1 1694 104 DUST MITE ALLERGEN-SPECIFIC IMMUNOTHERAPY INCREASES IL4 DNA METHYLATION AND INDUCES DER P-SPECIFIC T CELL TOLERANCE IN CHILDREN WITH ALLERGIC ASTHMA. ALLERGEN-SPECIFIC IMMUNOTHERAPY (ALLERGEN-SIT) IS A HIGHLY EFFECTIVE TREATMENT FOR CHILDREN WITH ALLERGIC ASTHMA (AA), AN IMMUNE-MEDIATED CHRONIC DISEASE LEADING TO BRONCHIAL MUSCLE HYPERTROPHY AND AIRWAY OBSTRUCTION IN RESPONSE TO SPECIFIC ALLERGENS. T HELPER CELLS AND SECRETED CYTOKINES PLAY IMPORTANT ROLES IN THE PATHOGENESIS OF ASTHMA, AND EPIGENETIC MODULATION CONTROLS GENES IMPORTANT FOR T CELL DEVELOPMENT AND CYTOKINE EXPRESSION. THIS STUDY EVALUATED T HELPER CELL-SECRETED CYTOKINES AND DNA METHYLATION PATTERNS IN CHILDREN TREATED WITH DERMATOPHAGOIDES PTERONYSSINUS (DER P) ALLERGEN-SIT. OUR RESULTS SHOWED THAT AFTER DER P CHALLENGE, PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) FROM THE SIT GROUP, COMPARED WITH THE NON-SIT AA GROUP, PRODUCED LOWER LEVELS OF IL-4, IL-5 AND IL-2. THE SIT GROUP, COMPARED WITH THE AA GROUP, EXHIBITED DECREASED SENSITIVITY TO THE DER P ALLERGEN, CONCURRENT WITH IL-4 DOWN-MODULATION DUE TO INCREASED PROMOTER DNA METHYLATION, AS ESTIMATED IN PBMCS. OUR RESULTS SHOWED THAT SIT DECREASED IL-4 AND IL-5, AND INHIBITED T CELL PROLIFERATION, BY INHIBITING IL-2 PRODUCTION AFTER THE SPECIFIC ALLERGEN CHALLENGE. THESE RESULTS SUGGEST THAT DECREASED IL-2 PRODUCTION AND INCREASED IL-4 CYTOKINE PROMOTER METHYLATION IS A POTENTIAL MECHANISM OF DER P-SPECIFIC ALLERGEN DESENSITIZATION IMMUNOTHERAPY. 2018 2 5398 28 REDUCED MOUSE ALLERGEN IS ASSOCIATED WITH EPIGENETIC CHANGES IN REGULATORY GENES, BUT NOT MOUSE SENSITIZATION, IN ASTHMATIC CHILDREN. CHRONIC EXPOSURE TO MOUSE ALLERGEN MAY CONTRIBUTE GREATLY TO THE INNER-CITY ASTHMA BURDEN. WE HYPOTHESIZED THAT REDUCING MOUSE ALLERGEN EXPOSURE MAY MODULATE THE IMMUNOPATHOLOGY UNDERLYING SYMPTOMATIC PEDIATRIC ALLERGIC ASTHMA, AND THAT THIS OCCURS THROUGH EPIGENETIC REGULATION. TO TEST THIS HYPOTHESIS, WE STUDIED A COHORT OF MOUSE SENSITIZED, PERSISTENT ASTHMATIC INNER-CITY CHILDREN UNDERGOING MOUSE ALLERGEN-TARGETED INTEGRATED PEST MANAGEMENT (IPM) VS EDUCATION IN A RANDOMIZED CONTROLLED INTERVENTION TRIAL. WE FOUND THAT DECREASING MOUSE ALLERGEN EXPOSURE, BUT NOT COCKROACH, WAS ASSOCIATED WITH REDUCED FOXP3 BUCCAL DNA PROMOTER METHYLATION, BUT THIS WAS UNRELATED TO MOUSE SPECIFIC IGE PRODUCTION. THIS FINDING SUGGESTS THAT THE ENVIRONMENTAL EPIGENETIC REGULATION OF AN IMMUNOMODULATORY GENE MAY OCCUR FOLLOWING CHANGING ALLERGEN EXPOSURES IN SOME HIGHLY EXPOSED COHORTS. GIVEN THE CLINICAL AND PUBLIC HEALTH IMPORTANCE OF INNER-CITY PEDIATRIC ASTHMA AND THE POTENTIAL IMPACT OF ENVIRONMENTAL INTERVENTIONS, FURTHER STUDIES WILL BE NEEDED TO CORROBORATE CHANGES IN EPIGENETIC REGULATION FOLLOWING CHANGING EXPOSURES OVER TIME, AND DETERMINE THEIR IMPACT ON ASTHMA MORBIDITY IN SUSCEPTIBLE CHILDREN. 2017 3 6104 31 THE EMERGING ROLE OF HISTONE DEACETYLASE 1 IN ALLERGIC DISEASES. HISTONE DEACETYLASE 1 (HDAC1) IS A UNIQUE MEMBER OF THE CLASSES I HDACS AND HELPS TO REGULATE ACUTE AND CHRONIC ADAPTATION TO ENVIRONMENTAL STIMULI SUCH AS ALLERGEN, STRESS. ALLERGIC DISEASES ARE COMPLEX DISEASES RESULTING FROM THE EFFECT OF MULTIPLE GENETIC AND INTERACTING FOREIGN SUBSTANCES. EPIGENETICS PLAY AN IMPORTANT ROLE IN BOTH PATHOLOGICAL AND IMMUNOMODULATORY CONDITIONS OF ALLERGIC DISEASES. TO BE CONSISTENT WITH THIS ROLE, RECENT EVIDENCE STRONGLY SUGGESTS THAT HISTONE DEACETYLASE 1 (HDAC1) PLAYS A CRITICAL ROLE IN ALLERGIC RESPONSE. HDAC1 EXPRESSION IS STIMULATED BY ALLERGEN AND ATTRIBUTES TO INCREASE T HELPER 2 (TH2) CYTOKINE LEVELS, DECREASE TH1/TH17 CELLS AND ANTI-INFLAMMATORY CYTOKINE INTERLEUKIN-10 (IL-10), AND TWIK-RELATED POTASSIUM CHANNEL-1 (TREK-1) EXPRESSION. THIS REVIEW FOCUSES ON THE CONTRIBUTION OF HDAC1 AND THE REGULATORY ROLE IN CHARACTERIZING ALLERGIC ENDOTYPES WITH COMMON MOLECULAR PATHWAYS AND UNDERSTANDING ALLERGIC MULTIMORBIDITY RELATIONSHIPS, AS WELL AS ADDRESSING THEIR POTENTIAL AS THERAPEUTIC TARGETS FOR THESE CONDITIONS. 2022 4 3518 27 IGE SENSITIZATION PROFILES DIFFER BETWEEN ADULT PATIENTS WITH SEVERE AND MODERATE ATOPIC DERMATITIS. BACKGROUND: ATOPIC DERMATITIS (AD) IS A COMPLEX CHRONIC INFLAMMATORY DISEASE WHERE ALLERGENS CAN ACT AS SPECIFIC TRIGGERING FACTORS. AIM: TO CHARACTERIZE THE SPECIFICITIES OF IGE-REACTIVITY IN PATIENTS WITH AD TO A BROAD PANEL OF EXOGENOUS ALLERGENS INCLUDING MICROBIAL AND HUMAN ANTIGENS. METHODOLOGY: ADULT PATIENTS WITH AD WERE GROUPED ACCORDING TO THE SCORAD INDEX, INTO SEVERE (N = 53) AND MODERATE AD (N = 126). AS CONTROLS 43 PATIENTS WERE INCLUDED WITH SEBORRHOEIC ECZEMA AND 97 INDIVIDUALS WITHOUT HISTORY OF ALLERGY OR SKIN DISEASES. SPECIFIC IGE REACTIVITY WAS ASSESSED IN PLASMA USING PHADIATOP(R), IMMUNOCAP, MICRO-ARRAYED ALLERGENS, DOT-BLOTTED RECOMBINANT MALASSEZIA SYMPODIALIS ALLERGENS, AND IMMUNE-BLOTTED MICROBIAL AND HUMAN PROTEINS. RESULTS: IGE REACTIVITY WAS DETECTED IN 92% OF PATIENTS WITH SEVERE AND 83% OF PATIENTS WITH MODERATE AD. SENSITIZATION TO CAT ALLERGENS OCCURRED MOST FREQUENTLY, FOLLOWED BY SENSITIZATION TO BIRCH POLLEN, GRASS POLLEN, AND TO THE SKIN COMMENSAL YEAST M. SYMPODIALIS. PATIENTS WITH SEVERE AD SHOWED A SIGNIFICANTLY HIGHER FREQUENCY OF IGE REACTIVITY TO ALLERGENS LIKE CAT (RFEL D 1) AND HOUSE DUST MITE (RDER P 4 AND 10), TO STAPHYLOCOCCUS AUREUS, M. SYMPODIALIS, AND TO HUMAN ANTIGENS. IN CONTRAST, THERE WERE NO SIGNIFICANT DIFFERENCES IN THE FREQUENCIES OF IGE REACTIVITY TO THE GRASS POLLEN ALLERGENS RPHL P 1, 2, 5B, AND 6 BETWEEN THE TWO AD GROUPS. FURTHERMORE THE IGE REACTIVITY PROFILE OF PATIENTS WITH SEVERE AD WAS MORE SPREAD TOWARDS SEVERAL DIFFERENT ALLERGEN MOLECULES AS COMPARED TO PATIENTS WITH MODERATE AD. CONCLUSION: WE HAVE REVEALED A HITHERTO UNKNOWN DIFFERENCE REGARDING THE MOLECULAR SENSITIZATION PROFILE IN PATIENTS WITH SEVERE AND MODERATE AD. MOLECULAR PROFILING TOWARDS ALLERGEN COMPONENTS MAY PROVIDE A BASIS FOR FUTURE INVESTIGATIONS AIMING TO EXPLORE THE ENVIRONMENTAL, GENETIC AND EPIGENETIC FACTORS WHICH COULD BE RESPONSIBLE FOR THE DIFFERENT APPEARANCE AND SEVERITY OF DISEASE PHENOTYPES IN AD. 2016 5 2861 35 FROM TRAINED IMMUNITY IN ALLERGY TO TRAINED IMMUNITY-BASED ALLERGEN VACCINES. INNATE IMMUNE CELLS EXPERIENCE LONG LASTING METABOLIC AND EPIGENETIC CHANGES AFTER AN ENCOUNTER WITH SPECIFIC STIMULI. THIS FACILITATES ENHANCED IMMUNE RESPONSES UPON SECONDARY EXPOSITION TO BOTH THE SAME AND UNRELATED PATHOGENS, A PROCESS TERMED TRAINED IMMUNITY. TRAINED IMMUNITY-BASED VACCINES (TIBV) ARE VACCINES ABLE TO INDUCE INNATE IMMUNE MEMORY, THUS CONFERRING HETEROLOGOUS PROTECTION AGAINST A BROAD RANGE OF PATHOGENS. WHILE TRAINED IMMUNITY HAS BEEN WELL DOCUMENTED IN THE CONTEXT OF INFECTIONS AND MULTIPLE IMMUNE-MEDIATED DISEASES, THE ROLE OF INNATE IMMUNE MEMORY AND ITS CONTRIBUTION TO THE INITIATION AND MAINTENANCE OF CHRONIC ALLERGIC DISEASES REMAINS POORLY UNDERSTOOD. OVER THE LAST YEARS, DIFFERENT STUDIES ATTEMPTING TO UNCOVER THE ROLE OF TRAINED IMMUNITY IN ALLERGY HAVE EMERGED. EXPOSITION TO ENVIRONMENTAL FACTORS IMPACTING ALLERGY DEVELOPMENT SUCH AS ALLERGENS OR VIRUSES INDUCES THE REPROGRAMMING OF INNATE IMMUNE CELLS TO ACQUIRE A MORE PRO-INFLAMMATORY PHENOTYPE IN THE CONTEXT OF ASTHMA OR FOOD ALLERGY. SEVERAL STUDIES HAVE CONVINCINGLY DEMONSTRATED THAT PREVENTION OF VIRAL INFECTIONS USING TIBV CONTRIBUTES TO REDUCE WHEEZING ATTACKS IN CHILDREN, WHICH REPRESENT A HIGH-RISK FACTOR FOR ASTHMA DEVELOPMENT LATER IN LIFE. INNATE IMMUNE CELLS TRAINED WITH SPECIFIC STIMULI MIGHT ALSO ACQUIRE ANTI-INFLAMMATORY FEATURES AND PROMOTE TOLERANCE, WHICH MAY HAVE IMPORTANT IMPLICATIONS FOR CHRONIC INFLAMMATORY DISEASES SUCH AS ALLERGIES. RECENT FINDINGS SHOWED THAT ALLERGOID-MANNAN CONJUGATES, WHICH ARE NEXT GENERATION VACCINES FOR ALLERGEN-SPECIFIC IMMUNOTHERAPY (AIT), ARE ABLE TO REPROGRAM MONOCYTES INTO TOLEROGENIC DENDRITIC CELLS BY MECHANISMS DEPENDING ON METABOLIC AND EPIGENETIC REWIRING. A BETTER UNDERSTANDING OF THE UNDERLYING MECHANISMS OF TRAINED IMMUNITY IN ALLERGY WILL PAVE THE WAY FOR THE DESIGN OF NOVEL TRAINED IMMUNITY-BASED ALLERGEN VACCINES AS POTENTIAL ALTERNATIVE STRATEGIES FOR THE PREVENTION AND TREATMENT OF ALLERGIC DISEASES. 2023 6 6500 22 TRAINED IMMUNITY IN TYPE 2 IMMUNE RESPONSES. IMMUNOLOGICAL MEMORY OF INNATE IMMUNE CELLS, ALSO TERMED "TRAINED IMMUNITY", ALLOWS FOR CROSS-PROTECTION AGAINST DISTINCT PATHOGENS, BUT MAY ALSO DRIVE CHRONIC INFLAMMATION. RECENT STUDIES HAVE SHOWN THAT MEMORY RESPONSES ASSOCIATED WITH TYPE 2 IMMUNITY DO NOT SOLELY RELY ON ADAPTIVE IMMUNE CELLS, SUCH AS T- AND B CELLS, BUT ALSO INVOLVE THE INNATE IMMUNE SYSTEM AND EPITHELIAL CELLS. MEMORY RESPONSES HAVE BEEN DESCRIBED FOR MONOCYTES, MACROPHAGES AND AIRWAY EPITHELIAL CELLS OF ASTHMATIC PATIENTS AS WELL AS FOR MACROPHAGES AND GROUP 2 INNATE LYMPHOID CELLS (ILC2) FROM ALLERGEN-SENSITIZED OR HELMINTH-INFECTED MICE. THE METABOLIC AND EPIGENETIC MECHANISMS THAT MEDIATE ALLERGEN- OR HELMINTH-INDUCED REPROGRAMMING OF INNATE IMMUNE CELLS ARE ONLY BEGINNING TO BE UNCOVERED. TRAINED IMMUNITY HAS BEEN IMPLICATED IN HELMINTH-DRIVEN IMMUNE REGULATION AND ALLERGEN-SPECIFIC IMMUNOTHERAPY, SUGGESTING ITS EXPLOITATION IN FUTURE THERAPIES. HERE, WE DISCUSS RECENT ADVANCES AND KEY REMAINING QUESTIONS REGARDING THE MECHANISMS AND FUNCTIONS OF TRAINED TYPE 2 IMMUNITY IN INFECTION AND INFLAMMATION. 2022 7 6808 13 [EPIGENETICS IN ALLERGIC DISEASES AND ASTHMA]. ALLERGIC DISEASES AND ASTHMA ARE THE RESULT OF COMPLEX INTERACTIONS BETWEEN GENETIC PREDISPOSITION AND ENVIRONMENTAL FACTORS. ASTHMA IS ONE OF THE MOST PREVALENT CHRONIC DISEASE AMONG CHILDREN. IN THIS ARTICLE WE REVIEW SOME ENVIRONMENTAL FACTORS LIKE: ALLERGEN EXPOSITION, TOBACCO, BACTERIA, MICROBIAL COMPONENTS, DIET, OBESITY AND STRESS, WHICH INFLUENCES DURING INTRAUTERINE AND INFANCY LIFE IN THE EPIGENETIC REGULATION OF ASTHMA AND ALLERGIC DISEASES. THE REVIEW HAS BEEN DONE IN THREE MODELS: IN-VITRO, ANIMAL AND HUMAN. 2016 8 530 25 ASTHMA. ASTHMA IS THE MOST COMMON INFLAMMATORY DISEASE OF THE LUNGS. THE PREVALENCE OF ASTHMA IS INCREASING IN MANY PARTS OF THE WORLD THAT HAVE ADOPTED ASPECTS OF THE WESTERN LIFESTYLE, AND THE DISEASE POSES A SUBSTANTIAL GLOBAL HEALTH AND ECONOMIC BURDEN. ASTHMA INVOLVES BOTH THE LARGE-CONDUCTING AND THE SMALL-CONDUCTING AIRWAYS, AND IS CHARACTERIZED BY A COMBINATION OF INFLAMMATION AND STRUCTURAL REMODELLING THAT MIGHT BEGIN IN UTERO. DISEASE PROGRESSION OCCURS IN THE CONTEXT OF A DEVELOPMENTAL BACKGROUND IN WHICH THE POSTNATAL ACQUISITION OF ASTHMA IS STRONGLY LINKED WITH ALLERGIC SENSITIZATION. MOST ASTHMA CASES FOLLOW A VARIABLE COURSE, INVOLVING VIRAL-INDUCED WHEEZING AND ALLERGEN SENSITIZATION, THAT IS ASSOCIATED WITH VARIOUS UNDERLYING MECHANISMS (OR ENDOTYPES) THAT CAN DIFFER BETWEEN INDIVIDUALS. EACH SET OF ENDOTYPES, IN TURN, PRODUCES SPECIFIC ASTHMA CHARACTERISTICS THAT EVOLVE ACROSS THE LIFECOURSE OF THE PATIENT. STRONG GENETIC AND ENVIRONMENTAL DRIVERS OF ASTHMA INTERCONNECT THROUGH NOVEL EPIGENETIC MECHANISMS THAT OPERATE PRENATALLY AND THROUGHOUT CHILDHOOD. ASTHMA CAN SPONTANEOUSLY REMIT OR BEGIN DE NOVO IN ADULTHOOD, AND THE FACTORS THAT LEAD TO THE EMERGENCE AND REGRESSION OF ASTHMA, IRRESPECTIVE OF AGE, ARE POORLY UNDERSTOOD. NONETHELESS, THERE IS MOUNTING EVIDENCE THAT SUPPORTS A PRIMARY ROLE FOR STRUCTURAL CHANGES IN THE AIRWAYS WITH ASTHMA ACQUISITION, ON WHICH ALTERED INNATE IMMUNE MECHANISMS AND MICROBIOTA INTERACTIONS ARE SUPERIMPOSED. ON THE BASIS OF THE IDENTIFICATION OF NEW CAUSATIVE PATHWAYS, THE SUBPHENOTYPING OF ASTHMA ACROSS THE LIFECOURSE OF PATIENTS IS PAVING THE WAY FOR MORE-PERSONALIZED AND PRECISE PATHWAY-SPECIFIC APPROACHES FOR THE PREVENTION AND TREATMENT OF ASTHMA, CREATING THE REAL POSSIBILITY OF TOTAL PREVENTION AND CURE FOR THIS CHRONIC INFLAMMATORY DISEASE. 2015 9 3406 31 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 10 1566 35 DNA METHYLATION OF TH1/TH2 CYTOKINE GENES AFFECTS SENSITIZATION AND PROGRESS OF EXPERIMENTAL ASTHMA. BACKGROUND: EPIGENETIC CHANGES IN DNA METHYLATION HAVE RECENTLY BEEN DEMONSTRATED TO BE INVOLVED IN EFFECTOR T-CELL POLARIZATION, RESULTING IN DIFFERENTIAL SECRETION OF T(H)1 AND T(H)2 CYTOKINES. HOWEVER, THE CONTRIBUTION TO THE DEVELOPMENT OF A CHRONIC INFLAMMATORY PHENOTYPE REMAINS STILL UNCLEAR. OBJECTIVE: WE SOUGHT TO INVESTIGATE CHANGES IN DNA METHYLATION IN MARKER GENES OF T-CELL SUBSETS DURING ALLERGEN SENSITIZATION/CHALLENGE AND THEIR INFLUENCE ON THE DEVELOPMENT OF AN ALLERGIC AIRWAY INFLAMMATORY RESPONSE. METHODS: THE RELATIONSHIP BETWEEN CHANGES IN DNA METHYLATION AND PHENOTYPE DEVELOPMENT WERE EXAMINED IN A WELL-ESTABLISHED MODEL OF EXPERIMENTAL ASTHMA. DNA METHYLATION WAS INVESTIGATED AT GENOMIC LOCI ASSOCIATED WITH T(H)1 (IFNG PROMOTER) OR T(H)2 (CONSERVED NONCODING SEQUENCE 1 [CNS1]) CYTOKINE PRODUCTION BY USING BISULFITE PYROSEQUENCING. RESULTS: ANALYSIS OF CD4(+) T CELLS REVEALED A SIGNIFICANT INCREASE IN DNA METHYLATION AT THE IFNG PROMOTER AFTER ALLERGEN SENSITIZATION/CHALLENGE, WHICH CORRELATED WITH DECREASED IFN-GAMMA CYTOKINE EXPRESSION, WHEREAS ONLY MINOR CHANGES WERE OBSERVED AT THE CNS1 LOCUS. FURTHERMORE, THE INCREASE IN DNA METHYLATION AT THE IFNG PROMOTER COULD BE REVERSED WITH A DNA METHYLTRANSFERASE (DNMT) INHIBITOR IN VITRO AND IN VIVO WITH BENEFICIAL EFFECTS ON SENSITIZATION STATUS AND ALLERGIC PHENOTYPE. THE SPECIFIC IMPORTANCE OF THE DNA METHYLATION STATUS IN CD4(+) T CELLS COULD BE CONFIRMED BY USING ADOPTIVE TRANSFER EXPERIMENTS. CONCLUSION: WE HERE REPORT THE NOVEL FINDING THAT EPIGENETIC REGULATION IN T CELLS CONTRIBUTES TO THE DEVELOPMENT OF EXPERIMENTAL ASTHMA AND CAN BE TARGETED PHARMACOLOGICALLY. 2012 11 71 29 A MITOCHONDRIAL STAT3-METHIONINE METABOLISM AXIS PROMOTES ILC2-DRIVEN ALLERGIC LUNG INFLAMMATION. BACKGROUND: GROUP 2 INNATE LYMPHOID CELLS (ILC2S), THE INNATE COUNTERPART OF T(H)2 CELLS, PLAY A CRITICAL ROLE IN TYPE 2 IMMUNE RESPONSES. HOWEVER, THE MOLECULAR REGULATORY MECHANISMS OF ILC2S ARE STILL UNCLEAR. OBJECTIVE: THE AIM OF THIS STUDY WAS TO EXPLORE THE IMPORTANCE OF SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 (STAT3) TO ILC2 FUNCTION IN ALLERGIC LUNG INFLAMMATION. METHODS: ACUTE AND CHRONIC ASTHMA MODELS WERE ESTABLISHED BY INTRANASAL ADMINISTRATION OF THE PROTEASE ALLERGEN PAPAIN IN VAV(ICRE)STAT3(FL/FL), IL5(TDTOMATO-CRE)STAT3(FL/FL), AND RORC(CRE)STAT3(FL/FL) MICE TO VERIFY THE NECESSITY OF FUNCTIONAL STAT3 FOR ILC2 ALLERGIC RESPONSE. THE INTRINSIC ROLE OF STAT3 IN REGULATING ILC2 FUNCTION WAS EXAMINED BY GENERATION OF BONE MARROW CHIMERA MICE. THE UNDERLYING MECHANISM WAS STUDIED THROUGH CONFOCAL IMAGING, METABOLOMICS ANALYSIS, AND CHROMATIN IMMUNOPRECIPITATION QUANTITATIVE PCR. RESULTS: STAT3 IS ESSENTIAL FOR ILC2 EFFECTOR FUNCTION AND PROMOTES ILC2-DRIVEN ALLERGIC INFLAMMATION IN THE LUNG. MECHANISTICALLY, THE ALARMIN CYTOKINE IL-33 INDUCES A NONCANONICAL STAT3 PHOSPHORYLATION AT SERINE 727 IN ILC2S, LEADING TO TRANSLOCATION OF STAT3 INTO THE MITOCHONDRIA. MITOCHONDRIAL STAT3 FURTHER FACILITATES ADENOSINE TRIPHOSPHATE SYNTHESIS TO FUEL THE METHIONINE CYCLE AND GENERATION OF S-ADENOSYLMETHIONINE, WHICH SUPPORTS THE EPIGENETIC REPROGRAMMING OF TYPE 2 CYTOKINES IN ILC2S. STAT3 DEFICIENCY, INHIBITION OF STAT3 MITOCHONDRIAL TRANSLOCATION, OR BLOCKADE OF METHIONINE METABOLISM MARKEDLY DAMPENED THE ILC2 ALLERGIC RESPONSE AND AMELIORATED ALLERGIC LUNG INFLAMMATION. CONCLUSION: THE MITOCHONDRIAL STAT3-METHIONINE METABOLISM PATHWAY IS A KEY REGULATOR THAT SHAPES ILC2 EFFECTOR FUNCTION THROUGH EPIGENETIC REGULATION, AND THE RELATED PROTEINS OR METABOLITES REPRESENT POTENTIAL THERAPEUTIC TARGETS FOR ALLERGIC LUNG INFLAMMATION. 2022 12 343 36 ALTERATIONS OF THE LUNG METHYLOME IN ALLERGIC AIRWAY HYPER-RESPONSIVENESS. ASTHMA IS A CHRONIC AIRWAY DISORDER CHARACTERIZED BY RECURRENT ATTACKS OF BREATHLESSNESS AND WHEEZING, AFFECTING 300 MILLION PEOPLE AROUND THE WORLD (AVAILABLE AT: WWW.WHO.INT). TO DATE, GENETIC FACTORS ASSOCIATED WITH ASTHMA SUSCEPTIBILITY HAVE BEEN UNABLE TO EXPLAIN THE FULL ETIOLOGY OF ASTHMA. RECENT STUDIES HAVE DEMONSTRATED THAT THE EPIGENETIC DISRUPTION OF GENE EXPRESSION PLAYS AN EQUALLY IMPORTANT ROLE IN THE DEVELOPMENT OF ASTHMA THROUGH INTERACTION WITH OUR ENVIRONMENT. WE SENSITIZED 6-WEEK-OLD C57BL/6J MICE WITH HOUSE-DUST-MITE (HDM) EXTRACTS INTRAPERITONEALLY FOLLOWED BY 5 WEEKS OF EXPOSURE TO HDM CHALLENGES (THREE TIMES A WEEK) INTRATRACHEALLY. HDM-EXPOSED MICE SHOWED AN INCREASE IN AIRWAY HYPER-RESPONSIVENESS (AHR) AND INFLAMMATION TOGETHER WITH STRUCTURAL REMODELING OF THE AIRWAYS. WE APPLIED METHYLATED DNA IMMUNOPRECIPITATION-NEXT GENERATION SEQUENCING (MEDIP-SEQ) FOR PROFILING OF DNA METHYLATION CHANGES IN THE LUNGS IN RESPONSE TO HDM. WE OBSERVED ABOUT 20 MILLION READS BY A SINGLE-RUN OF MASSIVE PARALLEL SEQUENCING. WE PERFORMED BIOINFORMATICS AND PATHWAY ANALYSIS ON THE RAW SEQUENCING DATA TO IDENTIFY DIFFERENTIALLY METHYLATED CANDIDATE GENES IN HDM-EXPOSED MICE. SPECIFICALLY, WE HAVE REVEALED THAT THE TRANSFORMING GROWTH FACTOR BETA SIGNALING PATHWAY IS EPIGENETICALLY MODULATED BY CHRONIC EXPOSURE TO HDM. HERE, WE DEMONSTRATED THAT A SPECIFIC ALLERGEN MAY PLAY A ROLE IN AHR THROUGH AN EPIGENETIC MECHANISM BY DISRUPTING THE EXPRESSION OF GENES IN LUNGS THAT MIGHT BE INVOLVED IN AIRWAY INFLAMMATION AND REMODELING. OUR FINDINGS PROVIDE NEW INSIGHTS INTO THE POTENTIAL MECHANISMS BY WHICH ENVIRONMENTAL ALLERGENS INDUCE ALLERGIC ASTHMA AND SUCH INSIGHTS MAY ASSIST IN THE DEVELOPMENT OF NOVEL PREVENTIVE AND THERAPEUTIC OPTIONS FOR THIS DEBILITATIVE DISEASE. 2014 13 2369 32 EPIGENETIC REGULATION OF T-HELPER CELL DIFFERENTIATION, MEMORY, AND PLASTICITY IN ALLERGIC ASTHMA. AN ESTIMATED 300 MILLION PEOPLE CURRENTLY SUFFER FROM ASTHMA, WHICH CAUSES APPROXIMATELY 250 000 DEATHS A YEAR. ALLERGEN-SPECIFIC T-HELPER (TH) CELLS PRODUCE CYTOKINES THAT INDUCE MANY OF THE HALLMARK FEATURES OF ASTHMA INCLUDING AIRWAYS HYPERREACTIVITY, EOSINOPHILIC AND NEUTROPHILIC INFLAMMATION, MUCUS HYPERSECRETION, AND AIRWAY REMODELING. CYTOKINE-PRODUCING TH SUBSETS INCLUDING TH1 (IFN-GAMMA), TH2 (IL-4, IL-5, IL-13), TH9 (IL-9), TH17 (IL-17), TH22 (IL-22), AND T REGULATORY (IL-10) CELLS HAVE ALL BEEN SUGGESTED TO PLAY A ROLE IN THE DEVELOPMENT OF ASTHMA. TH DIFFERENTIATION INVOLVES GENETIC REGULATION OF GENE EXPRESSION THROUGH THE CONCERTED ACTION OF CYTOKINES, TRANSCRIPTION FACTORS, AND EPIGENETIC REGULATORS. WE DESCRIBE HOW TH DIFFERENTIATION AND PLASTICITY IS REGULATED BY EPIGENETIC HISTONE AND DNA MODIFICATIONS, WITH A FOCUS ON THE REGULATION OF HISTONE METHYLATION BY MEMBERS OF THE POLYCOMB AND TRITHORAX COMPLEXES. IN ADDITION, WE OUTLINE ENVIRONMENTAL INFLUENCES THAT COULD INFLUENCE EPIGENETIC REGULATION OF TH CELLS AND DISCUSS THE POTENTIAL TO REGULATE TH PLASTICITY AND FUNCTION THROUGH DRUGS TARGETING THE EPIGENETIC MACHINERY. IT IS ALSO BECOMING APPARENT THAT EPIGENETIC REGULATION OF ALLERGEN-SPECIFIC MEMORY TH CELLS MAY BE IMPORTANT IN THE DEVELOPMENT AND PERSISTENCE OF CHRONIC ALLERGIES. FINALLY, WE DESCRIBE HOW EPIGENETIC MODIFIERS REGULATE CYTOKINE MEMORY IN TH CELLS AND DESCRIBE RECENTLY IDENTIFIED HYBRID, PLASTIC, AND PATHOGENIC MEMORY TH SUBSETS THE CONTEXT OF ALLERGIC ASTHMA. 2017 14 5875 26 SYMPTOMS OF ALLERGIC RHINITIS IN WOMEN DURING EARLY PREGNANCY ARE ASSOCIATED WITH HIGHER PREVALENCE OF ALLERGIC RHINITIS IN THEIR OFFSPRING. BACKGROUND: EPIGENETIC CONTROL OF GENE EXPRESSION PROFILES IS A UBIQUITOUS MECHANISM DURING CELL DIFFERENTIATION, ORGANOGENESIS AND CHRONIC INFLAMMATORY REACTIONS. RECENT STUDIES HAVE SHOWN THAT ALLERGEN EXPOSURE DURING VERY EARLY PREGNANCY INCREASES BRONCHIAL HYPERSENSITIVITY IN OFFSPRING IN A MURINE MODEL OF BRONCHIAL ASTHMA. HOWEVER, NO SUCH PHENOMENA WERE REPORTED IN HUMANS. IN THE PRESENT STUDY, THE ROLE OF EPIGENETIC CONTROL IN THE ONSET OF ALLERGIC DISEASES WAS INVESTIGATED. METHODS: A TOTAL OF 400 PAIRS OF MOTHERS WITH PHYSICIAN-DIAGNOSED ALLERGIC RHINITIS (AR) AND THEIR OFFSPRING (AGE 7-18 MONTHS) WHO PARTICIPATED IN A LARGE-SCALE MEDICAL CHECK-UP WERE ENROLLED IN THIS RETROSPECTIVE COHORT STUDY. FAMILY HISTORY OF ALLERGIC DISEASES AND THE PRESENCE OR ABSENCE OF AR SYMPTOMS DURING PREGNANCY WERE INQUIRED ABOUT USING A SELF-ANSWERED QUESTIONNAIRE. A LOGISTIC REGRESSION MODEL ADJUSTED FOR AGE, GENDER, BIRTH MONTH AND FATHER'S HISTORY OF ALLERGIC DISEASES WAS STATISTICALLY ANALYZED. RESULTS: OFFSPRING WHOSE MOTHERS HAD ANY AR SYMPTOMS DURING EARLY PREGNANCY SHOWED A SIGNIFICANTLY HIGHER ADJUSTED ODDS RATIO FOR THE ONSET OF AR IN OFFSPRING THAN THOSE WHOSE MOTHERS HAD NO SYMPTOMS DURING PREGNANCY (ADJUSTED ODDS RATIO: 6.26, P = 0.036). HOWEVER, THE SYMPTOMS OF AR DURING LATE PREGNANCY SHOWED NO EFFECTS ON THE ODDS RATIO. IN CONTRAST, THE PRESENCE OR ABSENCE OF AR SYMPTOMS DURING EARLY OR LATE PREGNANCY SHOWED NO ASSOCIATION WITH THE PREVALENCE OF FOOD ALLERGY, ATOPIC DERMATITIS OR ASTHMA IN OFFSPRING. CONCLUSIONS: OUR RESULTS SUGGEST THE PRESENCE OF POSSIBLE EPIGENETIC MECHANISMS REGULATING THE ONSET OF AR IN HUMANS PRESUMABLY THROUGH INCREASED ORGAN-SPECIFIC HYPERSENSITIVITY. 2007 15 5898 22 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 2138 21 EPIGENETIC INHERITANCE OF FETAL GENES IN ALLERGIC ASTHMA. ASTHMA HAS BEEN ASSOCIATED WITH AN EXAGGERATED T-HELPER TYPE 2 (TH2) OVER TH1 RESPONSES TO ALLERGIC AND NONALLERGIC STIMULI, WHICH LEADS TO CHRONIC AIRWAY INFLAMMATION AND AIRWAY REMODELING. IN THE PRESENT ARTICLE, WE PROPOSE THAT MANY OF THE GENES INVOLVED IN IGE SYNTHESIS AND AIRWAYS (RE)MODELING IN ASTHMA ARE PERSISTENT OR REMINISCENT FETAL GENES WHICH MAY NOT BE SILENCED DURING EARLY INFANCY (OR LATE PREGNANCY). GENES OF THE EMBRYOLOGIC DIFFERENTIATION OF ECTODERMIC AND ENDODERMIC TISSUES MAY EXPLAIN SOME OF THE PATTERNS OF AIRWAY REMODELING IN ASTHMA. IN UTERO PROGRAMMING LEADS TO GENE EXPRESSION, THE PERSISTENCE OF WHICH MAY BE ASSOCIATED WITH EPIGENETIC INHERITANCE PHENOMENA INDUCED BY NONSPECIFIC ENVIRONMENTAL FACTORS. CLEAR DELINEATION OF THESE ISSUES MAY YIELD NEW INFORMATION ON THE MECHANISMS OF ASTHMA AND NEW TARGETS FOR THERAPEUTIC INTERVENTION AND PRIMARY PREVENTION. 2004 17 5996 31 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 18 4872 31 OUTSIDE-IN HYPOTHESIS REVISITED: THE ROLE OF MICROBIAL, EPITHELIAL, AND IMMUNE INTERACTIONS. OBJECTIVE: OUR UNDERSTANDING OF THE ORIGIN OF ALLERGIC DISEASES HAS INCREASED IN RECENT YEARS, HIGHLIGHTING THE IMPORTANCE OF MICROBIAL DYSBIOSIS AND EPITHELIAL BARRIER DYSFUNCTION IN AFFECTED TISSUES. EXPLORING THE MICROBIAL-EPITHELIAL-IMMUNE CROSSTALK UNDERLYING THE MECHANISMS OF ALLERGIC DISEASES WILL ALLOW THE DEVELOPMENT OF NOVEL PREVENTION AND TREATMENT STRATEGIES FOR ALLERGIC DISEASES. DATA SOURCES: THIS REVIEW SUMMARIZES THE RECENT ADVANCES IN MICROBIAL, EPITHELIAL, AND IMMUNE INTERACTIONS IN ATOPIC DERMATITIS, ALLERGIC RHINITIS, CHRONIC RHINOSINUSITIS, AND ASTHMA. STUDY SELECTIONS: WE PERFORMED A LITERATURE SEARCH, IDENTIFYING RELEVANT RECENT PRIMARY ARTICLES AND REVIEW ARTICLES. RESULTS: DYNAMIC CROSSTALK BETWEEN THE ENVIRONMENTAL FACTORS AND MICROBIAL, EPITHELIAL, AND IMMUNE CELLS IN THE DEVELOPMENT OF ATOPIC DERMATITIS, ALLERGIC RHINITIS, CHRONIC RHINOSINUSITIS, AND ASTHMA UNDERLIES THE PATHOGENESIS OF THESE DISEASES. THERE IS SUBSTANTIAL EVIDENCE IN THE LITERATURE SUGGESTING THAT ENVIRONMENTAL FACTORS DIRECTLY AFFECT BARRIER FUNCTION OF THE EPITHELIUM. IN ADDITION, T-HELPER 2 (T(H)2) CELLS, TYPE 2 INNATE LYMPHOID CELLS, AND THEIR CYTOKINE INTERLEUKIN 13 (IL-13) DAMAGE SKIN AND LUNG BARRIERS. THE EFFECTS OF ENVIRONMENTAL FACTORS MAY AT LEAST IN PART BE MEDIATED BY EPIGENETIC MECHANISMS. HISTONE DEACETYLASE ACTIVATION BY TYPE 2 IMMUNE RESPONSE HAS A MAJOR EFFECT ON LEAKY BARRIERS AND BLOCKING OF HISTONE DEACETYLASE ACTIVITY CORRECTS THE DEFECTIVE BARRIER IN HUMAN AIR-LIQUID INTERFACE CULTURES AND MOUSE MODELS OF ALLERGIC ASTHMA WITH RHINITIS. WE ALSO PRESENT AND DISCUSS A NOVEL DEVICE TO DETECT AND MONITOR SKIN BARRIER DYSFUNCTION, WHICH PROVIDES AN OPPORTUNITY TO RAPIDLY AND ROBUSTLY ASSESS DISEASE SEVERITY. CONCLUSION: A COMPLEX INTERPLAY BETWEEN ENVIRONMENTAL FACTORS, EPITHELIUM, AND THE IMMUNE SYSTEM IS INVOLVED IN THE DEVELOPMENT OF SYSTEMIC ALLERGIC DISEASES. 2020 19 6303 37 THE PUZZLE OF IMMUNE PHENOTYPES OF CHILDHOOD ASTHMA. ASTHMA REPRESENTS THE MOST COMMON CHRONIC CHILDHOOD DISEASE WORLDWIDE. WHEREAS PRESCHOOL CHILDREN PRESENT WITH WHEEZING TRIGGERED BY DIFFERENT FACTORS (MULTITRIGGER AND VIRAL WHEEZE), CLINICAL ASTHMA MANIFESTATION IN SCHOOL CHILDREN HAS PREVIOUSLY BEEN CLASSIFIED AS ALLERGIC AND NON-ALLERGIC ASTHMA. FOR BOTH, THE UNDERLYING IMMUNOLOGICAL MECHANISMS ARE NOT YET UNDERSTOOD IN DEPTH IN CHILDREN. TREATMENT IS STILL PRESCRIBED REGARDLESS OF UNDERLYING MECHANISMS, AND CHILDREN ARE NOT ALWAYS TREATED SUCCESSFULLY. THIS REVIEW SUMMARIZES RECENT KEY FINDINGS ON THE COMPLEX MECHANISMS OF THE DEVELOPMENT AND MANIFESTATION OF CHILDHOOD ASTHMA. WHEREAS TRADITIONAL CLASSIFICATION OF CHILDHOOD ASTHMA IS PRIMARILY BASED ON CLINICAL SYMPTOMS LIKE WHEEZING AND ATOPY, NOVEL APPROACHES TO SPECIFY ASTHMA PHENOTYPES ARE UNDER WAY AND FACE CHALLENGES SUCH AS INCLUDING THE STABILITY OF PHENOTYPES OVER TIME AND TRANSITION INTO ADULTHOOD. EPIDEMIOLOGICAL STUDIES ENCLOSE MORE INFORMATION ON THE PATIENT'S DISEASE HISTORY AND ENVIRONMENTAL INFLUENCES. LATEST STUDIES DEFINE ENDOTYPES BASED ON MOLECULAR AND CELLULAR MECHANISMS, FOR EXAMPLE DEFINING RISK AND PROTECTIVE SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) AND NEW IMMUNE PHENOTYPES, SHOWING PROMISING RESULTS. ALSO, REGULATORY T CELLS AND RECENTLY DISCOVERED T HELPER CELL SUBTYPES SUCH AS TH9 AND TH17 CELLS WERE SHOWN TO BE IMPORTANT FOR THE DEVELOPMENT OF ASTHMA. INNATE LYMPHOID CELLS (ILC) COULD PLAY A CRITICAL ROLE IN ASTHMA PATIENTS AS THEY PRODUCE DIFFERENT CYTOKINES ASSOCIATED WITH ASTHMA. EPIGENETIC FINDINGS SHOWED DIFFERENT ACETYLATION AND METHYLATION PATTERNS FOR CHILDREN WITH ALLERGIC AND NON-ALLERGIC ASTHMA. ON A POSTTRANSCRIPTIONAL LEVEL, MIRNAS ARE REGULATING FACTORS IDENTIFIED TO DIFFER BETWEEN ASTHMA PATIENTS AND HEALTHY CONTROLS AND ALSO INDICATE DIFFERENCES WITHIN ASTHMA PHENOTYPES. METABOLOMICS IS ANOTHER EXCITING CHAPTER IMPORTANT FOR ENDOTYPING ASTHMATIC CHILDREN. DESPITE THE DEVELOPMENT OF NEW BIOMARKERS AND THE DISCOVERY OF NEW IMMUNOLOGICAL MOLECULES, THE COMPLEX PUZZLE OF CHILDHOOD ASTHMA IS STILL FAR FROM BEING COMPLETED. ADDRESSING THE CURRENT CHALLENGES OF DISTINCT CLINICAL ASTHMA AND WHEEZE PHENOTYPES, INCLUDING THEIR STABILITY AND UNDERLYING ENDOTYPES, INVOLVES ADDRESSING THE INTERPLAY OF INNATE AND ADAPTIVE IMMUNE REGULATORY MECHANISMS IN LARGE, INTERDISCIPLINARY COHORTS. 2016 20 1973 40 EPIGENETIC ALTERATIONS BY DNA METHYLATION IN HOUSE DUST MITE-INDUCED AIRWAY HYPERRESPONSIVENESS. ASTHMA IS ONE OF THE MOST PREVALENT CHRONIC LUNG DISEASES, AFFECTING 235 MILLION INDIVIDUALS AROUND THE WORLD, WITH ITS RELATED MORBIDITY AND MORTALITY INCREASING STEADILY OVER THE LAST 20 YEARS. EXPOSURE TO THE ENVIRONMENTAL ALLERGEN, HOUSE DUST MITE (HDM), RESULTS IN AIRWAY INFLAMMATION WITH A VARIABLE DEGREE OF AIRWAY OBSTRUCTION. ALTHOUGH THERE HAS BEEN MUCH EXPERIMENTAL WORK IN THE PAST USING HDM CHALLENGE MODELS TO UNDERSTAND MECHANISTIC DETAILS IN ALLERGIC INFLAMMATION AND AIRWAY HYPERRESPONSIVENESS (AHR), THERE HAS BEEN NO STUDY ON REPROGRAMMING OF LUNG OR AIRWAYS MEDIATED THROUGH EPIGENETIC MECHANISMS IN RESPONSE TO AN ACUTE HDM EXPOSURE. MALE MICE, 6 WEEKS OF AGE, WERE ADMINISTRATED HDM EXTRACTS OR SALINE AT DAYS 1, 14, AND 21. EXPOSURE OF MICE TO HDM EXTRACTS CAUSED SIGNIFICANT AIRWAY INFLAMMATION AND INCREASED AHR. THESE HDM-CHALLENGED MICE ALSO EXHIBITED A CHANGE IN GLOBAL DNA METHYLATION AS COMPARED WITH SALINE-EXPOSED (CONTROL) MICE. NEXT, BY EMPLOYING METHYLATION-SENSITIVE RESTRICTION FINGERPRINTING, WE IDENTIFIED A SET OF GENES, SHOWING ABERRANT METHYLATION STATUS, ASSOCIATED WITH THE HDM-INDUCED AHR. THESE CANDIDATE GENES ARE KNOWN TO BE INVOLVED IN CAMP SIGNALING (PDE4 D), AKT-SIGNALING (AKT1 S1), ION TRANSPORT (TM6 SF1, POM121L2, AND SLC8A3), AND FATTY ACID METABOLISM (ACSL3). SLC8A3 AND ACSL3 WERE DOWN-REGULATED, WHEREAS PDE4 D, AKT1 S1, TM6 SF1, AND POM121L2 WERE UP-REGULATED IN THE MICE EXPOSED TO HDM. HENCE, OUR RESULTS SUGGEST THAT HDM EXPOSURE INDUCES A SERIES OF ABERRANT METHYLATED GENES THAT ARE POTENTIALLY IMPORTANT FOR THE DEVELOPMENT OF ALLERGIC AHR. 2013