Antigen response and processing

Question 1

Superantigens produced by

Answer 1

1. S. enterotoxins
2. TSST - 1
3. Strep. pyogenic exotoxins

Question 2

Leukocyte adhesion deficiency genetics

Answer 2

AR absence of CD 18 (common β₂ chain)

Question 3

Step 3 in Extravasation

Answer 3

Arrest and adhesion

Interaction between integrins and Ig-superfamily cellular adhesion molecules (Ig-CAM) mediates the tight binding

Question 4

Defensins action

Answer 4

Circular peptides that form channels in bacterial cell membrane

Question 5

TH2 Cells produce

Answer 5

1. IL-4 (inhibit TH1)
2. IL-5
3. IL-6
4. IL-10 (inhibit TH1)
5. IL-13
6. TGFβ

Question 6

Step 1 in Extravasation

Answer 6

Rolling

E-selectin molecules on the endothelium bind to mucin-like adhesion molecules on the phagocyte membrane and bind the cell briefly

Question 7

Leukotriene B₄ origin

Answer 7

• Membrane phospholipids of Macrophages, monocytes, PMN, mast cells
• Lipoxygenase pathway

Question 8

Protein A of Staphylococcus aureus action

Answer 8

Impedes opxonization by binding to the Fc component of IgG

Question 9

Lysozymes action

Answer 9

Digest bacterial cell walls by cleaving peptidoglycan

Question 10

Superantigens are

Answer 10

Viral or bacterial proteins that cross-link the variable β domain of a T-cell receptor to an α chain of a MHC 2 molecule

Causes activation and proliferation leading to overproduction of IFN-γ: activates macrophage and secretion of IL-1, IL-6 and TNF-α.

Question 11

TH0 to TH2 requires

Answer 11

IL-4

Question 12

TH1 Cells stimulated by

Answer 12

Strong initial innate immune response from intracellular bacteria such as Listeria and mycobacteria and parasites such as Leishmania

Question 13

NADPH oxidase reduces

Answer 13

Oxygen to Superoxide that generates Hydroxyl FR and Hydrogen Peroxide

Question 14

IL-8 origin

Answer 14

1. Tissue mast cells
2. Platelets
3. PMN
4. Monocytes
5. Macrophage
6. Eosinophils
7. Basophils
8. Lymphocytes

Question 15

T_Reg express

Answer 15

CH25

Question 16

TH1 Cells produce

Answer 16

1. IFN-γ (Inhibit TH2)
2. TNF-β
3. IL-2

Question 17

Lactoferrin

Answer 17

Chelates iron

Question 18

TH17 express

Answer 18

Transcription factor RORgammat

Question 19

TH0 to TH17 requires

Answer 19

IL-17

Question 20

Endosomal (exogenous) pathway

Answer 20

• Involves loading of MHC 2
• MHC 2 are produced in ER an attached to invariant chain that blocks groove
• Peptide attaches and removes invariant chain in cytosol

Question 21

Endogenous pathway

Answer 21

MHC 1 synthesized in ER of the cell and proteins are loaded there

Proteins are synthesized in the cell cytosol and the peptides from the proteins are transported through the TAP complex

Question 22

Myeloperoxidase is

Answer 22

in the lysosomes and acts on Hydrogen Peroxide and Chloride ions to produce Hypochlorite

Question 23

Haptens

Answer 23

Molecules that possess only one epitope and can only occupy one combining site of the double-armed B-cell receptor

Question 24

Oxygen-independent degradative materials in lysosomes

Answer 24

1. Lysozyme
2. Defensins
3. Lactoferrin
4. Hydrolytic enzymes

Question 25

TH0 to T_Reg requires

Answer 25

IL-10

Question 26

Dangerous organism in CGD

Answer 26

1. Staph
2. Klebsiella
3. Serratia
4. Aspergillus

Question 27

TH0 to TH1 requires

Answer 27

1. IL-12
2. IFN-γ

Question 28

Step 4 in Extravasation

Answer 28

Transendothelial migration

Phagocyte extends pseudopodia through the vessel wall and extravasates into the tissue

Question 29

Step 2 in Extravasation

Answer 29

Activation by chemoattractants

Chemokines such as IL-8, C5a and N-formyl peptides trigger a G-protein mediated activating signal

Induces a conformational change in integrin molecules in the phagocyte membrane that increases their affinity for IG