title: Soluble Siglec-5 associates to PSGL-1 and displays anti-inflammatory activity.
abstract: Interactions between endothelial selectins and the leukocyte counter-receptor PSGL1 mediates leukocyte recruitment to inflammation sites. PSGL1 is highly sialylated, making it a potential ligand for Siglec-5, a leukocyte-receptor that recognizes sialic acid structures. Binding assays using soluble Siglec-5 variants (sSiglec-5/C4BP and sSiglec-5/Fc) revealed a dose- and calcium-dependent binding to PSGL1. Pre-treatment of PSGL1 with sialidase reduced Siglec-5 binding by 79 ± 4%. In confocal immune-fluorescence assays, we observed that 50% of Peripheral Blood Mononuclear Cells (PBMCs) simultaneously express PSGL1 and Siglec-5. Duolink-proximity ligation analysis demonstrated that PSGL1 and Siglec-5 are in close proximity (<40 nm) in 31 ± 4% of PBMCs. In vitro perfusion assays revealed that leukocyte-rolling over E- and P-selectin was inhibited by sSiglec-5/Fc or sSiglec-5/C4BP, while adhesion onto VCAM1 was unaffected. When applied to healthy mice (0.8 mg/kg), sSiglec-5/C4BP significantly reduced the number of rolling leukocytes under basal conditions (10.9 ± 3.7 versus 23.5 ± 9.3 leukocytes/field/min for sSiglec-5/C4BP-treated and control mice, respectively; p = 0.0093). Moreover, leukocyte recruitment was inhibited over a 5-h observation period in an in vivo model of TNFalpha-induced inflammation following injection sSiglec-5/C4BP (0.8 mg/kg). Our data identify PSGL1 as a ligand for Siglec-5, and soluble Siglec-5 variants appear efficient in blocking PSGL1-mediated leukocyte rolling and the inflammatory response in general.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France.
authors.forename: Marion
authors.initials: M
authors.lastname: Pepin
authors.affiliation: Aix Marseille Université, Inserm UMR_S 1076, (VRCM) Vascular Research Center of Marseille, 13385 Marseille, France.
authors.forename: Soraya
authors.initials: S
authors.lastname: Mezouar
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Pegon
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Muczynski
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Adam
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France.
authors.forename: Elsa P
authors.initials: EP
authors.lastname: Bianchini
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France.
authors.forename: Amine
authors.initials: A
authors.lastname: Bazaa
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France.|Department of Biological Hematology, CHU Bicetre, Hopitaux Universitaires Paris Sud, AP-HP, Paris, France.
authors.forename: Valerie
authors.initials: V
authors.lastname: Proulle
authors.affiliation: Institut de Recherche International Servier, Recherche Translationelle et Clinique Oncologie, 92150, Suresnes, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Rupin
authors.affiliation: Institut de Recherches Servier, Unité de Recherche et de Découverte Cardiovasculaire, 92150, Suresnes, France.
authors.forename: Jerome
authors.initials: J
authors.lastname: Paysant
authors.affiliation: Aix Marseille Université, Inserm UMR_S 1076, (VRCM) Vascular Research Center of Marseille, 13385 Marseille, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Panicot-Dubois
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France.
authors.forename: Olivier D
authors.initials: OD
authors.lastname: Christophe
authors.affiliation: Aix Marseille Université, Inserm UMR_S 1076, (VRCM) Vascular Research Center of Marseille, 13385 Marseille, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Dubois
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Lenting
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France.
authors.forename: Cécile V
authors.initials: CV
authors.lastname: Denis
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D015214:Antigens, Differentiation, Myelomonocytic / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D004195:Disease Models, Animal; D019040:E-Selectin / Q000378:metabolism; D005260:Female; D006801:Humans; D007249:Inflammation / Q000139:chemically induced / Q000188:drug therapy / Q000473:pathology*; D037102:Lectins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D036904:Leukocyte Rolling / Q000502:physiology*; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008810:Mice, Inbred C57BL; D019007:P-Selectin / Q000378:metabolism; D054730:Protein Interaction Domains and Motifs; D012995:Solubility; D014409:Tumor Necrosis Factor-alpha / Q000633:toxicity
chemical_list: D000893:Anti-Inflammatory Agents; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D019040:E-Selectin; D037102:Lectins; D008562:Membrane Glycoproteins; D019007:P-Selectin; C084882:P-selectin ligand protein; C546936:SELE protein, human; C114531:SIGLEC5 protein, human; D014409:Tumor Necrosis Factor-alpha