1 223 143 ACUTE PSYCHOSOCIAL STRESS-MEDIATED CHANGES IN THE EXPRESSION AND METHYLATION OF PERFORIN IN CHRONIC FATIGUE SYNDROME. PERFORIN (PRF1) IS ESSENTIAL FOR IMMUNE SURVEILLANCE AND STUDIES REPORT DECREASED PERFORIN IN CHRONIC FATIGUE SYNDROME (CFS), AN ILLNESS POTENTIALLY ASSOCIATED WITH STRESS AND/OR INFECTION. WE HYPOTHESIZE THAT STRESS CAN INFLUENCE REGULATION OF PRF1 EXPRESSION, AND THAT THIS REGULATION WILL DIFFER BETWEEN CFS AND NON-FATIGUED (NF) CONTROLS. WE USED THE TRIER SOCIAL STRESS TEST (TSST) AS A STANDARDIZED ACUTE PSYCHOSOCIAL STRESS, AND EVALUATED ITS EFFECT ON PRF1 EXPRESSION AND METHYLATION IN CFS (N = 34) COMPARED WITH NF (N = 47) PARTICIPANTS. DURING THE TSST, NATURAL KILLER (NK) CELLS INCREASED SIGNIFICANTLY IN BOTH CFS (P = <0.0001) AND NF SUBJECTS (P = <0.0001). UNLIKE PREVIOUS REPORTS, THERE WAS NO SIGNIFICANT DIFFERENCE IN PRF1 EXPRESSION AT BASELINE OR DURING TSST BETWEEN CFS AND NF. HOWEVER, WHOLE BLOOD PRF1 EXPRESSION INCREASED 1.6 FOLD DURING THE TSST IN BOTH CFS (P = 0.0003) AND NF (P = <0.0001). FURTHER, THE PEAK RESPONSE IMMEDIATELY FOLLOWING THE TSST WAS LOWER IN CFS COMPARED WITH NF (P = 0.04). IN ADDITION, AT 1.5 HOURS POST TSST, PRF1 EXPRESSION WAS ELEVATED IN CFS COMPARED WITH NF (WHOLE BLOOD, P = 0.06; PBMC, P = 0.02). METHYLATION OF SEVEN CPG SITES IN THE METHYLATION SENSITIVE REGION OF THE PRF1 PROMOTER RANGED FROM 38%-79% WITH NO SIGNIFICANT DIFFERENCES BETWEEN CFS AND NF. ALTHOUGH, THE AVERAGE BASELINE METHYLATION OF ALL SEVEN CPG SITES DID NOT DIFFER BETWEEN CFS AND NF GROUPS, IT SHOWED A SIGNIFICANT NEGATIVE CORRELATION WITH PRF1 EXPRESSION AT ALL TSST TIME POINTS IN BOTH CFS (R = -0.56, P = <0.0001) AND NF (R = -0.38, P = <0.0001). AMONG PARTICIPANTS WITH HIGH AVERAGE METHYLATION (>/=65%), PRF1 EXPRESSION WAS SIGNIFICANTLY LOWER IN CFS THAN NF SUBJECTS IMMEDIATELY FOLLOWING TSST. THESE FINDINGS SUGGEST METHYLATION COULD BE AN IMPORTANT EPIGENETIC DETERMINANT OF INTER-INDIVIDUAL DIFFERENCES IN PRF1 EXPRESSION AND THAT THE DIFFERENCES IN PRF1 EXPRESSION AND METHYLATION BETWEEN CFS AND NF IN THE ACUTE STRESS RESPONSE REQUIRE FURTHER INVESTIGATION. 2013 2 4308 35 MICRORNA?155 MODULATION OF CD8(+) T?CELL ACTIVITY PERSONALIZES RESPONSE TO DISEASE?MODIFYING THERAPIES OF PATIENTS WITH RELAPSING?REMITTING MULTIPLE SCLEROSIS. MULTIPLE SCLEROSIS (MS) IS A CHRONIC AUTOIMMUNE DISEASE WHERE ACTIVATED IMMUNE CELLS CAN ATTACK OLIGODENDROCYTES CAUSING DAMAGE TO THE MYELIN SHEATH. SEVERAL MOLECULAR MECHANISMS ARE RESPONSIBLE FOR THE AUTO-ACTIVATION OF IMMUNE CELLS SUCH AS RNA INTERFERENCE (RNAI) THROUGH MICRORNAS (MIRNAS OR MIRS). IN THE PRESENT STUDY, THE ROLE OF MIR-155 IN REGULATING CD8(+) T-CELL ACTIVITY IN PATIENTS WITH RELAPSING-REMITTING MULTIPLE SCLEROSIS (RRMS) WAS INVESTIGATED, IN TERMS OF ITS MIGRATORY FUNCTIONS WITH REGARD TO INTRACELLULAR ADHESION MOLECULE-1 (ICAM1) AND INTEGRIN SUBUNIT BETA2 (ITGB2), AND ITS CYTOTOXIC PROTEINS, PERFORIN AND GRANZYME B. GENE EXPRESSION OF MIR-155, ICAM1, ITGB2, PERFORIN AND GRANZYME B WAS EVALUATED FOLLOWING EPIGENETIC MODULATIONS USING REVERSE TRANSCRIPTION-QUANTITATIVE POLYMERASE CHAIN REACTION IN CD8(+) T-CELLS ISOLATED FROM BLOOD SAMPLES OF PATIENTS WITH RRMS AND COMPARED TO HEALTHY CONTROLS. THE ECTOPIC EXPRESSION OF MIR-155 RESULTED IN A PERSISTENT DOWNREGULATION IN ALL GENES OF INTEREST RELATED TO CD8(+) T-CELL ACTIVATION THAT WERE POSITIVELY CORRELATED WITH THE EXPANDED DISABILITY STATUS SCALE OF PATIENTS. THE PRESENT STUDY REVEALED THE INTERPLAY BETWEEN MIR-155, ICAM1, AND ITGB2, SHEDDING LIGHT ON THEIR BENEFICIAL USE AS POSSIBLE THERAPEUTIC REGULATORS AND DIAGNOSTIC BIOMARKERS OF DISEASE. MOREOVER, EPIGENETIC MODULATIONS ENHANCING THE EFFICACY OF DISEASE-MODIFYING THERAPIES (DMTS) MAY BE EMPLOYED AS PERSONALIZED THERAPY, TO DECREASE THE SIDE EFFECTS OF DMTS AND IMPROVE THE OUTCOMES OF PATIENTS. 2023 3 2559 35 EPIGENETICS IN SYSTEMIC LUPUS ERYTHEMATOSUS: LEADING THE WAY FOR SPECIFIC THERAPEUTIC AGENTS. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC AUTOIMMUNE DISORDER OF AN UNCLEARLY DETERMINED ETIOLOGY. PAST STUDIES, BOTH EPIDEMIOLOGICAL AND BIOLOGICAL, HAVE IMPLICATED EPIGENETIC INFLUENCES IN DISEASE ETIOLOGY AND PATHOGENESIS. EPIGENETICS DESCRIBES CHANGES IN GENE EXPRESSION NOT LINKED TO ALTERATIONS IN THE UNDERLYING GENOMIC SEQUENCE, AND IS MOST OFTEN TYPIFIED BY THREE MODIFICATIONS: METHYLATION OF DNA, ADDITION OF VARIOUS SIDE CHAINS TO HISTONE GROUPS AND TRANSCRIPTIONAL REGULATION VIA SHORT NCRNA SEQUENCES. THE PURPOSE OF THIS ARTICLE IS TO REVIEW THE MOST IMPORTANT ADVANCES THAT LINK EPIGENETIC CHANGES TO LUPUS. THE CONTRIBUTION OF DNA METHYLATION CHANGES TO LUPUS PATHOGENESIS IS DISCUSSED. THESE INCLUDE THE ROLE OF APOPTOTIC DNA, ULTRAVIOLET RADIATION, ENDOGENOUS RETROVIRUSES, DIETARY CONTRIBUTIONS AND AGING. HYPOMETHYLATION OF SPECIFIC GENES OVEREXPRESSED IN LUPUS T CELLS SUCH AS ITGAL (CD11A), CD40LG (CD40L), TNFSF7 (CD70), KIR2DL4 AND PRF1 (PERFORIN), AND CD5 IN LUPUS B CELLS SEEM TO PLAY AN IMPORTANT ROLE. MOREOVER, HISTONE MODIFICATIONS SUCH AS INCREASED GLOBAL H4 ACETYLATION IN MONOCYTES ARE HIGHLY ASSOCIATED WITH SLE. NCRNAS, ESPECIALLY MIR-21, MIR-148A AND MIR-126, CONTROL OTHER ELEMENTS OF EPIGENETIC REGULATION; PARTICULARLY, TRANSCRIPTION OF THE MAINTENANCE DNA METHYLATION ENZYME DNMT1. EPIGENETIC CONTRIBUTIONS TO SLE ETIOLOGY HAVE BEEN WELL ESTABLISHED, BUT MUCH IS STILL UNKNOWN. EPIGENOME-WIDE STUDIES COUPLED WITH FUNCTIONAL ANALYSIS OF THE EPIGENOMIC CHANGES DISCOVERED WILL UNCOVER NOVEL PATHWAYS IMPORTANT IN DISEASE PATHOGENESIS. EPIGENETIC THERAPIES FOR SLE MAY BE FEASIBLE IN THE FUTURE, PARTICULARLY IF THEY ARE DESIGNED TO TARGET SPECIFIC REGIONS WITHIN THE GENOME. 2011 4 3373 30 HISTONE MODULATION BLOCKS TREG-INDUCED FOXP3 BINDING TO THE IL-2 PROMOTER OF VIRUS-SPECIFIC CD8(+) T CELLS FROM FELINE IMMUNODEFICIENCY VIRUS-INFECTED CATS. CD8(+) T CELLS ARE CRITICAL FOR CONTROLLING HIV INFECTION. DURING THE CHRONIC PHASE OF LENTIVIRAL INFECTION, CD8(+) T CELLS LOSE THEIR PROLIFERATIVE CAPACITY AND EXHIBIT IMPAIRED ANTIVIRAL FUNCTION. THIS LOSS OF CD8(+) T CELL FUNCTION IS DUE, IN PART, TO CD4(+)CD25(+) T REGULATORY (TREG) CELL-MEDIATED SUPPRESSION. OUR RESEARCH GROUP HAS DEMONSTRATED THAT LENTIVIRUS-ACTIVATED CD4(+)CD25(+) TREG CELLS INDUCE THE REPRESSIVE TRANSCRIPTION FACTOR FORKHEAD BOX P3 (FOXP3) IN AUTOLOGOUS CD8(+) T CELLS FOLLOWING CO-CULTURE. WE HAVE RECENTLY REPORTED THAT TREG-INDUCED FOXP3 BINDS THE INTERLEUKIN-2 (IL-2), INTERFERON-GAMMA (IFN- GAMMA), AND TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA) PROMOTERS IN VIRUS-SPECIFIC CD8(+) T CELLS. THESE DATA SUGGEST AN IMPORTANT ROLE OF FOXP3-MEDIATED CD8(+) T CELL DYSFUNCTION IN LENTIVIRAL INFECTION. TO ELUCIDATE THE MECHANISM OF THIS SUPPRESSION, WE PREVIOUSLY REPORTED THAT DECREASED METHYLATION FACILITATES FOXP3 BINDING IN MITOGEN-ACTIVATED CD8(+) T CELLS FROM FELINE IMMUNODEFICIENCY VIRUS (FIV)-INFECTED CATS. WE DEMONSTRATED THE REDUCED BINDING OF FOXP3 TO THE IL-2 PROMOTER BY INCREASING METHYLATION OF CD8(+) T CELLS. IN THE STUDIES PRESENTED HERE, WE ASK IF ANOTHER FORM OF EPIGENETIC MODULATION MIGHT ALLEVIATE FOXP3-MEDIATED SUPPRESSION IN CD8(+) T CELLS. WE HYPOTHESIZED THAT DECREASING HISTONE ACETYLATION IN VIRUS-SPECIFIC CD8(+) T CELLS WOULD DECREASE TREG-INDUCED FOXP3 BINDING TO THE IL-2 PROMOTER. INDEED, USING ANACARDIC ACID (AA), A KNOWN HISTONE ACETYL TRANSFERASE (HAT) INHIBITOR, WE DEMONSTRATE A REDUCTION IN FOXP3 BINDING TO THE IL-2 PROMOTER IN VIRUS-SPECIFIC CD8(+) T CELLS CO-CULTURED WITH AUTOLOGOUS TREG CELLS. THESE DATA IDENTIFY A NOVEL MECHANISM OF FOXP3-MEDIATED CD8(+) T CELL DYSFUNCTION DURING LENTIVIRAL INFECTION. 2018 5 1293 28 DECREASED ERK AND JNK SIGNALING CONTRIBUTE TO GENE OVEREXPRESSION IN "SENESCENT" CD4+CD28- T CELLS THROUGH EPIGENETIC MECHANISMS. AN INFLAMMATORY AND CYTOTOXIC CD4+CD28- T CELL SUBSET INFILTRATES ATHEROSCLEROTIC PLAQUES AND IS IMPLICATED IN PLAQUE RUPTURE AND MYOCARDIAL INFARCTIONS. THIS PATHOLOGIC SUBSET DEVELOPS WITH REPLICATIVE STRESS AND IS FOUND IN PATIENTS WITH CHRONIC INFLAMMATORY DISEASES SUCH AS RA AS WELL AS WITH AGING. CD4+CD28- CELLS OVEREXPRESS GENES NORMALLY SUPPRESSED BY DNA METHYLATION IN CD4+CD28+ T CELLS, SUCH AS KIR, PERFORIN, AND CD70. HOW THIS SUBSET OVER EXPRESSES METHYLATION-SENSITIVE GENES IS UNKNOWN. DNA METHYLATION PATTERNS ARE MAINTAINED IN PROLIFERATING CELLS BY DNMTS, WHICH ARE UP-REGULATED DURING MITOSIS BY THE ERK AND JNK SIGNALING PATHWAYS. WE HYPOTHESIZED THAT DEFECTS IN THESE SIGNALING PATHWAYS CONTRIBUTE TO ALTERED GENE EXPRESSION IN HUMAN CD4+CD28- CELLS THROUGH EFFECTS ON DNA METHYLATION. WE REPORT THAT SIGNALING THROUGH THE ERK AND JNK PATHWAYS IS DECREASED IN CD4+CD28- RELATIVE TO CD4+CD28+ CELLS FROM THE SAME INDIVIDUALS AND THAT ERK AND JNK PATHWAY INHIBITION DECREASES DNMT1 AND -3A LEVELS, WHICH IN TURN, CAUSES DEMETHYLATION AND OVEREXPRESSION OF THE TNFSF7 (CD70) GENE. WE ALSO REPORT THAT CD4+CD28- T CELLS OVEREXPRESS PP5, A STRESS-INDUCED INHIBITOR OF THE ERK AND JNK SIGNALING PATHWAYS THAT MAY CONTRIBUTE TO THE SIGNALING DEFECTS. WE CONCLUDE THAT DECREASED ERK AND JNK SIGNALING IN THE CD4+CD28- SUBSET, ARISING WITH REPLICATIVE STRESS, CAN LEAD TO THE OVEREXPRESSION OF NORMALLY SUPPRESSED GENES THROUGH EFFECTS ON DNMTS AND CONSEQUENTLY, CHROMATIN STRUCTURE. 2010 6 3167 35 GROUP 1 METABOTROPIC GLUTAMATE RECEPTOR EXPRESSION DEFINES A T CELL MEMORY POPULATION DURING CHRONIC TOXOPLASMA INFECTION THAT ENHANCES IFN-GAMMA AND PERFORIN PRODUCTION IN THE CNS. WITHIN THE BRAIN, A PRO-INFLAMMATORY RESPONSE IS ESSENTIAL TO PREVENT CLINICAL DISEASE DUE TO TOXOPLASMA GONDII REACTIVATION. INFECTION IN THE IMMUNOCOMPROMISED LEADS TO LETHAL TOXOPLASMIC ENCEPHALITIS WHILE IN THE IMMUNOCOMPETENT, THERE IS PERSISTENT LOW-GRADE INFLAMMATION WHICH IS DEVOID OF CLINICAL SYMPTOMS. THIS SIGNIFIES THAT THERE IS A WELL-BALANCED AND REGULATED INFLAMMATORY RESPONSE TO T. GONDII IN THE BRAIN. T CELLS ARE THE DOMINANT IMMUNE CELLS THAT PREVENT CLINICAL DISEASE, AND THIS IS MEDIATED THROUGH THE SECRETION OF EFFECTOR MOLECULES SUCH AS PERFORINS AND IFN-GAMMA. THE PRESENCE OF COGNATE ANTIGEN, THE EXPRESSION OF SURVIVAL CYTOKINES, AND THE ALTERATION OF THE EPIGENETIC LANDSCAPE DRIVE THE DEVELOPMENT OF MEMORY T CELLS. HOWEVER, SPECIFIC EXTRINSIC SIGNALS THAT PROMOTE THE FORMATION AND MAINTENANCE OF MEMORY T CELLS WITHIN TISSUE ARE POORLY UNDERSTOOD. DURING CHRONIC INFECTION, THERE IS AN INCREASE IN EXTRACELLULAR GLUTAMATE THAT, DUE TO ITS FUNCTION AS AN EXCITATORY NEUROTRANSMITTER, IS NORMALLY TIGHTLY CONTROLLED IN THE CNS. HERE WE DEMONSTRATE THAT CD8(+) T CELLS FROM THE T. GONDII-INFECTED BRAIN PARENCHYMA ARE ENRICHED FOR METABOTROPIC GLUTAMATE RECEPTORS (MGLUR'S). CHARACTERIZATION STUDIES DETERMINED THAT MGLUR(+) EXPRESSION BY CD8(+) T CELLS DEFINES A DISTINCT MEMORY POPULATION AT THE TRANSCRIPTIONAL AND PROTEIN LEVEL. FINALLY, USING RECEPTOR ANTAGONISTS AND AGONISTS WE DEMONSTRATE MGLUR SIGNALING IS REQUIRED FOR OPTIMAL CD8(+) T CELL PRODUCTION OF THE EFFECTOR CYTOKINE IFNGAMMA. THIS WORK SUGGESTS THAT GLUTAMATE IS AN IMPORTANT ENVIRONMENTAL SIGNAL OF INFLAMMATION THAT PROMOTES T CELL FUNCTION. UNDERSTANDING GLUTAMATE'S INFLUENCE ON T CELLS IN THE BRAIN CAN PROVIDE INSIGHTS INTO THE MECHANISMS THAT GOVERN PROTECTIVE IMMUNITY AGAINST CNS-INFILTRATING PATHOGENS AND NEUROINFLAMMATION. 2023 7 3953 33 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 8 2392 33 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 9 6481 28 TOX IS EXPRESSED BY EXHAUSTED AND POLYFUNCTIONAL HUMAN EFFECTOR MEMORY CD8(+) T CELLS. CD8(+) T CELL EXHAUSTION IS A HALLMARK OF MANY CANCERS AND CHRONIC INFECTIONS. IN MICE, T CELL FACTOR 1 (TCF-1) MAINTAINS EXHAUSTED CD8(+) T CELL RESPONSES, WHEREAS THYMOCYTE SELECTION-ASSOCIATED HMG BOX (TOX) IS REQUIRED FOR THE EPIGENETIC REMODELING AND SURVIVAL OF EXHAUSTED CD8(+) T CELLS. HOWEVER, IT HAS REMAINED UNCLEAR TO WHAT EXTENT THESE TRANSCRIPTION FACTORS PLAY ANALOGOUS ROLES IN HUMANS. IN THIS STUDY, WE MAPPED THE EXPRESSION OF TOX AND TCF-1 AS A FUNCTION OF DIFFERENTIATION AND SPECIFICITY IN THE HUMAN CD8(+) T CELL LANDSCAPE. HERE, WE DEMONSTRATE THAT CIRCULATING TOX(+) CD8(+) T CELLS EXIST IN MOST HUMANS, BUT THAT TOX IS NOT EXCLUSIVELY ASSOCIATED WITH EXHAUSTION. EFFECTOR MEMORY CD8(+) T CELLS GENERALLY EXPRESSED TOX, WHEREAS NAIVE AND EARLY-DIFFERENTIATED MEMORY CD8(+) T CELLS GENERALLY EXPRESSED TCF-1. CYTOLYTIC GENE AND PROTEIN EXPRESSION SIGNATURES WERE ALSO DEFINED BY THE EXPRESSION OF TOX. IN THE CONTEXT OF A RELENTLESS IMMUNE CHALLENGE, EXHAUSTED HIV-SPECIFIC CD8(+) T CELLS COMMONLY EXPRESSED TOX, OFTEN IN CLUSTERS WITH VARIOUS ACTIVATION MARKERS AND INHIBITORY RECEPTORS, AND EXPRESSED LESS TCF-1. HOWEVER, POLYFUNCTIONAL MEMORY CD8(+) T CELLS SPECIFIC FOR CYTOMEGALOVIRUS (CMV) OR EPSTEIN-BARR VIRUS (EBV) ALSO EXPRESSED TOX, EITHER WITH OR WITHOUT TCF-1. A SIMILAR PHENOTYPE WAS OBSERVED AMONG HIV-SPECIFIC CD8(+) T CELLS FROM INDIVIDUALS WHO MAINTAINED EXCEPTIONAL IMMUNE CONTROL OF VIRAL REPLICATION. COLLECTIVELY, THESE DATA DEMONSTRATE THAT TOX IS EXPRESSED BY MOST CIRCULATING EFFECTOR MEMORY CD8(+) T CELL SUBSETS AND NOT EXCLUSIVELY LINKED TO EXHAUSTION. 2020 10 2196 32 EPIGENETIC MODIFICATION MEDIATES THE INCREASE OF LAG-3(+) T CELLS IN CHRONIC OSTEOMYELITIS. IMMUNE SUPPRESSION PLAYS CRITICAL ROLES IN THE DEVELOPMENT OF CHRONIC OSTEOMYELITIS, AND THE MECHANISMS UNDERLYING THE DEVELOPMENT OF IMMUNE SUPPRESSION IN CHRONIC OSTEOMYELITIS HAVE ATTRACTED MUCH ATTENTION. LAG-3 IS AN IMPORTANT SUPPRESSOR OF T CELL ACTIVATION, BUT THE ROLE OF LAG-3 IN THE IMMUNE REGULATION OF CHRONIC OSTEOMYELITIS IS CURRENTLY UNKNOWN. WE SOUGHT TO DEMONSTRATE IF LAG-3 PLAYS CRUCIAL ROLES IN CHRONIC OSTEOMYELITIS PROGRESSION AND HAS EFFECTS ON IMMUNE SUPPRESSION AND EXHAUSTING OF T CELLS, AND WHAT IS THE MECHANISM UNDERLYING LAG-3 DEREGULATION IN CHRONIC OSTEOMYELITIS. WE EXAMINED THE EXPRESSION OF LAG-3 IN THE T CELLS OF PERIPHERAL BLOOD OF 50 HEALTHY CONTROLS AND 50 PATIENTS WITH CHRONIC OSTEOMYELITIS BY FLOW CYTOMETRY. CLINICAL DATA WERE ANALYZED TO DETERMINE THE CORRELATION BETWEEN INFLAMMATION INDEX AND LAG-3 EXPRESSION. MOREOVER, WE ISOLATED THE CD4(+) T CELLS FROM HEALTHY CONTROLS AND CHRONIC OSTEOMYELITIS PATIENTS TO COMPARE CELL PROLIFERATION AND IFN-GAMMA PRODUCTION. CHROMATIN IMMUNOPRECIPITATION ASSAYS WERE UTILIZED TO ANALYZE THE EPIGENETIC MODIFICATION ON LAG-3 EXPRESSION IN T CELLS. WE FOUND THAT LAG-3 WAS SIGNIFICANTLY INCREASED IN THE T CELLS OF PERIPHERAL BLOOD FROM CHRONIC OSTEOMYELITIS PATIENTS. SUBSEQUENTLY, CLINICAL DATA ANALYSIS SUGGESTED THAT THE HIGHER EXPRESSION OF LAG-3 WAS ASSOCIATED WITH SEVERER INFLAMMATION SITUATION. CONSISTENTLY, LAG-3(+)CD4(+) T CELLS EXHIBITED IMPAIRED CELL PROLIFERATION AND IFN-GAMMA SECRETION. DEREGULATION OF HISTONE METHYLATION MEDIATED THE INCREASE OF LAG-3(+) T CELLS DURING CHRONIC OSTEOMYELITIS. TAKEN TOGETHER, OUR STUDY DEMONSTRATES THE INCREASE OF LAG-3(+) T CELLS AND ITS IMMUNE REGULATORY ROLES IN CHRONIC OSTEOMYELITIS PROGRESSION, SUGGESTING NEW MECHANISMS AND POTENTIAL THERAPEUTIC TARGETS FOR CHRONIC OSTEOMYELITIS. 2017 11 3070 29 GENOME-WIDE DNA METHYLATION PROFILING IN CD8 T-CELLS AND GAMMA DELTA T-CELLS OF ASIAN INDIAN PATIENTS WITH TAKAYASU ARTERITIS. BACKGROUND: TAKAYASU'S ARTERITIS (TA) IS A CHRONIC INFLAMMATORY DISEASE THAT AFFECTS AORTA AND ITS MAIN BRANCHES AT THEIR ORIGIN. GENETIC, PATHOLOGICAL AND FUNCTIONAL STUDIES HAVE SHOWN THAT CD8 AND GAMMA DELTA (GAMMA/DELTA) T-LYMPHOCYTES ARE INVOLVED IN INFLAMMATORY PROCESSES IN AFFECTED REGIONS OF ARTERIES CAUSING VASCULAR DAMAGE. THE MOLECULAR FUNCTION OF THESE LYMPHOCYTES REMAINS UNCLEAR AND CURRENTLY NO EPIGENETIC STUDIES ARE AVAILABLE IN TA. WE PRIMARILY PERFORMED GENOME WIDE METHYLATION ANALYSIS IN CD8 T CELLS AND GAMMADELTA T CELLS OF PATIENTS WITH TA AND COMPARED WITH HEALTHY CONTROLS. METHODS: WE RECRUITED 12 SUBJECTS IN EACH GROUP NAMELY TA PATIENT AND HEALTHY CONTROLS. BLOOD SAMPLES WERE COLLECTED AFTER OBTAINING INFORMED WRITTEN CONSENT. CD8 T CELLS AND GAMMADELTA T CELLS WERE SEPARATED FROM WHOLE BLOOD. DNA EXTRACTED FROM THESE CELLS AND WERE SUBJECTED TO BISULFITE TREATMENT. FINALLY, BISULFITE TREATED DNA WAS LOADED IN INFINIUM METHYLATION EPIC ARRAY. BIOINFORMATICS ANALYSIS WAS USED TO IDENTIFY DIFFERENTIAL METHYLATION REGIONS WHICH WERE THEN MAPPED TO GENES. RESULTS: INTERLEUKIN (IL)-32 AND LYMPHOTOXIN-A WERE GENES SIGNIFICANTLY HYPOMETHYLATED IN CD8 T-CELLS. ANTI-INFLAMMATORY CYTOKINE GENES, IL-10, IL-1RN AND IL-27 WERE HYPOMETHYLATED IN GAMMADELTA T CELLS OF TA PATIENTS AS COMPARED TO HEALTHY CONTROLS. GENE ENRICHMENT ANALYSIS USING GENE ONTOLOGY (GO) DATABASE AND KYOTO ENCYCLOPAEDIA OF GENES AND GENOMES (KEGG) IDENTIFIED THAT GENES INVOLVED IN T-CELL RECEPTOR SIGNALLING PATHWAYS WERE HYPOMETHYLATED IN CD8 T-CELLS AND HYPERMETHYLATED IN GAMMADELTA T CELLS OF TA PATIENTS. CONCLUSION: CD8 T-CELLS MIGHT PLAY A MAJOR ROLE IN IMMUNOPATHOGENESIS OF INFLAMMATION IN TA, WHEREAS GAMMADELTA T CELLS MAY PLAY A REGULATORY ROLE. 2022 12 1061 43 CLINICAL REMISSION OF SIGHT-THREATENING NON-INFECTIOUS UVEITIS IS CHARACTERIZED BY AN UPREGULATION OF PERIPHERAL T-REGULATORY CELL POLARIZED TOWARDS T-BET AND TIGIT. BACKGROUND: NON-INFECTIOUS UVEITIS CAN CAUSE CHRONIC RELAPSING AND REMITTING OCULAR INFLAMMATION, WHICH MAY REQUIRE HIGH DOSE SYSTEMIC IMMUNOSUPPRESSION TO PREVENT SEVERE SIGHT LOSS. IT HAS BEEN CLASSICALLY DESCRIBED AS AN AUTOIMMUNE DISEASE, MEDIATED BY PRO-INFLAMMATORY TH1 AND TH17 T-CELL SUBSETS. STUDIES SUGGEST THAT NATURAL IMMUNOSUPPRESSIVE CD4(+)CD25(+)FOXP3(+) T-REGULATORY CELLS (TREGS) ARE INVOLVED IN RESOLUTION OF INFLAMMATION AND MAY BE INVOLVED IN THE MAINTENANCE OF CLINICAL REMISSION. OBJECTIVE: TO INVESTIGATE WHETHER THERE IS A PERIPHERAL BLOOD IMMUNOREGULATORY PHENOTYPE ASSOCIATED WITH CLINICAL REMISSION OF SIGHT-THREATENING NON-INFECTIOUS UVEITIS BY COMPARING PERIPHERAL BLOOD LEVELS OF TREG, TH1, AND TH17, AND ASSOCIATED DNA METHYLATION AND CYTOKINE LEVELS IN PATIENTS WITH ACTIVE UVEITIC DISEASE, CONTROL SUBJECTS AND PATIENTS (WITH PREVIOUSLY ACTIVE DISEASE) IN CLINICAL REMISSION INDUCED BY IMMUNOSUPPRESSIVE DRUGS. METHODS: ISOLATED PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMC) FROM PERIPHERAL BLOOD SAMPLES FROM PROSPECTIVELY RECRUITED SUBJECTS WERE ANALYZED BY FLOW CYTOMETRY FOR CD3, CD4, FOXP3, TIGIT, T-BET, AND RELATED ORPHAN RECEPTOR GAMMAT. EPIGENETIC DNA METHYLATION LEVELS OF FOXP3 TREG-SPECIFIC DEMETHYLATED REGION (TSDR), FOXP3 PROMOTER, TBX21, RORC2, AND TIGIT LOCI WERE DETERMINED IN CRYOPRESERVED PBMC USING A NEXT-GENERATION SEQUENCING APPROACH. RELATED CYTOKINES WERE MEASURED IN BLOOD SERA. FUNCTIONAL SUPPRESSIVE CAPACITY OF TREG WAS ASSESSED USING T-CELL PROLIFERATION ASSAYS. RESULTS: FIFTY PATIENTS WITH UVEITIS (INTERMEDIATE, POSTERIOR, AND PANUVEITIS) AND 10 CONTROL SUBJECTS WERE RECRUITED. THE FREQUENCY OF CD4(+)CD25(+)FOXP3(+) TREG, TIGIT(+) TREG, AND T-BET(+) TREG AND THE RATIO OF TREG TO TH1 WERE SIGNIFICANTLY HIGHER IN REMISSION PATIENTS COMPARED WITH PATIENTS WITH ACTIVE UVEITIC DISEASE; AND TIGIT(+) TREGS WERE A SIGNIFICANT PREDICTOR OF CLINICAL REMISSION. TREG FROM PATIENTS IN CLINICAL REMISSION DEMONSTRATED A HIGH LEVEL OF IN VITRO SUPPRESSIVE FUNCTION COMPARED WITH TREG FROM CONTROL SUBJECTS AND FROM PATIENTS WITH UNTREATED ACTIVE DISEASE. PBMC FROM PATIENTS IN CLINICAL REMISSION HAD SIGNIFICANTLY LOWER METHYLATION LEVELS AT THE FOXP3 TSDR, FOXP3 PROMOTER, AND TIGIT LOCI AND HIGHER LEVELS AT RORC LOCI THAN THOSE WITH ACTIVE DISEASE. CLINICAL REMISSION WAS ALSO ASSOCIATED WITH SIGNIFICANTLY HIGHER SERUM LEVELS OF TRANSFORMING GROWTH FACTOR BETA AND IL-10, WHICH POSITIVELY CORRELATED WITH TREG LEVELS, AND LOWER SERUM LEVELS OF IFNGAMMA, IL-17A, AND IL-22 COMPARED WITH PATIENTS WITH ACTIVE DISEASE. CONCLUSION: CLINICAL REMISSION OF SIGHT-THREATENING NON-INFECTIOUS UVEITIS HAS AN IMMUNOREGULATORY PHENOTYPE CHARACTERIZED BY UPREGULATION OF PERIPHERAL TREG, POLARIZED TOWARD T-BET AND TIGIT. THESE FINDINGS MAY ASSIST WITH INDIVIDUALIZED THERAPY OF UVEITIS, BY INFORMING WHETHER DRUG THERAPY HAS INDUCED PHENOTYPICALLY STABLE TREG ASSOCIATED WITH LONG-TERM CLINICAL REMISSION. 2018 13 2242 23 EPIGENETIC MODULATION OF CD8(+) T CELL FUNCTION IN LENTIVIRUS INFECTIONS: A REVIEW. CD8(+) T CELLS ARE CRITICAL FOR CONTROLLING VIREMIA DURING HUMAN IMMUNODEFICIENCY VIRUS (HIV) INFECTION. THESE CELLS PRODUCE CYTOLYTIC FACTORS AND ANTIVIRAL CYTOKINES THAT ELIMINATE VIRALLY- INFECTED CELLS. DURING THE CHRONIC PHASE OF HIV INFECTION, CD8(+) T CELLS PROGRESSIVELY LOSE THEIR PROLIFERATIVE CAPACITY AND ANTIVIRAL FUNCTIONS. THESE DYSFUNCTIONAL CELLS ARE UNABLE TO CLEAR THE PRODUCTIVELY INFECTED AND REACTIVATED CELLS, REPRESENTING A ROADBLOCK IN HIV CURE. THEREFORE, MECHANISMS TO UNDERSTAND CD8(+) T CELL DYSFUNCTION AND STRATEGIES TO BOOST CD8(+) T CELL FUNCTION NEED TO BE INVESTIGATED. USING THE FELINE IMMUNODEFICIENCY VIRUS (FIV) MODEL FOR LENTIVIRAL PERSISTENCE, WE HAVE DEMONSTRATED THAT CD8(+) T CELLS EXHIBIT EPIGENETIC CHANGES SUCH AS DNA DEMETHYLATION DURING THE COURSE OF INFECTION AS COMPARED TO UNINFECTED CATS. WE HAVE ALSO DEMONSTRATED THAT LENTIVIRUS-ACTIVATED CD4(+)CD25(+) T REGULATORY CELLS INDUCE FORKHEAD BOX P3 (FOXP3) EXPRESSION IN VIRUS-SPECIFIC CD8(+) T CELL TARGETS, WHICH BINDS THE INTERLEUKIN (IL)-2, TUMOR NECROSIS FACTOR (TNF)-&ALPHA;, AND INTERFERON (IFN)-&GAMMA; PROMOTERS IN THESE CD8(+) T CELLS. FINALLY, WE HAVE REPORTED THAT EPIGENETIC MODULATION REDUCES FOXP3 BINDING TO THESE PROMOTER REGIONS. THIS REVIEW COMPARES AND CONTRASTS OUR CURRENT UNDERSTANDING OF CD8(+) T CELL EPIGENETICS AND MECHANISMS OF LYMPHOCYTE SUPPRESSION DURING THE COURSE OF LENTIVIRAL INFECTION FOR TWO ANIMAL MODELS, FIV AND SIMIAN IMMUNODEFICIENCY VIRUS (SIV). 2018 14 5732 25 SMAD4 TGF-BETA-INDEPENDENT FUNCTION PRECONDITIONS NAIVE CD8+ T CELLS TO PREVENT SEVERE CHRONIC INTESTINAL INFLAMMATION. SMAD4, A MEDIATOR OF TGF-BETA SIGNALING, PLAYS AN IMPORTANT ROLE IN T CELLS TO PREVENT INFLAMMATORY BOWEL DISEASE (IBD). HOWEVER, THE PRECISE MECHANISMS UNDERLYING THIS CONTROL REMAIN ELUSIVE. USING BOTH GENETIC AND EPIGENETIC APPROACHES, WE REVEALED AN UNEXPECTED MECHANISM BY WHICH SMAD4 PREVENTS NAIVE CD8+ T CELLS FROM BECOMING PATHOGENIC FOR THE GUT. PRIOR TO THE ENGAGEMENT OF THE TGF-BETA RECEPTOR, SMAD4 RESTRAINS THE EPIGENETIC, TRANSCRIPTIONAL, AND FUNCTIONAL LANDSCAPE OF THE TGF-BETA SIGNATURE IN NAIVE CD8+ T CELLS. MECHANISTICALLY, PRIOR TO TGF-BETA SIGNALING, SMAD4 BINDS TO PROMOTERS AND ENHANCERS OF SEVERAL TGF-BETA TARGET GENES, AND BY REGULATING HISTONE DEACETYLATION, SUPPRESSES THEIR EXPRESSION. CONSEQUENTLY, REGARDLESS OF A TGF-BETA SIGNAL, SMAD4 LIMITS THE EXPRESSION OF TGF-BETA NEGATIVE FEEDBACK LOOP GENES, SUCH AS SMAD7 AND SKI, AND LIKELY CONDITIONS CD8+ T CELLS FOR THE IMMUNOREGULATORY EFFECTS OF TGF-BETA. IN ADDITION, SMAD4 ABLATION CONFERRED NAIVE CD8+ T CELLS WITH BOTH A SUPERIOR SURVIVAL CAPACITY, BY ENHANCING THEIR RESPONSE TO IL-7, AS WELL AS AN ENHANCED CAPACITY TO BE RETAINED WITHIN THE INTESTINAL EPITHELIUM, BY PROMOTING THE EXPRESSION OF ITGAE, WHICH ENCODES THE INTEGRIN CD103. ACCUMULATION, EPITHELIAL RETENTION, AND ESCAPE FROM TGF-BETA CONTROL ELICITED CHRONIC MICROBIOTA-DRIVEN CD8+ T CELL ACTIVATION IN THE GUT. HENCE, IN A TGF-BETA-INDEPENDENT MANNER, SMAD4 IMPRINTS A PROGRAM THAT PRECONDITIONS NAIVE CD8+ T CELL FATE, PREVENTING IBD. 2022 15 3454 34 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 16 1472 32 DISTINCT MECHANISMS REGULATE IL1B GENE TRANSCRIPTION IN LYMPHOID CD4 T CELLS AND MONOCYTES. INTERLEUKIN 1BETA IS A PRO-INFLAMMATORY CYTOKINE IMPORTANT FOR BOTH NORMAL IMMUNE RESPONSES AND CHRONIC INFLAMMATORY DISEASES. THE REGULATION OF THE 31 KDA PROIL-1BETA PRECURSOR CODED BY THE IL1B GENE HAS BEEN EXTENSIVELY STUDIED IN MYELOID CELLS, BUT NOT IN LYMPHOID-DERIVED CD4 T CELLS. SURPRISINGLY, WE FOUND THAT SOME CD4 T CELL SUBSETS EXPRESS HIGHER LEVELS OF PROIL-1BETA THAN UNSTIMULATED MONOCYTES, DESPITE RELATIVELY LOW IL1B MRNA LEVELS. WE OBSERVED A SIGNIFICANT INCREASE IN IL1B TRANSCRIPTION AND TRANSLATION IN CD4 T CELLS UPON EX VIVO CD3/CD28 ACTIVATION, AND A SIMILAR ELEVATION IN THE CCR5+ EFFECTOR MEMORY POPULATION COMPARED TO CCR5- T CELLS IN VIVO. THE RAPID AND VIGOROUS INCREASE IN IL1B GENE TRANSCRIPTION FOR STIMULATED MONOCYTES HAS PREVIOUSLY BEEN ASSOCIATED WITH THE PRESENCE OF SPI-1/PU.1 (SPI1), A MYELOID-LINEAGE TRANSCRIPTION FACTOR, PRE-BOUND TO THE PROMOTER. IN THE CASE OF CD4 T CELLS, THIS INCREASE OCCURRED DESPITE THE LACK OF DETECTABLE SPI1 AT THE IL1B PROMOTER. ADDITIONALLY, WE FOUND ALTERED EPIGENETIC REGULATION OF THE IL1B LOCUS IN CD3/CD28-ACTIVATED CD4 T CELLS. UNLIKE MONOCYTES, ACTIVATED CD4 T CELLS POSSESS BIVALENT H3K4ME3+/H3K27ME3+ NUCLEOSOME MARKS AT THE IL1B PROMOTER, REFLECTING LOW TRANSCRIPTIONAL ACTIVITY. THESE RESULTS SUPPORT A MODEL IN WHICH THE IL1B GENE IN CD4 T CELLS IS TRANSCRIBED FROM A LOW-ACTIVITY BIVALENT PROMOTER INDEPENDENT OF SPI1. ACCUMULATED CYTOPLASMIC PROIL-1BETA MAY ULTIMATELY BE CLEAVED TO MATURE 17 KDA BIOACTIVE IL-1BETA, REGULATING T CELL POLARIZATION AND PATHOGENIC CHRONIC INFLAMMATION. 2018 17 5704 28 SINGLE-CELL RNA-SEQ REVEALS TOX AS A KEY REGULATOR OF CD8(+) T CELL PERSISTENCE IN CHRONIC INFECTION. PROGENITOR-LIKE CD8(+) T CELLS MEDIATE LONG-TERM IMMUNITY TO CHRONIC INFECTION AND CANCER AND RESPOND POTENTLY TO IMMUNE CHECKPOINT BLOCKADE. THESE CELLS SHARE TRANSCRIPTIONAL REGULATORS WITH MEMORY PRECURSOR CELLS, INCLUDING T CELL-SPECIFIC TRANSCRIPTION FACTOR 1 (TCF1), BUT IT IS UNCLEAR WHETHER THEY ADOPT DISTINCT PROGRAMS TO ADAPT TO THE IMMUNOSUPPRESSIVE ENVIRONMENT. BY COMPARING THE SINGLE-CELL TRANSCRIPTOMES AND EPIGENETIC PROFILES OF CD8(+) T CELLS RESPONDING TO ACUTE AND CHRONIC VIRAL INFECTIONS, WE FOUND THAT PROGENITOR-LIKE CD8(+) T CELLS BECAME DISTINCT FROM MEMORY PRECURSOR CELLS BEFORE THE PEAK OF THE T CELL RESPONSE. WE DISCOVERED A COEXPRESSION GENE MODULE CONTAINING TOX THAT EXHIBITED HIGHER TRANSCRIPTIONAL ACTIVITY ASSOCIATED WITH MORE ABUNDANT ACTIVE HISTONE MARKS IN PROGENITOR-LIKE CELLS THAN MEMORY PRECURSOR CELLS. MOREOVER, THYMOCYTE SELECTION-ASSOCIATED HIGH MOBILITY GROUP BOX PROTEIN TOX (TOX) PROMOTED THE PERSISTENCE OF ANTIVIRAL CD8(+) T CELLS AND WAS REQUIRED FOR THE PROGRAMMING OF PROGENITOR-LIKE CD8(+) T CELLS. THUS, LONG-TERM CD8(+) T CELL IMMUNITY TO CHRONIC VIRAL INFECTION REQUIRES UNIQUE TRANSCRIPTIONAL AND EPIGENETIC PROGRAMS ASSOCIATED WITH THE TRANSCRIPTION FACTOR TOX. 2019 18 2185 32 EPIGENETIC MECHANISMS UNDERLYING HIV-INFECTION INDUCED SUSCEPTIBILITY OF CD4+ T CELLS TO ENHANCED ACTIVATION-INDUCED FASL EXPRESSION AND CELL DEATH. BACKGROUND: CHRONIC IMMUNE ACTIVATION AND CD4 T CELL DEPLETION ARE SIGNIFICANT PATHOGENIC FEATURES OF HIV INFECTION. EXPRESSION OF FAS LIGAND (FASL), A KEY MEDIATOR OF ACTIVATION-INDUCED CELL DEATH IN T CELLS, IS ELEVATED IN PEOPLE LIVING WITH HIV-1 INFECTION (PLWH). HOWEVER, THE EPIGENETIC MECHANISMS UNDERLYING THE ENHANCED INDUCTION OF FASL EXPRESSION IN CD4 T LYMPHOCYTES IN PLWH ARE NOT COMPLETELY ELUCIDATED. HENCE, THE CURRENT WORK EXAMINED THE EFFECT OF HIV INFECTION ON FASL PROMOTER-ASSOCIATED HISTONE MODIFICATIONS AND TRANSCRIPTIONAL REGULATION IN CD4 T LYMPHOCYTES IN PLWH. METHOD: FLOW CYTOMETRIC ANALYSIS WAS PERFORMED TO EXAMINE THE FAS-FASL EXPRESSION ON TOTAL CD4 T CELLS AND NAIVE/MEMORY CD4 T CELL SUBSETS. EPIGENETIC FASL PROMOTER HISTONE MODIFICATIONS WERE INVESTIGATED BY CHROMATIN IMMUNOPRECIPITATION-QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION ANALYSIS USING FRESHLY ISOLATED TOTAL CD4 T LYMPHOCYTES FROM HIV-1 INFECTED AND NONINFECTED INDIVIDUALS. RESULTS: ALL NAIVE/MEMORY CD4 T CELL SUBSETS FROM PLWH SHOWED MARKEDLY GREATER FREQUENCY OF FASL EXPRESSION. NOTABLY, EXAMINATION OF FUNCTIONAL OUTCOME OF FASL/FAS CO-EXPRESSION DEMONSTRATED THE PREFERENTIAL SUSCEPTIBILITY OF TCM AND TEM SUBSETS TO ACTIVATION-INDUCED APOPTOSIS. IMPORTANTLY, THESE CD4 T CELLS COLLECTIVELY DEMONSTRATED A DISTINCT FASL PROMOTER HISTONE PROFILE INVOLVING A COORDINATED CROSS-TALK BETWEEN HISTONE H3 MODIFICATIONS LEADING TO ENHANCED FASL GENE EXPRESSION. SPECIFICALLY, LEVELS OF TRANSCRIPTIONALLY PERMISSIVE HISTONE H3K4-TRIMETHYLATION (H3K4ME3) AND HISTONE H3K9-ACETYLATION (H3K9AC) WERE INCREASED, WITH A CONCOMITANT DECREASE IN THE REPRESSIVE H3K9-TRIMETHYLATION (H3K9ME3). CONCLUSION: THE PRESENT WORK DEMONSTRATES THAT EPIGENETIC MECHANISMS INVOLVING PROMOTER-HISTONE MODIFICATIONS REGULATE TRANSCRIPTIONAL COMPETENCE AND FASL EXPRESSION IN CD4 T CELLS FROM PLWH AND RENDER THEM SUSCEPTIBLE TO ACTIVATION-INDUCED CELL DEATH. 2021 19 6231 30 THE LONG NONCODING RNA MEG3 AND ITS TARGET MIR-147 REGULATE JAK/STAT PATHWAY IN ADVANCED CHRONIC MYELOID LEUKEMIA. BACKGROUND: LONG NON-CODING (LNC) RNAS PLAYS AN IMPORTANT ROLE IN CHRONIC MYELOID LEUKEMIA (CML). IN THIS STUDY, WE AIMED TO UNCOVER THE MECHANISM OF THE LNCRNA MATERNALLY EXPRESSED 3 (MEG3) AND ITS TARGET MICRORNA-147 (MIR-147) IN CML. METHODS: SIXTY CML PATIENTS AND 10 HEALTHY DONORS WERE INCLUDED IN THE STUDY. THE METHYLATION OF MEG3 AND MIR-147 PROMOTER WAS DETERMINED BY METHYLATION-SPECIFIC PCR. THE RELATIONSHIP OF MEG3 AND MIR-147 WAS EXPLORED BY LUCIFERASE ASSAY. THE INTERACTIONS OF PROTEINS WERE STUDIED BY RNA PULL-DOWN ASSAY, RNA IMMUNOPRECIPITATION AND CO-IMMUNOPRECIPITATION. FINDINGS: PATIENTS IN ACCELERATED PHASE CML (CML-AP) AND BLAST PHASE CML (CML-BP) SHOWED LOWER EXPRESSIONS OF MEG3 AND MIR-147 AND HIGHER EXPRESSIONS OF DNMT1, DNMT3B, MBD2, MECP2 AND HDAC1 COMPARED TO THE CONTROLS. THESE PATIENTS ALSO SHOWED A HIGHER DEGREE OF METHYLATION OF MEG3 AND MIR-147 WHILE THERE WAS A REDUCTION AFTER CHIDAMIDE TREATMENT. FURTHERMORE, THE OVEREXPRESSION OF MEG3 AND MIR-147 INHIBITED CELL PROLIFERATION BOTH IN VIVO AND IN VITRO, PROMOTED APOPTOSIS AND DECREASED THE EXPRESSIONS OF DNMT1, DNMT3A, DNMT3B, MBD2, HDAC1 AND MECP2. WE ALSO FOUND MEG3 INTERACTED WITH DNMT1, JAK2, STAT3, HDAC1, AND TYK2, AND JAK2 WAS BOUND TO STAT3, STAT5 AND MYC. MORE INTERESTINGLY, JAK2 WAS BOUND TO TYK2 BY THE BRIDGE OF MEG3. INTERPRETATION: LNCRNA MEG3 AND ITS TARGET MIR-147 MAY SERVE AS A NOVEL THERAPEUTIC TARGET FOR CML BLAST CRISIS, AND CHIDAMIDE MIGHT HAVE A POTENTIAL CLINICAL APPLICATION IN TREATING CML BLAST CRISIS. 2018 20 1994 35 EPIGENETIC AND GENE EXPRESSION ALTERATIONS OF FOXP3 IN THE T CELLS OF EAE MOUSE MODEL OF MULTIPLE SCLEROSIS. MULTIPLE SCLEROSIS (MS) IS A CHRONIC AUTOIMMUNE DISEASE WITH DEMYELINATION AND NEURODEGENERATION OF THE CENTRAL NERVOUS SYSTEM. IT HAS BEEN SHOWN THAT THE REGULATORY T (TREG) CELLS ARE RESPONSIBLE FOR MAINTAINING TOLERANCE TO SELF-ANTIGENS AND CAN SUPPRESS THE AUTOIMMUNE PROCESS IN SEVERAL ANIMAL MODELS SUCH AS EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS (EAE), A MOUSE MODEL OF MS. RECENT BASIC STUDIES HAVE DEMONSTRATED THAT FORKHEAD BOX P (FOXP3) AND BTB DOMAIN AND CNC HOMOLOG 2 (BACH2) ARE THE MASTER TRANSCRIPTION FACTORS OF THESE CELLS PLAYING A PIVOTAL ROLE IN THE POLARIZATION OF NAIVE T CELLS INTO TREG CELLS. IN THE CURRENT STUDY, THE EXPRESSION OF FOXP3 AND BACH2 GENES AND FOXP3 PROMOTER METHYLATION WERE EVALUATED IN T CELLS OF THE EAE-INDUCED MICE. THE RESULTS OF THIS STUDY SHOWED A PROMINENT AND SIGNIFICANT HYPERMETHYLATION OF THE FOXP3 GENE PROMOTER IN THE EAE-INDUCED MICE COMPARED TO THE SHAM AND CONTROL GROUPS. THE EXPRESSION OF FOXP3 AND BACH2 GENES WAS SIGNIFICANTLY DECREASED IN THE EAE GROUP IN COMPARISON WITH THE SHAM AND CONTROL GROUPS. THIS STUDY SUGGESTS THAT THE EPIGENETIC MODIFICATION OF FOXP3 GENE IS INVOLVED IN THE PATHOGENESIS OF EAE AND THIS COULD BE IMPORTANT IN THERAPY IN AN APPROPRIATE AND LOGICAL STATEMENT. 2017