65 research outputs found

    In vivo function of the lipid raft protein flotillin-1 during cd8+ t cell–mediated host surveillance

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    Flotillin-1 (Flot1) is an evolutionary conserved, ubiquitously expressed lipid raft– associated scaffolding protein. Migration of Flot1-deficient neutrophils is impaired because of a decrease in myosin II–mediated contractility. Flot1 also accumulates in the uropod of polarized T cells, suggesting an analogous role in T cell migration. In this study, we analyzed morphology and migration parameters of murine wild-type and Flot1−/− CD8+ T cells using in vitro assays and intravital two-photon microscopy of lymphoid and nonlymphoid tissues. Flot1−/− CD8+ T cells displayed significant alterations in cell shape and motility parameters in vivo but showed comparable homing to lymphoid organs and intact in vitro migration to chemokines. Furthermore, their clonal expansion and infiltration into nonlymphoid tissues during primary and secondary antiviral immune responses was comparable to wild-type CD8+ T cells. Taken together, Flot1 plays a detectable but unexpectedly minor role for CD8+ T cell behavior under physiological conditions

    The Inflammatory Kinase MAP4K4 Promotes Reactivation of Kaposi's Sarcoma Herpesvirus and Enhances the Invasiveness of Infected Endothelial Cells

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    Kaposi's sarcoma (KS) is a mesenchymal tumour, which is caused by Kaposi's sarcoma herpesvirus (KSHV) and develops under inflammatory conditions. KSHV-infected endothelial spindle cells, the neoplastic cells in KS, show increased invasiveness, attributed to the elevated expression of metalloproteinases (MMPs) and cyclooxygenase-2 (COX-2). The majority of these spindle cells harbour latent KSHV genomes, while a minority undergoes lytic reactivation with subsequent production of new virions and viral or cellular chemo- and cytokines, which may promote tumour invasion and dissemination. In order to better understand KSHV pathogenesis, we investigated cellular mechanisms underlying the lytic reactivation of KSHV. Using a combination of small molecule library screening and siRNA silencing we found a STE20 kinase family member, MAP4K4, to be involved in KSHV reactivation from latency and to contribute to the invasive phenotype of KSHV-infected endothelial cells by regulating COX-2, MMP-7, and MMP-13 expression. This kinase is also highly expressed in KS spindle cells in vivo. These findings suggest that MAP4K4, a known mediator of inflammation, is involved in KS aetiology by regulating KSHV lytic reactivation, expression of MMPs and COX-2, and, thereby modulating invasiveness of KSHV-infected endothelial cells. © 2013 Haas et al

    Digitization Workflows for Flat Sheets and Packets of Plants, Algae, and Fungi

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    Effective workflows are essential components in the digitization of biodiversity specimen collections. To date, no comprehensive, community-vetted workflows have been published for digitizing flat sheets and packets of plants, algae, and fungi, even though latest estimates suggest that only 33% of herbarium specimens have been digitally transcribed, 54% of herbaria use a specimen database, and 24% are imaging specimens. In 2012, iDigBio, the U.S. National Science Foundation’s (NSF) coordinating center and national resource for the digitization of public, nonfederal U.S. collections, launched several working groups to address this deficiency. Here, we report the development of 14 workflow modules with 7–36 tasks each. These workflows represent the combined work of approximately 35 curators, directors, and collections managers representing more than 30 herbaria, including 15 NSF-supported plant-related Thematic Collections Networks and collaboratives. The workflows are provided for download as Portable Document Format (PDF) and Microsoft Word files. Customization of these workflows for specific institutional implementation is encouraged

    PHLOX VERMEJOENSIS (POLEMONIACEAE), A NEW SPECIES FROM NORTHERN NEW MEXICO, U.S.A

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    Volume: 5Start Page: 397End Page: 40

    Two new species of Sabulina (Caryophyllaceae) from Washington State, U.S.A.

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    Sabulina basaltica and Sabulina sororia (Caryophyllaceae) are described as new species endemic to Washington State, U.S.A. Sabulina basaltica is restricted to high-elevation, basalt rocks in the northeastern Olympic Mountains, and Sabulina sororia to high-elevation, dunite rocks of the Twin Sisters Range in the North Cascade Mountains. Both were previously confused with Sabulina rossii (formerly called Arenaria rossii or Minuartia rossii). Their recognition as distinct species is supported by morphological and molecular characters and disjunct geographic distributions. Both are illustrated, mapped and compared to related species. We also present a molecular phylogeny of Sabulina based on nuclear ITS and plastid trnQ-rps16 DNA with increased sampling of North American taxa. The phylogeny resolves a single clade containing all glabrous, perennial, North American Sabulina taxa including Sabulina rossii and both of the new species

    A Vascular Flora of the Selkirk Mountains, Bonner and Boundary Counties, Idaho

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    The vascular flora described here covers ~2295 square kilometers (~886 square miles) of the Selkirk Mountains that lie in the Idaho Panhandle, covering an elevational range of 540–2330 m (1770–7670 ft). The majority of the mountain range is underlain by granitic rock of the Kaniksu Batholith, and is diversified by the rich glacial history of the Panhandle. The study area contains multiple pockets of alluvial and glacial deposition that serve as specialized habitat for present-day floristic diversity within the range. The Idaho Selkirks are part of the Northern Rocky Mountains and have floristic influences from the Pacific coast, boreal north, the Columbia Basin, and the Rocky Mountains to the south and east. Despite notable collection interest over the last century in the northern Idaho Panhandle, a comprehensive checklist did not exist prior to this project, and previous collecting efforts were uneven, creating significant gaps in coverage and incomplete documentation of the area. A total of 108 collection days were spent in the field in 2019 and 2020, resulting in 4155 vascular plant collections from 665 collection sites, documenting 845 total unique taxa in 94 plant families. Taxa previously collected but not recovered were first verified by the author using historical specimens housed at multiple Pacific Northwest herbaria, and were then included in the final checklist. Sixty-two rare taxa and six state collection records were found in the study area, as well as numerous range extensions and county collection records. While the primary objective was to document and voucher all vascular plant taxa of the Selkirk Mountains of Idaho to create an annotated checklist of the vascular flora, additional objectives included formal assessments of the vegetation types and threats to the flora of the study area, as well as increasing documentation of sensitive, rare, and non-native species occurrences within the range

    Molecular analysis of D-negative phenotype in the Tunisian population

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    International audienceBackground: Most studies of the molecular basis of Rhesus D-negative phenotype have been conducted in Caucasian and African populations. A comprehensive survey of RHD alleles was lacking in people from North Africa (Tunisians, Moroccans and Algerians) which could be very efficient for managing donors and patients carrying an RHD molecular variant. We analyse the molecular background of D-negative population in Tunisia in the present study. Materials and methods: Blood samples were collected from native Tunisians. A total of 448 D-negative donors from different regions of Tunisia were analysed by RHD genotyping according to an adopted strategy using real-time PCR, ASP-PCR and sequencing. Results: Among the 448 D-negative samples, 443 were phenotyped unequivocally as true D-negative including three molecular backgrounds which were RHD gene deletion (n = 437), RHDψ pseudogene (n = 2) and RHD-CE-D hybrid gene (n = 4) with the respective frequencies of 0*9900, 0*0023 and 0*0046. The remaining five samples, in discordance with the serological results, were identified as two weak D type 11, one weak D type 29, one weak D type 4*0 and one DBT-1 partial D. Conclusion: This study showed that the Tunisian population gets closer to Caucasians, given that the RHD gene deletion is the most prevalent cause of D-negative phenotype, but it is slightly different by the presence of the RHDψ pseudogene which was found with a very low frequency compared with that described in the African population. Nevertheless, the relative occurrence of weak D variants among studied serologically D-negative samples make necessary the adaptation of RHD genotyping strategy to the spectrum of prevalent alleles
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