B lymph Flashcards
Where do B cells develop and migrate?
Bone marrow and
migrate to peripheral
lymphoid organs, where
they can be activated by
antigens
What activates B cells
antigens
What is somethig that progeitor B cells in bone marrow do to their Igs?
Rearrange their Ig genes, dependent on interactions with bone marrow stromal cells
What type of cell surface Ig do immature B cells have? What gets them removed?
-Cell surface IgM
-→ immature B cells are removed
if they are strongly stimulated by Ag from the repertoire by receptor editing or by
apoptosis
Why is apoptosis necessary for B cells?
remove many self-reactive B cells from repertoire
Where do B cells emerge into and what Igs do mature B cells express
→ surviving immature
B cells emerge into the periphery and mature to express IgD as well as IgM
Activated B cells proliferate and differentiate into
Ab-secreting plasma cells and long-lived memory
cells
What do common
lymphoid progenitor cells
express and is stimulated by?
express- IL-7R
Stimulated by- IL-7
produced by bone
marrow stromal cells →
pro-B cell → pre-B cell
→ immature B cell
What does B-cell development begin by
rearrangement of the heavy-chain locus
What defines early pro-B cells
-D-JH gene segment rearrangement starts in common lymphoid progenitor and occurs mostly in early pro-B cells)
Late pro B cells have what kind of rearrangement
VH to DJH rearrangement)
Large pre-B cells express
complete Ig heavy chain as part of pre-B-cell receptor signaling via Iga and Igβ
What is expressed on B cells that lets you know it is immature?
IgM on cell surface signaling Iga and IgB
Mature B cells
(also produce a δ heavy chain by alternative mRNA splicing
Have IgM and IgD
Where does development of immature B cells take place?
Bone marrow
