Details for amaxa FAQ article #99

«What is the difference between pro-B cells and pre-B cells?»

The pre vs. pro designation arises from the gene rearrangements that take place on the heavy and light chains of the specific antibodies displayed on the surface of the B cell, which cause the cell to eventually be activated in an antigen-specific fashion.
When the B cell undergoes the V-D-J rearrangement in the heavy chain (H-chain; which occurs before the light chain rearrangements)., the cell is considered a pro-B cell (D-J rearrangement is early pro-B, and V-D-J rearrangement is late pro-B cell), and when the light chain rearranges (L-chain; V-J rearrangement), then the cell is considered a pre-B cell. Also, at this time, the heavy chain appears on the cell surface, so there is an event that is detectable by flow cytometry at the time of the differentiation from pro-B cell into a pre-B cell.