Final answer:
The 4 outcomes of central tolerance in the selection of immature B cells are anergy, apoptosis, migration, and receptor editing. These mechanisms prevent autoimmune reactions by ensuring B cells do not target the body's own tissues.
Step-by-step explanation:
The 4 outcomes of central tolerance in the selection of immature B cells are as follows: (b) Anergy, apoptosis, migration, and receptor editing. Central tolerance is a mechanism that ensures self-tolerance and prevents autoimmune responses by inactivating or destroying B cells that recognize self-antigens within the bone marrow. The key processes involved are:
- Clonal deletion - Immature B cells that bind strongly to self-antigens are induced to undergo apoptosis, thus being removed from the population.
- Receptor editing - B cells with self-reactive receptors can alter their receptors through additional gene rearrangement, potentially allowing them to avoid recognition of self-antigens.
- Anergy - Some B cells that encounter soluble self-antigen become unresponsive or anergic, leaving them functionally inert.
- Migration - Following the central tolerance mechanisms, surviving immature B cells migrate from the bone marrow to the spleen where they complete their maturation into naïve mature B cells.
This critical process of central tolerance selections ensures that the emerging B cells are capable of recognizing foreign antigens while avoiding harmful reactions against the body's own tissues.