptosis - uninfected neighboring cells are spared.

Front 44

What cells are responsible for cellular immunity?

Back 44

Th1 cells

Front 45

What cells are responsible for humoral immunity?

Back 45

Th2 cells

Front 46

What is needed for macrophages to become highly microbiocidal?

Back 46

T cell must bind to and activate the macrophage (CD40-CD40L interaction AND Th1 cytokines)

Front 47

What can be formed around macrophages if pathogens cannot be totally eliminated?

Back 47

granulomas (induced by Th1 cells)

Front 48

What is required for B cell class switching?

Back 48

CD40-CD40L interaction

Front 49

Th2 cells provide help to B cells and coordinate what type of immunity?

Back 49

anti-parasite

Front 50

Both T and B effector and memory cells are produced in which immune response?

Back 50

primary