Quiz 3

Question 1

What 4 things make adaptive immunity different than innate?

Answer 1

1. antigen specificity
2. diversity
3. memory
4. non-self recognition

Question 2

____ cells are involved in Humoral immunity while ___ are involved in Cell-mediated immunity

Answer 2

B cells – humoral
T cells – cell mediated

Question 3

B cell receptors are also called ___________

Answer 3

immunoglobulins

Question 4

What is a way B and T cells increase their diversity to antigens?

Answer 4

DNA chromosomal rearrangment

Question 5

B and T cell receptor genes are spliced/rearranged BEFORE or AFTER transcription?

Answer 5

rearranged before

Question 6

What is the germline configuration?

Answer 6

gene segment region BEFORE DNA rearrangement

Question 7

What are the 4 segments for B and T cell receptor rearrangment?

Answer 7

1. variable (V)
2. diversity (D)
3. joining (J)
4. constant (C)

Question 8

What genes go through V(D)J somatic recombination?

Answer 8

B and T cell receptor genes

Question 9

The __________ of the enzymes involved in VDJ recombination increases diversity

Answer 9

imprecision

Question 10

What are the 2 domains on T cell receptors?

Answer 10

constant
variable

Question 11

What holds the alpha and beta chain together on T cell receptors?

Answer 11

disulfide bond

Question 12

Describe the look of T cell receptors?

Answer 12

typically an alpha and beta chain
can be gamma and delta instead

Question 13

What segments are rearranged in T cell receptors with alpha or gamma?

Answer 13

V
J

Question 14

What segments are rearranged in T cell receptors with beta or delta?

Answer 14

V
D
J

Question 15

_________ begin as receptors on B cells but after activation they become plasma cells and are secreted

Answer 15

antibodies

Question 16

Describe the look of B cell receptors (antibodies)

Answer 16

2 heavy chains
2 light chains

Question 17

The light chain on antibodies links _____ and ______ segments

Answer 17

V
J

Question 18

The heavy chain on antibodies links _____ then ______ segments

Answer 18

DJ
V

Question 19

each “arm” on B and T cell receptors that contain VDJ segments rearrange __________

Answer 19

independently of one another

Question 20

What does RSS do in VDJ recombination?

Answer 20

recognition site for RAG to bind to DNA

Question 21

What does RSS ensure?

Answer 21

recombination only occurs in gene segements encoding for B and T cell receptors

Question 22

What are RSSs made of?

Answer 22

heptamer
nonamer
23 or 12 spacer

Question 23

Where is RSS located relative to V segments?

Answer 23

downstream end

Question 24

Where is RSS located relative to D segments?

Answer 24

flanks it

Question 25

Where is RSS located relative to J segments?

Answer 25

upstream end

Question 26

What is the 12/23 rule?

Answer 26

only 12RSS can combine with 23 RSS to prevent joining of incorrect segments

Question 27

Where does RAG1/2 bind to RSS?

Answer 27

randomly

Question 28

What does RAG1/2 do?

Answer 28

cleaves DNA at heptamer sequences of 12 RSS and 23RSS

Question 29

What is a signal joint?

Answer 29

trashed circular DNA excised during VDJ recombination

Question 30

What is a coding joint?

Answer 30

functional portion of DNA

Question 31

What is the coding joint made of?

Answer 31

alpha or gamma chain and light chain

Question 32

What does NHEJ do?

Answer 32

repair that produces the coding and signal joint

Question 33

What does Artemis do?

Answer 33

cleaves DNA hair pin to create overhangs

Question 34

What are P nucleotides?

Answer 34

nucleotides associated with the overhangs

Question 35

What are DNA overhangs filled with and by what?

Answer 35

P nucleotides NHEJ

Question 36

What is a variable segemnt?

Answer 36

DNA formed when overhangs are filled and repaired

Question 37

What does Tdt do?

Answer 37

removes P nucleotides and replaces them with N nucleotides (increases diversity)

Question 38

What is the final resulting strand named after recombination?

Answer 38

coding strand

Question 39

VDJ recombination involves which chains?

Answer 39

beta or gamma and heavy chain

Question 40

VJ recombination involves which chains?

Answer 40

alpha or gamma and light chain

Question 41

In VDJ recombination what is the order that segments link?

Answer 41

D links to J then V links to DJ

Question 42

What are the 2 diversity mechanisms of VDJ recombination?

Answer 42

1. joining of segments 2. junctional flexability (splicing isnt the same every time)

Question 43

What 2 mechanisms all B cells to have additional diversity?

Answer 43

class switching hyper mutation

Question 44

What is AID in B cells?

Answer 44

converts cytosine into uracil causing mutations that have to be repaired = increasing diversity

Question 45

What Ig's don't require class switching to occur?

Answer 45

IgM and IgD

Question 46

What B cell mechanism changes antigen binding affinity?

Answer 46

somatic hypermutation

Question 47

What is class switching?

Answer 47

When B cells change from IgD or M to a different class

Question 48

class switching produces an antibody with the _______ antigen specificity

Answer 48

same

Question 49

T/F: class switching and somatic hypermutation uses AID

Answer 49

true

Question 50

What is CDRs (complementary determining regions) in B cell affinity maturation?

Answer 50

location where mutations are introduced to increase diversity

Question 51

What are 3 possible mechanisms of somatic hypermutation?

Answer 51

1. DNA replication (point mutation) 2. base excision repair 3. mismatch repair (point mutation)

Question 52

What is the cause of most antigen diversity?

Answer 52

VDJ recombination

Question 53

HLA class I is expressed on what cells?

Answer 53

nucleated

Question 54

HLA class II is expressed on what cells?

Answer 54

antigen presenting cells (B cells, macrophages, DCs)

Question 55

What does HLA class I present to?

Answer 55

cytotoxic T cells

Question 56

What does HLA class II present to?

Answer 56

helper T cells

Question 57

What type of pathogen does HLA class I deal with?

Answer 57

intracellular

Question 58

What type of pathogen does HLA class II deal with?

Answer 58

extracellular

Question 59

What are the 4 domains of HLA class I

Answer 59

alpha 1 alpha 2 alpha 3 beta 2

Question 60

Where is the binding cleft in HLA class I?

Answer 60

alpha 1 and 2

Question 61

What chromosome is HLA genes on?

Answer 61

6

Question 62

What is the structure of HLA class II?

Answer 62

heterodimer (alpha 1, alpha 2 and beta 1 and beta 2)

Question 63

Where is the binding cleft located on HLA class II?

Answer 63

alpha 1 and beta 1

Question 64

What class of HLA is more specific in what it will bind to?

Answer 64

class II

Question 65

What is the most diverse gene cluster?

Answer 65

HLA

Question 66

For HLA, gene variation is at the __________ level

Answer 66

population

Question 67

______ facilitate organ transplant rejection

Answer 67

HLA

Question 68

Loading of peptides for HLA class II occurs where?

Answer 68

vesicle fused with phagolysosome

Question 69

Loading of peptides for HLA class I occurs where?

Answer 69

ER