Activated human mononuclear phagocytes release a substance(s) that induces replication of quiescent human fibroblasts.
Human mononuclear phagocytes (HMP) treated in vitro with N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) released a soluble substance(s) that induced in vitro replication of subconfluent, quiescent, serum-free human fibroblasts. The response was enhanced if nonmitogenic plasma-derived serum (PDS) was added to the HMP-conditioned media after harvest. The capacity of serum-free, quiescent fibroblasts to respond to the HMP-released substance(s) diminished with time in culture. The diminished proliferative response was reversed by adding PDS to the MDP-HMP-conditioned media. Similar results were obtained in parallel experiments using platelet-derived growth factor (PDGF). These data suggest that the HMP-associated growth-promoting substances may, like PDGF, act co-ordinately with substances in PDS to stimulate the proliferation of cells in vitro.
D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000494:pharmacology; D002478:Cells, Cultured; D006133:Growth Substances / Q000378:metabolism*; D006801:Humans; D008214:Lymphocytes / Q000502:physiology; D008934:Mitogens / Q000378:metabolism; D009000:Monocytes / Q000187:drug effects / Q000502:physiology*; D010586:Phagocytes / Q000502:physiology*
D006133:Growth Substances; D008934:Mitogens; D000119:Acetylmuramyl-Alanyl-Isoglutamine