Inhibition of airway inflammation and HIV entry by NNY-CCL14 treatment: Role of CCR1 and CCR5

RATIONALE: Modulation of leukocyte recruitment through intervention with chemokine receptors is an attractive therapeutic strategy. METHODS: Efficacy and potency of NNY-CCL14, its ability to desensitize and internalize CCR1 and CCR5 on B300.19+-cell lines, human and murine leukocytes was studied by calcium release assay and flow cytometry. Airway hyper-responsiveness was measured by head-out plethysmography in NNY-CCL14-treated ovalbumin (OVA)-challenged Balb/c mice. Bronchoalveolar lavage analysis was performed on cytospins. RESULTS: NNY-CCL14 is a potent agonist on B300.19-hCCR1+ (EC50=16.4 nM), B300.19-hCCR5+ (EC50=1.7 nM) and PBMCs (EC50=3.5 nM), also activating murine CCR1 and CCR5. NNY-CCL14 completely desensitizes CCR1- and CCR5-mediated calcium release to further stimulation and effectively internalizes these receptors from cellular surface. NNY-CCL14 also potently inhibits (IC50 = 10.1 nM) CCR5 mediated HIV-1 infection. NNY-CCL14 treatment of OVA-sensitized BALB/c mice reduced influx of eosinophils (p = 0.021) and lymphocytes (p < 0.001) to bronchoalveolar lavage in association with improved airway hyperresponsiveness (p = 0.016). Above all, systemic treatment with NNY-CCL14 down-modulates CCR5 from the surface of lymphocytes. The rapid down-modulation is followed by a gradual CCR5 re-expression over 3 hours. Although, NNY-CCL14 internalizes CCR5 on murine lymphocytes, it does not internalize CCR3 on mouse eosinophils, showing species selectivity regarding this particular receptor. CONCLUSIONS: NNY-CCL14 is an agonist of CCR1 and CCR5 with inhibiting capacity. The inhibitory effects of NNY-CCL14 in the murine model of allergic airway inflammation can be assigned to its interaction with CCR5 and probably CCR1, but independent of CCR3. In summary, NNY-CCL14 is an interesting tool to prevent allergic and infectious diseases. Funding: DFG