Homeostatic niche specification among naive and activated B cells: A growing role for the BLyS family of receptors and ligands

B lymphocyte homeostasis encompasses the establishment and maintenance of independently regulated niches, within which cells compete for viability promoting resources. The BLyS/BLyS receptor family controls the size and composition of these niches, by governing the selection and survival of most peripheral B cells. Moreover, different receptor-ligand sets from this family dominate the regulation of various B cell subsets. These observations suggest a model whereby the regulation of BLyS receptors by differentiative and stimulatory cues yield characteristic BLyS receptor signatures, thus specifying homeostatic niche and competitive advantage. (c) 2005 Elsevier Ltd. All rights reserved.