9: B Cell Maturation Flashcards
Rearrangement occurs in the ___ of Ag
absence
What is the first antibody produced by B cells?
IgM
Where does activation to a plasma cell, isotype switching, and somatic hypermutation occur?
periphery
Germinal center
specialized areas of secondary lymphoid organs that contain proliferating B cells
Plasma cell migrate to either ___ or ____
circulation or bone marrow/spleen
What must occur before differentiation into plasma cell?
exposure to antigen
When do B cells multiply and start to secrete IgM?
after stimulation from antigen-specific T cells
isotype switching
generates antibodies with different heavy chain regions
somatic hypermutation
creation of antibodies that bind stronger to a given epitope
What enzyme chemically changes DNA bases during somatic hypermutation
activation induced deaminase (AID)
Where does somatic hypermutation occur?
germinal center
Affinity maturation
if the mutation provides better binding of the Ab pocket to Ag
Gene conversion
similar to somatic hypermutation except for short sequences within the exon are replaced rather than a single base
Where does gene conversion occur?
Birds- bursa
Ruminants- Peyer’s Patch
What influences which Ig is favored during isotype switching?
cytokines
