Purification of a human monocyte-derived neutrophil chemotactic factor that has peptide sequence similarity to other host defense cytokines.
Stimulated human monocytes release several proteins thought to play a role in inflammation, including interleukin 1, tumor necrosis factor, and plasminogen activator. We have purified another proinflammatory protein that is chemotactic for human neutrophils from conditioned medium of lipopolysaccharide-stimulated monocytes. After a series of steps that included anion-exchange chromatography, gel filtration, and HPLC on cation-exchange and reverse-phase columns, an apparently pure protein was obtained that migrated as a single 7-kDa band on NaDodSO4/polyacrylamide gels under reducing or nonreducing conditions. The amino acid composition of this monocyte-derived neutrophil chemotactic factor was different from that of interleukin 1 and tumor necrosis factor. N-terminal amino acid sequence of the first 42 residues was determined. This portion of the molecule has up to 56% sequence similarity with several proteins that may be involved in host responses to infection or tissue injury. It is identical to a portion of a sequence deduced from an mRNA induced by staphylococcal enterotoxin treatment of human leukocytes. At the optimal concentration of 10 nM, 50% of neutrophils added to chemotaxis assay wells migrated toward the pure attractant. Potency and efficacy are comparable to that of fMet-Leu-Phe, which is often used as a reference. In contrast to many attractants, the protein was not chemotactic for human monocytes.
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D001688:Biological Products / Q000302:isolation & purification*; D002630:Chemotactic Factors / Q000302:isolation & purification*; D002634:Chemotaxis, Leukocyte; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007249:Inflammation / Q000503:physiopathology; D008262:Macrophage Activation; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009000:Monocytes / Q000032:analysis*; D015846:Monokines; D009504:Neutrophils / Q000502:physiology*
D000596:Amino Acids; D001688:Biological Products; D002630:Chemotactic Factors; D015846:Monokines