2014
Anaplasma phagocytophilum surface protein AipA mediates invasion of mammalian host cells
Seidman D, Ojogun N, Walker NJ, Mastronunzio J, Kahlon A, Hebert KS, Karandashova S, Miller DP, Tegels BK, Marconi RT, Fikrig E, Borjesson DL, Carlyon JA. Anaplasma phagocytophilum surface protein AipA mediates invasion of mammalian host cells. Cellular Microbiology 2014, 16: 1133-1145. PMID: 24612118, PMCID: PMC4115035, DOI: 10.1111/cmi.12286.Peer-Reviewed Original ResearchConceptsGranulocytic anaplasmosisObligate intracellular bacteriumVivo infectionInfectionPhagocytophilum infectionTransmission feedingObligate intracellular pathogensInfected ticksIntracellular pathogensNon-phagocytic cellsIntracellular bacteriumHL-60 cellsHost cell invasionCell invasionAnaplasma phagocytophilumPeptide-specific antiserumOwn uptakeHost cellsAttractive targetInternalization stepMammalian cellsInvasion proteinsSurface proteinsCell morphotypesCells
2012
Anaplasma phagocytophilum Asp14 Is an Invasin That Interacts with Mammalian Host Cells via Its C Terminus To Facilitate Infection
Kahlon A, Ojogun N, Ragland SA, Seidman D, Troese MJ, Ottens AK, Mastronunzio JE, Truchan HK, Walker NJ, Borjesson DL, Fikrig E, Carlyon JA. Anaplasma phagocytophilum Asp14 Is an Invasin That Interacts with Mammalian Host Cells via Its C Terminus To Facilitate Infection. Infection And Immunity 2012, 81: 65-79. PMID: 23071137, PMCID: PMC3536139, DOI: 10.1128/iai.00932-12.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SequenceAnaplasma phagocytophilumAnimalsBacterial Outer Membrane ProteinsBinding SitesCell AdhesionCell Line, TumorEhrlichiaEhrlichiosisGene Expression Regulation, BacterialGlutathione TransferaseHL-60 CellsHumansMembrane GlycoproteinsMembrane ProteinsMiceMolecular Sequence DataProtein BindingProtein Structure, TertiaryProteomeSequence Analysis, ProteinTranscription, GeneticUp-RegulationConceptsMammalian host cellsHost cellsReticulate cellsOuter membrane protein candidatesSurface proteinsOuter membrane protein AMembrane protein AA. phagocytophilum-infected ticksObligate intracellular bacteriumA. phagocytophilumGlutathione S-transferaseTranscriptional profilingSurface proteomeC-terminusAffinity purificationFamily AnaplasmataceaeProtein candidatesSelective biotinylationCellular invasionAsp14Transmission feedingAmino acidsS-transferaseIntracellular bacteriumP-selectin glycoprotein ligand-1Anaplasma phagocytophilum Outer Membrane Protein A Interacts with Sialylated Glycoproteins To Promote Infection of Mammalian Host Cells
Ojogun N, Kahlon A, Ragland SA, Troese MJ, Mastronunzio JE, Walker NJ, VieBrock L, Thomas RJ, Borjesson DL, Fikrig E, Carlyon JA. Anaplasma phagocytophilum Outer Membrane Protein A Interacts with Sialylated Glycoproteins To Promote Infection of Mammalian Host Cells. Infection And Immunity 2012, 80: 3748-3760. PMID: 22907813, PMCID: PMC3486060, DOI: 10.1128/iai.00654-12.Peer-Reviewed Original ResearchConceptsMammalian host cellsHuman granulocytic anaplasmosisHost cellsHL-60 cellsA. phagocytophilum organismsExtracellular domainP-selectin glycoprotein-1Outer Membrane Protein ASialylated glycoproteinsA. phagocytophilum infectionA. phagocytophilum-infected ticksN-terminal regionMembrane protein AObligate intracellular bacteriumAmino acids 19HGA patientsPhagocytophilum infectionInfectionTransmission feedingGlutathione S-transferaseGranulocytic anaplasmosisIntracellular bacteriumGlycoprotein 1Anaplasma phagocytophilumA. phagocytophilum
2009
Toll-like Receptor 7 Mitigates Lethal West Nile Encephalitis via Interleukin 23-Dependent Immune Cell Infiltration and Homing
Town T, Bai F, Wang T, Kaplan AT, Qian F, Montgomery RR, Anderson JF, Flavell RA, Fikrig E. Toll-like Receptor 7 Mitigates Lethal West Nile Encephalitis via Interleukin 23-Dependent Immune Cell Infiltration and Homing. Immunity 2009, 30: 242-253. PMID: 19200759, PMCID: PMC2707901, DOI: 10.1016/j.immuni.2008.11.012.Peer-Reviewed Original ResearchConceptsToll-like receptor 7West Nile virusReceptor 7WNV infectionImmune cell infiltrationLethal WNV infectionMyeloid differentiation factorIL-23 p19IL-23 responsesIL-12 p40West Nile encephalitisIL-12 p35Infected target cellsHost defense mechanismsRNA flavivirusInnate cytokinesWNV encephalitisInterleukin-12Cell infiltrationImmune cellsTarget organsVariable severityMiceTarget cellsTissue concentrations
2007
Anaplasma phagocytophilum specifically induces tyrosine phosphorylation of ROCK1 during infection
Thomas V, Fikrig E. Anaplasma phagocytophilum specifically induces tyrosine phosphorylation of ROCK1 during infection. Cellular Microbiology 2007, 9: 1730-1737. PMID: 17346310, DOI: 10.1111/j.1462-5822.2007.00908.x.Peer-Reviewed Original ResearchConceptsAnaplasma phagocytophilumPSGL-1Non-antibiotic strategiesHuman granulocytic anaplasmosisA. phagocytophilum infectionA. phagocytophilum-infected cellsTick-borne agentsPolymorphonuclear leucocytesPromyelocytic cell linePhagocytophilum infectionObligate intracellular pathogensInfectionTyrosine phosphorylationIntracellular pathogensGranulocytic anaplasmosisCell linesROCK1SykPhagocytophilumPhosphorylationNeutrophilsLeucocytesAntibodies
2006
Mechanisms of evasion of neutrophil killing by Anaplasma phagocytophilum
Carlyon JA, Fikrig E. Mechanisms of evasion of neutrophil killing by Anaplasma phagocytophilum. Current Opinion In Hematology 2006, 13: 28-33. PMID: 16319684, DOI: 10.1097/01.moh.0000190109.00532.56.Peer-Reviewed Original ResearchConceptsApoptosis differentiation programMitochondrial membrane integrityA. phagocytophilumCaspase-3 activationBacterium altersMolecular machineryVacuolar membraneTranscription factorsDifferentiation programMammalian hostsSecretory vesiclesAnaplasma phagocytophilumCytoplasmic compartmentGene expressionPromoter activityAntiapoptotic genesNADPH oxidase assemblyOxidase assemblyNeutrophil gene expressionHost cellsBacterial uptakeNADPH oxidase componentsMechanisms of evasionMembrane integrityCytochrome b558
2005
Anaplasma phagocytophilum Modulates gp91phox Gene Expression through Altered Interferon Regulatory Factor 1 and PU.1 Levels and Binding of CCAAT Displacement Protein
Thomas V, Samanta S, Wu C, Berliner N, Fikrig E. Anaplasma phagocytophilum Modulates gp91phox Gene Expression through Altered Interferon Regulatory Factor 1 and PU.1 Levels and Binding of CCAAT Displacement Protein. Infection And Immunity 2005, 73: 208-218. PMID: 15618156, PMCID: PMC538944, DOI: 10.1128/iai.73.1.208-218.2005.Peer-Reviewed Original ResearchMeSH KeywordsAnaplasma phagocytophilumDNA-Binding ProteinsGene Expression RegulationHL-60 CellsHomeodomain ProteinsHumansInterferon Regulatory Factor-1Membrane GlycoproteinsNADPH Oxidase 2NADPH OxidasesNuclear ProteinsPhosphoproteinsPhosphorylationPromoter Regions, GeneticProto-Oncogene ProteinsRepressor ProteinsSTAT1 Transcription FactorTrans-ActivatorsTranscription FactorsTranscription, GeneticConceptsCCAAT displacement proteinRegulatory factor 1IRF-1IRF-1 promoterRegulation of genesA. phagocytophilum-infected cellsFirst molecular mechanismFactor 1Interferon regulatory factor 1IFN-gamma signalingActivator proteinGene transcriptionAnaplasma phagocytophilumTranscriptional inhibitionGene expressionMolecular mechanismsNuclear extractsGamma interferon stimulationPhosphorylated STAT1Interferon stimulationGenesA. phagocytophilum infectionProteinProtein expressionReduced expression
2004
Toll-like receptor 3 mediates West Nile virus entry into the brain causing lethal encephalitis
Wang T, Town T, Alexopoulou L, Anderson JF, Fikrig E, Flavell RA. Toll-like receptor 3 mediates West Nile virus entry into the brain causing lethal encephalitis. Nature Medicine 2004, 10: 1366-1373. PMID: 15558055, DOI: 10.1038/nm1140.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsApoptosisBlood-Brain BarrierBrainEncephalitisImmunohistochemistryInflammationMembrane GlycoproteinsMiceMice, Inbred C57BLMice, KnockoutMicroscopy, FluorescencePermeabilityReceptors, Cell SurfaceSignal TransductionToll-Like Receptor 3Toll-Like ReceptorsTumor Necrosis Factor-alphaViral LoadWest Nile virusConceptsToll-like receptor 3West Nile virusWNV infectionViral loadInflammatory responseReceptor 3Blood-brain barrier compromiseTLR3-deficient miceWest Nile virus entryLethal WNV infectionBlood-brain barrierWild-type miceNeuronal injuryIntracerebroventricular administrationBrain infectionCytokine productionBrain penetrationTumor necrosisTLR3 stimulationLethal encephalitisBarrier compromiseVariable severityInfectionVirus entryNile virus
2003
Invasion and survival strategies of Anaplasma phagocytophilum
Carlyon JA, Fikrig E. Invasion and survival strategies of Anaplasma phagocytophilum. Cellular Microbiology 2003, 5: 743-754. PMID: 14531890, DOI: 10.1046/j.1462-5822.2003.00323.x.Peer-Reviewed Original ResearchMeSH KeywordsAnaplasma phagocytophilumAnimalsApoptosisBiological TransportChemokinesEhrlichiosisHumansLysosomesMembrane GlycoproteinsNADPH OxidasesNeutrophilsSuperoxidesConceptsAnaplasma phagocytophilumA. phagocytophilumHuman granulocytic ehrlichiosisHostile intracellular environmentTick-borne zoonosisObligate intracellular bacteriumHost neutrophilsNeutrophil adhesionInnate immunityPolymorphonuclear leucocytesAetiological agentGranulocytic ehrlichiosisIntracellular bacteriumNeutrophilsMicrobicidal activityPhagocytophilumHost cellsProteolytic compoundsAcidic lysosomesBacteria-containing phagosomesKey playersLeucocytesImmunityEhrlichiosisPhagocytesMurine neutrophils require α1,3-fucosylation but not PSGL-1 for productive infection with Anaplasma phagocytophilum
Carlyon JA, Akkoyunlu M, Xia L, Yago T, Wang T, Cummings RD, McEver RP, Fikrig E. Murine neutrophils require α1,3-fucosylation but not PSGL-1 for productive infection with Anaplasma phagocytophilum. Blood 2003, 102: 3387-3395. PMID: 12869507, DOI: 10.1182/blood-2003-02-0621.Peer-Reviewed Original ResearchConceptsWild-type miceP-selectin glycoprotein ligand-1Murine neutrophilsCommon tick-borne diseaseAnaplasma phagocytophilumFuc-TIVHuman granulocytic ehrlichiosisPSGL-1 expressionTick-borne diseaseNeutrophil expressionInfection burdenMurine infectionNeutrophilsGranulocytic ehrlichiosisPhagocytophilum infectionMiceHuman neutrophilsSimilar molecular featuresInfectionProductive infectionSialidase treatmentLigand 1PhagocytophilumMolecular featuresFuc-TVIIStructurally Distinct Requirements for Binding of P-selectin Glycoprotein Ligand-1 and Sialyl Lewis x to Anaplasma phagocytophilum and P-selectin*
Yago T, Leppänen A, Carlyon JA, Akkoyunlu M, Karmakar S, Fikrig E, Cummings RD, McEver RP. Structurally Distinct Requirements for Binding of P-selectin Glycoprotein Ligand-1 and Sialyl Lewis x to Anaplasma phagocytophilum and P-selectin*. Journal Of Biological Chemistry 2003, 278: 37987-37997. PMID: 12847092, DOI: 10.1074/jbc.m305778200.Peer-Reviewed Original Research
2002
Repression of rac2 mRNA Expression by Anaplasma phagocytophila Is Essential to the Inhibition of Superoxide Production and Bacterial Proliferation
Carlyon JA, Chan WT, Galán J, Roos D, Fikrig E. Repression of rac2 mRNA Expression by Anaplasma phagocytophila Is Essential to the Inhibition of Superoxide Production and Bacterial Proliferation. The Journal Of Immunology 2002, 169: 7009-7018. PMID: 12471136, DOI: 10.4049/jimmunol.169.12.7009.Peer-Reviewed Original ResearchConceptsInfected HL-60 cellsHL-60 cellsAnaplasma phagocytophilaMRNA expressionNADPH oxidaseRetinoic acid-differentiated HL-60 cellsBacterial intracellular survivalHuman granulocytic ehrlichiosisNADPH oxidase activityNADPH oxidase activationQuantitative RT-PCRCMV immediate-early promoterInfected neutrophilsEtiologic agentGranulocytic ehrlichiosisRT-PCR analysisA. phagocytophilaIntracellular survivalSuperoxide productionOxidase activationNeutrophilsProtein expressionRT-PCRImmediate early promoterH postinfectionThe Lyme Disease Vaccine Takes Its Toll
Thomas V, Fikrig E. The Lyme Disease Vaccine Takes Its Toll. Vector-Borne And Zoonotic Diseases 2002, 2: 217-222. PMID: 12804162, DOI: 10.1089/153036602321653798.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsAntibodies, BacterialAntigens, SurfaceBacterial Outer Membrane ProteinsBacterial VaccinesBorrelia burgdorferiHumansLipoproteinsLyme DiseaseLyme Disease VaccinesMembrane GlycoproteinsMiceMice, KnockoutReceptors, Cell SurfaceToll-Like Receptor 1Toll-Like Receptor 2Toll-Like ReceptorsConceptsTLR2-deficient miceToll-like receptorsPathogen-associated molecular patternsOspA antibodiesSpecific Toll-like receptorsBorrelia burgdorferi outer surface proteinDetectable humoral responseMolecular patternsProtective immune responseLyme disease vaccineDistinct pathogen-associated molecular patternsVaccine recipientsHumoral responseOspA vaccineCell surface expressionOspA vaccinationImmune responseDisease vaccineInnate responseTLR2Protective responseOuter surface proteinsTLR1Lyme diseaseDevelopment of responsesHyporesponsiveness to vaccination with Borrelia burgdorferi OspA in humans and in TLR1- and TLR2-deficient mice
Alexopoulou L, Thomas V, Schnare M, Lobet Y, Anguita J, Schoen RT, Medzhitov R, Fikrig E, Flavell RA. Hyporesponsiveness to vaccination with Borrelia burgdorferi OspA in humans and in TLR1- and TLR2-deficient mice. Nature Medicine 2002, 8: 878-884. PMID: 12091878, DOI: 10.1038/nm732.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsAntibodies, BacterialAntigens, SurfaceBacterial Outer Membrane ProteinsBacterial VaccinesBorrelia burgdorferiCell SeparationCells, CulturedDrosophila ProteinsHumansInterleukinsLipoproteinsLyme Disease VaccinesMacrophagesMembrane GlycoproteinsMiceMice, KnockoutReceptors, Cell SurfaceSignal TransductionToll-Like Receptor 1Toll-Like Receptor 2Toll-Like ReceptorsConceptsToll-like receptor 1Less tumor necrosis factorTLR2-deficient miceLow antibody titersLyme disease vaccineTumor necrosis factorLow cell surface expressionOuter surface lipoproteinsVaccine recipientsAntibody titersInterleukin-6Cell surface expressionNecrosis factorOspA vaccinationDisease vaccineLow respondersInnate responseTLR2Low titersReceptor 1Substantial titersVaccinationMiceTLR1Borrelia burgdorferi
2000
Granulocytic Ehrlichiosis in Mice Deficient in Phagocyte Oxidase or Inducible Nitric Oxide Synthase
Banerjee R, Anguita J, Fikrig E. Granulocytic Ehrlichiosis in Mice Deficient in Phagocyte Oxidase or Inducible Nitric Oxide Synthase. Infection And Immunity 2000, 68: 4361-4362. PMID: 10858261, PMCID: PMC101771, DOI: 10.1128/iai.68.7.4361-4362.2000.Peer-Reviewed Original ResearchCutting Edge: Infection by the Agent of Human Granulocytic Ehrlichiosis Prevents the Respiratory Burst by Down-Regulating gp91phox
Banerjee R, Anguita J, Roos D, Fikrig E. Cutting Edge: Infection by the Agent of Human Granulocytic Ehrlichiosis Prevents the Respiratory Burst by Down-Regulating gp91phox. The Journal Of Immunology 2000, 164: 3946-3949. PMID: 10754283, DOI: 10.4049/jimmunol.164.8.3946.Peer-Reviewed Original ResearchConceptsHGE bacteriaNADPH oxidase enzyme complexHL-60 cellsNADPH oxidaseHuman granulocytic ehrlichiosisEnzyme complexPromyelocytic cell lineTick-borne pathogensInfected cellsCell linesOrganismsMRNA levelsGp91phox proteinRT-PCRDirect inhibitionBacteriaFACS analysisPathogensMRNA expressionOxidaseGenerate superoxide anionCellsRespiratory burstSplenic neutrophilsMicrobes
1997
B7-1 and B7-2 monoclonal antibodies modulate the severity of murine Lyme arthritis
Anguita J, Roth R, Samanta S, Gee RJ, Barthold SW, Mamula M, Fikrig E. B7-1 and B7-2 monoclonal antibodies modulate the severity of murine Lyme arthritis. Infection And Immunity 1997, 65: 3037-3041. PMID: 9234751, PMCID: PMC175428, DOI: 10.1128/iai.65.8.3037-3041.1997.Peer-Reviewed Original ResearchConceptsLyme arthritisMurine Lyme arthritisB7-1Monoclonal antibodiesCostimulatory moleculesB7-2Immune responseInterleukin-4C3H/HeN miceB7-2 costimulatory moleculesExperimental Lyme arthritisB7-2 expressionMurine Lyme borreliosisDegree of arthritisBorrelia burgdorferi infectionSplenocyte proliferative responseDose-dependent increaseHost immune responseT cell differentiationIL-10Antibody levelsIL-12HeN miceBurgdorferi infectionProliferative response
1996
Protective antibodies in murine Lyme disease arise independently of CD40 ligand.
Fikrig E, Barthold SW, Chen M, Grewal IS, Craft J, Flavell RA. Protective antibodies in murine Lyme disease arise independently of CD40 ligand. The Journal Of Immunology 1996, 157: 1-3. PMID: 8683101, DOI: 10.4049/jimmunol.157.1.1.Peer-Reviewed Original ResearchConceptsCD40L-deficient miceCD40 ligand-deficient miceMurine Lyme diseaseRegression of arthritisTransfer of serumDependent immune responsesIgG2b AbsAcute arthritisControl miceProtective antibodiesIg class switchingCD40 ligandImmune responseImmunodeficient miceLyme borreliosisLyme diseaseMiceBorrelia burgdorferiB. burgdorferiClass switchingArthritisBurgdorferiAbInfectionDisease