Haemopoietic progenitors in the adult mouse omentum: permanent production of B lymphocytes and monocytes.

The coelome-associated lympho-myeloid tissues, including the omentum, are derived from early embryo haemopoietic tissue of the splanchnopleura, and produce B lymphocytes and macrophages. They are reactive in pathologies involving coelomic cavities, in which they can expand in situ the cells of inflammatory infiltrates. We have addressed the question of the role of the adult omentum in permanent basal production of early lymphopoietic progenitors (pro-B/pre-B cells), through characterisation of omentum cells ex vivo, and study of their in vitro differentiation.

Myelopoiesis in the omentum of normal mice and during abdominal inflammatory processes.

Coelomic cavities are relatively isolated from the systemic circulation of blood cells. Resident cell populations have a proper phenotype and kinetics, maintaining their steady-state populations and their responsiveness to local inflammatory reactions, in which the number and quality of coelomic cells can be greatly increased and modified. We have addressed the question of whether the increase in cell infiltrate in the inflamed abdominal cavity is sustained by the proliferation of myeloid cells in the omentum, and if so what are the characteristics of the progenitor cells involved and how the omentum controls their proliferation and differentiation.