High resolution

Module 8: Figure B-cell differentiation

Differentiation of B-cells.

The haematopoietic stem cell (HSC) progenitors, which are formed within the bone marrow, are the precursors that differentiate into mature B-cells through a series of discrete steps that take place in different locations. The initial conversion of HSC progenitors to immature B-cells occurs in the bone marrow. The transitional B-cells leave the bone marrow and make their way to the germinal centres within the lymph nodes where differentiation to mature B-cells takes place. Passage through each step is carefully orchestrated by a signalling system that is based on the Igα and Igβ subunits, and gradually evolves by the addition of other signalling components to form the B-cell receptor (BCR) as part of the differentiation process. The time lines at the bottom illustrate the points where different components appear. See the text for further details.