Role of the endothelial surface layer in neutrophil recruitment

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

关键词: cell adhesion;    emigration;    endothelial glycocalyx;    proteoglycans;   

DOI  :  10.1189/jlb.3MR0115-011R

学科分类：生理学

来源: Federation of American Societies for Experimental Biology

【 摘 要 】

Neutrophilrecruitmentinmosttissuesislimitedtopostcapillaryvenules,whereE‐andP‐selectinsareinduciblyexpressedbyvenularendothelialcells.ThesemoleculessupportneutrophilrollingviabindingofPSGL‐1andotherligandsonneutrophils.Selectinsextend≤38nmabovetheendothelialplasmamembrane,andPSGL‐1extendsto50nmabovetheneutrophilplasmamembrane.However,endothelialcellsarecoveredwithanESLcomposedofglycosaminoglycansthatis≥500nmthickandhasmeasurableresistanceagainstcompression.Theneutrophilsurfaceisalsocoveredwithasurfacelayer.Thesesurfacelayerswouldbeexpectedtocompletelyshieldadhesionmolecules;thus,neutrophilsshouldnotbeabletorollandadhere.However,inthecremastermuscleandinmanyothermodelsinvestigatedusingintravitalmicroscopy,neutrophilsclearlyroll,andtheirrollingiseasilyandquicklyinduced.ThisconundrumwasthoughttoberesolvedbytheobservationthattheinductionofselectinsisaccompaniedbyESLshedding;however,ESLsheddingonlypartiallyreducestheESLthickness(to200nm)andthusisinsufficienttoexposeadhesionmolecules.Inadditiontoitsantiadhesivefunctions,theESLalsopresentsneutrophilarrest‐inducingchemokines.ESLheparansulfatecanalsobindL‐selectinexpressedbytheneutrophils,whichcontributestorollingandarrest.WeconcludethatESLhasbothproadhesiveandantiadhesivefunctions.However,mostpreviousstudiesconsideredeitheronlytheproadhesiveoronlytheantiadhesiveeffectsoftheESL.AnintegratedmodelfortheroleoftheESLinneutrophilrolling,arrest,andtransmigrationisneeded...

【 授权许可】

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