title: Eotaxin-3/CCL26 is a natural antagonist for CC chemokine receptors 1 and 5. A human chemokine with a regulatory role.
abstract: Eotaxin-3 (CCL26), like eotaxin (CCL11) and eotaxin-2 (CCL24), has long been considered a specific agonist for CC chemokine receptor 3 (CCR3), attracting and activating eosinophils, basophils, and Th2 type T lymphocytes. Although not characterized extensively yet, its expression profile coincides with a potential role in allergic inflammation. We recently reported that eotaxin-3 is an antagonist for CCR2 (Ogilvie, P., Paoletti, S., Clark-Lewis, I., and Uguccioni, M. (2003) Blood 102, 789-784). In the present report, we provide evidence that eotaxin-3 acts as a natural antagonist on CCR1 and -5 as well. Eotaxin-3 bound to cells transfected with either CCR1 or -5 as well as to monocytes expressing both receptors. Further, it inhibited chemotaxis, the release of free intracellular calcium, and actin polymerization when cells were stimulated with known agonists of CCR1 and -5. An analysis of its three-dimensional structure indicated the presence of two distinct epitopes that may be involved in specific binding to CCR1, -2, -3, and -5. Taken together, our data thus indicate eotaxin-3 to be the first human chemokine that features broadband antagonistic activities, suggesting that it may have a modulatory rather than an inflammatory function. Further, eotaxin-3 may play an unrecognized role in the polarization of cellular recruitment by attracting Th2 lymphocytes as well as eosinophils and basophils via CCR3, while concomitantly blocking the recruitment of Th1 lymphocytes and monocytes via CCR1, -2, and -5.
authors.affiliation: Institute for Research in Biomedicine, CH-6500 Bellinzona, Switzerland.
authors.forename: Vibor
authors.initials: V
authors.lastname: Petkovic
authors.forename: Christian
authors.initials: C
authors.lastname: Moghini
authors.forename: Samantha
authors.initials: S
authors.lastname: Paoletti
authors.forename: Mariagrazia
authors.initials: M
authors.lastname: Uguccioni
authors.forename: Basil
authors.initials: B
authors.lastname: Gerber
mesh_terms: D000595:Amino Acid Sequence; D065100:CCR5 Receptor Antagonists; D000075906:Chemokine CCL26; D019742:Chemokines, CC / Q000378:metabolism*; D002633:Chemotaxis / Q000502:physiology; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D054389:Receptors, CCR1; D019713:Receptors, CCR5 / Q000235:genetics / Q000378:metabolism; D019707:Receptors, Chemokine / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D018418:Th2 Cells / Q000378:metabolism
chemical_list: C120429:CCL26 protein, human; C515300:CCR1 protein, human; D065100:CCR5 Receptor Antagonists; D000075906:Chemokine CCL26; D019742:Chemokines, CC; D054389:Receptors, CCR1; D019713:Receptors, CCR5; D019707:Receptors, Chemokine