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Human placental conditioned medium contains monocyte-derived recruiting activity (MRA)
Experimental Hematology
|September 1, 1986
Summary
Human placental conditioned medium contains both monocyte-derived recruiting activity (MRA) and colony-stimulating activity (CSA). These distinct granulopoietic factors can be separated using chromatofocusing based on their different isoelectric points.
Area of Science:
- Hematology
- Cell Biology
- Biochemistry
Background:
- Monocyte-derived recruiting activity (MRA) is known to stimulate endothelial cells.
- Endothelial cells release granulopoietic colony-stimulating factors (CSF).
- Human placental conditioned medium (HPCM) is a common source for in vitro studies of CSA.
Purpose of the Study:
- To determine if HPCM contains both MRA and CSA.
- To investigate if MRA and CSA can be separated based on their isoelectric points.
Main Methods:
- Concentrated HPCM samples were subjected to chromatofocusing.
- Fractions were tested in bioassays for MRA and CSA.
- Isoelectric points were determined by elution pH.
Main Results:
- HPCM was found to contain both MRA and CSA.
- The majority of MRA eluted at pH 7.6–8.2, yielding a 2000-fold purification.
- CSA eluted at pH 5.6 or below, with no detectable CSA in the major MRA peak.
Conclusions:
- HPCM contains heterogeneous granulopoietic activities.
- MRA and CSA possess substantially different isoelectric points.
- Chromatofocusing is an effective single-step method for separating MRA and CSA from HPCM.