The endoplasmic reticulum is a key component of the plasma cell death pathway.

Plasma cells (PC) are the effector cells of the humoral Ab response. Unlike other dedicated secretory cells, they exist as two populations with opposite cell fates: short-lived and long-lived PC. Upon transformation they lead to an incurable neoplasia called multiple myeloma.

The life and death of a B cell.

Regulation of apoptosis in the B cell lineage has implications for homeostasis, quality control of the antibody response, and tolerance. In this chapter we examine the different checkpoints that control life and death decisions of B cells during the antigen-independent and antigen-dependent phases of their development. We discuss the cell death mechanism involved in elimination of unwanted B cells at different stages of their development as well as the signals that trigger or repress the apoptotic process.

BCR ligation reprograms B cells for migration to the T zone and B-cell follicle sequentially.

We have studied the impact of B-cell receptor (BCR) or CD40 ligation on the in vitro chemotactic response of tonsillar B cells to 4 chemokines: stromal cell-derived factor (SDF)-1alpha, macrophage inflammatory protein (MIP)-3alpha, MIP-3beta, and B-cell-attracting chemokine (BCA)-1. In the tonsil, SDF-1 and MIP-3alpha are both expressed in the crypt epithelium, while MIP-3beta is found in the T zone and BCA-1 in the follicles. Resting virgin and memory B cells display a similar chemotaxis pattern, and they both have the potential to migrate in vitro to all 4 chemokines studied.