Humoral Immunity Part 1 (Exam 1)

Question 1

What fraction of serum are antibodies found in

Answer 1

gamma globulin

Question 2

What is the major line of defense against bacteria and extracellular pathogens

Answer 2

antibodies

Question 3

How many domains do light chains have

Answer 3

2 (1 V and 1C)

Question 4

How many domains do heavy chains have

Answer 4

4-5 (1V and 3-4 C)

Question 5

What are the heavy chain classes

Answer 5

mu, gamma, delta, alpha, epislon

Question 6

What are the light chain classes

Answer 6

kappa and lambda

Question 7

What gene segments compose the variable region of the light chain

Answer 7

V and J (variable and joining)

Question 8

What gene segments compose the variable region of the heavy chain

Answer 8

VDJ (variable, diversity, joining)

Question 9

What allows for the large amount of diversity in the variable region of antibody

Answer 9

gene rearrangement

Question 10

Describe the chromosomal arrangement of heavy and light chains

Answer 10

Heavy: on same chromosomes

Light chain: different chromosomes

Question 11

What cells does antibody gene rearrangement occur

Answer 11

B and T cells as they are only cells with recombinase

Question 12

What region of heavy chain is capable of rearrangement

Answer 12

V region

Question 13

Describe the process of heavy chain rearrangement

Answer 13

First: recombinase will pick a D and J and splice out all the middle stuff and combine them

Second: recombinase will pick a V and splice out stuff in between

Question 14

What genes encode recombinase

Answer 14

Rag1 and Rag2 genes

Question 15

What enzyme complex facilitates rearrangement

Answer 15

recombinase

Question 16

Where are light chains and heavy chains located in regard to chromosomes

Answer 16

light chains on separate chromosomes. Heavy chains on same chromosomes

Question 17

What chain will be made first in B and T cells

Answer 17

heavy chain

Question 18

How does recombinase lead to diversity in antibodies

Answer 18

will make different combinations each time

Question 19

What area of the C region is always made first

Answer 19

mu

Question 20

What is required in order for a heavy chain to switch classes

Answer 20

must come in contact with an antigen

Question 21

Explain the process of heavy chain rearrangement

Answer 21

D and J are joined first by recombinase

V is joined next by recombinase

Combination of DJ and V will create a variable region

Question 22

Describe the process of light chain rearrangement

Answer 22

Recombinase enters and picks a V and a J splices out the stuff in between

Question 23

WHat will happen if there is a mutation in Rag1 or Rag2

Answer 23

lack of recombinase
Would not be able to have antibodies
Results in SCID

Question 24

What is the function of terminal deoxynucleotidal transferase

Answer 24

messes with DNA polymerize

an enzyme that inserts random nucleotides between D and J and VDJ segments randomly before they are sealed together

Question 25

What does terminal deoxynucleotidal transferase allow

Answer 25

for different binding specificities that will affect the binding of the antibody to the antigen to increase diversity

Question 26

When is TDT expressed

Answer 26

early in B and T cell development

Question 27

How can TDT be used clinically

Answer 27

In certain cases of leukemia it can be utilized as a marker

Question 28

What results from somatic hypermutation

Answer 28

affinity maturation which produces increased binding specificy on antibodies

Question 29

When does affinity maturation occur

Answer 29

only in B cells after contact with antigen

Question 30

What is the function of allelic exclusion

Answer 30

Excludes expression of less productive specificity allele to insure antigenic specificity

Question 31

What genes will be expressed in H chain and L chains in a B cell

Answer 31

genes from only one chromosome for H and one chromosome for L

Question 32

What are the immunoglobulin classes

Answer 32

``` IgA IgE IgM IgD IgG ```

Question 33

What is the heavy chain associated with IgA

Answer 33

alpha

Question 34

What is the heavy chain associated with IgE

Answer 34

epsilon

Question 35

What is the heavy chain associated with IgM

Answer 35

mu

Question 36

What is the heavy chain associated with IgD

Answer 36

delta

Question 37

What is the heavy chain associated with IgG

Answer 37

gamma

Question 38

What is the predominant antibody made during the primary immune response

Answer 38

IgM

Question 39

What is the first antibody made in neonates

Answer 39

IgM

Question 40

What pathway can IgM activate

Answer 40

classical complement pathway

Question 41

What form does IgM have in a B cell and in serum

Answer 41

monomer: in B cell Pentamer: in serum

Question 42

When is IgM secreted as a pentamer

Answer 42

when B cell turns into a plasma cell

Question 43

What is avidity

Answer 43

number of binding sites

Question 44

What is the avidity of IgM

Answer 44

high

Question 45

How many binding sites for antigens does IgM have

Answer 45

10

Question 46

What is the affinity of IgM

Answer 46

low affinity

Question 47

WHat causes the low affinity of IgM

Answer 47

has not undergone somatic hypermutation yet

Question 48

What holds IgM together

Answer 48

J chain

Question 49

What are the levels of IgD in plasma

Answer 49

low

Question 50

Where are IgD found

Answer 50

membrane of B cells

Question 51

What two Igs can display co-expression

Answer 51

IgD and IgM on the same cell (same variable region and different constant regions)

Question 52

What does class switching to IgG occur through

Answer 52

IFN gamma and Th1 cells

Question 53

What immune functions are exclusively undergone by IgG

Answer 53

opsonization ADCC crossing of the placenta

Question 54

What immune function is shared by IgG and IgM

Answer 54

neutralization | activation of classical complement

Question 55

What is the affinity of IgG

Answer 55

high due to having had somatic hypermutation

Question 56

Which antibody will predominate during a secondary/memory response

Answer 56

IgG

Question 57

What is the predominant antibody in the serum

Answer 57

IgG

Question 58

What are the subisotypes of IgG

Answer 58

1-4

Question 59

Why might you be concerned if an expectant mother comes to your office with IgM antibodies to rubella

Answer 59

rubella is capable of crossing the placenta and infecting the fetus IgM means it was the mother's first exposure. She will not have any IgG which is capable of crossing the placenta and protecting the fetus

Question 60

What causes class switching in IgA

Answer 60

TGF beta mainly | IL4, IL10, iNOS, retinoic acid

Question 61

Where does class switching of IgA predominately occur

Answer 61

mucosa

Question 62

What is the predominant antibody in secretions

Answer 62

IgA

Question 63

What form is IgA present as in secretions

Answer 63

dimer

Question 64

What is the avidity of IgA

Answer 64

higher than IgM

Question 65

What protects IgA in secretion

Answer 65

secretory piece. Enzymes that try to degrade IgA will bind to the secretory piece instead

Question 66

How is IgA transfered to lumen mucosa

Answer 66

Poly-Ig receptors bind to the J chain and transfer IgA into the lumen

Question 67

What type of immunoglobulin will be seen in breast milk

Answer 67

IgA

Question 68

What will IgE levels be in plasma

Answer 68

low

Question 69

What is the main target of IgE

Answer 69

parasites/ worms

Question 70

Which Ig is responsible for allergies

Answer 70

IgE

Question 71

What cells are the target of IgE

Answer 71

mast cells | basophils

Question 72

Which Ig can lead to type 1 hypersensitivity reactions

Answer 72

IgE