The role of the thymus in erythropoiesis

Abstract

The W/Wv mouse model of hypoplastic anemia has proven helpful in discerning the role of regulatory accessory cells that interact with stem cells for hematopoietic stem cell proliferation and differentiation. We have demonstrated a requirement for thymic cells in the reconstitution of W/Wv anemic mice following bone marrow transplantation. Depletion of T cells from the graft by treatment with anti-theta (alpha-Thy 1.2) antibody and complement prevents the engraftment of donor cells. We examined the role of thymocytes in vitro and demonstrated: (a) two regulatory populations; (b) the "enhancing" population was resistant to radiation treatment, alkylating agents, and a blocker (DFMO) of polyamine biosynthesis; and (c) the suppressor population was sensitive to radiation, alkylating agent, and DFMO treatment.