title: Effects of human leukocyte conditioned medium on mouse haemopoietic progenitor cells.
abstract: Medium conditioned by human peripheral blood leukocytes (HLCM) was studied for its in vitro effects on haemopoietic progenitor cells (CFU-s and CFU-c) present in mouse bone marrow. HLCM has poor colony stimulating activity in semi-solid cultures of mouse bone marrow cells, but invariably increases the number of colonies obtained in the presence of plateau levels of semi-purified colony stimulating factor (CSF). In liquid cultures, HLCM appears to contain a potent initiator of DNA synthesis in CFU-s, an activity which coincides with an increased CFU-s maintenance and causes a three- to four-fold increase in CFU-c number. It is apparent from this study that HLCM, in addition to stimulating colony formation in cultures of human bone marrow cells, has a profound in vitro effect on primitive haemopoietic progenitor cells of the mouse, which cannot be attributed to CSF.
mesh_terms: D000818:Animals; D002452:Cell Count / Q000187:drug effects; D002478:Cells, Cultured; D003115:Colony-Stimulating Factors / Q000494:pharmacology*; D003470:Culture Media; D004247:DNA / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D006023:Glycoproteins / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007962:Leukocytes / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains
chemical_list: D003115:Colony-Stimulating Factors; D003470:Culture Media; D006023:Glycoproteins; D004247:DNA