1 6071 140 THE DNA METHYLATION INHIBITOR 5-AZACYTIDINE INCREASES REGULATORY T CELLS AND ALLEVIATES AIRWAY INFLAMMATION IN OVALBUMIN-SENSITIZED MICE. BACKGROUND: ASTHMA IS CHARACTERIZED AS A CHRONIC INFLAMMATORY DISORDER OF THE AIRWAYS ASSOCIATED WITH AN ENHANCED TH2 RESPONSE TO INHALED ALLERGENS. CD4+ T REGULATORY (TREG) CELLS ARE CONTROLLED BY THE MASTER TRANSCRIPTION FACTOR FOXP3 AND STRICTLY MAINTAIN PERIPHERAL IMMUNOTOLERANCE. EPIGENETIC REGULATION OF FOXP3 BY DNA METHYLTRANSFERASE INHIBITORS, SUCH AS 5-AZACYTIDINE (AZA), CAN GENERATE A STEADY SUPPLY OF FUNCTIONAL TREG CELLS. THEREFORE, WE PROPOSE THAT AZA CAN AUGMENT TREG CELLS IN VIVO TO PREVENT THE PATHOGENESIS OF ASTHMA. METHODS: BALB/C MICE WERE SENSITIZED WITH CHICKEN OVALBUMIN (OVA) AND TREATED WITH DIFFERENT DOSES OF AZA. AIRWAY HYPERRESPONSIVENESS TO METHACHOLINE, EOSINOPHILIA IN BRONCHOALVEOLAR LAVAGE FLUID, CIRCULATING TITERS OF OVA-SPECIFIC IGG1 AND IGE, AND STIMULATING LEVELS OF TH2 CYTOKINES FROM SPLENOCYTES WERE THEN DETERMINED. CELLULAR POPULATIONS WERE EXAMINED BY FLOW CYTOMETRY. PC61 ANTIBODY, WHICH DEPLETES CD25+ CELLS, WAS USED TO VERIFY THE ROLE OF CD25+ CELLS IN AZA-INDUCED TOLERANCE. RESULTS: ADMINISTRATION OF AZA TO OVA-SENSITIZED MICE DIMINISHED AIRWAY HYPERREACTIVITY, PULMONARY EOSINOPHILIA, LEVELS OF OVA-SPECIFIC IGG1 AND IGE IN SERUM, AND SECRETION OF TH2 CYTOKINES FROM OVA-STIMULATED SPLENOCYTES IN A DOSE-DEPENDENT MANNER. PERCENTAGES OF CD25+ AND FOXP3+ CELLS IN THE CD4+ CELL POPULATION WERE NOTABLY INCREASED IN AZA-TREATED MICE COMPARED TO SENSITIZED CONTROL MICE. FURTHERMORE, THE MAJOR SYMPTOMS OF ASTHMA WERE EXACERBATED BY DEPLETING CD25+ CELLS IN AZA-TREATED MICE. CONCLUSIONS: AZA MAY HAVE APPLICATIONS AS A NOVEL CLINICAL STRATEGY TO INCREASE THE PRODUCTION OF TREG CELLS IN ORDER TO MODULATE THE AIRWAY INFLAMMATION ASSOCIATED WITH ASTHMA. 2013 2 3662 41 INDUCTION OF STABLE HUMAN FOXP3(+) TREGS BY A PARASITE-DERIVED TGF-BETA MIMIC. IMMUNE HOMEOSTASIS IN THE INTESTINE IS TIGHTLY CONTROLLED BY FOXP3(+) REGULATORY T CELLS (TREGS), DEFECTS OF WHICH ARE LINKED TO THE DEVELOPMENT OF CHRONIC CONDITIONS, SUCH AS INFLAMMATORY BOWEL DISEASE (IBD). AS A MECHANISM OF IMMUNE EVASION, SEVERAL SPECIES OF INTESTINAL PARASITES BOOST TREG ACTIVITY. THE PARASITE HELIGMOSOMOIDES POLYGYRUS IS KNOWN TO SECRETE A MOLECULE (HP-TGM) THAT MIMICS THE ABILITY OF TGF-BETA TO INDUCE FOXP3 EXPRESSION IN CD4(+) T CELLS. THE STUDY AIMED TO INVESTIGATE WHETHER HP-TGM COULD INDUCE HUMAN FOXP3(+) TREGS AS A POTENTIAL THERAPEUTIC APPROACH FOR INFLAMMATORY DISEASES. CD4(+) T CELLS FROM HEALTHY VOLUNTEERS WERE EXPANDED IN THE PRESENCE OF HP-TGM OR TGF-BETA. TREG INDUCTION WAS MEASURED BY FLOW CYTOMETRIC DETECTION OF FOXP3 AND OTHER TREG MARKERS, SUCH AS CD25 AND CTLA-4. EPIGENETIC CHANGES WERE DETECTED USING CHIP-SEQ AND PYROSEQUENCING OF FOXP3. TREG PHENOTYPE STABILITY WAS ASSESSED FOLLOWING INFLAMMATORY CYTOKINE CHALLENGE AND TREG FUNCTION WAS EVALUATED BY CELLULAR CO-CULTURE SUPPRESSION ASSAYS AND CYTOMETRIC BEAD ARRAYS FOR SECRETED CYTOKINES. HP-TGM EFFICIENTLY INDUCED FOXP3 EXPRESSION (> 60%), IN ADDITION TO CD25 AND CTLA-4, AND CAUSED EPIGENETIC MODIFICATION OF THE FOXP3 LOCUS TO A GREATER EXTENT THAN TGF-BETA. HP-TGM-INDUCED TREGS HAD SUPERIOR SUPPRESSIVE FUNCTION COMPARED WITH TGF-BETA-INDUCED TREGS, AND RETAINED THEIR PHENOTYPE FOLLOWING EXPOSURE TO INFLAMMATORY CYTOKINES. FURTHERMORE, HP-TGM INDUCED A TREG-LIKE PHENOTYPE IN IN VIVO DIFFERENTIATED TH1 AND TH17 CELLS, INDICATING ITS POTENTIAL TO RE-PROGRAM MEMORY CELLS TO ENHANCE IMMUNE TOLERANCE. THESE DATA INDICATE HP-TGM HAS POTENTIAL TO BE USED TO GENERATE STABLE HUMAN FOXP3(+) TREGS TO TREAT IBD AND OTHER INFLAMMATORY DISEASES. 2021 3 407 31 ANALYSIS OF FOXP3+ REGULATORY T CELLS THAT DISPLAY APPARENT VIRAL ANTIGEN SPECIFICITY DURING CHRONIC HEPATITIS C VIRUS INFECTION. WE REPORTED PREVIOUSLY THAT A PROPORTION OF NATURAL CD25(+) CELLS ISOLATED FROM THE PBMC OF HCV PATIENTS CAN FURTHER UPREGULATE CD25 EXPRESSION IN RESPONSE TO HCV PEPTIDE STIMULATION IN VITRO, AND PROPOSED THAT VIRUS-SPECIFIC REGULATORY T CELLS (TREG) WERE PRIMED AND EXPANDED DURING THE DISEASE. HERE WE DESCRIBE EPIGENETIC ANALYSIS OF THE FOXP3 LOCUS IN HCV-RESPONSIVE NATURAL CD25(+) CELLS AND SHOW THAT THESE CELLS ARE NOT ACTIVATED CONVENTIONAL T CELLS EXPRESSING FOXP3, BUT HARD-WIRED TREG WITH A STABLE FOXP3 PHENOTYPE AND FUNCTION. OF APPROXIMATELY 46,000 GENES ANALYZED IN GENOME WIDE TRANSCRIPTION PROFILING, ABOUT 1% WERE DIFFERENTIALLY EXPRESSED BETWEEN HCV-RESPONSIVE TREG, HCV-NON-RESPONSIVE NATURAL CD25(+) CELLS AND CONVENTIONAL T CELLS. EXPRESSION PROFILES, INCLUDING CELL DEATH, ACTIVATION, PROLIFERATION AND TRANSCRIPTIONAL REGULATION, SUGGEST A SURVIVAL ADVANTAGE OF HCV-RESPONSIVE TREG OVER THE OTHER CELL POPULATIONS. SINCE NO TREG-SPECIFIC ACTIVATION MARKER IS KNOWN, WE TESTED 97 NS3-DERIVED PEPTIDES FOR THEIR ABILITY TO ELICIT CD25 RESPONSE (ASSUMING IT IS A SURROGATE MARKER), ACCOMPANIED BY HIGH RESOLUTION HLA TYPING OF THE PATIENTS. SOME REACTIVE PEPTIDES OVERLAPPED WITH PREVIOUSLY DESCRIBED EFFECTOR T CELL EPITOPES. OUR DATA OFFERS NEW INSIGHTS INTO HCV IMMUNE EVASION AND TOLERANCE, AND HIGHLIGHTS THE NON-SELF SPECIFIC NATURE OF TREG DURING INFECTION. 2009 4 556 48 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 5 5509 43 RHPLD2 INHIBITS AIRWAY INFLAMMATION IN AN ASTHMATIC MURINE MODEL THROUGH INDUCTION OF STABLE CD25(+) FOXP3(+) TREGS. OUR PREVIOUS STUDIES HAVE SHOWN THAT RECOMBINANT HUMAN PHOSPHOLIPASE D2 (RHPLD2) PLAYS A MODULATOR ROLE ON NF-KAPPAB AND PKC SIGNALING PATHWAYS. IT ALSO INHIBITS IL-5-INDUCED INFLAMMATORY RESPONSE IN CHRONIC ASTHMATIC GUINEA PIGS. ADDITIONALLY, INCREASING EVIDENCE ALSO HAS REVEALED THAT THE ADOPTIVE TRANSFER OF INDUCED REGULATORY T CELLS (TREGS) MAY BE A THERAPEUTIC SOLUTION TO AIRWAY ALLERGIC DISEASES. TO INVESTIGATE THE EPIGENETIC, TRANSCRIPTOMIC AND PHENOTYPIC VARIABILITY OF TREG POPULATION IN AN OVALBUMIN (OVA)-INDUCED AIRWAY INFLAMMATION MODEL DERIVED FROM THE INDUCTION OF RHPLD2, OVA-INDUCED ASTHMATIC MURINE MODEL IS USED IN THIS STUDY. THE LUNG INFLAMMATION, EOSINOPHIL INFILTRATION, THE DIFFERENTIATION AND PROLIFERATION OF T HELPER CELLS AND THE AMPLIFICATION OF TREGS WERE EXAMINED IN THIS MOUSE MODEL WITH AND WITHOUT RHPLD2 INDUCTION. OUR DATA SHOWED THAT RHPLD2 ADMINISTRATION IN ASTHMATIC MICE SIGNIFICANTLY INCREASES CD4(+)CD25(+) FOXP3(+) TREG CELL NUMBERS AND ALLEVIATES LUNG INFLAMMATION. THE ADDITION OF RHPLD2 IN VITRO ENHANCED THE DEMETHYLATION OF TREG-SPECIFICDEMETHYLATED REGION (TSDR) IN ITREGS, SUGGESTING THAT RHPLD2 PROTEIN MAY BE INVOLVED IN IMPROVING THE QUALITY AND QUANTITY OF TREG CELLS THAT EVENTUALLY SIGNIFICANTLY REDUCES LUNG INFLAMMATION IN ASTHMATIC MURINE MODEL. THESE RESULTS SUGGEST THAT RHPLD2 COULD HAVE A CLINICAL IMPACT TREATING PATIENTS WITH ALLERGIC AIRWAY INFLAMMATION VIA PROMOTING AND STABILIZING ITREG DIFFERENTIATION AND FUNCTION. 2018 6 3454 38 HYPOMETHYLATION AT THE REGULATORY T CELL-SPECIFIC DEMETHYLATED REGION IN CD25HI T CELLS IS DECOUPLED FROM FOXP3 EXPRESSION AT THE INFLAMED SITE IN CHILDHOOD ARTHRITIS. THE MAINTENANCE OF FOXP3 EXPRESSION IN CD25(HI) REGULATORY T CELLS (TREGS) IS CRUCIAL TO THE CONTROL OF INFLAMMATION AND ESSENTIAL FOR SUCCESSFUL TREG TRANSFER THERAPIES. COEXPRESSION OF CD25 AND FOXP3 IN COMBINATION WITH A HYPOMETHYLATED REGION WITHIN THE FOXP3 GENE, CALLED THE TREG-SPECIFIC DEMETHYLATED REGION (TSDR), IS CONSIDERED THE HALLMARK OF STABLE TREGS. THE TSDR IS AN EPIGENETIC MOTIF THAT IS IMPORTANT FOR STABLE FOXP3 EXPRESSION AND IS USED AS A BIOMARKER TO MEASURE TREG LINEAGE COMMITMENT. IN THIS STUDY, WE REPORT THAT, UNLIKE IN PERIPHERAL BLOOD, CD4(+) T CELL EXPRESSION OF CD25 AND FOXP3 IS FREQUENTLY DISSOCIATED AT THE INFLAMED SITE IN PATIENTS WITH JUVENILE IDIOPATHIC ARTHRITIS, WHICH LED US TO QUESTION THE STABILITY OF HUMAN TREGS IN CHRONIC INFLAMMATORY ENVIRONMENTS. WE DESCRIBE A NOVEL CD4(+)CD127(LO)CD25(HI) HUMAN T CELL POPULATION THAT EXHIBITS EXTENSIVE TSDR AND PROMOTER DEMETHYLATION IN THE ABSENCE OF STABLE FOXP3 EXPRESSION. THIS POPULATION EXPRESSES HIGH LEVELS OF CTLA-4 AND CAN SUPPRESS T CONVENTIONAL CELL PROLIFERATION IN VITRO. THESE DATA COLLECTIVELY SUGGEST THAT THIS POPULATION MAY REPRESENT A CHRONICALLY ACTIVATED FOXP3(LO) TREG POPULATION. WE SHOW THAT THESE CELLS HAVE DEFECTS IN IL-2 SIGNALING AND REDUCED EXPRESSION OF A DEUBIQUITINASE IMPORTANT FOR FOXP3 STABILITY. CLINICALLY, THE PROPORTIONS OF THESE CELLS WITHIN THE CD25(HI) T CELL SUBSET ARE INCREASED IN PATIENTS WITH THE MORE SEVERE COURSES OF DISEASE. OUR STUDY DEMONSTRATES, THEREFORE, THAT HYPOMETHYLATION AT THE TSDR CAN BE DECOUPLED FROM FOXP3 EXPRESSION IN HUMAN T CELLS AND THAT ENVIRONMENT-SPECIFIC BREAKDOWN IN FOXP3 STABILITY MAY COMPROMISE THE RESOLUTION OF INFLAMMATION IN JUVENILE IDIOPATHIC ARTHRITIS. 2014 7 3893 27 LACTATE INDUCES METABOLIC AND EPIGENETIC REPROGRAMMING OF PRO-INFLAMMATORY TH17 CELLS. INCREASED LACTATE LEVELS IN THE TISSUE MICROENVIRONMENT ARE A WELL-KNOWN FEATURE OF CHRONIC INFLAMMATION. HOWEVER, THE ROLE OF LACTATE IN REGULATING T CELL FUNCTION REMAINS CONTROVERSIAL. HERE, WE DEMONSTRATE THAT EXTRACELLULAR LACTATE PREDOMINANTLY INDUCES DEREGULATION OF THE TH17-SPECIFIC GENE EXPRESSION PROGRAM BY MODULATING THE METABOLIC AND EPIGENETIC STATUS OF TH17 CELLS. FOLLOWING LACTATE TREATMENT, TH17 CELLS SIGNIFICANTLY REDUCED THEIR IL-17A PRODUCTION AND UPREGULATED FOXP3 EXPRESSION THROUGH ROS-DRIVEN IL-2 SECRETION. MOREOVER, WE OBSERVED INCREASED LEVELS OF GENOME-WIDE HISTONE H3K18 LACTYLATION, A RECENTLY DESCRIBED MARKER FOR ACTIVE CHROMATIN IN MACROPHAGES, IN LACTATE-TREATED TH17 CELLS. IN ADDITION, WE SHOW THAT HIGH LACTATE CONCENTRATIONS SUPPRESS TH17 PATHOGENICITY DURING INTESTINAL INFLAMMATION IN MICE. THESE RESULTS INDICATE THAT LACTATE IS CAPABLE OF REPROGRAMMING PRO-INFLAMMATORY T CELL PHENOTYPES INTO REGULATORY T CELLS. 2022 8 2389 30 EPIGENETIC REPOLARIZATION OF T LYMPHOCYTES FROM CHRONIC LYMPHOCYTIC LEUKEMIA PATIENTS USING 5-AZA-2'-DEOXYCYTIDINE. T CELL IMMUNE DYSFUNCTION HAS AN IMPORTANT ROLE IN THE PROFOUND IMMUNE SUPPRESSION THAT CHARACTERIZES CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). IMPROPER POLARIZATION OF T CELLS HAS BEEN PROPOSED AS ONE OF THE MECHANISM INVOLVED. MOUNTING DATA IMPLICATES CHROMATIN REGULATION, NAMELY PROMOTER METHYLATION, IN THE PLASTICITY OF NAIVE HUMAN T CELLS. RECENT IN VITRO EVIDENCE INDICATES THAT THIS PLASTICITY MAY BE PHENOTYPICALLY ALTERED BY USING METHYLATION INHIBITORS WHICH ARE APPROVED FOR CLINICAL USE IN CERTAIN TYPES OF CANCER. THESE RESULTS BEG THE QUESTION: CAN THE INEFFECTIVE POLARIZATION OF T LYMPHOCYTES IN THE CONTEXT OF CLL BE EFFECTIVELY MODULATED USING METHYLATION INHIBITORS IN A SUSTAINABLE THERAPEUTIC FASHION? TO ANSWER THIS QUESTION OUR LABORATORY HAS STUDIED THE EFFECTS OF 5-AZA-2'-DEOXYCYTIDINE (5A2) IN HELPER AND CYTOTOXIC T LYMPHOCYTES FROM HEALTHY DONORS AND CLL PATIENTS IN WELL CHARACTERIZED MOLECULAR AND EPIGENETIC SIGNALING PATHWAYS INVOLVED IN EFFECTIVE POLARIZATION. MOREOVER, WE SOUGHT TO INVESTIGATE THE CONSEQUENCES OF METHYLATION INHIBITOR TREATMENT ON LYMPHOCYTE SURVIVAL, ACTIVATION INTENSITY, AND NAIVE CELL POLARIZATION. OUR DATA INDICATES THAT 5A2 TREATMENT CAN DEPOLARIZE TH2 CELLS TO EFFECTIVELY SECRETE INTERFERON GAMMA, SIGNAL VIA T-BET, AND ACHIEVE DEMETHYLATION OF CRITICAL TH1 SPECIFIC PROMOTERS. MOREOVER, WE DEMONSTRATE THAT 5A2 CAN FORCE TH1 POLARIZATION OF NAIVE T CELLS DESPITE A STRONG IL-4 STIMULI AND A LACK OF IL-12. IN CONCLUSION OUR DATA SEEKS TO DEFINE A MODALITY IN WHICH IMPROPER OR INEFFECTIVE T CELL POLARIZATION CAN BE ALTERED BY 5AZA AND COULD BE INCORPORATED IN FUTURE THERAPEUTIC INTERVENTIONS. 2011 9 3998 34 LOSS OF EPIGENETIC MODIFICATION DRIVEN BY THE FOXP3 TRANSCRIPTION FACTOR LEADS TO REGULATORY T CELL INSUFFICIENCY. REGULATORY T (TREG) CELLS, DRIVEN BY THE FOXP3 TRANSCRIPTION FACTOR, ARE RESPONSIBLE FOR LIMITING AUTOIMMUNITY AND CHRONIC INFLAMMATION. WE SHOWED THAT A WELL-CHARACTERIZED FOXP3(GFP) REPORTER MOUSE, WHICH EXPRESSES AN N-TERMINAL GFP-FOXP3 FUSION PROTEIN, IS A HYPOMORPH THAT CAUSES PROFOUNDLY ACCELERATED AUTOIMMUNE DIABETES ON A NOD BACKGROUND. ALTHOUGH NATURAL TREG CELL DEVELOPMENT AND IN VITRO FUNCTION ARE NOT MARKEDLY ALTERED IN FOXP3(GFP) NOD AND C57BL/6 MICE, TREG CELL FUNCTION IN INFLAMMATORY ENVIRONMENTS WAS PERTURBED AND TGF-BETA-INDUCED TREG CELL DEVELOPMENT WAS REDUCED. FOXP3(GFP) WAS UNABLE TO INTERACT WITH THE HISTONE ACETYLTRANSFERASE TIP60, THE HISTONE DEACETYLASE HDAC7, AND THE IKAROS FAMILY ZINC FINGER 4, EOS, WHICH LED TO REDUCED FOXP3 ACETYLATION AND ENHANCED K48-LINKED POLYUBIQUITYLATION. COLLECTIVELY THIS RESULTS IN AN ALTERED TRANSCRIPTIONAL LANDSCAPE AND REDUCED FOXP3-MEDIATED GENE REPRESSION, NOTABLY AT THE HALLMARK IL-2 PROMOTER. LOSS OF CONTROLLED FOXP3-DRIVEN EPIGENETIC MODIFICATION LEADS TO TREG CELL INSUFFICIENCY THAT ENABLES AUTOIMMUNITY IN SUSCEPTIBLE ENVIRONMENTS. 2012 10 164 33 ABNORMAL HISTONE METHYLATION IS RESPONSIBLE FOR INCREASED VASCULAR ENDOTHELIAL GROWTH FACTOR 165A SECRETION FROM AIRWAY SMOOTH MUSCLE CELLS IN ASTHMA. VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF), A KEY ANGIOGENIC MOLECULE, IS ABERRANTLY EXPRESSED IN SEVERAL DISEASES INCLUDING ASTHMA WHERE IT CONTRIBUTES TO BRONCHIAL VASCULAR REMODELING AND CHRONIC INFLAMMATION. ASTHMATIC HUMAN AIRWAY SMOOTH MUSCLE CELLS HYPERSECRETE VEGF, BUT THE MECHANISM IS UNCLEAR. IN THIS STUDY, WE DEFINED THE MECHANISM IN HUMAN AIRWAY SMOOTH MUSCLE CELLS FROM NONASTHMATIC AND ASTHMATIC PATIENTS. WE FOUND THAT ASTHMATIC CELLS LACKED A REPRESSION COMPLEX AT THE VEGF PROMOTER, WHICH WAS PRESENT IN NONASTHMATIC CELLS. RECRUITMENT OF G9A, TRIMETHYLATION OF HISTONE H3 AT LYSINE 9 (H3K9ME3), AND A RESULTANT DECREASE IN RNA POLYMERASE II AT THE VEGF PROMOTER WAS CRITICAL TO REPRESSION OF VEGF SECRETION IN NONASTHMATIC CELLS. AT THE ASTHMATIC PROMOTER, H3K9ME3 WAS ABSENT BECAUSE OF FAILED RECRUITMENT OF G9A; RNA POLYMERASE II BINDING, IN ASSOCIATION WITH TATA-BINDING PROTEIN-ASSOCIATED FACTOR 1, WAS INCREASED; H3K4ME3 WAS PRESENT; AND SP1 BINDING WAS EXAGGERATED AND SUSTAINED. IN CONTRAST, DNA METHYLATION AND HISTONE ACETYLATION WERE SIMILAR IN ASTHMATIC AND NONASTHMATIC CELLS. THIS IS THE FIRST STUDY, TO OUR KNOWLEDGE, TO SHOW THAT AIRWAY CELLS IN ASTHMA HAVE ALTERED EPIGENETIC REGULATION OF REMODELING GENE(S). HISTONE METHYLATION AT GENES SUCH AS VEGF MAY BE AN IMPORTANT NEW THERAPEUTIC TARGET. 2012 11 6765 38 ZINC DEFICIENCY LEADS TO REDUCED INTERLEUKIN-2 PRODUCTION BY ACTIVE GENE SILENCING DUE TO ENHANCED CREMALPHA EXPRESSION IN T CELLS. BACKGROUND & AIMS: THE MICRONUTRIENT ZINC IS ESSENTIAL FOR PROPER IMMUNE FUNCTION. CONSEQUENTLY, ZINC DEFICIENCY LEADS TO IMPAIRED IMMUNE FUNCTION, AS SEEN IN DECREASED SECRETION OF INTERLEUKIN (IL)-2 BY T CELLS. ALTHOUGH THIS ASSOCIATION HAS BEEN KNOWN SINCE THE LATE 1980S, THE UNDERLYING MOLECULAR MECHANISMS ARE STILL UNKNOWN. ZINC DEFICIENCY AND REDUCED IL-2 LEVELS ARE ESPECIALLY FOUND IN THE ELDERLY, WHICH IN TURN ARE PRONE TO CHRONIC DISEASES. HERE, WE DESCRIBE A NEW MOLECULAR LINK BETWEEN ZINC DEFICIENCY AND REDUCED IL-2 EXPRESSION IN T CELLS. METHODS: THE EFFECTS OF ZINC DEFICIENCY WERE FIRST INVESTIGATED IN VITRO IN THE HUMAN T CELL LINES JURKAT AND HUT-78 AND COMPLEMENTED BY IN VIVO DATA FROM ZINC-SUPPLEMENTED PIGS. A SHORT- AND LONG-TERM MODEL FOR ZINC DEFICIENCY WAS ESTABLISHED. ZINC LEVELS WERE DETECTED BY FLOW CYTOMETRY AND EXPRESSION PROFILES WERE INVESTIGATED ON THE MRNA AND PROTEIN LEVEL. RESULTS: THE EXPRESSION OF THE TRANSCRIPTION FACTOR CAMP-RESPONSIVE-ELEMENT MODULATOR ALPHA (CREMALPHA) IS INCREASED DURING ZINC DEFICIENCY IN VITRO, DUE TO INCREASED PROTEIN PHOSPHATASE 2A (PP2A) ACTIVITY, RESULTING IN DECREASED IL-2 PRODUCTION. ADDITIONALLY, ZINC SUPPLEMENTATION IN VIVO REDUCED CREMALPHA LEVELS CAUSING INCREASED IL-2 EXPRESSION. ON EPIGENETIC LEVELS INCREASED CREMALPHA BINDING TO THE IL-2 PROMOTER IS MEDIATED BY HISTONE DEACETYLASE 1 (HDAC1). THE HDAC1 ACTIVITY IS INHIBITED BY ZINC. MOREOVER, DEACETYLATION OF THE ACTIVATING HISTONE MARK H3K9 WAS INCREASED UNDER ZINC DEFICIENCY, RESULTING IN REDUCED IL-2 EXPRESSION. CONCLUSIONS: WITH THE TRANSCRIPTION FACTOR CREMALPHA A MOLECULAR LINK WAS UNCOVERED, CONNECTING ZINC DEFICIENCY WITH REDUCED IL-2 PRODUCTION DUE TO ENHANCED PP2A AND HDAC1 ACTIVITY. 2021 12 6020 41 THE ATTENUATION OF RENAL FIBROSIS BY HISTONE DEACETYLASE INHIBITORS IS ASSOCIATED WITH THE PLASTICITY OF FOXP3(+)IL-17(+) T CELLS. BACKGROUND: THE HISTONE DEACETYLASE (HDAC) INHIBITOR, WHICH HAS POTENTIAL EFFECTS ON EPIGENETIC MODIFICATIONS, HAD BEEN REPORTED TO ATTENUATE RENAL FIBROSIS. CD4(+) FORKHEAD BOX P3 (FOXP3)(+) T REGULATORY (TREG) CELLS MAY BE CONVERTED TO INFLAMMATION-ASSOCIATED T HELPER 17 CELLS (TH17) WITH TISSUE FIBROSIS PROPERTIES. THE ASSOCIATION BETWEEN FOXP3(+)IL-17(+) T CELLS AND THE ATTENUATION OF RENAL FIBROSIS BY THE HDAC INHIBITOR IS NOT CLEAR. METHODS: THIS STUDY EVALUATED THE ROLES OF THE HDAC INHIBITOR, TREG CELLS AND THEIR DIFFERENTIATION INTO TH17 CELLS, WHICH AGGRAVATE CHRONIC INFLAMMATION AND RENAL FIBROSIS IN A UNILATERAL URETERAL OBSTRUCTION (UUO) MOUSE MODEL. THE STUDY GROUPS INCLUDED CONTROL AND UUO MICE THAT WERE MONITORED FOR 7, 14 OR 21 DAYS. RESULTS: JUXTAGLOMERULAR (JG) HYPERPLASIA, ANGIOTENSIN II TYPE 1 RECEPTOR (AT1R) EXPRESSION AND LYMPHOCYTE INFILTRATION WERE OBSERVED IN RENAL TISSUES AFTER UUO BUT WERE DECREASED AFTER TRICHOSTATIN A (TSA) TREATMENT, A HDAC INHIBITOR. THE NUMBER OF CD4(+)FOXP3(+) T CELLS INCREASED PROGRESSIVELY, ALONG WITH THE NUMBER OF FOXP3(+)INTERLEUKIN (IL)-17(+) T CELLS, AFTER 14 DAYS, AND THEIR NUMBERS THEN PROGRESSIVELY DECREASED WITH INCREASING CD4(+)IL-17(+) T CELL NUMBERS, AS DEMONSTRATED BY DOUBLE IMMUNOHISTOCHEMISTRY. PROGRESSIVE RENAL FIBROSIS WAS ASSOCIATED WITH THE LOSS OF CD4(+)FOXP3(+)IL-17(+) T CELLS IN SPLENIC SINGLE-CELL SUSPENSIONS. FOXP3(+)IL-17(+) T CELLS EXPRESSED TGF-BETA1 BOTH IN VITRO AND IN VIVO, AND TGF-BETA1 EXPRESSION WAS SIGNIFICANTLY KNOCKDOWN BY IL-17 SIRNA IN VITRO. THESE CELLS WERE FOUND TO PLAY A ROLE IN CONVERTING TREGS INTO IL-17- AND TGF-BETA1-PRODUCING CELLS. CONCLUSIONS: TSA TREATMENT DECREASED JG HYPERPLASIA, THE PERCENTAGE OF FOXP3(+)IL-17(+) CELLS AND THE DEGREE OF FIBROSIS, SUGGESTING THAT THERAPEUTIC BENEFITS MAY RESULT FROM EPIGENETIC MODIFICATIONS. 2017 13 2200 36 EPIGENETIC MODIFICATION OF FOXP3 IN PATIENTS WITH CHRONIC HIV INFECTION. OBJECTIVES: HIV-1 MODULATES HOST CELL EPIGENETIC MACHINERY TO CONTROL ITS OWN REPLICATION AND INDUCE IMMUNE SUPPRESSION. HIV-1 INFECTION LEADS TO ACTIVATION OF T REGULATORY CELL (T(REG)), BUT THE MECHANISM UNDERLYING THIS IMMUNE MODULATION IS UNCLEAR. T(REG) PLAYS A PROMINENT ROLE IN GUT-MUCOSAL IMMUNE TOLERANCE BY RESTRAINING EXCESSIVE EFFECTOR T-CELL RESPONSES, A MECHANISM THAT IS KNOWN TO BE DISTURBED IN CHRONIC HIV-1 INFECTION. DNA METHYLATION PLAYS A MAJOR ROLE IN T(REG) LINEAGE COMMITMENT AND IMMUNE HOMEOSTASIS, WHICH MAY BE REGULATED BY HIV. TO INVESTIGATE THE MECHANISMS OF ABERRANT METHYLATION OF THE T(REG) MARKER FOXP3 IN HIV-1 INFECTION, WE EVALUATED THE EXPRESSION PATTERN OF METHYLATION-RELATED ENZYMES AND ITS CORRELATION TO FOXP3 METHYLATION. METHODS: FOXP3 PROMOTER METHYLATION IN THE COLON MUCOSA AND PERIPHERAL BLOOD FROM HIV-INFECTED PATIENTS AND CONTROL SUBJECTS WAS MEASURED USING PYROSEQUENCING. GENE EXPRESSION PATTERN OF DNA METHYLATION ENZYMES IN THE COLON MUCOSA WAS INVESTIGATED BY MICROARRAY AND QUANTITATIVE REVERSE TRANSCRIPTASE-POLYMERASE CHAIN REACTION ANALYSIS IN THE SAME SUBJECTS. RESULTS: FOXP3 PROMOTER WAS SIGNIFICANTLY (P