1 4964 142 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 2 1033 29 CITRULLINATION OF AUTOANTIGENS IMPLICATES NETOSIS IN THE INDUCTION OF AUTOIMMUNITY. TOLERANCE BLOCKS THE EXPRESSION OF AUTOANTIBODIES, WHEREAS AUTOIMMUNITY PROMOTES IT. HOW TOLERANCE BREAKS AND AUTOANTIBODY PRODUCTION BEGINS THUS ARE CRUCIAL QUESTIONS FOR UNDERSTANDING AND TREATMENT OF AUTOIMMUNE DISEASES. EVIDENCE IMPLICATES CELL DEATH AND AUTOANTIGEN MODIFICATIONS IN THE INITIATION OF AUTOIMMUNE REACTIONS. ONE FORM OF NEUTROPHIL CELL DEATH CALLED NETOSIS DESERVES ATTENTION BECAUSE IT REQUIRES THE POST-TRANSLATIONAL MODIFICATION OF HISTONES AND RESULTS IN THE EXTRACELLULAR RELEASE OF CHROMATIN. NETOSIS RECEIVED ITS NAME FROM NET, THE ACRONYM GIVEN TO NEUTROPHIL EXTRACELLULAR TRAP. THE EXTRACELLULAR CHROMATIN INCORPORATES HISTONES IN WHICH ARGININES HAVE BEEN CONVERTED TO CITRULLINES BY PEPTIDYLARGININE DEIMINASE IV (PAD4). THE DEIMINATED CHROMATIN MAY FUNCTION TO CAPTURE OR 'TRAP' BACTERIAL PATHOGENS, THUS GENERATING AN EXTRACELLULAR COMPLEX OF DEIMINATED HISTONES AND BACTERIAL CELL ADJUVANTS. THE COMPLEX OF BACTERIAL ANTIGENS AND DEIMINATED CHROMATIN MAY BE INTERNALISED BY HOST PHAGOCYTES DURING ACUTE INFLAMMATORY CONDITIONS, AS ARISE DURING BACTERIAL INFECTIONS OR CHRONIC AUTOINFLAMMATORY DISORDERS. THE UPTAKE AND PROCESSING OF DEIMINATED CHROMATIN TOGETHER WITH BACTERIAL ADJUVANTS BY PHAGOCYTES MAY INDUCE THE PRESENTATION OF MODIFIED HISTONE EPITOPES AND CO-STIMULATION, THUS YIELDING A POWERFUL STIMULUS TO BREAK TOLERANCE. AUTOANTIBODIES TO DEIMINATED HISTONES ARE PREVALENT IN FELTY'S SYNDROME PATIENTS AND ARE PRESENT IN SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) AND PATIENTS WITH RHEUMATOID ARTHRITIS (RA). THESE OBSERVATIONS CLEARLY IMPLICATE HISTONE DEIMINATION AS AN EPIGENETIC MARK THAT CAN ACT AS AN AUTOANTIBODY STIMULANT. 2014 3 3025 41 GENETICS AND PATHOPHYSIOLOGY OF GRANULOMATOSIS WITH POLYANGIITIS (GPA) AND ITS MAIN AUTOANTIGEN PROTEINASE 3. GRANULOMATOSIS WITH POLYANGIITIS (GPA) IS A SEVERE AUTOIMMUNE DISEASE AND ONE OF THE SMALL VESSEL ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY (ANCA)-ASSOCIATED VASCULITIDES. ALTHOUGH ITS ETIOLOGY AND PATHOPHYSIOLOGY ARE STILL WIDELY UNKNOWN, IT IS ACCEPTED THAT INFECTIONS, ENVIRONMENTAL FACTORS, EPIGENETIC MODIFICATIONS, AND A GENETIC PREDISPOSITION PROVIDE THE BASIS FOR THIS SYSTEMIC DISORDER. GPA TYPICALLY EVOLVES INTO TWO PHASES: AN INITIAL PHASE CHARACTERIZED BY EAR, NOSE AND THROAT (ENT) MANIFESTATIONS, SUCH AS CHRONIC SINUSITIS AND OTITIS, ULCERATION OF THE ORAL CAVITY AND PHARYNX, AS WELL AS PULMONARY NODULES AND A SEVERE GENERALIZED PHASE, DEFINED BY THE OCCURRENCE OF RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS, PULMONARY HEMORRHAGE, AND ARTHRITIS. ANCAS, DIRECTED AGAINST THE NEUTROPHILIC ENZYMES PROTEINASE 3 AND MYELOPEROXIDASE, ARE PRESENT IN UP TO 90% OF THE AFFECTED PATIENTS IN THE SYSTEMIC PHASE. AS THE HUMORAL IMMUNITY IS PREDOMINANTLY DIRECTED AGAINST NEUTROPHILIC ANTIGENS, IT IS APPARENT THAT NEUTROPHILS PLAY A CRITICAL ROLE IN GPA BOTH AS TARGET AND EFFECTOR CELLS. ALTHOUGH GPA PATHOGENESIS IS NOT WELL KNOWN, SOME SUSCEPTIBILITY GENES AND LOCI HAVE BEEN IDENTIFIED BY CANDIDATE GENE APPROACHES, GENOME-WIDE ASSOCIATION STUDIES, AND META-ANALYSES, AS WELL AS FAMILIAL ASSOCIATION STUDIES. SUCH GENES ARE CTLA4, PTPN22, COL11A2, SERPINA1, AND THE MHC CLASS II GENE CLUSTER. THIS REVIEW HIGHLIGHTS THE CLINICAL, PATHOPHYSIOLOGICAL, AND GENETIC BACKGROUND OF GPA AND AIMS TO GIVE AN OVERVIEW OF RECENT EFFORTS TO IDENTIFY GPA SUSCEPTIBILITY GENES. WE POINT OUT THE GENETIC BASIS OF THE MAIN AUTOANTIGEN PR3 AND WHY IT IS SO DIFFICULT TO ESTABLISH A MURINE GPA MODEL. 2016 4 3406 34 HOW THE IMMUNE SYSTEM RESPONDS TO ALLERGY IMMUNOTHERAPY. IGE-MEDIATED DISEASES REPRESENT A HIGHLY DIVERSIFIED AND MULTIFACTORIAL GROUP OF DISORDERS THAT CAN DEEPLY IMPACT THE PATIENTS' QUALITY OF LIFE. CURRENTLY, ALLERGY IMMUNOTHERAPY (AIT) STILL REMAINS THE GOLD STANDARD FOR THE MANAGEMENT OF SUCH PATHOLOGIES. IN THIS REVIEW, WE COMPREHENSIVELY EXAMINE AND DISCUSS HOW AIT CAN AFFECT BOTH THE INNATE AND THE ADAPTIVE IMMUNE RESPONSES AT DIFFERENT CELL LEVELS AND PROPOSE TIMING-SCHEDULED ALTERATIONS INDUCED BY AIT BY HYPOTHESIZING FIVE SEQUENTIAL PHASES: AFTER THE DESENSITIZATION OF EFFECTOR NON-LYMPHOID CELLS AND A TRANSIENT INCREASE OF IGE (PHASE 1), HIGH DOSES OF ALLERGEN GIVEN BY AIT STIMULATE THE SHIFT FROM TYPE 2/TYPE 3 TOWARDS TYPE 1 RESPONSE (PHASE 2), WHICH IS PROGRESSIVELY POTENTIATED BY THE INCREASE OF IFN-GAMMA THAT PROMOTES THE CHRONIC ACTIVATION OF APCS, PROGRESSIVELY LEADING TO THE HYPEREXPRESSION OF NOTCH1L (DELTA4) AND THE SECRETION OF IL-12 AND IL-27, WHICH ARE ESSENTIAL TO ACTIVATE IL-10 GENE IN TH1 AND ILC1 CELLS. AS CONSEQUENCE, AN EXPANSION OF CIRCULATING MEMORY TH1/TR1 CELLS AND ILC-REG CHARACTERIZES THE THIRD PHASE ADDRESSED TO ANTAGONIZE/BALANCE THE EXCESS OF TYPE 1 RESPONSE (PHASE 3). THE PROGRESSIVE INCREASE OF IL-10 TRIGGERS A NUMBER OF REGULATORY CIRCUITS SUSTAINED BY INNATE AND ADAPTIVE IMMUNE CELLS AND FAVORING T-CELL TOLERANCE (PHASE 4), WHICH MAY ALSO BE MAINTAINED FOR A LONG PERIOD AFTER AIT INTERRUPTION (PHASE 5). DIFFERENT ADMINISTRATION APPROACHES OF AIT HAVE SHOWN A SIMILAR TAILORING OF THE IMMUNE RESPONSES AND CAN BE MONITORED BY TIMELY, OPTIMIZED BIOMARKERS. THE CLINICAL FAILURE OF THIS TREATMENT CAN OCCUR, AND MANY GENETIC/EPIGENETIC POLYMORPHISMS/MUTATIONS INVOLVING SEVERAL IMMUNOLOGICAL MECHANISMS, SUCH AS THE PLASTICITY OF IMMUNE RESPONSES AND THE INDUCTION/MAINTENANCE OF REGULATORY CIRCUITS, HAVE BEEN DESCRIBED. THE KNOWLEDGE OF HOW AIT CAN SHAPE THE IMMUNE SYSTEM AND ITS RESPONSES IS A KEY TOOL TO DEVELOP NOVEL AIT STRATEGIES INCLUDING THE ENGINEERING OF ALLERGEN OR THEIR EPITOPES. WE NOW HAVE THE POTENTIAL TO UNDERSTAND THE PRECISE CAUSES OF AIT FAILURE AND TO ESTABLISH THE BEST BIOMARKERS OF AIT EFFICACY IN EACH PHASE OF THE TREATMENT. 2022 5 373 30 AN EMERGING ROLE OF NEUTROPHILS AND NETOSIS IN CHRONIC INFLAMMATION AND FIBROSIS IN SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) AND ANCA-ASSOCIATED VASCULITIDES (AAV): IMPLICATIONS FOR THE PATHOGENESIS AND TREATMENT. NEUTROPHILS DERIVE FROM HEMATOPOIETIC STEM CELLS (HSCS) WITH SYSTEMIC INFLAMMATION DRIVING THEIR ACTIVATION AND DIFFERENTIATION TO MYELOID PROGENITORS TO ENSURE ENHANCED MYELOPOIESIS. EPIGENETIC REPROGRAMING AND RE-EDUCATION OF THESE HSCS PRODUCES NEUTROPHILS PRIMED TOWARDS ELIMINATION OF PATHOGENS AND INCREASED INFLAMMATORY RESPONSE. NEUTROPHILS -AN IMPORTANT COMPONENT OF ACUTE INFLAMMATION- ARE NOT PRESENT IN CHRONIC INFLAMMATORY TISSUES LEADING TO THE FALSE ASSUMPTION THAT THEY MAY NOT BE AS IMPORTANT FOR THE LATTER. ACTIVATED NEUTROPHILS MAY RELEASE NEUTROPHIL EXTRACELLULAR TRAPS (NETS) DURING A DISTINCT FORM OF CELL DEATH, NAMED NETOSIS; NETS ARE RICH IN BIOACTIVE MOLECULES THAT PROMOTE THROMBOSIS (INCLUDING ATHEROTHROMBOSIS), INFLAMMATION AND FIBROSIS. THUS, ALTHOUGH NEUTROPHILS MAY NOT BE PRESENT IN CHRONIC INFLAMMATORY LESIONS, THEIR REMNANTS MAY AMPLIFY THE INFLAMMATORY RESPONSE BEYOND THEIR SHORT LIFE-SPAN IN THE TISSUES. HEREIN, WE REVIEW CURRENT EVIDENCE SUPPORTING A ROLE OF NEUTROPHILS AND NETOSIS IN TISSUE INJURY AND DYSFUNCTION IN SYSTEMIC AUTOIMMUNITY USING AS DISEASE PARADIGMS SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) AND THE ANCA-ASSOCIATED VASCULITIDES (AAV). WE ALSO DISCUSS THE MECHANISMS INVOLVED AND THEIR POTENTIAL AS TARGETS FOR NOVEL THERAPY AND DRUG REPOSITIONING. 2019 6 3564 30 IMPACT OF GENETIC AND ENVIRONMENTAL FACTORS ON AUTOIMMUNE HEPATITIS. AUTOIMMUNE HEPATITIS (AIH) IS A CHRONIC NON-RESOLVING LIVER DISEASE CHARACTERIZED BY DIFFUSE HYPERGAMMAGLOBULINEMIA, THE PRESENCE OF AUTOANTIBODIES AND CHARACTERISTIC HISTOLOGICAL FINDINGS. THE DISEASE CAN HAVE CATASTROPHIC OUTCOME WITH THE DEVELOPMENT OF END-STAGE LIVER DISEASE IF MISDIAGNOSED/UNDIAGNOSED AND LEFT UNTREATED. AIH PATHOGENESIS REMAINS OBSCURE AND THE MAIN HYPOTHESIS SUPPORTS ITS DEVELOPMENT IN GENETICALLY PREDISPOSED INDIVIDUALS AFTER BEING EXPOSED TO CERTAIN ENVIRONMENTAL TRIGGERS. GENETIC PREDISPOSITION IS LINKED TO THE PRESENCE OF CERTAIN HLA ALLELES, MAINLY HLA-DR3 AND HLA-DR4. HOWEVER, A WIDE NUMBER OF NON-HLA EPITOPES HAVE ALSO BEEN ASSOCIATED WITH THE DISEASE ALTHOUGH DATA VARY SIGNIFICANTLY AMONG DIFFERENT ETHNIC GROUPS. THEREFORE, IT IS LIKELY THAT EPIGENETIC ALTERATIONS MAY ALSO PLAY A CRUCIAL ROLE IN DISEASE'S PATHOGENESIS, ALTHOUGH NOT YET EXTENSIVELY STUDIED. THE AIM OF THIS REVIEW WAS TO SUMMARIZE THE GENETIC AND ENVIRONMENTAL FACTORS THAT HAVE BEEN ASSOCIATED WITH AIH, BUT ALSO TO OPEN NEW INSIGHTS TOWARDS THE ROLE OF EPIGENETIC MODIFICATIONS IN THE ETIOLOGY OF THE DISEASE. 2021 7 407 30 ANALYSIS OF FOXP3+ REGULATORY T CELLS THAT DISPLAY APPARENT VIRAL ANTIGEN SPECIFICITY DURING CHRONIC HEPATITIS C VIRUS INFECTION. WE REPORTED PREVIOUSLY THAT A PROPORTION OF NATURAL CD25(+) CELLS ISOLATED FROM THE PBMC OF HCV PATIENTS CAN FURTHER UPREGULATE CD25 EXPRESSION IN RESPONSE TO HCV PEPTIDE STIMULATION IN VITRO, AND PROPOSED THAT VIRUS-SPECIFIC REGULATORY T CELLS (TREG) WERE PRIMED AND EXPANDED DURING THE DISEASE. HERE WE DESCRIBE EPIGENETIC ANALYSIS OF THE FOXP3 LOCUS IN HCV-RESPONSIVE NATURAL CD25(+) CELLS AND SHOW THAT THESE CELLS ARE NOT ACTIVATED CONVENTIONAL T CELLS EXPRESSING FOXP3, BUT HARD-WIRED TREG WITH A STABLE FOXP3 PHENOTYPE AND FUNCTION. OF APPROXIMATELY 46,000 GENES ANALYZED IN GENOME WIDE TRANSCRIPTION PROFILING, ABOUT 1% WERE DIFFERENTIALLY EXPRESSED BETWEEN HCV-RESPONSIVE TREG, HCV-NON-RESPONSIVE NATURAL CD25(+) CELLS AND CONVENTIONAL T CELLS. EXPRESSION PROFILES, INCLUDING CELL DEATH, ACTIVATION, PROLIFERATION AND TRANSCRIPTIONAL REGULATION, SUGGEST A SURVIVAL ADVANTAGE OF HCV-RESPONSIVE TREG OVER THE OTHER CELL POPULATIONS. SINCE NO TREG-SPECIFIC ACTIVATION MARKER IS KNOWN, WE TESTED 97 NS3-DERIVED PEPTIDES FOR THEIR ABILITY TO ELICIT CD25 RESPONSE (ASSUMING IT IS A SURROGATE MARKER), ACCOMPANIED BY HIGH RESOLUTION HLA TYPING OF THE PATIENTS. SOME REACTIVE PEPTIDES OVERLAPPED WITH PREVIOUSLY DESCRIBED EFFECTOR T CELL EPITOPES. OUR DATA OFFERS NEW INSIGHTS INTO HCV IMMUNE EVASION AND TOLERANCE, AND HIGHLIGHTS THE NON-SELF SPECIFIC NATURE OF TREG DURING INFECTION. 2009 8 4030 26 LUPUS ERYTHEMATOSUS: A SHORT ACCOUNT. LUPUS ERYTHEMATOSUS IS A CHRONIC AUTOIMMUNE INFLAMMATORY DISEASE WITH DIVERSE CLINICAL MANIFESTATIONS INCLUDING ARTHRITIS, SKIN DISORDERS AND KIDNEY DISEASE. PATHOLOGICALLY IT IS CHARACTERISED BY COMPLEX INTERACTIONS BETWEEN MULTIPLE GENETIC, EPIGENETIC AND EXTRANEOUS FACTORS; AND SEROLOGICALLY BY THE PRESENCE OF A VARIETY OF ANTIBODIES WHICH ARE REACTIVE TO INTRACELLULAR MOLECULAR CONSTITUENTS. IMPAIRED CLEARANCE OF APOPTOTIC CELLS AND OF IMMUNE COMPLEXES, LOSS OF IMMUNE TOLERANCE TO SELF-ANTIGENS AND DYSREGULATION OF THE CYTOKINE NETWORK ACT SYNERGISTICALLY WITH EXTRANEOUS FACTORS SUCH AS ULTRAVIOLET RADIATION, VIRUSES AND CERTAIN DRUGS TO INDUCE AND SUSTAIN LUPUS ERYTHEMATOSUS. 2011 9 1323 34 DENDRITIC CELLS IN SYSTEMIC LUPUS ERYTHEMATOSUS: FROM PATHOGENESIS TO THERAPEUTIC APPLICATIONS. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A SEVERE CHRONIC SYSTEMIC AUTOIMMUNE DISEASE CAUSED BY COMPLICATED INTERACTIONS AMONG GENETIC, EPIGENETIC, AND IMMUNOLOGICAL FACTORS. DENDRITIC CELLS (DCS), AS THE MOST IMPORTANT ANTIGEN-PRESENTING CELLS, PLAY PIVOTAL ROLES IN BOTH TRIGGERING PATHOGENIC AUTOIMMUNE RESPONSES, AND ALSO MAINTAINING IMMUNE TOLERANCE. DISTINCT DC SUBSETS ARE ENDOWED WITH DIVERSIFIED PHENOTYPIC AND FUNCTIONAL CHARACTERISTICS, AND PLAY VARIABLE ROLES IN SHAPING IMMUNITY AND TOLERANCE DURING THE DEVELOPMENT OF SLE. ABNORMAL ACTIVATION OR DISABLED TOLERANCE OF DCS NOT ONLY TRIGGERS ABERRANT PRODUCTION OF INFLAMMATORY MEDIATORS AND TYPE I INTERFERONS LEADING TO PATHOGENIC INNATE IMMUNITY AND AUTOINFLAMMATION, BUT ALSO CAUSES AN IMBALANCE OF EFFECTOR VERSUS REGULATORY T CELL RESPONSES AND SUSTAINED PRODUCTION OF AUTO-ANTIBODIES FROM B CELLS, LEADING TO CONTINUOUSLY AMPLIFIED AUTOIMMUNE PATHOGENESIS IN SLE. OVER THE PAST DECADE, SIGNIFICANT PROGRESS HAS BEEN MADE IN REVEALING THE CHANGES OF DC ACCUMULATION OR FUNCTION IN SLE, AND HOW THE FUNCTIONAL DYSREGULATIONS OF DCS CONTRIBUTE TO THE PATHOLOGICAL INFLAMMATION OF SLE, LEADING TO BREAKTHROUGHS IN DC-BASED THERAPEUTICS IN THE TREATMENT OF SLE. IN THIS REVIEW, WE REVIEW THE RECENT ADVANCES IN THE ACTIVATION AND FUNCTION OF THE MAJOR DC SUBSETS IN THE PATHOGENESIS OF SLE AS WELL AS THE THERAPEUTIC POTENTIAL OF TARGETING DC SUBSET OR STATUS AGAINST SLE. 2022 10 5912 34 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 11 2257 24 EPIGENETIC PERSPECTIVES IN SYSTEMIC LUPUS ERYTHEMATOSUS: PATHOGENESIS, BIOMARKERS, AND THERAPEUTIC POTENTIALS. SYSTEM LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC AUTOIMMUNE DISEASE CHARACTERIZED BY THE PRODUCTION OF AUTOANTIBODIES THAT CAUSE WIDESPREAD TISSUE DAMAGE. THE UNDERLYING ETIOLOGY REMAINS LARGELY UNKNOWN. ABERRANT EPIGENETICS PLAYS ESSENTIAL ROLES IN THE PATHOGENESIS OF SLE. THIS REVIEW EXPLORES THE LINKS BETWEEN DNA METHYLATION, HISTONE MODIFICATIONS, AND MIRNAS IN SLE AND HIGHLIGHTS HOW THESE FACTORS MAY INTERACT IN SLE PATHOGENESIS. WE ALSO DISCUSS HOW FURTHERING OUR KNOWLEDGE OF EPIGENETICS IN LUPUS PROVIDES HOPE FOR FINDING NEW DIAGNOSTIC AND PROGNOSTIC BIOMARKERS AND NOVEL THERAPEUTIC TARGETS AND STRATEGIES. 2010 12 2990 28 GENETIC FACTORS PREDISPOSING TO SYSTEMIC LUPUS ERYTHEMATOSUS AND LUPUS NEPHRITIS. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC INFLAMMATORY DISEASE CHARACTERIZED BY A LOSS OF TOLERANCE TO SELF-ANTIGENS AND THE PRODUCTION OF HIGH TITERS OF SERUM AUTOANTIBODIES. LUPUS NEPHRITIS CAN AFFECT UP TO 74% OF SLE PATIENTS, PARTICULARLY THOSE OF HISPANIC AND AFRICAN ANCESTRIES, AND REMAINS A MAJOR CAUSE OF MORBIDITY AND MORTALITY. A GENETIC ETIOLOGY IN SLE IS NOW WELL SUBSTANTIATED. THANKS TO EXTENSIVE COLLABORATIONS, EXTRAORDINARY PROGRESS HAS BEEN MADE IN THE PAST FEW YEARS AND THE NUMBER OF CONFIRMED GENES PREDISPOSING TO SLE HAS CATAPULTED TO APPROXIMATELY 30. STUDIES OF OTHER FORMS OF GENETIC VARIATION, SUCH AS COPY NUMBER VARIANTS AND EPIGENETIC ALTERATIONS, ARE EMERGING AND PROMISE TO REVOLUTIONIZE OUR KNOWLEDGE ABOUT DISEASE MECHANISMS. HOWEVER, TO DATE LITTLE PROGRESS HAS BEEN MADE ON THE IDENTIFICATION OF GENETIC FACTORS SPECIFIC TO LUPUS NEPHRITIS. ON THE NEAR HORIZON, TWO LARGE-SCALE EFFORTS, A COLLABORATIVE META-ANALYSIS OF LUPUS NEPHRITIS BASED ON ALL GENOME-WIDE ASSOCIATION DATA IN CAUCASIANS AND PARALLEL SCANS IN FOUR OTHER ETHNICITIES, ARE POISED TO MAKE FUNDAMENTAL DISCOVERIES IN THE GENETICS OF LUPUS NEPHRITIS. COLLECTIVELY, THESE FINDINGS WILL SHOW THAT A BROAD ARRAY OF PATHWAYS UNDERLINES THE GENETIC HETEROGENEITY OF SLE AND LUPUS NEPHRITIS, AND PROVIDE POTENTIAL AVENUES FOR THE DEVELOPMENT OF NOVEL THERAPIES. 2010 13 2731 21 EXPLORING THE COMPLEX RELATIONSHIP BETWEEN MICROBIOTA AND SYSTEMIC LUPUS ERYTHEMATOSUS. PURPOSE OF REVIEW: SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC AUTOIMMUNE DISEASE CHARACTERIZED BY VARIOUS AUTOANTIBODIES AND MULTI-ORGAN. MICROBIOTA DYSBIOSIS IN THE GUT, SKIN, ORAL, AND OTHER SURFACES HAS A SIGNIFICANT IMPACT ON SLE DEVELOPMENT. THIS ARTICLE SUMMARIZES RELEVANT RESEARCH AND PROVIDES NEW MICROBIOME-RELATED STRATEGIES FOR EXPLORING THE MECHANISMS AND TREATING PATIENTS WITH SLE. RECENT FINDINGS: SLE PATIENTS HAVE DISRUPTIONS IN MULTIPLE MICROBIOMES, WITH THE GUT MICROBIOTA (BACTERIA, VIRUSES, AND FUNGI) AND THEIR METABOLITES BEING THE MOST THOROUGHLY RESEARCHED. THIS DYSBIOSIS CAN PROMOTE SLE PROGRESSION THROUGH MECHANISMS SUCH AS THE LEAKY GUT, MOLECULAR MIMICRY, AND EPIGENETIC REGULATION. NOTWITHSTANDING STUDY CONSTRAINTS ON THE RELATIONSHIP BETWEEN MICROBIOTA AND SLE, SPECIFIC INTERVENTIONS TARGETING THE GUT MICROBIOTA, SUCH AS PROBIOTICS, DIETARY MANAGEMENT, AND FECAL MICROBIOTA TRANSPLANTATION, HAVE EMERGED AS PROMISING SLE THERAPEUTICS. 2023 14 3545 27 IMMUNOMETABOLISM IN THE PATHOGENESIS OF SYSTEMIC LUPUS ERYTHEMATOSUS. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A TYPICAL AUTOIMMUNE DISEASE CHARACTERIZED BY CHRONIC INFLAMMATION AND PATHOGENIC AUTO-ANTIBODIES. APART FROM B CELLS, DYSREGULATION OF OTHER IMMUNE CELLS ALSO PLAYS AN ESSENTIAL ROLE IN THE PATHOGENESIS AND DEVELOPMENT OF THE DISEASE INCLUDING CD4(+)T CELLS, DENDRITIC CELLS, MACROPHAGES AND NEUTROPHILS. SINCE METABOLIC PROGRAMS CONTROL IMMUNE CELL FATE AND FUNCTION, THEY ARE CRITICAL CHECKPOINTS IN AN EFFECTIVE IMMUNE RESPONSE AND ARE INVOLVED IN THE ETIOLOGY OF AUTOIMMUNE DISEASE. IN ADDITION, MITOCHONDRIA AND OXIDATIVE STRESS ARE BOTH INVOLVED IN CELLULAR METABOLISM AND IS ALSO ESSENTIAL IN IMMUNE RESPONSE. IN THIS REVIEW, APART FROM THE DISTURBED IMMUNE SYSTEM, WE WILL DISCUSS MITOCHONDRIAL DYSFUNCTION, OXIDATIVE STRESS, ABNORMAL METABOLISM (INCLUDING GLUCOSE, LIPID AND AMINO ACID METABOLISM) OF IMMUNE CELLS AS WELL AS EPIGENETIC CONTROL OF METABOLISM REPROGRAMMING TO ELUCIDATE THE UNDERLYING PATHOGENIC MECHANISMS OF SYSTEMIC LUPUS ERYTHEMATOSUS. 2020 15 3209 20 HEALTH DISPARITIES IN SYSTEMIC LUPUS ERYTHEMATOSUS. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC MULTISYSTEM AUTOIMMUNE DISEASE CHARACTERIZED BY AUTOANTIBODY PRODUCTION AND DIVERSE CLINICAL MANIFESTATIONS. THE MANY COMPLEX, OVERLAPPING, AND CLOSELY ASSOCIATED FACTORS THAT INFLUENCE SLE SUSCEPTIBILITY AND OUTCOMES INCLUDE ETHNIC DISPARITIES, LOW ADHERENCE TO MEDICATIONS, AND POVERTY, AND GEOGRAPHY. EPIGENETIC MECHANISMS MAY PROVIDE THE LINK BETWEEN THESE ENVIRONMENTAL EXPOSURES AND BEHAVIORS AND THE DISPROPORTIONATE BURDEN OF SLE SEEN IN ETHNIC MINORITIES. ATTENTION TO THESE MODIFIABLE SOCIAL DETERMINANTS OF HEALTH WOULD NOT ONLY IMPROVE OUTCOMES FOR VULNERABLE PATIENTS WITH SLE BUT LIKELY REDUCE SUSCEPTIBILITY TO SLE AS WELL THROUGH EPIGENETIC CHANGES. 2020 16 6376 32 THE ROLE OF NEUTROPHILS IN TRAINED IMMUNITY. THE PRINCIPLE OF TRAINED IMMUNITY REPRESENTS INNATE IMMUNE MEMORY DUE TO SUSTAINED, MAINLY EPIGENETIC, CHANGES TRIGGERED BY ENDOGENOUS OR EXOGENOUS STIMULI IN BONE MARROW (BM) PROGENITORS (CENTRAL TRAINED IMMUNITY) AND THEIR INNATE IMMUNE CELL PROGENY, THEREBY TRIGGERING ELEVATED RESPONSIVENESS AGAINST SECONDARY STIMULI. BM PROGENITORS CAN RESPOND TO MICROBIAL AND STERILE SIGNALS, THEREBY POSSIBLY ACQUIRING TRAINED IMMUNITY-MEDIATED LONG-LASTING ALTERATIONS THAT MAY SHAPE THE FATE AND FUNCTION OF THEIR PROGENY, FOR EXAMPLE, NEUTROPHILS. NEUTROPHILS, THE MOST ABUNDANT INNATE IMMUNE CELL POPULATION, ARE PRODUCED IN THE BM FROM COMMITTED PROGENITOR CELLS IN A PROCESS DESIGNATED GRANULOPOIESIS. NEUTROPHILS ARE THE FIRST RESPONDERS AGAINST INFECTIOUS OR INFLAMMATORY CHALLENGES AND HAVE VERSATILE FUNCTIONS IN IMMUNITY. TOGETHER WITH OTHER INNATE IMMUNE CELLS, NEUTROPHILS ARE EFFECTORS OF PERIPHERAL TRAINED IMMUNITY. HOWEVER, GIVEN THE SHORT LIFETIME OF NEUTROPHILS, THEIR ABILITY TO ACQUIRE IMMUNOLOGICAL MEMORY MAY LIE IN THE CENTRAL TRAINING OF THEIR BM PROGENITORS RESULTING IN GENERATION OF REPROGRAMMED, THAT IS, "TRAINED", NEUTROPHILS. ALTHOUGH TRAINED IMMUNITY MAY HAVE BENEFICIAL EFFECTS IN INFECTION OR CANCER, IT MAY ALSO MEDIATE DETRIMENTAL OUTCOMES IN CHRONIC INFLAMMATION. HERE, WE REVIEW THE EMERGING RESEARCH AREA OF TRAINED IMMUNITY WITH A PARTICULAR EMPHASIS ON THE ROLE OF NEUTROPHILS AND GRANULOPOIESIS. 2023 17 2697 22 EX VIVO MODELS OF CHRONIC GRANULOMATOUS DISEASE. INDUCED PLURIPOTENT STEM CELLS (IPSCS) ARE PLURIPOTENT STEM CELLS THAT CAN BE ESTABLISHED FROM DEDIFFERENTIATION OF ALL SOMATIC CELL TYPES BY EPIGENETIC PHENOMENA. IPSCS CAN BE DIFFERENTIATED INTO ANY MATURE CELLS LIKE NEURONS, HEPATOCYTES, OR PANCREATIC CELLS THAT HAVE NOT BEEN EASILY AVAILABLE TO DATE. THUS, IPSCS ARE WIDELY USED FOR DISEASE MODELING, DRUG DISCOVERY, AND CELL THERAPY DEVELOPMENT. HERE, WE DESCRIBE A PROTOCOL TO OBTAIN HUMAN MATURE AND FUNCTIONAL NEUTROPHILS AND MACROPHAGES AS EX VIVO MODELS OF X-LINKED CHRONIC GRANULOMATOUS DISEASE (X-CGD). THIS METHOD CAN BE APPLIED TO MODEL THE OTHER GENETIC FORMS OF CGD. WE ALSO DESCRIBE METHODS FOR TESTING THE CHARACTERISTICS AND FUNCTIONS OF NEUTROPHILS AND MACROPHAGES BY MORPHOLOGY, PHAGOCYTOSIS ASSAY, RELEASE OF GRANULE MARKERS OR CYTOKINES, CELL SURFACE MARKERS, AND NADPH OXIDASE ACTIVITY. 2019 18 6009 35 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 19 5886 32 SYSTEMIC LUPUS ERYTHEMATOSUS. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC MULTISYSTEM AUTOIMMUNE DISEASE THAT IS HIGHLY HETEROGENEOUS IN ITS PRESENTATION. THIS CAN POSE SIGNIFICANT CHALLENGES FOR PHYSICIANS RESPONSIBLE FOR THE DIAGNOSIS AND TREATMENT OF SUCH PATIENTS. SLE ARISES FROM A COMBINATION OF GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS. PATHOLOGICALLY, THE DISEASE IS PRIMARILY DRIVEN BY LOSS OF IMMUNE TOLERANCE AND ABNORMAL B- AND T-CELL FUNCTION. MAJOR ORGAN INVOLVEMENT MAY LEAD TO SIGNIFICANT MORBIDITY AND MORTALITY. CLASSIFICATION CRITERIA FOR SLE HAVE BEEN DEVELOPED LARGELY FOR RESEARCH PURPOSES; HOWEVER, THESE ARE ALSO WIDELY USED IN CLINICAL PRACTICE. ANTINUCLEAR ANTIBODIES ARE THE HALLMARK SEROLOGICAL FEATURE, OCCURRING IN OVER 95% OF PATIENTS WITH SLE AT SOME POINT DURING THEIR DISEASE. THE MAINSTAY OF TREATMENT IS ANTIMALARIAL DRUGS SUCH AS HYDROXYCHLOROQUINE, COMBINED WITH CORTICOSTEROIDS AND CONVENTIONAL IMMUNOSUPPRESSIVE DRUGS. AN INCREASING UNDERSTANDING OF PATHOGENESIS HAS FACILITATED A MOVE TOWARDS THE DEVELOPMENT OF TARGETED BIOLOGIC THERAPIES, WITH THE INTRODUCTION OF RITUXIMAB AND BELIMUMAB INTO CLINICAL PRACTICE. 2017 20 4958 28 PATHOGENESIS OF HUMAN SYSTEMIC LUPUS ERYTHEMATOSUS: A CELLULAR PERSPECTIVE. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC AUTOIMMUNE DISEASE AFFECTING MULTIPLE ORGANS. A COMPLEX INTERACTION OF GENETICS, ENVIRONMENT, AND HORMONES LEADS TO IMMUNE DYSREGULATION AND BREAKDOWN OF TOLERANCE TO SELF-ANTIGENS, RESULTING IN AUTOANTIBODY PRODUCTION, INFLAMMATION, AND DESTRUCTION OF END-ORGANS. EMERGING EVIDENCE ON THE ROLE OF THESE FACTORS HAS INCREASED OUR KNOWLEDGE OF THIS COMPLEX DISEASE, GUIDING THERAPEUTIC STRATEGIES AND IDENTIFYING PUTATIVE BIOMARKERS. RECENT FINDINGS INCLUDE THE CHARACTERIZATION OF GENETIC/EPIGENETIC FACTORS LINKED TO SLE, AS WELL AS CELLULAR EFFECTORS. NOVEL OBSERVATIONS HAVE PROVIDED AN IMPROVED UNDERSTANDING OF THE CONTRIBUTION OF TISSUE-SPECIFIC FACTORS AND ASSOCIATED DAMAGE, T AND B LYMPHOCYTES, AS WELL AS INNATE IMMUNE CELL SUBSETS AND THEIR CORRESPONDING ABNORMALITIES. THE INTRICATE WEB OF INVOLVED FACTORS AND PATHWAYS DICTATES THE ADOPTION OF TAILORED THERAPEUTIC APPROACHES TO CONQUER THIS DISEASE. 2017