1 2270 108 EPIGENETIC QUANTIFICATION OF IMMUNOSENESCENT CD8(+) TEMRA CELLS IN HUMAN BLOOD. AGE-RELATED CHANGES IN HUMAN T-CELL POPULATIONS ARE IMPORTANT CONTRIBUTORS TO IMMUNOSENESCENCE. IN PARTICULAR, TERMINALLY DIFFERENTIATED CD8(+) EFFECTOR MEMORY CD45RA(+) TEMRA CELLS AND THEIR SUBSETS HAVE CHARACTERISTICS OF CELLULAR SENESCENCE, ACCUMULATE IN OLDER INDIVIDUALS, AND ARE INCREASED IN AGE-RELATED CHRONIC INFLAMMATORY DISEASES. IN A DETAILED T-CELL PROFILING AMONG INDIVIDUALS OVER 65 YEARS OF AGE, WE FOUND A HIGH INTERINDIVIDUAL VARIATION AMONG CD8(+) TEMRA POPULATIONS. CD8(+) TEMRA PROPORTIONS CORRELATED POSITIVELY WITH CYTOMEGALOVIRUS (CMV) ANTIBODY LEVELS, HOWEVER, NOT WITH THE CHRONOLOGICAL AGE. IN THE ANALYSIS OF OVER 90 INFLAMMATION PROTEINS, WE IDENTIFIED PLASMA TRANCE/RANKL LEVELS TO ASSOCIATE WITH SEVERAL DIFFERENTIATED T-CELL POPULATIONS, INCLUDING CD8(+) TEMRA AND ITS CD28(-) SUBSETS. GIVEN THE STRONG POTENTIAL OF CD8(+) TEMRA CELLS AS A BIOMARKER FOR IMMUNOSENESCENCE, WE USED DEEP-AMPLICON BISULFITE SEQUENCING TO MATCH THEIR FREQUENCIES IN FLOW CYTOMETRY WITH CPG SITE METHYLATION LEVELS AND DEVELOPED A COMPUTATIONAL MODEL TO PREDICT CD8(+) TEMRA CELL PROPORTIONS FROM WHOLE BLOOD GENOMIC DNA. OUR FINDINGS CONFIRM THE ASSOCIATION OF CD8(+) TEMRA AND ITS SUBSETS WITH CMV INFECTION AND PROVIDE A NOVEL TOOL FOR THEIR HIGH THROUGHPUT EPIGENETIC QUANTIFICATION AS A BIOMARKER OF IMMUNOSENESCENCE. 2022 2 1763 25 EARLY TRANSCRIPTIONAL AND EPIGENETIC DIVERGENCE OF CD8+ T CELLS RESPONDING TO ACUTE VERSUS CHRONIC INFECTION. DURING A MICROBIAL INFECTION, RESPONDING CD8+ T CELLS GIVE RISE TO EFFECTOR CELLS THAT PROVIDE ACUTE HOST DEFENSE AND MEMORY CELLS THAT PROVIDE SUSTAINED PROTECTION. AN ALTERNATIVE OUTCOME IS EXHAUSTION, A STATE OF T CELL DYSFUNCTION THAT OCCURS IN THE CONTEXT OF CHRONIC INFECTIONS AND CANCER. ALTHOUGH IT IS EVIDENT THAT EXHAUSTED CD8+ T (TEX) CELLS ARE PHENOTYPICALLY AND MOLECULARLY DISTINCT FROM EFFECTOR AND MEMORY CD8+ T CELLS, THE FACTORS REGULATING THE EARLIEST EVENTS IN THE DIFFERENTIATION PROCESS OF TEX CELLS REMAIN INCOMPLETELY UNDERSTOOD. HERE, WE PERFORMED SINGLE-CELL RNA-SEQUENCING AND SINGLE-CELL ATAC-SEQUENCING OF CD8+ T CELLS RESPONDING TO LCMV-ARMSTRONG (LCMV-ARM) OR LCMV-CLONE 13 (LCMV-CL13), WHICH RESULT IN ACUTE OR CHRONIC INFECTIONS, RESPECTIVELY. COMPARED TO CD8+ T CELLS THAT HAD UNDERGONE THEIR FIRST DIVISION IN RESPONSE TO LCMV-ARM (DIV1ARM) CELLS, CD8+ T CELLS THAT HAD UNDERGONE THEIR FIRST DIVISION IN RESPONSE TO LCMV-CL13 (DIV1CL13) EXPRESSED HIGHER LEVELS OF GENES ENCODING TRANSCRIPTION FACTORS PREVIOUSLY ASSOCIATED WITH EXHAUSTION, ALONG WITH HIGHER LEVELS OF EZH2, THE CATALYTIC COMPONENT OF THE POLYCOMB REPRESSIVE COMPLEX 2 (PRC2) COMPLEX, WHICH MEDIATES EPIGENETIC SILENCING. MODULATION OF EZH2 RESULTED IN ALTERED EXPRESSION OF EXHAUSTION-ASSOCIATED MOLECULES BY CD8+ T CELLS RESPONDING TO LCMV-CL13, THOUGH THE SPECIFIC CELLULAR AND INFECTIOUS CONTEXTS, RATHER THAN SIMPLY THE LEVEL OF EZH2 EXPRESSION, LIKELY DETERMINE THE EVENTUAL OUTCOME. TAKEN TOGETHER, THESE FINDINGS SUGGEST THAT THE DIFFERENTIATION PATHS OF CD8+ T CELLS RESPONDING TO ACUTE VERSUS CHRONIC INFECTIONS MAY DIVERGE EARLIER THAN PREVIOUSLY APPRECIATED. 2023 3 217 33 ACUTE EXERCISE INCREASES THE EXPRESSION OF KIR2DS4 BY PROMOTER DEMETHYLATION IN NK CELLS. POSITIVE EFFECTS OF EXERCISE ON CANCER PREVENTION AND PROGRESSION HAVE BEEN PROPOSED TO BE MEDIATED BY STIMULATING NATURAL KILLER (NK) CELLS. BECAUSE NK CELL RECEPTORS ARE REGULATED BY EPIGENETIC MODIFICATIONS, WE INVESTIGATED WHETHER ACUTE AEROBIC EXERCISE AND TRAINING CHANGE PROMOTER DNA METHYLATION AND GENE EXPRESSION OF THE ACTIVATING KIR2DS4 AND THE INHIBITING KIR3DL1 GENE. SIXTEEN HEALTHY WOMEN (50-60 YEARS) PERFORMED A GRADED EXERCISE TEST (GXT) AND WERE RANDOMIZED INTO EITHER A PASSIVE CONTROL GROUP OR AN INTERVENTION GROUP PERFORMING A FOUR-WEEK ENDURANCE EXERCISE INTERVENTION. BLOOD SAMPLES (PRE-, POST-GXT AND POST-TRAINING) WERE USED FOR ISOLATION OF DNA/RNA OF NK CELLS TO ASSESS DNA PROMOTER METHYLATION BY TARGETED DEEP-AMPLICON SEQUENCING AND GENE EXPRESSION BY QRT-PCR. POTENTIAL CHANGES IN NK CELL SUBSETS WERE DETERMINED BY FLOW CYTOMETRY. ACUTE AND CHRONIC EXERCISE DID NOT PROVOKE SIGNIFICANT ALTERATIONS OF NK CELL PROPORTIONS. PROMOTER METHYLATION DECREASED AND GENE EXPRESSION INCREASED FOR KIR2DS4 AFTER ACUTE EXERCISE. A HIGH GENE EXPRESSION CORRELATED WITH A LOW METHYLATION OF CPGS THAT WERE ALTERED BY ACUTE EXERCISE. CHRONIC EXERCISE RESULTED IN A MINOR DECREASE OF DNA METHYLATION AND DID NOT ALTER GENE EXPRESSION. ACUTE EXERCISE PROVOKES EPIGENETIC MODIFICATIONS, AFFECTING THE BALANCE BETWEEN THE ACTIVATING KIR2DS4 AND THE INHIBITING KIR3DL1, WITH POTENTIAL BENEFITS ON NK CELL FUNCTION. 2019 4 6186 24 THE IMPACT OF HIV INFECTION ON THE FREQUENCIES, FUNCTION, SPATIAL LOCALIZATION AND HETEROGENEITY OF T FOLLICULAR REGULATORY CELLS (TFRS) WITHIN HUMAN LYMPH NODES. BACKGROUND: HIV ERADICATION EFFORTS HAVE BEEN UNSUCCESSFUL PARTLY DUE TO VIRUS PERSISTENCE IN IMMUNE SANCTUARY SITES SUCH AS GERMINAL CENTRES WITHIN LYMPH NODE (LN) TISSUES. RECENT EVIDENCE SUGGESTS THAT LNS HARBOUR A NOVEL SUBSET OF REGULATORY T CELLS, TERMED FOLLICULAR REGULATORY T CELLS (TFRS), BUT THEIR ROLE IN HIV PATHOGENESIS IS NOT FULLY ELUCIDATED. RESULTS: PAIRED EXCISIONAL LN AND PERIPHERAL BLOOD SAMPLES OBTAINED FROM 20 HIV-UNINFECTED AND 31 HIV-INFECTED TREATED AND 7 CHRONIC UNTREATED, WERE USED TO DETERMINE IF AND HOW HIV INFECTION MODULATE FREQUENCIES, FUNCTION AND SPATIAL LOCALIZATION OF TFRS WITHIN LN TISSUES. IMAGING STUDIES SHOWED THAT MOST TFRS ARE LOCALIZED IN EXTRA-FOLLICULAR REGIONS. CO-CULTURE ASSAYS SHOWED TFRS SUPPRESSION OF TFH HELP TO B CELLS. IMPORTANTLY, EPIGENETIC AND TRANSCRIPTIONAL STUDIES IDENTIFIED DPP4 AND FCRL3 AS NOVEL PHENOTYPIC MARKERS THAT DEFINE FOUR FUNCTIONALLY DISTINCT TFR SUBPOPULATIONS IN HUMAN LNS REGARDLESS OF HIV STATUS. IMAGING STUDIES CONFIRMED THE REGULATORY PHENOTYPE OF DPP4(+)TFRS. CONCLUSION: TOGETHER THESE STUDIES DESCRIBE TFRS DYNAMIC CHANGES DURING HIV INFECTION AND REVEAL PREVIOUSLY UNDERAPPRECIATED TFR HETEROGENEITY WITHIN HUMAN LNS. 2022 5 1121 22 COMPARISON OF EPIGENETIC PROFILES OF HUMAN ORAL EPITHELIAL CELLS FROM HIV-POSITIVE (ON HAART) AND HIV-NEGATIVE SUBJECTS. HIV-INFECTED SUBJECTS ON HIGHLY ACTIVE ANTIRETROVIRAL THERAPY (HAART) ARE SUSCEPTIBLE TO COMORBID MICROBIAL INFECTIONS IN THE ORAL CAVITY. WE OBSERVED THAT PRIMARY ORAL EPITHELIAL CELLS (POECS) ISOLATED FROM HIV+ SUBJECTS ON HAART GROW MORE SLOWLY AND ARE LESS INNATE IMMUNE RESPONSIVE TO MICROBIAL CHALLENGE WHEN COMPARED WITH POECS FROM NORMAL SUBJECTS. THESE ABERRANT CELLS ALSO DEMONSTRATE EPIGENETIC DIFFERENCES THAT INCLUDE REDUCTION IN HISTONE DEACETYLASE 1 (HDAC-1) LEVELS AND REDUCED TOTAL DNA METHYLTRANSFERASE (DNMT) ACTIVITY SPECIFIC TO ENZYMES DNMT1 AND DNMT3A. THE DNMT ACTIVITY CORRELATES WELL WITH GLOBAL DNA METHYLATION, INDICATING THAT ABERRANT DNMT ACTIVITY IN HIV+ (ON HAART) POECS LEADS TO AN ABERRANTLY METHYLATED EPITHELIAL CELL PHENOTYPE. OVERALL, OUR RESULTS LEAD US TO HYPOTHESIZE THAT, IN PATIENTS WITH CHRONIC HIV INFECTION ON HAART, EPIGENETIC CHANGES IN KEY GENES RESULT IN INCREASED VULNERABILITY TO MICROBIAL INFECTION IN THE ORAL CAVITY. 2013 6 4866 30 ORTHOGONAL CRISPR SCREENS TO IDENTIFY TRANSCRIPTIONAL AND EPIGENETIC REGULATORS OF HUMAN CD8 T CELL FUNCTION. THE CLINICAL RESPONSE TO ADOPTIVE T CELL THERAPIES IS STRONGLY ASSOCIATED WITH TRANSCRIPTIONAL AND EPIGENETIC STATE. THUS, TECHNOLOGIES TO DISCOVER REGULATORS OF T CELL GENE NETWORKS AND THEIR CORRESPONDING PHENOTYPES HAVE GREAT POTENTIAL TO IMPROVE THE EFFICACY OF T CELL THERAPIES. WE DEVELOPED POOLED CRISPR SCREENING APPROACHES WITH COMPACT EPIGENOME EDITORS TO SYSTEMATICALLY PROFILE THE EFFECTS OF ACTIVATION AND REPRESSION OF 120 TRANSCRIPTION FACTORS AND EPIGENETIC MODIFIERS ON HUMAN CD8+ T CELL STATE. THESE SCREENS NOMINATED KNOWN AND NOVEL REGULATORS OF T CELL PHENOTYPES WITH BATF3 EMERGING AS A HIGH CONFIDENCE GENE IN BOTH SCREENS. WE FOUND THAT BATF3 OVEREXPRESSION PROMOTED SPECIFIC FEATURES OF MEMORY T CELLS SUCH AS INCREASED IL7R EXPRESSION AND GLYCOLYTIC CAPACITY, WHILE ATTENUATING GENE PROGRAMS ASSOCIATED WITH CYTOTOXICITY, REGULATORY T CELL FUNCTION, AND T CELL EXHAUSTION. IN THE CONTEXT OF CHRONIC ANTIGEN STIMULATION, BATF3 OVEREXPRESSION COUNTERED PHENOTYPIC AND EPIGENETIC SIGNATURES OF T CELL EXHAUSTION. CAR T CELLS OVEREXPRESSING BATF3 SIGNIFICANTLY OUTPERFORMED CONTROL CAR T CELLS IN BOTH IN VITRO AND IN VIVO TUMOR MODELS. MOREOVER, WE FOUND THAT BATF3 PROGRAMMED A TRANSCRIPTIONAL PROFILE THAT CORRELATED WITH POSITIVE CLINICAL RESPONSE TO ADOPTIVE T CELL THERAPY. FINALLY, WE PERFORMED CRISPR KNOCKOUT SCREENS WITH AND WITHOUT BATF3 OVEREXPRESSION TO DEFINE CO-FACTORS AND DOWNSTREAM FACTORS OF BATF3, AS WELL AS OTHER THERAPEUTIC TARGETS. THESE SCREENS POINTED TO A MODEL WHERE BATF3 INTERACTS WITH JUNB AND IRF4 TO REGULATE GENE EXPRESSION AND ILLUMINATED SEVERAL OTHER NOVEL TARGETS FOR FURTHER INVESTIGATION. 2023 7 546 25 ATTENUATED EXPRESSION OF SLCO2A1 CAUSED BY DNA METHYLATION IN PEDIATRIC INFLAMMATORY BOWEL DISEASE. BACKGROUND: SLCO2A1 ENCODES A PROSTAGLANDIN (PG) TRANSPORTER, AND AUTOSOMAL RECESSIVE PATHOGENIC VARIANTS OF THIS GENE CAUSE CHRONIC ENTEROPATHY ASSOCIATED WITH SLCO2A1. IT IS UNCLEAR WHETHER A HETEROZYGOUS PATHOGENIC VARIANT OF SLCO2A1 HAS A ROLE IN THE PATHOGENESIS OF OTHER TYPES OF INFLAMMATORY BOWEL DISEASE (IBD). IN THIS STUDY, WE INVESTIGATED THE POSSIBLE INVOLVEMENT OF A LOCAL EPIGENETIC ALTERATION IN SLCO2A1 IN PATIENTS WITH A HETEROZYGOUS PATHOGENIC VARIANT. METHODS: WE CONDUCTED WHOLE-EXOME SEQUENCING OF SAMPLES FROM 2 SISTERS WITH SUSPECTED MONOGENIC IBD. IN ADDITION, WE PERFORMED BISULFITE SEQUENCING USING DNA EXTRACTED FROM THEIR SMALL AND LARGE INTESTINE SAMPLES TO EXPLORE EPIGENETIC ALTERATIONS. RESULTS: A HETEROZYGOUS SPLICING SITE VARIANT, SLCO2A1:C.940 + 1G > A, WAS DETECTED IN BOTH PATIENTS. TO EXPLORE THE POSSIBLE INVOLVEMENT OF EPIGENETIC ALTERATIONS, WE ANALYZED PROTEIN AND MESSENGER RNA EXPRESSION OF SLCO2A1, AND OBSERVED ATTENUATED SLCO2A1 EXPRESSION IN THE INFLAMED LESIONS OF THESE PATIENTS COMPARED WITH THAT IN THE CONTROL INDIVIDUALS. FURTHERMORE, BISULFITE SEQUENCING INDICATED DENSE METHYLATION IN THE PROMOTER REGION OF SLCO2A1 ONLY IN THE INFLAMED LESIONS OF BOTH PATIENTS. THE URINARY PG METABOLITE LEVELS IN THESE PATIENTS WERE COMPARABLE TO THOSE IN PATIENTS WITH CHRONIC ENTEROPATHY ASSOCIATED WITH SLCO2A1 AND HIGHER THAN THOSE IN THE CONTROL INDIVIDUALS. WE FOUND CONSIDERABLY HIGHER LEVELS OF THE METABOLITES IN PATIENT 1, WHO SHOWED MORE SEVERE SYMPTOMS THAN PATIENT 2. CONCLUSIONS: LOCAL DNA METHYLATION ATTENUATED SLCO2A1 EXPRESSION, WHICH MAY EVOKE LOCAL INFLAMMATION OF THE MUCOSA BY THE UNINCORPORATED PG. THESE FINDINGS MAY IMPROVE OUR UNDERSTANDING OF THE EPIGENETIC MECHANISMS UNDERLYING IBD DEVELOPMENT. 2023 8 272 33 AGE-DEPENDENT DECREASE IN THE INDUCTION OF REGULATORY T CELLS IS ASSOCIATED WITH DECREASED EXPRESSION OF RALDH2 IN MESENTERIC LYMPH NODE DENDRITIC CELLS. A DECLINE IN IMMUNE FUNCTION WITH AGING HAS BEEN REPORTED. REGULATORY T CELL (TREG) INDUCTION IS KNOWN TO DECREASE WITH AGE, AND ELUCIDATING THE UNDERLYING MECHANISM IS IMPORTANT FOR PREVENTING AGE-RELATED DISEASES DUE TO AGE-RELATED CHRONIC INFLAMMATION. IN THE INTESTINE, DENDRITIC CELLS (DCS) PLAY AN IMPORTANT ROLE IN INDUCING TREGS SPECIFIC TO ORAL ANTIGENS, AND THEY EFFICIENTLY INDUCE TREGS VIA PRODUCTION OF RETINOIC ACID (RA), A VITAMIN A METABOLITE, CATALYZED BY THE ENZYME RETINALDEHYDE DEHYDROGENASE 2 (RALDH2). WE HAVE PREVIOUSLY REPORTED THAT IN THE MESENTERIC LYMPH NODE (MLN), A SECONDARY LYMPHOID TISSUE IN WHICH IMMUNE RESPONSES TO ORAL ANTIGENS ARE INDUCED, FOUR DC SUBSETS EXPRESS DIFFERENT LEVELS OF CD11B, CD103, AND PD-L1, AND WE HAVE REPORTED THAT THE CD11B(-)CD103(+)PD-L1(HIGH) SUBSET EXPRESSES THE HIGHEST LEVELS OF THE RALDH2 GENE AND INDUCES TREGS IN VITRO. WE EXAMINED TREG INDUCTION IN YOUNG AND AGED MICE USING A TREG INDUCTION MODEL BY ADMINISTERING A FOOD ANTIGEN, AND WE FOUND THAT ANTIGEN-SPECIFIC TREG INDUCTION WAS DECREASED IN AGED MICE. WE FURTHER INVESTIGATED THE MLN DCS, AND A SIGNIFICANT DECREASE IN RALDH2 GENE EXPRESSION WAS OBSERVED IN MLN DCS FROM AGED MICE. AS FACTORS, WE FOUND THAT THE PROPORTION OF THE CD11B(-)CD103(+)PD-L1(HIGH) SUBSET WAS DECREASED IN AGED MICE COMPARED WITH THAT IN YOUNG MICE AND THAT RALDH ENZYME ACTIVITY WAS DECREASED IN THE CD11B(-)CD103(+)PD-L1(HIGH) AND CD11B(+)CD103(+)PD-L1(HIGH) SUBSETS. FURTHERMORE, ANALYSIS OF THE METHYLATION OF THE RALDH2 GENE PROMOTER REGION REVEALED THAT CPG MOTIFS WERE MORE METHYLATED IN THE MLN DCS OF AGED MICE, SUGGESTING THAT RALDH2 EXPRESSION WAS SUPPRESSED BY EPIGENETIC CHANGES. FINALLY, WE FOUND THAT RA TREATMENT TENDED TO INCREASE TREG INDUCTION. THESE RESULTS SUGGEST THAT THE REGULATION OF RA PRODUCTION MAY BE INVOLVED IN THE AGE-RELATED DECREASE IN ANTIGEN-SPECIFIC TREG INDUCTION. 2020 9 6826 27 [GENOME-WIDE ANALYSIS OF DNA METHYLATION IN CD4+ T LYMPHOCYTES OF PATIENTS WITH PRIMARY PROGRESSIVE MULTIPLE SCLEROSIS INDICATES INVOLVEMENT OF THIS EPIGENETIC PROCESS IN THE DISEASE IMMUNOPATHOGENESIS]. THE PATHOGENESIS OF MULTIPLE SCLEROSIS (MS), A CHRONIC DISEASE OF THE CNS, INCLUDES AUTOIMMUNE AND NEURODEGENERATIVE COMPONENTS. IN MOST CASES, PATIENTS DEVELOP RELAPSING-REMITTING MS (RRMS), WHILE 10-15% OF PATIENTS DEVELOP PRIMARY PROGRESSIVE MS (PPMS), WHICH DIFFERS FROM RRMS IN THE MECHANISMS OF THE PATHOLOGICAL PROCESS, SOME DEMOGRAPHIC, AND SOME CLINICAL CHARACTERISTICS. THESE DIFFERENCES MAY BE EXPLAINED BY THE EPIGENETIC REGULATION OF GENE EXPRESSION IN PPMS INCLUDING DNA METHYLATION AS ONE OF THE KEY EPIGENETIC PROCESSES. THE FEATURES OF DNA METHYLATION IN VARIOUS CELL POPULATIONS IN PPMS PATIENTS REMAIN UNDERSTUDIED. THE GOAL OF THIS STUDY IS TO IDENTIFY DIFFERENTIALLY METHYLATED CPG SITES (DMSS) OF THE GENOME OF CD4+ T LYMPHOCYTES, WHICH CHARACTERIZE PPMS. THE STUDY INCLUDED EIGHT TREATMENT-NAIVE PPMS PATIENTS AND EIGHT HEALTHY CONTROLS. GENOME-WIDE ANALYSIS OF DNA METHYLATION OF CD4+ T LYMPHOCYTES WAS PERFORMED USING HIGH-DENSITY DNA MICROARRAYS. WE HAVE IDENTIFIED 108 DMSS, WHICH DISTINGUISH PPMS PATIENTS FROM HEALTHY CONTROLS. IN PPMS PATIENTS 81% OF THE DMSS ARE HYPERMETHYLATED. MORE THAN A HALF OF THE IDENTIFIED DMSS ARE LOCATED IN KNOWN GENES IN CPG ISLANDS AND ADJACENT REGIONS, WHICH INDICATES A HIGH FUNCTIONAL SIGNIFICANCE OF THESE DMSS IN PPMS DEVELOPMENT. ANALYSIS OF THE OVERREPRESENTATION OF DMS-CONTAINING GENES IN THE MAIN BIOLOGICAL PROCESSES DEMONSTRATES THEIR INVOLVEMENT IN THE REGULATION OF CELL ADHESION TO THE EXTRACELLULAR MATRIX AND THE DEVELOPMENT OF THE IMMUNE RESPONSE, I.E., ANTIGEN PROCESSING AND PRESENTATION, AND DEVELOPMENT OF THE IMMUNE SYSTEM. GENOME-WIDE ANALYSIS OF DNA METHYLATION IN CD4+ T LYMPHOCYTES OF PPMS PATIENTS INDICATES THE INVOLVEMENT OF THIS EPIGENETIC PROCESS IN THE IMMUNOPATHOGENESIS OF THE DISEASE. THESE RESULTS MAY HELP BETTER UNDERSTAND THE PATHOGENESIS OF THIS SEVERE FORM OF MS. 2022 10 466 36 ARE THE HEALTHY VULNERABLE? CYTOMEGALOVIRUS SEROPOSITIVITY IN HEALTHY ADULTS IS ASSOCIATED WITH ACCELERATED EPIGENETIC AGE AND IMMUNE DYSREGULATION. BACKGROUND: EVALUATING AGE AS A RISK FACTOR FOR SUSCEPTIBILITY TO INFECTIOUS DISEASES, PARTICULARLY CORONAVIRUS DISEASE 2019 (COVID-19), IS CRITICAL. CYTOMEGALOVIRUS (CMV) SEROLOGIC PREVALENCE INCREASES WITH AGE AND ASSOCIATES WITH INFLAMMATORY-MEDIATED DISEASES IN THE ELDERLY. HOWEVER, LITTLE IS KNOWN REGARDING THE SUBCLINICAL IMPACT OF CMV AND RISK IT POSES TO HEALTHY OLDER ADULTS. PRIOR TO THE COVID-19 PANDEMIC WE CONDUCTED A STUDY TO DETERMINE THE ASSOCIATION OF CMV TO BIOLOGIC AGE AND IMMUNE DYSREGULATION. METHODS: COMMUNITY-DWELLING, HEALTHY ADULTS OLDER THAN 60 YEARS WERE EVALUATED USING DNA METHYLATION ASSAYS TO DEFINE EPIGENETIC AGE (EPIAGE) AND T-CELL IMMUNOPHENOTYPING TO ASSESS IMMUNE DYSREGULATION. RESULTS: ALL SUBJECTS WERE HEALTHY AND ASYMPTOMATIC. THOSE CMV SEROPOSITIVE HAD MORE LYMPHOCYTES, CD8 T CELLS, CD28- T CELLS, DECREASED CD4:CD8 CELL RATIOS, AND HAD HIGHER AVERAGE EPIAGE (65.34 YEARS) THAN THOSE CMV SERONEGATIVE (59.53 YEARS). DECREASED PERCENT CD4 (P = .003) AND NUMBERS OF CD4 T CELLS (P = .0199) CORRELATED WITH INCREASED EPIAGE. CONCLUSIONS: OUR NOVEL FINDINGS DISTINGUISH ALTERED IMMUNITY IN THE ELDERLY BASED ON CMV STATUS. CHRONIC CMV INFECTION IN HEALTHY, OLDER ADULTS IS ASSOCIATED WITH INDICATORS OF IMMUNE DYSREGULATION, BOTH OF WHICH CORRELATE TO DIFFERENCES IN EPIAGE. 2022 11 275 26 AGE-RELATED CLONAL HAEMOPOIESIS IS ASSOCIATED WITH INCREASED EPIGENETIC AGE. AGE-RELATED CLONAL HAEMOPOIESIS (ARCH) IN HEALTHY INDIVIDUALS WAS INITIALLY OBSERVED THROUGH AN INCREASED SKEWING IN X-CHROMOSOME INACTIVATION [1]. MORE RECENTLY, SEVERAL GROUPS REPORTED THAT ARCH IS DRIVEN BY SOMATIC MUTATIONS [2], WITH THE MOST PREVALENT ARCH MUTATIONS BEING IN THE DNMT3A AND TET2 GENES, PREVIOUSLY DESCRIBED AS DRIVERS OF MYELOID MALIGNANCIES. ARCH IS ASSOCIATED WITH AN INCREASED RISK FOR HAEMATOLOGICAL CANCERS [2]. ARCH ALSO CONFERS AN INCREASED RISK FOR NON-HAEMATOLOGICAL DISEASES, SUCH AS CARDIOVASCULAR DISEASE, ATHEROSCLEROSIS, AND CHRONIC ISCHEMIC HEART FAILURE, FOR WHICH AGE IS A MAIN RISK FACTOR [3,4]. WHETHER ARCH IS LINKED TO ACCELERATED AGEING HAS REMAINED UNEXPLORED. THE MOST ACCURATE AND COMMONLY USED TOOLS TO MEASURE AGE ACCELERATION ARE EPIGENETIC CLOCKS: THEY ARE BASED ON AGE-RELATED METHYLATION DIFFERENCES AT SPECIFIC CPG SITES [5]. DEVIATIONS FROM CHRONOLOGICAL AGE TOWARDS AN INCREASED EPIGENETIC AGE HAVE BEEN ASSOCIATED WITH INCREASED RISK OF EARLIER MORTALITY AND AGE-RELATED MORBIDITIES [5,6]. HERE WE PRESENT EVIDENCE OF ACCELERATED EPIGENETIC AGE IN INDIVIDUALS WITH ARCH. 2019 12 5153 18 PPP2R2B HYPERMETHYLATION CAUSES ACQUIRED APOPTOSIS DEFICIENCY IN SYSTEMIC AUTOIMMUNE DISEASES. CHRONIC INFLAMMATION CAUSES TARGET ORGAN DAMAGE IN PATIENTS WITH SYSTEMIC AUTOIMMUNE DISEASES. THE FACTORS THAT ALLOW THIS PROTRACTED RESPONSE ARE POORLY UNDERSTOOD. WE ANALYZED THE TRANSCRIPTIONAL REGULATION OF PPP2R2B (B55SS), A MOLECULE NECESSARY FOR THE TERMINATION OF THE IMMUNE RESPONSE, IN PATIENTS WITH AUTOIMMUNE DISEASES. ALTERED EXPRESSION OF B55SS CONDITIONED RESISTANCE TO CYTOKINE WITHDRAWAL-INDUCED DEATH (CWID) IN PATIENTS WITH AUTOIMMUNE DISEASES. THE IMPAIRED UPREGULATION OF B55SS WAS CAUSED BY INFLAMMATION-DRIVEN HYPERMETHYLATION OF SPECIFIC CYTOSINES LOCATED WITHIN A REGULATORY ELEMENT OF PPP2R2B PREVENTING CTCF BINDING. THIS PHENOTYPE COULD BE INDUCED IN HEALTHY T CELLS BY EXPOSURE TO TNF-ALPHA. OUR RESULTS REVEAL A GENE WHOSE EXPRESSION IS AFFECTED BY AN ACQUIRED DEFECT, THROUGH AN EPIGENETIC MECHANISM, IN THE SETTING OF SYSTEMIC AUTOIMMUNITY. BECAUSE FAILURE TO REMOVE ACTIVATED T CELLS THROUGH CWID COULD CONTRIBUTE TO AUTOIMMUNE PATHOLOGY, THIS MECHANISM ILLUSTRATES A VICIOUS CYCLE THROUGH WHICH AUTOIMMUNE INFLAMMATION CONTRIBUTES TO ITS OWN PERPETUATION. 2019 13 3764 29 INTEGRATIVE ANALYSIS OF DNA METHYLATION AND GENE EXPRESSION DATA IDENTIFIES EPAS1 AS A KEY REGULATOR OF COPD. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS A COMPLEX DISEASE. GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS ARE KNOWN TO CONTRIBUTE TO COPD RISK AND DISEASE PROGRESSION. THEREFORE WE DEVELOPED A SYSTEMATIC APPROACH TO IDENTIFY KEY REGULATORS OF COPD THAT INTEGRATES GENOME-WIDE DNA METHYLATION, GENE EXPRESSION, AND PHENOTYPE DATA IN LUNG TISSUE FROM COPD AND CONTROL SAMPLES. OUR INTEGRATIVE ANALYSIS IDENTIFIED 126 KEY REGULATORS OF COPD. WE IDENTIFIED EPAS1 AS THE ONLY KEY REGULATOR WHOSE DOWNSTREAM GENES SIGNIFICANTLY OVERLAPPED WITH MULTIPLE GENES SETS ASSOCIATED WITH COPD DISEASE SEVERITY. EPAS1 IS DISTINCT IN COMPARISON WITH OTHER KEY REGULATORS IN TERMS OF METHYLATION PROFILE AND DOWNSTREAM TARGET GENES. GENES PREDICTED TO BE REGULATED BY EPAS1 WERE ENRICHED FOR BIOLOGICAL PROCESSES INCLUDING SIGNALING, CELL COMMUNICATIONS, AND SYSTEM DEVELOPMENT. WE CONFIRMED THAT EPAS1 PROTEIN LEVELS ARE LOWER IN HUMAN COPD LUNG TISSUE COMPARED TO NON-DISEASE CONTROLS AND THAT EPAS1 GENE EXPRESSION IS REDUCED IN MICE CHRONICALLY EXPOSED TO CIGARETTE SMOKE. AS EPAS1 DOWNSTREAM GENES WERE SIGNIFICANTLY ENRICHED FOR HYPOXIA RESPONSIVE GENES IN ENDOTHELIAL CELLS, WE TESTED EPAS1 FUNCTION IN HUMAN ENDOTHELIAL CELLS. EPAS1 KNOCKDOWN BY SIRNA IN ENDOTHELIAL CELLS IMPACTED GENES THAT SIGNIFICANTLY OVERLAPPED WITH EPAS1 DOWNSTREAM GENES IN LUNG TISSUE INCLUDING HYPOXIA RESPONSIVE GENES, AND GENES ASSOCIATED WITH EMPHYSEMA SEVERITY. OUR FIRST INTEGRATIVE ANALYSIS OF GENOME-WIDE DNA METHYLATION AND GENE EXPRESSION PROFILES ILLUSTRATES THAT NOT ONLY DOES DNA METHYLATION PLAY A 'CAUSAL' ROLE IN THE MOLECULAR PATHOPHYSIOLOGY OF COPD, BUT IT CAN BE LEVERAGED TO DIRECTLY IDENTIFY NOVEL KEY MEDIATORS OF THIS PATHOPHYSIOLOGY. 2015 14 662 23 BLOOD MONOCYTE TRANSCRIPTOME AND EPIGENOME ANALYSES REVEAL LOCI ASSOCIATED WITH HUMAN ATHEROSCLEROSIS. LITTLE IS KNOWN REGARDING THE EPIGENETIC BASIS OF ATHEROSCLEROSIS. HERE WE PRESENT THE CD14+ BLOOD MONOCYTE TRANSCRIPTOME AND EPIGENOME SIGNATURES ASSOCIATED WITH HUMAN ATHEROSCLEROSIS. THE TRANSCRIPTOME SIGNATURE INCLUDES TRANSCRIPTION COACTIVATOR, ARID5B, WHICH IS KNOWN TO FORM A CHROMATIN DEREPRESSOR COMPLEX WITH A HISTONE H3K9ME2-SPECIFIC DEMETHYLASE AND PROMOTE ADIPOGENESIS AND SMOOTH MUSCLE DEVELOPMENT. ARID5B CPG (CG25953130) METHYLATION IS INVERSELY ASSOCIATED WITH BOTH ARID5B EXPRESSION AND ATHEROSCLEROSIS, CONSISTENT WITH THIS CPG RESIDING IN AN ARID5B ENHANCER REGION, BASED ON CHROMATIN CAPTURE AND HISTONE MARKS DATA. MEDIATION ANALYSIS SUPPORTS ASSUMPTIONS THAT ARID5B EXPRESSION MEDIATES EFFECTS OF CG25953130 METHYLATION AND SEVERAL CARDIOVASCULAR DISEASE RISK FACTORS ON ATHEROSCLEROTIC BURDEN. IN LIPOPOLYSACCHARIDE-STIMULATED HUMAN THP1 MONOCYTES, ARID5B KNOCKDOWN REDUCED EXPRESSION OF GENES INVOLVED IN ATHEROSCLEROSIS-RELATED INFLAMMATORY AND LIPID METABOLISM PATHWAYS, AND INHIBITED CELL MIGRATION AND PHAGOCYTOSIS. THESE DATA SUGGEST THAT ARID5B EXPRESSION, POSSIBLY REGULATED BY AN EPIGENETICALLY CONTROLLED ENHANCER, PROMOTES ATHEROSCLEROSIS BY DYSREGULATING IMMUNOMETABOLISM TOWARDS A CHRONIC INFLAMMATORY PHENOTYPE.THE MOLECULAR MECHANISMS MEDIATING THE IMPACT OF ENVIRONMENTAL FACTORS IN ATHEROSCLEROSIS ARE UNCLEAR. HERE, THE AUTHORS EXAMINE CD14+ BLOOD MONOCYTE'S TRANSCRIPTOME AND EPIGENOME SIGNATURES TO FIND DIFFERENTIAL METHYLATION AND EXPRESSION OF ARID5B TO BE ASSOCIATED WITH HUMAN ATHEROSCLEROSIS. 2017 15 5464 21 RESILIENCE IN LONG-TERM VIRAL INFECTION: GENETIC DETERMINANTS AND INTERACTIONS. VIRUS-INDUCED NEUROLOGICAL SEQUELAE RESULTING FROM INFECTION BY THEILER'S MURINE ENCEPHALOMYELITIS VIRUS (TMEV) ARE USED FOR STUDYING HUMAN CONDITIONS RANGING FROM EPILEPTIC SEIZURES TO DEMYELINATING DISEASE. MOUSE STRAINS ARE TYPICALLY CONSIDERED SUSCEPTIBLE OR RESISTANT TO TMEV INFECTION BASED ON VIRAL PERSISTENCE AND EXTREME PHENOTYPES, SUCH AS DEMYELINATION. WE HAVE IDENTIFIED A BROADER SPECTRUM OF PHENOTYPIC OUTCOMES BY INFECTING STRAINS OF THE GENETICALLY DIVERSE COLLABORATIVE CROSS (CC) MOUSE RESOURCE. WE EVALUATED THE CHRONIC-INFECTION GENE EXPRESSION PROFILES OF HIPPOCAMPI AND THORACIC SPINAL CORDS FOR 19 CC STRAINS IN RELATION TO PHENOTYPIC SEVERITY AND TMEV PERSISTENCE. STRAINS WERE CLUSTERED BASED ON SIMILAR PHENOTYPIC PROFILES AND TMEV LEVELS AT 90 DAYS POST-INFECTION, AND WE CATEGORIZED DISTINCT TMEV RESPONSE PROFILES. THE THREE MOST COMMON PROFILES INCLUDED "RESISTANT" AND "SUSCEPTIBLE," AS BEFORE, AS WELL AS A "RESILIENT" TMEV RESPONSE GROUP WHICH EXPERIENCED BOTH TMEV PERSISTENCE AND MILD NEUROLOGICAL PHENOTYPES EVEN AT 90 DAYS POST-INFECTION. EACH PROFILE HAD A DISTINCT GENE EXPRESSION SIGNATURE, ALLOWING THE IDENTIFICATION OF PATHWAYS AND NETWORKS SPECIFIC TO EACH TMEV RESPONSE GROUP. CC FOUNDER HAPLOTYPES FOR GENES INVOLVED IN THESE PATHWAYS/NETWORKS REVEALED CANDIDATE RESPONSE-SPECIFIC ALLELES. THESE ALLELES DEMONSTRATED PLEIOTROPY AND EPIGENETIC (MIRNA) REGULATION IN LONG-TERM TMEV INFECTION, WITH PARTICULAR RELEVANCE FOR RESILIENT MOUSE STRAINS. 2021 16 3296 30 HIGH RESOLUTION INTEGRATIVE ANALYSIS REVEALS WIDESPREAD GENETIC AND EPIGENETIC CHANGES AFTER CHRONIC IN-VITRO ACID AND BILE EXPOSURE IN BARRETT'S EPITHELIUM CELLS. BARRETT'S EPITHELIUM (BE) IS A PREMALIGNANT CONDITION RESULTING FROM CHRONIC GASTROESOPHAGEAL REFLUX THAT MAY PROGRESS TO ESOPHAGEAL ADENOCARCINOMA (EAC). EARLY INTERVENTION HOLDS PROMISE IN PREVENTING BE PROGRESSION. HOWEVER, IDENTIFICATION OF HIGH-RISK BE PATIENTS REMAINS CHALLENGING DUE TO INADEQUATE BIOMARKERS FOR EARLY DIAGNOSIS. WE INVESTIGATED THE EFFECT OF PROLONGED CHRONIC ACID AND BILE EXPOSURE ON TRANSCRIPTOME, METHYLOME, AND MUTATOME OF CELLS IN AN IN-VITRO BE CARCINOGENESIS (BEC) MODEL. TWENTY WEEKS ACID AND BILE EXPOSED CELLS FROM THE BEC MODEL (BEC20W) WERE COMPARED WITH THEIR NAIVE PREDECESSORS HISEQ ILLUMINA BASED RNA SEQUENCING WAS PERFORMED ON RNA FROM BOTH THE CELLS FOR GENE EXPRESSION AND MUTATIONAL ANALYSIS. HELP TAGGING ASSAY WAS PERFORMED FOR DNA METHYLATION ANALYSIS. INGENUITY PATHWAY, GENE ONTOLOGY, AND KEGG PATHWAY ANALYSES WERE THEN PERFORMED ON DATASETS. WIDESPREAD ABERRANT GENETIC AND EPIGENETIC CHANGES WERE OBSERVED IN THE BEC20W CELLS. COMBINATORIAL ANALYSES REVEALED 433 FROM A TOTAL OF 863 DOWNREGULATED GENES HAD ACCOMPANYING HYPERMETHYLATION OF PROMOTERS. SIMULTANEOUSLY, 690 GENES FROM A TOTAL OF 1,492 WERE UPREGULATED WITH ACCOMPANYING PROMOTER HYPOMETHYLATION. IN ADDITION, 763 MUTATIONS WERE IDENTIFIED ON 637 GENES. INGENUITY PATHWAY ANALYSIS, GENE ONTOLOGY, AND KEGG PATHWAY ANALYSES ASSOCIATED THE GENETIC AND EPIGENETIC CHANGES IN BEC20W CELLS WITH CELLULAR AND BIOLOGICAL FUNCTIONS. INTEGRATION OF HIGH RESOLUTION COMPARATIVE ANALYSES OF NAIVE BAR-T AND BEC20W CELLS REVEALED STRIKING GENETIC AND EPIGENETIC CHANGES INDUCED BY CHRONIC ACID AND BILE EXPOSURE THAT MAY DISRUPT NORMAL CELLULAR FUNCTIONS AND PROMOTE CARCINOGENESIS. THIS NOVEL STUDY REVEALS SEVERAL POTENTIAL TARGETS FOR FUTURE BIOMARKERS AND THERAPEUTIC DEVELOPMENT. 2013 17 1598 30 DNA METHYLATION SIGNATURE IN MONONUCLEAR CELLS AND PROINFLAMMATORY CYTOKINES MAY DEFINE MOLECULAR SUBTYPES IN SPORADIC MENIERE DISEASE. MENIERE DISEASE (MD) IS A MULTIFACTORIAL DISORDER OF THE INNER EAR CHARACTERIZED BY VERTIGO ATTACKS ASSOCIATED WITH SENSORINEURAL HEARING LOSS AND TINNITUS WITH A SIGNIFICANT HERITABILITY. ALTHOUGH MD HAS BEEN ASSOCIATED WITH SEVERAL GENES, NO EPIGENETIC STUDIES HAVE BEEN PERFORMED ON MD. HERE WE PERFORMED WHOLE-GENOME BISULFITE SEQUENCING IN 14 MD PATIENTS AND SIX HEALTHY CONTROLS, WITH THE AIM OF IDENTIFYING AN MD METHYLATION SIGNATURE AND POTENTIAL DISEASE MECHANISMS. WE OBSERVED A HIGH NUMBER OF DIFFERENTIALLY METHYLATED CPGS (DMC) WHEN COMPARING MD PATIENTS TO CONTROLS (N= 9545), SEVERAL OF THEM IN HEARING LOSS GENES, SUCH AS PCDH15, ADGRV1 AND CDH23. BIOINFORMATIC ANALYSES OF DMCS AND CIS-REGULATORY REGIONS PREDICTED PHENOTYPES RELATED TO ABNORMAL EXCITATORY POSTSYNAPTIC CURRENTS, ABNORMAL NMDA-MEDIATED RECEPTOR CURRENTS AND ABNORMAL GLUTAMATE-MEDIATED RECEPTOR CURRENTS WHEN COMPARING MD TO CONTROLS. MOREOVER, WE IDENTIFIED VARIOUS DMCS IN GENES PREVIOUSLY ASSOCIATED WITH COCHLEOVESTIBULAR PHENOTYPES IN MICE. WE HAVE ALSO FOUND 12 UNDERMETHYLATED REGIONS (UMR) THAT WERE EXCLUSIVE TO MD, INCLUDING TWO UMR IN AN INTER CPG ISLAND IN THE PHB GENE. WE SUGGEST THAT THE DNA METHYLATION SIGNATURE ALLOWS DISTINGUISHING BETWEEN MD PATIENTS AND CONTROLS. THE ENRICHMENT ANALYSIS CONFIRMS PREVIOUS FINDINGS OF A CHRONIC INFLAMMATORY PROCESS UNDERLYING MD. 2021 18 493 21 ASSESSMENT OF P53 AND ATM FUNCTIONALITY IN CHRONIC LYMPHOCYTIC LEUKEMIA BY MULTIPLEX LIGATION-DEPENDENT PROBE AMPLIFICATION. THE ATM-P53 DNA-DAMAGE RESPONSE (DDR) PATHWAY HAS A CRUCIAL ROLE IN CHEMORESISTANCE IN CLL, AS INDICATED BY THE ADVERSE PROGNOSTIC IMPACT OF GENETIC ABERRATIONS OF TP53 AND ATM. IDENTIFYING AND DISTINGUISHING TP53 AND ATM FUNCTIONAL DEFECTS HAS BECOME RELEVANT AS EPIGENETIC AND POSTTRANSCRIPTIONAL DYSREGULATION OF THE ATM/P53 AXIS IS INCREASINGLY BEING RECOGNIZED AS THE UNDERLYING CAUSE OF CHEMORESISTANCE. ALSO, SPECIFIC TREATMENTS SENSITIZING TP53- OR ATM-DEFICIENT CLL CELLS ARE EMERGING. WE THEREFORE DEVELOPED A NEW ATM-P53 FUNCTIONAL ASSAY WITH THE AIM TO (I) IDENTIFY AND (II) DISTINGUISH ABNORMALITIES OF TP53 VERSUS ATM AND (III) ENABLE THE IDENTIFICATION OF ADDITIONAL DEFECTS IN THE ATM-P53 PATHWAY. REVERSED TRANSCRIPTASE MULTIPLEX LIGATION-DEPENDENT PROBE AMPLIFICATION (RT-MLPA) WAS USED TO MEASURE ATM AND/OR P53-DEPENDENT GENES AT THE RNA LEVEL FOLLOWING DNA DAMAGE USING IRRADIATION. HERE, WE SHOWED THAT THIS ASSAY IS ABLE TO IDENTIFY AND DISTINGUISH THREE SUBGROUPS OF CLL TUMORS (I.E., TP53-DEFECTIVE, ATM-DEFECTIVE AND WT) AND IS ALSO ABLE TO DETECT ADDITIONAL SAMPLES WITH A DEFECTIVE DDR, WITHOUT MOLECULAR ABERRATIONS IN TP53 AND/OR ATM. THESE FINDINGS MAKE THE ATM-P53 RT-MLPA FUNCTIONAL ASSAY A PROMISING PROGNOSTIC TOOL FOR PREDICTING TREATMENT RESPONSES IN CLL. 2015 19 3125 22 GHSR DNA HYPERMETHYLATION IS A COMMON EPIGENETIC ALTERATION OF HIGH DIAGNOSTIC VALUE IN A BROAD SPECTRUM OF CANCERS. IDENTIFICATION OF A SINGLE MOLECULAR TRAIT THAT IS DETERMINANT OF COMMON MALIGNANCIES MAY SERVE AS A POWERFUL DIAGNOSTIC SUPPLEMENT TO CANCER TYPE-SPECIFIC MARKERS. HERE, WE REPORT A DNA METHYLATION MARK THAT IS CHARACTERISTIC OF SEVEN STUDIED MALIGNANCIES, NAMELY CANCERS OF LUNG, BREAST, PROSTATE, PANCREAS, COLORECTUM, GLIOBLASTOMA AND B CELL CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) (N = 137). THIS MARK WAS DEFINED BY SUBSTANTIAL HYPERMETHYLATION AT THE PROMOTER AND FIRST EXON OF GROWTH HORMONE SECRETAGOUGE RECEPTOR (GHSR) THROUGH BISULFITE PYROSEQUENCING. THE DEGREE OF ABERRANT METHYLATION WAS CAPABLE OF ACCURATE DISCRIMINATION BETWEEN CANCER AND CONTROL SAMPLES. THE HIGHEST SENSITIVITY AND SPECIFICITY OF CANCER DETECTION WAS ACHIEVED FOR CANCERS OF PANCREAS, LUNG, BREAST AND CLL YIELDING THE AREA UNDER THE CURVE (AUC) VALUES OF 1.0000, 0.9952, 0.9800 AND 0.9400, RESPECTIVELY. NARROWING TO A SINGLE CPG SITE WITHIN THE GENE'S PROMOTER OR FOUR CONSECUTIVE CPG UNITS OF THE HIGHEST METHYLATION LEVELS WITHIN THE FIRST EXON IMPROVED THE DETECTION POWER. GHSR HYPERMETHYLATION WAS DETECTED ALREADY AT THE EARLY STAGE TUMORS. THE ACCURATE PERFORMANCE OF THIS MARKER WAS FURTHER REPLICATED IN AN INDEPENDENT SET OF PANCREATIC CANCER AND CONTROL SAMPLES (N = 78). THESE FINDINGS SUPPORT THE CANDIDATURE OF GHSR METHYLATION AS A HIGHLY ACCURATE PAN-CANCER MARKER. 2015 20 2664 37 ESTABLISHMENT AND VALIDATION OF EXHAUSTED CD8+ T CELL FEATURE AS A PROGNOSTIC MODEL OF HCC. OBJECTIVES: THE EXHAUSTED CD8+T (TEX) CELLS ARE A UNIQUE CELL POPULATION OF ACTIVATED T CELLS THAT EMERGES IN RESPONSE TO PERSISTENT VIRAL INFECTION OR TUMOR ANTIGENS. TEX CELLS SHOWED THE CHARACTERISTICS OF AGING CELLS, INCLUDING WEAKENED SELF-RENEWAL ABILITY, EFFECTOR FUNCTION INHIBITION, SUSTAINED HIGH EXPRESSION OF INHIBITORY RECEPTORS INCLUDING PD-1, TIGIT, TIM-3, AND LAG-3, AND ALWAYS ACCOMPANIED BY METABOLIC AND EPIGENETIC REPROGRAMMING. TEX CELLS ARE GETTING MORE AND MORE ATTENTION IN RESEARCHING IMMUNE-RELATED DISEASES AND TUMOR IMMUNOTHERAPY. HOWEVER, STUDIES ON TEX-RELATED MODELS FOR TUMOR PROGNOSIS ARE STILL LACKING. WE HOPE TO ESTABLISH A RISK MODEL BASED ON TEX-RELATED GENES FOR HCC PROGNOSIS. METHODS: TEX-RELATED GEO DATASETS FROM DIFFERENT PATHOLOGIC FACTORS (CHRONIC HBV, CHRONIC HCV, AND TELOMERE SHORTENING) WERE ANALYZED RESPECTIVELY TO ACQUIRE DIFFERENTIALLY EXPRESSED GENES (DEGS) BY THE 'LIMMA' PACKAGE OF R. GENES WITH AT LEAST ONE INTERSECTION WERE INCORPORATED INTO TEX-RELATED GENE SET. GO, KEGG, AND GSEA ENRICHMENT ANALYSES WERE PRODUCED. HUB GENES AND THE PPI NETWORK WERE ESTABLISHED AND VISUALIZED BY THE STRING WEBSITE AND CYTOSCAPE SOFTWARE. TRANSCRIPTION FACTORS AND TARGETING SMALL MOLECULES WERE PREDICTED BY THE TRUST AND CLUE WEBSITES. THE TEX-RELATED HCC PROGNOSTIC MODEL WAS BUILT BY COX REGRESSION AND VERIFIED BASED ON DIFFERENT DATASETS. TUMOR IMMUNE DYSFUNCTION AND EXCLUSION (TIDE) AND SUBMAP ALGORITHMS TESTED IMMUNOTHERAPY SENSITIVITY. FINALLY, QRT-PCR AND FLOW CYTOMETRY WAS USED TO CONFIRM THE BIOINFORMATIC RESULTS. RESULTS: HUB GENES SUCH AS AKT1, CDC6, TNF AND THEIR UPSTREAM TRANSCRIPTION FACTOR ILF3, REGULATORY FACTOR X-ASSOCIATED PROTEIN, STAT3, JUN, AND RELA/NFKB1 WERE IDENTIFIED AS POTENTIAL MOTIVATORS FOR TEX. TEX-RELATED GENES SLC16A11, CACYBP, HSF2, AND ATG10 BUILT THE HCC PROGNOSTIC MODEL AND HELPED WITH IMMUNOTHERAPY SENSITIVITY PREDICTION. CONCLUSION: OUR STUDY DEMONSTRATED THAT TEX-RELATED GENES MIGHT PROVIDE ACCURATE PREDICTION FOR HCC PATIENTS IN CLINICAL DECISION-MAKING, PROGNOSTIC ASSESSMENT, AND IMMUNOTHERAPY. IN ADDITION, TARGETING THE HUB GENES OR TRANSCRIPTION FACTORS MAY HELP TO REVERSE T CELL FUNCTION AND ENHANCE THE EFFECT OF TUMOR IMMUNOTHERAPY. 2023