Lecture 18

Question 1

Ig Superfamily Members

Answer 1

1. Antibodies
2. B-Cell Receptors
3. T-Cell Receptors

Question 2

Antibodies

Answer 2

Soluble B-Cell Receptors

Question 3

B-Cell Receptors

Answer 3

Membrane-Anchored Antibodies

Question 4

T-Cell Receptors

Answer 4

Membrane-Anchored MHC-ligand Receptor

Question 5

b-Pleated Sheet

Answer 5

1. Laterally packed
2. Anti-parallel or parallel
3. Peptide-backbone
4. R groups above/ below

Question 6

Immunoglobulin Domains

Answer 6

1. Hydrogen bonding along peptide backbones
2. A.A. in b-strands alternate hydrophobic or hydrophilic
   3.

Question 7

Hydrophobic

Answer 7

Residues ‘sandwiched’ between folds

Question 8

Disulfide Bonding

Answer 8

Between b-stands on opposite folds

Question 9

Antibody Molecules

Answer 9

1. Two IDENTICAL Heavy Chains
   
   • 4/5 Ig Domains per Heavy Ch.
2. Two IDENTICAL Light Chains
   
   • 2 Ig Domains per Light Ch.

Question 10

Structure of Antibody Molecules 1

Answer 10

1. Disulfide bonds covalently link the LIGHT and HEAVY chains
2. Forms HETERODIMERS

Question 11

Structure of Antibody Molecules 2

Answer 11

1. Disulfide bonds covalently link the two HEAVY chains
2. Forms HETEROTETRAMERS

Question 12

Hinge Region

Answer 12

1. Center of the HEAVY chains
2. provide ‘molecular flexibility’
   
   • multivalent antigens
3. IgA, IgD, and IgG

Question 13

Glycosylation

Answer 13

Spreads antibodies for better receptor access
– tails of antibodies

Question 14

Glycosylation 2

Answer 14

1. CH2 domains of IgA, IgD, and IgG
2. CH3 domains of IgE and IgM
3. CH-CH spacing

Question 15

Variable Region

Answer 15

Present in the NH2-terminal Ig domain of LIGHT AND HEAVY chain

Question 16

Variable Regions

Answer 16

1. Linking segments between b-strands are markedly more variable
2. Linking segments: more accommodations

Question 17

Linking Segments

Answer 17

Site responsible for specifying antigen binding

Question 18

CDR

Answer 18

Complimentary-determining region

Question 19

IgM

Answer 19

1. Primary immunoglobulin
   – “on go”
2. NO hinge region
3. Generally found in serum
4. Pentamer has 10 potential antigen binding sites

Question 20

IgD

Answer 20

1. Expressed on a subset of naïve B-Cells
2. Alternative mRNA splicing
3. Hinge Region

Question 21

IgG

Answer 21

1. Class switching
2. Hinge region
3. Most abundant immunoglobulin
4. Crosses placenta
5. “Work Horse”

Question 22

IgG: Four isotopes

Answer 22

1. IgG1
2. IgG2
3. IgG3
4. IgG4

Question 23

IgA

Answer 23

1. Class Switching
2. Hinge Region
3. Mucosal antibody

Question 24

IgA: Two isotopes

Answer 24

1. IgA1
2. IgA2

Question 25

IgE

Answer 25

1. Class switch
2. NO hinge region
3. Least abundant immunoglobulin
4. Allergic reactions

Question 26

B- Cell Receptors

Answer 26

1. Membrane-bound Ab isoform
2. ‘Activates’ B-Cells after antigen binding

Question 27

B-Cell Signal Transduction

Answer 27

Iga and Igb

Question 28

B-Cell Antigen Binding

Answer 28

CR2 (CD21) and CD19

Question 29

B-Cell Receptor Complex

Answer 29

1. Transduces antigen binding into intracellular signals
2. B-Cell Proliferation
3. B-Cell Differentiation

Question 30

B-Cell Receptor: What does it make

Answer 30

Germinal Center OR Antibodies

Question 31

T-Cell Receptor-Signaling Complex

Answer 31

1. Immunoglobulin Superfamily
2. One constant Ig region
3. One variable Ig region
4. Single transmembrane spanning domain
5. Truncated cytoplasmic domain

Question 32

gd-TCR

Answer 32

1. Often concentrated in mucosa
2. Break the binding rules
3. Can include lipid/glycolipid antigens

Question 33

V Domains

Answer 33

Three HyperVar regions
CDR

Question 34

C Domains

Answer 34

Single b sheet
Disulfide link

Question 35

TCR-CD3 Complex

Answer 35

1. zz (zeta-zeta)
2. ge (gamma-epsilon)
3. ed (epsilon-delta)

Question 36

TCR-CD3 Complex

Answer 36

Promotes complex clustering within the plane of the membrane

Question 37

CD4

Answer 37

1. Binds antigen-bound MHC II
2. Phosphorylated tail
3. Expressed in TH cells

Question 38

CD8

Answer 38

1. a-b heterodimer or a-a heterodimer
2. Binds antigen-bound MHC I
3. Expressed in TC cells

Question 39

T-Cell Receptor Complex

Answer 39

1. T-Cell Receptor
2. Signal Transduction: CD3 Complex

Question 40

T-Cell Receptors: MHC recognition

Answer 40

1. CD4 - MHC II
2. CD8- MHC I

Question 41

CD28

Answer 41

Co-receptor
- required for full activation

Question 42

T-Cell Activation Results

Answer 42

1. Transduction of binding into the cell
2. Initiation of signaling pathways
3. Immediate responses
4. Long-term responses