16 - B Cells Flashcards
Gene segments involved in heavy chain reassortment
V D J
Gene segments involved in light chain reassortment
V J (kappa or lambda)
Enzyme that is involved in minigene recombination
RAG (recombination activation gene)
4 main sources of antibody diversity
1) Junctional diversity
2) Combinatorial diversity
3) V region diversity
4) Somatic hypermutation
Factor that contributes the most to BCR diversity
Junctional diversity
Enzyme that increases junctional diversity
TdT (terminal deoxynucleotide transferase)
Important enzyme in testing of pre-BCR
Bruton’s tyrosine kinase. Involved in signal transduction from binding of pre-BCR to ligand
Important interleukin in lymphocyte development
IL-7 (inhibits lymphocyte apoptosis)
What releases IL-7 in lymphocyte development?
Bone marrow stromal cells
Early pro-B cell
DJ heavy chain rearrangement
Late pro-B cell
V-DJ heavy chain rearrangement
Large pre-B cell
Heavy chain VDJ rearranged.
Complex heavy chain with pseudo light chain to test if functional. BTK necessary for detection of binding.
Small pre-B cell
V-J light chain rearrangement
Immature B cell
IgM expressed on cell surface
Mature B cell
IgM and IgD expressed on cell surface from differential splicing of heavy chain transcripts
Cytokine that can lead to IgA isotype switching
TGF-b
Cytokine that can lead to IgG isotype switching
IFNg
Cytokine that can lead to IgE isotype switching
IL-4
Isotypes best at neutralisation
IgG, IgA
Isotypes best at opsonisation
IgG1>IgG3>IgG4, IgA
Antibody-dependent cell-mediated cytotoxicity
IgG1, IgG3
Antibody isotype best at stimulating degranulation
IgE
Isotype best at C’ activation
IgM>IgG1, IgG3>IgG2, IgA
Cells with FcgRI
Macrophages, neutrophils
Cells with FcgRIIA
Macrophages, neutrophils
FcgRI, FcgRIIA function
Phagocytosis activation
FcgRIIB function
B-cell inhibition
FcgRIIIA cells
NK cells
FcgRIIIA function
NK cell ADCC
FcgRIIIB cells
Neutrophils
FcgRIIIB function
Phagocytosis
FceRI function
Mast cell degranulation
