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 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 3 4967 33 PATHOLOGICAL CONDITIONS RE-SHAPE PHYSIOLOGICAL TREGS INTO PATHOLOGICAL TREGS. CD4(+)FOXP3(+) REGULATORY T CELLS (TREGS) ARE A SUBSET OF CD4 T CELLS THAT PLAY AN ESSENTIAL ROLE IN MAINTAINING PERIPHERAL IMMUNE TOLERANCE, CONTROLLING ACUTE AND CHRONIC INFLAMMATION, ALLERGY, AUTOIMMUNE DISEASES, AND ANTI-CANCER IMMUNE RESPONSES. OVER THE PAST 20 YEARS, SIGNIFICANT PROGRESS HAS BEEN MADE SINCE TREGS WERE FIRST CHARACTERIZED IN 1995. MANY CONCEPTS AND PRINCIPLES REGARDING TREGS GENERATION, PHENOTYPIC FEATURES, SUBSETS (TTREGS, PTREGS, ITREGS, AND ITREG35), TISSUE SPECIFICITY (CENTRAL TREGS, EFFECTOR TREGS, AND TISSUE RESIDENT TREGS), HOMEOSTASIS (HIGHLY DYNAMIC AND APOPTOTIC), REGULATION OF TREGS BY RECEPTORS FOR PAMPS AND DAMPS, TREG PLASTICITY (RE-DIFFERENTIATION TO OTHER CD4 T HELPER CELL SUBSETS, TH1, TH2, TFH AND TH17), AND EPIGENETIC REGULATION OF TREGS PHENOTYPES AND FUNCTIONS HAVE BEEN INNOVATED. IN THIS CONCISE REVIEW, WE WANT TO BRIEFLY ANALYZE THESE EIGHT NEW PROGRESSES IN THE STUDY OF TREGS. WE HAVE ALSO PROPOSED FOR THE FIRST TIME A NOVEL CONCEPT THAT "PHYSIOLOGICAL TREGS" HAVE BEEN RE-SHAPED INTO "PATHOLOGICAL TREGS" IN VARIOUS PATHOLOGICAL ENVIRONMENTS. CONTINUING OF THE IMPROVEMENT IN OUR UNDERSTANDING ON THIS IMPORTANT CELLULAR COMPONENT ABOUT THE IMMUNE TOLERANCE AND IMMUNE SUPPRESSION, WOULD LEAD TO THE FUTURE DEVELOPMENT OF NOVEL THERAPEUTICS APPROACHES FOR ACUTE AND CHRONIC INFLAMMATORY DISEASES, ALLERGY, ALLOGENEIC TRANSPLANTATION-RELATED IMMUNITY, SEPSIS, AUTOIMMUNE DISEASES, AND CANCERS. 2015 4 5897 34 T FOLLICULAR HELPER CELL-DEPENDENT CLEARANCE OF A PERSISTENT VIRUS INFECTION REQUIRES T CELL EXPRESSION OF THE HISTONE DEMETHYLASE UTX. EPIGENETIC CHANGES, INCLUDING HISTONE METHYLATION, CONTROL T CELL DIFFERENTIATION AND MEMORY FORMATION, THOUGH THE ENZYMES THAT MEDIATE THESE PROCESSES ARE NOT CLEAR. WE SHOW THAT UTX, A HISTONE H3 LYSINE 27 (H3K27) DEMETHYLASE, SUPPORTS T FOLLICULAR HELPER (TFH) CELL RESPONSES THAT ARE ESSENTIAL FOR B CELL ANTIBODY GENERATION AND THE RESOLUTION OF CHRONIC VIRAL INFECTIONS. MICE WITH A T CELL-SPECIFIC UTX DELETION HAD FEWER TFH CELLS, REDUCED GERMINAL CENTER RESPONSES, LACKED VIRUS-SPECIFIC IMMUNOGLOBULIN G (IGG), AND WERE UNABLE TO RESOLVE CHRONIC LYMPHOCYTIC CHORIOMENINGITIS VIRUS INFECTIONS. UTX-DEFICIENT T CELLS SHOWED DECREASED EXPRESSION OF INTERLEUKIN-6 RECEPTOR-ALPHA AND OTHER TFH CELL-RELATED GENES THAT WERE ASSOCIATED WITH INCREASED H3K27 METHYLATION. ADDITIONALLY, TURNER SYNDROME SUBJECTS, WHO ARE PREDISPOSED TO CHRONIC EAR INFECTIONS, HAD REDUCED UTX EXPRESSION IN IMMUNE CELLS AND DECREASED CIRCULATING CD4(+) CXCR5(+) T CELL FREQUENCY. THUS, WE IDENTIFY A CRITICAL LINK BETWEEN UTX IN T CELLS AND IMMUNITY TO INFECTION. 2015 5 6009 31 THE ANTI-INFLAMMATORY MEDIATOR, VASOACTIVE INTESTINAL PEPTIDE, MODULATES THE DIFFERENTIATION AND FUNCTION OF TH SUBSETS IN RHEUMATOID ARTHRITIS. GENETIC BACKGROUND, EPIGENETIC MODIFICATIONS, AND ENVIRONMENTAL FACTORS TRIGGER AUTOIMMUNE RESPONSE IN RHEUMATOID ARTHRITIS (RA). SEVERAL PATHOGENIC INFECTIONS HAVE BEEN RELATED TO THE ONSET OF RA AND MAY CAUSE AN INADEQUATE IMMUNOLOGICAL TOLERANCE TOWARDS CRITICAL SELF-ANTIGENS LEADING TO CHRONIC JOINT INFLAMMATION AND AN IMBALANCE BETWEEN DIFFERENT T HELPER (TH) SUBSETS. VASOACTIVE INTESTINAL PEPTIDE (VIP) IS A MEDIATOR THAT MODULATES ALL THE STAGES COMPRISED BETWEEN THE ARRIVAL OF PATHOGENS AND TH CELL DIFFERENTIATION IN RA THROUGH ITS KNOWN ANTI-INFLAMMATORY AND IMMUNOMODULATORY ACTIONS. THIS "NEUROIMMUNOPEPTIDE" MODULATES THE PATHOGENIC ACTIVITY OF DIVERSE CELL SUBPOPULATIONS INVOLVED IN RA AS LYMPHOCYTES, FIBROBLAST-LIKE SYNOVIOCYTES (FLS), OR MACROPHAGES. IN ADDITION, VIP DECREASES THE EXPRESSION OF PATTERN RECOGNITION RECEPTOR (PRR) SUCH AS TOLL-LIKE RECEPTORS (TLRS) IN FLS FROM RA PATIENTS. THESE RECEPTORS ACT AS SENSORS OF PATHOGEN-ASSOCIATED MOLECULAR PATTERN (PAMP) AND DAMAGE-ASSOCIATED MOLECULAR PATTERN (DAMP) CONNECTING THE INNATE AND ADAPTIVE IMMUNE SYSTEM. MOREOVER, VIP MODULATES THE IMBALANCE BETWEEN TH SUBSETS IN RA, DECREASING PATHOGENIC TH1 AND TH17 SUBSETS AND FAVORING TH2 OR TREG PROFILE DURING THE DIFFERENTIATION/POLARIZATION OF NAIVE OR MEMORY TH CELLS. FINALLY, VIP REGULATES THE PLASTICITY BETWEEN THESES SUBSETS. IN THIS REVIEW, WE PROVIDE AN OVERVIEW OF VIP EFFECTS ON THE AFOREMENTIONED FEATURES OF RA PATHOLOGY. 2018 6 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 7 2793 22 FATE-MAPPING OF GM-CSF EXPRESSION IDENTIFIES A DISCRETE SUBSET OF INFLAMMATION-DRIVING T HELPER CELLS REGULATED BY CYTOKINES IL-23 AND IL-1BETA. PATHOGENIC LYMPHOCYTES INITIATE THE DEVELOPMENT OF CHRONIC INFLAMMATORY DISEASES. THE CYTOKINE GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR (GM-CSF) (ENCODED BY CSF2) IS A KEY COMMUNICATOR BETWEEN PATHOGENIC LYMPHOCYTES AND TISSUE-INVADING INFLAMMATORY PHAGOCYTES. HOWEVER, THE MOLECULAR PROPERTIES OF GM-CSF-PRODUCING CELLS AND THE MODE OF CSF2 REGULATION IN VIVO REMAIN UNCLEAR. TO SYSTEMATICALLY STUDY AND MANIPULATE GM-CSF(+) CELLS AND THEIR PROGENY IN VIVO, WE GENERATED A FATE-MAP AND REPORTER OF GM-CSF EXPRESSION MOUSE STRAIN (FROG). WE MAPPED THE PHENOTYPIC AND FUNCTIONAL PROFILE OF AUTO-AGGRESSIVE T HELPER (TH) CELLS DURING NEUROINFLAMMATION AND IDENTIFIED THE SIGNATURE AND PATHOGENIC MEMORY OF A DISCRETE ENCEPHALITOGENIC TH SUBSET. THESE CELLS REQUIRED INTERLEUKIN-23 RECEPTOR (IL-23R) AND IL-1R BUT NOT IL-6R SIGNALING FOR THEIR MAINTENANCE AND PATHOGENICITY. SPECIFIC ABLATION OF THIS SUBSET INTERRUPTED THE INFLAMMATORY CASCADE, DESPITE THE UNPERTURBED TISSUE ACCUMULATION OF OTHER TH SUBSETS (E.G., TH1 AND TH17), HIGHLIGHTING THAT GM-CSF EXPRESSION NOT ONLY MARKS PATHOGENIC TH CELLS, BUT THAT THIS SUBSET MEDIATES IMMUNOPATHOLOGY AND TISSUE DESTRUCTION. 2019 8 6293 30 THE PRO- AND ANTI-INFLAMMATORY POTENTIAL OF IL-12: THE DUAL ROLE OF TH1 CELLS. THE DIFFERENTIATION OF T-HELPER (TH) LYMPHOCYTES INTO VARIOUS TYPES OF T-HELPER EFFECTOR AND MEMORY CELLS WITH DISTINCT FUNCTIONS DEPENDING ON THE TYPE OF CONCOMITANT SIGNALS THEY RECEIVE UPON ACTIVATION IS A CRITICAL EVENT DETERMINING THE COURSE OF AN IMMUNE REACTION. TH1 CELLS CHARACTERIZED BY THE EXPRESSION OF IFN-GAMMA AND THE RECENTLY DESCRIBED TH17 CELLS PROMOTE INFLAMMATION AND ARE CRITICALLY INVOLVED IN THE INDUCTION AND MAINTENANCE OF AUTOIMMUNITY, WHEREAS THE SECRETION OF IL-4 IS A HALLMARK OF TH2 CELLS MEDIATING PROTECTION FROM PARASITES AND ALLERGY. ORIGINAL STIMULATION IN THE PRESENCE OF IL-12 RESULTS IN THE IMPRINTING OF TH1 MEMORY CELLS FOR THE EXPRESSION OF IFN-GAMMA BY EXPRESSION OF THE TRANSCRIPTION FACTOR T-BET AND EPIGENETIC MODIFICATION OF THE IFNGAMMA GENE. IT HAS BEEN DEMONSTRATED THAT TH1 CELLS ARE POTENT INDUCERS OF INFLAMMATION. HOWEVER, IN THE CHRONIC PHASE OF SUCH INFLAMMATION, THE REGULATORY POTENTIAL OF IL-12 AND TH1 CELLS THEMSELVES MAY PLAY AN IMPORTANT ROLE IN LIMITING IMMUNOPATHOLOGY. 2007 9 6210 17 THE INTERPLAY BETWEEN KERATINOCYTES AND IMMUNE CELLS IN THE PATHOGENESIS OF PSORIASIS. PSORIASIS IS A CHRONIC INFLAMMATORY SKIN DISEASE RESULTING FROM GENETIC, EPIGENETIC, ENVIRONMENTAL, AND LIFESTYLE FACTORS. TO DATE, SEVERAL IMMUNOPATHOGENIC MECHANISMS OF PSORIASIS HAVE BEEN ELUCIDATED, AND, IN THE CURRENT MODEL, THE CROSS TALK BETWEEN AUTOREACTIVE T CELLS AND RESIDENT KERATINOCYTES GENERATES INFLAMMATORY AND IMMUNE CIRCUITS RESPONSIBLE FOR THE INITIATION, PROGRESSION, AND PERSISTENCE OF THE DISEASE. SEVERAL AUTOANTIGENS DERIVED FROM KERATINOCYTES (I.E., LL37 CATHELECIDIN/NUCLEIC ACID COMPLEXES, NEWLY GENERATED LIPID ANTIGENS) HAVE BEEN IDENTIFIED, WHICH MAY TRIGGER INITIAL ACTIVATION OF T CELLS, PARTICULARLY IL-17-PRODUCING T CELLS, T HELPER (TH)1 AND TH22 CELLS. HENCE, LYMPHOKINES RELEASED IN SKIN LESIONS ARE PIVOTAL FOR KERATINOCYTE ACTIVATION AND PRODUCTION OF INFLAMMATORY MOLECULES, WHICH IN TURN LEAD TO AMPLIFICATION OF THE LOCAL IMMUNE RESPONSES. INTRINSIC GENETIC ALTERATIONS OF KERATINOCYTES IN THE ACTIVATION OF SIGNAL TRANSDUCTION PATHWAYS DEPENDENT ON T-CELL-DERIVED CYTOKINES ARE ALSO FUNDAMENTAL. THE CURRENT REVIEW EMPHASIZES THE ABERRANT INTERPLAY OF IMMUNE CELLS AND SKIN-RESIDENT KERATINOCYTES IN ESTABLISHING AND SUSTAINING INFLAMMATORY AND IMMUNE RESPONSES IN PSORIASIS. 2018 10 5896 32 T CELLS IN HEALTH AND DISEASE. T CELLS ARE CRUCIAL FOR IMMUNE FUNCTIONS TO MAINTAIN HEALTH AND PREVENT DISEASE. T CELL DEVELOPMENT OCCURS IN A STEPWISE PROCESS IN THE THYMUS AND MAINLY GENERATES CD4(+) AND CD8(+) T CELL SUBSETS. UPON ANTIGEN STIMULATION, NAIVE T CELLS DIFFERENTIATE INTO CD4(+) HELPER AND CD8(+) CYTOTOXIC EFFECTOR AND MEMORY CELLS, MEDIATING DIRECT KILLING, DIVERSE IMMUNE REGULATORY FUNCTION, AND LONG-TERM PROTECTION. IN RESPONSE TO ACUTE AND CHRONIC INFECTIONS AND TUMORS, T CELLS ADOPT DISTINCT DIFFERENTIATION TRAJECTORIES AND DEVELOP INTO A RANGE OF HETEROGENEOUS POPULATIONS WITH VARIOUS PHENOTYPE, DIFFERENTIATION POTENTIAL, AND FUNCTIONALITY UNDER PRECISE AND ELABORATE REGULATIONS OF TRANSCRIPTIONAL AND EPIGENETIC PROGRAMS. ABNORMAL T-CELL IMMUNITY CAN INITIATE AND PROMOTE THE PATHOGENESIS OF AUTOIMMUNE DISEASES. IN THIS REVIEW, WE SUMMARIZE THE CURRENT UNDERSTANDING OF T CELL DEVELOPMENT, CD4(+) AND CD8(+) T CELL CLASSIFICATION, AND DIFFERENTIATION IN PHYSIOLOGICAL SETTINGS. WE FURTHER ELABORATE THE HETEROGENEITY, DIFFERENTIATION, FUNCTIONALITY, AND REGULATION NETWORK OF CD4(+) AND CD8(+) T CELLS IN INFECTIOUS DISEASE, CHRONIC INFECTION AND TUMOR, AND AUTOIMMUNE DISEASE, HIGHLIGHTING THE EXHAUSTED CD8(+) T CELL DIFFERENTIATION TRAJECTORY, CD4(+) T CELL HELPER FUNCTION, T CELL CONTRIBUTIONS TO IMMUNOTHERAPY AND AUTOIMMUNE PATHOGENESIS. WE ALSO DISCUSS THE DEVELOPMENT AND FUNCTION OF GAMMADELTA T CELLS IN TISSUE SURVEILLANCE, INFECTION, AND TUMOR IMMUNITY. FINALLY, WE SUMMARIZED CURRENT T-CELL-BASED IMMUNOTHERAPIES IN BOTH CANCER AND AUTOIMMUNE DISEASES, WITH AN EMPHASIS ON THEIR CLINICAL APPLICATIONS. A BETTER UNDERSTANDING OF T CELL IMMUNITY PROVIDES INSIGHT INTO DEVELOPING NOVEL PROPHYLACTIC AND THERAPEUTIC STRATEGIES IN HUMAN DISEASES. 2023 11 1479 27 DIVERSE TARGETS OF THE TRANSCRIPTION FACTOR STAT3 CONTRIBUTE TO T CELL PATHOGENICITY AND HOMEOSTASIS. STAT3, AN ESSENTIAL TRANSCRIPTION FACTOR WITH PLEIOTROPIC FUNCTIONS, PLAYS CRITICAL ROLES IN THE PATHOGENESIS OF AUTOIMMUNITY. DESPITE RECENT DATA LINKING STAT3 WITH INFLAMMATORY BOWEL DISEASE, EXACTLY HOW IT CONTRIBUTES TO CHRONIC INTESTINAL INFLAMMATION IS NOT KNOWN. USING A T CELL TRANSFER MODEL OF COLITIS, WE FOUND THAT STAT3 EXPRESSION IN T CELLS WAS ESSENTIAL FOR THE INDUCTION OF BOTH COLITIS AND SYSTEMIC INFLAMMATION. STAT3 WAS CRITICAL IN MODULATING THE BALANCE OF T HELPER 17 (TH17) AND REGULATORY T (TREG) CELLS, AS WELL AS IN PROMOTING CD4(+) T CELL PROLIFERATION. WE USED CHROMATIN IMMUNOPRECIPITATION AND MASSIVE PARALLEL SEQUENCING (CHIP-SEQ) TO DEFINE THE GENOME-WIDE TARGETS OF STAT3 IN CD4(+) T CELLS. WE FOUND THAT STAT3 BOUND TO MULTIPLE GENES INVOLVED IN TH17 CELL DIFFERENTIATION, CELL ACTIVATION, PROLIFERATION, AND SURVIVAL, REGULATING BOTH EXPRESSION AND EPIGENETIC MODIFICATIONS. THUS, STAT3 ORCHESTRATES MULTIPLE CRITICAL ASPECTS OF T CELL FUNCTION IN INFLAMMATION AND HOMEOSTASIS. 2010 12 2787 38 EZH2-MEDIATED EPIGENETIC MODIFICATION IS REQUIRED FOR ALLOGENEIC T CELL-INDUCED LUPUS DISEASE. BACKGROUND: THE MECHANISMS INVOLVED IN THE PATHOGENESIS OF AUTOIMMUNE DISORDERS, INCLUDING SYSTEMIC LUPUS ERYTHEMATOSUS (SLE), HAVE NOT BEEN FULLY ELUCIDATED. SOME OF THESE MECHANISMS INVOLVE EPIGENETIC REGULATION OF GENE EXPRESSION. THE HISTONE METHYLTRANSFERASE EZH2 CONTRIBUTES TO EPIGENETIC REGULATION OF GENE EXPRESSION, IS HIGHLY EXPRESSED IN GERMINAL CENTER (GC) B CELLS AND FOLLICULAR T HELPER (T(FH)) CELLS, AND MAY BE INVOLVED IN LUPUS PATHOGENESIS. METHODS: THE MURINE BM12 MODEL OF LUPUS-LIKE CHRONIC GRAFT VERSUS HOST DISEASE (CGVHD) WAS INDUCED BY INTRA-PERITONEAL INJECTION OF NEGATIVELY ISOLATED ALLOGENEIC CD4(+) T CELLS. LUPUS-LIKE DISEASE DEVELOPMENT WAS MONITORED BY ELISA DETERMINATION OF SERUM ANTI-DSDNA AND ANTI-CHROMATIN ANTIBODY TITERS. IMMUNE CELL ACTIVATION AND EZH2 EXPRESSION WERE EVALUATED BY FLOW CYTOMETRY AND WESTERN BLOTTING. RESULTS: DECREASED AUTOANTIBODY PRODUCTION AND GC FORMATION ARE OBSERVED WHEN EZH2-DEFICIENT CD4(+) T CELLS ARE USED INSTEAD OF WILD-TYPE (WT) TO INDUCE CGVHD AND WHEN MICE THAT RECEIVE ALLOGENEIC WT DONOR T CELLS TO INDUCE CGVHD ARE TREATED WITH GSK503, AN EZH2-SPECIFIC INHIBITOR. IN THE BM12 CGVHD MODEL, WT DONOR T CELLS ARE NORMALLY FULLY ACTIVATED 1 WEEK AFTER INFUSION INTO AN ALLOGENEIC HOST, EXHIBIT A T(FH) CELL (PD-1(HI)/CXCR5(HI)) PHENOTYPE WITH UPREGULATED EZH2, AND ACTIVATE B CELLS TO FORM GERMINAL CENTERS (GCS). IN CONTRAST, EZH2-DEFICIENT DONOR T CELLS GENERATE FEWER T(FH) CELLS THAT FAIL TO ACTIVATE B CELLS OR PROMOTE GC FORMATION. DESPITE SIMILAR T-INDEPENDENT, LPS-INDUCED B CELL RESPONSES, OVA-IMMUNIZED CD4.EZH2-KO MICE HAD A SKEWED LOW-AFFINITY IGM PHENOTYPE IN COMPARISON TO SIMILARLY TREATED WT MICE. IN ADDITION, EARLY AFTER OVA IMMUNIZATION, MORE CD4(+) T CELLS FROM B6.CD4.EZH2-KO MICE HAD A CD44(LO)/CD62L(LO) PHENOTYPE, WHICH SUGGESTS ARRESTED OR DELAYED ACTIVATION, THAN CD4(+) T CELLS FROM OVALBUMIN-IMMUNIZED B6.WT MICE. CONCLUSION: EZH2 GENE DELETION OR PHARMACOLOGICAL EZH2 INHIBITION SUPPRESSES AUTOANTIBODY PRODUCTION AND GC FORMATION IN BM12 LUPUS-LIKE CGVHD AND DECREASES AFFINITY MATURATION AND ISOTYPE SWITCHING IN RESPONSE TO IMMUNIZATION WITH A T CELL-DEPENDENT ANTIGEN. EZH2 INHIBITION MAY BE USEFUL FOR THE TREATMENT OF LUPUS AND OTHER AUTOIMMUNE DISORDERS. 2020 13 3373 35 HISTONE MODULATION BLOCKS TREG-INDUCED FOXP3 BINDING TO THE IL-2 PROMOTER OF VIRUS-SPECIFIC CD8(+) T CELLS FROM FELINE IMMUNODEFICIENCY VIRUS-INFECTED CATS. CD8(+) T CELLS ARE CRITICAL FOR CONTROLLING HIV INFECTION. DURING THE CHRONIC PHASE OF LENTIVIRAL INFECTION, CD8(+) T CELLS LOSE THEIR PROLIFERATIVE CAPACITY AND EXHIBIT IMPAIRED ANTIVIRAL FUNCTION. THIS LOSS OF CD8(+) T CELL FUNCTION IS DUE, IN PART, TO CD4(+)CD25(+) T REGULATORY (TREG) CELL-MEDIATED SUPPRESSION. OUR RESEARCH GROUP HAS DEMONSTRATED THAT LENTIVIRUS-ACTIVATED CD4(+)CD25(+) TREG CELLS INDUCE THE REPRESSIVE TRANSCRIPTION FACTOR FORKHEAD BOX P3 (FOXP3) IN AUTOLOGOUS CD8(+) T CELLS FOLLOWING CO-CULTURE. WE HAVE RECENTLY REPORTED THAT TREG-INDUCED FOXP3 BINDS THE INTERLEUKIN-2 (IL-2), INTERFERON-GAMMA (IFN- GAMMA), AND TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA) PROMOTERS IN VIRUS-SPECIFIC CD8(+) T CELLS. THESE DATA SUGGEST AN IMPORTANT ROLE OF FOXP3-MEDIATED CD8(+) T CELL DYSFUNCTION IN LENTIVIRAL INFECTION. TO ELUCIDATE THE MECHANISM OF THIS SUPPRESSION, WE PREVIOUSLY REPORTED THAT DECREASED METHYLATION FACILITATES FOXP3 BINDING IN MITOGEN-ACTIVATED CD8(+) T CELLS FROM FELINE IMMUNODEFICIENCY VIRUS (FIV)-INFECTED CATS. WE DEMONSTRATED THE REDUCED BINDING OF FOXP3 TO THE IL-2 PROMOTER BY INCREASING METHYLATION OF CD8(+) T CELLS. IN THE STUDIES PRESENTED HERE, WE ASK IF ANOTHER FORM OF EPIGENETIC MODULATION MIGHT ALLEVIATE FOXP3-MEDIATED SUPPRESSION IN CD8(+) T CELLS. WE HYPOTHESIZED THAT DECREASING HISTONE ACETYLATION IN VIRUS-SPECIFIC CD8(+) T CELLS WOULD DECREASE TREG-INDUCED FOXP3 BINDING TO THE IL-2 PROMOTER. INDEED, USING ANACARDIC ACID (AA), A KNOWN HISTONE ACETYL TRANSFERASE (HAT) INHIBITOR, WE DEMONSTRATE A REDUCTION IN FOXP3 BINDING TO THE IL-2 PROMOTER IN VIRUS-SPECIFIC CD8(+) T CELLS CO-CULTURED WITH AUTOLOGOUS TREG CELLS. THESE DATA IDENTIFY A NOVEL MECHANISM OF FOXP3-MEDIATED CD8(+) T CELL DYSFUNCTION DURING LENTIVIRAL INFECTION. 2018 14 233 23 ADAPTIVE T CELL TUNING IN IMMUNE REGULATION AND IMMUNOTHERAPY OF AUTOIMMUNE DISEASES(?). LYMPHOCYTE RECEPTORS CONFER ANTIGEN SPECIFICITY ON THE ADAPTIVE IMMUNE RESPONSE. INCREASING EVIDENCE POINTS TO THE ROLE OF ADAPTIVE TUNING PARTICULARLY AMONGST CD4(+) T CELL RESPONSES. THIS REVIEW SUMMARISES HOW T CELL TUNING IMPACTS ON CRITICALLY IMPORTANT ASPECTS OF IMMUNE REGULATION INCLUDING THYMIC SELECTION, THE IMMUNE RESPONSE TO CHRONIC ANTIGEN EXPOSURE AND ANTIGEN-SPECIFIC IMMUNOTHERAPY OF AUTOIMMUNE CONDITIONS. RECENT WORK HAS REVEALED A NOVEL MECHANISM FOR T CELL ANERGY AND REGULATORY TYPE 1 T CELL DIFFERENTIATION THROUGH A LIMITATION OF T CELL RECEPTOR MEDIATED SIGNALLING COMBINED WITH EPIGENETIC PRIMING OF TOLERANCE ASSOCIATED GENES. 2022 15 5898 30 T(H)2 CELL DEVELOPMENT AND FUNCTION. T HELPER 2 (T(H)2) CELLS ORCHESTRATE PROTECTIVE TYPE 2 IMMUNE RESPONSES, SUCH AS THOSE THAT TARGET HELMINTHS AND FACILITATE TISSUE REPAIR, BUT ALSO CONTRIBUTE TO CHRONIC INFLAMMATORY DISEASES, SUCH AS ASTHMA AND ALLERGY. HERE, WE REVIEW RECENT INSIGHTS INTO HOW DIVERSE MOLECULAR SIGNALS FROM CELLULAR SOURCES, INCLUDING DENDRITIC CELLS, INNATE LYMPHOID CELLS AND THE EPITHELIUM, ARE INTEGRATED BY T CELLS TO GUIDE THE TRANSCRIPTIONAL AND EPIGENETIC CHANGES NECESSARY FOR T(H)2 CELL DIFFERENTIATION. OUR IMPROVED UNDERSTANDING OF THESE PATHWAYS HAS OPENED NEW AVENUES FOR THERAPEUTICALLY TARGETING T(H)2 CELLS IN ASTHMA AND ALLERGY. THE ADVENT OF COMPREHENSIVE SINGLE-CELL TRANSCRIPTOMICS ALONG WITH IMPROVEMENTS IN SINGLE-CELL PROTEOMICS AND THE GENERATION OF NOVEL IN VIVO CELL FATE MAPPING TECHNIQUES PROMISE TO EXPAND OUR UNDERSTANDING OF T CELL DIVERSITY AND OFFER NEW INSIGHT INTO DISEASE-RELATED HETEROGENEITY AND PLASTICITY OF T(H) CELL RESPONSES. 2018 16 3789 21 INTERLEUKIN 17 CONTRIBUTES TO THE CHRONICITY OF INFLAMMATORY DISEASES SUCH AS RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY DISEASE LEADING TO JOINT DESTRUCTION AND BONE RESORPTION. THE PROINFLAMMATORY CYTOKINE INTERLEUKIN 17 (IL-17), PRIMARILY PRODUCED BY TH17 CELLS, HAS BEEN SHOWN TO BE INVOLVED IN ALL STAGES OF THE DISEASE AND TO BE AN IMPORTANT CONTRIBUTOR OF RA CHRONICITY. THREE MAJOR PROCESSES DRIVE THE IL-17-MEDIATED CHRONICITY. SEVERAL EPIGENETIC EVENTS, ENHANCED IN RA PATIENTS, LEAD TO THE INCREASED PRODUCTION OF IL-17 BY TH17 CELLS. IL-17 THEN INDUCES THE PRODUCTION OF SEVERAL INFLAMMATORY MEDIATORS IN THE DISEASED SYNOVIUM, WHICH ARE FURTHER SYNERGISTICALLY ENHANCED VIA COMBINATIONS OF IL-17 WITH OTHER CYTOKINES. IL-17 ALSO PROMOTES THE SURVIVAL OF BOTH THE SYNOVIOCYTES AND INFLAMMATORY CELLS AND PROMOTES THE MATURATION OF THESE IMMUNE CELLS. THIS LEADS TO AN INCREASED NUMBER OF SYNOVIOCYTES AND INFLAMMATORY CELLS IN THE SYNOVIAL FLUID AND IN THE SYNOVIUM LEADING TO THE HYPERPLASIA AND EXACERBATED INFLAMMATION OBSERVED IN JOINTS OF RA PATIENTS. FURTHERMORE, THESE IL-17-DRIVEN EVENTS INITIATE SEVERAL FEEDBACK-LOOP MECHANISMS LEADING TO INCREASED EXPANSION OF TH17 CELLS AND THEREBY INCREASED PRODUCTION OF IL-17. IN THIS REVIEW, WE AIM TO DEPICT A COMPLETE PICTURE OF THE IL-17-DRIVEN VICIOUS CIRCLE LEADING TO RA CHRONICITY AND TO PINPOINT THE KEY ASPECTS THAT REQUIRE FURTHER EXPLORATION. 2014 17 6327 28 THE ROLE OF CD4(+) RESIDENT MEMORY T CELLS IN LOCAL IMMUNITY IN THE MUCOSAL TISSUE - PROTECTION VERSUS PATHOLOGY. MEMORY T CELLS ARE CRUCIAL FOR BOTH LOCAL AND SYSTEMIC PROTECTION AGAINST PATHOGENS OVER A LONG PERIOD OF TIME. THREE MAJOR SUBSETS OF MEMORY T CELLS; EFFECTOR MEMORY T (T(EM)) CELLS, CENTRAL MEMORY T (T(CM)) CELLS, AND TISSUE-RESIDENT MEMORY T (T(RM)) CELLS HAVE BEEN IDENTIFIED. THE MOST RECENTLY IDENTIFIED SUBSET, T(RM) CELLS, IS CHARACTERIZED BY THE EXPRESSION OF THE C-TYPE LECTIN CD69 AND/OR THE INTEGRIN CD103. T(RM) CELLS PERSIST LOCALLY AT SITES OF MUCOSAL TISSUE, SUCH AS THE LUNG, WHERE THEY PROVIDE FRONTLINE DEFENSE AGAINST VARIOUS PATHOGENS. IMPORTANTLY, HOWEVER, T(RM) CELLS ARE ALSO INVOLVED IN SHAPING THE PATHOLOGY OF INFLAMMATORY DISEASES. A NUMBER OF PIONEERING STUDIES REVEALED IMPORTANT ROLES OF CD8(+) T(RM) CELLS, PARTICULARLY THOSE IN THE LOCAL CONTROL OF VIRAL INFECTION. HOWEVER, THE PROTECTIVE FUNCTION AND PATHOGENIC ROLE OF CD4(+) T(RM) CELLS THAT RESIDE WITHIN THE MUCOSAL TISSUE REMAIN LARGELY UNKNOWN. IN THIS REVIEW, WE DISCUSS THE AMBIVALENT FEATURE OF CD4(+) T(RM) CELLS IN THE PROTECTIVE AND PATHOLOGICAL IMMUNE RESPONSES. WE ALSO REVIEW THE TRANSCRIPTIONAL AND EPIGENETIC CHARACTERISTICS OF CD4(+) T(RM) CELLS IN THE LUNG THAT HAVE BEEN ELUCIDATED BY RECENT TECHNICAL APPROACHES. A BETTER UNDERSTANDING OF THE FUNCTION OF CD4(+) T(RM) CELLS IS CRUCIAL FOR THE DEVELOPMENT OF BOTH EFFECTIVE VACCINATION AGAINST PATHOGENS AND NEW THERAPEUTIC STRATEGIES FOR INTRACTABLE INFLAMMATORY DISEASES, SUCH AS INFLAMMATORY BOWEL DISEASES AND CHRONIC ALLERGIC DISEASES. 2021 18 5223 32 PRIMARY MURINE CD4+ T CELLS FAIL TO ACQUIRE THE ABILITY TO PRODUCE EFFECTOR CYTOKINES WHEN ACTIVE RAS IS PRESENT DURING TH1/TH2 DIFFERENTIATION. CONSTITUTIVE RAS SIGNALING HAS BEEN SHOWN TO AUGMENT IL-2 PRODUCTION, REVERSE ANERGY, AND FUNCTIONALLY REPLACE MANY ASPECTS OF CD28 CO-STIMULATION IN CD4+ T CELLS. THESE DATA RAISE THE POSSIBILITY THAT INTRODUCTION OF ACTIVE RAS INTO PRIMARY T CELLS MIGHT RESULT IN IMPROVED FUNCTIONALITY IN PATHOLOGIC SITUATIONS OF T CELL DYSFUNCTION, SUCH AS CANCER OR CHRONIC VIRAL INFECTION. TO TEST THE BIOLOGIC EFFECTS OF ACTIVE RAS IN PRIMARY T CELLS, CD4+ T CELLS FROM COXSACKIE-ADENOVIRUS RECEPTOR TRANSGENIC MICE WERE TRANSDUCED WITH AN ADENOVIRUS ENCODING ACTIVE RAS. AS EXPECTED, ACTIVE RAS AUGMENTED IL-2 PRODUCTION IN NAIVE CD4+ T CELLS. HOWEVER, WHEN CELLS WERE CULTURED FOR 4 DAYS UNDER CONDITIONS TO PROMOTE EFFECTOR CELL DIFFERENTIATION, ACTIVE RAS INHIBITED THE ABILITY OF CD4+ T CELLS TO ACQUIRE A TH1 OR TH2 EFFECTOR CYTOKINE PROFILE. THIS DIFFERENTIATION DEFECT WAS NOT DUE TO DEFICIENT STAT4 OR STAT6 ACTIVATION BY IL-12 OR IL-4, RESPECTIVELY, NOR WAS IT ASSOCIATED WITH DEFICIENT INDUCTION OF T-BET AND GATA-3 EXPRESSION. IMPAIRED EFFECTOR CYTOKINE PRODUCTION IN ACTIVE RAS-TRANSDUCED CELLS WAS ASSOCIATED WITH DEFICIENT DEMETHYLATION OF THE IL-4 GENE LOCUS. OUR RESULTS INDICATE THAT, DESPITE AUGMENTING ACUTE ACTIVATION OF NAIVE T CELLS, CONSTITUTIVE RAS SIGNALING INHIBITS THE ABILITY OF CD4+ T CELLS TO PROPERLY DIFFERENTIATE INTO TH1/TH2 EFFECTOR CYTOKINE-PRODUCING CELLS, IN PART BY INTERFERING WITH EPIGENETIC MODIFICATION OF EFFECTOR GENE LOCI. ALTERNATIVE STRATEGIES TO POTENTIATE RAS PATHWAY SIGNALING IN T CELLS IN A MORE REGULATED FASHION SHOULD BE CONSIDERED AS A THERAPEUTIC APPROACH TO IMPROVE IMMUNE RESPONSES IN VIVO. 2014 19 5049 23 PHARMACOLOGICAL INHIBITION OF RORC2 ENHANCES HUMAN TH17-TREG STABILITY AND FUNCTION. INFLAMMATORY BOWEL DISEASES (IBD) ARE CHRONIC CONDITIONS THAT RESULT FROM UNCONTROLLED INTESTINAL INFLAMMATION. PATHOGENIC TH17 CELLS, CHARACTERIZED BY PRODUCTION OF IL-17A IN THE ABSENCE OF IL-10, ARE THOUGHT TO CONTRIBUTE TO THIS INFLAMMATION, BUT IN HUMANS, ANTIBODY-MEDIATED BLOCKADE OF IL-17A IS AN INEFFECTIVE IBD THERAPY WHEREAS IL-23 BLOCKADE IS EFFECTIVE. HERE, WE INVESTIGATED THE EFFECTS OF PHARMACOLOGICAL INHIBITION OF RORC2, THE TH17 CELL LINEAGE-DEFINING TRANSCRIPTION FACTOR, ON IN VIVO-DIFFERENTIATED HUMAN TH17 CELLS AND TH17-LIKE TREGS (TH17-TREGS). BMS-336, A SMALL MOLECULE RORC2 INVERSE AGONIST, INHIBITED EXPRESSION OF RORC2-REGULATED GENES IN PERIPHERAL TH17 CELLS (CD4(+) CD25(-) CD127(+) CXCR3(-) CCR4(+) CCR6(+) ) IN A DOSE-DEPENDENT MANNER, WITH SIMILAR INHIBITORY EFFECTS ON LAMINAR PROPRIA MONONUCLEAR CELLS FROM IBD AND NON-IBD SUBJECTS. EXPOSURE OF PERIPHERAL TH17-TREGS (CD4(+) CD25(HI) CD127(LO) CXCR3(-) CCR4(+) CCR6(+) ) TO BMS-336 ALSO INHIBITED IL-17A PRODUCTION AND PREVENTED INFLAMMATORY CYTOKINE-INDUCED DESTABILIZATION, AS EVIDENCED BY PRESERVED FOXP3 EXPRESSION AND EPIGENETIC STATUS OF THE TREG-SPECIFIC DEMETHYLATION REGION. IN PARALLEL, RORC2 INHIBITION INCREASED THE PRODUCTION OF IL-10 IN TH17-TREGS, RESULTING IN ENHANCED SUPPRESSION OF INFLAMMATORY CYTOKINES FROM MYELOID CELLS. THUS, VIA ITS ABILITY TO SIMULTANEOUSLY INHIBIT TH17 CELLS AND ENHANCE THE STABILITY AND FUNCTION OF TH17-TREGS, PHARMACOLOGICAL INHIBITION OF RORC2 IS A PROMISING APPROACH TO SUPPRESS INFLAMMATION AND PROMOTE IMMUNE REGULATION IN IBD. 2020 20 6535 25 TRANSCRIPTIONAL REGULATION OF THE ANTI-INFLAMMATORY CYTOKINE IL-10 IN ACQUIRED IMMUNE CELLS. ALTHOUGH THE MAJOR ROLE OF THE IMMUNE RESPONSE IS HOST DEFENSE FROM A WIDE RANGE OF POTENTIALLY PATHOGENIC MICROORGANISMS, EXCESS IMMUNE RESPONSES CAN RESULT IN SEVERE HOST DAMAGE. THE HOST THUS REQUIRES ANTI-INFLAMMATORY MECHANISMS TO PREVENT REACTIVITY TO SELF. INTERLEUKIN-10 (IL-10) IS A CYTOKINE WITH BROAD ANTI-INFLAMMATORY PROPERTIES INVOLVED IN THE PATHOGENESIS OF VARIOUS DISEASES. IL-10 WAS ORIGINALLY DESCRIBED AS A T HELPER (T(H)2) DERIVED CYTOKINE, BUT FURTHER STUDIES INDICATED THAT IL-10 IS EXPRESSED NOT ONLY BY MANY CELLS OF THE ADAPTIVE IMMUNE SYSTEM, INCLUDING T AND B CELLS, BUT ALSO BY THE INNATE IMMUNE CELLS, INCLUDING DENDRITIC CELLS (DCS), MACROPHAGES, MAST CELLS, AND NATURAL KILLER (NK) CELLS. IN ADDITION, IL-10 CAN BE INDUCED IN T(H)1 AND T(H)17 CELLS BY CHRONIC INFLAMMATION AS A SYSTEM OF FEEDBACK REGULATION. IN THIS REVIEW, WE FOCUS ON THE MOLECULAR MECHANISMS UNDERLYING IL10 GENE EXPRESSION IN ADAPTIVE IMMUNE CELLS AND SUMMARIZE THE RECENT PROGRESSES IN EPIGENETIC AND TRANSCRIPTIONAL REGULATION OF THE IL10 GENE. UNDERSTANDING THE TRANSCRIPTIONAL REGULATORY EVENTS MAY HELP IN THE DEVELOPMENT OF NEW STRATEGIES TO CONTROL INFLAMMATORY DISEASES. 2012