Bloodbank Lecture 4 B CELL Adaptive Immunity

What is the first step of B cell maturation?

Pro-B cell

What are the 2 main things happening in the Pro-B cell stage (1st)?

1. Genes preparing to build the antibody

2. Build the HEAVY CHAIN of the antibody first

What is the second step of B cell maturation?

Pre-B Cell

What is the main thing occurring in the Pre-B cell stage (2nd)?

u Heavy Chain + Ig-alpha and Ig-beta chains form the pre-Bcell receptor on the cell surface

Which 3 components make up the pre B cell receptor?

uHEAVY CHAIN + Ig-alpha chain + Ig-beta chain

What is the third step of B cell maturation?

Immature B cell

What are the two main things happening in the Immature B cell stage (3rd)

1. pre-BCR gets turned into a functional BCR

2. Self antigen check - B cells with self antigen receptors = destroyed

What does the functional BCR contain?

two light chains and two heavy chains of IgM

IgM is the first antibody made

Which part of the BCR is specific?

Variable region

BCR is the antigen receptor

What is the fourth step of B cell maturation?

Mature B cell

Where does the Mature B cell phase occur (4th final)?

Spleen

Which B cells remain in the spleen?

Marginal B cells

Quickly responding to bloodborne pathogens

Which B cells migrate to the lymph nodes (majority)?

Follicular B cells

Which two antibody classes are expressed on the surface of mature B cells?

IgM and IgD

Which cell type actually produces antibodies?

Plasma Cells

Mature B cell is stimulated by antigen to differentiate into a plasma cell

What are the two ways that a Bcell can respond?

T-cell dependent

T-cell independent

What happens in the T-cell dependent style of B-cell response?

Th helps → memory is generated + class switching

What happens in the T-cell independent style of B-cell response?

NO Th HELP

Only IgM is produced + NO MEMORY