NK cells and Friends

Question 1

Which lymphocyte cell destroys diseased self cells, is innate as well as adaptive, is similar to T cells, interacts with MHC I and recognizes its absents, balances activation and inhibitory signals and may form memory cells?

Answer 1

Natural Killer Cells

Question 2

What are two major activating NK-cell receptors?

Answer 2

1-NKG2D: lectin-like, MIC-A/B and ULBP1-6 ligands

2-CD16: IgG like, IgG ligand

Question 3

What is the lectin-like inhibitory NK-cell receptor that binds HLA-E with bound peptides derived from HLA-A,B,C?

Answer 3

NKG2A

Question 4

What are 4 Ig-like inhibitory NK-cell receptors?

Answer 4

1-KIR2DL1: C2 epitope of HLA-C
2-KIR2DL2/3: C1 epitope of HLA-C
3-KIR3DL1: Bw4 epitope of HLA-A,B
4-KIR3DL2: HLA-A

Question 5

Which three MHC class I subtypes are bound by T cell and NK cell receptors?

Answer 5

HLA-A,B,C

Question 6

Which 2 MHC class I subtypes are bound by NK cell receptors only?

Answer 6

HLA-E,G

Question 7

Which MHC class I subtype is bound by intracellular chaperones?

Answer 7

HLA-F

Question 8

NKG2A NK cell receptor predominantly binds what?

Answer 8

HLA-E

Question 9

KIR receptors predominantly bind what?

Answer 9

HLA-A,B,C

Question 10

What are the three major NK cell receptor families?

Answer 10

1-CD16 (Low affinity IgG Fc receptor
2-NKG family
a.NKG2A (inhibitory receptor binding HLA-E)
b.NKG2D (Activating receptor binds MIC proteins)
3-Killer-cell immunoglobulin like receptor family (KIR) Bind HLA-A,B,C and inhibit NK cell activation

Question 11

Which activating mechanism of NK cells requires two or more signals, MHC surveillance and responds to Stress ligands?

Answer 11

Innate

Question 12

Which activating mechanism of NK cells requires only one signal and targets IgG through Fc receptor?

Answer 12

Adaptive

Question 13

NK cell interaction of HLA-E with NKG2A does what?

Answer 13

Prevents NK cell from attacking a healthy cell

Question 14

A cell that lacks HLA-E and expresses MIC engages NKG2D in combination with 2B4 and does what?

Answer 14

Activates NK cell to kill the infected cell

Question 15

What are the three cell states that regulate NK cell targeting?

Answer 15

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 16

What process occurs in the bone marrow, primes NK cells for activation with activating and inhibiting balance?

Answer 16

Education

Question 17

Interaction of KIR2DL3 and C1 during NK cell development educates the cell to do what?

Answer 17

Be sensitive to loss of C1 expression. Lack of C1 expression leads to NK killing of cell

Question 18

An Immature NK cell in bone marrow expresses inhibitory KIR that recognizes self HLA-C to do what?

Answer 18

Educate the NK cell to recognize the inhibitory receptor to not kill when present

Question 19

What are 3 NK cell activation responses?

Answer 19

1-Target cell interaction
2-Leukocyte interaction (antigen presenting cells, Th cells, NKT cells)
3-Cytokines

Question 20

What are 2 NK cell effector functions?

Answer 20

1-Cytokine release

2-Cytotoxicity

Question 21

What are the three NK cell cytotoxic effector responses?

Answer 21

1-Degranulation
2-Death-receptors (induced Apoptosis)
3-Interferon and Nitric oxide

Question 22

What do γ:δ cells do?

Answer 22

Monitor tissue health

Question 23

What three types of antigens do γ:δ cells bind?

Answer 23

1-Phosphoantigens
2-Phospholipids
3-Lipids

Question 24

What do CD1 molecules bind?

Answer 24

Lipid antigens

Question 25

The exquisite specificity of the interaction with hydrophilic head groups of self and non-self lipids are detected by presentation to γ:δT cells by what?

Answer 25

CD1d

Question 26

What are 3 γ:δ T cell effector functions?

Answer 26

1-Cytotoxicity
2-Immune regulation (adaptive and innate, cytokine release)
3-Tissue repair and homeostasis

Question 27

Which cells express invariant α/β T cell receptors, recognize CD1d, act as helper and cytotoxic cells, require both activated TCR and NK cell receptors to be active and are found within tissue?

Answer 27

NKT cells

*do not form memory cells

Question 28

Activated NKT cells perform what three helper and cytotoxic functions?

Answer 28

1-Lipid antigen detection
2-Cognate interactions (NK cells, B cells, Macrophages, Neutrophils)
3-Fas ligand-mediated cytotoxicity