Serum of lipopolysacharide‐treated mice contains two types of colony‐stimulating factor, separable by affinity chromatography

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..