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141.
David Safronetz Chad Mire Kyle Rosenke Friederike Feldmann Elaine Haddock Thomas Geisbert Heinz Feldmann 《PLoS neglected tropical diseases》2015,9(4)
Background
Lassa virus (LASV) is endemic in several West African countries and is the etiological agent of Lassa fever. Despite the high annual incidence and significant morbidity and mortality rates, currently there are no approved vaccines to prevent infection or disease in humans. Genetically, LASV demonstrates a high degree of diversity that correlates with geographic distribution. The genetic heterogeneity observed between geographically distinct viruses raises concerns over the potential efficacy of a “universal” LASV vaccine. To date, several experimental LASV vaccines have been developed; however, few have been evaluated against challenge with various genetically unique Lassa virus isolates in relevant animal models.Methodologies/principle findings
Here we demonstrate that a single, prophylactic immunization with a recombinant vesicular stomatitis virus (VSV) expressing the glycoproteins of LASV strain Josiah from Sierra Leone protects strain 13 guinea pigs from infection / disease following challenge with LASV isolates originating from Liberia, Mali and Nigeria. Similarly, the VSV-based LASV vaccine yields complete protection against a lethal challenge with the Liberian LASV isolate in the gold-standard macaque model of Lassa fever.Conclusions/significance
Our results demonstrate the VSV-based LASV vaccine is capable of preventing morbidity and mortality associated with non-homologous LASV challenge in two animal models of Lassa fever. Additionally, this work highlights the need for the further development of disease models for geographical distinct LASV strains, particularly those from Nigeria, in order to comprehensively evaluate potential vaccines and therapies against this prominent agent of viral hemorrhagic fever. 相似文献142.
Kyle Hubbard Phillip Beske Megan Lyman Patrick McNutt 《Journal of visualized experiments : JoVE》2015,(96)
Therapeutic and mechanistic studies of the presynaptically targeted clostridial neurotoxins (CNTs) have been limited by the need for a scalable, cell-based model that produces functioning synapses and undergoes physiological responses to intoxication. Here we describe a simple and robust method to efficiently differentiate murine embryonic stem cells (ESCs) into defined lineages of synaptically active, networked neurons. Following an 8 day differentiation protocol, mouse embryonic stem cell-derived neurons (ESNs) rapidly express and compartmentalize neurotypic proteins, form neuronal morphologies and develop intrinsic electrical responses. By 18 days after differentiation (DIV 18), ESNs exhibit active glutamatergic and γ-aminobutyric acid (GABA)ergic synapses and emergent network behaviors characterized by an excitatory:inhibitory balance. To determine whether intoxication with CNTs functionally antagonizes synaptic neurotransmission, thereby replicating the in vivo pathophysiology that is responsible for clinical manifestations of botulism or tetanus, whole-cell patch clamp electrophysiology was used to quantify spontaneous miniature excitatory post-synaptic currents (mEPSCs) in ESNs exposed to tetanus neurotoxin (TeNT) or botulinum neurotoxin (BoNT) serotypes /A-/G. In all cases, ESNs exhibited near-complete loss of synaptic activity within 20 hr. Intoxicated neurons remained viable, as demonstrated by unchanged resting membrane potentials and intrinsic electrical responses. To further characterize the sensitivity of this approach, dose-dependent effects of intoxication on synaptic activity were measured 20 hr after addition of BoNT/A. Intoxication with 0.005 pM BoNT/A resulted in a significant decrement in mEPSCs, with a median inhibitory concentration (IC50) of 0.013 pM. Comparisons of median doses indicate that functional measurements of synaptic inhibition are faster, more specific and more sensitive than SNARE cleavage assays or the mouse lethality assay. These data validate the use of synaptically coupled, stem cell-derived neurons for the highly specific and sensitive detection of CNTs. 相似文献
143.
Background
Past research linked Toxoplasma gondii (TG) infection in humans with neurological and mental disorders (e.g., schizophrenia, Alzheimer’s disease and attention disorders), irregularities of the dopaminergic and testosterone system, and increased likelihood of being involved in traffic accidents.Methodology/Principal Findings
We test for an association between TG infection and financial decision-making (DM) using a case-control design in a sample of female Czech students (n = 79). We estimate each subject''s risk attitude and loss aversion using an experimental economic task involving real monetary incentives. We find no significant evidence that either measure of decision-making is associated with TG infection.Conclusion
We were unable to find evidence of an association between TG infection and financial decision-making in females. 相似文献144.
Britney Kyle McIlvaine Lynne A. Schepartz Clark Spencer Larsen Paul W. Sciulli 《American journal of physical anthropology》2014,153(2):236-248
This article seeks to identify “Greeks” and “non‐Greeks” in “mixed” mortuary contexts in a Greek colony. Specifically, we test the hypothesis that Illyrian and Greek individuals lived and were buried together at the Corinthian colony of Apollonia, Albania (established ca. 600 BC). The pattern of human biological interaction at Apollonia is tested by identifying variation in genetic relatedness using biodistance analysis of dental and cranial nonmetric traits for three sites: Apollonia (n = 116), its founder‐city Corinth (n = 69), and Lofkënd (n = 108), an inland site near Apollonia pre‐dating colonization. Logistic regression analysis estimates that individuals from colonial Apollonia are most closely related to prehistoric Illyrian populations (from Lofkënd and prehistoric Apollonia), rather than Greeks (from Corinth). The phenotypic similarity between colonial Apollonia and prehistoric Illyria suggests that there was a large Illyrian contribution to the gene pool at the colony of Apollonia. However, some trait combinations show low biological distances among all groups, suggesting homogeneity among Illyrian and Greek populations (assessed through pseudo‐Mahalanobis' D2). The degree of phenotypic similarity suggests shared ancestry and long‐term migration throughout these regions. The impacts of missing data and small sample sizes are also considered. Am J Phys Anthropol 153:236–248, 2014. © 2013 Wiley Periodicals, Inc. 相似文献
145.
Silver nanoparticles have been modified with self-assembled monolayers of hydroxyl-terminated long chain thiols and encapsulated with a silica shell. The resulting core–shell nanoparticles were used as optical labels for cell analysis using flow cytometry and microscopy. The excitation of plasmon resonances in nanoparticles results in strong depolarized scattering of visible light, permitting detection at the single nanoparticle level. The nanoparticles were modified with neutravidin via epoxide–azide coupling chemistry, to which biotinylated antibodies targeting cell surface receptors were bound. The nanoparticle labels exhibited long-term stability in solutions with high salt concentrations without aggregation or silver etching. Labeled cells exhibited two orders of magnitude enhancement of the scattering intensity compared with unlabeled cells. 相似文献
146.
147.
Hilde Herrema Jaemin LeeYingjiang Zhou Kyle D. CoppsMorris F. White Umut Ozcan 《Biochemical and biophysical research communications》2014
Increased mammalian target of rapamycin complex 1 (mTORC1) activity has been suggested to play important roles in development of insulin resistance in obesity. mTORC1 hyperactivity also increases endoplasmic reticulum (ER) stress, which in turn contributes to development of insulin resistance and glucose intolerance. Increased IRS1 phosphorylation at Ser307 in vitro is correlated with mTORC1- and ER stress-induced insulin resistance. This phosphorylation site correlates strongly with impaired insulin receptor signaling in diabetic mice and humans. In contrast, evidence from knock-in mice suggests that phosphorylation of IRS1 at Ser307 is actually required to maintain insulin sensitivity. To study the involvement of IRS1Ser307 phosphorylation in mTORC1-mediated glucose intolerance and insulin sensitivity in vivo, we investigated the effects of liver specific TSC1 depletion in IRS1Ser307Ala mice and controls. Our results demonstrate that blockade of IRS1Ser307 phosphorylation in vivo does not prevent mTORC1-mediated glucose intolerance and insulin resistance. 相似文献
148.
149.
Sumei Liao Marlise I. Klein Kyle P. Heim Yuwei Fan Jacob P. Bitoun San-Joon Ahn Robert A. Burne Hyun Koo L. Jeannine Brady Zezhang T. Wen 《Journal of bacteriology》2014,196(13):2355-2366
Streptococcus mutans, a major etiological agent of human dental caries, lives primarily on the tooth surface in biofilms. Limited information is available concerning the extracellular DNA (eDNA) as a scaffolding matrix in S. mutans biofilms. This study demonstrates that S. mutans produces eDNA by multiple avenues, including lysis-independent membrane vesicles. Unlike eDNAs from cell lysis that were abundant and mainly concentrated around broken cells or cell debris with floating open ends, eDNAs produced via the lysis-independent pathway appeared scattered but in a structured network under scanning electron microscopy. Compared to eDNA production of planktonic cultures, eDNA production in 5- and 24-h biofilms was increased by >3- and >1.6-fold, respectively. The addition of DNase I to growth medium significantly reduced biofilm formation. In an in vitro adherence assay, added chromosomal DNA alone had a limited effect on S. mutans adherence to saliva-coated hydroxylapatite beads, but in conjunction with glucans synthesized using purified glucosyltransferase B, the adherence was significantly enhanced. Deletion of sortase A, the transpeptidase that covalently couples multiple surface-associated proteins to the cell wall peptidoglycan, significantly reduced eDNA in both planktonic and biofilm cultures. Sortase A deficiency did not have a significant effect on membrane vesicle production; however, the protein profile of the mutant membrane vesicles was significantly altered, including reduction of adhesin P1 and glucan-binding proteins B and C. Relative to the wild type, deficiency of protein secretion and membrane protein insertion machinery components, including Ffh, YidC1, and YidC2, also caused significant reductions in eDNA. 相似文献
150.
Chung-Jr Huang Kyle A. Anderson Leonardo M. Damasceno Gerd Ritter Lloyd J. Old Carl A. Batt 《Applied microbiology and biotechnology》2010,86(1):243-253
The cancer-testis (CT) antigen synovial sarcoma X break point 2 (SSX2) was expressed in Pichia pastoris as a means to produce a delayed-type hypersensitivity skin test reagent for monitoring SSX2-specific anti-cancer immune responses.
SSX2 was detected intracellularly in P. pastoris despite the addition of the Saccharomyces cerevisiae alpha-mating factor secretion signal. Increasing the SSX2 gene copy number did not improve its secretion but did enhance
intracellular SSX2 levels. SSX2 with its C-terminal nuclear localization signal (NLS) deleted (SSX2NORD), however, was secreted.
Indirect immunofluorescence indicated that SSX2 containing the NLS did not translocate to the nucleus but accumulated in the
endoplasmic reticulum (ER). Experimental results further suggested that SSX2 containing the NLS was misfolded in the ER, while
deletion of the NLS facilitated correct folding of SSX2 inside the ER and improved its secretion. Production of SSX2NORD was
scaled-up to a 2-L fermentor using a fed-batch protocol to maintain methanol at a concentration of 1 g L−1. Decreasing the cultivation temperature from 25 °C to 16 °C improved protein stability in the culture supernatant. In this
process, after 120 h cultivation, the wet cell weight of P. pastoris reached 280 mg mL−1, and the yield of SSX2NORD was 21.6 mg L−1. 相似文献