Cell-Mediated Cytotoxicity - Diebel

Question 1

How is humoral immunity mediated and what does humoral immunity protect?

Answer 1

Mediated by Antibody

Protects extracellular environment

Question 2

How is cell mediated immunity effective?

Answer 2

Recognizes pathogen infected cells or cells that have undergone genetic alterations and kills them

Question 3

What does cell-mediated cytotoxicity provide defenses against?

Answer 3

Viruses
Bacteria
Parasites

Question 4

What are antigen non-specific effector cells?

Answer 4

NK Cells (Macrophages, Neutrophils, Eosinophils)

Question 5

What are antigen specific effector cells?

Answer 5

CD8+ T-Cells

CD4+ T-Cells

Question 6

What does an NK cell respond to in order to mediate cytotoxicity?

Answer 6

Lack of MHC Class I Molecule

Stress Induced Activating Ligand

Question 7

What does a CD8+ T-Cell respond to in order to mediate cytotoxicity?

Answer 7

Antigen recognition as Non-Self

Question 8

CTL-Precursors lack the ability to do what?

Answer 8

Proliferate and Kill

Question 9

How is a CTL-P activated?

Answer 9

Licensed APCs

Question 10

How are APCs licensed?

Answer 10

Th1 or Th17 CD4+ T-Cells

PAMPs on TLRs

Question 11

What signals from the APC is required to activate a CTL-P?

Answer 11

Antigen presented on MHC Class I
CD28 :: CD80/86
IL-2 from Th1 or Th17
IL-4, IL-13, IL-15

Question 12

Describe the alpha receptor on a naive CD8+ T-Cell

Answer 12

Low affinity IL-2 Receptor

Question 13

Describe the CD25 receptor

Answer 13

High affinity Gamma, Beta and Alpha IL-2 Receptor

Question 14

What do naive CTL-P cells express?

Answer 14

Low levels of CD44 and LFA-1
High levels of L-Selectin and CCR7 (retention in lymph node)
NO IL-2

Question 15

What do effector CTL cells express?

Answer 15

High Affinity IL-2R (CD25) and IL-2
Low levels of L-Selectin and CCR7
High levels of CD44 and LFA-1

Question 16

What do memory CTL cells express?

Answer 16

Low levels of IL-2

Question 17

CTL LFA-1 binds tightly to…

Answer 17

ICAM on target cell

Question 18

Environmental IL-4, IL-12, and IL-15 induces the CTL to produce what?

Answer 18

Perforin and Granzymes

Question 19

How do granzyme molecules activate apoptosis?

Answer 19

Cleavage of caspases (Bid and Procaspase-3)

Question 20

What are the 3 mechanisms that CTLs and NK Cells can kill by?

Answer 20

1) Perforin and Granzyme Secretion
2) Fas-Fas Ligand binding
3) TNF production and secretion

Question 21

CTL CD2 binds to…

Answer 21

LFA-3

Question 22

What type of cells kill virus infected cells, intracellular pathogen-infected cells, and tumor cells?

Answer 22

NK Cells

Question 23

What cytokines stimulate NK cell activity?

Answer 23

IFN-a
IFN-B
IFN-y
TNF-a
IL-15

Question 24

Differentiate between CD56 high and low cells.

Answer 24

NK Cells with CD56 high are target cell killers.

NK Cells with CD56 low are cytokine (IFN=y) releasing.

Question 25

What do NK cells express on their surface?

Answer 25

CD16 (FcyRIIIA) and NKRs

Question 26

What do Lectin-Like Receptors (NKG2 family) do on NK Cells?

Answer 26

Binds HLA-E and MHC Class I-like molecules (NKG2D) -Associated with CD94 ACTIVATING

Question 27

What do immunoglobulin-like receptors (KIR) do on NK Cells?

Answer 27

Killer Cell Immunoglobulin-Like Receptors bind MHC Class I Molecules INHIBITORY

Question 28

NK Cells recognize what when looking to kill target cells?

Answer 28

Cells that MASK the presence of foreign antigen on MHC Class 1

Question 29

CTLs recognize what when looking to kill target cells?

Answer 29

Cells that EXPRESS foreign antigen on MHC Class I

Question 30

What effector cells are associated with Antibody-Dependent Cell Mediated Cytotoxicity (ADDC)?

Answer 30

``` NK Cells Macrophages Monocytes Neutrophils Eosinophils ```

Question 31

What effector cells release cytolytic enzymes for cell killing?

Answer 31

Macrophages Eosinophils Neutrophils

Question 32

What effector cells release TNF for cell killing?

Answer 32

NK Cells Monocytes Macrophages

Question 33

What effector cells release Perforin for cell killing?

Answer 33

NK Cells | Eosinophils

Question 34

What effector cells release Granzyme for cell killing?

Answer 34

NK Cells

Question 35

What are the 4 Antibody Effector Functions?

Answer 35

1) Virus and Toxin Neutralization to prevent pathogen-host binding 2) Opsonization to facilitate phagocytosis 3) Complement fixation and formation of the membrane attack complex to facilitate phagocytosis or lysis 4) Antibody-Dependent Cell Mediated Cytotoxicity (ADCC) to facilitate NK-induced apoptosis

Question 36

What are the 5 functions of Fc Receptors?

Answer 36

1) Degranulation 2) Opsonization of Bacteria and Phagocytosis 3) Maintaining serum antibodies 4) ADCC 5) Transcytosis into secretions