Pharmacological profile of a bifunctional ligand of the formyl peptide receptor1 fused to the myc epitope
Authors: | Charest-Morin, Xavier; Roy, Caroline; Fernandes, Maria J.; Marceau, François |
Abstract: | In human peripheral blood neutrophils or in myeloid PLB-985 cells differentiated towards a neutrophil-like phenotype, the peptide N-formyl-L-norleucyl-L-leucyl-L-phenylalanyl-L-norleucyl-L-tyrosyl-L-leucyl-fluorescein isothiocyanate (f-Nle-Leu-Phe-Nle-Tyr-Lys-FITC) binds to and activates formyl peptide receptor1 (FPR1) and is submitted to receptor-mediated endocytosis (microscopy, cytofluorometry). This peptide may be considered a C-terminally extended version of f-Met-Leu-Phe which carries a fluorescent cargo into cells. By analogy to other peptide hormones for which we have evaluated epitope-tagged agonists as carriers of antibody cargoes, we have designed and evaluated f-Nle-Leu-Phe-Nle-Tyr-Lys-myc, C-terminally extended with the 10-residue myc tag. This peptide is as potent as f-Met-Leu-Phe to compete for f-Nle-Leu-Phe-Nle-Tyr-Lys-FITC uptake by PLB-985 cells, but did not mediate (10–1000 nM) the internalization of the fluorescent anti-myc monoclonal antibody 4A6 added to the extracellular fluid at ~ 7 nM (microscopy). The nonfluorescent version of the antibody (28 nM) acts as a pre-receptor antagonist of f-Nle-Leu-Phe-Nle-Tyr-Lys-myc, but not of f-Met-Leu-Phe (superoxide release assay in differentiated PLB-985 cells). A further prolonged analog, f-Nle-Leu-Phe-Nle-Tyr-Lys-(Asn-Gly)5-myc, designed to decrease the possible steric hindrance between FPR1 and the bound anti-myc antibody, has little affinity for the receptor, precluding a direct assessment of this issue. Thus, the relatively low-affinity anti-myc antibody used at a high concentration functionally behaves as a selective pre-receptor antagonist of the agonist f-Nle-Leu-Phe-Nle-Tyr-Lys-myc. |
Document Type: | Article de recherche |
Issue Date: | 10 February 2015 |
Open Access Date: | 20 November 2017 |
Document version: | AM |
Permalink: | http://hdl.handle.net/20.500.11794/15925 |
This document was published in: | International immunopharmacology, Vol. 25 (1), 229–234 (2015) https://doi.org/10.1016/j.intimp.2015.01.029 Elsevier |
Alternative version: | 10.1016/j.intimp.2015.01.029 25681283 |
Collection: | Articles publiés dans des revues avec comité de lecture |
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