Serum of lipopolysacharide-treated mice contains two types of colony-stimulating factor, separable by affinity chromatography
✍ Scribed by F. G. Staber; A. W. Burgess
- Publisher
- John Wiley and Sons
- Year
- 1980
- Tongue
- English
- Weight
- 756 KB
- Volume
- 102
- Category
- Article
- ISSN
- 0021-9541
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✦ Synopsis
Abstract
Serum from mice traated with bacterial lipopolysaccharide (LPS) was fractionated by Con A‐Sepharose affinity chromatography, and assayed in vitro for colony‐stimulating factor (CSF) using mouse bone marrow cells. The CSF failing to bind to concanavalin A‐Sepharose (pool A) had similar biological properties to the unfractionated serum, i.e., it stimulated the formation of about equal numbers of granulocytic, mixed granulocyte‐macrophage and macrophage colonies. The fraction eluted from the Con A‐Sepharose column with α‐methyl‐D‐glucopyranoside (pool B) had a steeper dose‐response curve than either the unfractionated serum or the pool A CSF and most of the colonies were composed of macrophages. A mixture of the pool A and pool B CSFs stimulated colonies in a similar way as unfractionated serum and pool A. The apparent molecular weights of the two types of CSF were determined by two different gel‐filtration procedures. Sephacryl S‐200 gel‐filtration suggested an apparent molecular weight of 85,000 for pool A CSF and 180,000 for pool B CSF. Gel‐filtration on Sepharose CL‐6B in the presence of guanidine hydrochloride (6M) yielded an apparent molecular weight of approximately 23,000 for pool A CSF and 33,000 for pool B CSF. The colony‐forming cells (CFC) responding to pool B CSF were found to have a relatively high sedimentation velocity (peak sedimentation velocity 5.6–6.2 mm/hr) compared to the CFC responding to mouse‐lung conditioned medium (MLCM) whose peak sedimentation velocity was between 4.0–4.5 mm/hour. The CFC responding to pool A CSF had an intermediate sedimentation velocity (peak 4.6–5.2 mm/hour). A time‐course analysis of the morphology of clones or colonies in cultures stimulated with either MLCM or pool B CSF showed that the proporation of different colony types depends significantly on the incubation period and suggested that pool B CSF induced an early commitment of CFC towards macrophage differentiation.