Chapter 6

B cell development in the bone marrow

• B cells start to develop at birth, continues for rest of life

• Pluripotent hematopoietic stem cells give rise to common lymphoid progenitor cells

• Early Pro-B cell

• Late Pro-B cell

• Large Pre-B cell

• Small Pre-B cell

• Immature B-cell

Selection and further development of B cells

• as many as 75% of immature B cells have some affinity for self antigen

• let them interact with bone marrow cells

• if interact with self antigens, get stuck in bone marrow jail

• recetpor editing is rehab for self reacting B cells in bone marrow jail

  • only change light chain

  • try again

  • unsuccessful → apoptosis

• immagure B cells specific for monovalent self antigens are made nonresponsive to antiven

  • no rehab

  • makes B cell anergic

  • anergic B cells enter circulation and then die

• 3 fates for self reactive (Tolerance)

  • survive through receptor editing (central)

  • apoptosis

  • anergic (peripheral)