Regulation of memory B and plasma cell differentiation

- Original BCR repertoires affect the fate decisions of B cells.
- Plasma cell fate is facilitated by higher affinity in both pre-GC and GC responses.
- High expression of IRF4 is required for plasma cell differentiation.
- Lower affinity GC B cells are preferentially recruited into the memory pool.
- Bach2 is an important factor for memory B cell differentiation from GC B cells.

Memory B cell generation and antibody production result from a differentiation process that begins when the surface BCR on naïve B cells binds an antigen. How the choice between these fates is tempo-spatially regulated is still obscure, but recent advances have reinforced the concept that the combination of B cell-intrinsic heterogeneity and -extrinsic heterogeneity provided by cells such as T cells is a key determinant. As molecular regulators, the transcription factors IRF4 and Bach2, which participate in these fate choices, have been emerging.