Abstract: The present invention is directed to an autocrine growth factor. In particular, it relates to the production, purification and uses of stem cell proliferation factor (SCPF). In various cell lines, the protein of the invention exists in two forms, a soluble form and a membrane bound form which is detectable on the surface of a small percentage of human bone marrow cells and stimulates the proliferation of these cells. Therefore, SCPF may have a wide range of applications including but not limited to augmenting the growth of hematopoietic stem cells. Further, removal of the protein by an antibody may be useful in controlling tumor cell growth.

Abstract: The invention derives from the discovery of cells, non-adherent (NA) cells, which have properties indicating that they may be pluripotent lymphohematopoietic progenitor cells. These cells, and the stromal cells derived from bone marrow cultures, produce factors which stimulate the growth of primitive cell colonies, as reflected in their stimulation of the growth of colonies of NA cells. These primitive cell colony stimulating factors (PC-CSFs) may be useful in the treatment of disorders which can be alleviated by the proliferation of desired cells. In addition, the NA cells and/or PC-CSF(s) may provide an alternative and/or supplementary method to bone marrow transplantation to alleviate hematopoietic disorders.