B-Cell Development and Activation Flashcards
How do B-Cells recognize antigens?
They recognize the shape of the epitope on the antigens.
Where do b-cells develop in fetal development? What kind of b-cells?
in Yolk sac and Fetal liver. Creates B-1 cells
What kind of selection do b-cells undergo? What happens?
They go negative selection where they are tested for self-antigen recognition. If they recognize self, they are destroyed.
What eventually give rise to B-cells?
Common Lymphoid Precursor cells.
What Ig class is usually bound to immature b-cells? which do mature b-cells have?
Immature=IgM.
Mature=have more IgD, and some IgM.
What are the 3 outcomes if b-cells react to self?
- Colonal Deletion=self destruction
- Receptor editing=recombinate genome to try again.
- Anergy=permanently switched off.
What are B-1 cell characteristics? B-2?
B-1: Restricted diversity, no memory, reacts to carbohydrates only
B-2: Memory and specificity, carbs and protein recognition, Use T-cells
What are Marginal B cells?
Cells that are located in the spleen and are specialized for blood bourne pathogens.
Light chains in BCRs are made up of what gene regions? heavy chains?
Light=V,J,C
Heavy=V,D,J,C
What results in a functional Ig variable region? Using what proteins?
recombination of V,D,J regions in heavy chains. Uses RAG proteins.
What does somatic hypermutation do?
Helps fine tune immune response by point mutation in the variable regions of antibody.
What is class switch mutation and how does it work?
mutations that switch Ig classes by breakage and recombination of gene with loss of intervening sequences.
