Bone Marrow Lymphocytes' Development and Dynamics

Abstract

The bone marrow (BM) is an integral part of the immune system that communicates with other immune tissues via the bloodstream but does not have lymphatic vessels. It is the primary site of lymphopoiesis, where B cells and early T-cell progenitors develop, from late fetal life onwards, and a secondary lymphoid organ for B lymphocytes. At the same time, it regulates the function and dynamics of the immune system in a steady state and disease conditions. Activating and inhibitory signals from various marrow elements regulate the traffic of lymphocyte subtypes (B, T, and NK), including direct cell contact and released factors from stromal cells. This chapter is a review of the life cycle and dynamics of lymphoid cells in health and representative immune-associated disorders. Understanding the central bone marrow’s role may clarify the pathologic changes and open potential therapeutic channels in some disorders.