CMI and Humoral Immunity

Question 1

Dendritic cells express costimulatory molecules:

Answer 1

• CD40L:CD40

- CD28:B7.1 or 7.2 (CD80 or 86)

Question 2

p-SMAC:

Answer 2

Peripheral Supramolecular Activation Complex.

- Stabilizes T-cell:Dendritic cell interaction.

Question 3

Binding of MHC to TCR leads to:

Answer 3

ITAM phosphorylation by Lck.

Question 4

TCR signaling leads to the formation of 3 transcription factors (IL-2 promoter):

Answer 4

1. NFAT
2. NFkB
3. AP-1

Question 5

Peripheral tolerance:

Answer 5

Self reactive T cell escaped thymic selection sees self antigen but no costimulation = anergy/apoptosis.

Question 6

Th0 gives rise to (5):

Answer 6

1. Th1
2. Th2
3. Th17
4. Tfh
5. Tregs

Question 7

Th0 –> Th1

Answer 7

IL-12

Question 8

Th0–> Th2

Answer 8

IL-4

Question 9

Th0 –> Th17

Answer 9

IL-23

Question 10

Th0 –> Treg

Answer 10

TGF-beta

Question 11

Th0 –> Tfh

Answer 11

IL-21

Question 12

Th1 secrete:

Answer 12

• IL-12

- IFN-gamma

Question 13

Th17 secrete:

Answer 13

• IL-17

- IL-6

Question 14

Th2 secrete:

Answer 14

• IL-4

- IL-5

Question 15

Tfh secrete:

Answer 15

• IL-21
• IL-10
• TGF-beta

Question 16

Treg secrete:

Answer 16

• TGF-beta

- IL-10

Question 17

CTL killing:

Answer 17

• Rapid.
• Requires cell:cell contact.
• Uni-directional.
• CTL can kill multiple targets.
• Bystander cells unaffected.

Question 18

3 steps to CTL killing:

Answer 18

1. CTL target binding.
   
   • Initial contact independent of antigen (Mg dependent).
   • Granule reorientation
2. Programming the target for lysis (Ca2+ dependent).
3. Target cell death.

Question 19

Proteins in granules of CTL cells (3):

Answer 19

1. Perforin.
2. Granzymes.
3. Granulysin.

Question 20

Perforin:

Answer 20

Aids in delivering contents of granules to cytoplasm of target cell.

Question 21

Granzymes:

Answer 21

Serine proteases which activate apoptosis once in the cytoplasm of target cell.

Question 22

Granulysin:

Answer 22

Has antimicrobial actions and can induce apoptosis.

Question 23

IL-7

Answer 23

Required for T cell survival.

Question 24

3 types of memory cells:

Answer 24

1. Central.
2. Effector.
3. Resident.

Question 25

Memory cells that do not circulate:

Answer 25

Resident Memory Cells.

Question 26

Memory cells remain in lymphoid tissue:

Answer 26

Central memory cells.

Question 27

Memory cells that migrate to tissues:

Answer 27

Effector memory cells.

Question 28

nTregs:

Answer 28

Natural Tregs

- Derived in thymus, suppress immune function nonspecifically.

Question 29

iTregs:

Answer 29

Induced Tregs

- Antigen specific inhibition.

Question 30

MDSC:

Answer 30

Myeloid Derived Suppressor Cells

• Granulocyte or monocyte like.
• Inhibit T cell response via arginase production.
• Release TGF-beta.