Overview | Vascularcelladhesionmolecule-1(VCAM-1,CD106)isamemberoftheimmunoglobulingenesuperfamily.TwoformsofVCAM-1withsixorsevenextracellularIg-likedomainsariseduetoalternativesplicingfromaseven-domainVCAM-1(7DVCAM-1).7DVCAM-1isthedominantformexpressedbyculturedhumanendothelialcells[Cybulskyetal.,1991;Hessionetal.,1991].Homologyofdomains1through3withdomains4through6suggestsageneduplicationevent[Cybulskyetal.,1991;Hessionetal.,1991].TheCDNAof7DVCAM-1predictsacoreproteinofapproximately81kDawithsevensitesforN-linkedglycosylation.Uponcompleteglycosylationthematureproteinhasamolecularweightofapproximately102kDa.Thisobservationisingeneralagreementwiththe110kDaproteinimmunoprecipitatedfromcytokine-activatedendothelium[Carlosetal.,1990;Riceetal.,1990].
VCAM-1appearstohavebeenhighlyconservedthroughevolution.BothratandmouseVCAM-1arehighlyhomologousattheproteinleveltothehumanVCAM-1(77%and76%,respectively)[Hessionetal.,1992].
VCAM-1supportstheadhesionoflymphocytes,monocytes,naturalkillercells,eosinophilsandbasophils,throughitsinteractionwithintegrina4b1(VLA-4).VCAM-1/VLA-4interactionmediatesfirmadherenceofcirculatingnon-neutrophilicleukocytestoendothelium[Shararetal.,1995].VCAM-1alsoparticipatesinleukocyteadhesionoutsideofthevasculature,mediatingprecursorlymphocyteadhesiontobonemarrowstromalcells[Ryanetal.1991]andBcellbindingtolymphnodefolliculardendriticcells[Feedmanetal.,1992].VCAM-1isnotconstitutivelyexpressedonendothelium,butcanbeup-regulatedinvitroinresponsetoLPS,TNF-a,andIL-1[Carlos&Harlan,1990;Osbornetal.,1989],aswellastointerferon-gandIL-4[Masinovskyetal.1990].VCAM-1isalsopresentontissuemacrophages,dendritecells,bonemarrowfibroblasts,myoblastsandmyotubes.
AsolubleformofVCAM-1hasbeendescribed[DeMaeyer&DeMaeyer-Buignard,1995;Lobbetal.,1991],andsolubleVCAM-1hasbeenfoundinserum[Gearingetal.,1995].IncreasedlevelsofsolubleVCAM-1canbedetectedinseveraldiseasestates,includingcancer[Banksetal.,1993;Fortisetal.,1995;Gearing&Newman,1993;Laietal.,1995],autoimmunedisorders[Gearing&Newman,1993;Doreduffyetal.,1995;Gruschwitzetal.,1995;Masonetal.,1993;Mrowka&Sieberth,1995;Spronketal.,1994;Wellicomeetal.,1993],infections[Jakobsenetal.,1994]andinflammations[Gearing&Newman,1993;Mrowka&Sieberth,1995;Adamsetal.,1995;Limetal.,1995].
TestPrinciple:
Ananti-VCAM-1monoclonalantibodyisadsorbedontomicrowells.
SolubleVCAM-1presentinasampleorstandardthenbindstoantibodiesadsorbedtothemicrowells.Amixtureofbiotin-conjugatedmonoclonalanti-VCAM-1antibodyandStreptavidin-HRPconjugateisadded.Biotinylatedanti-VCAM-1antibodybindstoVCAM-1capturedbythefirstantibody.
Streptavidin-HRPbindstothebiotinylatedanti-VCAM-1.Unboundbiotinylatedanti-VCAM-1andStreptavidin-HRPconjugateisremovedwithawashstepandHRPsubstratesolutionisaddedtothewells.
ThepairofmonoclonalantibodiesusedinthisELISAdetectthesolubleformofVCAM-1presentinserum,plasma,urine,andotherBIOLOGicalfluids.
Anamountofcoloredproductisformed,proportionaltotheamountofsolubleVCAM-1presentinthesample.Thereactionisterminatedbyadditionofacidandabsorbanceismeasuredat450nm.AstandardcurveispreparedfromsixsolubleVCAM-1standarddilutionsandtheVCAM-1sampleconcentrationisdetermined.
Application:
TheVCAM-1ELISAisanenzyme-linkedimmunosorbentassayforquantitativedetectionofsolubleVascularCellAdhesionMolecule-1incellculturesupernatants,serum,plasma,orotherbiologicalfluids.TheVCAM-1ELISAisforresearchuseonly.Notforuseindiagnosticprocedures. |