1 3678 153 INFLAMMATION AND REGENERATION IN THE DENTIN-PULP COMPLEX: A DOUBLE-EDGED SWORD. DENTAL TISSUE INFECTION AND DISEASE RESULT IN ACUTE AND CHRONIC ACTIVATION OF THE INNATE IMMUNE RESPONSE, WHICH IS MEDIATED BY MOLECULAR AND CELLULAR SIGNALING. DIFFERENT CELL TYPES WITHIN THE DENTIN-PULP COMPLEX ARE ABLE TO DETECT INVADING BACTERIA AT ALL STAGES OF THE INFECTION. INDEED, AT RELATIVELY EARLY DISEASE STAGES, ODONTOBLASTS WILL RESPOND TO BACTERIAL COMPONENTS, AND AS THE DISEASE PROGRESSES, CORE PULPAL CELLS INCLUDING FIBROBLASTS, STEMS CELLS, ENDOTHELIAL CELLS, AND IMMUNE CELLS WILL BECOME INVOLVED. PATTERN RECOGNITION RECEPTORS, SUCH AS TOLL-LIKE RECEPTORS EXPRESSED ON THESE CELL TYPES, ARE RESPONSIBLE FOR DETECTING BACTERIAL COMPONENTS, AND THEIR LIGAND BINDING LEADS TO THE ACTIVATION OF THE NUCLEAR FACTOR-KAPPA B AND P38 MITOGEN-ACTIVATED PROTEIN (MAP) KINASE INTRACELLULAR SIGNALING CASCADES. SUBSEQUENT NUCLEAR TRANSLOCATION OF THE TRANSCRIPTION FACTOR SUBUNITS FROM THESE PATHWAYS WILL LEAD TO PROINFLAMMATORY MEDIATOR EXPRESSION, INCLUDING INCREASES IN CYTOKINES AND CHEMOKINES, WHICH TRIGGER HOST CELLULAR DEFENSE MECHANISMS. THE COMPLEX MOLECULAR SIGNALING WILL RESULT IN THE RECRUITMENT OF IMMUNE SYSTEM CELLS TARGETED AT COMBATING THE INVADING MICROBES; HOWEVER, THE TRAFFICKING AND ANTIBACTERIAL ACTIVITY OF THESE CELLS CAN LEAD TO COLLATERAL TISSUE DAMAGE. RECENT EVIDENCE SUGGESTS THAT IF INFLAMMATION IS RESOLVED RELATIVELY LOW LEVELS OF PROINFLAMMATORY MEDIATORS MAY PROMOTE TISSUE REPAIR, WHEREAS IF CHRONIC INFLAMMATION ENSUES REPAIR MECHANISMS BECOME INHIBITED. THUS, THE EFFECTS OF MEDIATORS ARE TEMPORAL CONTEXT DEPENDENT. ALTHOUGH CONTAINMENT AND REMOVAL OF THE INFECTION ARE KEYS TO ENABLE DENTAL TISSUE REPAIR, IT IS FEASIBLE THAT THE DEVELOPMENT OF ANTI-INFLAMMATORY AND IMMUNOMODULATORY APPROACHES, BASED ON MOLECULAR, EPIGENETIC, AND PHOTOBIOMODULATORY TECHNOLOGIES, MAY ALSO BE BENEFICIAL FOR FUTURE ENDODONTIC TREATMENTS. 2014 2 5720 30 SIRTUINS LINK INFLAMMATION AND METABOLISM. SIRTUINS (SIRT), FIRST DISCOVERED IN YEAST AS NAD+ DEPENDENT EPIGENETIC AND METABOLIC REGULATORS, HAVE COMPARABLE ACTIVITIES IN HUMAN PHYSIOLOGY AND DISEASE. MOUNTING EVIDENCE SUPPORTS THAT THE SEVEN-MEMBER MAMMALIAN SIRTUIN FAMILY (SIRT1-7) GUARD HOMEOSTASIS BY SENSING BIOENERGY NEEDS AND RESPONDING BY MAKING ALTERATIONS IN THE CELL NUTRIENTS. SIRTUINS PLAY A CRITICAL ROLE IN RESTORING HOMEOSTASIS DURING STRESS RESPONSES. INFLAMMATION IS DESIGNED TO "DEFEND AND MEND" AGAINST THE INVADING ORGANISMS. EMERGING EVIDENCE SUPPORTS THAT METABOLISM AND BIOENERGY REPROGRAMMING DIRECT THE SEQUENTIAL COURSE OF INFLAMMATION; FAILURE OF HOMEOSTASIS RETRIEVAL RESULTS IN MANY CHRONIC AND ACUTE INFLAMMATORY DISEASES. ANABOLIC GLYCOLYSIS QUICKLY INDUCED (COMPARED TO OXIDATIVE PHOSPHORYLATION) FOR ROS AND ATP GENERATION IS NEEDED FOR IMMUNE ACTIVATION TO "DEFEND" AGAINST INVADING MICROORGANISMS. LIPOLYSIS/FATTY ACID OXIDATION, ESSENTIAL FOR CELLULAR PROTECTION/HIBERNATION AND CELL SURVIVAL IN ORDER TO "MEND," LEADS TO IMMUNE REPRESSION. ACUTE/CHRONIC INFLAMMATIONS ARE LINKED TO ALTERED GLYCOLYSIS AND FATTY ACID OXIDATION, AT LEAST IN PART, BY NAD+ DEPENDENT FUNCTION OF SIRTUINS. THERAPEUTICALLY TARGETING SIRTUINS MAY PROVIDE A NEW CLASS OF INFLAMMATION AND IMMUNE REGULATORS. THIS REVIEW DISCUSSES HOW SIRTUINS INTEGRATE METABOLISM, BIOENERGETICS, AND IMMUNITY DURING INFLAMMATION AND HOW SIRTUIN-DIRECTED TREATMENT IMPROVES OUTCOME IN CHRONIC INFLAMMATORY DISEASES AND IN THE EXTREME STRESS RESPONSE OF SEPSIS. 2016 3 6365 36 THE ROLE OF METABOLIC DYSFUNCTION IN T-CELL EXHAUSTION DURING CHRONIC VIRAL INFECTION. T CELLS ARE IMPORTANT COMPONENTS OF ADAPTIVE IMMUNITY THAT PROTECT THE HOST AGAINST INVADING PATHOGENS DURING INFECTION. UPON RECOGNIZING THE ACTIVATION SIGNALS, NAIVE AND/OR MEMORY T CELLS WILL INITIATE CLONAL EXPANSION, TRIGGER DIFFERENTIATION INTO EFFECTOR POPULATIONS AND TRAFFIC TO THE INFLAMED SITES TO ELIMINATE PATHOGENS. HOWEVER, IN CHRONIC VIRAL INFECTIONS, SUCH AS THOSE CAUSED BY HUMAN IMMUNODEFICIENCY VIRUS (HIV), HEPATITIS B AND C (HBV AND HCV), T CELLS EXHIBIT IMPAIRED FUNCTION AND BECOME DIFFICULT TO CLEAR PATHOGENS IN A STATE KNOWN AS T-CELL EXHAUSTION. THE ACTIVATION AND FUNCTION PERSISTENCE OF T CELLS DEMAND FOR DYNAMIC CHANGES IN CELLULAR METABOLISM TO MEET THEIR BIOENERGETIC AND BIOSYNTHETIC DEMANDS, ESPECIALLY THE AUGMENTATION OF AEROBIC GLYCOLYSIS, WHICH NOT ONLY PROVIDE EFFICIENT ENERGY GENERATION, BUT ALSO FUEL MULTIPLE BIOCHEMICAL INTERMEDIATES THAT ARE ESSENTIAL FOR NUCLEOTIDE, AMINO ACID, FATTY ACID SYNTHESIS AND MITOCHONDRIA FUNCTION. CHANGES IN CELLULAR METABOLISM ALSO AFFECT THE FUNCTION OF EFFECTORS T CELLS THROUGH MODIFYING EPIGENETIC SIGNATURES. IT IS WIDELY ACCEPTED THAT THE DYSFUNCTION OF T CELL METABOLISM CONTRIBUTES GREATLY TO T-CELL EXHAUSTION. HERE, WE REVIEWED RECENT FINDINGS ON T CELLS METABOLISM UNDER CHRONIC VIRAL INFECTION, SEEKING TO REVEAL THE ROLE OF METABOLIC DYSFUNCTION PLAYED IN T-CELL EXHAUSTION. 2022 4 6506 27 TRAINED INNATE IMMUNITY NOT ALWAYS AMICABLE. THE CONCEPT OF „TRAINED INNATE IMMUNITY" IS UNDERSTOOD AS THE ABILITY OF INNATE IMMUNE CELLS TO REMEMBER INVADING AGENTS AND TO RESPOND NONSPECIFICALLY TO REINFECTION WITH INCREASED STRENGTH. TRAINED IMMUNITY IS ORCHESTRATED BY EPIGENETIC MODIFICATIONS LEADING TO CHANGES IN GENE EXPRESSION AND CELL PHYSIOLOGY. ALTHOUGH THIS PHENOMENON WAS ORIGINALLY SEEN MAINLY AS A BENEFICIAL EFFECT, SINCE IT CONFERS BROAD IMMUNOLOGICAL PROTECTION, ENHANCED IMMUNE RESPONSE OF REPROGRAMMED INNATE IMMUNE CELLS MIGHT RESULT IN THE DEVELOPMENT OR PERSISTENCE OF CHRONIC METABOLIC, AUTOIMMUNE OR NEUROINFALMMATORY DISORDERS. THIS PAPER OVERVIEWS SEVERAL EXAMPLES WHERE THE INDUCTION OF TRAINED IMMUNITY MAY BE ESSENTIAL IN THE DEVELOPMENT OF DISEASES CHARACTERIZED BY FLAWED INNATE IMMUNE RESPONSE. 2019 5 3544 33 IMMUNOMETABOLIC CONTROL OF TRAINED IMMUNITY. INNATE IMMUNE CELLS CAN ADOPT LONG-TERM INFLAMMATORY PHENOTYPES FOLLOWING BRIEF ENCOUNTERS WITH EXOGENOUS (MICROBIAL) OR ENDOGENOUS STIMULI. THIS PHENOMENON IS NAMED TRAINED IMMUNITY AND CAN IMPROVE HOST DEFENSE AGAINST (RECURRENT) INFECTIONS. IN CONTRAST, TRAINED IMMUNITY CAN ALSO BE MALADAPTIVE IN THE CONTEXT OF CHRONIC INFLAMMATORY DISORDERS, SUCH AS ATHEROSCLEROSIS. KEY TO FUTURE THERAPEUTIC EXPLOITATION OF THIS MECHANISM IS THOROUGH KNOWLEDGE OF THE MECHANISMS DRIVING TRAINED IMMUNITY, WHICH CAN BE USED AS PHARMACOLOGICAL TARGETS. THESE MECHANISMS INCLUDE PROFOUND CHANGES IN INTRACELLULAR METABOLISM, WHICH ARE CLOSELY INTERTWINED WITH EPIGENETIC REPROGRAMMING AT THE LEVEL OF HISTONE MODIFICATIONS. GLYCOLYSIS, GLUTAMINE REPLENISHMENT OF THE TRICARBOXYLIC ACID CYCLE WITH ACCUMULATION OF FUMARATE, AND THE MEVALONATE PATHWAY HAVE ALL BEEN IDENTIFIED AS CRITICAL PATHWAYS FOR TRAINED IMMUNITY IN MONOCYTES AND MACROPHAGES. IN THIS REVIEW, WE PROVIDE A STATE-OF-THE-ART OVERVIEW OF HOW THESE METABOLIC PATHWAYS INTERACT WITH EPIGENETIC PROGRAMS TO DEVELOP TRAINED IMMUNITY. 2021 6 1876 38 EMERGING ROLES FOR EPIGENETIC PROGRAMMING IN THE CONTROL OF INFLAMMATORY SIGNALING INTEGRATION IN HEATH AND DISEASE. MACROPHAGES AND DENDRITIC CELLS INITIATE THE INNATE IMMUNE RESPONSE TO INFECTION AND INJURY AND CONTRIBUTE TO INFLAMMATORY SIGNALING TO MAINTAIN THE HOMEOSTASIS OF VARIOUS TISSUES, WHICH INCLUDES RESIDENT MACROPHAGES FOR THE ELIMINATION OF INVADING MICROORGANISMS AND TISSUE DAMAGE. INAPPROPRIATE INFLAMMATORY SIGNALING CAN LEAD TO PERSISTENT INFLAMMATION AND FURTHER DEVELOP INTO AUTOIMMUNE AND INFLAMMATION-ASSOCIATED DISEASES. INFLAMMATORY SIGNALING PATHWAYS HAVE BEEN WELL CHARACTERIZED, BUT HOW THESE SIGNALING PATHWAYS ARE CONVERTED INTO SUSTAINED AND DIVERSE PATTERNS OF EXPRESSION OF CYTOKINES, CHEMOKINES, AND OTHER GENES IN RESPONSE TO ENVIRONMENTAL CHALLENGES IS UNCLEAR. EMERGING EVIDENCE SUGGESTS THE IMPORTANT ROLE OF EPIGENETIC MECHANISMS IN FINELY TUNING THE OUTCOME OF THE HOST INNATE IMMUNE RESPONSE. AN UNDERSTANDING OF EPIGENETIC REGULATION OF INNATE IMMUNE CELL IDENTITY AND FUNCTION WILL ENABLE THE IDENTIFICATION OF THE MECHANISM BETWEEN GENE-SPECIFIC HOST DEFENSES AND INFLAMMATORY DISEASE AND WILL ALSO ALLOW FOR EXPLORATION OF THE PROGRAM OF INNATE IMMUNE MEMORY IN HEALTH AND DISEASE. THIS INFORMATION COULD BE USED TO DEVELOP THERAPEUTIC AGENTS TO ENHANCE THE HOST RESPONSE, PREVENTING CHRONIC INFLAMMATION THROUGH PRESERVING TISSUES AND SIGNALING INTEGRITY. 2017 7 6181 35 THE IMMUNE FUNCTIONS OF KERATINOCYTES IN SKIN WOUND HEALING. AS THE MOST DOMINANT CELL TYPE IN THE SKIN, KERATINOCYTES PLAY CRITICAL ROLES IN WOUND REPAIR NOT ONLY AS STRUCTURAL CELLS BUT ALSO EXERTING IMPORTANT IMMUNE FUNCTIONS. THIS REVIEW FOCUSES ON THE COMMUNICATIONS BETWEEN KERATINOCYTES AND IMMUNE CELLS IN WOUND HEALING, WHICH ARE MEDIATED BY VARIOUS CYTOKINES, CHEMOKINES, AND EXTRACELLULAR VESICLES. KERATINOCYTES CAN ALSO DIRECTLY INTERACT WITH T CELLS VIA ANTIGEN PRESENTATION. MOREOVER, KERATINOCYTES PRODUCE ANTIMICROBIAL PEPTIDES THAT CAN DIRECTLY KILL THE INVADING PATHOGENS AND CONTRIBUTE TO WOUND REPAIR IN MANY ASPECTS. WE ALSO REVIEWED THE EPIGENETIC MECHANISMS KNOWN TO REGULATE KERATINOCYTE IMMUNE FUNCTIONS, INCLUDING HISTONE MODIFICATIONS, NON-PROTEIN-CODING RNAS (E.G., MICRORNAS, AND LONG NONCODING RNAS), AND CHROMATIN DYNAMICS. LASTLY, WE SUMMARIZED THE CURRENT EVIDENCE ON THE DYSREGULATED IMMUNE FUNCTIONS OF KERATINOCYTES IN CHRONIC NONHEALING WOUNDS. BASED ON THEIR CRUCIAL IMMUNE FUNCTIONS IN SKIN WOUND HEALING, WE PROPOSE THAT KERATINOCYTES SIGNIFICANTLY CONTRIBUTE TO THE PATHOGENESIS OF CHRONIC WOUND INFLAMMATION. WE HOPE THIS REVIEW WILL TRIGGER AN INTEREST IN INVESTIGATING THE IMMUNE ROLES OF KERATINOCYTES IN CHRONIC WOUND PATHOLOGY, WHICH MAY OPEN UP NEW AVENUES FOR DEVELOPING INNOVATIVE WOUND TREATMENTS. 2020 8 6502 32 TRAINED IMMUNITY: LONG-TERM ADAPTATION IN INNATE IMMUNE RESPONSES. ADAPTIVE IMMUNE RESPONSES ARE CHARACTERIZED BY ANTIGEN SPECIFICITY AND INDUCTION OF LIFELONG IMMUNOLOGIC MEMORY. RECENTLY, IT HAS BEEN REPORTED THAT INNATE IMMUNE CELLS CAN ALSO BUILD IMMUNE MEMORY CHARACTERISTICS-A PROCESS TERMED TRAINED IMMUNITY. TRAINED IMMUNITY DESCRIBES THE PERSISTENT HYPERRESPONSIVE PHENOTYPE THAT INNATE IMMUNE CELLS CAN DEVELOP AFTER BRIEF STIMULATION. PATHOGENIC STIMULI SUCH AS MICROORGANISMS, AND ALSO ENDOGENOUS MOLECULES INCLUDING URIC ACID, OXIDIZED LDL (LOW-DENSITY LIPOPROTEIN), AND CATECHOLAMINES, ARE CAPABLE OF INDUCING MEMORY IN MONOCYTES AND MACROPHAGES. WHILE TRAINED IMMUNITY PROVIDES FAVORABLE CROSS-PROTECTION IN THE CONTEXT OF INFECTIOUS DISEASES, THE HEIGHTENED IMMUNE RESPONSE CAN BE MALADAPTIVE IN DISEASES DRIVEN BY CHRONIC SYSTEMIC INFLAMMATION, SUCH AS ATHEROSCLEROSIS. TRAINED IMMUNITY IS MAINTAINED BY DISTINCT EPIGENETIC AND METABOLIC MECHANISMS AND PERSISTS FOR AT LEAST SEVERAL MONTHS IN VIVO DUE TO REPROGRAMMING OF MYELOID PROGENITOR CELLS. ADDITIONALLY, CERTAIN NONIMMUNE CELLS ARE ALSO FOUND TO EXHIBIT TRAINED IMMUNITY CHARACTERISTICS. THUS, TRAINED IMMUNITY PRESENTS AN EXCITING FRAMEWORK TO DEVELOP NEW APPROACHES TO VACCINATION AND ALSO NOVEL PHARMACOLOGICAL TARGETS IN THE TREATMENT OF INFLAMMATORY DISEASES. 2021 9 2563 39 EPIGENETICS IN TUBERCULOSIS: IMMUNOMODULATION OF HOST IMMUNE RESPONSE. TUBERCULOSIS IS A STERN, DIFFICULT TO TREAT CHRONIC INFECTION CAUSED BY ACID-FAST BACILLI THAT TEND TO TAKE A LONG TIME TO BE ERADICATED FROM THE HOST'S ENVIRONMENT. IT REQUIRES THE ACTION OF BOTH INNATE AND ADAPTIVE IMMUNE SYSTEMS BY THE HOST. THERE ARE VARIOUS PATTERN RECOGNITION RECEPTORS PRESENT ON IMMUNE CELLS, WHICH RECOGNIZE FOREIGN PATHOGENS OR ITS PRODUCT AND TRIGGER THE IMMUNE RESPONSE. THE EPIGENETIC MODIFICATION PLAYS A CRUCIAL ROLE IN TRIGGERING THE SUSCEPTIBILITY OF THE HOST TOWARDS THE PATHOGEN AND ACTIVATING THE HOST'S IMMUNE SYSTEM AGAINST THE INVADING PATHOGEN. IT ALTERS THE GENE EXPRESSION MODIFYING THE GENETIC MATERIAL OF THE HOST'S CELL. EPIGENETIC MODIFICATION SUCH AS HISTONE ACETYLATION, ALTERATION IN NON-CODING RNA, DNA METHYLATION AND ALTERATION IN MIRNA HAS BEEN STUDIED FOR THEIR INFLUENCE ON THE PATHOPHYSIOLOGY OF TUBERCULOSIS TO CONTROL THE SPREAD OF INFECTION. DESPITE SEVERAL STUDIES BEING CONDUCTED, MANY GAPS STILL EXIST. HEREIN, WE DISCUSS THE IMMUNOPATHOPHYSIOLOGICAL MECHANISM OF TUBERCULOSIS, THE ESSENTIALS OF EPIGENETICS AND THE RECENT ENCROACHMENT OF EPIGENETICS IN THE FIELD OF TUBERCULOSIS AND ITS INFLUENCE ON THE OUTCOME AND PATHOPHYSIOLOGY OF THE INFECTION. 2022 10 111 40 A ROLE FOR G-PROTEIN COUPLED ESTROGEN RECEPTOR (GPER) IN ESTROGEN-INDUCED CARCINOGENESIS: DYSREGULATED GLANDULAR HOMEOSTASIS, SURVIVAL AND METASTASIS. MECHANISMS OF CARCINOGENESIS BY ESTROGEN CENTER ON ITS MITOGENIC AND GENOTOXIC POTENTIAL ON TUMOR TARGET CELLS. THESE MODELS SUGGEST THAT ESTROGEN RECEPTOR (ER) SIGNALING PROMOTES EXPANSION OF THE TRANSFORMED POPULATION AND THAT SUBSEQUENT ACCUMULATION OF SOMATIC MUTATIONS THAT DRIVE CANCER PROGRESSION OCCUR VIA METABOLIC ACTIVATION OF CATHECOL ESTROGENS OR BY EPIGENETIC MECHANISMS. RECENT FINDINGS THAT GPER IS LINKED TO OBESITY, VASCULAR PATHOLOGY AND IMMUNOSUPPRESSION, KEY EVENTS IN THE DEVELOPMENT OF METABOLIC SYNDROME AND INTRA-TISSULAR ESTROGEN SYNTHESIS, PROVIDES AN ALTERNATE VIEW OF ESTROGEN-INDUCED CARCINOGENESIS. CONSISTENT WITH THIS CONCEPT, GPER IS DIRECTLY ASSOCIATED WITH CLINICOPATHOLOGICAL INDICES THAT PREDICT CANCER PROGRESSION AND POOR SURVIVAL IN BREAST AND GYNECOLOGICAL CANCERS. MOREOVER, GPER MANIFESTS CELL BIOLOGICAL RESPONSES AND A MICROENVIRONMENT CONDUCIVE FOR TUMOR DEVELOPMENT AND CANCER PROGRESSION, REGULATING CELLULAR RESPONSES ASSOCIATED WITH GLANDULAR HOMEOSTASIS AND SURVIVAL, INVADING SURROUNDING TISSUE AND ATTRACTING A VASCULAR SUPPLY. THUS, THE CELLULAR ACTIONS ATTRIBUTED TO GPER FIT WELL WITH THE KNOWN MOLECULAR MECHANISMS OF G-PROTEIN COUPLED RECEPTORS, GPCRS, NAMELY, THEIR ABILITY TO TRANSACTIVATE INTEGRINS AND EGF RECEPTORS AND ALTER THE INTERACTION BETWEEN GLANDULAR EPITHELIA AND THEIR EXTRACELLULAR ENVIRONMENT, AFFECTING EPITHELIAL-TO-MESENCHYMAL TRANSITION (EMT) AND ALLOWING FOR TUMOR CELL SURVIVAL AND DISSEMINATION. THIS PERSPECTIVE REVIEWS THE MOLECULAR AND CELLULAR RESPONSES MANIFESTED BY GPER AND EVALUATES ITS CONTRIBUTION TO FEMALE REPRODUCTIVE CANCERS AS DISEASES THAT PROGRESS AS A RESULT OF DYSREGULATED GLANDULAR HOMEOSTASIS RESULTING IN CHRONIC INFLAMMATION AND METASTASIS. THIS REVIEW IS ORGANIZED IN SECTIONS AS FOLLOWS: I) A BRIEF SYNOPSIS OF THE CURRENT STATE OF KNOWLEDGE REGARDING ESTROGEN-INDUCED CARCINOGENESIS, II) A REVIEW OF EVIDENCE FROM CLINICAL AND ANIMAL-BASED STUDIES THAT SUPPORT A ROLE FOR GPER IN CANCER PROGRESSION, AND III) A MECHANISTIC FRAMEWORK DESCRIBING HOW GPER-MEDIATED ESTROGEN ACTION MAY INFLUENCE THE TUMOR AND ITS MICROENVIRONMENT. 2018 11 3732 33 INNATE IMMUNE MEMORY AND THE HOST RESPONSE TO INFECTION. UNLIKE THE ADAPTIVE IMMUNE SYSTEM, THE INNATE IMMUNE SYSTEM HAS CLASSICALLY BEEN CHARACTERIZED AS BEING DEVOID OF MEMORY FUNCTIONS. HOWEVER, RECENT RESEARCH SHOWS THAT INNATE MYELOID AND LYMPHOID CELLS HAVE THE ABILITY TO RETAIN MEMORY OF PRIOR PATHOGEN EXPOSURE AND BECOME PRIMED TO ELICIT A ROBUST, BROAD-SPECTRUM RESPONSE TO SUBSEQUENT INFECTION. THIS PHENOMENON HAS BEEN TERMED INNATE IMMUNE MEMORY OR TRAINED IMMUNITY. INNATE IMMUNE MEMORY IS INDUCED VIA ACTIVATION OF PATTERN RECOGNITION RECEPTORS AND THE ACTIONS OF CYTOKINES ON HEMATOPOIETIC PROGENITORS AND STEM CELLS IN BONE MARROW AND INNATE LEUKOCYTES IN THE PERIPHERY. THE TRAINED PHENOTYPE IS INDUCED AND SUSTAINED VIA EPIGENETIC MODIFICATIONS THAT REPROGRAM TRANSCRIPTIONAL PATTERNS AND METABOLISM. THESE MODIFICATIONS AUGMENT ANTIMICROBIAL FUNCTIONS, SUCH AS LEUKOCYTE EXPANSION, CHEMOTAXIS, PHAGOCYTOSIS, AND MICROBIAL KILLING, TO FACILITATE AN AUGMENTED HOST RESPONSE TO INFECTION. ALTERNATIVELY, INNATE IMMUNE MEMORY MAY CONTRIBUTE TO THE PATHOGENESIS OF CHRONIC DISEASES, SUCH AS ATHEROSCLEROSIS AND ALZHEIMER'S DISEASE. 2022 12 6452 30 THERAPIES TARGETING TRAINED IMMUNE CELLS IN INFLAMMATORY AND AUTOIMMUNE DISEASES. THE CONCEPT OF TRAINED IMMUNITY HAS RECENTLY EMERGED AS A MECHANISM CONTRIBUTING TO SEVERAL IMMUNE MEDIATED INFLAMMATORY CONDITIONS. TRAINED IMMUNITY IS DEFINED BY THE IMMUNOLOGICAL MEMORY DEVELOPED IN INNATE IMMUNE CELLS AFTER A PRIMARY NON-SPECIFIC STIMULUS THAT, IN TURN, PROMOTES A HEIGHTENED INFLAMMATORY RESPONSE UPON A SECONDARY CHALLENGE. THE MOST CHARACTERISTIC CHANGES ASSOCIATED TO THIS PROCESS INVOLVE THE REWIRING OF CELL METABOLISM AND EPIGENETIC REPROGRAMMING. UNDER PHYSIOLOGICAL CONDITIONS, THE ROLE OF TRAINED IMMUNE CELLS ENSURES A PROMPT RESPONSE. THIS ACTION IS LIMITED BY EFFECTIVE RESOLUTION OF INFLAMMATION AND TISSUE REPAIR IN ORDER TO RESTORE HOMEOSTASIS. HOWEVER, UNRESTRAINED ACTIVATION OF INNATE IMMUNE CELLS CONTRIBUTES TO THE DEVELOPMENT OF CHRONIC INFLAMMATION AND TISSUE DESTRUCTION THROUGH THE SECRETION OF INFLAMMATORY CYTOKINES, PROTEASES AND GROWTH FACTORS. THEREFORE, INTERVENTIONS AIMED AT REVERSING THE CHANGES INDUCED BY TRAINED IMMUNITY PROVIDE POTENTIAL THERAPEUTIC APPROACHES TO TREAT INFLAMMATORY AND AUTOIMMUNE DISEASES LIKE RHEUMATOID ARTHRITIS (RA). WE REVIEW CELLULAR APPROACHES THAT TARGET METABOLISM AND THE EPIGENETIC REPROGRAMMING OF DENDRITIC CELLS, MACROPHAGES, NATURAL KILLER CELLS, AND OTHER TRAINED CELLS IN THE CONTEXT OF AUTOIMMUNE INFLAMMATORY DISEASES. 2020 13 1310 25 DEFINING TRAINED IMMUNITY AND ITS ROLE IN HEALTH AND DISEASE. IMMUNE MEMORY IS A DEFINING FEATURE OF THE ACQUIRED IMMUNE SYSTEM, BUT ACTIVATION OF THE INNATE IMMUNE SYSTEM CAN ALSO RESULT IN ENHANCED RESPONSIVENESS TO SUBSEQUENT TRIGGERS. THIS PROCESS HAS BEEN TERMED 'TRAINED IMMUNITY', A DE FACTO INNATE IMMUNE MEMORY. RESEARCH IN THE PAST DECADE HAS POINTED TO THE BROAD BENEFITS OF TRAINED IMMUNITY FOR HOST DEFENCE BUT HAS ALSO SUGGESTED POTENTIALLY DETRIMENTAL OUTCOMES IN IMMUNE-MEDIATED AND CHRONIC INFLAMMATORY DISEASES. HERE WE DEFINE 'TRAINED IMMUNITY' AS A BIOLOGICAL PROCESS AND DISCUSS THE INNATE STIMULI AND THE EPIGENETIC AND METABOLIC REPROGRAMMING EVENTS THAT SHAPE THE INDUCTION OF TRAINED IMMUNITY. 2020 14 1349 34 DETERMINANTS OF INNATE IMMUNITY IN VISCERAL LEISHMANIASIS AND THEIR IMPLICATION IN VACCINE DEVELOPMENT. LEISHMANIASIS IS ENDEMIC TO THE TROPICAL AND SUBTROPICAL REGIONS OF THE WORLD AND IS TRANSMITTED BY THE BITE OF AN INFECTED SAND FLY. THE MULTIFACETED INTERACTIONS BETWEEN LEISHMANIA, THE HOST INNATE IMMUNE CELLS, AND THE ADAPTIVE IMMUNITY DETERMINE THE SEVERITY OF PATHOGENESIS AND DISEASE DEVELOPMENT. LEISHMANIA PARASITES ESTABLISH A CHRONIC INFECTION BY SUBVERSION AND ATTENUATION OF THE MICROBICIDAL FUNCTIONS OF PHAGOCYTIC INNATE IMMUNE CELLS SUCH AS NEUTROPHILS, MACROPHAGES AND DENDRITIC CELLS (DCS). OTHER INNATE CELLS SUCH AS INFLAMMATORY MONOCYTES, MAST CELLS AND NK CELLS, ALSO CONTRIBUTE TO RESISTANCE AND/OR SUSCEPTIBILITY TO LEISHMANIA INFECTION. IN ADDITION TO THE CYTOKINE/CHEMOKINE SIGNALS FROM THE INNATE IMMUNE CELLS, RECENT STUDIES IDENTIFIED THE SUBTLE SHIFTS IN THE METABOLIC PATHWAYS OF THE INNATE CELLS THAT ACTIVATE DISTINCT IMMUNE SIGNAL CASCADES. THE NEXUS BETWEEN METABOLIC PATHWAYS, EPIGENETIC REPROGRAMMING AND THE IMMUNE SIGNALING CASCADES THAT DRIVE THE DIVERGENT INNATE IMMUNE RESPONSES, REMAINS TO BE FULLY UNDERSTOOD IN LEISHMANIA PATHOGENESIS. FURTHER, DEVELOPMENT OF SAFE AND EFFICACIOUS VACCINES AGAINST LEISHMANIASIS REQUIRES A BROADER UNDERSTANDING OF THE EARLY INTERACTIONS BETWEEN THE PARASITES AND INNATE IMMUNE CELLS. IN THIS REVIEW WE FOCUS ON THE CURRENT UNDERSTANDING OF THE SPECIFIC ROLE OF INNATE IMMUNE CELLS, THE METABOLOMIC AND EPIGENETIC REPROGRAMMING AND IMMUNE REGULATION THAT OCCURS DURING VISCERAL LEISHMANIASIS, AND THE STRATEGIES USED BY THE PARASITE TO EVADE AND MODULATE HOST IMMUNITY. WE HIGHLIGHT HOW SUCH PATHWAYS COULD BE EXPLOITED IN THE DEVELOPMENT OF SAFE AND EFFICACIOUS LEISHMANIA VACCINES. 2021 15 3734 38 INNATE IMMUNE MEMORY IN MONOCYTES AND MACROPHAGES: THE POTENTIAL THERAPEUTIC STRATEGIES FOR ATHEROSCLEROSIS. ATHEROSCLEROSIS IS A COMPLEX METABOLIC DISEASE CHARACTERIZED BY THE DYSFUNCTION OF LIPID METABOLISM AND CHRONIC INFLAMMATION IN THE INTIMAL SPACE OF THE VESSEL. AS THE MOST ABUNDANT INNATE IMMUNE CELLS, MONOCYTE-DERIVED MACROPHAGES PLAY A PIVOTAL ROLE IN THE INFLAMMATORY RESPONSE, CHOLESTEROL METABOLISM, AND FOAM CELL FORMATION. IN RECENT DECADES, IT HAS BEEN DEMONSTRATED THAT MONOCYTES AND MACROPHAGES CAN ESTABLISH INNATE IMMUNE MEMORY (ALSO TERMED TRAINED IMMUNITY) VIA ENDOGENOUS AND EXOGENOUS ATHEROGENIC STIMULI AND EXHIBIT A LONG-LASTING PROINFLAMMATORY PHENOTYPE. THE IMPORTANT CELLULAR METABOLISM PROCESSES, INCLUDING GLYCOLYSIS, OXIDATIVE PHOSPHORYLATION (OXPHOS), THE TRICARBOXYLIC ACID (TCA) CYCLE, FATTY ACID SYNTHESIS, AND CHOLESTEROL SYNTHESIS, ARE REPROGRAMMED. TRAINED MONOCYTES/MACROPHAGES WITH INNATE IMMUNE MEMORY CAN BE PERSISTENTLY HYPERACTIVATED AND CAN UNDERGO EXTENSIVE EPIGENETIC REWIRING, WHICH CONTRIBUTES TO THE PATHOPHYSIOLOGICAL DEVELOPMENT OF ATHEROSCLEROSIS VIA INCREASED PROINFLAMMATORY CYTOKINE PRODUCTION AND LIPID ACCUMULATION. HERE, WE PROVIDE AN OVERVIEW OF THE REGULATION OF CELLULAR METABOLIC PROCESSES AND EPIGENETIC MODIFICATIONS OF INNATE IMMUNE MEMORY IN MONOCYTES/MACROPHAGES AS WELL AS THE POTENTIAL ENDOGENOUS AND EXOGENOUS STIMULATIONS INVOLVED IN THE PROGRESSION OF ATHEROSCLEROSIS THAT HAVE BEEN REPORTED RECENTLY. THESE ELUCIDATIONS MIGHT BE BENEFICIAL FOR FURTHER UNDERSTANDING INNATE IMMUNE MEMORY AND THE DEVELOPMENT OF THERAPEUTIC STRATEGIES FOR INFLAMMATORY DISEASES AND ATHEROSCLEROSIS. 2022 16 2342 33 EPIGENETIC REGULATION OF MACROPHAGE POLARIZATION AND FUNCTION. MACROPHAGE POLARIZATION REFERS TO DEVELOPMENT OF A SPECIFIC PHENOTYPE IMPORTANT FOR TISSUE HOMEOSTASIS OR HOST DEFENSE IN RESPONSE TO ENVIRONMENTAL CUES. ENVIRONMENTAL FACTORS THAT INDUCE MACROPHAGE POLARIZATION INCLUDE CYTOKINES AND MICROBIAL FACTORS PRODUCED BY PATHOGENS OR COMMENSAL MICROBIOTA. SIGNALING PATHWAYS UTILIZED BY THESE POLARIZING FACTORS HAVE BEEN WELL CHARACTERIZED, BUT IT IS LESS CLEAR HOW SIGNALS ARE CONVERTED INTO COMPLEX AND SUSTAINED PATTERNS OF GENE EXPRESSION, AND HOW MACROPHAGES ARE REPROGRAMMED DURING POLARIZATION TO ALTER THEIR RESPONSES TO SUBSEQUENT ENVIRONMENTAL CHALLENGES. EMERGING EVIDENCE, REVIEWED HERE, SUGGESTS AN IMPORTANT ROLE FOR EPIGENETIC MECHANISMS IN MODULATING AND TRANSMITTING SIGNALS DURING MACROPHAGE POLARIZATION AND REPROGRAMMING. DEEPER UNDERSTANDING OF EPIGENETIC REGULATION OF MACROPHAGE PHENOTYPE WILL ENABLE DEVELOPMENT OF GENE-SPECIFIC THERAPEUTIC APPROACHES TO ENHANCE HOST DEFENSE WHILE PRESERVING TISSUE INTEGRITY AND PREVENTING CHRONIC INFLAMMATORY DISEASES. 2013 17 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 18 6494 30 TRAINED IMMUNITY AS A NOVEL THERAPEUTIC STRATEGY. RECENT STUDIES HAVE SHOWN THAT UPON CERTAIN VACCINATIONS OR INFECTIONS HUMAN INNATE IMMUNE CELLS CAN UNDERGO EXTENSIVE METABOLIC AND EPIGENETIC REPROGRAMMING, WHICH RESULTS IN ENHANCED IMMUNE RESPONSES UPON HETEROLOGOUS RE-INFECTION, A PROCESS TERMED TRAINED IMMUNITY. TRAINED IMMUNITY HAS ALSO BEEN SHOWN TO BE INAPPROPRIATELY ACTIVATED IN INFLAMMATORY DISEASES. THIS PROVIDES THE POTENTIAL FOR IDENTIFYING NOVEL THERAPEUTIC TARGETS: POTENTIATION OF TRAINED IMMUNITY COULD PROTECT FROM SECONDARY INFECTIONS AND REVERSE IMMUNOTOLERANT STATES, WHILE INHIBITION OF TRAINED IMMUNITY MIGHT REDUCE EXCESSIVE IMMUNE ACTIVATION IN CHRONIC INFLAMMATORY CONDITIONS. BY TARGETING SPECIFIC MECHANISMS OF TRAINED IMMUNITY ON EITHER IMMUNOLOGIC, METABOLIC OR EPIGENETIC LEVEL, NOVEL THERAPEUTIC APPROACHES COULD BE DEVELOPED. 2018 19 6500 29 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 20 4535 32 MULTIPLE ROLES OF TOLL-LIKE RECEPTOR 4 IN COLORECTAL CANCER. TOLL-LIKE RECEPTOR (TLR) SIGNALING HAS BEEN IMPLICATED IN THE INFLAMMATORY RESPONSES IN INTESTINAL EPITHELIAL CELLS (IECS). SUCH INFLAMMATORY SIGNALS MEDIATE COMPLEX INTERACTIONS BETWEEN COMMENSAL BACTERIA AND TLRS AND ARE REQUIRED FOR IEC PROLIFERATION, IMMUNE RESPONSE, REPAIR, AND HOMEOSTASIS. THE UPREGULATION OF CERTAIN TLRS IN COLORECTAL CANCER (CRC) TISSUES SUGGESTS THAT TLRS MAY PLAY AN ESSENTIAL ROLE IN THE PROGNOSIS OF CHRONIC AND INFLAMMATORY DISEASES THAT ULTIMATELY CULMINATE IN CRC. HERE, WE PROVIDE A COMPREHENSIVE REVIEW OF THE LITERATURE ON THE INVOLVEMENT OF THE TLR PATHWAY IN THE INITIATION, PROGRESSION, AND METASTASIS OF CRC, AS WELL AS INHERITED GENETIC VARIATION AND EPIGENETIC REGULATION. THE DIFFERENTIAL EXPRESSION OF TLRS IN EPITHELIAL CELLS HAS ALSO BEEN DISCUSSED. IN PARTICULAR, WE EMPHASIZE THE PHYSIOLOGICAL ROLE OF TLR4 IN CRC DEVELOPMENT AND PATHOGENESIS, AND PROPOSE NOVEL AND PROMISING APPROACHES FOR CRC THERAPEUTICS WITH THE AID OF TLR LIGANDS. 2014