Module 4 Flashcards
All things B cells
lymphocytes that can differentiate into plasma cells
B cells
How can B cell receptors bind antigens with high affinity?
B cell receptors continue to develop during repeated exposure to an antigen
What happens in the negetive selection step of B cell development?
make sure there’s not self-binding and autoimmunity
What happens in the positive selection step of B cell development?
The good non-self-binding B cells get moved to secondary lymphoid tissues to mature
What are the names of the various cells in B cell stages of development? Starting with Stem Cells
Stem cell, early pro-B cell, late pro-B cell, large pre-B cell, small pre-B cell, immature B cell
What do cell adhesion molecules (CAMs) do?
Connect stemm cells to bone marrow stromal cells
Major cytokine in B cell development in bone marrow
IL-7
What stage of B cell development does D-J rearranging occur?
early pro-B cell
What stage of B cell development does V-DJ rearranging occur?
late pro-B cell
Does heavy chain or light chain rearrangement occur first for B cells?
heavy chain
What happens to a pro-B cell if neither the maternal nor paternal chromosomes give productive rearrangement?
apoptosis
What ensures that B-cell receptors have a single specificity?
allelic exclusion
What results from a productive chromosomal rearrangement?
mu heavy chain
hallmark of a large pre-B cell
functional m chain
VpreB and lambda5 combine to do what?
form a surrogate llight chain to test the quality of the m chain
What stage of B cell development does light chain rearrangement occur?
pre-B cell
Which light chain rearranges first?
Kappa then lambda
Where do light chains assemble with the m chain to form membrane bound IgM?
endoplasmic reticulum
signals for the removal of self-reactive B cells in the bone marrow
negative selection
antigen that contains more than one epitope or more than one copy of the same epitope
multivalent antigen
process of removing self-reactive B cells from the bone marrow
clonal deletion
What happens to immature B cells that bind multivalent self-antigens?
undergo receptor editing to try and make it usable still
Process of inducing rearrangement, apoptosis, or anergy of self-reactive immature B cells
central tolerance
What happens to monovalent self-reactive B cells?
anergy
3 steps of B cell activation signaling
1) binding of the B cell receptor to its specific antigen, 2) crosslinking the receptor, and 3) signaling by the B cell co-receptor
What does crosslinking do in B cell activation?
signals the B cell to change gene expression in the nucleus
Where do B-1 B cells develop?
omentum/peritoneal and pleural cavities
Major immunoglobulin produced by B-1 cells
IgM
What 4 things does thymus-dependent B-cell activation result in?
somatic hypermutation, affinity maturation, isotype switching, and immune memory
what type of cell displays antigens in the primary follicle?
follicular dendritic cells
Which antigens activate B cells through TLR signaling
TI-1 antigens
Which antigens have repeated epitopes on their surface for crosslinking B cell receptors
TI-2 antigens
Which type of B cells don’t need T cell help for activation?
B1 B cells
Which B cells use activation from T helper cells to produce high affinity memory or plasma cells?
B2 b cells
process that allows IgA dimer to acquire a secretory component
transcytosis
What antibody is released in response to parasitic infection?
IgE
Where is dimeric IgA found?
mucosal secretions
This receptor transports IgG from the bloodstream to the tissues
FcRn
This receptor transports IgA across epithelia for transcytosis
PlgR (poly-Ig receptor)
What causes mast cells to release their granules?
cross linking of IgE on the mast cell surfaces
What kinds of infection can be prevented by neutralizing antibodies?
bacterial and viral
Which antibodies neutralize toxins and venom?
IgG and IgA
What about IgM enhances opsonization and helps activate classical complement
the pentameric shape
How many molecules of IgG are needed to activate complement?
two or more
Which receptor on erythrocytes helps clear immune complexes from circulation?
CR1
Which receptor on NK cells recognizes IgG-coated target cells and signals them to die?
Fc Receptor
Good neutralizing antibodies
IgG, IgA
Good opsonizing antibodies
IgG and macrophages/neutrophils
Good complement activating antibodies
IgG and IgM
Antibody that activates mast cells
IgE
Antibody dependent cellular cytotoxicity (ADCC) uses which antibody and which type of cell?
IgG and NK cells
