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1.
Immunohorizons ; 4(5): 282-291, 2020 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-32439753

RESUMO

Generation of allelic gene reporter mice has provided a powerful tool to study gene function in vivo. In conjunction with imaging technologies, reporter mouse models facilitate studies of cell lineage tracing, live cell imaging, and gene expression in the context of diseases. Although there are several advantages to using reporter mice, caution is important to ensure the fidelity of the reporter protein representing the gene of interest. In this study, we compared the efficiency of two Il9 reporter strains Il9citrine and Il9GFP in representing IL-9-producing CD4+ TH9 cells. Although both alleles show high specificity in IL-9-expressing populations, we observed that the Il9GFP allele visualized a much larger proportion of the IL-9-producing cells in culture than the Il9citrine reporter allele. In defining the mechanistic basis for these differences, chromatin immunoprecipitation and chromatin accessibility assay showed that the Il9citrine allele was transcriptionally less active in TH9 cells compared with the wild-type allele. The Il9citrine allele also only captured a fraction of IL-9-expressing bone marrow-derived mast cells. In contrast, the Il9 citrine reporter detected Il9 expression in type 2 innate lymphoid cells at a greater percentage than could be identified by IL-9 intracellular cytokine staining. Taken together, our findings demonstrate that the accuracy of IL-9 reporter mouse models may vary with the cell type being examined. These studies demonstrate the importance of choosing appropriate reporter mouse models that are optimal for detecting the cell type of interest as well as the accuracy of conclusions.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32179158

RESUMO

BACKGROUND: Bcl6 is required for the development of T follicular helper cells and T follicular regulatory (Tfr) cells that regulate germinal center responses. Bcl6 also affects the function of regulatory T (Treg) cells. OBJECTIVE: The goal of this study was to define the functions of Bcl6 in Treg cells, including Tfr cells, in the context of allergic airway inflammation. METHODS: We used a model of house dust mite sensitization to challenge wild-type, Bcl6fl/fl Foxp3-Cre, and Prdm1 (Blimp1)fl/fl Foxp3-Cre mice to study the reciprocal roles of Bcl6 and Blimp1 in allergic airway inflammation. RESULTS: In the house dust mite model, Tfr cells repress the production of IgE and Bcl6+ Treg cells suppress the generation of type 2 cytokine-producing cells in the lungs. In mice with Bcl6-deficient Treg cells, twice as many ST2+ (IL-33R+) Treg cells develop as are observed in wild-type mice. ST2+ Treg cells in the context of allergic airway inflammation are Blimp1 dependent, express type 2 cytokines, and share features of visceral adipose tissue Treg cells. Bcl6-deficient Treg cells are more susceptible, and Blimp1-deficient Treg cells are resistant, to acquiring the ST2+ Treg-cell phenotype in vitro and in vivo in response to IL-33. Bcl6-deficient ST2+ Treg cells, but not Bcl6-deficient ST2+ conventional T cells, strongly promote allergic airway inflammation when transferred into recipient mice. Lastly, ST2 is required for the exacerbated allergic airway inflammation in Bcl6fl/fl Foxp3-Cre mice. CONCLUSIONS: During allergic airway inflammation, Bcl6 and Blimp1 play dual roles in regulating Tfr-cell activity in the germinal center and in the development of ST2+ Treg cells that promote type 2 cytokine responses.

3.
J Immunol ; 203(7): 1989-1998, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31451674

RESUMO

The basic leucine zipper (bZIP) transcription factor BATF is expressed in multiple Th subsets and cooperates with other factors to regulate gene transcription. BATF activates lineage-specific cytokines in Th subsets, activating IL-9 in Th9 cells and IL-17 in Th17 cells, but not IL-9 or IL-17 in the reciprocal subset. The mechanism for this restricted activity is unclear. In this report, we define BATF binding partners that contribute to Th subset-specific functions. Although BATF and IRF4 are expressed in greater amounts in Th9 than Th17, increased expression of both factors is not sufficient to induce IL-9 in Th17 cells. BATF also requires heterodimer formation with Jun family members to bind DNA and induce gene expression. Using primary mouse T cell culture, we observed that JunB and c-Jun, but not JunD, promote IL-9 production in Th9 cells. Ectopic expression of BATF with either JunB or c-Jun generates modest, but significant, increases in IL-9 production in Th17 cells, suggesting that the low expression of Jun family members is one factor limiting the ability of BATF to induce IL-9 in Th17 cells. We further identified that Bach2 positively regulates IL-9 production by directly binding to the Il9 gene and by increasing transcription factor expression in Th9 cells. Strikingly, cotransduction of Bach2 and BATF significantly induces IL-9 production in both Th9 and Th17 cells. Taken together, our results reveal that JunB, c-Jun, and Bach2 cooperate with BATF to contribute to the specificity of BATF-dependent cytokine induction in Th subsets.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/imunologia , Regulação da Expressão Gênica/imunologia , Células Th17/imunologia , Animais , Fatores de Transcrição de Zíper de Leucina Básica/genética , Humanos , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/imunologia , Interleucina-9/genética , Interleucina-9/imunologia , Camundongos , Camundongos Transgênicos , Células Th17/citologia , Fatores de Transcrição/genética , Fatores de Transcrição/imunologia
4.
J Immunol ; 203(5): 1111-1121, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31350354

RESUMO

IL-9 is an important mediator of allergic disease that is critical for mast cell-driven diseases. IL-9 is produced by many cell types, including T cells, basophils, and mast cells. Yet, how IL-9 is regulated in mast cells or basophils is not well characterized. In this report, we tested the effects of deficiency of a mouse Il9 gene regulatory element (Il9 CNS-25) in these cells in vivo and in vitro. In mast cells stimulated with IL-3 and IL-33, the Il9 CNS-25 enhancer is a potent regulator of mast cell Il9 gene transcription and epigenetic modification at the Il9 locus. Our data show preferential binding of STAT5 and GATA1 to CNS-25 over the Il9 promoter in mast cells and that T cells and mast cells have differing requirements for the induction of IL-9 production. Il9 CNS-25 is required for IL-9 production from T cells, basophils, and mast cells in a food allergy model, and deficiency in IL-9 expression results in decreased mast cell expansion. In a Nippostrongylus brasiliensis infection model, we observed a similar decrease in mast cell accumulation. Although decreased mast cells correlated with higher parasite egg burden and delayed clearance in vivo, T cell deficiency in IL-9 also likely contributes to the phenotype. Thus, our data demonstrate IL-9 production in mast cells and basophils in vivo requires Il9 CNS-25, and that Il9 CNS-25-dependent IL-9 production is required for mast cell expansion during allergic intestinal inflammation.


Assuntos
Basófilos/imunologia , Genes Reguladores , Interleucina-9/genética , Mastócitos/imunologia , Animais , Feminino , Hipersensibilidade Alimentar/imunologia , Helmintíase/imunologia , Interleucina-9/biossíntese , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL
5.
ACS Chem Biol ; 13(1): 45-52, 2018 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-29193961

RESUMO

The standard-of-care therapeutics for the treatment of ocular neovascular diseases like wet age-related macular degeneration (AMD) are biologics targeting vascular endothelial growth factor signaling. There are currently no FDA approved small molecules for treating these blinding eye diseases. Therefore, therapeutic agents with novel mechanisms are critical to complement or combine with existing approaches. Here, we identified soluble epoxide hydrolase (sEH), a key enzyme for epoxy fatty acid metabolism, as a target of an antiangiogenic homoisoflavonoid, SH-11037. SH-11037 inhibits sEH in vitro and in vivo and docks to the substrate binding cleft in the sEH hydrolase domain. sEH levels and activity are up-regulated in the eyes of a choroidal neovascularization (CNV) mouse model. sEH is overexpressed in human wet AMD eyes, suggesting that sEH is relevant to neovascularization. Known sEH inhibitors delivered intraocularly suppressed CNV. Thus, by dissecting a bioactive compound's mechanism, we identified a new chemotype for sEH inhibition and characterized sEH as a target for blocking the CNV that underlies wet AMD.


Assuntos
Cromonas/farmacologia , Epóxido Hidrolases/antagonistas & inibidores , Epóxido Hidrolases/metabolismo , Terapia de Alvo Molecular/métodos , Fenilalanina/análogos & derivados , Degeneração Macular Exsudativa/metabolismo , Inibidores da Angiogênese/farmacologia , Animais , Sítios de Ligação , Neovascularização de Coroide/tratamento farmacológico , Neovascularização de Coroide/metabolismo , Cromonas/química , Modelos Animais de Doenças , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Epóxido Hidrolases/química , Ácidos Graxos Insaturados/metabolismo , Humanos , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular , Fenilalanina/química , Fenilalanina/farmacologia , Domínios Proteicos , Proteômica/métodos , Degeneração Macular Exsudativa/patologia
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