A model of BCR/BLyS interaction of immature B-cells to transitional B-cells. In bone marrow, weak BCR linkage of immature B-cells induces BLyS-receptor expression and a down-expression of RAG-2, an enzyme involved in BCR editing. In addition, immature B-cells can be rescued from the negative selection of the BCR signaling apoptotic pathway. After a functional (but not strong self-reactive) BCR editing is accomplished. In case of high BLyS level, some weak self-reactive B-cells (weak BCR/antigen affinity) can be developed into T-transitional immature B-cell stage.
