Type
Recombinant
Description
IL-21 isapleiotropiccytokineproducedbyCD4+Tcellsinresponsetoantigenicstimulation. Itsactiongenerallyenhancesantigen-specificresponsesofimmunecells. TheBIOLOGicaleffectsofIL-21 includeinductionofdifferentiationofTcells-stimulatedB-cellsintoplasmacellsandmemoryB-cells,stimulation(inconjuction)withIL-4 ofIgGproduction andinductionofapoptoticeffectsinB-cellsandstimulatedB-cellsintheabsenceofTcellsignaling. Additionally,IL-21 promotestheanti-tumoractivityofCD8+TcellsandNKcells. IL-21 exertsitseffectthroughbindingtoaspecifictypeI cytokinereceptor,IL-21R,whichalsocontainstheɣchain(ɣc)foundinothercytokinereceptorsincludingIL-2,IL-4,IL-7,IL-9 andIL-15. TheIL-21/IL-21RinteractiontriggersacascadeofeventswhichincludesactivationofthetyrosinekinasesJAK1andJAK3,followedbyactivationofthetranscriptionfactorsSTAT1andSTAT3.RecombinanthumanIL-21 isa15.4 kDaproteinconsistingof132 aminoacidresidues.
AminoAcidSequence
MHKSSPQGPDRLLIRLRHLIDIVEQLKIYENDLDPELLSAPQDVKGHCEHAAFACFQKAKLKPSNPGNNKTFIIDLVAQLRRRLPARRGGKKQKHIAKCPSCDSYEKRTPKEFLERLKWLLQKMIHQHLS
Source
E.coli
Purity
98%
BiologicalActivity
Assay#1:MeasuredbyitsABIlitytoincreaseproliferationinmousesplenocytesinducedbyanti-hCD40mAb.TheexpectedED50is15–20ng/ml.Assay#2:DeterminedbyitsabilitytostimulatetheproliferationofhumanANBL-6 cells.TheexpectedED50is≤1.0 ng/ml,correspondingtoaspecificactivityof≥1×106units/mg
Endotoxin
Endotoxinlevelis<0.1 ng/μgofprotein(<1EU/μg).
Reconstitution
Centrifugethevialpriortoopening.Reconstituteinwatertoaconcentrationof0.1–1.0 mg/ml.Donotvortex.Thissolutioncanbestoredat2–8°Cforupto1 week.Forextendedstorage,itisrecommendedtofurtherdiluteinabuffercontainingacarrierprotein(example0.1%BSA)andstoreinworkingaliquotsat –20°Cto –80°C.
Storage/Expiration
–20°C
