The teleost acute‐phase inflammatory response and caspase activation by a novel alarmin‐like ligand

[摘要] ThisstudytestedthehypothesisthatNCAMP‐1hasalarmin‐likepropertiesandactivatesthecaspase‐1‐bindingsiteincellsoftheteleostbonemarrow(equivalent).Inmammals,alarminshavebeenstudiedextensively;however,inteleosts,littleisknownabouttheiridentityandfunctions.Similartoalarmins,NCAMP‐1hasabroadspectrumofbacteriolyticactivity.NCAMP‐1isconstitutivelypresentinCFserum,andlevelswereincreasedfollowinginfectionwithEdwardsiellaictaluri.BindingtoAKcellswasdeterminedwithrNCAMP‐1andananti‐His‐tagantibody.InvitrotreatmentofAK(bonemarrowequivalent)orspleencellswithrNCAMP‐1increasedtheIL‐1βmessagethree‐tofivefoldat3h,6h,and9hpost‐treatment.TheassociationofNCAMP‐1withtheactivitiesofalarminATPandtheacuteinflammatoryresponsewasdemonstratedbyNCAMP‐1‐inducedP2X7RporeopeningandYO‐PRO‐1cellularinflux.TheassociationofNCAMP‐1bindingwithinflammasomeactivationwasdemonstratedbyNCAMP‐1activationofthecaspase‐1‐bindingsitefortetrapeptideZ‐YVAD‐FMK.Incompetitionassays,thistetrapeptidecompetitivelyinhibitedsubsequentbindingbythepan‐caspasesubstratetripeptideFAM‐VAD‐FMK.Lymphocyte‐likecellsfromthespleenwere16%+,andepithelialcellswerealsopositiveforNCAMP‐1.IHCstainingandconfocalmicroscopyconfirmedthecytosolicexistenceofNCAMP‐1inlymphoreticulartissueandIL‐1βinAKcells.CFTcelllinesG14Dand28S.3expressedNCAMP‐1inthecytosolandinstoragegranules.ThesestudiesstronglysuggestedthatNCAMP‐1isanalarmin‐likeligandwithsimilarbutdistinctactivitiestothoseofATPandHMGB‐1...

[学科分类] 生理学

[关键词] inflammation;cytokines;inflammasome;competitive inhibition;pathogens;innate immunity