B- and T-cell Maturation--Diebel Flashcards
Which receptor causes proliferation of pro-B-cells?
IL-7R
IL-7R uses what intracellular cascade?
STAT5
c-Kit
expressed on pro B-cells
(progenitor B-cells)
X-linked agammaglobulinemia
defect in Bruton’s tyrosine kinase (Btk)
faulty late pro B-cell –> large pre B-cell transition
NOT SCID
B1 cells
Location
Source
Varible Light Region Diversity
Somatic Hypermutation
Isotypes Produced
Response Molecules
Memory Produced
Surface IgD
- periteoneal and pleural cavities
- self-renewing
- low light chain diversity
- no somatic hypermutation
- IgM produced
- responds mostly to carbs
- no memory produced
- no surface IgD
B2 cells
Location
Source
Varible Light Region Diversity
Somatic Hypermutation
Isotypes Produced
Response Molecules
Memory Produced
Surface IgD
- peripheral lymphoid organs
- BM
- high diversity
- somatic hypermutation
- IgG primarily
- responds mostly to proteins
- memory is produced
- surface IgD on naïve cells
How do you (generally) get naïve B-cell activation?
need 2+ responses
either:
-2 surface antibodies bind same antigen (easy becaues many have repeats)
or
-1 antibody binds and complement receptor also binds
requires integration of cascades
TI-1 antigens
bacterial cell wall components
primarily LPS
TI-2 antigens
primarily carbohydrates
ie flagella
What happens when TCR is stimulated but CD28 is absent?
anergy
How do superantigens function?
bind any TCR and MHC complex together
massive T-cell proliferation
cytokine storm
shock
death
What are the stages of B-cell maturation?
stem cell > early pro-B > late pro-B > large pre-B > small pre-B > immature B > mature B > activated B > memory > plasma
When is c-Kit present on B-cells?
stem cell (a lot)
early pro-B (less)
*binds stromal cells in BM*
When is CD34 present on B-cells?
stem cell –> early pro B-cells
When is CD43 present on B-cells?
early –> late pro B-cells
