Antigen Receptor B-Cell Development Lecture 5 Flashcards Preview

Host Defense > Antigen Receptor B-Cell Development Lecture 5 > Flashcards

Flashcards in Antigen Receptor B-Cell Development Lecture 5 Deck (20):
1

Early Pro-B cell

Heavy chain DJ rearrangment

2

Late Pro-B

Heavy chain V-DJ rearrangement

3

Large Pre-B

mu chain transiently at surface as part of pre-B-cell receptor. mainly intracellular
-mu heavy chain that is made binds a surrogate light chain and takes it to the surface

4

small pre-B cell

V-J rearranging
-intracellular mu chain

5

immature B-cell

IgM expressed on cell surface

6

Mature B cell

IgD and IgM made from alternatively spliced Heavy chain transcripts

7

What does RAG recognize and what does it do?

RAG recognizes RSS and cleaves the DNA between RSS and J or RSS and V, come together and get ligated

8

What is a brec

B cell Recombination excision circle

9

How do you get secreted IgM and membrane IgM with the same VDJ region? And IgM and IgD with the same VDJ region?

Alternative RNA splicing

10

Does class switch happen in the bone marrow?

NO
-in the periphery, using aid mediated cleavage

11

How do we get such a large repertoire of Ig?
3 reasons

1. combinatorial V(D)J gene joining
2. N nucleotide addition by TdT
3. Combinatorial association of H and L chains

12

What does TdT do?

randomly puts on nucleotides to either side
can be anywhere from 1 to 30
changes antibody site-doesn't require any additional DNA

13

What are three ways these VDJ gene rearrangements may react with self, what happens to them?

1. multivalent self molecule
2. soluble self molecule
3. no self reaction

14

What are three ways these VDJ gene rearrangements may react with self, what happens to them?

1. multivalent self molecule
-clonal deletion-apoptosis or receptor editing
2. soluble self molecule
-migrates to periphery-low mu expression-anergic bcell
3. no self reaction
-migrates to periphery-mature b cell

15

How is a multivalent self molecule given a second chance? (self-reactive b-cell)

receptor editing
-up regulate RAG-can rearrange again
-this can only happen in the light chain because in the heavy chain all the other d's are deleted

16

How is a multivalent self molecule given a second chance? (self-reactive b-cell)

receptor editing-light chain
-up regulate RAG-can rearrange again
-this can only happen in the light chain because in the heavy chain all the other d's are deleted

17

Is there a structural similarity of T cell receptor and Ig?

yes
T-cell receptor looks like Fab
Alpha and beta both have variable regions where the antibody interacts

18

Is there a structural similarity of T cell receptor and Ig?

yes the T cell receptor looks like the Fab part on the Ig

-both alpha and beta regions on the t-cell have a variable region where the antibody interacts

-antibody (variableL and variableH) and T cell (variable alpha and variable beta)

19

Is there a structural similarity of T cell receptor and Ig

yes the T cell receptor looks like the Fab part on the Ig

-both alpha and beta regions on the t-cell have a variable region where the antibody interacts

-antibody (variableL and variableH) and T cell (variable alpha and variable beta)

20

Do T cells use TRECs like BRECs and RSS mediated by RAG?

yes