Effects of hematopoietin-1 and interleukin 1 activities on early hematopoietic cells of the bone marrow

Abstract

Hematopoietin-1 (H-1) was purified from the human cell line 5637 and two amino acid sequences were observed in the preparation. One sequence was identical to that of interleukin 1a (IL 1a) and the other to that of IL 1ß. The action of recombinant IL 1a and other hematopoietic growth factors was studied using (a) a high proliferative potential colony-forming cell assay that uses primitive hematopoietic precursors from bone marrow, and (b) a spleen colony-forming unit assay. The results indicate that the IL 1a target cell population is different than the target cell populations of IL 3, granulocyte-macrophage colony-stimulating factor, and granulocyte colony-stimulating factor; that IL 1a in combination with mononuclear phagocyte colony-stimulating factor provides a proliferative stimulus; and that IL 1a has at least a survival-enhancing and possibly proliferation-inducing effect on primitive hematopoietic stem cells.