Colony stimulating factor augmentation in human placental conditioned medium.

Because of the variability of different placentas to condition culture medium for colony-stimulating factor (CSF), we have attempted to augment CSF elaboration using endotoxin and bacillus Calmette Guerin (BCG) during the incubation period. Of 14 batches of human placental conditioned media (HPCM) prepared from different placentas, six were found to be inactive (no colony formation at concentrations of 5% to 40% vol/vol), five were found to be a weak stimulator of colony formation (producing < 10 colonies/10(5) human marrow cells plated at a HPCM concentration of 30%) and three were found to be active (producing 30 or more colonies/10(5) cells plated at HPCM concentration of 30%). In six cases augmentation of CSF elaboration was attempted using endotoxin or BCG and in all a marked increase in CSF was achieved. The increased colony formation was found to be due to greater increase in neutrophil and macrophage colonies than eosinophil colonies. The method of augmenting CSF elaboration in HPCM could have important implications for producing large quantities of potent and standardized source of CSF for the use in clinical laboratories and for increasing the yield of colony-stimulating factor(s) for further purification.