Lecture 23

Question 1

Adaptive immunity has:

Answer 1

memory

Question 2

The affinity of B cells towards antigens:

Answer 2

Increases with time and persistence of antigen

Question 3

Which adaptive immunity response is stronger and more rapid?

Answer 3

Secondary compared to primary

Question 4

Adaptive immunity relies on:

Answer 4

Gene arrangement or recombination

Question 5

What is a transposase?

Answer 5

The enzyme that operates on the transposase

Question 6

The ancient transposases in your genome are called

Answer 6

Recognition Activation Sequences (RAG1 or RAG2)

Question 7

Recognition sequences (RS) are

Answer 7

Base pair sequences found at the ends of any gene segments that rearranges - RS are the substrate for RAG1 and RAG1 directed combination.

Question 8

Antibodies are formed from:

Answer 8

repeated Ig domains.

Question 9

Two antiparallel b-pleated sheets are joined in the middle by:

Answer 9

a disulphide bond.

Question 10

The antibody molecule consists of

Answer 10

4 protein chains and repeating Id domains.

Question 11

How many L domains and how many H domains

Answer 11

2 domains in L and 4-5 in H

Question 12

Antibody protein structure:

Answer 12

L–s-s–H–s-s–H–s-s–L. The two H chains are disuplhide linked.

Question 13

The antigen binding sties are located at the ::

Answer 13

tip of the two arms. Formed from the N terminal domains of the L and H chains.

Question 14

The effector region:

Answer 14

invariant, bound by Fc receptors and complement component C1.

Question 15

IgM

Answer 15

The default Ig made by all naive B cells.

Question 16

The membrane(monomer) form of IgM is:

Answer 16

the B-cell antigen receptor (BCR)

Question 17

The soluble (pentamer) has how many antigen binding sites

Answer 17

10

Question 18

Affinity:

Answer 18

When the sum of attractive molecular forces at two surfaces exceeds the repulsive forces, there is affinity

Question 19

Avidity:

Answer 19

Avidity results from multiple affinity contacts. Like velcro.

Question 20

IgG:

Answer 20

Gene name Y, activates complement, placental transfer, 20mg/ml

Question 21

IgM

Answer 21

Gene name U, activates complement, membrane bound form

Question 22

IgA

Answer 22

Gene name A, secreted at mucosal surfaces

Question 23

IgD

Answer 23

Membrane bound form

Question 24

IgE:

Answer 24

High affinity receptor on mast cells

Question 25

Amino acid variation is found in:

Answer 25

3 regiosn called the complementartity determining regions (CDR). These are the 3 loops that connect the strands in the 1st domains of the H and L chains.

Question 26

How many identical antigen binding sites?

Answer 26

2

Question 27

Light chain locus has no ___ segments

Answer 27

D

Question 28

RAG1 and RAG2 (Recombination activation gene) are responsible for:

Answer 28

Rearrangement and are only active in B and T lymphocytes

Question 29

In H gene locus:

Answer 29

D to J then V to D. Intervening DNA is lost.

Question 30

In Lk gene locus

Answer 30

V to J

Question 31

Imprecise joining results in:

Answer 31

Massive amino acid diversity in the CDR3 loop on the antigen receptor

Question 32

Receptor cominbations are made ___

Answer 32

as randomly as possible

Question 33

Each B cell is generated before birth with a ___

Answer 33

unique B cell receptor

Question 34

B cells encounter antigen in ___

Answer 34

lymph nodes/

Question 35

Somatic hypermutation of the Ig gene results in:

Answer 35

Some clones with higher antigen receptor affinity.

Question 36

After successive rounds of somatic hypermutation of the Ig gene:

Answer 36

The mature B cell becomes a plasma cell secreting soluble Ig.

Question 37

Some B cells reside in lymph nodes as ___

Answer 37

long-term memory cells.

Question 38

Clostridium tetani is:

Answer 38

A common soil bacterium that proudces tetanus toxin (TT)

Question 39

TT is:

Answer 39

a neurotoxin that binds to the presynaptic membrane of the neuromuscular junction and causes lockjaw

Question 40

Vacciniating with Tetanus Toxin does what:

Answer 40

Drives affinity maturation of those IgM antibodies into high affinity IgG antibodies that block TT receptor binding.

Question 41

The Ig and TcR gene loci are segmented into:

Answer 41

variable, diversity and joining regions.

Question 42

Each naive B cell represents:

Answer 42

a unique antigen specificity

Question 43

Antigen drives:

Answer 43

Clonal selection and expansion in lymph node follicles.

Question 44

What is the reason why immunization works?

Answer 44

Affinity maturation