A lipid chemotactic factor from anaerobic coryneform bacteria including Corynebacterium parvum with activity for macrophages and monocytes

Abstract

A lipid with chemoattractant (chemotactic) activity for mouse and guinea-pig macrophages and for human blood monocytes is released by anaerobic coryneform bacteria (including Corynebacterium parvum). The active lipid is associated with fibrillar structures which lie on the outside of the bacterial cell and are released spontaneously during growth. The lipid can also be extracted easily by a number of methods. The fibrils are loosely associated with a capsule-like structure composed largely of polysaccharide. Purification of the active lipid was achieved by chloroform-methanol extraction of the whole organisms yielding a chloroform-soluble fraction attracting mononuclear phagocytes at concentrations around 10 microgram/ml. The infra-red spectrum of this material showed lipid but no peptide or sugar. Thin-layer chromatography yielded twelve spots of which three had chemoattractant properties. The most active of these gave staining reactions consistent with the presence of phospholipid, the other two probably contained free fatty acids and triglycerides. Thin-layer electrophoresis also yielded an active phosphorus-containing spot. Saturated fatty acids of chain lengths found in the anaerobic coryne forms had weak monocyte-attractant activity. As the active material was progressively purified, its activity as a monocyte attractant weakened.