1 6568 158 TRANSMATERNAL HELICOBACTER PYLORI EXPOSURE REDUCES ALLERGIC AIRWAY INFLAMMATION IN OFFSPRING THROUGH REGULATORY T CELLS. BACKGROUND: TRANSMATERNAL EXPOSURE TO TOBACCO, MICROBES, NUTRIENTS, AND OTHER ENVIRONMENTAL FACTORS SHAPES THE FETAL IMMUNE SYSTEM THROUGH EPIGENETIC PROCESSES. THE GASTRIC MICROBE HELICOBACTER PYLORI REPRESENTS AN ANCESTRAL CONSTITUENT OF THE HUMAN MICROBIOTA THAT CAUSES GASTRIC DISORDERS ON THE ONE HAND AND IS INVERSELY ASSOCIATED WITH ALLERGIES AND CHRONIC INFLAMMATORY CONDITIONS ON THE OTHER. OBJECTIVE: HERE WE INVESTIGATE THE CONSEQUENCES OF TRANSMATERNAL EXPOSURE TO H PYLORI IN UTERO AND/OR DURING LACTATION FOR SUSCEPTIBILITY TO VIRAL AND BACTERIAL INFECTION, PREDISPOSITION TO ALLERGIC AIRWAY INFLAMMATION, AND DEVELOPMENT OF IMMUNE CELL POPULATIONS IN THE LUNGS AND LYMPHOID ORGANS. METHODS: WE USE EXPERIMENTAL MODELS OF HOUSE DUST MITE- OR OVALBUMIN-INDUCED AIRWAY INFLAMMATION AND INFLUENZA A VIRUS OR CITROBACTER RODENTIUM INFECTION ALONG WITH METAGENOMICS ANALYSES, MULTICOLOR FLOW CYTOMETRY, AND BISULFITE PYROSEQUENCING, TO STUDY THE EFFECTS OF H PYLORI ON ALLERGY SEVERITY AND IMMUNOLOGIC AND MICROBIOME CORRELATES THEREOF. RESULTS: PERINATAL EXPOSURE TO H PYLORI EXTRACT OR ITS IMMUNOMODULATOR VACUOLATING CYTOTOXIN CONFERS ROBUST PROTECTIVE EFFECTS AGAINST ALLERGIC AIRWAY INFLAMMATION NOT ONLY IN FIRST- BUT ALSO SECOND-GENERATION OFFSPRING BUT DOES NOT INCREASE SUSCEPTIBILITY TO VIRAL OR BACTERIAL INFECTION. IMMUNE CORRELATES OF ALLERGY PROTECTION INCLUDE SKEWING OF REGULATORY OVER EFFECTOR T CELLS, EXPANSION OF REGULATORY T-CELL SUBSETS EXPRESSING CXCR3 OR RETINOIC ACID-RELATED ORPHAN RECEPTOR GAMMAT, AND DEMETHYLATION OF THE FORKHEAD BOX P3 (FOXP3) LOCUS. THE COMPOSITION AND DIVERSITY OF THE GASTROINTESTINAL MICROBIOTA IS MEASURABLY AFFECTED BY PERINATAL H PYLORI EXPOSURE. CONCLUSION: WE CONCLUDE THAT EXPOSURE TO H PYLORI HAS CONSEQUENCES NOT ONLY FOR THE CARRIER BUT ALSO FOR SUBSEQUENT GENERATIONS THAT CAN BE EXPLOITED FOR INTERVENTIONAL PURPOSES. 2019 2 1077 25 CLONAL HEMATOPOIESIS OF INDETERMINATE POTENTIAL (CHIP): LINKING SOMATIC MUTATIONS, HEMATOPOIESIS, CHRONIC INFLAMMATION AND CARDIOVASCULAR DISEASE. CLONAL HEMATOPOIESIS OF INDETERMINATE POTENTIAL (CHIP) IS THE PRESENCE OF A CLONALLY EXPANDED HEMATOPOIETIC STEM CELL CAUSED BY A LEUKEMOGENIC MUTATION IN INDIVIDUALS WITHOUT EVIDENCE OF HEMATOLOGIC MALIGNANCY, DYSPLASIA, OR CYTOPENIA. CHIP IS ASSOCIATED WITH A 0.5-1.0% RISK PER YEAR OF LEUKEMIA. REMARKABLY, IT CONFERS A TWO-FOLD INCREASE IN CARDIOVASCULAR RISK INDEPENDENT OF TRADITIONAL RISK FACTORS. ROUGHLY 80% OF PATIENTS WITH CHIP HAVE MUTATIONS IN EPIGENETIC REGULATORS DNMT3A, TET2, ASXL1, DNA DAMAGE REPAIR GENES PPM1D, TP53, THE REGULATORY TYROSINE KINASE JAK2, OR MRNA SPLICEOSOME COMPONENTS SF3B1, AND SRSF2. CHIP IS ASSOCIATED WITH A PRO-INFLAMMATORY STATE THAT HAS BEEN LINKED TO CORONARY ARTERY DISEASE, MYOCARDIAL INFARCTION, AND VENOUS THROMBOEMBOLIC DISEASE, AS WELL AS PROGNOSIS AMONG THOSE WITH AORTIC STENOSIS AND HEART FAILURE. HERITABLE AND ACQUIRED RISK FACTORS ARE ASSOCIATED WITH INCREASED CHIP PREVALENCE, INCLUDING GERMLINE VARIATION, AGE, UNHEALTHY LIFESTYLE BEHAVIORS (I.E. SMOKING, OBESITY), INFLAMMATORY CONDITIONS, PREMATURE MENOPAUSE, HIV AND EXPOSURE TO CANCER THERAPIES. THIS REVIEW AIMS TO SUMMARIZE EMERGING RESEARCH ON CHIP, THE MECHANISMS UNDERLYING ITS IMPORTANT ROLE IN PROPAGATING INFLAMMATION AND ACCELERATING CARDIOVASCULAR DISEASE, AND NEW STUDIES DETAILING THE ROLE OF ASSOCIATED RISK FACTORS AND CO-MORBIDITIES THAT INCREASE CHIP PREVALENCE. 2021 3 384 25 AN EVOLUTIONARY PERSPECTIVE ON CHRONIC MYELOMONOCYTIC LEUKEMIA. CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) SHARES WITH OTHER MYELOID DISEASES A NUMBER OF SOMATIC GENE MUTATIONS. THESE MUTATIONS CAN NOW BE INTEGRATED WITHIN THE FRAMEWORK OF EVOLUTION THEORY TO ADDRESS THE MECHANISMS OF THE DISEASE. SEVERAL EVIDENCES INDICATE THAT THE DISEASE EMERGES IN ADULT HEMATOPOIETIC STEM CELLS (HSC) THROUGH THE AGE-DEPENDENT ACCUMULATION OF DNA DAMAGE, LEADING STOCHASTICALLY TO A DRIVER MUTATION THAT CONFERS A COMPETITIVE ADVANTAGE TO THE CELL. A MUTATION IN TET2 GENE COULD BE ONE OF THESE DRIVER MUTATIONS PROVOKING THE EMERGENCE OF CLONALITY. AFTER A LONG LATENCY, SECONDARY LESIONS, SUCH AS MUTATIONS IN THE SRSF2 GENE, CONTRIBUTE TO PROGRESSION TO FULL-BLOWN MALIGNANCY, WITH ABNORMAL DIFFERENTIATION. ADDITIONAL MUTATIONS ACCUMULATE AND BRANCHING ARISING MOSTLY THROUGH MITOTIC RECOMBINATION GENERATES CLONAL HETEROGENEITY. MODIFICATIONS IN THE MICROENVIRONMENT PROBABLY AFFECT THIS CLONAL DYNAMICS, WHEREAS EPIGENETIC ALTERATIONS, SUCH AS HYPERMETHYLATION OF THE TIF1GAMMA GENE PROMOTER, MAY GENERATE PHENOTYPIC DIVERSIFICATION OF OTHERWISE CLONAL POPULATIONS. THE PRESERVED ALTHOUGH DEREGULATED MYELOID DIFFERENTIATION THAT CHARACTERIZES CMML, WITH GRANULOMONOCYTE EXPANSION AND VARIOUS CYTOPENIAS, MAY DEPEND ON EARLY CLONAL DOMINANCE IN THE HEMATOPIETIC CELL HIERARCHY. PROGRESSION TO ACUTE MYELOID LEUKEMIA OBSERVED IN 25-30% OF THE PATIENTS MAY ARISE FROM THE MASSIVE EXPANSION OF A CLONE WITH NOVEL GENETIC LESIONS, PROVIDING A HIGH FITNESS TO PREVIOUSLY MINOR SUBCLONES WHEN IN CHRONIC PHASE OF THE DISEASE. THIS REVIEW DISCUSSES THE VARIOUS MODELS OF DISEASE EMERGENCE AND PROGRESSION AND HOW THIS RECENT KNOWLEDGE COULD DRIVE RATIONAL THERAPEUTIC STRATEGIES. 2013 4 2782 21 EZH2 INHIBITION CONFERS PIK3CA-DRIVEN LUNG TUMORS ENHANCED SENSITIVITY TO PI3K INHIBITION. MEMBERS OF THE PI3K SIGNALING PATHWAY, ESPECIALLY PIK3CA, THE GENE ENCODING THE CATALYTIC SUBUNIT OF THE PI3K COMPLEX, ARE HIGHLY MUTATED AND AMPLIFIED IN VARIOUS CANCER TYPES, INCLUDING NON-SMALL CELL LUNG CANCER. ALTHOUGH PI3K INHIBITORS HAVE BEEN USED IN CLINICS FOR FOLLICULAR LYMPHOMA AND CHRONIC LYMPHOCYTIC LEUKEMIA, NO AGENTS TARGETING PI3K ABERRATIONS IN LUNG CANCER HAVE BEEN APPROVED BY THE FDA SO FAR. IN THIS STUDY, WE OBSERVED THAT PIK3CA-E545K, THE MOST COMMON MUTATION IN LUNG CANCER, HARBORED A MODEST INDUCTION OF STEM-LIKE PROPERTIES IN LUNG EPITHELIAL CELLS, AND DROVE DEVELOPMENT OF ADENOCARCINOMA AUTOCHTHONOUSLY WHEN PAIRED WITH P53 LOSS IN A MURINE MOUSE MODEL. WE ALSO FOUND THAT PIK3CA-MUTANT OF AMPLIFIED LUNG CANCER CELLS WERE SENSITIVE TO EZH2 INHIBITION. EZH2 INHIBITION SYNERGIZED WITH PI3K INHIBITION IN HUMAN CANCER CELLS IN VITRO AND WORKED TOGETHER EFFICIENTLY IN VIVO. MECHANISTICALLY, EZH2 INHIBITION COOPERATED WITH PI3K INHIBITION TO PRODUCE A MORE POTENT SUPPRESSION OF PHOSPHO-AKT DOWNSTREAM OF PI3K. THIS STUDY SUGGESTS A PROMISING COMBINATION THERAPY TO COMBAT LUNG CANCERS WITH PIK3CA MUTATION OR AMPLIFICATION. BOTH COPANLISIB, THE PI3K INHIBITOR, AND TAZEMETOSTAT, THE EZH2 INHIBITOR, ARE FDA-APPROVED, WHICH SHOULD ENHANCE THE CLINICAL TRANSLATION OF THIS WORK. 2022 5 1076 26 CLONAL HEMATOPOIESIS IN MYELOPROLIFERATIVE NEOPLASMS CONFERS A PREDISPOSITION TO BOTH THROMBOSIS AND CANCER. PURPOSE OF REVIEW: THIS REVIEW FOCUSES ON VASCULAR COMPLICATIONS ASSOCIATED WITH CHRONIC MYELOPROLIFERATIVE NEOPLASMS (MPN) AND MORE SPECIFICALLY AIMS TO DISCUSS THE CLINICAL AND BIOLOGICAL EVIDENCE SUPPORTING THE EXISTENCE OF A LINK BETWEEN CLONAL HEMATOPOIESIS, CARDIOVASCULAR EVENTS (CVE), AND SOLID CANCER (SC). RECENT FINDINGS: THE MPN NATURAL HISTORY IS DRIVEN BY UNCONTROLLED CLONAL MYELOPROLIFERATION SUSTAINED BY ACQUIRED SOMATIC MUTATIONS IN DRIVER (JAK2, CALR, AND MPL) AND NON-DRIVER GENES, INVOLVING EPIGENETIC (E.G., TET2, DNMT3A) REGULATORS, CHROMATIN REGULATOR GENES (E.G., ASXL1, EZH2), AND SPLICING MACHINERY GENES (E.G., SF3B1). THE GENOMIC ALTERATIONS AND ADDITIONAL THROMBOSIS ACQUIRED RISK FACTORS ARE DETERMINANTS FOR CVE. THERE IS EVIDENCE THAT CLONAL HEMATOPOIESIS CAN ELICIT A CHRONIC AND SYSTEMIC INFLAMMATION STATUS THAT ACTS AS DRIVING FORCE FOR THE DEVELOPMENT OF THROMBOSIS, MPN EVOLUTION, AND SECOND CANCER (SC). THIS NOTION MAY EXPLAIN THE MECHANISM THAT LINKS ARTERIAL THROMBOSIS IN MPN PATIENTS AND SUBSEQUENT SOLID TUMORS. IN THE LAST DECADE, CLONAL HEMATOPOIESIS OF INDETERMINATE POTENTIAL (CHIP) HAS BEEN DETECTED IN THE GENERAL POPULATION PARTICULARLY IN THE ELDERLY AND INITIALLY FOUND IN MYOCARDIAL INFARCTION AND STROKE, RISING THE HYPOTHESIS THAT THE INFLAMMATORY STATUS CHIP-ASSOCIATED COULD CONFER PREDISPOSITION TO BOTH CARDIOVASCULAR DISEASES AND CANCER. IN SUMMARY, CLONAL HEMATOPOIESIS IN MPN AND CHIP CONFER A PREDISPOSITION TO CARDIOVASCULAR EVENTS AND CANCER THROUGH CHRONIC AND SYSTEMIC INFLAMMATION. THIS ACQUISITION COULD OPEN NEW AVENUES FOR ANTITHROMBOTIC THERAPY BOTH IN MPNS AND IN GENERAL POPULATION BY TARGETING BOTH CLONAL HEMATOPOIESIS AND INFLAMMATION. 2023 6 655 45 BLOCKADE OF IMMUNE-CHECKPOINT B7-H4 AND LYSINE DEMETHYLASE 5B IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA CONFERS PROTECTIVE IMMUNITY AGAINST P. GINGIVALIS INFECTION. PATHOGENS ARE CAPABLE OF HIJACKING IMMUNE DEFENSE MECHANISMS, THEREBY CREATING A TOLEROGENIC ENVIRONMENT FOR HYPERMUTATED MALIGNANT CELLS THAT ARISE WITHIN THE SITE OF INFECTION. IMMUNE CHECKPOINT-ORIENTED IMMUNOTHERAPIES HAVE SHOWN CONSIDERABLE PROMISE. EQUALLY IMPORTANT, THE EPIGENETIC REPROGRAMMING OF AN IMMUNE-EVASIVE PHENOTYPE THAT ACTIVATES THE IMMUNE SYSTEM IN A SYNERGISTIC MANNER CAN IMPROVE IMMUNOTHERAPY OUTCOMES. THESE ADVANCES HAVE LED TO COMBINATIONS OF EPIGENETIC- AND IMMUNE-BASED THERAPEUTICS. WE PREVIOUSLY DEMONSTRATED THAT PORPHYROMONAS GINGIVALIS ISOLATED FROM ESOPHAGEAL SQUAMOUS CELL CARCINOMA (ESCC) LESIONS REPRESENTS A MAJOR PATHOGEN ASSOCIATED WITH THIS DEADLY DISEASE. IN THIS STUDY, WE EXAMINED THE MECHANISMS ASSOCIATED WITH HOST IMMUNITY DURING P. GINGIVALIS INFECTION AND DEMONSTRATED THAT EXPERIMENTALLY INFECTED ESCC RESPONDS BY INCREASING THE EXPRESSION OF B7-H4 AND LYSINE DEMETHYLASE 5B, WHICH ALLOWED SUBSEQUENT IN VIVO ANALYSIS OF THE IMMUNOTHERAPEUTIC EFFECTS OF ANTI-B7-H4 AND HISTONE DEMETHYLASE INHIBITORS IN MODELS OF CHRONIC INFECTION AND IMMUNITY AGAINST XENOGRAFTED HUMAN TUMORS. USING THREE DIFFERENT PRECLINICAL MOUSE MODELS RECEIVING COMBINED THERAPY, WE SHOWED THAT MICE MOUNTED STRONG RESISTANCE AGAINST P. GINGIVALIS INFECTION AND TUMOR CHALLENGE. THIS MAY HAVE OCCURRED VIA GENERATION OF A T CELL-MEDIATED RESPONSE IN THE MICROENVIRONMENT AND FORMATION OF IMMUNE MEMORY. IN ESCC SUBJECTS, COEXPRESSION OF B7-H4 AND KDM5B CORRELATED MORE SIGNIFICANTLY WITH BACTERIAL LOAD THAN WITH THE EXPRESSION OF EITHER MOLECULE ALONE. THESE RESULTS HIGHLIGHT THE UNIQUE ABILITY OF P. GINGIVALIS TO EVADE IMMUNITY AND DEFINE POTENTIAL TARGETS THAT CAN BE EXPLOITED THERAPEUTICALLY TO IMPROVE THE CONTROL OF P. GINGIVALIS INFECTION AND THE DEVELOPMENT OF ASSOCIATED NEOPLASIA. 2019 7 4092 23 MATERNAL REPETITIVE HYPOXIA PRIOR TO MATING CONFERS EPIGENETIC RESILIENCE TO MEMORY IMPAIRMENT IN MALE PROGENY. WE SHOWED PREVIOUSLY IN A MOUSE MODEL OF VASCULAR COGNITIVE IMPAIRMENT AND DEMENTIA INVOLVING CHRONIC CEREBRAL HYPOPERFUSION (CCH) THAT REPETITIVE HYPOXIC CONDITIONING (RHC) OF BOTH PARENTS RESULTS IN THE EPIGENETIC, INTERGENERATIONAL TRANSMISSION OF RESILIENCE TO RECOGNITION MEMORY LOSS IN ADULT PROGENY, AS ASSESSED BY THE NOVEL OBJECT RECOGNITION TEST. THE PRESENT STUDY WAS UNDERTAKEN IN THE SAME MODEL TO DETERMINE WHETHER RHC TREATMENT OF ONE OR BOTH PARENTS IS REQUIRED TO CONFER DEMENTIA RESILIENCE INTERGENERATIONALLY. WE FOUND INHERITED RESILIENCE TO 3 MONTHS OF CCH IN MALES IS MATERNALLY MEDIATED (P = .006). STATISTICALLY, WE OBSERVED A STRONG TREND FOR THE PATERNAL GERMLINE TO CONTRIBUTE AS WELL (P = .052). WE ALSO FOUND THAT, IN CONTRAST TO WHAT IS WIDELY OBSERVED IN MALES, FEMALES DISPLAY INTACT RECOGNITION MEMORY (P = .001) AFTER 3 MONTHS OF CCH, REVEALING A HERETOFORE UNIDENTIFIED SEXUAL DIMORPHISM WITH RESPECT TO COGNITIVE IMPACT DURING DISEASE PROGRESSION. OVERALL, RESULTS OF OUR STUDY STRONGLY IMPLICATE EPIGENETIC CHANGES IN MATERNAL GERM CELLS, INDUCED BY OUR REPETITIVE SYSTEMIC HYPOXIC STIMULUS, CONTRIBUTING TO A MODIFIED DIFFERENTIATION PROGRAM CAPABLE OF ESTABLISHING A DEMENTIA-RESILIENT PHENOTYPE IN ADULT MALE FIRST-GENERATION PROGENY. (PSYCINFO DATABASE RECORD (C) 2023 APA, ALL RIGHTS RESERVED). 2023 8 926 31 CHRONIC INFLAMMATION PATHWAY NF-KAPPAB COOPERATES WITH EPIGENETIC REPROGRAMMING TO DRIVE THE MALIGNANT PROGRESSION OF GLIOBLASTOMA. WITHOUT AN EFFECTIVE STRATEGY FOR TARGETED THERAPY, GLIOBLASTOMA IS STILL INCURABLE WITH A MEDIAN SURVIVAL OF ONLY 15 MONTHS. BOTH CHRONIC INFLAMMATION AND EPIGENETIC REPROGRAMMING ARE HALLMARKS OF CANCER. HOWEVER, THE MECHANISMS AND CONSEQUENCES OF THEIR COOPERATION IN GLIOBLASTOMA REMAIN UNKNOWN. HERE, WE DISCOVER THAT CHRONIC INFLAMMATION GOVERNS H3K27ME3 REPROGRAMMING IN GLIOBLASTOMA THROUGH THE CANONICAL NF-KAPPAB PATHWAY TO TARGET EZH2. BEING A CRUCIAL MEDIATOR OF CHRONIC INFLAMMATION, THE CANONICAL NF-KAPPAB SIGNALLING SPECIFICALLY DIRECTS THE EXPRESSION AND REDISTRIBUTION OF H3K27ME3 BUT NOT H3K4ME3, H3K9ME3 AND H3K36ME3. USING RNA-SEQ SCREENING TO FOCUS ON GENES ENCODING METHYLTRANSFERASES AND DEMETHYLASES OF HISTONE, WE IDENTIFY EZH2 AS A KEY METHYLTRANSFERASE TO CONTROL INFLAMMATION-TRIGGERED EPIGENETIC REPROGRAMMING IN GLIOMAGENESIS. MECHANISTICALLY, NF-KAPPAB SELECTIVELY DRIVES THE EXPRESSION OF EZH2 BY ACTIVATING ITS TRANSCRIPTION, CONSEQUENTLY RESULTING IN A GLOBAL CHANGE IN H3K27ME3 EXPRESSION AND DISTRIBUTION. FURTHERMORE, WE FIND THAT CO-ACTIVATION OF NF-KAPPAB AND EZH2 CONFERS THE POOREST CLINICAL OUTCOME, AND THAT THE RISK FOR GLIOBLASTOMA CAN BE ACCURATELY MOLECULARLY STRATIFIED BY NF-KAPPAB AND EZH2. IT IS NOTABLE THAT NF-KAPPAB CAN POTENTIALLY COOPERATE WITH EZH2 IN MORE THAN ONE WAY, AND MOST IMPORTANTLY, WE DEMONSTRATE A SYNERGISTIC EFFECT OF CANCER CELLS INDUCED BY COMBINATORY INHIBITION OF NF-KAPPAB AND EZH2, WHICH BOTH ARE FREQUENTLY OVER-ACTIVATED IN GLIOBLASTOMA. IN SUMMARY, WE UNCOVER A FUNCTIONAL COOPERATION BETWEEN CHRONIC INFLAMMATION AND EPIGENETIC REPROGRAMMING IN GLIOBLASTOMA, COMBINED TARGETING OF WHICH BY INHIBITORS GUARANTEED IN SAFETY AND AVAILABILITY FURNISHES A POTENT STRATEGY FOR EFFECTIVE TREATMENT OF THIS FATAL DISEASE. 2022 9 6129 30 THE EPIGENETIC REGULATION OF PODOCYTE FUNCTION IN DIABETES. CHRONIC HYPERGLYCEMIA EARLY IN THE COURSE OF DIABETES CONFERS A SUSTAINED INCREASE IN THE RISK OF COMPLICATIONS DEVELOPMENT. IN RECENT YEARS, EFFORTS TO UNDERSTAND THE MOLECULAR BASIS FOR THIS "METABOLIC MEMORY" HAVE FOCUSED ON EPIGENETIC MECHANISMS AS A MEANS BY WHICH TRANSIENT HIGH GLUCOSE CAN CAUSE PERSISTENT AND PROPAGATED CHANGES IN CELL FUNCTION. FOR INSTANCE, IN VASCULAR ENDOTHELIAL CELLS, SMOOTH MUSCLE CELLS AND PERIPHERAL BLOOD CELLS, TEMPORARY EXPOSURE TO HIGH GLUCOSE CAUSES CHANGES IN EPIGENETIC MARKS THAT PROMOTE A SHIFT TOWARDS A PRO-INFLAMMATORY PHENOTYPE. HOWEVER, THE INFLUENCE OF EPIGENETIC PROCESSES IN COMPLICATIONS DEVELOPMENT EXTENDS BEYOND THEIR CONTRIBUTION TO METABOLIC MEMORY. PODOCYTES, FOR EXAMPLE, ARE TERMINALLY DIFFERENTIATED CELLS OF THE RENAL GLOMERULUS WHOSE INJURY IS A MAJOR CONTRIBUTOR TO THE PATHOGENESIS OF NEPHROPATHY. OVER RECENT MONTHS, SEVERAL REPORTS HAVE EMERGED DESCRIBING THE ESSENTIAL ACTIONS OF HISTONE-MODIFYING ENZYMES AND DNA METHYLATION PATTERNS (THE TWO PRINCIPAL EPIGENETIC MECHANISMS) IN MAINTAINING PODOCYTE INTEGRITY, ESPECIALLY UNDER DIABETIC CONDITIONS. HERE, WE REVIEW THE KNOWN AND POTENTIAL ROLE OF EPIGENETIC PROCESSES WITHIN PODOCYTES, FOCUSING ON THE EVIDENCE LINKING THESE PROCESSES TO OXIDATIVE STRESS, CROSSTALK WITH TUBULE CELLS, AUTOPHAGY AND SLIT-PORE PROTEIN EXPRESSION. WHETHER PODOCYTES THEMSELVES EXHIBIT A METABOLIC MEMORY AWAITS TO BE SEEN. 2015 10 923 24 CHRONIC INFECTION DRIVES DNMT3A-LOSS-OF-FUNCTION CLONAL HEMATOPOIESIS VIA IFNGAMMA SIGNALING. AGE-RELATED CLONAL HEMATOPOIESIS (CH) IS A RISK FACTOR FOR MALIGNANCY, CARDIOVASCULAR DISEASE, AND ALL-CAUSE MORTALITY. SOMATIC MUTATIONS IN DNMT3A ARE DRIVERS OF CH, BUT DECADES MAY ELAPSE BETWEEN THE ACQUISITION OF A MUTATION AND CH, SUGGESTING THAT ENVIRONMENTAL FACTORS CONTRIBUTE TO CLONAL EXPANSION. WE TESTED WHETHER INFECTION PROVIDES SELECTIVE PRESSURE FAVORING THE EXPANSION OF DNMT3A MUTANT HEMATOPOIETIC STEM CELLS (HSCS) IN MOUSE CHIMERAS. WE CREATED DNMT3A-MOSAIC MICE BY TRANSPLANTING DNMT3A(-/-) AND WT HSCS INTO WT MICE AND OBSERVED THE SUBSTANTIAL EXPANSION OF DNMT3A(-/-) HSCS DURING CHRONIC MYCOBACTERIAL INFECTION. INJECTION OF RECOMBINANT IFNGAMMA ALONE WAS SUFFICIENT TO PHENOCOPY CH BY DNMT3A(-/-) HSCS UPON INFECTION. TRANSCRIPTIONAL AND EPIGENETIC PROFILING AND FUNCTIONAL STUDIES INDICATE REDUCED DIFFERENTIATION ASSOCIATED WITH WIDESPREAD METHYLATION ALTERATIONS, AND REDUCED SECONDARY STRESS-INDUCED APOPTOSIS ACCOUNTS FOR DNMT3A(-/-) CLONAL EXPANSION DURING INFECTION. DNMT3A MUTANT HUMAN HSCS SIMILARLY EXHIBIT DEFECTIVE IFNGAMMA-INDUCED DIFFERENTIATION. WE THUS DEMONSTRATE THAT IFNGAMMA SIGNALING INDUCED DURING CHRONIC INFECTION CAN DRIVE DNMT3A-LOSS-OF-FUNCTION CH. 2021 11 2367 29 EPIGENETIC REGULATION OF T CELL EXHAUSTION. CHRONIC ANTIGEN STIMULATION DURING VIRAL INFECTIONS AND CANCER CAN LEAD TO T CELL EXHAUSTION, WHICH IS CHARACTERIZED BY REDUCED EFFECTOR FUNCTION AND PROLIFERATION, AND THE EXPRESSION OF INHIBITORY IMMUNE CHECKPOINT RECEPTORS. RECENT STUDIES HAVE DEMONSTRATED THAT T CELL EXHAUSTION RESULTS IN WHOLESCALE EPIGENETIC REMODELING THAT CONFERS PHENOTYPIC STABILITY TO THESE CELLS AND PREVENTS T CELL REINVIGORATION BY CHECKPOINT BLOCKADE. HERE, WE REVIEW FOUNDATIONAL TECHNOLOGIES TO PROFILE THE EPIGENOME AT MULTIPLE SCALES, INCLUDING MAPPING THE LOCATIONS OF TRANSCRIPTION FACTORS AND HISTONE MODIFICATIONS, DNA METHYLATION AND THREE-DIMENSIONAL GENOME CONFORMATION. WE DISCUSS HOW THESE TECHNOLOGIES HAVE ELUCIDATED THE DEVELOPMENT AND EPIGENETIC REGULATION OF EXHAUSTED T CELLS AND FUNCTIONAL IMPLICATIONS ACROSS VIRAL INFECTION, CANCER, AUTOIMMUNITY AND ENGINEERED T CELL THERAPIES. FINALLY, WE COVER EMERGING MULTI-OMIC AND GENOME ENGINEERING TECHNOLOGIES, CURRENT AND UPCOMING OPPORTUNITIES TO APPLY THESE TO T CELL EXHAUSTION, AND THERAPEUTIC OPPORTUNITIES FOR T CELL ENGINEERING IN THE CLINIC. 2022 12 1075 27 CLONAL HEMATOPOIESIS DRIVEN BY DNMT3A AND TET2 MUTATIONS: ROLE IN MONOCYTE AND MACROPHAGE BIOLOGY AND ATHEROSCLEROTIC CARDIOVASCULAR DISEASE. PURPOSE OF REVIEW: CLONAL HEMATOPOIESIS OF INDETERMINATE POTENTIAL (CHIP), DEFINED BY THE PRESENCE OF SOMATIC MUTATIONS IN HEMATOPOIETIC CELLS, IS ASSOCIATED WITH ADVANCED AGE AND INCREASED MORTALITY DUE TO CARDIOVASCULAR DISEASE. GENE MUTATIONS IN DNMT3A AND TET2 ARE THE MOST FREQUENTLY IDENTIFIED VARIANTS AMONG PATIENTS WITH CHIP AND PROVIDE SELECTIVE ADVANTAGE THAT SPURS CLONAL EXPANSION AND MYELOID SKEWING. ALTHOUGH DNMT3A AND TET2 APPEAR TO HAVE OPPOSING ENZYMATIC INFLUENCE ON DNA METHYLATION, MOUNTING DATA HAS CHARACTERIZED CONVERGENT INFLAMMATORY PATHWAYS, PROVIDING INSIGHTS TO HOW CHIP MAY MEDIATE ATHEROSCLEROTIC CARDIOVASCULAR DISEASE (ASCVD). RECENT FINDINGS: WE REVIEW A MULTITUDE OF STUDIES THAT CHARACTERIZE ABERRANT INFLAMMATORY SIGNALING AS RESULT OF DNMT3A AND TET2 DEFICIENCY IN MONOCYTES AND MACROPHAGES, IMMUNE CELLS WITH PROMINENT ROLES IN ATHEROSCLEROSIS. ALTHOUGH SPECIFIC DNA METHYLATION SIGNATURES ASSOCIATED WITH THESE KNOWN EPIGENETIC REGULATORS HAVE BEEN IDENTIFIED, MANY STUDIES HAVE ALSO CHARACTERIZED DIVERSE MODULATORY FUNCTIONS OF DNTM3A AND TET2 THAT URGE CELL AND CONTEXT-SPECIFIC EXPERIMENTAL STUDIES TO FURTHER DEFINE HOW DNMT3A AND TET2 MAY NONENZYMATICALLY ACTIVATE INFLAMMATORY PATHWAYS WITH CLINICALLY MEANINGFUL CONSEQUENCES. SUMMARY: CHIP, COMMON IN ELDERLY INDIVIDUALS, PROVIDES AN OPPORTUNITY UNDERSTAND AND POTENTIALLY MODIFY AGE-RELATED CHRONIC INFLAMMATORY ASCVD RISK. 2022 13 1468 27 DISTINCT EPIGENETIC PROGRAMS REGULATE CARDIAC MYOCYTE DEVELOPMENT AND DISEASE IN THE HUMAN HEART IN VIVO. EPIGENETIC MECHANISMS AND TRANSCRIPTION FACTOR NETWORKS ESSENTIAL FOR DIFFERENTIATION OF CARDIAC MYOCYTES HAVE BEEN UNCOVERED. HOWEVER, RESHAPING OF THE EPIGENOME OF THESE TERMINALLY DIFFERENTIATED CELLS DURING FETAL DEVELOPMENT, POSTNATAL MATURATION, AND IN DISEASE REMAINS UNKNOWN. HERE, WE INVESTIGATE THE DYNAMICS OF THE CARDIAC MYOCYTE EPIGENOME DURING DEVELOPMENT AND IN CHRONIC HEART FAILURE. WE FIND THAT PRENATAL DEVELOPMENT AND POSTNATAL MATURATION ARE CHARACTERIZED BY A COOPERATION OF ACTIVE CPG METHYLATION AND HISTONE MARKS AT CIS-REGULATORY AND GENIC REGIONS TO SHAPE THE CARDIAC MYOCYTE TRANSCRIPTOME. IN CONTRAST, PATHOLOGICAL GENE EXPRESSION IN TERMINAL HEART FAILURE IS ACCOMPANIED BY CHANGES IN ACTIVE HISTONE MARKS WITHOUT MAJOR ALTERATIONS IN CPG METHYLATION AND REPRESSIVE CHROMATIN MARKS. NOTABLY, CIS-REGULATORY REGIONS IN CARDIAC MYOCYTES ARE SIGNIFICANTLY ENRICHED FOR CARDIOVASCULAR DISEASE-ASSOCIATED VARIANTS. THIS STUDY UNCOVERS DISTINCT LAYERS OF EPIGENETIC REGULATION NOT ONLY DURING PRENATAL DEVELOPMENT AND POSTNATAL MATURATION BUT ALSO IN DISEASED HUMAN CARDIAC MYOCYTES. 2018 14 5985 37 TET2-MEDIATED CLONAL HEMATOPOIESIS ACCELERATES HEART FAILURE THROUGH A MECHANISM INVOLVING THE IL-1BETA/NLRP3 INFLAMMASOME. BACKGROUND: RECENT STUDIES HAVE SHOWN THAT HEMATOPOIETIC STEM CELLS CAN UNDERGO CLONAL EXPANSION SECONDARY TO SOMATIC MUTATIONS IN LEUKEMIA-RELATED GENES, THUS LEADING TO AN AGE-DEPENDENT ACCUMULATION OF MUTANT LEUKOCYTES IN THE BLOOD. THIS SOMATIC MUTATION-RELATED CLONAL HEMATOPOIESIS IS COMMON IN HEALTHY OLDER INDIVIDUALS, BUT IT HAS BEEN ASSOCIATED WITH AN INCREASED INCIDENCE OF FUTURE CARDIOVASCULAR DISEASE. THE EPIGENETIC REGULATOR TET2 IS FREQUENTLY MUTATED IN BLOOD CELLS OF INDIVIDUALS EXHIBITING CLONAL HEMATOPOIESIS. OBJECTIVES: THIS STUDY INVESTIGATED WHETHER TET2 MUTATIONS WITHIN HEMATOPOIETIC CELLS CAN CONTRIBUTE TO HEART FAILURE IN 2 MODELS OF CARDIAC INJURY. METHODS: HEART FAILURE WAS INDUCED IN MICE BY PRESSURE OVERLOAD, ACHIEVED BY TRANSVERSE AORTIC CONSTRICTION OR CHRONIC ISCHEMIA INDUCED BY THE PERMANENT LIGATION OF THE LEFT ANTERIOR DESCENDING ARTERY. COMPETITIVE BONE MARROW TRANSPLANTATION STRATEGIES WITH TET2-DEFICIENT CELLS WERE USED TO MIMIC TET2 MUTATION-DRIVEN CLONAL HEMATOPOIESIS. ALTERNATIVELY, TET2 WAS SPECIFICALLY ABLATED IN MYELOID CELLS USING CRE RECOMBINASE EXPRESSED FROM THE LYSM PROMOTER. RESULTS: IN BOTH EXPERIMENTAL HEART FAILURE MODELS, HEMATOPOIETIC OR MYELOID TET2 DEFICIENCY WORSENED CARDIAC REMODELING AND FUNCTION, IN PARALLEL WITH INCREASED INTERLEUKIN-1BETA (IL-1BETA) EXPRESSION. TREATMENT WITH A SELECTIVE NLRP3 INFLAMMASOME INHIBITOR PROTECTED AGAINST THE DEVELOPMENT OF HEART FAILURE AND ELIMINATED THE DIFFERENCES IN CARDIAC PARAMETERS BETWEEN TET2-DEFICIENT AND WILD-TYPE MICE. CONCLUSIONS: TET2 DEFICIENCY IN HEMATOPOIETIC CELLS IS ASSOCIATED WITH GREATER CARDIAC DYSFUNCTION IN MURINE MODELS OF HEART FAILURE AS A RESULT OF ELEVATED IL-1BETA SIGNALING. THESE DATA SUGGEST THAT INDIVIDUALS WITH TET2-MEDIATED CLONAL HEMATOPOIESIS MAY BE AT GREATER RISK OF DEVELOPING HEART FAILURE AND RESPOND BETTER TO IL-1BETA-NLRP3 INFLAMMASOME INHIBITION. 2018 15 1313 33 DELETING DNMT3A IN CAR T CELLS PREVENTS EXHAUSTION AND ENHANCES ANTITUMOR ACTIVITY. CHIMERIC ANTIGEN RECEPTOR (CAR) T CELL THERAPY IS REVOLUTIONIZING CANCER IMMUNOTHERAPY FOR PATIENTS WITH B CELL MALIGNANCIES AND IS NOW BEING DEVELOPED FOR SOLID TUMORS AND CHRONIC VIRAL INFECTIONS. ALTHOUGH CLINICAL TRIALS HAVE DEMONSTRATED THE CURATIVE POTENTIAL OF CAR T CELL THERAPY, A SUBSTANTIAL AND WELL-ESTABLISHED LIMITATION IS THE HEIGHTENED CONTRACTION AND TRANSIENT PERSISTENCE OF CAR T CELLS DURING PROLONGED ANTIGEN EXPOSURE. THE UNDERLYING MECHANISM(S) FOR THIS DYSFUNCTIONAL STATE, OFTEN TERMED CAR T CELL EXHAUSTION, REMAINS POORLY DEFINED. HERE, WE REPORT THAT EXHAUSTION OF HUMAN CAR T CELLS OCCURS THROUGH AN EPIGENETIC REPRESSION OF THE T CELL'S MULTIPOTENT DEVELOPMENTAL POTENTIAL. DELETION OF THE DE NOVO DNA METHYLTRANSFERASE 3 ALPHA (DNMT3A) IN T CELLS EXPRESSING FIRST- OR SECOND-GENERATION CARS UNIVERSALLY PRESERVED THE CELLS' ABILITY TO PROLIFERATE AND MOUNT AN ANTITUMOR RESPONSE DURING PROLONGED TUMOR EXPOSURE. THE INCREASED FUNCTIONALITY OF THE EXHAUSTION-RESISTANT DNMT3A KNOCKOUT CAR T CELLS WAS COUPLED TO AN UP-REGULATION OF INTERLEUKIN-10, AND GENOME-WIDE DNA METHYLATION PROFILING DEFINED AN ATLAS OF GENES TARGETED FOR EPIGENETIC SILENCING. THIS ATLAS PROVIDES A MOLECULAR DEFINITION OF CAR T CELL EXHAUSTION, WHICH INCLUDES MANY TRANSCRIPTIONAL REGULATORS THAT LIMIT THE "STEMNESS" OF IMMUNE CELLS, INCLUDING CD28, CCR7, TCF7, AND LEF1. LAST, WE DEMONSTRATE THAT THIS EPIGENETICALLY REGULATED MULTIPOTENCY PROGRAM IS FIRMLY COUPLED TO THE CLINICAL OUTCOME OF PRIOR CAR T CELL THERAPIES. THESE DATA DOCUMENT THE CRITICAL ROLE EPIGENETIC MECHANISMS PLAY IN LIMITING THE FATE POTENTIAL OF HUMAN T CELLS AND PROVIDE A ROAD MAP FOR LEVERAGING THIS INFORMATION FOR IMPROVING CAR T CELL EFFICACY. 2021 16 4050 32 MALADAPTIVE TRAINED IMMUNITY AND CLONAL HEMATOPOIESIS AS POTENTIAL MECHANISTIC LINKS BETWEEN PERIODONTITIS AND INFLAMMATORY COMORBIDITIES. PERIODONTITIS IS BIDIRECTIONALLY ASSOCIATED WITH SYSTEMIC INFLAMMATORY DISORDERS. THE PREVALENCE AND SEVERITY OF THIS ORAL DISEASE AND LINKED COMORBIDITIES INCREASES WITH AGING. HERE, WE REVIEW TWO NEWLY EMERGED CONCEPTS, TRAINED INNATE IMMUNITY (TII) AND CLONAL HEMATOPOIESIS OF INDETERMINATE POTENTIAL (CHIP), WHICH TOGETHER SUPPORT A POTENTIAL HYPOTHESIS ON HOW PERIODONTITIS AFFECTS AND IS AFFECTED BY COMORBIDITIES AND WHY THE SUSCEPTIBILITY TO PERIODONTITIS AND COMORBIDITIES INCREASES WITH AGING. GIVEN THAT CHRONIC DISEASES ARE LARGELY TRIGGERED BY THE ACTION OF INFLAMMATORY IMMUNE CELLS, MODULATION OF THEIR BONE MARROW PRECURSORS, THE HEMATOPOIETIC STEM AND PROGENITOR CELLS (HSPCS), MAY AFFECT MULTIPLE DISORDERS THAT EMERGE AS COMORBIDITIES. SUCH ALTERATIONS IN HSPCS CAN BE MEDIATED BY TII AND/OR CHIP, TWO NON-MUTUALLY EXCLUSIVE PROCESSES SHARING A BIAS FOR ENHANCED MYELOPOIESIS AND PRODUCTION OF INNATE IMMUNE CELLS WITH HEIGHTENED PROINFLAMMATORY POTENTIAL. TII IS A STATE OF ELEVATED IMMUNE RESPONSIVENESS BASED ON INNATE IMMUNE (EPIGENETIC) MEMORY. SYSTEMIC INFLAMMATION CAN INITIATE TII IN THE BONE MARROW VIA SUSTAINED REWIRING OF HSPCS, WHICH THEREBY DISPLAY A SKEWING TOWARD THE MYELOID LINEAGE, RESULTING IN GENERATION OF HYPER-REACTIVE OR "TRAINED" MYELOID CELLS. CHIP ARISES FROM AGING-RELATED SOMATIC MUTATIONS IN HSPCS, WHICH CONFER A SURVIVAL AND PROLIFERATION ADVANTAGE TO THE MUTANT HSPCS AND GIVE RISE TO AN OUTSIZED FRACTION OF HYPER-INFLAMMATORY MUTANT MYELOID CELLS IN THE CIRCULATION AND TISSUES. THIS REVIEW DISCUSSES EMERGING EVIDENCE THAT SUPPORTS THE NOTION THAT TII AND CHIP MAY UNDERLIE A CAUSAL AND AGE-RELATED ASSOCIATION BETWEEN PERIODONTITIS AND COMORBIDITIES. A HOLISTIC MECHANISTIC UNDERSTANDING OF THE PERIODONTITIS-SYSTEMIC DISEASE CONNECTION MAY OFFER NOVEL DIAGNOSTIC AND THERAPEUTIC TARGETS FOR TREATING INFLAMMATORY COMORBIDITIES. 2022 17 2660 34 EPITHERAPY AND IMMUNE CHECKPOINT BLOCKADE: USING EPIGENETIC REINVIGORATION OF EXHAUSTED AND DYSFUNCTIONAL T CELLS TO REIMBURSE IMMUNOTHERAPY RESPONSE. BACKGROUND: CANCER CELLS SUBVERT NATURAL IMMUNOSUPPRESSION BY UPREGULATING THE EXPRESSION OF CHECKPOINT PROTEINS AND THEIR LIGANDS. FOR EXAMPLE, TUMOR CELLS EXPRESSING PROGRAMMED DEATH-LIGAND 1 (PD-L1) INDUCE IMMUNE CELL TOLERANCE TO CANCERS, THEREBY FACILITATING TUMOR PROGRESSION. THE RECENT CLINICAL SUCCESS OF IMMUNOTHERAPY, PARTICULARLY CHECKPOINT BLOCKADE, REPRESENTS A SIGNIFICANT ADVANCE IN CANCER THERAPY. HOWEVER, MANY CANCERS DEVELOP RESISTANCE TO IMMUNOTHERAPIES, AND THE UNDERLYING MECHANISMS AND HOW THESE MIGHT BE EXPLOITED TO OVERCOME RESISTANCE STILL NEED TO BE DETERMINED. METHODS: T CELL DYSFUNCTION, IN PART CAUSED BY CHRONIC T CELL RECEPTOR STIMULATION, DIMINISHES THE CAPACITY FOR DURABLE RESPONSES TO CHECKPOINT BLOCKADE. FURTHERMORE, T CELL POPULATIONS ARE PHENOTYPICALLY AND FUNCTIONALLY HETEROGENEOUS, RESULTING IN VARYING RESPONSES TO CHECKPOINT BLOCKADE. RECENT MOLECULAR STUDIES OF T CELL HETEROGENEITY HAVE SHOWN THAT CHECKPOINT BLOCKADE ON ITS OWN DOES NOT ALTER THE EPIGENETIC LANDSCAPE OF T CELLS, DESPITE EPIGENETIC CHANGES GOVERNING T CELL PHENOTYPE. CONCLUSION: HERE WE ARGUE THAT EPIGENETIC MODIFIERS CAN BE USED TO PRIME AND SENSITIZE T CELLS TO IMMUNOTHERAPY. ADMINISTERING EPITHERAPY IN CONJUNCTION WITH CHECKPOINT BLOCKADE COULD DECREASE T CELL EXHAUSTION AND IMMUNOTHERAPY RESISTANCE IN MANY CANCER TYPES. 2020 18 6812 31 [EPIGENETICS, INTERFACE BETWEEN ENVIRONMENT AND GENES: ROLE IN COMPLEX DISEASES]. EPIGENETICS IS THE STUDY OF HERITABLE CHANGES IN GENE EXPRESSION OR CELLULAR PHENOTYPE CAUSED BY MECHANISMS OTHER THAN CHANGES IN THE UNDERLYING DNA SEQUENCE. EPIGENETICS IS ONE OF THE MAJOR MECHANISMS EXPLAINING THE "DEVELOPMENTAL ORIGIN OF HEALTH AND DISEASES" (DOHAD). BESIDES GENETIC BACKGROUND INHERITED FROM PARENTS, WHICH CONFERS SUSCEPTIBILITY TO CERTAIN PATHOLOGIES, EPIGENETIC CHANGES CONSTITUTE THE MEMORY OF PREVIOUS EVENTS, EITHER POSITIVE OR NEGATIVE, ALONG THE LIFE CYCLE, INCLUDING AT THE IN UTERO STAGE. THE LATER EXPOSITION TO HOSTILE ENVIRONMENT MAY REVEAL SUCH SUSCEPTIBILITY, WITH THE DEVELOPMENT OF VARIOUS PATHOLOGIES, AMONG THEM NUMEROUS CHRONIC COMPLEX DISEASES. THE DEMONSTRATION OF SUCH A SEQUENCE OF EVENTS HAS BEEN SHOWN FOR METABOLIC DISEASES AS OBESITY, METABOLIC SYNDROME AND TYPE 2 DIABETES, CARDIOVASCULAR DISEASE AND CANCER. IN CONTRAST TO GENETIC PREDISPOSITION, WHICH IS IRREVERSIBLE, EPIGENETIC CHANGES ARE POTENTIALLY REVERSIBLE, THUS GIVING TARGETS NOT ONLY FOR PREVENTION, BUT POSSIBLY ALSO FOR THE TREATMENT OF CERTAIN COMPLEX DISEASES. 2012 19 590 27 BET BROMODOMAIN PROTEIN INHIBITION REVERSES CHIMERIC ANTIGEN RECEPTOR EXTINCTION AND REINVIGORATES EXHAUSTED T CELLS IN CHRONIC LYMPHOCYTIC LEUKEMIA. CHIMERIC ANTIGEN RECEPTOR (CAR) T CELLS HAVE INDUCED REMARKABLE ANTITUMOR RESPONSES IN B CELL MALIGNANCIES. SOME PATIENTS DO NOT RESPOND BECAUSE OF T CELL DEFICIENCIES THAT HAMPER THE EXPANSION, PERSISTENCE, AND EFFECTOR FUNCTION OF THESE CELLS. WE USED LONGITUDINAL IMMUNE PROFILING TO IDENTIFY PHENOTYPIC AND PHARMACODYNAMIC CHANGES IN CD19-DIRECTED CAR T CELLS IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). CAR EXPRESSION MAINTENANCE WAS ALSO INVESTIGATED BECAUSE THIS CAN AFFECT RESPONSE DURABILITY. CAR T CELL FAILURE WAS ACCOMPANIED BY PREEXISTING T CELL-INTRINSIC DEFECTS OR DYSFUNCTION ACQUIRED AFTER INFUSION. IN A SMALL SUBSET OF PATIENTS, CAR SILENCING WAS OBSERVED COINCIDENT WITH LEUKEMIA RELAPSE. USING A SMALL MOLECULE INHIBITOR, WE DEMONSTRATED THAT THE BROMODOMAIN AND EXTRA-TERMINAL (BET) FAMILY OF CHROMATIN ADAPTERS PLAYS A ROLE IN DOWNREGULATING CAR EXPRESSION. BET PROTEIN BLOCKADE ALSO AMELIORATED CAR T CELL EXHAUSTION AS MANIFESTED BY INHIBITORY RECEPTOR REDUCTION, ENHANCED METABOLIC FITNESS, INCREASED PROLIFERATIVE CAPACITY, AND ENRICHED TRANSCRIPTOMIC SIGNATURES OF T CELL REINVIGORATION. BET INHIBITION DECREASED LEVELS OF THE TET2 METHYLCYTOSINE DIOXYGENASE, AND FORCED EXPRESSION OF THE TET2 CATALYTIC DOMAIN ELIMINATED THE POTENCY-ENHANCING EFFECTS OF BET PROTEIN TARGETING IN CAR T CELLS, PROVIDING A MECHANISM LINKING BET PROTEINS AND T CELL DYSFUNCTION. THUS, MODULATING BET EPIGENETIC READERS MAY IMPROVE THE EFFICACY OF CELL-BASED IMMUNOTHERAPIES. 2021 20 3651 26 INCREASING COMPLEXITY OF MOLECULAR LANDSCAPES IN HUMAN HEMATOPOIETIC STEM AND PROGENITOR CELLS DURING DEVELOPMENT AND AGING. THE PAST FIVE DECADES HAVE SEEN SIGNIFICANT PROGRESS IN OUR UNDERSTANDING OF HUMAN HEMATOPOIESIS. THIS HAS IN PART BEEN DUE TO THE UNPRECEDENTED DEVELOPMENT OF ADVANCED TECHNOLOGIES, WHICH HAVE ALLOWED THE IDENTIFICATION AND CHARACTERIZATION OF RARE SUBSETS OF HUMAN HEMATOPOIETIC STEM AND PROGENITOR CELLS AND THEIR LINEAGE TRAJECTORIES FROM EMBRYONIC THROUGH TO ADULT LIFE. ADDITIONALLY, SURROGATE IN VITRO AND IN VIVO MODELS, ALTHOUGH NOT FULLY RECAPITULATING HUMAN HEMATOPOIESIS, HAVE SPURRED ON THESE SCIENTIFIC ADVANCES. THESE APPROACHES HAVE HEIGHTENED OUR KNOWLEDGE OF HEMATOLOGICAL DISORDERS AND DISEASES AND HAVE LED TO THEIR IMPROVED DIAGNOSIS AND THERAPIES. HERE, WE REVIEW HUMAN HEMATOPOIESIS AT EACH END OF THE AGE SPECTRUM, DURING EMBRYONIC AND FETAL DEVELOPMENT AND ON AGING, PROVIDING EXEMPLARS OF RECENT PROGRESS IN DECIPHERING THE INCREASINGLY COMPLEX CELLULAR AND MOLECULAR HEMATOPOIETIC LANDSCAPES IN HEALTH AND DISEASE. THIS REVIEW CONCLUDES BY HIGHLIGHTING LINKS BETWEEN CHRONIC INFLAMMATION AND METABOLIC AND EPIGENETIC CHANGES ASSOCIATED WITH AGING AND IN THE DEVELOPMENT OF CLONAL HEMATOPOIESIS. 2022