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 ResearchConceptsAnaplasma 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 postinfectionDifferential Expression of the p44 Gene Family in the Agent of Human Granulocytic Ehrlichiosis
IJdo JW, Wu C, Telford SR, Fikrig E. Differential Expression of the p44 Gene Family in the Agent of Human Granulocytic Ehrlichiosis. Infection And Immunity 2002, 70: 5295-5298. PMID: 12183586, PMCID: PMC128253, DOI: 10.1128/iai.70.9.5295-5298.2002.Peer-Reviewed Original ResearchConceptsP44 geneDifferential expressionHuman granulocytic ehrlichiosisGene familyAntigenic variationHGE bacteriaTransmission feedingGranulocytic ehrlichiosisGenesHypervariable regionInfected C3H miceP44 expressionTick transmissionExpressionSCID miceC3H miceHGE infectionMurine modelInfected ticksSalivary glandsNymphal ticksMiceTicksEhrlichiosisBacteriaComparative reactivity of human sera to recombinant VlsE and other Borrelia burgdorferi antigens in class-specific enzyme-linked immunosorbent assays for Lyme borreliosis
Magnarelli LA, Lawrenz M, Norris SJ, Fikrig E. Comparative reactivity of human sera to recombinant VlsE and other Borrelia burgdorferi antigens in class-specific enzyme-linked immunosorbent assays for Lyme borreliosis. Journal Of Medical Microbiology 2002, 51: 649-655. PMID: 12171295, DOI: 10.1099/0022-1317-51-8-649.Peer-Reviewed Original ResearchConceptsEnzyme-linked immunosorbent assayIgG antibodiesErythema migransIgM antibodiesLyme borreliosisPhysician-diagnosed erythema migransOnset of illnessVlsE antigenB. burgdorferi infectionBorrelia burgdorferi antigensEnzyme-linked immunosorbentHuman granulocytic ehrlichiosisHuman serumOuter surface protein CRheumatoid arthritisBorrelia burgdorferi sensu strictoOral infectionBurgdorferi infectionFalse-positive reactionsBurgdorferi sensu strictoSera crossLouse-borneLaboratory diagnosisNormal serumGranulocytic ehrlichiosis
2001
Exploitation of Interleukin-8-Induced Neutrophil Chemotaxis by the Agent of Human Granulocytic Ehrlichiosis
Akkoyunlu M, Malawista S, Anguita J, Fikrig E. Exploitation of Interleukin-8-Induced Neutrophil Chemotaxis by the Agent of Human Granulocytic Ehrlichiosis. Infection And Immunity 2001, 69: 5577-5588. PMID: 11500432, PMCID: PMC98672, DOI: 10.1128/iai.69.9.5577-5588.2001.Peer-Reviewed Original ResearchConceptsHuman granulocytic ehrlichiosisInterleukin-8Granulocytic ehrlichiosisHGE bacteriaUpregulation of CXCR2IL-8 receptorsIL-8 productionIL-8 secretionSite of infectionInfected HL-60 cellsObligate intracellular bacteriumChemotaxis chamber assayNeutrophils migrateNeutrophil migrationNeutrophil chemotaxisImmunodeficient miceControl animalsBacterial disseminationHost defensePromyelocytic cell lineChamber assayIntracellular bacteriumHL-60 cellsRetinoic acidNeutrophil lineageReactivity of serum samples of dogs and horses tested by use of class-specific recombinant-based enzyme-linked immunosorbent assays for detection of granulocytic ehrlichiosis.
Magnarelli LA, Ijdo JW, Van Andel AE, Wu C, Oliver JH, Fikrig E. Reactivity of serum samples of dogs and horses tested by use of class-specific recombinant-based enzyme-linked immunosorbent assays for detection of granulocytic ehrlichiosis. American Journal Of Veterinary Research 2001, 62: 1365-9. PMID: 11560261, DOI: 10.2460/ajvr.2001.62.1365.Peer-Reviewed Original ResearchConceptsIgG antibodiesSerum samplesHGE agentGranulocytic ehrlichiosisClient-owned dogsDog serum samplesHuman granulocytic ehrlichiosis (HGE) agentEnzyme-linked immunosorbentPositive resultsWestern blot analysisTick-infested areasEhrlichia phagocytophila genogroupTotal immunoglobulinHorse serum samplesPromyelocytic leukemia cellsClinical relevanceHuman promyelocytic leukemia cellsProtein antigensIgMELISADogsLeukemia cellsAntibodiesBlot analysisAntigenRecombinant Protein-44-Based Class-Specific Enzyme-Linked Immunosorbent Assays for Serologic Diagnosis of Human Granulocytic Ehrlichiosis
Magnarelli L, IJdo J, Wu C, Fikrig E. Recombinant Protein-44-Based Class-Specific Enzyme-Linked Immunosorbent Assays for Serologic Diagnosis of Human Granulocytic Ehrlichiosis. European Journal Of Clinical Microbiology & Infectious Diseases 2001, 20: 482-485. PMID: 11561804, DOI: 10.1007/s100960100542.Peer-Reviewed Original ResearchConceptsPolyvalent enzyme-linked immunosorbent assaysClass-specific enzyme-linked immunosorbent assaysEnzyme-linked immunosorbent assayIndirect fluorescent-antibody analysisFluorescent antibody analysisImmunosorbent assaySpecificity testsIgG antibodiesHigh sensitivityHuman granulocytic ehrlichiosisHuman serumGranulocytic ehrlichiosisWhole cell antigenAntibody analysisImmunoglobulin M antibodiesOnset of illnessSerologic diagnosisSerum samplesHuman granulocytic ehrlichiosis (HGE) agentPatient 3False-positive resultsIgM antibodiesM antibodiesTotal immunoglobulinTotal antibodyCoinfection with Borrelia burgdorferi and the Agent of Human Granulocytic Ehrlichiosis Alters Murine Immune Responses, Pathogen Burden, and Severity of Lyme Arthritis
Thomas V, Anguita J, Barthold S, Fikrig E. Coinfection with Borrelia burgdorferi and the Agent of Human Granulocytic Ehrlichiosis Alters Murine Immune Responses, Pathogen Burden, and Severity of Lyme Arthritis. Infection And Immunity 2001, 69: 3359-3371. PMID: 11292759, PMCID: PMC98295, DOI: 10.1128/iai.69.5.3359-3371.2001.Peer-Reviewed Original ResearchConceptsHuman granulocytic ehrlichiosisLyme arthritisDual infectionBacterial burdenImmune responseTumor necrosis factor-alpha levelsB. burgdorferiElevated IL-6 levelsNecrosis factor-alpha levelsGranulocytic ehrlichiosisIL-6 levelsAgent of HGEMurine immune responseBorrelia burgdorferiTick-borne illnessMurine Lyme arthritisSevere Lyme arthritisCoinfection of miceIFN-gamma receptor expressionInfected miceInterleukin-12Receptor expressionGamma interferonArthritisPathogen burdenEvaluation of a polyvalent enzyme-linked immunosorbent assay incorporating a recombinant p44 antigen for diagnosis of granulocytic ehrlichiosis in dogs and horses.
Magnarelli LA, Ijdo JW, Van Andel AE, Wu C, Fikrig E. Evaluation of a polyvalent enzyme-linked immunosorbent assay incorporating a recombinant p44 antigen for diagnosis of granulocytic ehrlichiosis in dogs and horses. American Journal Of Veterinary Research 2001, 62: 29-32. PMID: 11197555, DOI: 10.2460/ajvr.2001.62.29.Peer-Reviewed Original ResearchConceptsEquine samplesPolyvalent ELISAPolyvalent enzyme-linked immunosorbentGranulocytic ehrlichiosisIFA stainingEquine serum samplesE risticiiEhrlichia canisCanine serum samplesCanine samplesSpecific recombinant antigensE equiHorsesEhrlichiosisPercentage of samplesIndirect fluorescent antibody stainingRecombinant antigensDogsWhole cell antigenCanisEquiELISA resultsSerum samplesPresent studyFluorescent antibody stainingPathogenic strategies of Anaplasma phagocytophilum, a unique bacterium that colonizes neutrophils
Carlyon J, Fikrig E. Pathogenic strategies of Anaplasma phagocytophilum, a unique bacterium that colonizes neutrophils. 2001, 301-330. DOI: 10.1017/cbo9780511754845.014.Peer-Reviewed Original Research
2000
Serologic confirmation of Ehrlichia equi and Borrelia burgdorferi infections in horses from the northeastern United States.
Magnarelli LA, Ijdo JW, Van Andel AE, Wu C, Padula SJ, Fikrig E. Serologic confirmation of Ehrlichia equi and Borrelia burgdorferi infections in horses from the northeastern United States. Journal Of The American Veterinary Medical Association 2000, 217: 1045-50. PMID: 11019714, DOI: 10.2460/javma.2000.217.1045.Peer-Reviewed Original ResearchConceptsB burgdorferiClinical signsGranulocytic ehrlichiosisSerum samplesDetectable serum antibodiesImmunoblot analysisIndirect fluorescent antibody stainingBorrelial antibodiesTick-infested areasRecombinant protein antigensProspective studyDetectable antibodiesSerum antibodiesSerologic confirmationFluorescent antibody stainingE equiAntibody reactivityClinical relevanceEtiologic agentClinical diagnosisEqui antibodiesProtein antigensEhrlichia equiELISAAntibodiesGranulocytic 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 ResearchThe Emergence of Another Tickborne Infection in the 12-Town Area around Lyme, Connecticut: Human Granulocytic Ehrlichiosis
IJdo J, Meek J, Cartter M, Magnarelli L, Wu C, Tenuta S, Fikrig E, Ryder R. The Emergence of Another Tickborne Infection in the 12-Town Area around Lyme, Connecticut: Human Granulocytic Ehrlichiosis. The Journal Of Infectious Diseases 2000, 181: 1388-1393. PMID: 10751139, DOI: 10.1086/315389.Peer-Reviewed Original ResearchConceptsHuman granulocytic ehrlichiosisTickborne infectionProspective population-based surveillanceGranulocytic ehrlichiosisCommon tickborne infectionPopulation-based surveillancePrimary care providersSubset of seraIndirect fluorescent antibody methodIllness suggestiveCare providersLaboratory evidenceImportant causeProbable casesFluorescent antibody methodImmunoblot assayLyme diseaseInfectionAntibody methodIncidenceEhrlichiosisLymeMorbidityDiseaseSuggestiveGamma Interferon Dominates the Murine Cytokine Response to the Agent of Human Granulocytic Ehrlichiosis and Helps To Control the Degree of Early Rickettsemia
Akkoyunlu M, Fikrig E. Gamma Interferon Dominates the Murine Cytokine Response to the Agent of Human Granulocytic Ehrlichiosis and Helps To Control the Degree of Early Rickettsemia. Infection And Immunity 2000, 68: 1827-1833. PMID: 10722570, PMCID: PMC97354, DOI: 10.1128/iai.68.4.1827-1833.2000.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsBacteremiaConcanavalin ACytokinesDisease ProgressionDose-Response Relationship, DrugEhrlichiosisEnzyme-Linked Immunosorbent AssayFemaleHL-60 CellsHumansImmunoglobulin GInterferon-gammaMiceMice, Inbred C3HNeutrophilsReverse Transcriptase Polymerase Chain ReactionRickettsiaSpleenTime FactorsT-LymphocytesConceptsIFN-gamma-deficient miceHuman granulocytic ehrlichiosisIFN-gamma levelsDay 8Cytokine responsesIFN-gammaGamma interferonCells/HGE bacteriaGranulocytic ehrlichiosisIFN-gamma-independent mechanismMurine cytokine responsesTime pointsAgent of HGEMore IFN-gammaC3H/HeNLess interleukin-4IFN-gamma responsesMurine infection modelLater time pointsObligate intracellular bacteriumTh1 phenotypeC57BL/6 miceDNA burdenImmunocompetent mice
1999
Serodiagnosis of Human Granulocytic Ehrlichiosis by a Recombinant HGE-44-Based Enzyme-Linked Immunosorbent Assay
Ijdo J, Wu C, Magnarelli L, Fikrig E. Serodiagnosis of Human Granulocytic Ehrlichiosis by a Recombinant HGE-44-Based Enzyme-Linked Immunosorbent Assay. Journal Of Clinical Microbiology 1999, 37: 3540-3544. PMID: 10523549, PMCID: PMC85687, DOI: 10.1128/jcm.37.11.3540-3544.1999.Peer-Reviewed Original ResearchConceptsPolyvalent enzyme-linked immunosorbent assaysEnzyme-linked immunosorbent assayRecombinant enzyme-linked immunosorbent assayIndirect fluorescent-antibody assaySerum samplesPatient serum samplesFluorescent-antibody assayCurrent antibodyNormal serum samplesImmunosorbent assayHuman granulocytic ehrlichiosisHuman monocytic ehrlichiosisSuitable antigenHigh costGranulocytic ehrlichiosisSerologic testing of horses for granulocytic ehrlichiosis, using indirect fluorescent antibody staining and immunoblot analysis.
Magnarelli L, Van Andel A, Ijdo J, Heimer R, Fikrig E. Serologic testing of horses for granulocytic ehrlichiosis, using indirect fluorescent antibody staining and immunoblot analysis. American Journal Of Veterinary Research 1999, 60: 631-5. PMID: 10328436, DOI: 10.2460/ajvr.1999.60.05.631.Peer-Reviewed Original ResearchConceptsIndirect fluorescent antibodyNCH-1 strainPolymerase chain reactionGranulocytic ehrlichiosisSeropositivity rateSerum samplesBlood samples
1998
Reactivity of Human Sera to Different Strains of Granulocytic Ehrlichiae in Immunodiagnostic Assays
Magnarelli L, IJdo J, Dumler J, Heimer R, Fikrig E. Reactivity of Human Sera to Different Strains of Granulocytic Ehrlichiae in Immunodiagnostic Assays. The Journal Of Infectious Diseases 1998, 178: 1835-1838. PMID: 9815246, DOI: 10.1086/314516.Peer-Reviewed Original ResearchConceptsNCH-1 strainIndirect IFAHuman granulocytic ehrlichiosis (HGE) agentHuman granulocytic ehrlichiosisWestern blot analysisInfected neutrophilsPromyelocytic leukemia cellsHuman promyelocytic leukemia cellsAntibody detectionGranulocytic ehrlichiosisEhrlichia equiDifferent strainsHuman isolatesLeukemia cellsSerumImmunodiagnostic assaysBlot analysisGranulocytic ehrlichiaeIFA analysisHuman serumIFAEhrlichiaeAssaysSeropositivityPatientsHuman granulocytic ehrlichiosis, a tick-borne disease.
Ijdo JW, Fikrig E. Human granulocytic ehrlichiosis, a tick-borne disease. Nederlands Tijdschrift Voor Geneeskunde 1998, 142: 1778-81. PMID: 9856144.Peer-Reviewed Original ResearchConceptsPresence of leukopeniaRecent tick biteDay of admissionWhite cell countPeripheral blood smearHuman granulocytic ehrlichiosisElevated transaminasesTick-borne diseaseSevere headachePlatelet countTick biteNormal limitsCell countBlood smearsGranulocytic ehrlichiosisDays durationFull recoveryMyalgiaEhrlichiosisHeadacheWeeksLaboratory resultsLaboratory testsDurationCount