Effects of Recombinant Human Tumor Necrosis Factor a, Recombinant Human γ-Interferon, and Prostaglandin E on Colony Formation of Human Hematopoietic Progenitor Cells Stimulated by Natural Human Pluripotent Colony-stimulating Factor, Pluripoietin a, and Recombinant Erythropoietin in Serum-free Cultures

The influences of pure human pluripotent colony-stimulating factor, highly purified pluripoietin a, pure recombinant human tumor necrosis factor a, pure recombinant human 7-interferon, and natural prostaglandin E 1 (PGE 1 ) were evaluated on colony formation of multipotential and erythroid progenitor cells in the presence of recombinant erythropoietin and hemin and on colony formation of granulocyte-macrophage progenitors in normal human marrow cultured in the presence or absence of serum. Serum was replaced by bovine serum albumin, iron-saturated transferrin, cholesterol, and calcium chloride. Increasing concentrations of pluripotent colony-stimulating factor and pluripoietin a stimulated increasing numbers of colonies from nonadherent low-density T-lymphocyte-depleted cells in the absence and presence of serum. Growth was usually greater in the presence of serum and on a unit basis pluripoietin a was more active than pluripotent colony-stimulating factor. Recombinant human tumor necrosis factor a and recombinant human 7-interferon suppressed colony formation colony forming unit-granulocyte-macrophage, burst forming unit-erythroid, and colony forming unit-granulocyteerythroid-macrophage-megakaryocyte; PGE 1 suppressed colony formation by colony-forming unit-granulocyte-macrophage, stimulated colony formation by burst forming unit-erythroid, and had no effects on colony formation by colony forming unit-granulocyte-erythroid-macrophage-megakaryocyte in both serum-containing and serum-free medium. The PGE 1 enhancing effects on erythroid colony formation required T-lymphocytes. Thus, results are similar using serum-containing and serum-free cultures of human bone marrow cells and serum-free defined culture medium can be used to study the mechanisms of action of purified natural and recombinant growth and suppressor molecules in vitro.