Exam Two

Question 1

Which type of mature B cell responds to a protein antigen?

Answer 1

B-2 B cells and MZ B cells

Question 2

V-D-J rearrangement occurs in___________

Answer 2

B cells and T cells

Question 3

True or False: Kappa and lambda light genes are located on the same chromosome.

Answer 3

FALSE

Question 4

Which TCR gene variable regions possess a “J” segment?

Answer 4

alpha, beta, and gamma

Question 5

If you stain DCs with TAP1 antibody, which intracellular compartment would exhibit positive?

Answer 5

Rough Endoplasmic Reticulum, or Rough ER

Question 6

Which of the following cell types would be LEAST likely to express MHC class II?
  A. Mast cells 
  B. B cells 
  C. Dendritic cells 
  D. Macrophages

Answer 6

Mast cells

Question 7

True or False: MHC polymorphisms occur in the peptide-binding groove

Answer 7

TRUE

Question 8

Activated membrane-bound IgM or secreted IgM is determined by _____

Answer 8

alternative splicing of pre-mRNA

Question 9

What happens when HSC is cultured in the presence of Notch ligand?

Answer 9

The HSC differentiates into T cells rather than B cells.

Question 10

BCR and TCR VDJ recombination is an event occurring at what level?

Answer 10

the DNA level

Question 11

True or False: Anchor residues at both ends of the peptides on MHC class I molecules

Answer 11

TRUE

Question 12

What kind of diversity do mature B-1 cells show in their V-region?

Answer 12

High or low, depending on the active infection

Question 13

Where do T-lymphocyte progenitors originate?

Answer 13

Bone marrow

Question 14

What is only expressed in the loci of Ig heavy chain?

Answer 14

D (diverse)

Question 15

If you have an HLA a/b MHC haplotype and 2 siblings, your chances of having the identical haplotype as your sibling are

Answer 15

1:4

Question 16

What kind of signal do cells need to survive during positive selection?

Answer 16

intermediate signal

Question 17

Where are B lymphocytes generated in? Where do they further mature?

Answer 17

Bone marrow | spleen

Question 18

True or False: T cells can recognize MHC molecules

Answer 18

TRUE

Question 19

What happens to autoreactive cells that escape the thymus?

Answer 19

They attack self-tissues

Question 20

What is the most developed type of B cell?

Answer 20

Pro-B cell

Question 21

When thymocytes interact with MHC II to generate a continuous signal, what cell type is then generated?

Answer 21

CD4+ T cells

Question 22

Which TCR gene variable region possesses a “D” segment?

Answer 22

δ

Question 23

Which is the most abundant light chain of an antibody in mice?

Answer 23

Kappa

Question 24

What is T cell self-MHC restriction?

Answer 24

This is when a T-cell clone only recognizes foreign peptides when presented by self-MHC

Question 25

True or False: B cells, like T cells, are MHC class restricted.

Answer 25

FALSE

Question 26

What is the function of a CD1 cell?

Answer 26

display lipid antigens

Question 27

What is the function of a CD3 cell?

Answer 27

T cell coreceptor complex

Question 28

What is the function of a MHC class I cell?

Answer 28

binds to CD8 TCR

Question 29

What is the function of a MHC class II cell?

Answer 29

binds to CD4 TCR

Question 30

What is the function of a Treg cell?

Answer 30

regulate APC cell antigen presentation

Question 31

Which MHC has peptide-binding domain alpha1/beta1?

Answer 31

MHC II

Question 32

Which MHC has peptide-binding domain alpha1/alpha2

Answer 32

MHC I

Question 33

Positive selection...

Answer 33

...results in self-MHC restriction

Question 34

Negative selection...

Answer 34

...ensures self-tolerance

Question 35

TNF family cytokines are found in...

Answer 35

MHC III

Question 36

Allelic exclusion

Answer 36

the mechanism that ensures only one heavy-and-light-chain allele are transcribed and translated from a B cell

Question 37

Professional APCs

Answer 37

These antigen-presenting cells are specifically MHC class II-expressing cells, including DCs, macrophages, and B cells.

Question 38

Clonal anergy

Answer 38

A method of self-tolerance where autoreactive T cells are inactivated through negative selection

Question 39

Receptor editing

Answer 39

the reactivation of recombination machinery on autoreactive receptors in light chains

Question 40

mRNA splicing

Answer 40

the cause of IgM and IgD antibodies being expressed by mature B cells. Controls whether membrane-bound or secreted IgM is produced by removing the intervening spacer between the VDJ and C regions

Question 41

Cross-presentation

Answer 41

The presentation of exogenous antigens on MHC Class I molecules (mainly DCs) to CD8 T cells.

Question 42

Homozygous

Answer 42

having the same alleles at a particular gene locus on homologous chromosomes

Question 43

RSS “12/23 Rule”

Answer 43

The rule that a 12 bp recombination signal sequence (RSS) must pair with a 23 bp RSS for V(D)J recombination to occur

Question 44

Self-tolerance

Answer 44

The ability for the immune system to recognize and allow for self-produced antigens while avoiding autoimmune diseases from developing. Examples include clonal deletion, arrest, anergy, and editing.

Question 45

Describe the five mechanisms that generate BCR diversity in naïve B cells.

Answer 45

1. Multiple gene segments that can vary in order 2. Templated P nucleotide addition between joints from asymmetrical cleaving of hairpin structures 3. Exonuclease trimming that results in losing nucleotides and changing reading frames 4. Non-templated N nucleotide addition that adds in random nucleotides between joints 5. Diversity generated with the way in which heavy chains pair with varying light chains

Question 46

Describe the major steps of class I Endogenous pathway presentation.

Answer 46

Peptides, generated by proteasomes, are transported from the cytosol to the rough endoplasmic reticulum (RER) where TAP molecules move the fragments. At this point, MHC class I molecules from RER ribosomes anchor in the RER membrane after their translation.

Question 47

Describe the models that may regulate T cell lineage (SP T cell) commitment.

Answer 47

Instructive model: The co-engagement of TCR/CD4 and TCR/CD8 generate signals that instruct T cells which lineage to fully commit to Stochastic model: Positively-selected thymocytes randomly down-regulate CD4/CD8 with only those with the "correct" coreceptor receiving the signal to continue development Kinetic signaling model: This model has two branches: Cells committing to the CD4 lineage if they receive a continuous signal, or committing to CD8 lineage of the stimulation signal is interrupted