title: Immature mouse granulocytic myeloid cells are characterized by production of ficolin-B.
abstract: Ficolins activate the lectin pathway of the complement system upon binding to carbohydrate patterns on pathogens. To characterize the producer cells of ficolin-B the expression of mouse ficolin-B, the orthologue of human M-ficolin, was studied in macrophages and dendritic cells during differentiation from bone marrow cells, in primary granulocytes, and during differentiation of granulocytes derived from ER-Hoxb8 cells. Expression of ficolin-B mRNA declined in all myeloid cell types to low levels during terminal differentiation. However, in contrast to macrophages and dendritic cells, ficolin-B expression was enhanced upon activation in granulocytes. High expression of ficolin-B was observed in primary immature neutrophilic CD11b(+) Ly-6C(int) Ly-6G(high) granulocytes when isolated from the bone marrow, in particular during sepsis. Ficolin-B was demonstrated in lysates of primary granulocytes, ER-Hoxb8-derived granulocytes, bone marrow-derived macrophages, and dendritic cells. Native ficolin-B from cell lysates and supernatants of granulocytes activated the lectin pathway as measured by binding to MASP-2 and inducing C4 deposition. Specific staining demonstrated intra-cellular or cell associated ficolin-B protein in activated immature granulocytes deposited in a granular fashion. This study shows that ficolin-B is stored in and set free from immature granulocytic myeloid cells indicating a role in the early infection-induced cellular response of these inflammatory cells.
authors.affiliation: Institute of Immunology, University of Regensburg, Regensburg, Germany.
authors.forename: Dorothea
authors.initials: D
authors.lastname: Weber-Steffens
authors.forename: Katja
authors.initials: K
authors.lastname: Hunold
authors.forename: Johanna
authors.initials: J
authors.lastname: Kürschner
authors.forename: Sonia Giraldez
authors.initials: SG
authors.lastname: Martinez
authors.forename: Preetham
authors.initials: P
authors.lastname: Elumalai
authors.forename: Dominic
authors.initials: D
authors.lastname: Schmidt
authors.forename: Analia
authors.initials: A
authors.lastname: Trevani
authors.forename: Valeria L
authors.initials: VL
authors.lastname: Runza
authors.forename: Daniela N
authors.initials: DN
authors.lastname: Männel
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism; D002460:Cell Line; D003167:Complement Activation; D003713:Dendritic Cells / Q000166:cytology / Q000378:metabolism; D004967:Estrogens / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D006098:Granulocytes / Q000166:cytology / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D037102:Lectins / Q000235:genetics / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology / Q000378:metabolism; D050606:Mannose-Binding Protein-Associated Serine Proteases / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D022423:Myeloid Cells / Q000166:cytology / Q000378:metabolism*; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism*; D011485:Protein Binding; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000097604:Ficolins
chemical_list: D004967:Estrogens; D018398:Homeodomain Proteins; D037102:Lectins; D008070:Lipopolysaccharides; D050606:Mannose-Binding Protein-Associated Serine Proteases; D000097604:Ficolins; C095822:Hoxb8 protein, mouse; C491340:MASP-2 protein, mouse
keywords: BMDC; BMDM; CLP; Complement activation; FcnB; GlcNAc; GlcNAc-BSA; Inflammatory cells; Lectin pathway; MASP; MBL; MBL-associated serine protease; MDSC; N-acetyl glucosamine; N-acetyl glucosamine-coupled BSA; NET; PEC; PMN; bone marrow-derived dendritic cells; bone marrow-derived macrophages; cecal ligation and puncture; ficolin-B; mannan-binding lectin; myeloid cell-derived suppressor cells; neutrophil extracellular trap; peritoneal exudate cells; polymorphonuclear neutrophils