RNA-based biomarkers have been successfully detected at field sites undergoing bioremediation, but the detection of expressed enzymes is a more direct way to prove activity for a particular biocatalytic process of interest since they provide evidence of potential activity rather than simply confirming presence and abundance of genes in a given population by measurement of DNA copies using qPCR. Here we successfully applied shotgun proteomics to field samples from a trichloroethene (TCE)-contaminated industrial site in southern Ontario, Canada that had been bio-augmented with the commercially available KB-1 microbial culture. The KB-1 culture contains multiple strains of () as well as an organohalide respiring species.
View Article and Find Full Text PDFUsing mRNA transcript levels for key functional enzymes as proxies for the organohalide respiration (OHR) rate, is a promising approach for monitoring bioremediation populations in situ at chlorinated solvent-contaminated field sites. However, to date, no correlations have been empirically derived for chlorinated solvent respiring, (DMC) containing, bioaugmentation cultures. In the current study, genome-wide transcriptome and proteome data were first used to confirm the most highly expressed OHR-related enzymes in the bioaugmentation culture, KB-1, including several reductive dehalogenases (RDases) and a Ni-Fe hydrogenase, Hup.
View Article and Find Full Text PDFThe interpretation of high-throughput gene expression data for non-model microorganisms remains obscured because of the high fraction of hypothetical genes and the limited number of methods for the robust inference of gene networks. Therefore, to elucidate gene-gene and gene-condition linkages in the bioremediation-important genus Dehalococcoides, we applied a Bayesian inference strategy called Reverse Engineering/Forward Simulation (REFS™) on transcriptomic data collected from two organohalide-respiring communities containing different Dehalococcoides mccartyi strains: the Cornell University mixed community D2 and the commercially available KB-1® bioaugmentation culture. In total, 49 and 24 microarray datasets were included in the REFS™ analysis to generate an ensemble of 1,000 networks for the Dehalococcoides population in the Cornell D2 and KB-1® culture, respectively.
View Article and Find Full Text PDFTo better understand the quantitative relationships between messenger RNA (mRNA) and protein biomarkers relevant to bioremediation, we quantified and compared respiration-associated gene products in an anaerobic syntrophic community. Respiration biomarkers for Dehalococcoides, an organohalide reducer, and Methanospirillum, a hydrogenotrophic methanogen, were quantified via qRT-PCR for mRNA and multiple reaction monitoring (MRM) of proteotypic peptides for protein. mRNA transcripts of the Dehalococcoides reductive dehalogenases PceA, TceA, and DMC1545, and hydrogenase HupL, as well as the Methanospirillum oxidoreductases MvrD and FrcA were shown to be similarly regulated with respect to their temporal responses to substrate addition.
View Article and Find Full Text PDFA cDNA-microarray was designed and used to monitor the transcriptomic profile of Dehalococcoides mccartyi strain 195 (in a mixed community) respiring various chlorinated organics, including chloroethenes and 2,3-dichlorophenol. The cultures were continuously fed in order to establish steady-state respiration rates and substrate levels. The organization of array data into a clustered heat map revealed two major experimental partitions.
View Article and Find Full Text PDFDehalococcoides mccartyi detectability in the field is a fundamental tool to assess the efficiency of natural attenuation or engineered bioremediation in chlorinated solvent-contaminated sites. This study reports on the direct comparison of quantitative data obtained by Real Time PCR (qPCR) and CAtalyzed Reporter Deposition-Fluorescence In situ Hybridization (CARD-FISH) over a wide range of Dehalococcoides concentrations (10-10(8) cells mL(-1)) both in three independent 10-fold serial dilutions of a laboratory dechlorinating enrichment and in 49 groundwater samples from 6 different contaminated sites. Dehalococcoides enumeration by CARD-FISH yielded a linear curve in the analyzed concentration range which was consistent with the expected concentrations and showed good reproducibility in triplicate assays.
View Article and Find Full Text PDFMolecular biomarkers hold promise for inferring rates of key metabolic activities in complex microbial systems. However, few studies have assessed biomarker levels for simultaneously occurring (and potentially competing) respirations. In this study, methanogenesis biomarkers for Methanospirillum hungatei were developed, tested, and compared to Dehalococcoides mccartyi biomarkers in a well-characterized mixed culture.
View Article and Find Full Text PDFMolecular biomarkers could provide critical insight into myriad in situ microbial activities. In this study we explore correlations of both mRNA and protein biomarkers with chloroethene respiration rate in Dehalococcoides. In a series of continuously fed dechlorinating mixed-culture microcosm experiments (n = 26), we varied respiratory substrates, substrate ratios and feeding rates.
View Article and Find Full Text PDFThere are a number of proteins whose active forms are non-covalent multichain complexes. Therapeutic intervention involving such complexes has been proposed through the use of muteins to form heterostructures. These resulting structures would either not be recognized by receptors or would be inactive competitive inhibitors to wild-type (wt) proteins.
View Article and Find Full Text PDFMonoclonal antibody (mAb) therapy was first established upon the approval of a mouse antibody for treatment of human acute organ rejection. However, the high incidence of immune response against the mouse mAb restricted therapeutic utility. Development of chimeric, "humanized" and human mAbs broadened therapeutic application to immune-mediated diseases requiring long-term treatment.
View Article and Find Full Text PDFInterleukin (IL)-12 and IL-23 are heterodimeric proinflammatory cytokines that share a common p40 subunit, paired with p35 and p19 subunits, respectively. They represent an attractive class of therapeutic targets for the treatment of psoriasis and other immune-mediated diseases. Ustekinumab is a fully human monoclonal antibody (mAb) that binds specifically to IL-12/IL-23p40 and neutralizes human IL-12 and IL-23 bioactivity.
View Article and Find Full Text PDFErythropoietin therapy is used to treat severe anemia in renal failure and chemotherapy patients. One of these therapies based on recombinant human erythropoietin is marketed under the trade name of EPREX and utilizes epoetinum alfa as the active pharmaceutical ingredient. The effect of oxidation of methionine-54 on the structure and stability of the erythropoietin molecule has not been directly tested.
View Article and Find Full Text PDFDuring the period of 1998 to 2002, there was an increase in the incidence of antibody-positive pure red cell aplasia (PRCA) in patients receiving subcutaneous administration of EPREX (epoetinum alfa). As part of the investigation of this event, the aqueous formulation containing polysorbate 80, introduced in 1998, facilitated the leaching of small-molecule, aromatic compounds from the uncoated rubber syringe stoppers. The leachables were identified using Liquid Chromatography-Mass Spectroscopy, Electrospray Ionisation-MS/MS, Dithiothreitol reduction, and Hydrogen/Deuterium exchange.
View Article and Find Full Text PDFIn the biotechnology area, the issue of comparability with an innovator product is complex. Ideally, a side-by-side comparison of physical properties would be part of the demonstration of comparability. However, biogeneric companies do not have access to the bulk drug substance from the innovator company for biophysical comparison, and isolation of protein from marketed product cannot be guaranteed to produce material that is identical to the bulk drug substance from which it was prepared.
View Article and Find Full Text PDFBackground And Purpose: Recombinant human erythropoietin (rhEPO; Epoetin-alpha; PROCRITtrade mark) has been shown to exert neuroprotective and restorative effects in a variety of CNS injury models. However, limited information is available regarding the dose levels required for these beneficial effects or the neuronal responses that may underlie them. Here we have investigated the dose-response to rhEPO and compared the effects of rhEPO with those of carbamylated rhEPO (CEPO) in a model of cerebral stroke in rats.
View Article and Find Full Text PDFCytokines in plasmid form can act as potent adjuvants when co-administered with DNA vaccines, resulting in an enhanced immune response to the DNA-encoded antigen. This is true of interleukin-18 (IL-18), which has been shown to serve as an adjuvant in conjunction with certain DNA vaccines. To determine if the properties of IL-18 could be optimized for use as a DNA vaccine adjuvant, a model of IL-18/IL-18R binding was developed to identify variants of human IL-18 that were predicted to improve receptor interactions and potentially bioactivity.
View Article and Find Full Text PDFThe incidence of pure red cell aplasia (PRCA) in patients with chronic kidney disease associated with the subcutaneous (s.c.) administration of epoetin alfa (EPREX) began to increase in 1998.
View Article and Find Full Text PDFHuman monocyte chemoattractant protein 1 (MCP-1, CCL2) is a 8.6-kDa protein that has been implicated in a number of diseases including atherosclerosis, rheumatoid arthritis, chronic obstructive pulmonary disease and cancer. As part of a program to identify antibodies against MCP-1, we synthesized site-specific, biotinylated human MCP-1 analogs to be used for panning of an antibody phage display library.
View Article and Find Full Text PDFPurpose: The cause of antibody positive pure red cell aplasia associated with the subcutaneous administration of EPREX to patients with chronic kidney failure has been determined to be due to the leaching of weakly adjuvant compounds from the uncoated rubber stoppers that were formerly used in prefilled syringes. Other researchers have suggested that polysorbate 80 micelles containing erythropoietin may be a causative factor. The purpose of this work was to repeat previously published studies in a more controlled manner and to define the precise nature of the interactions between polysorbate 80 and erythropoietin.
View Article and Find Full Text PDFNovel analogs of human monocyte chemoattractant protein 1 (MCP-1) were designed, synthesized and characterized to be used as tools to generate monoclonal antibodies as potential human therapeutics. MCP-1 and three analogs were synthesized by step-wise Fmoc solid phase synthesis. After oxidation to form the two-disulfide bonds, affinity chromatography using an immobilized mouse anti-human MCP-1 monoclonal antibody (mAb) was utilized for a simple and highly effective purification procedure for the proteins.
View Article and Find Full Text PDFMonoclonal antibodies have been firmly established as human therapeutics. Their high affinity and specificity for target antigens minimize adverse reactions and their molecular size results in extended circulation times relative to small molecule pharmaceuticals. The ability to customize the pharmacokinetics in a rational manner can enhance the potential for these and other classes of biologicals.
View Article and Find Full Text PDFInterleukin-8 (IL-8) plays a central role in neutrophil chemotaxis and exerts a wide range of effects on various cells, ranging from tumor angiogenesis to impairment of neuronal signaling. Two main forms of IL-8 exist, one containing 77 amino acids (Ala-IL-8(77)) and a second containing 72 amino acids (Ser-IL-8(72)), which comprise more than 90% of IL-8 protein in cell cultures. IL-8(77) was reported to be produced predominantly by endothelial cells and is known as "endothelial" IL-8.
View Article and Find Full Text PDFPlatelet endothelial cell adhesion molecule (PECAM-1), a member of the Ig superfamily, is found on endothelial cells and neutrophils and has been shown to be involved in the migration of leukocytes across the endothelium. Adhesion is mediated, at least in part, through binding interactions involving its first N-terminal Ig-like domain, but it is still unclear which sequences in this domain are required for in vivo function. Therefore, to identify functionally important regions of the first Ig-like domain of PECAM-1 that are required for the participation of PECAM-1 in in vivo neutrophil recruitment, a panel of mAbs against this region of PECAM-1 was generated and characterized in in vitro adhesion assays and in an in vivo model of cutaneous inflammation.
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