Browsing by Subject "Primary Cell Culture"

Now showing 1 - 4 of 4
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    Cellular metabolism constrains innate immune responses in early human ontogeny
    (Nature Research, 2018-11-16) Kan, Bernard; Michalski, Christina; Fu, Helen; Au, Hilda H.T.; Lee, Kelsey; Marchant, Elizabeth A.; Cheng, Maye F.; Anderson-Baucum, Emily; Aharoni-Simon, Michal; Tilley, Peter; Mirmira, Raghavendra G.; Ross, Colin J.; Luciani, Dan S.; Jan, Eric; Lavoie, Pascal M.; Medicine, School of Medicine
    Pathogen immune responses are profoundly attenuated in fetuses and premature infants, yet the mechanisms underlying this developmental immaturity remain unclear. Here we show transcriptomic, metabolic and polysome profiling and find that monocytes isolated from infants born early in gestation display perturbations in PPAR-γ-regulated metabolic pathways, limited glycolytic capacity and reduced ribosomal activity. These metabolic changes are linked to a lack of translation of most cytokines and of MALT1 signalosome genes essential to respond to the neonatal pathogen Candida. In contrast, they have little impact on house-keeping phagocytosis functions. Transcriptome analyses further indicate a role for mTOR and its putative negative regulator DNA Damage Inducible Transcript 4-Like in regulating these metabolic constraints. Our results provide a molecular basis for the broad susceptibility to multiple pathogens in these infants, and suggest that the fetal immune system is metabolically programmed to avoid energetically costly, dispensable and potentially harmful immune responses during ontogeny.
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    A conserved enhancer regulates Il9 expression in multiple lineages
    (Nature Research, 2018-11-15) Koh, Byunghee; Qayum, Amina Abdul; Srivastava, Rajneesh; Fu, Yongyao; Ulrich, Benjamin J.; Janga, Sarath Chandra; Kaplan, Mark H.; Pediatrics, School of Medicine
    Cytokine genes are regulated by multiple regulatory elements that confer tissue-specific and activation-dependent expression. The cis-regulatory elements of the gene encoding IL-9, a cytokine that promotes allergy, autoimmune inflammation and tumor immunity, have not been defined. Here we identify an enhancer (CNS-25) upstream of the Il9 gene that binds most transcription factors (TFs) that promote Il9 gene expression. Deletion of the enhancer in the mouse germline alters transcription factor binding to the remaining Il9 regulatory elements, and results in diminished IL-9 production in multiple cell types including Th9 cells, and attenuates IL-9-dependent immune responses. Moreover, deletion of the homologous enhancer (CNS-18) in primary human Th9 cultures results in significant decrease of IL-9 production. Thus, Il9 CNS-25/IL9 CNS-18 is a critical and conserved regulatory element for IL-9 production.
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    Neutralizing negative epigenetic regulation by HDAC5 enhances human haematopoietic stem cell homing and engraftment
    (Nature Publishing Group, 2018-07-16) Huang, Xinxin; Guo, Bin; Liu, Sheng; Wan, Jun; Broxmeyer, Hal E.; Microbiology and Immunology, School of Medicine
    Enhancement of hematopoietic stem cell (HSC) homing and engraftment is clinically critical, especially for cord blood (CB) hematopoietic cell transplantation. Here we report that specific HDAC5 inhibition highly upregulates CXCR4 surface expression in human CB HSCs and progenitor cells (HPCs). This results in enhanced SDF-1/CXCR4-mediated chemotaxis and increased homing to the bone marrow environment, with elevated SCID-repopulating cell (SRC) frequency and enhanced long-term and secondary engraftment in NSG mice. HDAC5 inhibition increases acetylated p65 levels in the nucleus, which is important for CXCR4 transcription. Inhibition of nuclear factor-κB (NF-κB) signaling suppresses HDAC5-mediated CXCR4 upregulation, enhanced HSC homing, and engraftment. Furthermore, activation of the NF-κB signaling pathway via TNFα also results in significantly increased CXCR4 surface expression, enhanced HSC homing, and engraftment. These results demonstrate a previously unknown negative epigenetic regulation of HSC homing and engraftment by HDAC5, and allow for a new and simple translational strategy to enhance HSC transplantation.
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    Uhrf1 regulates active transcriptional marks at bivalent domains in pluripotent stem cells through Setd1a
    (Nature Publishing Group, 2018-07-03) Kim, Kun-Yong; Tanaka, Yoshiaki; Su, Juan; Cakir, Bilal; Xiang, Yangfei; Patterson, Benjamin; Ding, Junjun; Jung, Yong-Wook; Kim, Ji-Hyun; Hysolli, Eriona; Lee, Haelim; Dajani, Rana; Kim, Jonghwan; Zhong, Mei; Lee, Jeong-Heon; Skalnik, David; Lim, Jeong Mook; Sullivan, Gareth J.; Wang, Jianlong; Park, In-Hyun; Biology, School of Science
    Embryonic stem cells (ESCs) maintain pluripotency through unique epigenetic states. When ESCs commit to a specific lineage, epigenetic changes in histones and DNA accompany the transition to specialized cell types. Investigating how epigenetic regulation controls lineage specification is critical in order to generate the required cell types for clinical applications. Uhrf1 is a widely known hemi-methylated DNA-binding protein, playing a role in DNA methylation through the recruitment of Dnmt1 and in heterochromatin formation alongside G9a, Trim28, and HDACs. Although Uhrf1 is not essential in ESC self-renewal, it remains elusive how Uhrf1 regulates cell specification. Here we report that Uhrf1 forms a complex with the active trithorax group, the Setd1a/COMPASS complex, to maintain bivalent histone marks, particularly those associated with neuroectoderm and mesoderm specification. Overall, our data demonstrate that Uhrf1 safeguards proper differentiation via bivalent histone modifications.