1 3281 115 HETEROGENEOUS TFH CELL POPULATIONS THAT DEVELOP DURING ENTERIC HELMINTH INFECTION PREDICT THE QUALITY OF TYPE 2 PROTECTIVE RESPONSE. T FOLLICULAR HELPER (TFH) CELLS ARE AN IMPORTANT COMPONENT OF GERMINAL CENTER (GC)-MEDIATED HUMORAL IMMUNITY. YET, HOW A CHRONIC TYPE 1 VERSUS PROTECTIVE TYPE 2 HELMINTH INFECTION MODULATES TFH-GC RESPONSES REMAINS POORLY UNDERSTOOD. HERE, WE EMPLOY THE HELMINTH TRICHURIS MURIS MODEL AND DEMONSTRATE THAT TFH CELL PHENOTYPES AND GC ARE DIFFERENTIALLY REGULATED IN ACUTE VERSUS CHRONIC INFECTION. THE LATTER FAILED TO INDUCE TFH-GC B CELL RESPONSES, WITH TFH CELLS EXPRESSING TAU-BET AND INTERFERON-GAMMA. IN CONTRAST, INTERLEUKIN-4-PRODUCING TFH CELLS DOMINATE RESPONSES TO AN ACUTE, RESOLVING INFECTION. HEIGHTENED EXPRESSION AND INCREASED CHROMATIN ACCESSIBILITY OF T HELPER (TH)1- AND TH2 CELL-ASSOCIATED GENES ARE OBSERVED IN CHRONIC AND ACUTE INDUCED TFH CELLS, RESPECTIVELY. BLOCKADE OF THE TH1 CELL RESPONSE BY T-CELL-INTRINSIC T-BET DELETION PROMOTED TFH CELL EXPANSION DURING CHRONIC INFECTION, POINTING TO A CORRELATION BETWEEN A ROBUST TFH CELL RESPONSE AND PROTECTIVE IMMUNITY TO PARASITES. FINALLY, BLOCKADE OF TFH-GC INTERACTIONS IMPAIRED TYPE 2 IMMUNITY, REVEALING THE CRITICAL PROTECTIVE ROLE OF GC-DEPENDENT TH2-LIKE TFH CELL RESPONSES DURING ACUTE INFECTION. COLLECTIVELY, THESE RESULTS PROVIDE NEW INSIGHTS INTO THE PROTECTIVE ROLES OF TFH-GC RESPONSES AND IDENTIFY DISTINCT TRANSCRIPTIONAL AND EPIGENETIC FEATURES OF TFH CELLS THAT EMERGE DURING RESOLVING OR CHRONIC T. MURIS INFECTION. 2023 2 987 35 CHRONIC SCHISTOSOMIASIS DURING PREGNANCY EPIGENETICALLY REPROGRAMS T-CELL DIFFERENTIATION IN OFFSPRING OF INFECTED MOTHERS. SCHISTOSOMIASIS IS A NONTRANSPLACENTAL HELMINTH INFECTION. CHRONIC INFECTION DURING PREGNANCY SUPPRESSES ALLERGIC AIRWAY RESPONSES IN OFFSPRING. WE ADDRESSED THE QUESTION WHETHER IN UTERO EXPOSURE TO CHRONIC SCHISTOSOME INFECTION (REG PHASE) IN MICE AFFECTS B-CELL AND T-CELL DEVELOPMENT. THEREFORE, WE FOCUSED OUR ANALYSES ON T-CELL DIFFERENTIATION CAPACITY INDUCED BY EPIGENETIC CHANGES IN PROMOTER REGIONS OF SIGNATURE CYTOKINES IN OFFSPRING. HERE, WE SHOW THAT NAIVE T CELLS FROM OFFSPRING OF SCHISTOSOME INFECTED FEMALE MICE HAD A STRONG CAPACITY TO DIFFERENTIATE INTO T(H) 1 CELLS, WHEREAS T(H) 2 DIFFERENTIATION WAS IMPAIRED. IN ACCORDANCE, REDUCED LEVELS OF HISTONE ACETYLATION OF THE IL-4 PROMOTER REGIONS WERE OBSERVED IN NAIVE T CELLS. TO CONCLUDE, OUR MOUSE MODEL REVEALED DISTINCT EPIGENETIC CHANGES WITHIN THE NAIVE T-CELL COMPARTMENT AFFECTING T(H) 2 AND T(H) 1 CELL DIFFERENTIATION IN OFFSPRING OF MOTHERS WITH CHRONIC HELMINTH INFECTION. THESE FINDINGS COULD EVENTUALLY HELP UNDERSTAND HOW HELMINTHS ALTER T-CELL DRIVEN IMMUNE RESPONSES INDUCED BY ALLERGENS, BACTERIAL OR VIRAL INFECTIONS, AS WELL AS VACCINES. 2017 3 2819 22 FILARIAL AND WOLBACHIA GENOMICS. FILARIAL NEMATODE PARASITES, THE CAUSATIVE AGENTS FOR A SPECTRUM OF ACUTE AND CHRONIC DISEASES INCLUDING LYMPHATIC FILARIASIS AND RIVER BLINDNESS, THREATEN THE WELL-BEING AND LIVELIHOOD OF HUNDREDS OF MILLIONS OF PEOPLE IN THE DEVELOPING REGIONS OF THE WORLD. THE 2007 PUBLICATION ON A DRAFT ASSEMBLY OF THE 95-MB GENOME OF THE HUMAN FILARIAL PARASITE BRUGIA MALAYI- REPRESENTING THE FIRST HELMINTH PARASITE GENOME TO BE SEQUENCED - HAS BEEN FOLLOWED IN RAPID SUCCESSION BY PROJECTS THAT HAVE RESULTED IN THE GENOME SEQUENCING OF SIX ADDITIONAL FILARIAL SPECIES, SEVEN NONFILARIAL NEMATODE PARASITES OF ANIMALS AND NEARLY 30 PLANT PARASITIC AND FREE-LIVING SPECIES. PARALLEL TO THE GENOMIC SEQUENCING, TRANSCRIPTOMIC AND PROTEOMIC PROJECTS HAVE FACILITATED GENOME ANNOTATION, EXPANDED OUR UNDERSTANDING OF STAGE-ASSOCIATED GENE EXPRESSION AND PROVIDED A FIRST LOOK AT THE ROLE OF EPIGENETIC REGULATION OF FILARIAL GENOMES THROUGH MICRORNAS. THE EXPANSION IN FILARIAL GENOMICS WILL ALSO PROVIDE A SIGNIFICANT ENRICHMENT IN OUR KNOWLEDGE OF THE DIVERSITY AND VARIABILITY IN THE GENOMES OF THE ENDOSYMBIOTIC BACTERIUM WOLBACHIA LEADING TO A BETTER UNDERSTANDING OF THE GENETIC PRINCIPLES THAT GOVERN FILARIAL-WOLBACHIA MUTUALISM. THE GOAL HERE IS TO PROVIDE AN OVERVIEW OF THE TRENDS AND ADVANCES IN FILARIAL AND WOLBACHIA GENOMICS. 2012 4 5996 34 TH2 CELLS IN HEALTH AND DISEASE. HELPER T (TH) CELL SUBSETS DIRECT IMMUNE RESPONSES BY PRODUCING SIGNATURE CYTOKINES. TH2 CELLS PRODUCE IL-4, IL-5, AND IL-13, WHICH ARE IMPORTANT IN HUMORAL IMMUNITY AND PROTECTION FROM HELMINTH INFECTION AND ARE CENTRAL TO THE PATHOGENESIS OF MANY ALLERGIC INFLAMMATORY DISEASES. MOLECULAR ANALYSIS OF TH2 CELL DIFFERENTIATION AND MAINTENANCE OF FUNCTION HAS LED TO RECENT DISCOVERIES THAT HAVE REFINED OUR UNDERSTANDING OF TH2 CELL BIOLOGY. EPIGENETIC REGULATION OF GATA3 EXPRESSION BY CHROMATIN REMODELING COMPLEXES SUCH AS POLYCOMB AND TRITHORAX IS CRUCIAL FOR MAINTAINING TH2 CELL IDENTITY. IN THE CONTEXT OF ALLERGIC DISEASES, MEMORY-TYPE PATHOGENIC TH2 CELLS HAVE BEEN IDENTIFIED IN BOTH MICE AND HUMANS. TO BETTER UNDERSTAND THESE DISEASE-DRIVING CELL POPULATIONS, WE HAVE DEVELOPED A MODEL CALLED THE PATHOGENIC TH POPULATION DISEASE INDUCTION MODEL. THE CONCEPT OF DEFINED SUBSETS OF PATHOGENIC TH CELLS MAY SPUR NEW, EFFECTIVE STRATEGIES FOR TREATING INTRACTABLE CHRONIC INFLAMMATORY DISORDERS. 2017 5 568 36 BATF REGULATES PROGENITOR TO CYTOLYTIC EFFECTOR CD8(+) T CELL TRANSITION DURING CHRONIC VIRAL INFECTION. DURING CHRONIC VIRAL INFECTION, CD8(+) T CELLS DEVELOP INTO THREE MAJOR PHENOTYPICALLY AND FUNCTIONALLY DISTINCT SUBSETS: LY108(+)TCF-1(+) PROGENITORS, LY108(-)CX(3)CR1(-) TERMINALLY EXHAUSTED CELLS AND THE RECENTLY IDENTIFIED CX(3)CR1(+) CYTOTOXIC EFFECTOR CELLS. NEVERTHELESS, HOW CX(3)CR1(+) EFFECTOR CELL DIFFERENTIATION IS TRANSCRIPTIONALLY AND EPIGENETICALLY REGULATED REMAINS ELUSIVE. HERE, WE IDENTIFY DISTINCT GENE REGULATORY NETWORKS AND EPIGENETIC LANDSCAPES UNDERPINNING THE FORMATION OF THESE SUBSETS. NOTABLY, OUR DATA DEMONSTRATE THAT CX(3)CR1(+) EFFECTOR CELLS BEAR A STRIKING SIMILARITY TO SHORT-LIVED EFFECTOR CELLS DURING ACUTE INFECTION. GENETIC DELETION OF TBX21 SIGNIFICANTLY DIMINISHED FORMATION OF THE CX(3)CR1(+) SUBSET. IMPORTANTLY, WE FURTHER IDENTIFY A PREVIOUSLY UNAPPRECIATED ROLE FOR THE TRANSCRIPTION FACTOR BATF IN MAINTAINING A PERMISSIVE CHROMATIN STRUCTURE THAT ALLOWS THE TRANSITION FROM TCF-1(+) PROGENITORS TO CX(3)CR1(+) EFFECTOR CELLS. BATF DIRECTLY BOUND TO REGULATORY REGIONS NEAR TBX21 AND KLF2, MODULATING THEIR ENHANCER ACCESSIBILITY TO FACILITATE THE TRANSITION. THESE MECHANISTIC INSIGHTS CAN POTENTIALLY BE HARNESSED TO OVERCOME T CELL EXHAUSTION DURING CHRONIC INFECTION AND CANCER. 2021 6 4057 34 MAPPING THE LINEAGE RELATIONSHIP BETWEEN CXCR5(+) AND CXCR5(-) CD4(+) T CELLS IN HIV-INFECTED HUMAN LYMPH NODES. CXCR5 IS A KEY MARKER OF FOLLICULAR HELPER T (T(FH)) CELLS. USING PRIMARY LYMPH NODES (LNS) FROM HIV-INFECTED PATIENTS, WE IDENTIFIED A POPULATION OF CXCR5(-) CD4(+) T CELLS WITH T(FH)-CELL-LIKE FEATURES. THIS CXCR5(-) SUBSET BECOMES EXPANDED IN SEVERE HIV INFECTION AND IS CHARACTERIZED BY THE UPREGULATION OF ACTIVATION MARKERS AND HIGH PD-1 AND ICOS SURFACE EXPRESSION. INTEGRATED ANALYSES ON THE PHENOTYPIC HETEROGENEITY, FUNCTIONAL CAPACITY, T CELL RECEPTOR (TCR) REPERTOIRE, TRANSCRIPTIONAL PROFILE, AND EPIGENETIC STATE OF CXCR5(-)PD-1(+)ICOS(+) T CELLS REVEALED A SHARED CLONAL RELATIONSHIP WITH T(FH) CELLS. CXCR5(-)PD-1(+)ICOS(+) T CELLS RETAINED A POISED STATE FOR CXCR5 EXPRESSION AND EXHIBITED A MIGRATORY TRANSCRIPTIONAL PROGRAM. TCR SEQUENCE OVERLAP REVEALED A CONTRIBUTION OF LN-DERIVED CXCR5(-)PD-1(+)ICOS(+) T CELLS TO CIRCULATING CXCR5(-) CD4(+) T CELLS WITH B CELL HELP FUNCTION. THESE DATA LINK LN PATHOLOGY TO CIRCULATING T CELLS AND EXPAND THE CURRENT UNDERSTANDING ON THE DIVERSITY OF T CELLS THAT REGULATE B CELL RESPONSES DURING CHRONIC INFLAMMATION. 2019 7 2443 22 EPIGENETIC STABILITY OF EXHAUSTED T CELLS LIMITS DURABILITY OF REINVIGORATION BY PD-1 BLOCKADE. BLOCKING PROGRAMMED DEATH-1 (PD-1) CAN REINVIGORATE EXHAUSTED CD8 T CELLS (T(EX)) AND IMPROVE CONTROL OF CHRONIC INFECTIONS AND CANCER. HOWEVER, WHETHER BLOCKING PD-1 CAN REPROGRAM T(EX) INTO DURABLE MEMORY T CELLS (T(MEM)) IS UNCLEAR. WE FOUND THAT REINVIGORATION OF T(EX) IN MICE BY PD-L1 BLOCKADE CAUSED MINIMAL MEMORY DEVELOPMENT. AFTER BLOCKADE, REINVIGORATED T(EX) BECAME REEXHAUSTED IF ANTIGEN CONCENTRATION REMAINED HIGH AND FAILED TO BECOME T(MEM) UPON ANTIGEN CLEARANCE. T(EX) ACQUIRED AN EPIGENETIC PROFILE DISTINCT FROM THAT OF EFFECTOR T CELLS (T(EFF)) AND T(MEM) CELLS THAT WAS MINIMALLY REMODELED AFTER PD-L1 BLOCKADE. THIS FINDING SUGGESTS THAT T(EX) ARE A DISTINCT LINEAGE OF CD8 T CELLS. NEVERTHELESS, PD-1 PATHWAY BLOCKADE RESULTED IN TRANSCRIPTIONAL REWIRING AND REENGAGEMENT OF EFFECTOR CIRCUITRY IN THE T(EX) EPIGENETIC LANDSCAPE. THESE DATA INDICATE THAT EPIGENETIC FATE INFLEXIBILITY MAY LIMIT CURRENT IMMUNOTHERAPIES. 2016 8 5853 29 SUBSETS OF EXHAUSTED CD8(+) T CELLS DIFFERENTIALLY MEDIATE TUMOR CONTROL AND RESPOND TO CHECKPOINT BLOCKADE. T CELL DYSFUNCTION IS A HALLMARK OF MANY CANCERS, BUT THE BASIS FOR T CELL DYSFUNCTION AND THE MECHANISMS BY WHICH ANTIBODY BLOCKADE OF THE INHIBITORY RECEPTOR PD-1 (ANTI-PD-1) REINVIGORATES T CELLS ARE NOT FULLY UNDERSTOOD. HERE WE SHOW THAT SUCH THERAPY ACTS ON A SPECIFIC SUBPOPULATION OF EXHAUSTED CD8(+) TUMOR-INFILTRATING LYMPHOCYTES (TILS). DYSFUNCTIONAL CD8(+) TILS POSSESS CANONICAL EPIGENETIC AND TRANSCRIPTIONAL FEATURES OF EXHAUSTION THAT MIRROR THOSE SEEN IN CHRONIC VIRAL INFECTION. EXHAUSTED CD8(+) TILS INCLUDE A SUBPOPULATION OF 'PROGENITOR EXHAUSTED' CELLS THAT RETAIN POLYFUNCTIONALITY, PERSIST LONG TERM AND DIFFERENTIATE INTO 'TERMINALLY EXHAUSTED' TILS. CONSEQUENTLY, PROGENITOR EXHAUSTED CD8(+) TILS ARE BETTER ABLE TO CONTROL TUMOR GROWTH THAN ARE TERMINALLY EXHAUSTED T CELLS. PROGENITOR EXHAUSTED TILS CAN RESPOND TO ANTI-PD-1 THERAPY, BUT TERMINALLY EXHAUSTED TILS CANNOT. PATIENTS WITH MELANOMA WHO HAVE A HIGHER PERCENTAGE OF PROGENITOR EXHAUSTED CELLS EXPERIENCE A LONGER DURATION OF RESPONSE TO CHECKPOINT-BLOCKADE THERAPY. THUS, APPROACHES TO EXPAND THE POPULATION OF PROGENITOR EXHAUSTED CD8(+) T CELLS MIGHT BE AN IMPORTANT COMPONENT OF IMPROVING THE RESPONSE TO CHECKPOINT BLOCKADE. 2019 9 6482 32 TOX TRANSCRIPTIONALLY AND EPIGENETICALLY PROGRAMS CD8(+) T CELL EXHAUSTION. EXHAUSTED CD8(+) T (T(EX)) CELLS IN CHRONIC INFECTIONS AND CANCER HAVE LIMITED EFFECTOR FUNCTION, HIGH CO-EXPRESSION OF INHIBITORY RECEPTORS AND EXTENSIVE TRANSCRIPTIONAL CHANGES COMPARED WITH EFFECTOR (T(EFF)) OR MEMORY (T(MEM)) CD8(+) T CELLS. T(EX) CELLS ARE IMPORTANT CLINICAL TARGETS OF CHECKPOINT BLOCKADE AND OTHER IMMUNOTHERAPIES. EPIGENETICALLY, T(EX) CELLS ARE A DISTINCT IMMUNE SUBSET, WITH A UNIQUE CHROMATIN LANDSCAPE COMPARED WITH T(EFF) AND T(MEM) CELLS. HOWEVER, THE MECHANISMS THAT GOVERN THE TRANSCRIPTIONAL AND EPIGENETIC DEVELOPMENT OF T(EX) CELLS REMAIN UNKNOWN. HERE WE IDENTIFY THE HMG-BOX TRANSCRIPTION FACTOR TOX AS A CENTRAL REGULATOR OF T(EX) CELLS IN MICE. TOX IS LARGELY DISPENSABLE FOR THE FORMATION OF T(EFF) AND T(MEM) CELLS, BUT IT IS CRITICAL FOR EXHAUSTION: IN THE ABSENCE OF TOX, T(EX) CELLS DO NOT FORM. TOX IS INDUCED BY CALCINEURIN AND NFAT2, AND OPERATES IN A FEED-FORWARD LOOP IN WHICH IT BECOMES CALCINEURIN-INDEPENDENT AND SUSTAINED IN T(EX) CELLS. ROBUST EXPRESSION OF TOX THEREFORE RESULTS IN COMMITMENT TO T(EX) CELLS BY TRANSLATING PERSISTENT STIMULATION INTO A DISTINCT T(EX) CELL TRANSCRIPTIONAL AND EPIGENETIC DEVELOPMENTAL PROGRAM. 2019 10 1262 28 CUTTING EDGE: PROLONGED EXPOSURE TO HIV REINFORCES A POISED EPIGENETIC PROGRAM FOR PD-1 EXPRESSION IN VIRUS-SPECIFIC CD8 T CELLS. AG-SPECIFIC CD8 T CELLS PLAY A CRITICAL ROLE IN CONTROLLING HIV INFECTION BUT EVENTUALLY LOSE ANTIVIRAL FUNCTIONS IN PART BECAUSE OF EXPRESSION AND SIGNALING THROUGH THE INHIBITORY PROGRAMMED DEATH-1 (PD-1) RECEPTOR. TO BETTER UNDERSTAND THE IMPACT OF PROLONGED TCR LIGATION ON REGULATION OF PD-1 EXPRESSION IN HIV-SPECIFIC CD8 T CELLS, WE INVESTIGATED THE CAPACITY OF VIRUS-SPECIFIC CD8 T CELLS TO MODIFY THE PD-1 EPIGENETIC PROGRAM AFTER REDUCTION IN VIRAL LOAD. WE OBSERVED THAT THE TRANSCRIPTIONAL REGULATORY REGION WAS UNMETHYLATED IN THE PD-1(HI) HIV-SPECIFIC CD8 T CELLS, WHEREAS IT REMAINED METHYLATED IN DONOR-MATCHED NAIVE CELLS AT ACUTE AND CHRONIC STAGES OF INFECTION. SURPRISINGLY, THE PD-1 PROMOTER REMAINED UNMETHYLATED IN HIV-SPECIFIC CD8 T CELLS FROM SUBJECTS WITH A VIRAL LOAD CONTROLLED BY ANTIVIRAL THERAPY FOR >2 Y OR FROM ELITE CONTROLLERS. TOGETHER, THESE DATA DEMONSTRATE THAT THE EPIGENETIC PROGRAM AT THE PD-1 LOCUS BECOMES FIXED AFTER PROLONGED EXPOSURE TO HIV VIRUS. 2013 11 3945 41 LNCRNA IL21-AS1 INTERACTS WITH HNRNPU PROTEIN TO PROMOTE IL21 OVEREXPRESSION AND ABERRANT DIFFERENTIATION OF TFH CELLS IN SYSTEMIC LUPUS ERYTHEMATOSUS. BACKGROUND: THE ABERRANT DIFFERENTIATION OF T FOLLICULAR HELPER (TFH) CELLS PLAYS AN IMPORTANT ROLE IN THE PATHOGENESIS OF SYSTEMIC LUPUS ERYTHEMATOSUS (SLE). HOWEVER, THE MECHANISM OF REGULATING TFH CELLS DIFFERENTIATION REMAINS UNCLEAR. LONG NONCODING RNAS (LNCRNAS) ACT AS IMPORTANT REGULATORS IN THE PROCESSES OF INNATE AND ADAPTIVE IMMUNE RESPONSE. WHETHER LNCRNAS ARE INVOLVED IN REGULATING TFH CELL DIFFERENTIATION AND AUTOIMMUNE RESPONSES NEED TO BE FURTHER IDENTIFIED. METHODS: THE CHARACTERS AND FUNCTIONS OF HUMAN IL21-AS1 AND ITS MOUSE HOMOLOGOUS LNCRNA (MIL21-AS) WERE INVESTIGATED BY A SERIES OF BIOCHEMICAL ASSAYS AND CELL TRANSFECTION ASSAY. MIL21-AS1 REGULATING HUMORAL IMMUNE RESPONSE IN VIVO WAS EXPLORED BY KEYHOLE LIMPET HAEMOCYANIN (KLH) AND CHRONIC GRAFT VERSUS HOST DISEASE (CGVHD) MODEL. RESULTS: HUMAN IL21-AS1 AND ITS MOUSE HOMOLOGOUS LNCRNA (MIL21-AS) WERE IDENTIFIED AND CLONED. WE UNCOVERED THAT IL21-AS1 WAS HIGHLY EXPRESSED IN CD4(+) T CELLS OF SLE PATIENTS AND TFH CELLS, WHICH PROMOTED DIFFERENTIATION OF TFH CELLS. MECHANISTICALLY, IL21-AS1 BOUND HETEROGENEOUS NUCLEAR RIBONUCLEOPROTEIN U AND RECRUITED ACETYLTRANSFERASES CREB-BINDING PROTEIN TO THE PROMOTER OF IL21, LEADING TO THE TRANSCRIPTIONAL ACTIVATION OF IL21 AND TFH CELLS DIFFERENTIATION THROUGH INCREASING HISTONE H3 ACETYLATION LEVEL ON IL21 PROMOTER. MOREOVER, TFH PROPORTION AND ANTIBODIES PRODUCTION WERE SIGNIFICANTLY INCREASED IN MIL21-AS KNOCK-IN MICE IMMUNIZED WITH KLH. MIL21-AS1 OVEREXPRESSION ALSO EXACERBATED THE LUPUS-LIKE PHENOTYPE IN CGVHD MICE MODEL. CONCLUSIONS: OUR RESULTS DEMONSTRATE THAT IL21-AS1 ACTIVATES IL21 TRANSCRIPTION VIA EPIGENETIC MECHANISM TO PROMOTE GERMINAL CENTRE RESPONSE, ADDING INSIGHT INTO THE MOLECULAR REGULATION OF AUTOIMMUNE PATHOGENESIS AND PROVIDING A NOVEL TARGET FOR SLE TREATMENT. 2022 12 2421 34 EPIGENETIC SIGNATURE OF PD-1+ TCF1+ CD8 T CELLS THAT ACT AS RESOURCE CELLS DURING CHRONIC VIRAL INFECTION AND RESPOND TO PD-1 BLOCKADE. WE HAVE RECENTLY DEFINED A NOVEL POPULATION OF PD-1 (PROGRAMMED CELL DEATH 1)+ TCF1 (T CELL FACTOR 1)+ VIRUS-SPECIFIC CD8 T CELLS THAT FUNCTION AS RESOURCE CELLS DURING CHRONIC LCMV INFECTION AND PROVIDE THE PROLIFERATIVE BURST SEEN AFTER PD-1 BLOCKADE. SUCH CD8 T CELLS HAVE BEEN FOUND IN OTHER CHRONIC INFECTIONS AND ALSO IN CANCER IN MICE AND HUMANS. THESE CD8 T CELLS EXHIBIT STEM-LIKE PROPERTIES UNDERGOING SELF-RENEWAL AND ALSO DIFFERENTIATING INTO THE TERMINALLY EXHAUSTED CD8 T CELLS. HERE WE COMPARED THE EPIGENETIC SIGNATURE OF STEM-LIKE CD8 T CELLS WITH EXHAUSTED CD8 T CELLS. ATAC-SEQ ANALYSIS SHOWED THAT STEM-LIKE CD8 T CELLS HAD A UNIQUE SIGNATURE IMPLICATING ACTIVITY OF HMG (TCF) AND RHD (NF-KAPPAB) TRANSCRIPTION FACTOR FAMILY MEMBERS IN CONTRAST TO HIGHER ACCESSIBILITY TO ETS AND RUNX MOTIFS IN EXHAUSTED CD8 T CELLS. IN ADDITION, REGULATORY REGIONS OF THE TRANSCRIPTION FACTORS TCF7 AND ID3 WERE MORE ACCESSIBLE IN STEM-LIKE CELLS WHEREAS PRDM1 AND ID2 WERE MORE ACCESSIBLE IN EXHAUSTED CD8 T CELLS. WE ALSO COMPARED THE EPIGENETIC SIGNATURES OF THE 2 CD8 T CELL SUBSETS FROM CHRONICALLY INFECTED MICE WITH EFFECTOR AND MEMORY CD8 T CELLS GENERATED AFTER AN ACUTE LCMV INFECTION. BOTH CD8 T CELL SUBSETS GENERATED DURING CHRONIC INFECTION WERE STRIKINGLY DIFFERENT FROM CD8 T CELL SUBSETS FROM ACUTE INFECTION. INTERESTINGLY, THE STEM-LIKE CD8 T CELL SUBSET FROM CHRONIC INFECTION, DESPITE SHARING KEY FUNCTIONAL PROPERTIES WITH MEMORY CD8 T CELLS, HAD A VERY DISTINCT EPIGENETIC PROGRAM. THESE RESULTS SHOW THAT THE CHRONIC STEM-LIKE CD8 T CELL PROGRAM REPRESENTS A SPECIFIC ADAPTATION OF THE T CELL RESPONSE TO PERSISTENT ANTIGENIC STIMULATION. 2019 13 6578 28 TREATMENT WITH TRICHURIS SUIS SOLUBLE PRODUCTS DURING MONOCYTE-TO-MACROPHAGE DIFFERENTIATION REDUCES INFLAMMATORY RESPONSES THROUGH EPIGENETIC REMODELING. HELMINTHS HAVE STRONG IMMUNOREGULATORY PROPERTIES THAT MAY BE EXPLOITED IN TREATMENT OF CHRONIC IMMUNE DISORDERS, SUCH AS MULTIPLE SCLEROSIS AND INFLAMMATORY BOWEL DISEASE. ESSENTIAL PLAYERS IN THE PATHOGENESIS OF THESE DISEASES ARE PROINFLAMMATORY MACROPHAGES. WE PRESENT EVIDENCE THAT HELMINTHS MODULATE THE FUNCTION AND PHENOTYPE OF THESE INNATE IMMUNE CELLS. WE FOUND THAT SOLUBLE PRODUCTS DERIVED FROM THE TRICHURIS SUIS (TSSP) SIGNIFICANTLY AFFECT THE DIFFERENTIATION OF MONOCYTES INTO MACROPHAGES AND THEIR SUBSEQUENT POLARIZATION. TSSPS REDUCE THE EXPRESSION AND PRODUCTION OF INFLAMMATORY CYTOKINES, INCLUDING IL-6 AND TNF, IN HUMAN PROINFLAMMATORY M1 MACROPHAGES. TSSPS INDUCE A CONCOMITANT ANTI-INFLAMMATORY M2 SIGNATURE, WITH INCREASED IL-10 PRODUCTION. FURTHERMORE, THEY SUPPRESS CHIT ACTIVITY AND ENHANCE SECRETION OF MATRIX METALLOPROTEINASE 9. SHORT-TERM TRIGGERING OF MONOCYTES WITH TSSPS EARLY DURING MONOCYTE-TO-MACROPHAGE DIFFERENTIATION IMPRINTED THESE PHENOTYPIC ALTERATIONS, SUGGESTING LONG-LASTING EPIGENETIC CHANGES. THE TSSP-INDUCED EFFECTS IN M1 MACROPHAGES WERE COMPLETELY REVERSED BY INHIBITING HISTONE DEACETYLASES, WHICH CORRESPONDED WITH DECREASED HISTONE ACETYLATION AT THE TNF AND IL6 PROMOTERS. THESE RESULTS DEMONSTRATE THAT TSSPS HAVE A POTENT AND SUSTAINED IMMUNOMODULATORY EFFECT ON HUMAN MACROPHAGE DIFFERENTIATION AND POLARIZATION THROUGH EPIGENETIC REMODELING AND PROVIDE NEW INSIGHTS INTO THE MECHANISMS BY WHICH HELMINTHS MODULATE HUMAN IMMUNE RESPONSES.-HOEKSEMA, M. A., LAAN, L. C., POSTMA, J. J., CUMMINGS, R. D., DE WINTHER, M. P. J., DIJKSTRA, C. D., VAN DIE, I., KOOIJ, G. TREATMENT WITH TRICHURIS SUIS SOLUBLE PRODUCTS DURING MONOCYTE-TO-MACROPHAGE DIFFERENTIATION REDUCES INFLAMMATORY RESPONSES THROUGH EPIGENETIC REMODELING. 2016 14 6055 31 THE CXXC1 SUBUNIT OF THE TRITHORAX COMPLEX DIRECTS EPIGENETIC LICENSING OF CD4+ T CELL DIFFERENTIATION. DIFFERENT DYNAMICS OF GENE EXPRESSION ARE OBSERVED DURING CELL DIFFERENTIATION. IN T CELLS, GENES THAT ARE TURNED ON EARLY OR TURNED OFF AND STAY OFF HAVE BEEN THOROUGHLY STUDIED. HOWEVER, GENES THAT ARE INITIALLY TURNED OFF BUT THEN TURNED ON AGAIN AFTER STIMULATION HAS CEASED HAVE NOT BEEN DEFINED; THEY ARE OBVIOUSLY IMPORTANT, ESPECIALLY IN THE CONTEXT OF ACUTE VERSUS CHRONIC INFLAMMATION. USING THE TH1/TH2 DIFFERENTIATION PARADIGM, WE FOUND THAT THE CXXC1 SUBUNIT OF THE TRITHORAX COMPLEX DIRECTS TRANSCRIPTION OF GENES INITIALLY DOWN-REGULATED BY TCR STIMULATION BUT UP-REGULATED AGAIN IN A LATER PHASE. THE LATE UP-REGULATION OF THESE GENES WAS IMPAIRED EITHER BY PROLONGED TCR STIMULATION OR CXXC1 DEFICIENCY, WHICH LED TO DECREASED EXPRESSION OF TRIB3 AND KLF2 IN TH1 AND TH2 CELLS, RESPECTIVELY. LOSS OF CXXC1 RESULTED IN ENHANCED PATHOGENICITY IN ALLERGIC AIRWAY INFLAMMATION IN VIVO. THUS, CXXC1 PLAYS ESSENTIAL ROLES IN THE ESTABLISHMENT OF A PROPER CD4+ T CELL IMMUNE SYSTEM VIA EPIGENETIC CONTROL OF A SPECIFIC SET OF GENES. 2021 15 559 25 BACH2 ENFORCES THE TRANSCRIPTIONAL AND EPIGENETIC PROGRAMS OF STEM-LIKE CD8(+) T CELLS. DURING CHRONIC INFECTION AND CANCER, A SELF-RENEWING CD8(+) T CELL SUBSET MAINTAINS LONG-TERM IMMUNITY AND IS CRITICAL TO THE EFFECTIVENESS OF IMMUNOTHERAPY. THESE STEM-LIKE CD8(+) T CELLS DIVERGE FROM OTHER CD8(+) SUBSETS EARLY AFTER CHRONIC VIRAL INFECTION. HOWEVER, PATHWAYS GUARDING STEM-LIKE CD8(+) T CELLS AGAINST TERMINAL EXHAUSTION REMAIN UNCLEAR. HERE, WE SHOW THAT THE GENE ENCODING TRANSCRIPTIONAL REPRESSOR BACH2 IS TRANSCRIPTIONALLY AND EPIGENETICALLY ACTIVE IN STEM-LIKE CD8(+) T CELLS BUT NOT TERMINALLY EXHAUSTED CELLS EARLY AFTER INFECTION. BACH2 OVEREXPRESSION ENFORCED STEM-LIKE CELL FATE, WHEREAS BACH2 DEFICIENCY IMPAIRED STEM-LIKE CD8(+) T CELL DIFFERENTIATION. SINGLE-CELL TRANSCRIPTOMIC AND EPIGENOMIC APPROACHES REVEALED THAT BACH2 ESTABLISHED THE TRANSCRIPTIONAL AND EPIGENETIC PROGRAMS OF STEM-LIKE CD8(+) T CELLS. IN ADDITION, BACH2 SUPPRESSED THE MOLECULAR PROGRAM DRIVING TERMINAL EXHAUSTION THROUGH TRANSCRIPTIONAL REPRESSION AND EPIGENETIC SILENCING. THUS, OUR STUDY REVEALS A NEW PATHWAY THAT ENFORCES COMMITMENT TO STEM-LIKE CD8(+) LINEAGE AND PREVENTS AN ALTERNATIVE TERMINALLY EXHAUSTED CELL FATE. 2021 16 6481 29 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 17 6121 28 THE EPIGENETIC LANDSCAPE OF T CELL EXHAUSTION. EXHAUSTED T CELLS IN CANCER AND CHRONIC VIRAL INFECTION EXPRESS DISTINCTIVE PATTERNS OF GENES, INCLUDING SUSTAINED EXPRESSION OF PROGRAMMED CELL DEATH PROTEIN 1 (PD-1). HOWEVER, THE REGULATION OF GENE EXPRESSION IN EXHAUSTED T CELLS IS POORLY UNDERSTOOD. HERE, WE DEFINE THE ACCESSIBLE CHROMATIN LANDSCAPE IN EXHAUSTED CD8(+) T CELLS AND SHOW THAT IT IS DISTINCT FROM FUNCTIONAL MEMORY CD8(+) T CELLS. EXHAUSTED CD8(+) T CELLS IN HUMANS AND A MOUSE MODEL OF CHRONIC VIRAL INFECTION ACQUIRE A STATE-SPECIFIC EPIGENETIC LANDSCAPE ORGANIZED INTO FUNCTIONAL MODULES OF ENHANCERS. GENOME EDITING SHOWS THAT PD-1 EXPRESSION IS REGULATED IN PART BY AN EXHAUSTION-SPECIFIC ENHANCER THAT CONTAINS ESSENTIAL RAR, T-BET, AND SOX3 MOTIFS. FUNCTIONAL ENHANCER MAPS MAY OFFER TARGETS FOR GENOME EDITING THAT ALTER GENE EXPRESSION PREFERENTIALLY IN EXHAUSTED CD8(+) T CELLS. 2016 18 1379 26 DEVELOPMENTAL RELATIONSHIPS OF FOUR EXHAUSTED CD8(+) T CELL SUBSETS REVEALS UNDERLYING TRANSCRIPTIONAL AND EPIGENETIC LANDSCAPE CONTROL MECHANISMS. CD8(+) T CELL EXHAUSTION IS A MAJOR BARRIER TO CURRENT ANTI-CANCER IMMUNOTHERAPIES. DESPITE THIS, THE DEVELOPMENTAL BIOLOGY OF EXHAUSTED CD8(+) T CELLS (TEX) REMAINS POORLY DEFINED, RESTRAINING IMPROVEMENT OF STRATEGIES AIMED AT "RE-INVIGORATING" TEX CELLS. HERE, WE DEFINED A FOUR-CELL-STAGE DEVELOPMENTAL FRAMEWORK FOR TEX CELLS. TWO TCF1(+) PROGENITOR SUBSETS WERE IDENTIFIED, ONE TISSUE RESTRICTED AND QUIESCENT AND ONE MORE BLOOD ACCESSIBLE, THAT GRADUALLY LOST TCF1 AS IT DIVIDED AND CONVERTED TO A THIRD INTERMEDIATE TEX SUBSET. THIS INTERMEDIATE SUBSET RE-ENGAGED SOME EFFECTOR BIOLOGY AND INCREASED UPON PD-L1 BLOCKADE BUT ULTIMATELY CONVERTED INTO A FOURTH, TERMINALLY EXHAUSTED SUBSET. BY USING TRANSCRIPTIONAL AND EPIGENETIC ANALYSES, WE IDENTIFIED THE CONTROL MECHANISMS UNDERLYING SUBSET TRANSITIONS AND DEFINED A KEY INTERPLAY BETWEEN TCF1, T-BET, AND TOX IN THE PROCESS. THESE DATA REVEAL A FOUR-STAGE DEVELOPMENTAL HIERARCHY FOR TEX CELLS AND DEFINE THE MOLECULAR, TRANSCRIPTIONAL, AND EPIGENETIC MECHANISMS THAT COULD PROVIDE OPPORTUNITIES TO IMPROVE CANCER IMMUNOTHERAPY. 2020 19 1763 39 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 20 198 29 ACQUIRED TRANSCRIPTIONAL PROGRAMMING IN FUNCTIONAL AND EXHAUSTED VIRUS-SPECIFIC CD8 T CELLS. PURPOSE OF REVIEW: FAILURE TO CONTROL VIRAL INFECTIONS SUCH AS HIV RESULTS IN T-CELL RECEPTOR (TCR) AND INHIBITORY RECEPTOR DRIVEN EXHAUSTION OF ANTIGEN-SPECIFIC T CELLS. PERSISTENT SIGNALING BY THESE RECEPTORS DURING CHRONIC VIRAL INFECTION SCULPTS THE TRANSCRIPTIONAL REGULATORY PROGRAMS OF VIRUS-SPECIFIC T CELLS. THE RESULTING GENE EXPRESSION PROFILE IS TAILORED TO TEMPER THE POTENTIALLY DAMAGING EFFECTOR FUNCTIONS OF CYTOTOXIC T CELLS AND ADAPT THEM TO AN ANTIGEN-RICH AND INFLAMMATION-RICH ENVIRONMENT. HERE WE REVIEW RECENT STUDIES INVESTIGATING MECHANISMS OF TRANSCRIPTIONAL REGULATION OF EFFECTOR, FUNCTIONAL MEMORY, AND EXHAUSTED T-CELL FUNCTIONS DURING ACUTE VERSUS CHRONIC INFECTIONS. RECENT FINDINGS: PATTERNS OF GENE EXPRESSION IN VIRUS-SPECIFIC CD8 T CELLS ARE A RESULT OF A COMBINATION OF PRO AND INHIBITORY SIGNALS FROM ANTIGEN PRESENTATION (TCR-MEDIATED) AND CO-INHIBITORY RECEPTOR LIGATION (PD-1, 2B4). FURTHER, MEMORY-SPECIFIC TRANSCRIPTIONAL REGULATION OF 2B4 EXPRESSION AND SIGNALING IMPOSE A SELF-LIMITING SECONDARY EFFECTOR RESPONSE TO A PROLONGED VIRAL INFECTION. ADDITIONALLY, DIFFERENTIATION OF FUNCTIONAL MEMORY CD8 T CELLS IS COUPLED WITH ACQUISITION OF A REPRESSIVE EPIGENETIC PROGRAM FOR PD-1 EXPRESSION. HOWEVER, CHRONIC INFECTION PROVIDES A SIGNAL THAT BLOCKS THE ACQUISITION OF THESE EPIGENETIC MODIFICATIONS REINFORCING THE SUPPRESSION OF CYTOTOXIC LYMPHOCYTE (CTL) FUNCTIONS IN EXHAUSTED CELLS. SUMMARY: CURRENT FINDINGS SUGGEST THAT THE MECHANISM(S) THAT DELINEATE FUNCTIONAL MEMORY VERSUS EXHAUSTION ARE COUPLED WITH ACQUISITION OF TRANSCRIPTIONAL PROGRAMS AT THE EFFECTOR STAGE OF DIFFERENTIATION, REINFORCED BY CESSATION OR PERSISTENCE OF TCR SIGNALING. 2012