bluuebunny/crossref_metadata_2025_split huggingface dataset:
Overexpression of human virus surface glycoprotein precursors induces cytosolic unfolded protein response in Saccharomyces cerevisiae
Authors: Čiplys Evaldas , Samuel Dhanraj , Juozapaitis Mindaugas , Sasnauskas Kęstutis , Slibinskas Rimantas 
Published: May 2011

AbstractBackgroundThe expression of human virus surface proteins, as well as other mammalian glycoproteins, is much more efficient in cells of higher eukaryotes rather than yeasts. The limitations to high-level expression of active viral surface glycoproteins in yeast are not well understood. To identify possible bottlenecks we performed a detailed study on overexpression of recombinant mumps hemagglutinin-neuraminidase (MuHN) and measles hemagglutinin (MeH) in yeastSaccharomyces cerevisiae, combining the analysis of recombinant proteins with a proteomic approach.ResultsOverexpressed recombinant MuHN and MeH proteins were present in large aggregates, were inactive and totally insoluble under native conditions. Moreover, the majority of recombinant protein was found in immature form of non-glycosylated precursors. Fractionation of yeast lysates revealed that the core of viral surface protein aggregates consists of MuHN or MeH disulfide-linked multimers involving eukaryotic translation elongation factor 1A (eEF1A) and is closely associated with small heat shock proteins (sHsps) that can be removed only under denaturing conditions. Complexes of large Hsps seem to be bound to aggregate core peripherally as they can be easily removed at high salt concentrations. Proteomic analysis revealed that the accumulation of unglycosylated viral protein precursors results in specific cytosolic unfolded protein response (UPR-Cyto) in yeast cells, characterized by different action and regulation of small Hsps versus large chaperones of Hsp70, Hsp90 and Hsp110 families. In contrast to most environmental stresses, in the response to synthesis of recombinant MuHN and MeH, only the large Hsps were upregulated whereas sHsps were not. Interestingly, the amount of eEF1A was also increased during this stress response.ConclusionsInefficient translocation of MuHN and MeH precursors through ER membrane is a bottleneck for high-level expression in yeast. Overexpression of these recombinant proteins induces the UPR's cytosolic counterpart, the UPR-Cyto, which represent a subset of proteins involved in the heat-shock response. The involvement of eEF1A may explain the mechanism by which only large chaperones, but not small Hsps are upregulated during this stress response. Our study highlights important differences between viral surface protein expression in yeast and mammalian cells at the first stage of secretory pathway.
Possible role of death receptor-mediated apoptosis by the E3 ubiquitin ligases Siah2 and POSH
Authors: Christian Perry A , Fiandalo Michael V , Schwarze Steven R 
Published: May 2011

Abstract

Background
A functioning ubiquitin proteasome system (UPS) is essential for a number of diverse cellular processes and maintenance of overall cellular homeostasis. The ability of proteasome inhibitors, such as Velcade, to promote extrinsic apoptotic effects illustrates the importance of the ubiquitin proteasome system in the regulation of death receptor signaling. Here, we set out to define the UPS machinery, particularly the E3 ubiquitin ligases, that repress apoptosis through the extrinsic pathway. A cell-based genome-wide E3 ligase siRNA screen was established to monitor caspase-8 activity following the addition of TRAIL.

Results
Data from the high-throughput screen revealed that targeting the RING-finger containing E3 ligase Siah2 as well as the signaling platform molecule POSH (SH3RF1) conferred robust caspase-8 activation in response to TRAIL stimulus. Silencing Siah2 or POSH in prostate cancer cells led to increased caspase activity and apoptosis in response to both TRAIL and Fas ligand. The E3 activity of Siah2 was responsible for mediating apoptosis resistance; while POSH protein levels were critical for maintaining viability. Further characterization of Siah2 revealed it to function downstream of early death receptor events in the apoptotic pathway. The observed apoptosis resistance provides one biological explanation for the induction of Siah2 and POSH reported in lung and prostate cancer, respectively. Expanding on an initial yeast-two-hybrid screen we have confirmed a physical interaction between E3 ligases Siah2 and POSH. Utilizing a yeast-two-hybrid mapping approach we have defined the spacer region of POSH, more specifically the RPxAxVxP motif encompassing amino acids 601-607, to be the site of Siah2 binding.

Conclusions
The data presented here define POSH and Siah2 as important mediators of death receptor mediated apoptosis and suggest targeting the interaction of these two E3 ligases is a promising novel cancer therapeutic strategy.
Recombinant HPV16 E7 assembled into particles induces an immune response and specific tumour protection administered without adjuvant in an animal model
Authors: Petrone Linda , Ammendolia Maria G , Cesolini Armando , Caimi Stefano , Superti Fabiana , Giorgi Colomba , Di Bonito Paola 
Published: May 2011

Abstract

Background
The HPV16 E7 protein is both a tumour-specific and a tumour-rejection antigen, the ideal target for developing therapeutic vaccines for the treatment of HPV16-associated cancer and its precursor lesions. E7, which plays a key role in virus-associated carcinogenesis, contains 98 amino acids and has two finger-type structures which bind a Zn++ ion. The ability of an Escherichia coli-produced E7-preparation, assembled into particles, to induce protective immunity against a HPV16-related tumour in the TC-1-C57BL/6 mouse tumour model, was evaluated.

Methods
E7 was expressed in E. coli, purified via a one-step denaturing protocol and prepared as a soluble suspension state after dialysis in native buffer. The presence in the E7 preparation of particulate forms was analysed by non-reducing SDS-PAGE and negative staining electron microscopy (EM). The Zn++ ion content was analysed by mass-spectrometry. Ten μg of protein per mouse was administered to groups of animals, once, twice or three times without adjuvant. The E7-specific humoral response was monitored in mice sera using an E7-based ELISA while the cell-mediated immune response was analysed in mice splenocytes with lymphoproliferation and IFN-γ ELISPOT assays. The E7 immunized mice were challenged with TC-1 tumour cells and the tumour growth monitored for two months.

Results
In western blot analysis E7 appears in multimers and high molecular mass oligomers. The EM micrographs show the protein dispersed as aggregates of different shape and size. The protein appears clustered in micro-, nano-aggregates, and structured particles. Mice immunised with this protein preparation show a significant E7-specific humoral and cell-mediated immune response of mixed Th1/Th2 type. The mice are fully protected from the tumour growth after vaccination with three E7-doses of 10 μg without any added adjuvant.

Conclusions
This report shows that a particulate form of HPV16 E7 is able to induce, without adjuvant, an E7-specific tumour protection in C57BL/6 mice. The protective immunity is sustained by both humoral and cell-mediated immune responses. The E. coli-derived HPV16 E7 assembled in vitro into micro- and nanoparticles represents not only a good substrate for antigen-presenting cell uptake and processing, but also a cost-effective means for the production of a new generation of HPV subunit vaccines.
Negative enrichment by immunomagnetic nanobeads for unbiased characterization of circulating tumor cells from peripheral blood of cancer patients
Authors: Liu Zhian , Fusi Alberto , Klopocki Eva , Schmittel Alexander , Tinhofer Ingeborg , Nonnenmacher Anika , Keilholz Ulrich 
Published: May 2011

Abstract

Background
A limitation of positive selection strategies to enrich for circulating tumor cells (CTCs) is that there might be CTCs with insufficient expression of the surface target marker which may be missed by the procedure. We optimized a method for enrichment, subsequent detection and characterization of CTCs based on depletion of the leukocyte fraction.

Methods
The 2-step protocol was developed for processing 20 mL blood and based on red blood cell lysis followed by leukocyte depletion. The remaining material was stained with the epithelial markers EpCAM and cytokeratin (CK) 7/8 or for the melanoma marker HMW-MAA/MCSP. CTCs were detected by flow cytometry. CTCs enriched from blood of patients with carcinoma were defined as EpCAM+CK+CD45-. CTCs enriched from blood of patients with melanoma were defined as MCSP+CD45-. One-hundred-sixteen consecutive blood samples from 70 patients with metastatic carcinomas (n = 48) or metastatic melanoma (n = 22) were analyzed.

Results
CTCs were detected in 47 of 84 blood samples (56%) drawn from carcinoma patients, and in 17 of 32 samples (53%) from melanoma patients. CD45-EpCAM-CK+ was detected in pleural effusion specimens, as well as in peripheral blood samples of patients with NSCLC. EpCAM-CK+ cells have been successfully cultured and passaged longer than six months suggesting their neoplastic origin. This was confirmed by CGH. By defining CTCs in carcinoma patients as CD45-CK+ and/or EpCAM+, the detection rate increased to 73% (61/84).

Conclusion
Enriching CTCs using CD45 depletion allowed for detection of epithelial cancer cells not displaying the classical phenotype. This potentially leads to a more accurate estimation of the number of CTCs. If detection of CTCs without a classical epithelial phenotype has clinical relevance need to be determined.
Exacerbation of CNS inflammation and neurodegeneration by systemic LPS treatment is independent of circulating IL-1β and IL-6
Authors: Murray Carol L , Skelly Donal T , Cunningham Colm 
Published: May 2011

Abstract

Background
Chronic neurodegeneration comprises an inflammatory response but its contribution to the progression of disease remains unclear. We have previously shown that microglial cells are primed by chronic neurodegeneration, induced by the ME7 strain of prion disease, to synthesize limited pro-inflammatory cytokines but to produce exaggerated responses to subsequent systemic inflammatory insults. The consequences of this primed response include exaggerated hypothermic and sickness behavioural responses, acute neuronal death and accelerated progression of disease. Here we investigated whether inhibition of systemic cytokine synthesis using the anti-inflammatory steroid dexamethasone-21-phosphate was sufficient to block any or all of these responses.

Methods
ME7 animals, at 18-19 weeks post-inoculation, were challenged with LPS (500 μg/kg) in the presence or absence of dexamethasone-21-phosphate (2 mg/kg) and effects on core-body temperature and systemic and CNS cytokine production and apoptosis were examined.

Results
LPS induced hypothermia and decreased exploratory activity. Dexamethasone-21-phosphate prevented this hypothermia, markedly suppressed systemic IL-1β and IL-6 secretion but did not prevent decreased exploration. Furthermore, robust transcription of cytokine mRNA occurred in the hippocampus of both ME7 and NBH (normal brain homogenate) control animals despite the effective blocking of systemic cytokine synthesis. Microglia primed by neurodegeneration were not blocked from the robust synthesis of IL-1β protein and endothelial COX-2 was also robustly synthesized. We injected biotinylated LPS at 100 μg/kg and even at this lower dose this could be detected in blood plasma. Apoptosis was acutely induced by LPS, despite the inhibition of the systemic cytokine response.

Conclusions
These data suggest that LPS can directly activate the brain endothelium even at relatively low doses, obviating the need for systemic cytokine stimulation to transduce systemic inflammatory signals into the brain or to exacerbate existing pathology.
Changes in interleukin-1 signal modulators induced by 3,4-methylenedioxymethamphetamine (MDMA): regulation by CB2 receptors and implications for neurotoxicity
Authors: Torres Elisa , Gutierrez-Lopez Maria D , Mayado Andrea , Rubio Ana , O'Shea Esther , Colado Maria I 
Published: May 2011

Abstract

Background
3,4-Methylenedioxymethamphetamine (MDMA) produces a neuroinflammatory reaction in rat brain characterized by an increase in interleukin-1 beta (IL-1β) and microglial activation. The CB2 receptor agonist JWH-015 reduces both these changes and partially protects against MDMA-induced neurotoxicity. We have examined MDMA-induced changes in IL-1 receptor antagonist (IL-1ra) levels and IL-1 receptor type I (IL-1RI) expression and the effects of JWH-015. The cellular location of IL-1β and IL-1RI was also examined. MDMA-treated animals were given the soluble form of IL-1RI (sIL-1RI) and neurotoxic effects examined.

Methods
Dark Agouti rats received MDMA (12.5 mg/kg, i.p.) and levels of IL-1ra and expression of IL-1RI measured 1 h, 3 h or 6 h later. JWH-015 (2.4 mg/kg, i.p.) was injected 48 h, 24 h and 0.5 h before MDMA and IL-1ra and IL-1RI measured. For localization studies, animals were sacrificed 1 h or 3 h following MDMA and stained for IL-1β or IL-1RI in combination with neuronal and microglial markers. sIL-1RI (3 μg/animal; i.c.v.) was administered 5 min before MDMA and 3 h later. 5-HT transporter density was determined 7 days after MDMA injection.

Results
MDMA produced an increase in IL-ra levels and a decrease in IL-1RI expression in hypothalamus which was prevented by CB2 receptor activation. IL-1RI expression was localized on neuronal cell bodies while IL-1β expression was observed in microglial cells following MDMA. sIL-1RI potentiated MDMA-induced neurotoxicity. MDMA also increased IgG immunostaining indicating that blood brain-barrier permeability was compromised.

Conclusions
In summary, MDMA produces changes in IL-1 signal modulators which are modified by CB2 receptor activation. These results indicate that IL-1β may play a partial role in MDMA-induced neurotoxicity.
Latent Membrane Protein 1 as a molecular adjuvant for single-cycle lentiviral vaccines
Authors: Gupta Sachin , Termini James M , Niu Liguo , Kanagavelu Saravana K , Rahmberg Andrew R , Kornbluth Richard S , Evans David T , Stone Geoffrey W 
Published: May 2011

AbstractBackgroundMolecular adjuvants are a promising method to enhance virus-specific immune responses and protect against HIV-1 infection. Immune activation by ligands for receptors such as CD40 can induce dendritic cell activation and maturation. Here we explore the incorporation of two CD40 mimics, Epstein Barr Virus gene LMP1 or an LMP1-CD40 chimera, into a strain of SIV that was engineered to be limited to a single cycle of infection.ResultsFull length LMP1 or the chimeric protein LMP1-CD40 was cloned into thenef-locus of single-cycle SIV. Human and Macaque monocyte derived macrophages and DC were infected with these viruses. Infected cells were analyzed for activation surface markers by flow cytometry. Cells were also analyzed for secretion of pro-inflammatory cytokines IL-1β, IL-6, IL-8, IL-12p70 and TNF by cytometric bead array.ConclusionsOverall, single-cycle SIV expressing LMP1 and LMP1-CD40 produced a broad and potent TH1-biased immune response in human as well as rhesus macaque macrophages and DC when compared with control virus. Single-cycle SIV-LMP1 also enhanced antigen presentation by lentiviral vector vaccines, suggesting that LMP1-mediated immune activation may enhance lentiviral vector vaccines against HIV-1.
Effect of human activated NRAS on replication of delNS1 H5N1 influenza virus in MDCK cells
Authors: Zhu Jiping , Zhou HongBo , Zou Wei , Jin MeiLin 
Published: May 2011

Abstract

Background
RAS, coded by ras proto-oncogenes, played an important role in signal transmission to regulate cell growth and differentiation. Host activation of RAS was significant for IFN-sensitive vaccinia virus (delE3L) or attenuate influenza virus in unallowable cells.

Results
Huamn NRAS gene was activated by mutating in codon 61. Then the activation of NRAS was detected by western blot in MDCK cells. The delNS1 H5N1 influenza virus with deletion of NS1 eIF4GI binding domain was weak multiplication in MDCK cells. And the replication of delNS1 virus and expression of IFN-beta and IRF-3 were detected by Real-time PCR in MDCK cells infected with delNS1 virus. It was found that the delNS1 virus had a significant increase in MDCK cells when the NRAS was activated, and yet, expression of IRF-3 and IFN-beta were restrained.

Conclusions
The study demonstrated that activated NRAS played an important part for delNS1 virus replication in MDCK cells. Activated NRAS might be down-regulating the expression of antiviral cellular factors in delNS1 virus infected cells.
Expression and characterization of duck enteritis virus gI gene
Authors: Li Lijuan , Cheng Anchun , Wang Mingshu , Xiang Jun , Yang Xiaoyuan , Zhang Shunchuan , Zhu Dekang , Jia Renyong , Luo Qihui , Zhou Yi , Chen Zhengli , Chen Xiaoyue 
Published: May 2011

Abstract

Background
At present, alphaherpesviruses gI gene and its encoding protein have been extensively studied. It is likely that gI protein and its homolog play similar roles in virions direct cell-to-cell spread of alphaherpesviruses. But, little is known about the characteristics of DEV gI gene. In this study, we expressed and presented the basic properties of the DEV gI protein.

Results
The special 1221-bp fragment containing complete open reading frame(ORF) of duck enteritis virus(DEV) gI gene was extracted from plasmid pMD18-T-gI, and then cloned into prokaryotic expression vector pET-32a(+), resulting in pET-32a(+)-gI. After being confirmed by PCR, restriction endonuclease digestion and sequencing, pET-32a(+)-gI was transformed into E.coli BL21(DE3) competent cells for overexpression. DEV gI gene was successfully expressed by the addition of isopropyl-β-D-thiogalactopyranoside(IPTG). SDS-PAGE showed that the recombinant protein His6-tagged gI molecular weight was about 61 kDa. Subsequently, the expressed product was applied to generate specific antibody against gI protein. The specificity of the rabbit immuneserum was confirmed by its ability to react with the recombinant protein His6-tagged gI. In addition, real time-PCR was used to determine the the levels of the mRNA transcripts of gI gene, the results showed that the DEV gI gene was transcribed most abundantly during the late phase of infection. Furthermore, indirect immunofluorescence(IIF) was established to study the gI protein expression and localization in DEV-infected duck embryo fibroblasts (DEFs), the results confirmed that the protein was expressed and located in the cytoplasm of the infected cells, intensively.

Conclusions
The recombinant prokaryotic expression vector of DEV gI gene was constructed successfully. The gI protein was successfully expressed by E.coli BL21(DE3) and maintained its antigenicity very well. The basic information of the transcription and intracellular localization of gI gene were presented, that would be helpful to assess the possible role of DEV gI gene. The research will provide useful clues for further functional analysis of DEV gI gene.
Homer1a Signaling in the Amygdala Counteracts Pain-Related Synaptic Plasticity, mGluR1 Function and Pain Behaviors
Authors: Tappe-Theodor Anke , Fu Yu , Kuner Rohini , Neugebauer Volker 
Published: May 2011

Background: Group I metabotropic glutamate receptor (mGluR1/5) signaling is an important mechanism of pain-related plasticity in the amygdala that plays a key role in the emotional-affective dimension of pain. Homer1a, the short form of the Homer1 family of scaffolding proteins, disrupts the mGluR-signaling complex and negatively regulates nociceptive plasticity at spinal synapses. Using transgenic mice overexpressing Homer1a in the forebrain (H1a-mice), we analyzed synaptic plasticity, pain behavior and mGluR1 function in the basolateral amygdala (BLA) in a model of arthritis pain. Findings: In contrast to wild-type mice, H1a-mice mice did not develop increased pain behaviors (spinal reflexes and audible and ultrasonic vocalizations) after induction of arthritis in the knee joint. Whole-cell patch-clamp recordings in brain slices showed that excitatory synaptic transmission from the BLA to the central nucleus (CeA) did not change in arthritic H1a-mice but increased in arthritic wild-type mice. A selective mGluR1 antagonist (CPCCOEt) had no effect on enhanced synaptic transmission in slices from H1a-BLA mice with arthritis but inhibited transmission in wild-type mice with arthritis as in our previous studies in rats. Conclusions: The results show that Homer1a expressed in forebrain neurons, prevents the development of pain hypersensitivity in arthritis and disrupts pain-related plasticity at synapses in amygdaloid nuclei. Furthermore, Homer1a eliminates the effect of an mGluR1 antagonist, which is consistent with the well-documented disruption of mGluR1 signaling by Homer1a. These findings emphasize the important role of mGluR1 in pain-related amygdala plasticity and provide evidence for the involvement of Homer1 proteins in the forebrain in the modulation of pain hypersensitivity.
Regional Chemotherapy in Locally Advanced Pancreatic Cancer: RECLAP Trial
Authors: Davis Jeremy L , Pandalai Prakash , Ripley R Taylor , Langan Russell C , Steinberg Seth M , Walker Melissa , Toomey Mary Ann , Levy Elliot , Avital Itzhak 
Published: May 2011

Abstract

Background
Pancreatic cancer is the fourth leading cause of cancer death in the United States. Surgery offers the only chance for cure. However, less than twenty percent of patients are considered operative candidates at the time of diagnosis. A common reason for being classified as unresectable is advanced loco-regional disease.
A review of the literature indicates that almost nine hundred patients with pancreatic cancer have received regional chemotherapy in the last 15 years. Phase I studies have shown regional administration of chemotherapy to be safe. The average reported response rate was approximately 26%. The average 1-year survival was 39%, with an average median survival of 9 months. Of the patients that experienced a radiographic response to therapy, 78 (78/277, 28%) patients underwent exploratory surgery following regional chemotherapy administration; thirty-two (41%) of those patients were amenable to pancreatectomy. None of the studies performed analyses to identify factors predicting response to regional chemotherapy.
Progressive surgical techniques combined with current neoadjuvant chemoradiotherapy strategies have already yielded emerging support for a multimodality approach to treatment of advanced pancreatic cancer.
Intravenous gemcitabine is the current standard treatment of pancreatic cancer. However, >90% of the drug is secreted unchanged affecting toxicity but not the cancer per se. Gemcitabine is converted inside the cell into its active drug form in a rate limiting reaction. We hypothesize that neoadjuvant regional chemotherapy with continuous infusion of gemcitabine will be well tolerated and may improve resectability rates in cases of locally advanced pancreatic cancer.

Design
This is a phase I study designed to evaluate the feasibility and toxicity of super-selective intra-arterial administration of gemcitabine in patients with locally advanced, unresectable pancreatic adenocarcinoma. Patients considered unresectable due to locally advanced pancreatic cancer will receive super-selective arterial infusion of gemcitabine over 24 hours via subcutaneous indwelling port. Three to six patients will be enrolled per dose cohort, with seven cohorts, plus an additional six patients at the maximum tolerated dose; accrual is expected to last 36 months. Secondary objectives will include the determination of progression free and overall survival, as well as the conversion rate from unresectable to potentially resectable pancreatic cancer.

Trial Registration
ClinicalTrials.gov ID: NCT01294358