617 research outputs found

    Galectin-3 Modulates Th17 Responses by Regulating Dendritic Cell Cytokines

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    Galectin-3 is a β-galactoside–binding animal lectin with diverse functions, including regulation of T helper (Th) 1 and Th2 responses. Current data indicate that galectin-3 expressed in dendritic cells (DCs) may be contributory. Th17 cells have emerged as critical inducers of tissue inflammation in autoimmune disease and important mediators of host defense against fungal pathogens, although little is known about galectin-3 involvement in Th17 development. We investigated the role of galectin-3 in the induction of Th17 immunity in galectin-3–deficient (gal3−/−) and gal3+/+ mouse bone marrow–derived DCs. We demonstrate that intracellular galectin-3 negatively regulates Th17 polarization in response to the dectin-1 agonist curdlan (a β-glucan present on the cell wall of fungal species) and lipopolysaccharide, agents that prime DCs for Th17 differentiation. On activation of dectin-1, gal3−/− DCs secreted higher levels of the Th17-axis cytokine IL-23 compared with gal3+/+ DCs and contained higher levels of activated c-Rel, an NF-κB subunit that promotes IL-23 expression. Levels of active Raf-1, a kinase that participates in downstream inhibition of c-Rel binding to the IL23A promoter, were impaired in gal3−/− DCs. Modulation of Th17 by galectin-3 in DCs also occurred in vivo because adoptive transfer of gal3−/− DCs exposed to Candida albicans conferred higher Th17 responses and protection against fungal infection. We conclude that galectin-3 suppresses Th17 responses by regulating DC cytokine production

    DETERMINATION OF MICROSCOPIC PARTICLE COUNT OF CRYPTOSPORIDIUM AND GIARDIA CYSTS USING MEMBRANE FILTERS

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    Wang, LK, Wang, MHS, and Wu, BC (2022). Determination of microscopic particle count of Cryptosporidium and Giardia cysts using membrane filters. In: “Environmental Science, Technology, Engineering and Mathematics (STEM)”, Wang, LK, Wang, MHS and Pankivskyi, YI (eds.), 2022(12C), STEM-VOL2022-NUM12C-DEC2022. 21 pages. December 2022, Lenox Institute Press, Massachusetts, USA. https://doi.org/10.17613/97wt-bb20 ..... ABSTRACT: Cryptosporidium is an intestinal coccidian protozoan parasite about 3.5 micrometers (um) in diameter. Giardia is the genus name for a group of single-celled, flagellated, pathogenic protozoans about 8 micrometer (um) in diameter. Both Cryptosporidium and Giardia are normally found in a variety of vertebrates, such as mammals, birds, and reptiles, and are responsible for waterborne disease outbreaks. At present, no practical means of rapid detection for Cryptosporidium and Giardia cysts can be employed. The APHA/AWWA/WEF Standard Methods' microscopic count or particle count of plankton is currently used for monitoring a water treatment plant's efficiency for removal of Cryptosporidium and Giardia cysts. The authors of the Lenox Institute of Water Technology (LIWT) introduce a simple and more accurate microscopic method as a substitute to verify removal of cyst-size (Cryptosporidium and Giardia cysts) contaminants by a water treatment plant. It should be noted, however, the rapid particle count method has been developed by LIWT using the 8-um member filter which was certified by Millipore Corporation for retaining and counting the 8-um Giardia cysts. A 3.54-um member filter should be used for retaining and counting both the Cryptosporidium and Giardia cysts. The difference between the two counts will be the number of Cryptosporidium

    DETERMINATION OF TOTAL MERCAPTANS IN WATER AND WASTEWATER BY SPECTROPHOTOMETRY

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    Wang, MHS, Wang, LK, and Wu, BC (2022). Determination of total mercaptans in water and wastewater by spectrophotometry. In: "Environmental Science, Technology, Engineering, and Mathematics (STEM)", Wang, LK, Wang, MHS, and Pankivskyi, YI (editors). Volume 2022, Number 4C, April 2022; pp.26. Lenox Institute Press, MA, USA. https://doi.org/10.17613/krd0-cs31 . ....ABSTRACT: This publication initially introduces the environmental engineering significance of an odor-causing chemical group, known as mercaptans, and subsequently introduces a spectrophotometric method for determination of total mercaptans in water and wastewater. The mercaptans are very useful additives to colorless natural gases and toxic pesticides giving them warning signals to humans. However, their residuals are the undesirable environmental pollutants causing odor problems in air and taste problem in drinking water. There has been no effective quantitative method for determination of mercaptan concentrations in water and wastewater. The authors introduce this simple spectrophotometric method and invite researchers for further statistical as well as analytical research. It is the authors' hope that one day a Standard Method for the total mercaptans determination can be finalized. Lead mercaptide has been used for preparation of mercaptan standard solution and preparation of calibration curves. After a water sample containing mercaptans reacts with an absorbing solution and a color developing reagent, its filtrate's absorbance is measured in 5 cm cells at 500 nm using a spectrophotometer

    DETERMINATION OF SOLUBLE HUMIC SUBSTANCES (HUMIC ACID, FULVIC ACID & SALTS) IN WATER BY UV-VISIBLE SPECTROPHOTOMETRY

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    Wang, MHS, Wang, LK, Wu, BC and Hu, GY (2022). Determination of humic substances (humic acid, fulvic acid & salts) in water by UV-visible spectrophotometry. In: "Environmental Science, Technology, Engineering, and Mathematics (STEM)", Wang, LK, Wang, MHS, and Pankivskyi, YI (editors). Volume 2022, Number 4B, April 2022; pp.33. Lenox Institute Press, MA, USA. 10.17613/g0e5-wr96 ..........ABSTRACT: An analytical procedure has been developed for quantitative determination of soluble humic substances which are common agricultural and gardening products. The residual of soluble humic substances in surface water become the undesirable trihalomethane (THM) precursors to people and chronic toxic substances to aquatic plants and animals. Removal and analysis of soluble humic substances are important tasks of environmental researchers. The principle of humic substances is similar to that of tannin and lignin analysis except that the two analytical methods use different analytical instruments. The principle is that soluble humic substances, such as humic acid, fulvic acid and their salts, reduce the tungstophosphoric and molybdophosphoric acids to produce a grayish color up to at least 20 mg/L at UV wavelength 265-400 nm. The grayish color substance can be quantitatively measured with a UV-Visible Spectrophotometer. This publication is one of the authors' memoirs

    Therapeutic targeting of ependymoma as informed by oncogenic enhancer profiling

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    Genomic sequencing has driven precision-based oncology therapy; however, the genetic drivers of many malignancies remain unknown or non-targetable, so alternative approaches to the identification of therapeutic leads are necessary. Ependymomas are chemotherapy-resistant brain tumours, which, despite genomic sequencing, lack effective molecular targets. Intracranial ependymomas are segregated on the basis of anatomical location (supratentorial region or posterior fossa) and further divided into distinct molecular subgroups that reflect differences in the age of onset, gender predominance and response to therapy1,2,3. The most common and aggressive subgroup, posterior fossa ependymoma group A (PF-EPN-A), occurs in young children and appears to lack recurrent somatic mutations2. Conversely, posterior fossa ependymoma group B (PF-EPN-B) tumours display frequent large-scale copy number gains and losses but have favourable clinical outcomes1,3. More than 70% of supratentorial ependymomas are defined by highly recurrent gene fusions in the NF-κB subunit gene RELA (ST-EPN-RELA), and a smaller number involve fusion of the gene encoding the transcriptional activator YAP1 (ST-EPN-YAP1)1,3,4. Subependymomas, a distinct histologic variant, can also be found within the supratetorial and posterior fossa compartments, and account for the majority of tumours in the molecular subgroups ST-EPN-SE and PF-EPN-SE. Here we describe mapping of active chromatin landscapes in 42 primary ependymomas in two non-overlapping primary ependymoma cohorts, with the goal of identifying essential super-enhancer-associated genes on which tumour cells depend. Enhancer regions revealed putative oncogenes, molecular targets and pathways; inhibition of these targets with small molecule inhibitors or short hairpin RNA diminished the proliferation of patient-derived neurospheres and increased survival in mouse models of ependymomas. Through profiling of transcriptional enhancers, our study provides a framework for target and drug discovery in other cancers that lack known genetic drivers and are therefore difficult to treat.This work was supported by an Alex's Lemonade Stand Young Investigator Award (S.C.M.), The CIHR Banting Fellowship (S.C.M.), The Cancer Prevention Research Institute of Texas (S.C.M., RR170023), Sibylle Assmus Award for Neurooncology (K.W.P.), the DKFZ-MOST (Ministry of Science, Technology & Space, Israel) program in cancer research (H.W.), James S. McDonnell Foundation (J.N.R.) and NIH grants: CA154130 (J.N.R.), R01 CA169117 (J.N.R.), R01 CA171652 (J.N.R.), R01 NS087913 (J.N.R.) and R01 NS089272 (J.N.R.). R.C.G. is supported by NIH grants T32GM00725 and F30CA217065. M.D.T. is supported by The Garron Family Chair in Childhood Cancer Research, and grants from the Pediatric Brain Tumour Foundation, Grand Challenge Award from CureSearch for Children’s Cancer, the National Institutes of Health (R01CA148699, R01CA159859), The Terry Fox Research Institute and Brainchild. M.D.T. is also supported by a Stand Up To Cancer St. Baldrick’s Pediatric Dream Team Translational Research Grant (SU2C-AACR-DT1113)

    Fully automatic landmarking of 2D photographs identifies novel genetic loci influencing facial features

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    We report a genome-wide association study for facial features in > 6,000 Latin Americans. We placed 106 landmarks on 2D frontal photographs using the cloud service platform Face++. After Procrustes superposition, genome-wide association testing was performed for 301 inter-landmark distances. We detected nominally significant association (P-value < 5×10− 8) for 42 genome regions. Of these, 9 regions have been previously reported in GWAS of facial features. In follow-up analyses, we replicated 26 of the 33 novel regions (in East Asians or Europeans). The replicated regions include 1q32.3, 3q21.1, 8p11.21, 10p11.1, and 22q12.1, all comprising strong candidate genes involved in craniofacial development. Furthermore, the 1q32.3 region shows evidence of introgression from archaic humans. These results provide novel biological insights into facial variation and establish that automatic landmarking of standard 2D photographs is a simple and informative approach for the genetic analysis of facial variation, suitable for the rapid analysis of large population samples.- Introduction - Results And Discussion -- Study sample and phenotyping -- Trait/covariate correlation and heritability -- Overview of GWAS results and integration with the literature -- Follow-up of genomic regions newly associated with facial features: Replication in two human cohorts -- Follow-up of genomic regions newly associated with facial features: effects in the mouse -- Genome annotations at associated loci - Conclusion - Methods -- Study subjects -- Genotype data -- Phenotyping -- Statistical genetic analysis -- Interaction of EDAR with other genes -- Expression analysis for significant SNPs -- Detection of archaic introgression near ATF3 and association with facial features -- Annotation of SNPs in FUMA -- Shape GWAS in outbred mic

    Characterization of Neutralizing Profiles in HIV-1 Infected Patients from whom the HJ16, HGN194 and HK20 mAbs were Obtained

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    Several new human monoclonal antibodies (mAbs) with a neutralizing potential across different subtypes have recently been described. Three mAbs, HJ16, HGN194 and HK20, were obtained from patients within the HIV-1 cohort of the Institute of Tropical Medicine (ITM). Our aim was to generate immunization antibodies equivalent to those seen in plasma. Here, we describe the selection and characterization of patient plasma and their mAbs, using a range of neutralization assays, including several peripheral blood mononuclear cell (PBMC) based assays and replicating primary viruses as well as cell line based assays and pseudoviruses (PV). The principal criterion for selection of patient plasma was the activity in an ‘extended incubation phase’ PBMC assay. Neutralizing Abs, derived from their memory B cells, were then selected by ELISA with envelope proteins as solid phase. MAbs were subsequently tested in a high-throughput HOS-PV assay to assess functional neutralization. The present study indicates that the strong profiles in the patients' plasma were not solely due to antibodies represented by the newly isolated mAbs. Although results from the various assays were divergent, they by and large indicate that neutralizing Abs to other epitopes of the HIV-1 envelope are present in the plasma and synergy between Abs may be important. Thus, the spectrum of the obtained mAbs does not cover the range of cross-reactivity seen in plasma in these carefully selected patients irrespective of which neutralization assay is used. Nevertheless, these mAbs are relevant for immunogen discovery because they bind to the recombinant glycoproteins to which the immune response needs to be targeted in vivo. Our observations illustrate the remaining challenges required for successful immunogen design and development

    A Functional Variant in MicroRNA-146a Promoter Modulates Its Expression and Confers Disease Risk for Systemic Lupus Erythematosus

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    Systemic lupus erythematosus (SLE) is a complex autoimmune disease with a strong genetic predisposition, characterized by an upregulated type I interferon pathway. MicroRNAs are important regulators of immune homeostasis, and aberrant microRNA expression has been demonstrated in patients with autoimmune diseases. We recently identified miR-146a as a negative regulator of the interferon pathway and linked the abnormal activation of this pathway to the underexpression of miR-146a in SLE patients. To explore why the expression of miR-146a is reduced in SLE patients, we conducted short parallel sequencing of potentially regulatory regions of miR-146a and identified a novel genetic variant (rs57095329) in the promoter region exhibiting evidence for association with SLE that was replicated independently in 7,182 Asians (Pmeta = 2.74×10−8, odds ratio = 1.29 [1.18–1.40]). The risk-associated G allele was linked to reduced expression of miR-146a in the peripheral blood leukocytes of the controls. Combined functional assays showed that the risk-associated G allele reduced the protein-binding affinity and activity of the promoter compared with those of the promoter containing the protective A allele. Transcription factor Ets-1, encoded by the lupus-susceptibility gene ETS1, identified in recent genome-wide association studies, binds near this variant. The manipulation of Ets-1 levels strongly affected miR-146a promoter activity in vitro; and the knockdown of Ets-1, mimicking its reduced expression in SLE, directly impaired the induction of miR-146a. We also observed additive effects of the risk alleles of miR-146a and ETS1. Our data identified and confirmed an association between a functional promoter variant of miR-146a and SLE. This risk allele had decreased binding to transcription factor Ets-1, contributing to reduced levels of miR-146a in SLE patients

    Association of genetic variants in complement factor H and factor H-related genes with systemic lupus erythematosus susceptibility

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    Systemic lupus erythematosus (SLE), a complex polygenic autoimmune disease, is associated with increased complement activation. Variants of genes encoding complement regulator factor H (CFH) and five CFH-related proteins (CFHR1-CFHR5) within the chromosome 1q32 locus linked to SLE, have been associated with multiple human diseases and may contribute to dysregulated complement activation predisposing to SLE. We assessed 60 SNPs covering the CFH-CFHRs region for association with SLE in 15,864 case-control subjects derived from four ethnic groups. Significant allelic associations with SLE were detected in European Americans (EA) and African Americans (AA), which could be attributed to an intronic CFH SNP (rs6677604, in intron 11, Pmeta = 6.6×10-8, OR = 1.18) and an intergenic SNP between CFHR1 and CFHR4 (rs16840639, Pmeta = 2.9×10-7, OR = 1.17) rather than to previously identified disease-associated CFH exonic SNPs, including I62V, Y402H, A474A, and D936E. In addition, allelic association of rs6677604 with SLE was subsequently confirmed in Asians (AS). Haplotype analysis revealed that the underlying causal variant, tagged by rs6677604 and rs16840639, was localized to a ~146 kb block extending from intron 9 of CFH to downstream of CFHR1. Within this block, the deletion of CFHR3 and CFHR1 (CFHR3-1Δ), a likely causal variant measured using multiplex ligation-dependent probe amplification, was tagged by rs6677604 in EA and AS and rs16840639 in AA, respectively. Deduced from genotypic associations of tag SNPs in EA, AA, and AS, homozygous deletion of CFHR3-1Δ (Pmeta = 3.2×10-7, OR = 1.47) conferred a higher risk of SLE than heterozygous deletion (Pmeta = 3.5×10-4, OR = 1.14). These results suggested that the CFHR3-1Δ deletion within the SLE-associated block, but not the previously described exonic SNPs of CFH, might contribute to the development of SLE in EA, AA, and AS, providing new insights into the role of complement regulators in the pathogenesis of SLE
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