1 4123 188 MECHANISMS OF DIMETHYLBENZANTHRACENE-INDUCED IMMUNOTOXICITY. TRADITIONAL METHODS FOR TOXICOLOGICAL ASSESSMENT HAVE IMPLICATED THE IMMUNE SYSTEM AS A FREQUENT TARGET ORGAN OF TOXIC INSULT FOLLOWING CHRONIC EXPOSURE TO CERTAIN ENVIRONMENTAL CHEMICALS, RADIATION OR THERAPEUTIC DRUGS (XENOBIOTICS). IMMUNOTOXICITY IS EXPRESSED AS AUTOIMMUNITY, CHEMICAL HYPERSENSITIVITY OR IMMUNOSUPPRESSION. A TIERED APPROACH FOR CHARACTERIZING CHEMICAL AND DRUG-INDUCED IMMUNOMODULATION HAS BEEN DEVELOPED AND VALIDATED IN LABORATORY ANIMALS. POLYCYCLIC AROMATIC HYDROCARBONS (PAH) HAVE BEEN STUDIED BECAUSE OF THEIR UBIQUITOUS PRESENCE IN THE ENVIRONMENT AND CARCINOGENIC POTENTIAL. SINCE IMMUNOSUPPRESSION INDUCED BY PAH CARCINOGENS HAS BEEN IMPLICATED AS AN EPIGENETIC MECHANISM IN THE OUTGROWTH OF INITIATED CELLS, THIS TIERED APPROACH WAS USED TO CHARACTERIZE THE MECHANISM OF PAH IMMUNOSUPPRESSIVE CAPACITY. PREVIOUSLY, STUDIES IN THIS LABORATORY HAVE DEMONSTRATED THAT SUBCHRONIC EXPOSURE OF B6C3F1 MICE TO PAH CARCINOGENS SUPPRESSES BOTH HUMORAL IMMUNITY (HI) AND CELL-MEDIATED IMMUNITY (CMI), CONCURRENTLY WITH DECREASED RESISTANCE TO TUMOR CHALLENGE. THE POTENT CARCINOGENIC PAH, 7,12-DIMETHYLBENZ[A]ANTHRACENE (DMBA) WAS SUBCHRONICALLY ADMINISTERED SUBCUTANEOUSLY AT 5, 50, OR 100 MICROGRAMS/G OF BODY WEIGHT. NATURAL KILLER (NK) CELL TUMOR CYTOLYSIS, GENERATION OF CYTOTOXIC T-CELLS (CTL), AND LYMPHOPROLIFERATION TO MITOGENS AND ALLOGENEIC SPLENOCYTES IN MIXED LEUKOCYTE CULTURES (MLC) WERE QUANTITATED 3-5 DAYS AFTER EXPOSURE TO ASSESS CMI. MITOGEN AND ALLOANTIGEN-INDUCED PROLIFERATION (MLC) OF SPLENOCYTES WAS SUPPRESSED UP TO 90%. CTL AND NK TUMOR CYTOLYSIS OF RADIOLABELLED TARGET CELLS WERE SIMILARLY DEPRESSED UP TO 88 AND 82%, RESPECTIVELY. IMPAIRMENT OF MLC OR CTL RESPONSES CORRELATED WITH INCREASED SUSCEPTIBILITY TO CHALLENGE WITH PYB6 SARCOMA CELLS. HI WAS MEASURED BY QUANTITATING THE NUMBER OF ANTIBODY (IGM) PLAQUE-FORMING CELLS (PFC) PRODUCED IN RESPONSE TO T-CELL DEPENDENT ANTIGEN CHALLENGE (SHEEP ERYTHROCYTES) AND WAS SIMILARLY SUPPRESSED UP TO 95%. TO UNDERSTAND THE MECHANISM OF PAH-INDUCED IMMUNOTOXICITY, SPLENOCYTES FROM DMBA-EXPOSED MICE WERE SENSITIZED TO ALLOANTIGENS IN THE PRESENCE OF INTERLEUKIN-2 (IL-2) BECAUSE THERE WERE INDICATIONS THAT T-HELPER CELL FUNCTION WAS SUPPRESSED. IN THESE PRELIMINARY STUDIES, CTL SUPPRESSION COULD BE COMPLETELY RESTORED BY THE ADDITION OF THE T-CELL GROWTH SUPPORTING LYMPHOKINE (IL-2) DURING THE INDUCTIVE PHASE OF CTL GENERATION, SUGGESTING THAT DMBA EXPOSURE DIRECTLY OR INDIRECTLY INDUCED DEFICITS IN T-HELPER CELL FUNCTION. 1985 2 6117 33 THE EPIGENETIC DRUG TRICHOSTATIN A AMELIORATES EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS VIA T CELL TOLERANCE INDUCTION AND IMPAIRED INFLUX OF T CELLS INTO THE SPINAL CORD. MULTIPLE SCLEROSIS IS A T CELL MEDIATED CHRONIC DEMYELINATING DISEASE OF THE CENTRAL NERVOUS SYSTEM. ALTHOUGH CURRENTLY AVAILABLE THERAPIES REDUCE RELAPSES, THEY DO NOT FACILITATE TOLERIZATION OF MYELIN ANTIGEN-SPECIFIC T LYMPHOCYTES TO ENSURE PROLONGED PROTECTION AGAINST MULTIPLE SCLEROSIS. HERE, WE SHOW THAT TREATMENT OF NOD MICE WITH THE HISTONE DEACETYLASE INHIBITOR, TRICHOSTATIN A AFFORDS ROBUST PROTECTION AGAINST MYELIN PEPTIDE INDUCED EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS, A MOUSE MODEL OF MULTIPLE SCLEROSIS. PROTECTION WAS ACCOMPANIED BY HISTONE HYPERACETYLATION, AND REDUCED INFLAMMATION AND AXONAL DAMAGE IN THE SPINAL CORD. DRUG TREATMENT DIMINISHED THE GENERATION OF CD4(+) MEMORY T CELLS AND INDUCED TOLERANCE IN CD4(+) T CELLS RECOGNIZING THE IMMUNIZING MYELIN PEPTIDE. DURING THE EARLY IMMUNIZATION PERIOD, CD4(+) T CELLS PRODUCING GM-CSF+IFN-GAMMA, GM-CSF+IL-17A, AS WELL AS THOSE EXPRESSING BOTH IL-17A+IFN-GAMMA (DOUBLE-PRODUCERS) WERE DETECTED IN THE SECONDARY LYMPHOID ORGANS FOLLOWED BY THE APPEARANCE OF CELLS PRODUCING IFN-GAMMA AND GM-CSF. ON THE OTHER HAND, IFN-GAMMA PRODUCING TH1 CELLS APPEAR FIRST IN THE SPINAL CORD FOLLOWED BY CELLS PRODUCING IL-17A AND GM-CSF. TREATMENT WITH TRICHOSTATIN A SUBSTANTIALLY REDUCED THE FREQUENCIES OF ALL T CELLS SECRETING VARIOUS LYMPHOKINES BOTH IN THE PERIPHERY AND IN THE SPINAL CORD. THESE DATA INDICATE THAT EPIGENETIC MODIFICATIONS INDUCED BY HISTONE HYPERACETYLATION FACILITATES T CELL TOLERANCE INDUCTION IN THE PERIPHERY LEADING TO REDUCED MIGRATION OF T CELLS TO THE SPINAL CORD AND MITIGATION OF NEURONAL DAMAGE AND IMPROVED CLINICAL OUTCOME. THESE RESULTS SUGGEST THAT EPIGENETIC MODULATION OF THE GENOME MAY SIMILARLY OFFER BENEFITS TO MULTIPLE SCLEROSIS PATIENTS VIA ABROGATING THE FUNCTION OF ENCEPHALITOGENIC T LYMPHOCYTES WITHOUT EXERTING SEVERE SIDE EFFECTS ASSOCIATED WITH CURRENTLY USED DISEASE-MODIFYING THERAPIES. 2017 3 6210 21 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 4 4957 30 PATHOGENESIS OF ENDOMETRIOSIS: THE GENETIC/EPIGENETIC THEORY. OBJECTIVE: TO STUDY THE PATHOPHYSIOLOGY OF ENDOMETRIOSIS. DESIGN: OVERVIEW OF OBSERVATIONS ON ENDOMETRIOSIS. SETTING: NOT APPLICABLE. PATIENT(S): NONE. INTERVENTIONS(S): NONE. MAIN OUTCOME MEASURE(S): THE HYPOTHESIS IS COMPATIBLE WITH ALL OBSERVATIONS. RESULT(S): ENDOMETRIOSIS, ENDOMETRIUM-LIKE TISSUE OUTSIDE THE UTERUS, HAS A VARIABLE MACROSCOPIC APPEARANCE AND A POORLY UNDERSTOOD NATURAL HISTORY. IT IS A HEREDITARY AND HETEROGENEOUS DISEASE WITH MANY BIOCHEMICAL CHANGES IN THE LESIONS, WHICH ARE CLONAL IN ORIGIN. IT IS ASSOCIATED WITH PAIN, INFERTILITY, ADENOMYOSIS, AND CHANGES IN THE JUNCTIONAL ZONE, PLACENTATION, IMMUNOLOGY, PLASMA, PERITONEAL FLUID, AND CHRONIC INFLAMMATION OF THE PERITONEAL CAVITY. THE SAMPSON HYPOTHESIS OF IMPLANTED ENDOMETRIAL CELLS FOLLOWING RETROGRADE MENSTRUATION, ANGIOGENIC SPREAD, LYMPHOGENIC SPREAD, OR THE METAPLASIA THEORY CANNOT EXPLAIN ALL OBSERVATIONS IF METAPLASIA IS DEFINED AS CELLS WITH REVERSIBLE CHANGES AND AN ABNORMAL BEHAVIOR/MORPHOLOGY DUE TO THE ABNORMAL ENVIRONMENT. WE PROPOSE A POLYGENETIC/POLYEPIGENETIC MECHANISM. THE SET OF GENETIC AND EPIGENETIC INCIDENTS TRANSMITTED AT BIRTH COULD EXPLAIN THE HEREDITARY ASPECTS, THE PREDISPOSITION, AND THE ENDOMETRIOSIS-ASSOCIATED CHANGES IN THE ENDOMETRIUM, IMMUNOLOGY, AND PLACENTATION. TO DEVELOP TYPICAL, CYSTIC OVARIAN OR DEEP ENDOMETRIOSIS LESIONS, A VARIABLE SERIES OF ADDITIONAL TRANSMISSIBLE GENETIC AND EPIGENETIC INCIDENTS ARE REQUIRED TO OCCUR IN A CELL WHICH MAY VARY FROM ENDOMETRIAL TO STEM CELLS. SUBTLE LESIONS ARE VIEWED AS ENDOMETRIUM IN A DIFFERENT ENVIRONMENT UNTIL ADDITIONAL INCIDENTS OCCUR. TYPICAL CYSTIC OVARIAN OR DEEP ENDOMETRIOSIS LESIONS ARE HETEROGENEOUS AND REPRESENT THREE DIFFERENT DISEASES. CONCLUSION(S): THE GENETIC EPIGENETIC THEORY IS COMPATIBLE WITH ALL OBSERVATIONS ON ENDOMETRIOSIS. IMPLICATIONS FOR TREATMENT AND PREVENTION ARE DISCUSSED. 2019 5 6111 19 THE EPIGENETIC ARCHITECTURE AT GENE PROMOTERS DETERMINES CELL TYPE-SPECIFIC LPS TOLERANCE. SYNOVIAL FIBROBLASTS (SF) DRIVE INFLAMMATION AND JOINT DESTRUCTION IN CHRONIC ARTHRITIS. HERE WE SHOW THAT SF POSSESS A DISTINCT TYPE OF LPS TOLERANCE COMPARED TO MACROPHAGES AND OTHER TYPES OF FIBROBLASTS. IN SF AND DERMAL FIBROBLASTS, GENES THAT WERE NON-TOLERIZABLE AFTER REPEATED LPS STIMULATION INCLUDED PRO-INFLAMMATORY CYTOKINES, CHEMOKINES AND MATRIX METALLOPROTEINASES, WHEREAS ANTI-VIRAL GENES WERE TOLERIZABLE. IN MACROPHAGES, ALL MEASURED GENES WERE TOLERIZABLE, WHEREAS IN GINGIVAL AND FORESKIN FIBROBLASTS THESE GENES WERE NON-TOLERIZABLE. REPEATED STIMULATION OF SF WITH LPS RESULTED IN LOSS OF ACTIVATING HISTONE MARKS ONLY IN PROMOTERS OF TOLERIZABLE GENES. THE EPIGENETIC LANDSCAPE AT PROMOTERS OF TOLERIZABLE GENES WAS SIMILAR IN UNSTIMULATED SF AND MONOCYTES, WHEREAS THE BASAL CONFIGURATION OF HISTONE MARKS PROFOUNDLY DIFFERED IN GENES THAT WERE NON-TOLERIZABLE IN SF ONLY. OUR DATA SUGGEST THAT THE EPIGENETIC CONFIGURATION AT GENE PROMOTERS REGULATES CELL-SPECIFIC LPS-INDUCED RESPONSES AND PRIMES SF TO SUSTAIN THEIR INFLAMMATORY RESPONSE IN CHRONIC ARTHRITIS. 2017 6 236 28 ADENOMYOSIS: MECHANISMS AND PATHOGENESIS. ADENOMYOSIS IS A COMMON DISORDER OF THE UTERUS, AND IS ASSOCIATED WITH AN ENLARGED UTERUS, HEAVY MENSTRUAL BLEEDING (HMB), PELVIC PAIN, AND INFERTILITY. IT IS CHARACTERIZED BY ENDOMETRIAL EPITHELIAL CELLS AND STROMAL FIBROBLASTS ABNORMALLY FOUND IN THE MYOMETRIUM WHERE THEY ELICIT HYPERPLASIA AND HYPERTROPHY OF SURROUNDING SMOOTH MUSCLE CELLS. WHILE BOTH THE MECHANISTIC PROCESSES AND THE PATHOGENESIS OF ADENOMYOSIS ARE UNCERTAIN, SEVERAL THEORIES HAVE BEEN PUT FORWARD ADDRESSING HOW THIS DISEASE DEVELOPS. THESE INCLUDE INTRINSIC OR INDUCED (1) MICROTRAUMA OF THE ENDOMETRIAL-MYOMETRIAL INTERFACE; (2) ENHANCED INVASION OF ENDOMETRIUM INTO MYOMETRIUM; (3) METAPLASIA OF STEM CELLS IN MYOMETRIUM; (4) INFILTRATION OF ENDOMETRIAL CELLS IN RETROGRADE MENSTRUAL EFFLUENT INTO THE UTERINE WALL FROM THE SEROSAL SIDE; (5) INDUCTION OF ADENOMYOTIC LESIONS BY ABERRANT LOCAL STEROID AND PITUITARY HORMONES; AND (6) ABNORMAL UTERINE DEVELOPMENT IN RESPONSE TO GENETIC AND EPIGENETIC MODIFICATIONS. DYSMENORRHEA, HMB, AND INFERTILITY ARE LIKELY RESULTS OF INFLAMMATION, NEUROGENESIS, ANGIOGENESIS, AND CONTRACTILE ABNORMALITIES IN THE ENDOMETRIAL AND MYOMETRIAL COMPONENTS. ELUCIDATING MECHANISMS UNDERLYING THE PATHOGENESIS OF ADENOMYOSIS RAISE POSSIBILITIES TO DEVELOP TARGETED THERAPIES TO AMELIORATE SYMPTOMS BEYOND THE CURRENT AGENTS THAT ARE LARGELY INEFFECTIVE. HEREIN, WE ADDRESS THESE POSSIBLE ETIOLOGIES AND DATA THAT SUPPORT UNDERLYING MECHANISMS. 2020 7 3789 28 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 8 1053 34 CLINICAL IMPLICATIONS OF INTERFERON-GAMMA GENETIC AND EPIGENETIC VARIANTS. INTERFERON-GAMMA (IFN-GAMMA) IS AN INTEGRAL AND CRITICAL MOLECULE OF THE IMMUNE SYSTEM, WITH MULTIPLE FUNCTIONS, MOSTLY RELATED TO THE T HELPER TYPE 1 (TH1) RESPONSE TO INFECTION. IT IS CRITICAL FOR DEFENCE AGAINST MYCOBACTERIAL INFECTION AND IS OF INCREASING INTEREST IN DEFENCE AGAINST FUNGI. IN THIS ARTICLE, WE REVIEW THE GENETIC AND EPIGENETIC VARIANTS AFFECTING IFN-GAMMA EXPRESSION AND INVESTIGATE ITS ROLE IN DISEASE, WITH AN EMPHASIS ON FUNGAL DISEASES SUCH AS INVASIVE AND CHRONIC PULMONARY ASPERGILLOSIS. OVER 347 IFN-GAMMA GENE VARIANTS HAVE BEEN DESCRIBED, IN MULTIPLE ETHNIC POPULATIONS. MANY APPEAR TO CONFER A SUSCEPTIBILITY TO DISEASE, ESPECIALLY TUBERCULOSIS (TB) AND HEPATITIS, BUT ALSO SOME NON-INFECTIOUS CONDITIONS SUCH AS APLASTIC ANAEMIA, CERVICAL CANCER AND PSORIASIS. SEVERAL EPIGENETIC MODIFICATIONS ARE ALSO DESCRIBED, INCREASING IFN-GAMMA EXPRESSION IN TH1 LYMPHOCYTES AND REDUCING IFN-GAMMA EXPRESSION IN TH2 LYMPHOCYTES. RECOMBINANT IFN-GAMMA ADMINISTRATION IS LICENSED FOR THE PROPHYLAXIS OF INFECTION (BACTERIAL AND FUNGAL) IN PATIENTS WITH THE PHAGOCYTE FUNCTIONAL DEFICIENCY SYNDROME CHRONIC GRANULOMATOUS DISEASE, ALTHOUGH THE BENEFITS APPEAR LIMITED. INTERFERON-GAMMA THERAPY IS GIVEN TO PATIENTS WITH PROFOUND DEFECTS IN IFN-GAMMA AND INTERLEUKIN-12 PRODUCTION AND APPEARS TO BE BENEFICIAL FOR PATIENTS WITH INVASIVE ASPERGILLOSIS AND CRYPTOCOCCAL MENINGITIS, BUT THE STUDIES ARE NOT DEFINITIVE. A HIGH PROPORTION OF PATIENTS WITH CHRONIC PULMONARY ASPERGILLOSIS ARE POOR PRODUCERS OF IFN-GAMMA IN RESPONSE TO MULTIPLE STIMULI AND COULD ALSO BENEFIT FROM IFN-GAMMA ADMINISTRATION. THE INVESTIGATION AND MANAGEMENT OF PATIENTS WITH POSSIBLE OR DEMONSTRATED IFN-GAMMA DEFICIENCY IN ADULTHOOD IS POORLY STUDIED AND COULD BE GREATLY ENHANCED WITH THE INTEGRATION OF GENETIC DATA. 2014 9 5902 43 T-HELPER 17 CELL POLARIZATION IN PULMONARY ARTERIAL HYPERTENSION. BACKGROUND: INFLAMMATION MAY CONTRIBUTE TO THE PATHOBIOLOGY OF PULMONARY ARTERIAL HYPERTENSION (PAH). DECIPHERING THE PAH FINGERPRINT ON THE INFLAMMATION ORCHESTRATED BY DENDRITIC CELLS (DCS) AND T CELLS, KEY DRIVER AND EFFECTOR CELLS, RESPECTIVELY, OF THE IMMUNE SYSTEM, MAY ALLOW THE IDENTIFICATION OF IMMUNOPATHOLOGIC APPROACHES TO PAH MANAGEMENT. METHODS: USING FLOW CYTOMETRY, WE PERFORMED IMMUNOPHENOTYPING OF MONOCYTE-DERIVED DCS (MODCS) AND CIRCULATING LYMPHOCYTES FROM PATIENTS WITH IDIOPATHIC PAH AND CONTROL SUBJECTS. WITH THE SAME TECHNIQUE, WE PERFORMED CYTOKINE PROFILING OF BOTH POPULATIONS FOLLOWING STIMULATION, COCULTURE, OR BOTH. WE TESTED THE IMMUNOMODULATORY EFFECTS OF A GLUCOCORTICOID (DEXAMETHASONE [DEX]) ON THIS IMMUNOPHENOTYPE AND CYTOKINE PROFILE. USING AN EPIGENETIC APPROACH, WE CONFIRMED THE IMMUNE POLARIZATION IN BLOOD DNA OF PATIENTS WITH PAH. RESULTS: THE PROFILE OF MEMBRANE COSTIMULATORY MOLECULES OF PAH MODCS WAS SIMILAR TO THAT OF CONTROL SUBJECTS. HOWEVER, PAH MODCS RETAINED HIGHER LEVELS OF THE T-CELL ACTIVATING MOLECULES CD86 AND CD40 AFTER DEX PRETREATMENT THAN DID CONTROL MODCS. THIS WAS ASSOCIATED WITH AN INCREASED EXPRESSION OF IL-12P40 AND A REDUCED MIGRATION TOWARD CHEMOKINE (C-C MOTIF) LIGAND 21. MOREOVER, BOTH WITH AND WITHOUT DEX, PAH MODCS INDUCED A HIGHER ACTIVATION AND PROLIFERATION OF CD4+ T CELLS, ASSOCIATED WITH A REDUCED EXPRESSION OF IL-4 (T HELPER 2 RESPONSE) AND A HIGHER EXPRESSION OF IL-17 (T HELPER 17 RESPONSE). PURIFIED PAH CD4+ T CELLS EXPRESSED A HIGHER LEVEL OF IL-17 AFTER ACTIVATION THAN DID THOSE OF CONTROL SUBJECTS. LASTLY, THERE WAS SIGNIFICANT HYPOMETHYLATION OF THE IL-17 PROMOTER IN THE PAH BLOOD DNA AS COMPARED WITH THE CONTROL BLOOD. CONCLUSIONS: WE HAVE HIGHLIGHTED T HELPER 17 CELL IMMUNE POLARIZATION IN PATIENTS WITH PAH, AS HAS BEEN PREVIOUSLY DEMONSTRATED IN OTHER CHRONIC INFLAMMATORY AND AUTOIMMUNE CONDITIONS. 2015 10 5602 28 RORGAMMAT(+) HEMATOPOIETIC CELLS ARE NECESSARY FOR TUMOR CELL PROLIFERATION DURING COLITIS-ASSOCIATED TUMORIGENESIS IN MICE. COLORECTAL CANCER (CRC) IS ONE OF THE MOST COMMON TUMOR ENTITIES. IN PATIENTS WITH INFLAMMATORY BOWEL DISEASES, THE DEVELOPMENT OF COLITIS-ASSOCIATED COLON CANCER IS CONSIDERED A DANGEROUS LONG-TERM COMPLICATION. IL-17A AND THE TRANSCRIPTION FACTOR RETINOIC ACID RECEPTOR-RELATED ORPHAN RECEPTOR GAMMAT (RORGAMMAT) PLAY FUNDAMENTAL ROLES IN THE PATHOGENESIS OF INFLAMMATORY BOWEL DISEASES; IN HUMAN STUDIES, WE DETECTED A DENSE INFILTRATION OF RORGAMMAT-DEPENDENT CD4(+) IL17A(+) T HELPER (TH)17 CELLS IN SPECIMENS OF CRC, ULCERATIVE COLITIS, AND ULCERATIVE COLITIS-ASSOCIATED COLORECTAL CANCER. HOWEVER, THE MECHANISTIC ROLE OF RORGAMMAT(+) HEMATOPOIETIC CELLS IN COLITIS-ASSOCIATED TUMORIGENESIS REMAINS UNCLEAR. TO INVESTIGATE COLITIS-ASSOCIATED COLON TUMORIGENESIS, WE CONDUCTED STUDIES IN THE AOM+DSS MOUSE MODEL THAT REVEALED THE IMPORTANCE OF RORGAMMAT FOR COLON TUMOR PROGRESSION. IN THE ABSENCE OF RORGAMMAT-DEPENDENT TH17 LYMPHOCYTES, MICE SHOWED SIGNS OF INTENSE CHRONIC COLITIS, BUT DEVELOPED SIGNIFICANTLY FEWER MACROSCOPIC TUMOR NODULES. THE REDUCTION OF TUMOR DEVELOPMENT IN RORGAMMAT(-/-) MICE WAS NOT DUE TO REDUCED COLON TUMOR INITIATION. HOWEVER, THE PROLIFERATION RATE OF TUMOR CELLS WAS REDUCED IN THE ABSENCE OF RORGAMMAT-DEPENDENT TH17 CELLS AND TUMOR CELLS SHOWED PRONOUNCED SIGNS OF SENESCENCE-ASSOCIATED EPIGENETIC AND LYSOSOMAL CHANGES. THESE RESULTS INDICATE AN IMPORTANT ROLE FOR THE IMMUNOLOGICAL MILIEU IN COLITIS-ASSOCIATED CANCER, WHICH IS SHAPED IN-PART BY RORGAMMAT-DEPENDENT TH17 LYMPHOCYTES THAT SUPPORT CRC GROWTH. 2015 11 6009 32 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 12 2275 43 EPIGENETIC REGULATION AND T-CELL RESPONSES IN ENDOMETRIOSIS - SOMETHING OTHER THAN AUTOIMMUNITY. ENDOMETRIOSIS IS DEFINED AS THE PRESENCE OF ENDOMETRIAL-LIKE GLANDS AND STROMA LOCATED OUTSIDE THE UTERINE CAVITY. THIS COMMON, ESTROGEN DEPENDENT, INFLAMMATORY CONDITION AFFECTS UP TO 15% OF REPRODUCTIVE-AGED WOMEN AND IS A WELL-RECOGNIZED CAUSE OF CHRONIC PELVIC PAIN AND INFERTILITY. DESPITE THE STILL UNKNOWN ETIOLOGY OF ENDOMETRIOSIS, MUCH EVIDENCE SUGGESTS THE PARTICIPATION OF EPIGENETIC MECHANISMS IN THE DISEASE ETIOPATHOGENESIS. THE MAIN RATIONALE IS BASED ON THE FACT THAT HERITABLE PHENOTYPE CHANGES THAT DO NOT INVOLVE ALTERATIONS IN THE DNA SEQUENCE ARE COMMON TRIGGERS FOR HORMONAL, IMMUNOLOGICAL, AND INFLAMMATORY DISORDERS, WHICH PLAY A KEY ROLE IN THE FORMATION OF ENDOMETRIOTIC FOCI. EPIGENETIC MECHANISMS REGULATING T-CELL RESPONSES, INCLUDING DNA METHYLATION AND POSTTRANSLATIONAL HISTONE MODIFICATIONS, DESERVE ATTENTION BECAUSE TISSUE-RESIDENT T LYMPHOCYTES WORK IN CONCERT WITH ORGAN STRUCTURAL CELLS TO GENERATE APPROPRIATE IMMUNE RESPONSES AND ARE FUNCTIONALLY SHAPED BY ORGAN-SPECIFIC ENVIRONMENTAL CONDITIONS. THUS, A FAILURE TO PRECISELY REGULATE IMMUNE CELL TRANSCRIPTION MAY RESULT IN COMPROMISED IMMUNOLOGICAL INTEGRITY OF THE ORGAN WITH AN INCREASED RISK OF INFLAMMATORY DISORDERS. THE COEXISTENCE OF ENDOMETRIOSIS AND AUTOIMMUNITY IS A WELL-KNOWN OCCURRENCE. RECENT RESEARCH RESULTS INDICATE REGULATORY T-CELL (TREG) ALTERATIONS IN ENDOMETRIOSIS, AND AN INCREASED NUMBER OF HIGHLY ACTIVE TREGS AND MACROPHAGES HAVE BEEN FOUND IN PERITONEAL FLUID FROM WOMEN WITH ENDOMETRIOSIS. ELIMINATION OF THE REGULATORY FUNCTION OF T CELLS AND AN IMBALANCE BETWEEN T HELPER CELLS OF THE TH1 AND TH2 TYPES HAVE BEEN REPORTED IN THE ENDOMETRIA OF WOMEN WITH ENDOMETRIOSIS-ASSOCIATED INFERTILITY. THIS REVIEW AIMS TO PRESENT THE STATE OF THE ART IN RECOGNITION EPIGENETIC REPROGRAMMING OF T CELLS AS THE KEY FACTOR IN THE PATHOPHYSIOLOGY OF ENDOMETRIOSIS IN THE CONTEXT OF T-CELL-RELATED AUTOIMMUNITY. THE NEW POTENTIAL THERAPEUTIC APPROACHES BASED ON EPIGENETIC MODULATION AND/OR ADOPTIVE TRANSFER OF T CELLS WILL ALSO BE OUTLINED. 2022 13 4950 24 PATHOGENESIS OF ADENOMYOSIS: AN UPDATE ON MOLECULAR MECHANISMS. ADENOMYOSIS IS A UTERINE DISORDER BECOMING MORE COMMONLY DIAGNOSED IN WOMEN OF REPRODUCTIVE AGE BECAUSE OF DIAGNOSTIC IMAGING ADVANCEMENTS. THE NEW EPIDEMIOLOGICAL SCENARIO AND THE CLINICAL EVIDENCE OF PELVIC PAIN, ABNORMAL UTERINE BLEEDING AND INFERTILITY ARE CHANGING THE CLASSIC PERSPECTIVE OF ADENOMYOSIS AS A PREMENOPAUSAL DISEASE. IN THE LAST DECADE, THE EVALUATION OF MULTIPLE MOLECULAR MEDIATORS HAS IMPROVED OUR KNOWLEDGE OF PATHOGENIC MECHANISMS OF ADENOMYOSIS, SUPPORTING THAT THIS IS AN INDEPENDENT DISEASE FROM ENDOMETRIOSIS. ALTHOUGH THEY SHARE COMMON GENETIC MUTATIONS AND EPIGENETIC CHANGES IN SEX STEROID HORMONE RECEPTORS AND SIMILAR INFLAMMATORY MEDIATORS, AN INCREASING NUMBER OF RECENT STUDIES HAVE SHOWN PATHOGENIC PATHWAYS SPECIFIC FOR ADENOMYOSIS. A PUBMED SEARCH UP TO OCTOBER 2016 SUMMARIZES THE KEY MEDIATORS OF PAIN, ABNORMAL UTERINE BLEEDING AND INFERTILITY IN ADENOMYOSIS, INCLUDING SEX STEROID HORMONE RECEPTORS, INFLAMMATORY MOLECULES, EXTRACELLULAR MATRIX ENZYMES, GROWTH FACTORS AND NEUROANGIOGENIC FACTORS. 2017 14 4964 26 PATHOGENETIC AND CLINICAL ASPECTS OF ANTI-NEUTROPHIL CYTOPLASMIC AUTOANTIBODY-ASSOCIATED VASCULITIDES. ANTI-NEUTROPHIL CYTOPLASMIC AUTOANTIBODIES (ANCA) TARGETING PROTEINASE 3 (PR3) AND MYELOPEROXIDASE EXPRESSED BY INNATE IMMUNE CELLS (NEUTROPHILS AND MONOCYTES) ARE SALIENT DIAGNOSTIC AND PATHOGENIC FEATURES OF SMALL VESSEL VASCULITIS, COMPRISING GRANULOMATOSIS WITH POLYANGIITIS (GPA), MICROSCOPIC POLYANGIITIS, AND EOSINOPHILIC GPA. GENETIC STUDIES SUGGEST THAT ANCA-ASSOCIATED VASCULITIDES (AAV) CONSTITUTE SEPARATE DISEASES, WHICH SHARE COMMON IMMUNOLOGICAL AND PATHOLOGICAL FEATURES, BUT ARE OTHERWISE HETEROGENEOUS. THE SUCCESSFUL THERAPEUTIC USE OF ANTI-CD20 ANTIBODIES EMPHASIZES THE PROMINENT ROLE OF ANCA AND POSSIBLY OTHER AUTOANTIBODIES IN THE PATHOGENESIS OF AAV. HOWEVER, TO ELUCIDATE CAUSAL EFFECTS IN AAV, A BETTER UNDERSTANDING OF THE COMPLEX INTERPLAY LEADING TO THE EMERGENCE OF B LYMPHOCYTES THAT PRODUCE PATHOGENIC ANCA REMAINS A CHALLENGE. DIFFERENT SCENARIOS SEEM POSSIBLE; E.G., THE BREAK OF TOLERANCE INDUCED BY A SHIFT FROM NON-PATHOGENIC TOWARD PATHOGENIC AUTOANTIGEN EPITOPES IN INFLAMED TISSUE. THIS REVIEW GIVES A BRIEF OVERVIEW ON CURRENT KNOWLEDGE ABOUT GENETIC AND EPIGENETIC FACTORS, BARRIER DYSFUNCTION AND CHRONIC NON-RESOLVING INFLAMMATION, NECRO-INFLAMMATORY AUTO-AMPLIFICATION OF CELLULAR DEATH AND INFLAMMATION, ALTERED AUTOANTIGEN PRESENTATION, ALTERNATIVE COMPLEMENT PATHWAY ACTIVATION, ALTERATIONS WITHIN PERIPHERAL AND INFLAMED TISSUE-RESIDING T- AND B-CELL POPULATIONS, ECTOPIC LYMPHOID TISSUE NEOFORMATION, THE CHARACTERIZATION OF PR3-SPECIFIC T-CELLS, PROPERTIES OF ANCA, LINKS BETWEEN AUTOIMMUNE DISEASE AND INFECTION-TRIGGERED PATHOLOGY, AND ANIMAL MODELS IN AAV. 2018 15 3645 29 INCREASED PRESENCE AND DIFFERENTIAL MOLECULAR IMPRINTING OF TRANSIT AMPLIFYING CELLS IN PSORIASIS. PSORIASIS IS A VERY COMMON CHRONIC INFLAMMATORY SKIN DISEASE CHARACTERIZED BY EPIDERMAL THICKENING AND SCALING RESULTING FROM KERATINOCYTE HYPERPROLIFERATION AND IMPAIRED DIFFERENTIATION. PATHOMECHANISTIC STUDIES IN PSORIASIS ARE OFTEN LIMITED BY USING WHOLE SKIN TISSUE BIOPSIES, NEGLECTING THEIR STRATIFICATION AND CELLULAR DIVERSITY. THIS STUDY AIMED AT CHARACTERIZING EPIDERMAL ALTERATIONS IN PSORIASIS AT THE LEVEL OF KERATINOCYTE POPULATIONS. EPIDERMAL CELL POPULATIONS WERE PURIFIED FROM SKIN BIOPSIES OF PSORIASIS PATIENTS AND HEALTHY DONORS USING A NOVEL CELL TYPE-SPECIFIC APPROACH. MOLECULAR CHARACTERIZATION OF THE TRANSIT-AMPLIFYING CELLS (TAC), THE KEY PLAYERS OF EPIDERMAL RENEWAL, WAS PERFORMED USING IMMUNOCYTOFLUORESCENCE-TECHNIQUE AND INTEGRATED MULTISCALE-OMICS ANALYSES. ALREADY TAC FROM NON-LESIONAL PSORIATIC SKIN SHOWED ALTERED METHYLATION AND DIFFERENTIAL EXPRESSION IN 1.7% AND 1.0% OF ALL PROTEIN-CODING GENES, RESPECTIVELY. IN PSORIATIC LESIONS, TAC WERE STRONGLY EXPANDED SHOWING FURTHER INCREASED DIFFERENTIALLY METHYLATED (10-FOLD) AND EXPRESSED (22-FOLD) GENES NUMBERS. IMPORTANTLY, 17.2% OF DIFFERENTIALLY EXPRESSED GENES WERE ASSOCIATED WITH RESPECTIVE GENE METHYLATIONS. COMPARED WITH NON-LESIONAL TAC, PATHWAY ANALYSES REVEALED METABOLIC ALTERATIONS AS ONE FEATURE PREDOMINANTLY CHANGED IN TAC DERIVED FROM ACTIVE PSORIATIC LESIONS. OVERALL, OUR STUDY SHOWED STAGE-SPECIFIC MOLECULAR ALTERATIONS, ALLOWS NEW INSIGHTS INTO THE PATHOGENESIS, AND IMPLIES THE INVOLVEMENT OF EPIGENETIC MECHANISMS IN LESION DEVELOPMENT IN PSORIASIS. KEY MESSAGES: TRANSIT AMPLIFYING CELL (TAC) NUMBERS ARE HIGHLY INCREASED IN PSORIATIC LESIONS PSORIATIC TAC SHOW PROFOUND MOLECULAR ALTERATIONS & STAGE-SPECIFIC IDENTITY TAC FROM UNAFFECTED AREAS ALREADY SHOW FIRST SIGNS OF MOLECULAR ALTERATIONS LESIONAL TAC SHOW A PREFERENCE IN METABOLIC-RELATED ALTERATIONS. 2020 16 1061 45 CLINICAL REMISSION OF SIGHT-THREATENING NON-INFECTIOUS UVEITIS IS CHARACTERIZED BY AN UPREGULATION OF PERIPHERAL T-REGULATORY CELL POLARIZED TOWARDS T-BET AND TIGIT. BACKGROUND: NON-INFECTIOUS UVEITIS CAN CAUSE CHRONIC RELAPSING AND REMITTING OCULAR INFLAMMATION, WHICH MAY REQUIRE HIGH DOSE SYSTEMIC IMMUNOSUPPRESSION TO PREVENT SEVERE SIGHT LOSS. IT HAS BEEN CLASSICALLY DESCRIBED AS AN AUTOIMMUNE DISEASE, MEDIATED BY PRO-INFLAMMATORY TH1 AND TH17 T-CELL SUBSETS. STUDIES SUGGEST THAT NATURAL IMMUNOSUPPRESSIVE CD4(+)CD25(+)FOXP3(+) T-REGULATORY CELLS (TREGS) ARE INVOLVED IN RESOLUTION OF INFLAMMATION AND MAY BE INVOLVED IN THE MAINTENANCE OF CLINICAL REMISSION. OBJECTIVE: TO INVESTIGATE WHETHER THERE IS A PERIPHERAL BLOOD IMMUNOREGULATORY PHENOTYPE ASSOCIATED WITH CLINICAL REMISSION OF SIGHT-THREATENING NON-INFECTIOUS UVEITIS BY COMPARING PERIPHERAL BLOOD LEVELS OF TREG, TH1, AND TH17, AND ASSOCIATED DNA METHYLATION AND CYTOKINE LEVELS IN PATIENTS WITH ACTIVE UVEITIC DISEASE, CONTROL SUBJECTS AND PATIENTS (WITH PREVIOUSLY ACTIVE DISEASE) IN CLINICAL REMISSION INDUCED BY IMMUNOSUPPRESSIVE DRUGS. METHODS: ISOLATED PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMC) FROM PERIPHERAL BLOOD SAMPLES FROM PROSPECTIVELY RECRUITED SUBJECTS WERE ANALYZED BY FLOW CYTOMETRY FOR CD3, CD4, FOXP3, TIGIT, T-BET, AND RELATED ORPHAN RECEPTOR GAMMAT. EPIGENETIC DNA METHYLATION LEVELS OF FOXP3 TREG-SPECIFIC DEMETHYLATED REGION (TSDR), FOXP3 PROMOTER, TBX21, RORC2, AND TIGIT LOCI WERE DETERMINED IN CRYOPRESERVED PBMC USING A NEXT-GENERATION SEQUENCING APPROACH. RELATED CYTOKINES WERE MEASURED IN BLOOD SERA. FUNCTIONAL SUPPRESSIVE CAPACITY OF TREG WAS ASSESSED USING T-CELL PROLIFERATION ASSAYS. RESULTS: FIFTY PATIENTS WITH UVEITIS (INTERMEDIATE, POSTERIOR, AND PANUVEITIS) AND 10 CONTROL SUBJECTS WERE RECRUITED. THE FREQUENCY OF CD4(+)CD25(+)FOXP3(+) TREG, TIGIT(+) TREG, AND T-BET(+) TREG AND THE RATIO OF TREG TO TH1 WERE SIGNIFICANTLY HIGHER IN REMISSION PATIENTS COMPARED WITH PATIENTS WITH ACTIVE UVEITIC DISEASE; AND TIGIT(+) TREGS WERE A SIGNIFICANT PREDICTOR OF CLINICAL REMISSION. TREG FROM PATIENTS IN CLINICAL REMISSION DEMONSTRATED A HIGH LEVEL OF IN VITRO SUPPRESSIVE FUNCTION COMPARED WITH TREG FROM CONTROL SUBJECTS AND FROM PATIENTS WITH UNTREATED ACTIVE DISEASE. PBMC FROM PATIENTS IN CLINICAL REMISSION HAD SIGNIFICANTLY LOWER METHYLATION LEVELS AT THE FOXP3 TSDR, FOXP3 PROMOTER, AND TIGIT LOCI AND HIGHER LEVELS AT RORC LOCI THAN THOSE WITH ACTIVE DISEASE. CLINICAL REMISSION WAS ALSO ASSOCIATED WITH SIGNIFICANTLY HIGHER SERUM LEVELS OF TRANSFORMING GROWTH FACTOR BETA AND IL-10, WHICH POSITIVELY CORRELATED WITH TREG LEVELS, AND LOWER SERUM LEVELS OF IFNGAMMA, IL-17A, AND IL-22 COMPARED WITH PATIENTS WITH ACTIVE DISEASE. CONCLUSION: CLINICAL REMISSION OF SIGHT-THREATENING NON-INFECTIOUS UVEITIS HAS AN IMMUNOREGULATORY PHENOTYPE CHARACTERIZED BY UPREGULATION OF PERIPHERAL TREG, POLARIZED TOWARD T-BET AND TIGIT. THESE FINDINGS MAY ASSIST WITH INDIVIDUALIZED THERAPY OF UVEITIS, BY INFORMING WHETHER DRUG THERAPY HAS INDUCED PHENOTYPICALLY STABLE TREG ASSOCIATED WITH LONG-TERM CLINICAL REMISSION. 2018 17 991 34 CHRONIC STIMULATION DRIVES HUMAN NK CELL DYSFUNCTION AND EPIGENETIC REPROGRAMING. A POPULATION OF NATURAL KILLER (NK) CELLS EXPRESSING THE ACTIVATING RECEPTOR NKG2C AND THE MATURATION MARKER CD57 EXPANDS IN RESPONSE TO HUMAN CYTOMEGALOVIRUS (HCMV) INFECTION. CD3-CD56DIMCD57+NKG2C+ NK CELLS ARE SIMILAR TO CD8+ MEMORY T CELLS WITH RAPID AND ROBUST EFFECTOR FUNCTION UPON RE-STIMULATION, PERSISTENCE, AND EPIGENETIC REMODELING OF THE IFNG LOCUS. CHRONIC ANTIGEN STIMULATION DRIVES CD8+ MEMORY T CELL PROLIFERATION WHILE ALSO INDUCING GENOME-WIDE EPIGENETIC REPROGRAMING AND DYSFUNCTION. WE HYPOTHESIZED THAT CHRONIC STIMULATION COULD SIMILARLY INDUCE EPIGENETIC REPROGRAMING AND DYSFUNCTION IN NK CELLS. HERE WE SHOW THAT CHRONIC STIMULATION OF ADAPTIVE NK CELLS THROUGH NKG2C USING PLATE-BOUND AGONISTIC ANTIBODIES IN COMBINATION WITH IL-15 DROVE ROBUST PROLIFERATION AND ACTIVATION OF CD3-CD56DIMCD57+NKG2C+ NK CELLS WHILE SIMULTANEOUSLY INDUCING HIGH EXPRESSION OF THE CHECKPOINT INHIBITORY RECEPTORS LAG-3 AND PD-1. MARKED INDUCTION OF CHECKPOINT INHIBITORY RECEPTORS WAS ALSO OBSERVED ON THE SURFACE OF ADAPTIVE NK CELLS CO-CULTURED WITH HCMV-INFECTED ENDOTHELIAL CELLS. CHRONICALLY STIMULATED ADAPTIVE NK CELLS WERE DYSFUNCTIONAL WHEN CHALLENGED WITH TUMOR TARGETS. THESE CELLS EXHIBITED A PATTERN OF EPIGENETIC REPROGRAMING, WITH GENOME-WIDE ALTERATIONS IN DNA METHYLATION. OUR STUDY HAS IMPORTANT IMPLICATIONS FOR CANCER IMMUNOTHERAPY AND SUGGEST THAT EXHAUSTED NK CELLS COULD BE TARGETED WITH INHIBITORY CHECKPOINT RECEPTOR BLOCKADE. 2019 18 6293 29 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 19 5912 32 TARGETED THERAPIES IN SYSTEMIC LUPUS ERYTHEMATOSUS. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC, MULTISYSTEM DISORDER CHARACTERISED BY LOSS OF TOLERANCE TO ENDOGENOUS NUCLEAR ANTIGENS AND AUTOANTIBODY FORMATION. RECENT INSIGHT INTO THE IMMUNOPATHOGENESIS OF LUPUS HAS PROVIDED THE FOUNDATION FOR A NOVEL CLASS OF AGENTS WHICH TARGET SPECIFIC, DYSREGULATED COMPONENTS OF THE IMMUNE SYSTEM. EFFORTS HAVE FOCUSED PREDOMINANTLY ON B-CELL DEPLETING THERAPIES, OF WHICH BELIMUMAB WAS THE FIRST TO DEMONSTRATE SUCCESS IN PHASE III STUDIES AND THUS RECEIVE MARKETING AUTHORISATION. OFF-LABEL PRESCRIBING OF RITUXIMAB IN REFRACTORY CASES IS COMMON AND SUPPORTED BY UNCONTROLLED STUDIES, WHICH SUGGEST A FAVOURABLE RISK:BENEFIT PROFILE. HOWEVER, TWO PLACEBO-CONTROLLED TRIALS FAILED TO SHOW BENEFIT, POSSIBLY BECAUSE OF INAPPROPRIATE PATIENT SELECTION AND OTHER ASPECTS OF TRIAL METHODOLOGY. INHIBITION OF DYSREGULATED CO-STIMULATORY SIGNALS AND CYTOKINES ARE OTHER THERAPEUTIC STRATEGIES CURRENTLY UNDER INVESTIGATION. SOME CANDIDATE DRUGS FAILED TO MEET PRIMARY ENDPOINTS IN EARLY-PHASE CLINICAL TRIALS, YET DEMONSTRATED CLINICAL BENEFIT WHEN ALTERNATIVE ASSESSMENT CRITERIA WERE APPLIED OR SPECIFIC PATIENT SUB-GROUPS ANALYSED. WELL-DESIGNED STUDIES OF GREATER SIZE AND DURATION ARE NEEDED TO CLARIFY THE THERAPEUTIC UTILITY OF THESE AGENTS. FUTURE IMMUNOMODULATORY STRATEGIES TARGETING INTERFERON-ALPHA, T CELLS, OXIDATIVE STRESS AND EPIGENETIC ABNORMALITIES MAY REDUCE MULTISYSTEM DISEASE ACTIVITY AND PROLONG SURVIVAL IN THIS COMPLEX AND HETEROGENEIC DISEASE. 2013 20 2793 21 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