1 3373 129 HISTONE MODULATION BLOCKS TREG-INDUCED FOXP3 BINDING TO THE IL-2 PROMOTER OF VIRUS-SPECIFIC CD8(+) T CELLS FROM FELINE IMMUNODEFICIENCY VIRUS-INFECTED CATS. CD8(+) T CELLS ARE CRITICAL FOR CONTROLLING HIV INFECTION. DURING THE CHRONIC PHASE OF LENTIVIRAL INFECTION, CD8(+) T CELLS LOSE THEIR PROLIFERATIVE CAPACITY AND EXHIBIT IMPAIRED ANTIVIRAL FUNCTION. THIS LOSS OF CD8(+) T CELL FUNCTION IS DUE, IN PART, TO CD4(+)CD25(+) T REGULATORY (TREG) CELL-MEDIATED SUPPRESSION. OUR RESEARCH GROUP HAS DEMONSTRATED THAT LENTIVIRUS-ACTIVATED CD4(+)CD25(+) TREG CELLS INDUCE THE REPRESSIVE TRANSCRIPTION FACTOR FORKHEAD BOX P3 (FOXP3) IN AUTOLOGOUS CD8(+) T CELLS FOLLOWING CO-CULTURE. WE HAVE RECENTLY REPORTED THAT TREG-INDUCED FOXP3 BINDS THE INTERLEUKIN-2 (IL-2), INTERFERON-GAMMA (IFN- GAMMA), AND TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA) PROMOTERS IN VIRUS-SPECIFIC CD8(+) T CELLS. THESE DATA SUGGEST AN IMPORTANT ROLE OF FOXP3-MEDIATED CD8(+) T CELL DYSFUNCTION IN LENTIVIRAL INFECTION. TO ELUCIDATE THE MECHANISM OF THIS SUPPRESSION, WE PREVIOUSLY REPORTED THAT DECREASED METHYLATION FACILITATES FOXP3 BINDING IN MITOGEN-ACTIVATED CD8(+) T CELLS FROM FELINE IMMUNODEFICIENCY VIRUS (FIV)-INFECTED CATS. WE DEMONSTRATED THE REDUCED BINDING OF FOXP3 TO THE IL-2 PROMOTER BY INCREASING METHYLATION OF CD8(+) T CELLS. IN THE STUDIES PRESENTED HERE, WE ASK IF ANOTHER FORM OF EPIGENETIC MODULATION MIGHT ALLEVIATE FOXP3-MEDIATED SUPPRESSION IN CD8(+) T CELLS. WE HYPOTHESIZED THAT DECREASING HISTONE ACETYLATION IN VIRUS-SPECIFIC CD8(+) T CELLS WOULD DECREASE TREG-INDUCED FOXP3 BINDING TO THE IL-2 PROMOTER. INDEED, USING ANACARDIC ACID (AA), A KNOWN HISTONE ACETYL TRANSFERASE (HAT) INHIBITOR, WE DEMONSTRATE A REDUCTION IN FOXP3 BINDING TO THE IL-2 PROMOTER IN VIRUS-SPECIFIC CD8(+) T CELLS CO-CULTURED WITH AUTOLOGOUS TREG CELLS. THESE DATA IDENTIFY A NOVEL MECHANISM OF FOXP3-MEDIATED CD8(+) T CELL DYSFUNCTION DURING LENTIVIRAL INFECTION. 2018 2 6020 36 THE ATTENUATION OF RENAL FIBROSIS BY HISTONE DEACETYLASE INHIBITORS IS ASSOCIATED WITH THE PLASTICITY OF FOXP3(+)IL-17(+) T CELLS. BACKGROUND: THE HISTONE DEACETYLASE (HDAC) INHIBITOR, WHICH HAS POTENTIAL EFFECTS ON EPIGENETIC MODIFICATIONS, HAD BEEN REPORTED TO ATTENUATE RENAL FIBROSIS. CD4(+) FORKHEAD BOX P3 (FOXP3)(+) T REGULATORY (TREG) CELLS MAY BE CONVERTED TO INFLAMMATION-ASSOCIATED T HELPER 17 CELLS (TH17) WITH TISSUE FIBROSIS PROPERTIES. THE ASSOCIATION BETWEEN FOXP3(+)IL-17(+) T CELLS AND THE ATTENUATION OF RENAL FIBROSIS BY THE HDAC INHIBITOR IS NOT CLEAR. METHODS: THIS STUDY EVALUATED THE ROLES OF THE HDAC INHIBITOR, TREG CELLS AND THEIR DIFFERENTIATION INTO TH17 CELLS, WHICH AGGRAVATE CHRONIC INFLAMMATION AND RENAL FIBROSIS IN A UNILATERAL URETERAL OBSTRUCTION (UUO) MOUSE MODEL. THE STUDY GROUPS INCLUDED CONTROL AND UUO MICE THAT WERE MONITORED FOR 7, 14 OR 21 DAYS. RESULTS: JUXTAGLOMERULAR (JG) HYPERPLASIA, ANGIOTENSIN II TYPE 1 RECEPTOR (AT1R) EXPRESSION AND LYMPHOCYTE INFILTRATION WERE OBSERVED IN RENAL TISSUES AFTER UUO BUT WERE DECREASED AFTER TRICHOSTATIN A (TSA) TREATMENT, A HDAC INHIBITOR. THE NUMBER OF CD4(+)FOXP3(+) T CELLS INCREASED PROGRESSIVELY, ALONG WITH THE NUMBER OF FOXP3(+)INTERLEUKIN (IL)-17(+) T CELLS, AFTER 14 DAYS, AND THEIR NUMBERS THEN PROGRESSIVELY DECREASED WITH INCREASING CD4(+)IL-17(+) T CELL NUMBERS, AS DEMONSTRATED BY DOUBLE IMMUNOHISTOCHEMISTRY. PROGRESSIVE RENAL FIBROSIS WAS ASSOCIATED WITH THE LOSS OF CD4(+)FOXP3(+)IL-17(+) T CELLS IN SPLENIC SINGLE-CELL SUSPENSIONS. FOXP3(+)IL-17(+) T CELLS EXPRESSED TGF-BETA1 BOTH IN VITRO AND IN VIVO, AND TGF-BETA1 EXPRESSION WAS SIGNIFICANTLY KNOCKDOWN BY IL-17 SIRNA IN VITRO. THESE CELLS WERE FOUND TO PLAY A ROLE IN CONVERTING TREGS INTO IL-17- AND TGF-BETA1-PRODUCING CELLS. CONCLUSIONS: TSA TREATMENT DECREASED JG HYPERPLASIA, THE PERCENTAGE OF FOXP3(+)IL-17(+) CELLS AND THE DEGREE OF FIBROSIS, SUGGESTING THAT THERAPEUTIC BENEFITS MAY RESULT FROM EPIGENETIC MODIFICATIONS. 2017 3 137 32 ABERRANT DNA METHYLATION AND EXPRESSION OF SPDEF AND FOXA2 IN AIRWAY EPITHELIUM OF PATIENTS WITH COPD. BACKGROUND: GOBLET CELL METAPLASIA, A COMMON FEATURE OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), IS ASSOCIATED WITH MUCUS HYPERSECRETION WHICH CONTRIBUTES TO THE MORBIDITY AND MORTALITY AMONG PATIENTS. TRANSCRIPTION FACTORS SAM-POINTED DOMAIN-CONTAINING ETS-LIKE FACTOR (SPDEF) AND FORKHEAD BOX PROTEIN A2 (FOXA2) REGULATE GOBLET CELL DIFFERENTIATION. THIS STUDY AIMED TO (1) INVESTIGATE DNA METHYLATION AND EXPRESSION OF SPDEF AND FOXA2 DURING GOBLET CELL DIFFERENTIATION AND (2) COMPARE THIS IN AIRWAY EPITHELIAL CELLS FROM PATIENTS WITH COPD AND CONTROLS DURING MUCOCILIARY DIFFERENTIATION. METHODS: TO ASSESS DNA METHYLATION AND EXPRESSION OF SPDEF AND FOXA2 DURING GOBLET CELL DIFFERENTIATION, PRIMARY AIRWAY EPITHELIAL CELLS, ISOLATED FROM TRACHEA (NON-COPD CONTROLS) AND BRONCHIAL TISSUE (PATIENTS WITH COPD), WERE DIFFERENTIATED BY CULTURE AT THE AIR-LIQUID INTERFACE (ALI) IN THE PRESENCE OF CYTOKINE INTERLEUKIN (IL)-13 TO PROMOTE GOBLET CELL DIFFERENTIATION. RESULTS: WE FOUND THAT SPDEF EXPRESSION WAS INDUCED DURING GOBLET CELL DIFFERENTIATION, WHILE FOXA2 EXPRESSION WAS DECREASED. IMPORTANTLY, CPG NUMBER 8 IN THE SPDEF PROMOTER WAS HYPERMETHYLATED UPON DIFFERENTIATION, WHEREAS DNA METHYLATION OF FOXA2 PROMOTER WAS NOT CHANGED. IN THE ABSENCE OF IL-13, COPD-DERIVED ALI-CULTURED CELLS DISPLAYED HIGHER SPDEF EXPRESSION THAN CONTROL-DERIVED ALI CULTURES, WHEREAS NO DIFFERENCE WAS FOUND FOR FOXA2 EXPRESSION. THIS WAS ACCOMPANIED WITH HYPOMETHYLATION OF CPG NUMBER 6 IN THE SPDEF PROMOTER AND ALSO HYPOMETHYLATION OF CPG NUMBERS 10 AND 11 IN THE FOXA2 PROMOTER. CONCLUSIONS: THESE FINDINGS SUGGEST THAT ABERRANT DNA METHYLATION OF SPDEF AND FOXA2 IS ONE OF THE FACTORS UNDERLYING MUCUS HYPERSECRETION IN COPD, OPENING NEW AVENUES FOR EPIGENETIC-BASED INHIBITION OF MUCUS HYPERSECRETION. 2017 4 362 41 AMBIENT AIR POLLUTION IMPAIRS REGULATORY T-CELL FUNCTION IN ASTHMA. BACKGROUND: ASTHMA IS THE MOST FREQUENT CHRONIC DISEASE IN CHILDREN, AND CHILDREN ARE AT HIGH RISK FOR ADVERSE HEALTH CONSEQUENCES ASSOCIATED WITH AMBIENT AIR POLLUTION (AAP) EXPOSURE. REGULATORY T (TREG) CELLS ARE SUPPRESSORS OF IMMUNE RESPONSES INVOLVED IN ASTHMA PATHOGENESIS. TREG-CELL IMPAIRMENT IS ASSOCIATED WITH INCREASED DNA METHYLATION OF FORKHEAD BOX TRANSCRIPTION FACTOR 3 (FOXP3), A KEY TRANSCRIPTION FACTOR IN TREG-CELL ACTIVITY. BECAUSE AAP EXPOSURE CAN INDUCE EPIGENETIC CHANGES, WE HYPOTHESIZED THAT TREG-CELL FUNCTION WOULD BE IMPAIRED BY AAP, ALLOWING AMPLIFICATION OF AN INFLAMMATORY RESPONSE. OBJECTIVES: TO ASSESS WHETHER EXPOSURE TO AAP LED TO HYPERMETHYLATION OF THE FOXP3 GENE, CAUSING IMPAIRED TREG-CELL SUPPRESSION AND WORSENED ASTHMA SYMPTOM SCORES. METHODS: CHILDREN WITH AND WITHOUT ASTHMA FROM FRESNO, CALIF (HIGH POLLUTION, FRESNO ASTHMA GROUP [FA], N = 71, AND FRESNO NON ASTHMATIC GROUP, N = 30, RESPECTIVELY), AND FROM STANFORD, CALIF (LOW POLLUTION, STANFORD ASTHMA GROUP, N = 40, AND STANFORD NON ASTHMATIC GROUP, N = 40), WERE ENROLLED IN A CROSS-SECTIONAL STUDY. PERIPHERAL BLOOD TREG CELLS WERE USED IN FUNCTIONAL AND EPIGENETIC STUDIES. ASTHMA OUTCOMES WERE ASSESSED BY GLOBAL INITIATIVE IN ASTHMA SCORE. RESULTS: FRESNO ASTHMA GROUP TREG-CELL SUPPRESSION WAS IMPAIRED AND FA TREG-CELL CHEMOTAXIS WERE REDUCED COMPARED WITH OTHER GROUPS (P