EXAM 3 NK Cells and gamma delta T Cells

Question 1

NK cells are derived from a common ___ precursor

Answer 1

lymphoid

Question 2

NK cells provide the interface between what?

Answer 2

adaptive and innate immunity

Question 3

NK cells are developmentally similar to ___ cells

Answer 3

T cells

Question 4

NK cells have diverse ___ expression and interaction

Answer 4

receptor

Question 5

NK cells are regulated by interactions with ___

Answer 5

MHC I molecules

Question 6

NK cells recognize targets by their lack of ___

Answer 6

MHC I

Question 7

can NK cells form memory cells?

Answer 7

yes

Question 8

what determines NK cell killing?

Answer 8

positive and negative signal balance

Question 9

describe the 3 cell states that regulate NK cell targeting

Answer 9

1. protection - healthy cells express both stimulating and inhibitory signals
2. missing-self - unhealthy cells reduce MHC I expression
3. induced-self - unhealthy cells increase stress ligand expression

Question 10

do all NK cells detect MHC I receptors or stress ligands?

Answer 10

no

Question 11

in NK cell targeting, ___ signals must overcome ___ signals

Answer 11

• stimulating
• inhibitory

Question 12

NK cells must be educated to detect a lack of ___

Answer 12

receptor expression

Question 13

what are the important roles cytokines play in NK cell targeting?

Answer 13

• stimulating signal
• receptor expression
• IFNs, IL-12

Question 14

do NK cells express diverse combinations of receptors or do they only have a few?

Answer 14

diverse combinations

Question 15

what are the activating and inhibitory receptors on NK cells?

Answer 15

• activating - NKG2D and CD16 (Fc receptor)
• inhibitory - NKG2A and KIR family

Question 16

describe the CD16 NK cell receptor family

Answer 16

• activating receptor
• low affinity IgG Fc receptor

Question 17

describe the NKG family of NK cell receptors

Answer 17

• NKG2A - inhibitory receptor that preferentially binds MHC I
• NKG2D - activating receptor that binds MIC proteins (stress ligands)

Question 18

describe the KIR family of NK cell receptors

Answer 18

• killer-cell immunoglobulin-like receptor family
• binds MHC I
• inhibits NK cell activation (mostly, some exceptions)
• detects healthy self tissue

Question 19

inhibitory NK cell receptors recognize conventional ___

Answer 19

MHC I

Question 20

activating NK cell receptors recognize ___

Answer 20

stress ligands

MHC I related, non-classical molecules

Question 21

cells usually express ___ or a ___ receptor, not both

Answer 21

NKG2A or KIR

Question 22

detection of MHC I ___ NK killing, while lack of MHC I detection ___ NK killing

Answer 22

• prevents
• leads to

Question 23

what are the NK cell activation responses?

Answer 23

1. target cell interaction
   
   1. downregulated MHC I
   2. stress ligands
   3. CD16
2. leukocyte interaction
   
   1. antigen presenting cells
   2. Th cells
   3. NKT cells
3. cytokines
   
   1. IFNs, IL-12
   2. proliferation, receptor expression, cytokine and granule production

Question 24

what are the NK cell effector functions?

Answer 24

cytokine release and cytotoxicity

Question 25

how do NK cells detect and kill cells with altered MHC I expression?

Answer 25

Question 26

what is the innate mechanism of NK cell activation?

Answer 26

* multiple (2) signals * MHC surveillance * stress ligands * signals from two or more activating receptors are required to activate NK cells

Question 27

what is the adaptive mechanism of NK cell activation?

Answer 27

* single signal * Ig targeting * In the presence of IgG, the Fc receptor can activate NK cells without help from another receptor

Question 28

describe NK cell cytotoxicity

Answer 28

* degranulation * perforin and granzyme * death-receptors * FasL and TRAIL * interferons and nitric oxide

Question 29

\_\_\_ T cells monitor tissue health

Answer 29

gamma delta their major role is to remove diseased and malignant cells

Question 30

gamma delta T cells are prominant where?

Answer 30

in tissues and mucosal surfaces * sit in epithelial layers * intraepithelial lymphocytes (IEL)

Question 31

which unique antigens do gamma delta T cells bind?

Answer 31

* phosphoantigens * phopsholipids * lipids

Question 32

describe how gamma delta cells have both CD8-like and CD4-like activity

Answer 32

* direct killing * cytokine and chemokine release * NK, macrophage, and DC activation

Question 33

\_\_\_ cells can migrate to lymph nodes and function as antigen-presenting cells

Answer 33

gamma delta T cells

Question 34

gamma delta T cells express ___ receptors

Answer 34

stress-ligand * similar to NK cells * detects the presence and absence of MHC I

Question 35

gamma delta T cells promote \_\_\_

Answer 35

tissue repair and homeostasis