Tethering of Ficolin‐1 to cell surfaces through recognition of sialic acid by the fibrinogen‐like domain

Journal of Leukocyte Biology: An Official Publication of the Reticuloendothelial Society

关键词: complement;    innate immunity;    lectin pathway;    MBL/ficolin‐;    associated serine protease;    mannose‐;    binding lectin;    FCN1;    FCN2;    ligand;   

DOI  :  10.1189/jlb.1209802

学科分类：生理学

来源: Federation of American Societies for Experimental Biology

【 摘 要 】

ThreeFicolinshavebeenidentifiedinhumans:Ficolin‐1(M‐Ficolin),Ficolin‐2(L‐Ficolin),andFicolin‐3(H‐Ficolin).Ficolin‐1istheleast‐describedoftheFicolinsandisexpressedbymonocytes,granulocytes,andinthelungs.Ficolin‐1isfoundcirculatingatlowconcentrationsinserumbutisregardedprimarilyasasecretorymoleculethatexertsitsfunctionlocallyininflamedtissues.Ficolin‐1hasbeenreportedonthesurfaceofmonocytesandgranulocytesandwassuggestedoriginallytofunctionasaphagocyticreceptor.However,themoleculedoesnotcontainanyobvioustransmembranedomain,andnobindingpartnershavebeenidentified.TogainfurtherinsightinthephysiologicalroleofFicolin‐1,wesoughttoidentifythemolecularmechanismresponsibleforthemembraneassociationofFicolin‐1tomonocytesandgranulocytes.WedemonstratethatexpressionofFicolin‐1onthecellsurfaceisrestrictedtomonocytesandgranulocytes.Ficolin‐1istetheredtothecellsurfaceofthesecellsthroughitsfibrinogen‐likedomain,andtheligandinvolvedinthebindingofFicolin‐1isshowntobesialicacid.Moreover,rFicolin‐1boundactivatedbutnotrestingTlymphocytes.Together,theseresultsdemonstrateanovelself‐recognitionmechanismofleukocytesmediatedbythefibrinogen‐likedomainofFicolin‐1...

【 授权许可】

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