T cell mediated immunity II

Question 1

After an infection is resolved, __% of CTLs undergo apoptosis.

Answer 1

After an infection is resolved, ~90%% of CTLs undergo apoptosis.

Question 2

How Th1 cells activate macrophages

Answer 2

IFN-γ production

CD40L

Both promote classical activation

Question 3

IL‐5

Answer 3

A potent eosinophil growth factor and activator

Question 4

ILCs vs T cells

Answer 4

ILCs have no antigen receptor, but have analogous effector functions to T_H1, 2, and 17.

NK cells are also ILCs, and are the functional equivalents of CTLs.

Question 5

T cell memory can last for up to ____ years.

Answer 5

T cell memory can last for up to 75 years.

Question 6

Th1, Th2, Th17, and Tfh

Answer 6

Question 7

Perforin molecules that diffuse away are inhibited by ___.

Answer 7

Perforin molecules that diffuse away are inhibited by plasma lipids.

Question 8

Pathogen types and associated T_H subsets

Answer 8

Question 9

Classical vs Alternative macrophage activation

Answer 9

Question 10

_____ are required for ILC development from a common precursor

Answer 10

IL‐15 or IL‐7 are required for ILC development from a common precursor

Question 11

CTL granule contents

Answer 11

Question 12

At peak after EBV, CMV, HIV infection, ____ % of all T cells in the blood may be specific for just one single viral peptide‐ MHC antigen

Answer 12

At peak after EBV, CMV, HIV infection, 25‐ 50 % of all T cells in the blood may be specific for just one single viral peptide‐ MHC antigen

Question 13

CTL-Target Cell Interaction

Answer 13

Question 14

Bystander cells (e.g. antigen presenting cells) may be protected from CTL-mediated death by expressing _____

Answer 14

Bystander cells (e.g. antigen presenting cells) may be protected from CTL-mediated death by expressing specific and irreversible granzyme inhibitors (serpins).

Question 15

Helper T cell Differentiation

Answer 15

Question 16

T_H2 functions

Answer 16

Question 17

Development of ILCs

Answer 17

Question 18

Clonal expansion of T cells

Answer 18

Question 19

The major benefit of CD4 help to CD8 cells is enhanced _____.

Answer 19

The major benefit of CD4 help to CD8 cells is enhanced generation of memory CD8 T cells.

Question 20

All T_H subsets

Answer 20

1, 2, 3, 9, 17, 22, follicular helper, regulatory

Question 21

IL‐22

Answer 21

Enhances epithelial barrier function by promoting epithelial cell growth (to repair breaches) and reinforcing tight junctions.

Also increases defensin production.

Question 22

JAK STAT Signaling

Answer 22

Question 23

Classical Macrophage Activation

Answer 23

Question 24

“licensing” of the DC

Answer 24

T cell activation by a DC recpirocally activates the costimulatory activity of the DC, as it has been “liscensed” as a dangerous antigen-carrying DC. This makes subsequent CD4 or CD8 T cell activation easier.

Question 25

IL‐4 and IL‐13

Answer 25

* Mediate class switching to IgE * Activate eosinophils, mast cells, basophils * enhance gut peristalsis to expel worms * induce alternative macrophage activation (IL-10, tissue fibrosis) * Sensitizes eosinophils and mast cells

Question 26

\_\_\_\_\_ may lead to granulomatous inflammation

Answer 26

**Chronic T_H1 responses** may lead to granulomatous inflammation Particularly when the microbe cannot be killed by the phagocyte or ecsapes into its cytoplasm (eg, *Mycobacterium tuberculosis*)

Question 27

Evasion of CTL Surveillence

Answer 27

Question 28

Immunologically Relevant STATs

Answer 28

Question 29

CD4/CD8 interaction

Answer 29

Question 30

Differentiation of naive CD8⁺ T cells into CTLs

Answer 30

Question 31

Shared properties of T cells and ILCs

Answer 31

Question 32

CTLs secrete the major cytokines ____ and \_\_\_\_.

Answer 32

CTLs secrete the major cytokines **TNF-****α**and**IFN-γ**.

Question 33

The role of ILCs vs that of T cells

Answer 33

* ILCs are innate early responders, already present and ready to respond before prior antigen exposure * ILCs do not have clonally distributed antigen receptors and thus are not highly antigen specific * ILCs do not contribute to memory responses

Question 34

Life of a CD8⁺ T Cell

Answer 34

Question 35

T_H17 functions

Answer 35

Question 36

Eosinophils are circulating granulocytes that are not ____ like neutrophils, but instead \_\_\_\_.

Answer 36

Eosinophils are circulating granulocytes that are not **phagocytic** like neutrophils, but instead **release proteolytic granule contents**.