n-Nonanoyl-CCL14 (NNY-CCL14), a novel inhibitor of allergic airway inflammation is a partial agonist of human CCR2.
BACKGROUND
Modulation of leukocyte recruitment through blocking of chemokine receptors has been proposed as an attractive therapeutic strategy. We have previously demonstrated that n-Nonanoyl-CC chemokine ligand 14 (NNY-CCL14), a modified analog of the naturally occurring chemokine CCL14(9-74) internalizes and desensitizes human CCR3 resulting in the inactivation of eosinophils. However, inhibitory effects of NNY-CCL14 in murine models of allergic airway inflammation are assigned to its interaction with CCR1 and CCR5.


OBJECTIVE
As CCL2 and its receptor CCR2 have been shown to play important roles in the development of Th2 inflammation, we further evaluated the effects of NNY-CCL14 treatment on CCL2-mediated activation of CCR2.


METHODS
Effects of NNY-CCL14 treatment were studied on cell lines transfected with human CCR2 and primary leukocytes. Functional effects were assessed by calcium efflux assays, flow cytometry and chemotaxis.


RESULTS
Prestimulation with NNY-CCL14 desensitized CCR2-mediated responses to further stimulation with its selective ligand CCL2. No significant internalization of CCR2 was observed when the cells were stimulated with NNY-CCL14, even at concentrations eliciting maximal [Ca(2+)]i mobilization. Above all, NNY-CCL14 pretreatment blocked CCL2-induced chemotaxis of monocytes.


CONCLUSIONS
This study demonstrates that NNY-CCL14 is a partial agonist of CCR2, inhibiting responses of monocytes to the CCR2-selective ligand CCL2. NNY-CCL14 attenuates CCR2-mediated responses by rapidly desensitizing the receptor and preventing chemotaxis, although it is able to induce calcium mobilization but does not lead to CCR2 internalization. Hence this study provides further insights into the possible mechanisms of action of NNY-CCL14, which interacts with multiple chemokine receptors inhibiting the migration and activation of different cell populations involved, thus acting as a potential therapeutic compound to alleviate allergic inflammation.
Gupta
S
S
Clinic of Immunology and Rheumatology, Hannover Medical School, Germany.
Erdmann
G
G
Schulz-Maronde
S
S
Escher
S E
SE
Richter
R
R
Forssmann
W G
WG
Elsner
J
J
Forssmann
U
U
D000818:Animals; D018926:Anti-Allergic Agents / Q000737:chemistry / Q000378:metabolism* / Q000627:therapeutic use; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D002460:Cell Line; D002464:Cell Migration Inhibition / Q000187:drug effects; D002478:Cells, Cultured; D054413:Chemokine CCL11 / Q000737:chemistry / Q000502:physiology / Q000627:therapeutic use*; D019742:Chemokines, CC / Q000737:chemistry / Q000502:physiology / Q000627:therapeutic use*; D006801:Humans; D018836:Inflammation Mediators / Q000502:physiology / Q000627:therapeutic use*; D051379:Mice; D054390:Receptors, CCR2 / Q000819:agonists* / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D012130:Respiratory Hypersensitivity / Q000188:drug therapy* / Q000473:pathology
D018926:Anti-Allergic Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; C519278:CC chemokine ligand 11, N-nonanoyl(1)-; C097720:CCL14 protein, human; C515334:CCR2 protein, human; D054413:Chemokine CCL11; D019742:Chemokines, CC; D018836:Inflammation Mediators; D054390:Receptors, CCR2