Antimicrobial peptide LL‐37 promotes bacterial phagocytosis by human macrophages

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

关键词: cathelicidin;    Fcγ;    R;    TLR;    innate immunity;    infection;   

DOI  :  10.1189/jlb.0513304

学科分类：生理学

来源: Federation of American Societies for Experimental Biology

【 摘 要 】

LL‐37/hCAP‐18istheonlyhumanmemberofthecathelicidinfamilyandplaysanimportantroleinkillingvariouspathogens,aswellasinimmunemodulation.Inthisstudy,weinvestigatedtheeffectofLL‐37onbacterialphagocytosisbymacrophagesanddemonstratethatLL‐37enhancesphagocytosisofIgG‐opsonizedGram‐negativeandGram‐positivebacteriainadose‐andtime‐dependentmannerbydTHP‐1cells.Inaddition,LL‐37enhancedphagocytosisofnonopsonizedEscherichiacolibyhumanmacrophages.Consistently,LL‐37elevatedtheexpressionofFcγRsonmacrophagesbutnotthecomplementreceptorsCD11band‐c.FurtherstudiesrevealedthattheexpressionofTLR4andCD14isalsoincreasedonLL‐37‐treatedmacrophages.SeverallinesofevidenceindicatedthattheFPR2/ALXreceptormediatedLL‐37‐inducedphagocytosis.However,TLR4signalingwasalsocoupledtothephagocyticresponse,asaspecificTLR4antibodysignificantlysuppressedphagocytosisofIgG‐opsonizedE.coliandnonopsonizedE.colibydTHP‐1cells.Finally,macrophagesfromCnlp−/−miceexhibiteddiminishedbacterialphagocytosiscomparedwithmacrophagesfromtheirWTlittermates.Inconclusion,wedemonstrateanovel,immune‐modulatorymechanismofLL‐37,whichmaycontributetobacterialclearance...

【 授权许可】

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