L-selectin(Leukocyte-EndothelialCellAdhesionMolecule-1)belongstotheselectinfamilyofadhesionmolecules.TogetherwithELAM-1(E-selectin)andGMP-140(P-selectin)L-selectinmediatestheinitialinteractionsofleukocyteswithendothelialcells.Selectinsguidenon-activatedpolymorphonuclearcellstotheareasofinflammationincreatingfirst,loosecontactswiththeendotheliallayer.L-selectininthisaspectmediatesrollingofPMN"sonendothelialcells.ThepotentialbindingpartnersofL-selectincarryanegativecharge,probablyasialicacidand/orsulphate,andmaycontainmannoseandfucose.Inaddition,L-selectinmayalsointeractwithELAM-1whichisexpressedoncytokine-activatedendothelialcells.L-selectinisconstitutivelyexpressedonmostleukocytes(PMN"s,monocytes,lymphocytesubsets)inaseeminglyfunctionalform.Itisrequiredforthebindingoflymphocytestothehighendothelialvenulesofperipherallymphnodes(andthereforeservesasalymphocyterecirculatingreceptor)andfortheinvasionofneutrophilsintositesofinflammation.Whenneutrophilsareactivated,L-selectinisshedbyproteolyticcleveagenearthetransmembranespan.LymphocytesandmonocytescanalsoshedL-selectinuponactivationalthoughthekineticsaresignificantlylower.AbroadrangeofactivatingagentsincludingC5a,fMLP,TNF,GM-CSF,IL-8areeffectiveininducingthisresponse.TheshedformofL-selectin(sL-selectin)isfunctionallyactiveandathighconcentrationscaninhibitleukocyteattachmenttoendothelium.ThemainsourceforsL-selectininserumseemstobetissuelocalizedleukocytes.Determinationofsoluble/circulatingL-selectincouldprovidemoredetailedinsightsintothepathologicalmodificationsduringvariousdiseases(allergy,deepvenousthrombosis,HIV,insulin-dependentdiabetesmellitus,KawasakiSyndrome,malignantB-cellpopulations,neonatalbacterialinfection,sepsis,surgery).

Synonyms:Leukocyte-EndothelialCellAdhesionMolecule-1,CD62L,LECAM-1,MEL-14antigen,LAM-1,LEU-8antigen,TQ1antigen