Immunology - 21

Question 1

Does the epitope on a B cell receptor have to be sequential or continuous?

Answer 1

It may be sequential or discontinuous but it must be in an accessible location within the folded protein structure. It may be protein, polysaccharide, lipid, nucleic acid

Question 2

Does the epitope on a T cell receptor have to be sequential or continuous?

Answer 2

• Must be sequential because the protein is processed by the cell (chopped into peptides so not a native form)
• does not need to be on antigen surface or external face of the protein (can be a nuclear or cytoplasmic protein)
• can only be recognized by the TCR with proper presentation and is almost always a protein

Question 3

The BCR/antibody have a different epitope than the TCR. Do they recognize the same antigen?

Answer 3

If the B cell and T cell are working together (they are activated in response to the same pathogen) then yes, they recognize the same antigen but different epitopes. If the B cell and T cell do not work together in the immune system, then they don’t recognize the same antigen

Question 4

Which receptor has a membrane anchor sequence at the end of the heavy chain, BCR or TCR?

Answer 4

BCR

Question 5

All the antibodies and the BCR made by one cell or differentiated from it bind (the same or different) antigen?

Answer 5

same

Question 6

In the early steps of B cell development, what is development regulated by when going from Pro-B to naïve mature B cell?

Answer 6

Development is regulated by antibody gene rearrangement

Question 7

What is antibody gene rearrangement?

Answer 7

The genetic regions have to undergo a rearrangement process to produce a viable antibody protein

Question 8

When making the BCR heavy chain, the variable region of the heavy chain antibody proteins is produced by linking together three different regions of the DNA. Which are these?

Answer 8

The V, D, and J genes are linked together to form the complete variable region (DNA sequence) of the heavy chain

Question 9

What does heavy chain rearrangement provide?

Answer 9

Diversity

Question 10

What are the steps from stem cell to mature B cell?

Answer 10

• Stem cell
• Pro-B
  heavy chain rearrangement takes place
• Pre-B
• immature B (with IgM) - light chain rearrangement
• mature B (with IgM and IgD) - travels to secondary lymphoid tissue