Molecular analysis of the membrane insertion domain of proteinase 3, the Wegenerˈs autoantigen, in RBL cells: implication for its pathogenic activity

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

关键词: neutrophil;    autoimmunity;    vasculitis;    leukemia;    inflammation;   

DOI  :  10.1189/jlb.1210695

学科分类：生理学

来源: Federation of American Societies for Experimental Biology

【 摘 要 】

PR3,alsocalledmyeloblastin,isaneutrophilserineproteasethatpromotesmyeloidcellproliferationbycleavingthecyclin‐dependentkinaseinhibitorp21cip1/waf1.Inaddition,itisthetargetofANCAinGPA,anecrotizingvasculitis.Anti‐PR3ANCAbindingtomembrane‐expressedPR3triggersneutrophilactivation,potentiatingvascularinflammation.ThisstudyperformedinRBLcellsidentifiesthestructuralmotifsofPR3membraneanchorageandexaminesitsimpactonPR3proinflammatoryandproliferativefunctions.WiththeuseofMDsimulationsandmutagenesis,wedemonstratethatthemutationsoffourhydrophobic(F180,F181,L228,F229)orfourbasic(R193,R194,K195,R227)aminoacidsabrogatedPR3membraneanchorage.Thehydrophobicpatch‐deficientPR3mutant(PR34H4A)wasstillabletocleavethesyntheticsubstrateBoc‐Ala‐Pro‐Valincelllysates.However,incontrasttoWTPR3,PR34H4Awasnotexpressedattheplasmamembraneafterdegranulationandfailedtocleaveextracellularfibronectin,wasnotexternalizedafterapoptosisanddidnotimpairmacrophagephagocytosisofapoptoticcells,didnotpromotemyeloidcellproliferationandfailedtocleavep21/waf1.PR3membraneinsertionappearstobepivotalforitsproinflammatoryactivities,suchasextracellularproteolysisandimpairmentofapoptoticcellclearance,butalsoformyeloidcellproliferation.Targetingmembrane‐associatedPR3mightconstituteanovel,anti‐inflammatorytherapeuticstrategyininflammatorydiseaseespeciallyinvasculitis,butthisapproachhastobevalidatedinmatureneutrophils...

【 授权许可】

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