Identification of a blood-derived chemoattractant for neutrophils and lymphocytes as a novel CC chemokine, Regakine-1.
Chemokines constitute a large family of chemotactic cytokines that selectively attract different blood cell types. Although most inflammatory chemoattractants are only induced and released in the circulation during acute infection, a restricted number of CXC and CC chemokines are constitutively present in normal plasma at high concentrations. Here, such a chemotactic protein was purified to homogeneity from serum and fully identified as a novel CC chemokine by mass spectrometry and amino acid sequence analysis. The protein, tentatively designated Regakine-1, shows less than 50% sequence identity with any known chemokine. This novel CC chemokine chemoattracts both neutrophils and lymphocytes but not monocytes or eosinophils. Its modest chemotactic potency but high blood concentration is similar to that of other chemokines present in the circulation, such as hemofiltrate CC chemokine-1, platelet factor-4, and beta-thromboglobulin. Regakine-1 did not induce neutrophil chemokinesis. However, it synergized with the CXC chemokines interleukin-8 and granulocyte chemotactic protein-2, and the CC chemokine monocyte chemotactic protein-3, resulting in an at least a 2-fold increase of the neutrophil and lymphocyte chemotactic response, respectively. The biologic effects of homogeneous natural Regakine-1 were confirmed with chemically synthesized chemokine. Like other plasma chemokines, it is expected that Regakine-1 plays a unique role in the circulation during normal or pathologic conditions.
Struyf
S
S
Laboratory of Molecular Immunology, Rega Institute for Medical Research, University of Leuven, Belgium.
Proost
P
P
Lenaerts
J P
JP
Stoops
G
G
Wuyts
A
A
Van Damme
J
J
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D054410:Chemokine CCL7; D054427:Chemokine CXCL6; D018925:Chemokines / Q000737:chemistry; D019742:Chemokines, CC / Q000097:blood / Q000302:isolation & purification* / Q000494:pharmacology; D019743:Chemokines, CXC / Q000494:pharmacology; D002633:Chemotaxis / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid; D016207:Cytokines; D004357:Drug Synergism; D004591:Electrophoresis, Polyacrylamide Gel; D004804:Eosinophils / Q000187:drug effects; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D016209:Interleukin-8 / Q000494:pharmacology; D008214:Lymphocytes / Q000187:drug effects*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D018945:Monocyte Chemoattractant Proteins / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects*; D009994:Osmolar Concentration; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
C515450:CCL7 protein, human; C515503:CXCL6 protein, human; D054410:Chemokine CCL7; D054427:Chemokine CXCL6; D018925:Chemokines; D019742:Chemokines, CC; D019743:Chemokines, CXC; D016207:Cytokines; D016209:Interleukin-8; D018945:Monocyte Chemoattractant Proteins; C426232:regakine 1