{"doi":"10.4049/jimmunol.175.5.3150","title":"Human M-Ficolin Is a Secretory Protein That Activates the Lectin Complement Pathway","abstract":"<jats:title>Abstract</jats:title>\n               <jats:p>Three types of ficolins have been identified in humans: L-ficolin, M-ficolin, and H-ficolin. Similar to mannose-binding lectin, L-ficolin and H-ficolin are the recognition molecules in the lectin complement pathway. Another human ficolin, M-ficolin, is a nonserum ficolin that is expressed in leukocytes and lung; however, little is known about its physiologic roles. In this study, we report the characterization of M-ficolin in terms of its protein localization and lectin activity. M-ficolin was localized in secretory granules in the cytoplasm of neutrophils, monocytes, and type II alveolar epithelial cells in lung. M-ficolin precipitated with mannose-binding lectin-associated serine proteases (MASP)-1 and MASP-2 in a coimmunoprecipitation assay, indicating that M-ficolin forms complexes with MASP-1 and MASP-2. M-ficolin-MASP complexes activated complement on N-acetylglucosamine (GlcNAc)-coated microplates in a C4 deposition assay. M-ficolin bound to several neoglycoproteins bearing GlcNAc, N-acetylgalactosamine, and sialyl-N-acetyllactosamine, suggesting that M-ficolin can recognize the common carbohydrate residues found in microbes. Indeed, M-ficolin bound to Staphylococcus aureus through GlcNAc. These results indicate that M-ficolin, like its family members, functions as a recognition molecule of the lectin complement pathway and plays an important role in innate immunity.</jats:p>","journal":"The Journal of Immunology","year":2005,"id":20486,"datarank":10.843669291951787,"base_score":5.5134287461649825,"endowment":5.5134287461649825,"self_citation_contribution":0.8270143119247475,"citation_network_contribution":10.01665498002704,"self_endowment_contribution":0.8270143119247475,"citer_contribution":10.01665498002704,"corpus_percentile":null,"corpus_rank":null,"citation_count":247,"citer_count":200,"citers_with_citation_signal":190,"citers_with_endowment":190,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":123106,"name":"Yuichi Endo","orcid":null,"position":1,"is_corresponding":false},{"id":123116,"name":"Daisuke Iwaki","orcid":null,"position":2,"is_corresponding":false},{"id":123843,"name":"Munehiro Nakata","orcid":null,"position":3,"is_corresponding":false},{"id":122927,"name":"Misao Matsushita","orcid":null,"position":4,"is_corresponding":false},{"id":135207,"name":"Ikuo Wada","orcid":null,"position":5,"is_corresponding":false},{"id":135209,"name":"Keiichi Inoue","orcid":null,"position":6,"is_corresponding":false},{"id":135210,"name":"Mitsuru Munakata","orcid":null,"position":7,"is_corresponding":false},{"id":122928,"name":"Teizo Fujita","orcid":null,"position":8,"is_corresponding":false},{"id":57694,"name":"Yu Liu","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"base_score":5.5134287461649825,"endowment":5.5134287461649825,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"16116205","pmcid":null,"openalex_id":"https://openalex.org/W2100596063","authors":[],"funders":[],"total_grants":0,"fwci":4.6597,"citation_percentile":0.95721746,"influential_citations":0,"citation_trend":[{"year":2012,"count":19},{"year":2013,"count":18},{"year":2014,"count":8},{"year":2015,"count":8},{"year":2016,"count":11},{"year":2017,"count":9},{"year":2018,"count":9},{"year":2019,"count":7},{"year":2020,"count":19},{"year":2021,"count":7},{"year":2022,"count":11},{"year":2023,"count":7},{"year":2024,"count":6},{"year":2025,"count":9},{"year":2026,"count":3}],"oa_status":"bronze","license":"https://academic.oup.com/pages/standard-publication-reuse-rights","oa_locations":[{"url":"https://journals.aai.org/jimmunol/article-pdf/175/5/3150/1207314/3150.pdf","host_type":"journal"},{"url":"https://journals.aai.org/jimmunol/article-pdf/175/5/3150/1207314/3150.pdf","host_type":"publisher"},{"url":"https://academic.oup.com/jimmunol/article-pdf/175/5/3150/62622962/3150.pdf","host_type":"publisher"},{"url":"https://doi.org/10.4049/jimmunol.175.5.3150","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/16116205","host_type":"repository"}],"fields_of_study":["Complement system in diseases","Hemoglobinopathies and Related Disorders","Renal Transplantation Outcomes and Treatments","Complement Activation","Glycoconjugates","Humans","Lectins","Mannose-Binding Lectin","Mannose-Binding Protein-Associated Serine Proteases","RNA, Messenger","Serine Endopeptidases","Staphylococcus aureus","Ficolins"],"mesh_terms":["Ficolins","Complement Activation","Glycoconjugates","Humans","RNA, Messenger","Serine Endopeptidases","Staphylococcus aureus","Lectins","Mannose-Binding Lectin","Mannose-Binding Protein-Associated Serine Proteases"],"keywords":["Ficolin","Lectin pathway","Lectin","Mannan-binding lectin","Complement system","MASP1","Proteases","C-type lectin","Complement control protein","Innate immune system","Collectin","Serine","Biochemistry","Biology","Mannose","NOD2","Complement membrane attack complex","Classical complement pathway","Receptor","Immunology","Antibody","Serine protease","Enzyme"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-06-04T18:44:47.514618Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}