28 research outputs found

    Increased mitochondrial DNA diversity in ancient Columbia River basin Chinook salmon Oncorhynchus tshawytscha

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    The Columbia River and its tributaries provide essential spawning and rearing habitat for many salmonid species, including Chinook salmon (Oncorhynchus tshawytscha). Chinook salmon were historically abundant throughout the basin and Native Americans in the region relied heavily on these fish for thousands of years. Following the arrival of Europeans in the 1800s, salmon in the basin experienced broad declines linked to overfishing, water diversion projects, habitat destruction, connectivity reduction, introgression with hatchery-origin fish, and hydropower development. Despite historical abundance, many native salmonids are now at risk of extinction. Research and management related to Chinook salmon is usually explored under what are termed “the four H’s”: habitat, harvest, hatcheries, and hydropower; here we explore a fifth H, history. Patterns of prehistoric and contemporary mitochondrial DNA variation from Chinook salmon were analyzed to characterize and compare population genetic diversity prior to recent alterations and, thus, elucidate a deeper history for this species. A total of 346 ancient and 366 contemporary samples were processed during this study. Species was determined for 130 of the ancient samples and control region haplotypes of 84 of these were sequenced. Diversity estimates from these 84 ancient Chinook salmon were compared to 379 contemporary samples. Our analysis provides the first direct measure of reduced genetic diversity for Chinook salmon from the ancient to the contemporary period, as measured both in direct loss of mitochondrial haplotypes and reductions in haplotype and nucleotide diversity. However, these losses do not appear equal across the basin, with higher losses of diversity in the mid-Columbia than in the Snake subbasin. The results are unexpected, as the two groups were predicted to share a common history as parts of the larger Columbia River Basin, and instead indicate that Chinook salmon in these subbasins may have divergent demographic histories.Ye

    Ion-assisted deposition processes: Industrial network IntIon

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    The presented work is embedded in the research network "Integrative Ion Processes for Modern Optics", called IntIon, consisting of 12 partners from the German optics industry and two research institutes. The main target of the IntIon network is the development of new process concepts on the basis of ion assisted deposition (IAD) for the industrial production of optical thin film components. Besides an improvement in efficiency, a major aim is concentrated on the optical characteristics for selected application fields with high economical potential. In this network, different ion and plasma sources are compared with regard to their qualification for ion assisted deposition processes. This work includes the characterization of the ion energy and ion current using Faraday-cup measurements. The selection of investigated coating materials includes a broad variety of standard and non-standard oxides. First results of the network will be presented for adapted deposition materials and different operation characteristics of ion sources

    Characterization and Comparison of GITR Expression in Solid Tumors

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    Abstract Purpose: Determine the differential effect of a FcγR-binding, mIgG2a anti-GITR antibody in mouse tumor models, and characterize the tumor microenvironment for the frequency of GITR expression in T-cell subsets from seven different human solid tumors. Experimental Design: For mouse experiments, wild-type C57BL/6 mice were subcutaneously injected with MC38 cells or B16 cells, and BALB/c mice were injected with CT26 cells. Mice were treated with the anti-mouse GITR agonist antibody 21B6, and tumor burden and survival were monitored. GITR expression was evaluated at the single-cell level using flow cytometry (FC). A total of 213 samples were evaluated for GITR expression by IHC, 63 by FC, and 170 by both in seven human solid tumors: advanced hepatocellular carcinoma, non–small cell lung cancer (NSCLC), renal cell carcinoma, pancreatic carcinoma, head and neck carcinoma, melanoma, and ovarian carcinoma. Results: The therapeutic benefit of 21B6 was greatest in CT26 followed by MC38, and was least in the B16 tumor model. The frequency of CD8 T cells and effector CD4 T cells within the immune infiltrate correlated with response to treatment with GITR antibody. Analysis of clinical tumor samples showed that NSCLC, renal cell carcinoma, and melanoma had the highest proportions of GITR-expressing cells and highest per-cell density of GITR expression on CD4+ Foxp3+ T regulatory cells. IHC and FC data showed similar trends with a good correlation between both techniques. Conclusions: Human tumor data suggest that NSCLC, renal cell carcinoma, and melanoma should be the tumor subtypes prioritized for anti-GITR therapy development. </jats:sec

    Human Responses to Influenza Vaccination Show Seroconversion Signatures and Convergent Antibody Rearrangements

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    SummaryB cells produce a diverse antibody repertoire by undergoing gene rearrangements. Pathogen exposure induces the clonal expansion of B cells expressing antibodies that can bind the infectious agent. To assess human B cell responses to trivalent seasonal influenza and monovalent pandemic H1N1 vaccination, we sequenced gene rearrangements encoding the immunoglobulin heavy chain, a major determinant of epitope recognition. The magnitude of B cell clonal expansions correlates with an individual’s secreted antibody response to the vaccine, and the expanded clones are enriched with those expressing influenza-specific monoclonal antibodies. Additionally, B cell responses to pandemic influenza H1N1 vaccination and infection in different people show a prominent family of convergent antibody heavy chain gene rearrangements specific to influenza antigens. These results indicate that microbes can induce specific signatures of immunoglobulin gene rearrangements and that pathogen exposure can potentially be assessed from B cell repertoires

    Increased half-life and enhanced potency of Fc-modified human PCSK9 monoclonal antibodies in primates

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    Blocking proprotein convertase subtilisin kexin type 9 (PCSK9) binding to low-density lipoprotein receptor (LDLR) can profoundly lower plasma LDL levels. Two anti-PCKS9 monoclonal antibodies (mAbs), alirocumab and evolocumab, were approved by the FDA in 2015. The recommended dose is 75 mg to 150 mg every two weeks for alirocumab and 140mg every two weeks or 420 mg once a month for evolocumab. This study attempted to improve the pharmacokinetic properties of F0016A, an IgG1 anti-PCKS9 mAb, to generate biologically superior molecules. We engineered several variants with two or three amino acid substitutions in the Fc fragment based on prior knowledge. The Fc-modified mAbs exhibited increased binding to FcRn, resulting in prolonged serum half-life and enhanced efficacy in vivo. These results demonstrate that Fc-modified anti-PCKS9 antibodies may enable less frequent or lower dosing of antibodies by improved recycling into the blood
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