BACH2–BCL6 balance regulates selection at the pre-B cell receptor checkpoint

A Bach2 link between pre-B cell receptor checkpoint and pre-B cell ALL.

Bach2 is a transcription factor required for affinity maturation of B cells. A recent study reveals, quite unexpectedly, that Bach2 also plays a key role in the pre-B cell receptor checkpoint and functions as a tumor suppressor in pre-B cell acute lymphocytic leukemia.

Plugging the leaky pre-B cell receptor.

Selection of individual VH genes occurs at the pro-B to pre-B cell transition.

B cells are subjected to selection at multiple checkpoints during their development. The selection of Ab H chains is difficult to study because of the large diversity of the CDR3. To study the selection of individual Ab H chain V region genes (V(H)), we performed CDR3 spectratyping of ∼ 75-300 rearrangements per individual V(H) in C57BL6/J mice. We measured the fraction of rearrangements that w...

Radiosensitive SCID patients with Artemis gene mutations show a complete B-cell differentiation arrest at the pre-B-cell receptor checkpoint in bone marrow.

Severe combined immunodeficiency disease (SCID) can be immunologically classified by the absence or presence of T, B, and natural killer (NK) cells. About 30% of T(-)B(-)NK(+) SCID patients carry mutations in the recombination activating genes (RAG). Some T(-)B(-)NK(+) SCID patients without RAG gene mutations are sensitive to ionizing radiation, and several of these radiosensitive (RS) SCID pat...

Inducible differentiation and apoptosis of the pre-B cell receptor-positive pre-B cell line.

The function of the pre-B cell receptor (pre-BCR) during B cell differentiation is not precisely defined. To investigate the pre-BCR receptor activity, we have established pre-BCR-positive pre-B cell lines that are able to differentiate into immature B cells in vitro. Antibody cross-linking of the pre-BCR induced apoptosis and differentiation accompanied with tyrosine phosphorylation. A specifi...