1 3953 120 LOCUS-SPECIFIC REVERSIBLE DNA METHYLATION REGULATES TRANSIENT IL-10 EXPRESSION IN TH1 CELLS. IL-10 IS A PLEIOTROPIC CYTOKINE WITH MULTIFACETED FUNCTIONS IN ESTABLISHING IMMUNE HOMEOSTASIS. ALTHOUGH EXPRESSED BY TH1 AND TH2 CELLS, CONVENTIONAL TH1 CELLS PRODUCE MARGINAL LEVELS OF IL-10 COMPARED WITH THEIR TH2 COUNTERPARTS. IN THIS STUDY, WE INVESTIGATED THE EPIGENETIC MECHANISMS OF IL-10 GENE EXPRESSION IN TH1 CELLS. BIOINFORMATICS EMBOSS CPG PLOT ANALYSIS AND BISULFITE PYROSEQUENCING REVEALED THREE CPG DNA METHYLATION SITES IN THE IL-10 GENE LOCUS. PROGRESSIVE DNA METHYLATION AT ALL OF THE CPG REGIONS OF INTEREST (ROIS) ESTABLISHED A REPRESSIVE PROGRAM OF IL-10 GENE EXPRESSION IN TH1 CELLS. INTERESTINGLY, TH1 CELLS TREATED WITH IL-12 AND IL-27 CYTOKINES, THEREBY MIMICKING A CHRONIC INFLAMMATORY CONDITION IN VIVO, DISPLAYED A SIGNIFICANT INCREASE IN IL-10 PRODUCTION THAT WAS ACCOMPANIED BY SELECTIVE DNA DEMETHYLATION AT ROI 3 LOCATED IN INTRON 3. IL-10-PRODUCING T CELLS ISOLATED FROM LYMPHOCYTIC CHORIOMENINGITIS VIRUS-INFECTED MICE ALSO SHOWED ENHANCED DNA DEMETHYLATION AT ROI 3. BINDING OF STAT1 AND STAT3 TO DEMETHYLATED ROI 3 ENHANCED IL-10 EXPRESSION IN AN IL-12/IL-27-DEPENDENT MANNER. ACCORDINGLY, CD4(+) T CELLS ISOLATED FROM STAT1- OR STAT3-KNOCKOUT MICE WERE SIGNIFICANTLY DEFECTIVE IN IL-10 PRODUCTION. OUR DATA SUGGEST THAT, ALTHOUGH STABLY MAINTAINED DNA METHYLATION AT THE PROMOTER MAY REPRESS IL-10 EXPRESSION IN TH1 CELLS, LOCUS-SPECIFIC REVERSIBLE DNA DEMETHYLATION MAY SERVE AS A THRESHOLD PLATFORM TO CONTROL TRANSIENT IL-10 GENE EXPRESSION. 2018 2 1500 40 DNA METHYLATION ANALYSIS OF CD4+ T CELLS IN PATIENTS WITH PSORIASIS. PSORIASIS IS A CHRONIC INFLAMMATORY SKIN DISEASE THAT IS CHARACTERIZED BY ABERRANT CROSS-TALK BETWEEN KERATINOCYTES AND IMMUNE CELLS SUCH AS CD4+ T CELLS, RESULTING IN KERATINOCYTE HYPERPROLIFERATION IN THE EPIDERMIS. DNA METHYLATION, ONE OF SEVERAL EPIGENETIC MECHANISMS, PLAYS AN IMPORTANT ROLE IN GENE EXPRESSION WITHOUT CHANGING THE DNA SEQUENCE. SEVERAL STUDIES HAVE SUGGESTED THE INVOLVEMENT OF EPIGENETIC REGULATION IN SKIN LESIONS FROM PATIENTS WITH PSORIASIS. IN THIS STUDY, WE INVESTIGATED THE GENOME-WIDE DNA METHYLATION STATUS OF CD4+ T CELLS IN PATIENTS WITH PSORIASIS COMPARED WITH HEALTHY SUBJECTS USING METHYLATED DNA IMMUNOPRECIPITATION SEQUENCING (MEDIP-SEQ). THE RESULTS OF MEDIP-SEQ SHOWED THAT THE GLOBAL METHYLATION VALUES OF CD4+ T CELLS ARE HIGHER IN PATIENTS WITH PSORIASIS THAN IN HEALTHY CONTROLS, PARTICULARLY IN THE PROMOTER REGIONS. AMONG THE MOST HYPERMETHYLATED GENES IN THE PROMOTER REGIONS, WE SELECTED THE GENES WHOSE EXPRESSION IS SIGNIFICANTLY REDUCED IN THE CD4+ T CELLS OF PSORIASIS PATIENTS. STUDIES USING THE METHYLATION INHIBITOR 5-AZACYTIDINE IN VITRO METHYLATION ASSAYS HAVE SHOWN THAT THE DIFFERENTIAL EXPRESSION LEVELS WERE ASSOCIATED WITH THE METHYLATION STATUS OF EACH GENE. BISULFITE SEQUENCING OF THE TRANSCRIPTION START REGION OF PHOSPHATIDIC ACID PHOSPHATASE TYPE 2 DOMAIN CONTAINING 3 (PPAPDC3), ONE OF THE SELECTED GENES, SHOWED HYPERMETHYLATION IN THE CD4+ T CELLS OF PSORIASIS PATIENTS. THESE RESULTS SUGGESTED THAT THE METHYLATION STATUS, WHICH IS IDENTIFIED BY MEDIP-SEQ OF THE GENES, WAS CORRELATED WITH THE MRNA EXPRESSION LEVEL OF THE GENES. COLLECTIVELY, THE DNA METHYLATION STATUS IN CD4+ T CELLS MIGHT BE ASSOCIATED WITH THE PATHOGENESIS OF PSORIASIS. 2014 3 3523 37 IL-10-PRODUCING B CELLS ARE CHARACTERIZED BY A SPECIFIC METHYLATION SIGNATURE. AMONG THE FAMILY OF REGULATORY B CELLS, THE SUBSET ABLE TO PRODUCE INTERLEUKIN-10 (IL-10) IS THE MOST STUDIED, YET ITS BIOLOGY IS STILL A MATTER OF INVESTIGATION. THE DNA METHYLATION PROFILING OF THE IL-10 GENE LOCUS REVEALED A NOVEL EPIGENETIC SIGNATURE CHARACTERIZING MURINE B CELLS READY TO RESPOND THROUGH IL-10 SYNTHESIS: A DEMETHYLATED REGION LOCATED 4.5 KB FROM THE TRANSCRIPTION STARTING SITE (TSS), THAT WE NAMED EARLY IL10 REGULATORY REGION (EIL10RR). THIS FEATURE ALLOWS TO DISTINGUISH B CELLS THAT ARE IMMEDIATELY PRONE AND DEVELOPMENTALLY COMMITTED TO IL-10 PRODUCTION FROM THOSE THAT REQUIRE A PERSISTENT STIMULATION TO EXERT AN IL-10-MEDIATED REGULATORY FUNCTION. THESE LATE IL-10 PRODUCERS ARE INSTEAD CHARACTERIZED BY A DELAYED IL10 REGULATORY REGION (DIL10RR), A PARTIALLY DEMETHYLATED DNA PORTION LOCATED 9 KB UPSTREAM FROM THE TSS. A DEMETHYLATED REGION WAS ALSO FOUND IN HUMAN IL-10-PRODUCING B CELLS AND, VERY INTERESTINGLY, IN SOME B-CELL MALIGNANCIES, SUCH AS CHRONIC LYMPHOCYTIC LEUKEMIA AND MANTLE CELL LYMPHOMA, CHARACTERIZED BY AN IMMUNOSUPPRESSIVE MICROENVIRONMENT. OUR FINDINGS DEFINE MURINE AND HUMAN REGULATORY B CELLS AS AN EPIGENETICALLY CONTROLLED FUNCTIONAL STATE OF MATURE B CELL SUBSETS AND OPEN A NEW PERSPECTIVE ON IL-10 REGULATION IN B CELLS IN HOMEOSTASIS AND DISEASE. 2019 4 1566 40 DNA METHYLATION OF TH1/TH2 CYTOKINE GENES AFFECTS SENSITIZATION AND PROGRESS OF EXPERIMENTAL ASTHMA. BACKGROUND: EPIGENETIC CHANGES IN DNA METHYLATION HAVE RECENTLY BEEN DEMONSTRATED TO BE INVOLVED IN EFFECTOR T-CELL POLARIZATION, RESULTING IN DIFFERENTIAL SECRETION OF T(H)1 AND T(H)2 CYTOKINES. HOWEVER, THE CONTRIBUTION TO THE DEVELOPMENT OF A CHRONIC INFLAMMATORY PHENOTYPE REMAINS STILL UNCLEAR. OBJECTIVE: WE SOUGHT TO INVESTIGATE CHANGES IN DNA METHYLATION IN MARKER GENES OF T-CELL SUBSETS DURING ALLERGEN SENSITIZATION/CHALLENGE AND THEIR INFLUENCE ON THE DEVELOPMENT OF AN ALLERGIC AIRWAY INFLAMMATORY RESPONSE. METHODS: THE RELATIONSHIP BETWEEN CHANGES IN DNA METHYLATION AND PHENOTYPE DEVELOPMENT WERE EXAMINED IN A WELL-ESTABLISHED MODEL OF EXPERIMENTAL ASTHMA. DNA METHYLATION WAS INVESTIGATED AT GENOMIC LOCI ASSOCIATED WITH T(H)1 (IFNG PROMOTER) OR T(H)2 (CONSERVED NONCODING SEQUENCE 1 [CNS1]) CYTOKINE PRODUCTION BY USING BISULFITE PYROSEQUENCING. RESULTS: ANALYSIS OF CD4(+) T CELLS REVEALED A SIGNIFICANT INCREASE IN DNA METHYLATION AT THE IFNG PROMOTER AFTER ALLERGEN SENSITIZATION/CHALLENGE, WHICH CORRELATED WITH DECREASED IFN-GAMMA CYTOKINE EXPRESSION, WHEREAS ONLY MINOR CHANGES WERE OBSERVED AT THE CNS1 LOCUS. FURTHERMORE, THE INCREASE IN DNA METHYLATION AT THE IFNG PROMOTER COULD BE REVERSED WITH A DNA METHYLTRANSFERASE (DNMT) INHIBITOR IN VITRO AND IN VIVO WITH BENEFICIAL EFFECTS ON SENSITIZATION STATUS AND ALLERGIC PHENOTYPE. THE SPECIFIC IMPORTANCE OF THE DNA METHYLATION STATUS IN CD4(+) T CELLS COULD BE CONFIRMED BY USING ADOPTIVE TRANSFER EXPERIMENTS. CONCLUSION: WE HERE REPORT THE NOVEL FINDING THAT EPIGENETIC REGULATION IN T CELLS CONTRIBUTES TO THE DEVELOPMENT OF EXPERIMENTAL ASTHMA AND CAN BE TARGETED PHARMACOLOGICALLY. 2012 5 3422 37 HUMAN MONOCYTE-TO-MACROPHAGE DIFFERENTIATION INVOLVES HIGHLY LOCALIZED GAIN AND LOSS OF DNA METHYLATION AT TRANSCRIPTION FACTOR BINDING SITES. BACKGROUND: MACROPHAGES AND THEIR PRECURSORS MONOCYTES PLAY A KEY ROLE IN INFLAMMATION AND CHRONIC INFLAMMATORY DISORDERS. MONOCYTE-TO-MACROPHAGE DIFFERENTIATION AND ACTIVATION PROGRAMS ARE ACCOMPANIED BY SIGNIFICANT EPIGENETIC REMODELING WHERE DNA METHYLATION ASSOCIATES WITH CELL IDENTITY. HERE WE SHOW THAT DNA METHYLATION CHANGES CHARACTERISTIC FOR MONOCYTE-TO-MACROPHAGE DIFFERENTIATION OCCUR AT TRANSCRIPTION FACTOR BINDING SITES, AND, IN CONTRAST TO WHAT WAS PREVIOUSLY DESCRIBED, ARE GENERALLY HIGHLY LOCALIZED AND ENCOMPASS BOTH LOSSES AND GAINS OF DNA METHYLATION. RESULTS: WE COMPARED GENOME-WIDE DNA METHYLATION ACROSS 440,292 CPG SITES BETWEEN HUMAN MONOCYTES, NAIVE MACROPHAGES AND MACROPHAGES FURTHER ACTIVATED TOWARD A PRO-INFLAMMATORY STATE (USING LPS/IFNGAMMA), AN ANTI-INFLAMMATORY STATE (IL-4) OR FOAM CELLS (OXLDL AND ACLDL). MOREOVER, WE INTEGRATED THESE DATA WITH PUBLIC WHOLE-GENOME SEQUENCING DATA ON MONOCYTES AND MACROPHAGES TO DEMARCATE DIFFERENTIALLY METHYLATED REGIONS. OUR ANALYSIS SHOWED THAT DIFFERENTIAL DNA METHYLATION WAS MOST PRONOUNCED DURING MONOCYTE-TO-MACROPHAGE DIFFERENTIATION, WAS TYPICALLY RESTRICTED TO SINGLE CPGS OR VERY SHORT REGIONS, AND CO-LOCALIZED WITH LINEAGE-SPECIFIC ENHANCERS IRRESPECTIVE OF WHETHER IT CONCERNS GAIN OR LOSS OF METHYLATION. FURTHERMORE, DIFFERENTIALLY METHYLATED CPGS WERE LOCATED AT SITES CHARACTERIZED BY INCREASED BINDING OF TRANSCRIPTION FACTORS KNOWN TO BE INVOLVED IN MONOCYTE-TO-MACROPHAGE DIFFERENTIATION INCLUDING C/EBP AND ETS FOR GAIN AND AP-1 FOR LOSS OF METHYLATION. CONCLUSION: OUR STUDY HIGHLIGHTS THE INVOLVEMENT OF SUBTLE, YET HIGHLY LOCALIZED REMODELING OF DNA METHYLATION AT REGULATORY REGIONS IN CELL DIFFERENTIATION. 2019 6 6293 25 THE PRO- AND ANTI-INFLAMMATORY POTENTIAL OF IL-12: THE DUAL ROLE OF TH1 CELLS. THE DIFFERENTIATION OF T-HELPER (TH) LYMPHOCYTES INTO VARIOUS TYPES OF T-HELPER EFFECTOR AND MEMORY CELLS WITH DISTINCT FUNCTIONS DEPENDING ON THE TYPE OF CONCOMITANT SIGNALS THEY RECEIVE UPON ACTIVATION IS A CRITICAL EVENT DETERMINING THE COURSE OF AN IMMUNE REACTION. TH1 CELLS CHARACTERIZED BY THE EXPRESSION OF IFN-GAMMA AND THE RECENTLY DESCRIBED TH17 CELLS PROMOTE INFLAMMATION AND ARE CRITICALLY INVOLVED IN THE INDUCTION AND MAINTENANCE OF AUTOIMMUNITY, WHEREAS THE SECRETION OF IL-4 IS A HALLMARK OF TH2 CELLS MEDIATING PROTECTION FROM PARASITES AND ALLERGY. ORIGINAL STIMULATION IN THE PRESENCE OF IL-12 RESULTS IN THE IMPRINTING OF TH1 MEMORY CELLS FOR THE EXPRESSION OF IFN-GAMMA BY EXPRESSION OF THE TRANSCRIPTION FACTOR T-BET AND EPIGENETIC MODIFICATION OF THE IFNGAMMA GENE. IT HAS BEEN DEMONSTRATED THAT TH1 CELLS ARE POTENT INDUCERS OF INFLAMMATION. HOWEVER, IN THE CHRONIC PHASE OF SUCH INFLAMMATION, THE REGULATORY POTENTIAL OF IL-12 AND TH1 CELLS THEMSELVES MAY PLAY AN IMPORTANT ROLE IN LIMITING IMMUNOPATHOLOGY. 2007 7 3795 30 INTERLEUKIN-6 CONTRIBUTES TO GROWTH IN CHOLANGIOCARCINOMA CELLS BY ABERRANT PROMOTER METHYLATION AND GENE EXPRESSION. THE ASSOCIATION BETWEEN CHRONIC INFLAMMATION AND THE DEVELOPMENT AND PROGRESSION OF MALIGNANCY IS EXEMPLIFIED IN THE BILIARY TRACT WHERE PERSISTENT INFLAMMATION STRONGLY PREDISPOSES TO CHOLANGIOCARCINOMA. THE INFLAMMATORY CYTOKINE INTERLEUKIN-6 (IL-6) ENHANCES TUMOR GROWTH IN CHOLANGIOCARCINOMA BY ALTERED GENE EXPRESSION VIA AUTOCRINE MECHANISMS. IL-6 CAN REGULATE THE ACTIVITY OF DNA METHYLTRANSFERASES, AND MOREOVER, ABERRANT DNA METHYLATION CAN CONTRIBUTE TO CARCINOGENESIS. WE THEREFORE INVESTIGATED THE EFFECT OF CHRONIC EXPOSURE TO IL-6 ON METHYLATION-DEPENDENT GENE EXPRESSION AND TRANSFORMED CELL GROWTH IN HUMAN CHOLANGIOCARCINOMA. THE RELATIONSHIP BETWEEN AUTOCRINE IL-6 PATHWAYS, DNA METHYLATION, AND TRANSFORMED CELL GROWTH WAS ASSESSED USING MALIGNANT CHOLANGIOCYTES STABLY TRANSFECTED TO OVEREXPRESS IL-6. TREATMENT WITH THE DNA METHYLATION INHIBITOR 5-AZA-2'-DEOXYCYTIDINE DECREASED CELL PROLIFERATION, GROWTH IN SOFT AGAR, AND METHYLCYTOSINE CONTENT OF MALIGNANT CHOLANGIOCYTES. HOWEVER, THIS EFFECT WAS NOT OBSERVED IN IL-6-OVEREXPRESSING CELLS. IL-6 OVEREXPRESSION RESULTED IN THE ALTERED EXPRESSION AND PROMOTER METHYLATION OF SEVERAL GENES, INCLUDING THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR). EGFR PROMOTER METHYLATION WAS DECREASED AND GENE AND PROTEIN EXPRESSION WAS INCREASED BY IL-6. THUS, EPIGENETIC REGULATION OF GENE EXPRESSION BY IL-6 CAN CONTRIBUTE TO TUMOR PROGRESSION BY ALTERING PROMOTER METHYLATION AND GENE EXPRESSION OF GROWTH-REGULATORY PATHWAYS, SUCH AS THOSE INVOLVING EGFR. MOREOVER, ENHANCED IL-6 EXPRESSION MAY DECREASE THE SENSITIVITY OF TUMOR CELLS TO THERAPEUTIC TREATMENTS USING METHYLATION INHIBITORS. THESE OBSERVATIONS HAVE IMPORTANT IMPLICATIONS FOR CANCER TREATMENT AND PROVIDE A MECHANISM BY WHICH PERSISTENT CYTOKINE STIMULATION CAN PROMOTE TUMOR GROWTH. 2006 8 5223 40 PRIMARY MURINE CD4+ T CELLS FAIL TO ACQUIRE THE ABILITY TO PRODUCE EFFECTOR CYTOKINES WHEN ACTIVE RAS IS PRESENT DURING TH1/TH2 DIFFERENTIATION. CONSTITUTIVE RAS SIGNALING HAS BEEN SHOWN TO AUGMENT IL-2 PRODUCTION, REVERSE ANERGY, AND FUNCTIONALLY REPLACE MANY ASPECTS OF CD28 CO-STIMULATION IN CD4+ T CELLS. THESE DATA RAISE THE POSSIBILITY THAT INTRODUCTION OF ACTIVE RAS INTO PRIMARY T CELLS MIGHT RESULT IN IMPROVED FUNCTIONALITY IN PATHOLOGIC SITUATIONS OF T CELL DYSFUNCTION, SUCH AS CANCER OR CHRONIC VIRAL INFECTION. TO TEST THE BIOLOGIC EFFECTS OF ACTIVE RAS IN PRIMARY T CELLS, CD4+ T CELLS FROM COXSACKIE-ADENOVIRUS RECEPTOR TRANSGENIC MICE WERE TRANSDUCED WITH AN ADENOVIRUS ENCODING ACTIVE RAS. AS EXPECTED, ACTIVE RAS AUGMENTED IL-2 PRODUCTION IN NAIVE CD4+ T CELLS. HOWEVER, WHEN CELLS WERE CULTURED FOR 4 DAYS UNDER CONDITIONS TO PROMOTE EFFECTOR CELL DIFFERENTIATION, ACTIVE RAS INHIBITED THE ABILITY OF CD4+ T CELLS TO ACQUIRE A TH1 OR TH2 EFFECTOR CYTOKINE PROFILE. THIS DIFFERENTIATION DEFECT WAS NOT DUE TO DEFICIENT STAT4 OR STAT6 ACTIVATION BY IL-12 OR IL-4, RESPECTIVELY, NOR WAS IT ASSOCIATED WITH DEFICIENT INDUCTION OF T-BET AND GATA-3 EXPRESSION. IMPAIRED EFFECTOR CYTOKINE PRODUCTION IN ACTIVE RAS-TRANSDUCED CELLS WAS ASSOCIATED WITH DEFICIENT DEMETHYLATION OF THE IL-4 GENE LOCUS. OUR RESULTS INDICATE THAT, DESPITE AUGMENTING ACUTE ACTIVATION OF NAIVE T CELLS, CONSTITUTIVE RAS SIGNALING INHIBITS THE ABILITY OF CD4+ T CELLS TO PROPERLY DIFFERENTIATE INTO TH1/TH2 EFFECTOR CYTOKINE-PRODUCING CELLS, IN PART BY INTERFERING WITH EPIGENETIC MODIFICATION OF EFFECTOR GENE LOCI. ALTERNATIVE STRATEGIES TO POTENTIATE RAS PATHWAY SIGNALING IN T CELLS IN A MORE REGULATED FASHION SHOULD BE CONSIDERED AS A THERAPEUTIC APPROACH TO IMPROVE IMMUNE RESPONSES IN VIVO. 2014 9 1479 26 DIVERSE TARGETS OF THE TRANSCRIPTION FACTOR STAT3 CONTRIBUTE TO T CELL PATHOGENICITY AND HOMEOSTASIS. STAT3, AN ESSENTIAL TRANSCRIPTION FACTOR WITH PLEIOTROPIC FUNCTIONS, PLAYS CRITICAL ROLES IN THE PATHOGENESIS OF AUTOIMMUNITY. DESPITE RECENT DATA LINKING STAT3 WITH INFLAMMATORY BOWEL DISEASE, EXACTLY HOW IT CONTRIBUTES TO CHRONIC INTESTINAL INFLAMMATION IS NOT KNOWN. USING A T CELL TRANSFER MODEL OF COLITIS, WE FOUND THAT STAT3 EXPRESSION IN T CELLS WAS ESSENTIAL FOR THE INDUCTION OF BOTH COLITIS AND SYSTEMIC INFLAMMATION. STAT3 WAS CRITICAL IN MODULATING THE BALANCE OF T HELPER 17 (TH17) AND REGULATORY T (TREG) CELLS, AS WELL AS IN PROMOTING CD4(+) T CELL PROLIFERATION. WE USED CHROMATIN IMMUNOPRECIPITATION AND MASSIVE PARALLEL SEQUENCING (CHIP-SEQ) TO DEFINE THE GENOME-WIDE TARGETS OF STAT3 IN CD4(+) T CELLS. WE FOUND THAT STAT3 BOUND TO MULTIPLE GENES INVOLVED IN TH17 CELL DIFFERENTIATION, CELL ACTIVATION, PROLIFERATION, AND SURVIVAL, REGULATING BOTH EXPRESSION AND EPIGENETIC MODIFICATIONS. THUS, STAT3 ORCHESTRATES MULTIPLE CRITICAL ASPECTS OF T CELL FUNCTION IN INFLAMMATION AND HOMEOSTASIS. 2010 10 2392 36 EPIGENETIC REPRESSION OF INTERLEUKIN 2 EXPRESSION IN SENESCENT CD4+ T CELLS DURING CHRONIC HIV TYPE 1 INFECTION. THE MOLECULAR MECHANISMS FOR IL2 GENE-SPECIFIC DYSREGULATION DURING CHRONIC HUMAN IMMUNODEFICIENCY VIRUS TYPE 1 (HIV-1) INFECTION ARE UNKNOWN. HERE, WE INVESTIGATED THE ROLE OF DNA METHYLATION IN SUPPRESSING INTERLEUKIN 2 (IL-2) EXPRESSION IN MEMORY CD4(+) T CELLS DURING CHRONIC HIV-1 INFECTION. WE OBSERVED THAT CPG SITES IN THE IL2 PROMOTER OF CD4(+) T CELLS WERE FULLY METHYLATED IN NAIVE CD4(+) T CELLS AND SIGNIFICANTLY DEMETHYLATED IN THE MEMORY POPULATIONS. INTERESTINGLY, WE FOUND THAT THE MEMORY CELLS THAT HAD A TERMINALLY DIFFERENTIATED PHENOTYPE AND EXPRESSED CD57 HAD INCREASED IL2 PROMOTER METHYLATION RELATIVE TO LESS DIFFERENTIATED MEMORY CELLS IN HEALTHY INDIVIDUALS. IMPORTANTLY, EARLY EFFECTOR MEMORY SUBSETS FROM HIV-1-INFECTED SUBJECTS EXPRESSED HIGH LEVELS OF CD57 AND WERE HIGHLY METHYLATED AT THE IL2 LOCUS. FURTHERMORE, THE INCREASED CD57 EXPRESSION ON MEMORY CD4(+) T CELLS WAS INVERSELY CORRELATED WITH IL-2 PRODUCTION. THESE DATA SUGGEST THAT DNA METHYLATION AT THE IL2 LOCUS IN CD4(+) T CELLS IS COUPLED TO IMMUNOSENESCENCE AND PLAYS A CRITICAL ROLE IN THE BROAD DYSFUNCTION THAT OCCURS IN POLYCLONAL T CELLS DURING HIV-1 INFECTION. 2015 11 141 30 ABERRANT DNA METHYLATION OF MTOR PATHWAY GENES PROMOTES INFLAMMATORY ACTIVATION OF IMMUNE CELLS IN DIABETIC KIDNEY DISEASE. DNA METHYLATION HAS BEEN IMPLICATED IN THE PATHOGENESIS OF DIABETIC KIDNEY DISEASE (DKD), BUT THE UNDERLYING MECHANISMS REMAIN UNCLEAR. IN THIS STUDY, WE TESTED THE HYPOTHESIS THAT ABERRANT DNA METHYLATION IN PERIPHERAL IMMUNE CELLS CONTRIBUTES TO DKD PROGRESSION. WE SHOWED THAT LEVELS OF DNA METHYLTRANSFERASE 1 (DNMT1), A KEY ENZYME FOR DNA METHYLATION, WERE INCREASED ALONG WITH INFLAMMATORY ACTIVITY OF PERIPHERAL BLOOD MONONUCLEAR CELLS IN DKD PATIENTS. INHIBITION OF DNMT1 WITH 5-AZA-2'-DEOXYCYTIDINE (5-AZA) MARKEDLY INCREASED THE PROPORTION OF CD4(+)CD25(+) REGULATORY T CELLS IN PERIPHERAL BLOOD MONONUCLEAR CELLS IN CULTURE AND IN DIABETIC ANIMALS. ADOPTIVE TRANSFER OF IMMUNE CELLS FROM 5-AZA-TREATED ANIMALS SHOWED BENEFICIAL EFFECTS ON THE HOST IMMUNE SYSTEM, RESULTING IN A SIGNIFICANT IMPROVEMENT OF DKD. USING GENOME-WIDE DNA METHYLATION ASSAYS, WE IDENTIFIED THE DIFFERENTIALLY METHYLATED CYTOSINES IN THE PROMOTER REGIONS OF MAMMALIAN TARGET OF RAPAMYCIN (MTOR) REGULATORS IN PERIPHERAL BLOOD MONONUCLEAR CELLS OF DIABETIC PATIENTS. FURTHER, MRNA ARRAYS CONFIRMED THE CONSISTENT INDUCTION OF GENES EXPRESSED IN THE MTOR PATHWAY. IMPORTANTLY, DOWN-REGULATION OF DNMT1 EXPRESSION VIA RNA INTERFERENCE RESULTED IN PROMINENT CYTOSINE DEMETHYLATION OF MTOR NEGATIVE REGULATORS AND SUBSEQUENT DECREASE OF MTOR ACTIVITY. LASTLY, MODULATION OF MTOR RESULTED IN CHANGES IN THE EFFECT OF 5-AZA ON DIABETIC IMMUNE CELLS. THUS, UP-REGULATION OF DNMT1 IN DIABETIC IMMUNE CELLS INDUCES ABERRANT CYTOSINE METHYLATION OF THE UPSTREAM REGULATORS OF MTOR, LEADING TO PATHOGENIC ACTIVATION OF THE MTOR PATHWAY AND CONSEQUENT INFLAMMATION IN DIABETIC KIDNEYS. HENCE, THIS STUDY HIGHLIGHTS THERAPEUTIC POTENTIAL OF TARGETING EPIGENETIC EVENTS IN IMMUNE SYSTEM FOR TREATING DKD. 2019 12 3791 39 INTERLEUKIN 6 SUPPORTS THE MAINTENANCE OF P53 TUMOR SUPPRESSOR GENE PROMOTER METHYLATION. A STRONG ASSOCIATION EXISTS BETWEEN STATES OF CHRONIC INFLAMMATION AND CANCER, AND IT IS BELIEVED THAT MEDIATORS OF INFLAMMATION MAY BE RESPONSIBLE FOR THIS PHENOMENON. INTERLEUKIN 6 (IL-6) IS AN INFLAMMATORY CYTOKINE KNOWN TO PLAY A ROLE IN THE GROWTH AND SURVIVAL OF MANY TYPES OF TUMORS, YET THE MECHANISMS EMPLOYED BY THIS PLEOMORPHIC CYTOKINE TO ACCOMPLISH THIS FEAT ARE STILL POORLY UNDERSTOOD. ANOTHER IMPORTANT FACTOR IN TUMOR DEVELOPMENT SEEMS TO BE THE HYPERMETHYLATION OF CPG ISLANDS LOCATED WITHIN THE PROMOTER REGIONS OF TUMOR SUPPRESSOR GENES. THIS COMMON EPIGENETIC ALTERATION ENABLES TUMOR CELLS TO REDUCE OR INACTIVATE THE EXPRESSION OF IMPORTANT TUMOR SUPPRESSOR AND CELL CYCLE REGULATORY GENES. HERE WE SHOW THAT IN THE IL-6-RESPONSIVE HUMAN MULTIPLE MYELOMA CELL LINE KAS 6/1, THE PROMOTER REGION OF P53 IS EPIGENETICALLY MODIFIED BY METHYLTRANSFERASES, RESULTING IN DECREASED LEVELS OF EXPRESSION. FURTHERMORE, CELLS TREATED WITH IL-6 EXHIBIT AN INCREASE IN THE EXPRESSION OF THE DNA MAINTENANCE METHYLATION ENZYME, DNMT-1. THE DNA METHYLTRANSFERASE INHIBITOR ZEBULARINE REVERSES THE METHYLATION OF THE P53 PROMOTER, ALLOWING THE RESUMPTION OF ITS EXPRESSION. HOWEVER, WHEN ZEBULARINE IS WITHDRAWN FROM THE CELLS, THE REESTABLISHMENT OF THE ORIGINAL CPG ISLAND METHYLATION WITHIN THE P53 PROMOTER DOES NOT OCCUR IN THE ABSENCE OF IL-6, AND CELLS WHICH DO NOT RECEIVE IL-6 EVENTUALLY DIE, AS P53 EXPRESSION CONTINUES UNCHECKED BY REMETHYLATION. INTERESTINGLY, THIS LOSS OF VIABILITY SEEMS TO INVOLVE NOT THE WITHDRAWAL OF CYTOKINE, BUT THE INABILITY OF THE CELL TO RESILENCE THE PROMOTER. CONSISTENT WITH THIS MODEL, WHEN CELLS THAT EXPRESS IL-6 IN AN AUTOCRINE FASHION ARE SUBJECTED TO IDENTICAL TREATMENT, P53 EXPRESSION IS REDUCED SHORTLY AFTER WITHDRAWAL OF ZEBULARINE. THEREFORE, IT SEEMS IL-6 IS CAPABLE OF MAINTAINING PROMOTER METHYLATION THUS REPRESENTING ONE OF THE POSSIBLE MECHANISMS USED BY INFLAMMATORY MEDIATORS IN THE GROWTH AND SURVIVAL OF TUMORS. 2005 13 6661 34 UPREGULATION OF DNA METHYLTRANSFERASE-MEDIATED GENE SILENCING, ANCHORAGE-INDEPENDENT GROWTH, AND MIGRATION OF COLON CANCER CELLS BY INTERLEUKIN-6. INFLAMMATORY BOWEL DISEASE IS CHARACTERIZED BY CHRONIC INFLAMMATION WHICH PREDISPOSES TO COLORECTAL CANCER. THE MECHANISMS BY WHICH INFLAMMATION PROMOTES TUMORIGENESIS ARE NOT FULLY KNOWN. WE AIMED TO INVESTIGATE THE LINKS BETWEEN COLONIC INFLAMMATION AND TUMORIGENESIS VIA EPIGENETIC GENE SILENCING. COLON CANCER SPECIMENS WERE ASSESSED FOR THE EXPRESSION OF DNA METHYLTRANSFERASE-1 (DNMT-1) USING IMMUNOHISTOCHEMISTRY. COLORECTAL CARCINOMA CELL LINES WERE ASSESSED FOR DNMT1 EXPRESSION, METHYLCYTOSINE CONTENT, PROMOTER METHYLATION, GENE EXPRESSION, AND TUMORIGENESIS IN RESPONSE TO INTERLEUKIN (IL)-6. DNMT1 WAS EXPRESSED AT HIGHER LEVELS IN BOTH THE PERITUMORAL STROMA AND TUMOR IN INFLAMMATORY BOWEL DISEASE-ASSOCIATED CANCERS COMPARED WITH SPORADIC COLON CANCERS. IL-6 TREATMENT OF COLON CANCER CELLS RESULTED IN AN INCREASE IN DNMT1 EXPRESSION, INDEPENDENT OF DE NOVO GENE EXPRESSION. IL-6 INCREASED THE METHYLATION OF PROMOTER REGIONS OF GENES ASSOCIATED WITH TUMOR SUPPRESSION, ADHESION, AND APOPTOSIS RESISTANCE. EXPRESSION OF A SUBSET OF THESE GENES WAS DOWNREGULATED BY IL-6, AN EFFECT THAT WAS PREVENTED BY PREINCUBATION WITH 5-AZADEOXYCYTIDINE, A DNMT1 INHIBITOR. ANCHORAGE-INDEPENDENT GROWTH AND MIGRATION OF COLON CANCER CELLS WAS ALSO INCREASED BY IL-6 IN A 5-AZADEOXYCYTIDINE-SENSITIVE MANNER. OUR RESULTS INDICATE THAT DNMT-MEDIATED GENE SILENCING MAY PLAY A ROLE IN INFLAMMATION-ASSOCIATED COLON TUMORIGENESIS. 2010 14 6764 35 ZINC DEFICIENCY ENHANCED INFLAMMATORY RESPONSE BY INCREASING IMMUNE CELL ACTIVATION AND INDUCING IL6 PROMOTER DEMETHYLATION. SCOPE: ZINC DEFICIENCY RESULTS IN IMMUNE DYSFUNCTION AND PROMOTES SYSTEMIC INFLAMMATION. THE OBJECTIVE OF THIS STUDY WAS TO EXAMINE THE EFFECTS OF ZINC DEFICIENCY ON CELLULAR IMMUNE ACTIVATION AND EPIGENETIC MECHANISMS THAT PROMOTE INFLAMMATION. THIS WORK IS POTENTIALLY RELEVANT TO THE AGING POPULATION GIVEN THAT AGE-RELATED IMMUNE DEFECTS, INCLUDING CHRONIC INFLAMMATION, COINCIDE WITH DECLINING ZINC STATUS. METHODS AND RESULTS: AN IN VITRO CELL CULTURE SYSTEM AND THE AGED MOUSE MODEL WERE USED TO CHARACTERIZE IMMUNE ACTIVATION AND DNA METHYLATION PROFILES THAT MAY CONTRIBUTE TO THE ENHANCED PROINFLAMMATORY RESPONSE MEDIATED BY ZINC DEFICIENCY. ZINC DEFICIENCY UPREGULATED CELL ACTIVATION MARKERS ICAM1, MHC CLASS II, AND CD86 IN THP1 CELLS, WHICH COINCIDED WITH INCREASED IL1BETA AND IL6 RESPONSES FOLLOWING LPS STIMULATION. A DECREASED ZINC STATUS IN AGED MICE WAS SIMILARLY ASSOCIATED WITH INCREASED ICAM1 AND IL6 GENE EXPRESSION. REDUCED IL6 PROMOTER METHYLATION WAS OBSERVED IN ZINC-DEFICIENT THP1 CELLS, AS WELL AS IN AGED MICE AND HUMAN LYMPHOBLASTOID CELL LINES DERIVED FROM AGED INDIVIDUALS. CONCLUSION: ZINC DEFICIENCY INDUCED INFLAMMATORY RESPONSE IN PART BY ELICITING ABERRANT IMMUNE CELL ACTIVATION AND ALTERED PROMOTER METHYLATION. OUR RESULTS SUGGESTED POTENTIAL INTERACTIONS BETWEEN ZINC STATUS, EPIGENETICS, AND IMMUNE FUNCTION, AND HOW THEIR DYSREGULATION COULD CONTRIBUTE TO CHRONIC INFLAMMATION. 2015 15 5975 25 TET1 IS AN IMPORTANT TRANSCRIPTIONAL ACTIVATOR OF TNFALPHA EXPRESSION IN MACROPHAGES. ACTIVATION OF MACROPHAGES AND OVEREXPRESSION OF TNFALPHA IS ASSOCIATED WITH THE PATHOGENESIS OF CHRONIC INFLAMMATORY DISEASES. HOWEVER, THE MECHANISMS LEADING TO TNFALPHA OVEREXPRESSION ARE STILL UNKNOWN. 5-METHYLOCYTOSINE (5-MC) IS AN EPIGENETIC MODIFICATION THAT IS ASSOCIATED WITH SILENCED GENES. RECENT STUDIES SHOWED THAT IT IS CONVERTED TO 5-HYDROXYLMETHYLOCYTOSINE (5-HMC) AND REACTIVATES GENE EXPRESSION THROUGH THE ACTION OF THE FAMILY OF TEN-ELEVEN-TRANSLOCATION (TET1-3) ENZYMES. IN THIS STUDY, WE SHOW THAT 5-HMC LEVELS ARE INCREASED GLOBALLY AND SPECIFICALLY IN THE TNFALPHA PROMOTER DURING THE DIFFERENTIATION OF MONOCYTES TO MACROPHAGES. IN ADDITION, THE LEVELS OF 5-HMC ARE INCREASED UPON LPS STIMULATION OF MACROPHAGES. FURTHERMORE, CRIPSR STABLE KNOCKOUT OF TET1 DECREASES THE EXPRESSION OF TNFALPHA AND OTHER PRO-INFLAMMATORY CYTOKINES. IN CONCLUSION, WE SHOWED THAT TET1 CONTRIBUTES TO THE ACTIVATION OF MACROPHAGES POSSIBLY THROUGH REGULATION OF 5-HYDROXYMETHYLATION IN THE PROMOTER OF PRO-INFLAMMATORY CYTOKINE GENES. THE TET1 ENZYME COULD BE A PROMISING THERAPEUTIC TARGET TO INHIBIT THE PERSISTENT INFLAMMATION CAUSED BY MACROPHAGES IN CHRONIC INFLAMMATORY DISEASES. 2019 16 3043 35 GENOME-WIDE ANALYSIS IDENTIFIES NR4A1 AS A KEY MEDIATOR OF T CELL DYSFUNCTION. T CELLS BECOME DYSFUNCTIONAL WHEN THEY ENCOUNTER SELF ANTIGENS OR ARE EXPOSED TO CHRONIC INFECTION OR TO THE TUMOUR MICROENVIRONMENT(1). THE FUNCTION OF T CELLS IS TIGHTLY REGULATED BY A COMBINATIONAL CO-STIMULATORY SIGNAL, AND DOMINANCE OF NEGATIVE CO-STIMULATION RESULTS IN T CELL DYSFUNCTION(2). HOWEVER, THE MOLECULAR MECHANISMS THAT UNDERLIE THIS DYSFUNCTION REMAIN UNCLEAR. HERE, USING AN IN VITRO T CELL TOLERANCE INDUCTION SYSTEM IN MICE, WE CHARACTERIZE GENOME-WIDE EPIGENETIC AND GENE EXPRESSION FEATURES IN TOLERANT T CELLS, AND SHOW THAT THEY ARE DISTINCT FROM EFFECTOR AND REGULATORY T CELLS. NOTABLY, THE TRANSCRIPTION FACTOR NR4A1 IS STABLY EXPRESSED AT HIGH LEVELS IN TOLERANT T CELLS. OVEREXPRESSION OF NR4A1 INHIBITS EFFECTOR T CELL DIFFERENTIATION, WHEREAS DELETION OF NR4A1 OVERCOMES T CELL TOLERANCE AND EXAGGERATES EFFECTOR FUNCTION, AS WELL AS ENHANCING IMMUNITY AGAINST TUMOUR AND CHRONIC VIRUS. MECHANISTICALLY, NR4A1 IS PREFERENTIALLY RECRUITED TO BINDING SITES OF THE TRANSCRIPTION FACTOR AP-1, WHERE IT REPRESSES EFFECTOR-GENE EXPRESSION BY INHIBITING AP-1 FUNCTION. NR4A1 BINDING ALSO PROMOTES ACETYLATION OF HISTONE 3 AT LYSINE 27 (H3K27AC), LEADING TO ACTIVATION OF TOLERANCE-RELATED GENES. THIS STUDY THUS IDENTIFIES NR4A1 AS A KEY GENERAL REGULATOR IN THE INDUCTION OF T CELL DYSFUNCTION, AND A POTENTIAL TARGET FOR TUMOUR IMMUNOTHERAPY. 2019 17 556 40 AZACYTIDINE TREATMENT INHIBITS THE PROGRESSION OF HERPES STROMAL KERATITIS BY ENHANCING REGULATORY T CELL FUNCTION. OCULAR INFECTION WITH HERPES SIMPLEX VIRUS 1 (HSV-1) SETS OFF AN INFLAMMATORY REACTION IN THE CORNEA WHICH LEADS TO BOTH VIRUS CLEARANCE AND CHRONIC LESIONS THAT ARE ORCHESTRATED BY CD4 T CELLS. APPROACHES THAT ENHANCE THE FUNCTION OF REGULATORY T CELLS (TREG) AND DAMPEN EFFECTOR T CELLS CAN BE EFFECTIVE TO LIMIT STROMAL KERATITIS (SK) LESION SEVERITY. IN THIS REPORT, WE EXPLORE THE NOVEL APPROACH OF INHIBITING DNA METHYLTRANSFERASE ACTIVITY USING 5-AZACYTIDINE (AZA; A CYTOSINE ANALOG) TO LIMIT HSV-1-INDUCED OCULAR LESIONS. WE SHOW THAT THERAPY BEGUN AFTER INFECTION WHEN VIRUS WAS NO LONGER ACTIVELY REPLICATING RESULTED IN A PRONOUNCED REDUCTION IN LESION SEVERITY, WITH MARKEDLY DIMINISHED NUMBERS OF T CELLS AND NONLYMPHOID INFLAMMATORY CELLS, ALONG WITH REDUCED CYTOKINE MEDIATORS. THE REMAINING INFLAMMATORY REACTIONS HAD A CHANGE IN THE RATIO OF CD4 FOXP3(+) TREG TO EFFECTOR TH1 CD4 T CELLS IN OCULAR LESIONS AND LYMPHOID TISSUES, WITH TREG BECOMING PREDOMINANT OVER THE EFFECTORS. IN ADDITION, COMPARED TO THOSE FROM CONTROL MICE, TREG FROM AZA-TREATED MICE SHOWED MORE SUPPRESSOR ACTIVITY IN VITRO AND EXPRESSED HIGHER LEVELS OF ACTIVATION MOLECULES. ADDITIONALLY, CELLS INDUCED IN VITRO IN THE PRESENCE OF AZA SHOWED EPIGENETIC DIFFERENCES IN THE TREG-SPECIFIC DEMETHYLATED REGION (TSDR) OF FOXP3 AND WERE MORE STABLE WHEN EXPOSED TO INFLAMMATORY CYTOKINES. OUR RESULTS SHOW THAT THERAPY WITH AZA IS AN EFFECTIVE MEANS OF CONTROLLING A VIRUS-INDUCED INFLAMMATORY REACTION AND MAY ACT MAINLY BY THE EFFECTS ON TREG.IMPORTANCE HSV-1 INFECTION HAS BEEN SHOWN TO INITIATE AN INFLAMMATORY REACTION IN THE CORNEA THAT LEADS TO TISSUE DAMAGE AND LOSS OF VISION. THE INFLAMMATORY REACTION IS ORCHESTRATED BY GAMMA INTERFERON (IFN-GAMMA)-SECRETING TH1 CELLS, AND REGULATORY T CELLS PLAY A PROTECTIVE ROLE. HENCE, NOVEL THERAPEUTICS THAT CAN REBALANCE THE RATIO OF REGULATORY T CELLS TO EFFECTORS ARE A RELEVANT ISSUE. THIS STUDY OPENS UP A NEW AVENUE IN TREATING HSV-INDUCED SK LESIONS BY INCREASING THE STABILITY AND FUNCTION OF REGULATORY T CELLS USING THE DNA METHYLTRANSFERASE INHIBITOR 5-AZACYTIDINE (AZA). AZA INCREASED THE FUNCTION OF REGULATORY T CELLS, LEADING TO ENHANCED SUPPRESSIVE ACTIVITY AND DIMINISHED LESIONS. HENCE, THERAPY WITH AZA, WHICH ACTS MAINLY BY ITS EFFECTS ON TREG, CAN BE AN EFFECTIVE MEANS TO CONTROL VIRUS-INDUCED INFLAMMATORY LESIONS. 2017 18 5058 37 PHENOTYPIC ALTERATION OF CD8+ T CELLS IN CHRONIC LYMPHOCYTIC LEUKEMIA IS ASSOCIATED WITH EPIGENETIC REPROGRAMMING. IMMUNOSUPPRESSION IS A PREVALENT CLINICAL FEATURE IN CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) PATIENTS, WITH MANY PATIENTS DEMONSTRATING INCREASED SUSCEPTIBILITY TO INFECTIONS AS WELL AS INCREASED FAILURE OF AN ANTITUMOR IMMUNE RESPONSE. HOWEVER, MUCH IS CURRENTLY NOT UNDERSTOOD REGARDING THE PRECISE MECHANISMS THAT ATTRIBUTE TO THIS IMMUNOSUPPRESSIVE PHENOTYPE IN CLL. TO PROVIDE FURTHER CLARITY TO THIS PARTICULAR PHENOMENON, WE ANALYZED THE T-CELL PROFILE OF CLL PATIENT SAMPLES WITHIN A LARGE COHORT AND OBSERVED THAT PATIENTS WITH AN INVERTED CD4/CD8 RATIO HAD A SHORTER TIME TO FIRST TREATMENT AS WELL AS OVERALL SURVIVAL. THESE OBSERVATIONS COINCIDED WITH HIGHER EXPRESSION OF THE IMMUNE CHECKPOINT RECEPTOR PD-1 IN CLL PATIENT CD8+ T CELLS WHEN COMPARED TO AGE-MATCHED HEALTHY DONORS. INTERESTINGLY, WE DISCOVERED THAT INCREASED PD-1 EXPRESSION IN CD8+ T CELLS CORRESPONDS WITH DECREASED DNA METHYLATION LEVELS IN A DISTAL UPSTREAM LOCUS OF THE PD-1 GENE PDCD1. FURTHER ANALYSIS USING LUCIFERASE REPORTER ASSAYS SUGGESTS THAT THE IDENTIFIED PDCD1 DISTAL UPSTREAM REGION ACTS AS AN ENHANCER FOR PDCD1 TRANSCRIPTION AND THIS REGION BECOMES DEMETHYLATED DURING ACTIVATION OF NAIVE CD8+ T CELLS BY ANTI-CD3/ANTI-CD28 ANTIBODIES AND IL2. FINALLY, WE CONDUCTED A GENOME-WIDE DNA METHYLATION ANALYSIS COMPARING CD8+ T CELLS FROM CLL PATIENTS AGAINST HEALTHY DONORS AND IDENTIFIED ADDITIONAL DIFFERENTIALLY METHYLATED GENES WITH KNOWN IMMUNE REGULATORY FUNCTIONS INCLUDING CCR6 AND KLRG1. TAKEN TOGETHER, OUR FINDINGS REVEAL THE OCCURRENCE OF EPIGENETIC REPROGRAMMING TAKING PLACE WITHIN CLL PATIENT CD8+ T CELLS AND HIGHLIGHT THE POTENTIAL MECHANISM OF HOW IMMUNOSUPPRESSION IS ACCOMPLISHED IN CLL. 2016 19 1215 44 CPG PROMOTER METHYLATION STATUS IS NOT A PROGNOSTIC INDICATOR OF GENE EXPRESSION IN BERYLLIUM CHALLENGE. INDIVIDUALS EXPOSED TO BERYLLIUM (BE) MAY DEVELOP BE SENSITIZATION (BES) AND PROGRESS TO CHRONIC BERYLLIUM DISEASE (CBD). RECENT STUDIES WITH OTHER METAL ANTIGENS SUGGEST EPIGENETIC MECHANISMS MAY BE INVOLVED IN INFLAMMATORY DISEASE PROCESSES, INCLUDING GRANULOMATOUS LUNG DISORDERS AND THAT A NUMBER OF METAL CATIONS ALTER GENE METHYLATION. THE OBJECTIVE OF THIS STUDY WAS TO DETERMINE IF BE CAN EXERT AN EPIGENETIC EFFECT ON GENE EXPRESSION BY ALTERING METHYLATION IN THE PROMOTER REGION OF SPECIFIC GENES KNOWN TO BE INVOLVED IN BE ANTIGEN-MEDIATED GENE EXPRESSION. TO INVESTIGATE THIS OBJECTIVE, THREE MACROPHAGE TUMOR MOUSE CELL LINES KNOWN TO DIFFERENTIALLY PRODUCE TUMOR NECROSIS FACTOR (TNF)-ALPHA, BUT NOT INTERFERON (IFN)-GAMMA, IN RESPONSE TO BE ANTIGEN WERE CULTURED WITH BE OR CONTROLS. FOLLOWING CHALLENGES, ELISA WERE PERFORMED TO QUANTIFY INDUCED TNFALPHA AND IFNGAMMA EXPRESSION. BISULFATE-CONVERTED DNA WAS EVALUATED BY PYROSEQUENCING TO QUANTIFY CPG METHYLATION WITHIN THE PROMOTERS OF TNFALPHA AND IFNGAMMA. BE-CHALLENGED H36.12J CELLS EXPRESSED HIGHER LEVELS OF TNFALPHA COMPARED TO EITHER H36.12E CELLS OR P388D.1 CELLS. HOWEVER, THERE WERE NO VARIATIONS IN TNFALPHA PROMOTER CPG METHYLATION LEVELS BETWEEN CELL LINES AT THE SIX CPG SITES TESTED. H36.12J CELL TNFALPHA EXPRESSION WAS SHOWN TO BE METAL-SPECIFIC BY THE INDUCTION OF SIGNIFICANTLY MORE TNFALPHA WHEN EXPOSED TO BE THAN WHEN EXPOSED TO ALUMINUM SULFATE, OR NICKEL (II) CHLORIDE, BUT NOT WHEN EXPOSED TO COBALT (II) CHLORIDE. HOWEVER, H36.12J CELL METHYLATION LEVELS AT THE SIX CPG SITES EXAMINED IN THE TNFALPHA PROMOTER DID NOT CORRELATE WITH CYTOKINE EXPRESSION DIFFERENCES. NONETHELESS, ALL THREE CELL LINES HAD SIGNIFICANTLY MORE PROMOTER METHYLATION AT THE SIX CPG SITES INVESTIGATED WITHIN THE IFNGAMMA PROMOTER (A GENE THAT IS NOT EXPRESSED) WHEN COMPARED TO THE SIX CPG SITES INVESTIGATED IN THE TNFALPHA PROMOTER, REGARDLESS OF TREATMENT CONDITION (P < 1.17 X 10(-9)). THESE FINDINGS SUGGEST THAT, IN THIS CELL SYSTEM, PROMOTER HYPO-METHYLATION MAY BE NECESSARY TO ALLOW EXPRESSION OF METAL-INDUCED TNFALPHA AND THAT PROMOTER HYPER-METHYLATION IN THE IFNGAMMA PROMOTER MAY INTERFERE WITH EXPRESSION. ALSO, AT THE DOZEN CPG SITES INVESTIGATED IN THE PROMOTER REGIONS OF BOTH GENES, BERYLLIUM HAD NO IMPACT ON PROMOTER METHYLATION STATUS, DESPITE ITS ABILITY TO INDUCE PRO-INFLAMMATORY CYTOKINE EXPRESSION. 2016 20 2747 36 EXPRESSION ANALYSIS OF THE EPIGENETIC METHYLTRANSFERASES AND METHYL-CPG BINDING PROTEIN FAMILIES IN THE NORMAL B-CELL AND B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). THE IMPORTANCE OF EPIGENETIC MODIFICATIONS IN CARCINOGENESIS HAS BEEN A SOURCE OF CONTROVERSY FOR SOME TIME. THERE IS LITTLE DOUBT THAT CHANGES IN GENOMIC HYPERMETHYLATION CONTRIBUTE TO THE SILENCING OF TUMOR SUPPRESSOR GENES. FURTHERMORE, RECENT STUDIES HAVE ALSO IDENTIFIED THE SIGNIFICANCE OF GENOMIC HYPOMETHYLATION ASSOCIATED WITH CHROMOSOMAL INSTABILITY AND TUMORIGENESIS. ONE OF THE MOST PERPLEXING QUESTIONS REGARDING EPIGENETIC MODIFICATIONS AND LEUKEMOGENESIS IS THE RELATIONSHIP WITH DNA METHYLTRANSFERASES (DNMT'S). THE PRIMARY FUNCTION OF THE DNMT ENZYMES IS TO METHYLATE GENOMIC DNA, WHEREAS THE METHYL-CPG BINDING DOMAIN PROTEINS (MBD) INTERPRET THIS METHYLATION SIGNAL AND REGULATE GENE EXPRESSION AND CHROMATIN BEHAVIOR. IN THIS STUDY WE ANALYSE THESE GENE FAMILIES BY QUANTITATIVE REAL-TIME PCR TO INVESTIGATE WHETHER EXPRESSION LEVELS AND THE B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA (B-CLL) PHENOTYPE ARE ASSOCIATED. FURTHERMORE, GIVEN THE EPIGENETIC CROSSTALK BETWEEN GENOME STABILITY AND THE HISTONE CHROMATIN CODE WE HAVE ANALYSED EUKARYOTIC HISTONE METHYLTRANSFERASE (EU-HMTASEI). SURPRISINGLY, WE DID NOT OBSERVE SIGNIFICANT CHANGES IN DNMT1 EXPRESSION IN B-CLL CASES WHEN COMPARED TO NORMAL LYMPHOCYTES, REGARDLESS OF WHETHER WE NORMALISE AGAINST GAPDH OR PCNA AS REFERENCE STANDARDS. INDEED, EXPRESSION OF THE MAINTENANCE AND DE NOVO METHYLASES WERE INDEPENDENTLY REGULATED. OF PARTICULAR NOTE WAS THE SIGNIFICANT DOWN REGULATION OF DNMT3B. FURTHERMORE, WE OBSERVED A POSITIVE CORRELATION BETWEEN HMTASEI EXPRESSION LEVELS AND STAGE OF LEUKEMIA SUGGESTING THAT CHANGES IN THE METHYLATION PATTERNS IN B-CLL MAY REPRESENT DEREGULATION OF THE EPIGENETIC REPERTOIRE THAT ALSO INCLUDE THE METHYLATION DEPENDENT BINDING PROTEINS, MBD2 AND MECP2. WE ENVISAGE CHANGES IN THE EPIGENETIC PROGRAM ARE MULTIFACTORIAL IN NATURE AND POSTULATE THAT THE PREVALENT GENOMIC METHYLASES JUST ONE COMPONENT OF A LARGER EPIGENETIC REPERTOIRE. 2004