30 research outputs found

    Anti-HIV Activity in Cervical-Vaginal Secretions from HIV-Positive and -Negative Women Correlate with Innate Antimicrobial Levels and IgG Antibodies

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    We investigated the impact of antimicrobials in cervicovaginal lavage (CVL) from HIV(+) and HIV(βˆ’) women on target cell infection with HIV. Since female reproductive tract (FRT) secretions contain a spectrum of antimicrobials, we hypothesized that CVL from healthy HIV(+) and (βˆ’) women inhibit HIV infection. indicated that each was present in CVL from HIV(+) and HIV(βˆ’) women. HBD2 and MIP3Ξ± correlated with anti-HIV activity as did anti-gp160 HIV IgG antibodies in CVL from HIV(+) women.These findings indicate that CVL from healthy HIV(+) and HIV(βˆ’) women contain innate and adaptive defense mechanisms that inhibit HIV infection. Our data suggest that innate endogenous antimicrobials and HIV-specific IgG in the FRT can act in concert to contribute toward the anti-HIV activity of the CVL and may play a role in inhibition of HIV transmission to women

    Anti-HIV Activity in Cervical-Vaginal Secretions from HIV-Positive and -Negative Women Correlate with Innate Antimicrobial Levels and IgG Antibodies

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    Background: We investigated the impact of antimicrobials in cervicovaginal lavage (CVL) from HIV(+) and HIV(2) women on target cell infection with HIV. Since female reproductive tract (FRT) secretions contain a spectrum of antimicrobials, we hypothesized that CVL from healthy HIV(+) and (2) women inhibit HIV infection. Methodology/Principal Findings: CVL from 32 HIV(+) healthy women with high CD4 counts and 15 healthy HIV(2) women were collected by gently washing the cervicovaginal area with 10 ml of sterile normal saline. Following centrifugation, anti- HIV activity in CVL was determined by incubating CVL with HIV prior to addition to TZM-bl cells. Antimicrobials and anti- gp160 HIV IgG antibodies were measured by ELISA. When CXCR4 and CCR5 tropic HIV-1 were incubated with CVL from HIV(+) women prior to addition to TZM-bl cells, anti-HIV activity in CVL ranged from none to 100% inhibition depending on the viral strains used. CVL from HIV(2) controls showed comparable anti-HIV activity. Analysis of CH077.c (clone of an R5- tropic, mucosally-transmitted founder virus) viral inhibition by CVL was comparable to laboratory strains. Measurement of CVL for antimicrobials HBD2, trappin-2/elafin, SLPI and MIP3a indicated that each was present in CVL from HIV(+) and HIV(2) women. HBD2 and MIP3a correlated with anti-HIV activity as did anti-gp160 HIV IgG antibodies in CVL from HIV(+) women. Conclusions/Significance: These findings indicate that CVL from healthy HIV(+) and HIV(2) women contain innate and adaptive defense mechanisms that inhibit HIV infection. Our data suggest that innate endogenous antimicrobials and HIV- specific IgG in the FRT can act in concert to contribute toward the anti-HIV activity of the CVL and may play a role in inhibition of HIV transmission to women

    The transcriptome and proteome of the diatom Thalassiosira pseudonana reveal a diverse phosphorus stress response

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    Β© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS One 7 (2012): e33768, doi:10.1371/journal.pone.0033768.Phosphorus (P) is a critical driver of phytoplankton growth and ecosystem function in the ocean. Diatoms are an abundant class of marine phytoplankton that are responsible for significant amounts of primary production. With the control they exert on the oceanic carbon cycle, there have been a number of studies focused on how diatoms respond to limiting macro and micronutrients such as iron and nitrogen. However, diatom physiological responses to P deficiency are poorly understood. Here, we couple deep sequencing of transcript tags and quantitative proteomics to analyze the diatom Thalassiosira pseudonana grown under P-replete and P-deficient conditions. A total of 318 transcripts were differentially regulated with a false discovery rate of <0.05, and a total of 136 proteins were differentially abundant (p<0.05). Significant changes in the abundance of transcripts and proteins were observed and coordinated for multiple biochemical pathways, including glycolysis and translation. Patterns in transcript and protein abundance were also linked to physiological changes in cellular P distributions, and enzyme activities. These data demonstrate that diatom P deficiency results in changes in cellular P allocation through polyphosphate production, increased P transport, a switch to utilization of dissolved organic P through increased production of metalloenzymes, and a remodeling of the cell surface through production of sulfolipids. Together, these findings reveal that T. pseudonana has evolved a sophisticated response to P deficiency involving multiple biochemical strategies that are likely critical to its ability to respond to variations in environmental P availability.This research was supported by the National Science Foundation (NSF) Environmental Genomics and NSF Biological Oceanography Program through grant OCE-0723667 to Dr. Dyhrman, Dr. Jenkins, Dr. Saito, and Dr. Rynearson, the NSF Chemical Oceanography Program through grant OCE-0549794 to Dr. Dyhrman and OCE-0526800 to Dr. Jenkins, the G. B. Moore Foundation and OCE-0752291 to Dr. Saito, NSF-EPSCoR (NSF-0554548 & NSF-1004057) to the University of Rhode Island, the Center for Microbial Oceanography: Research and Education, and the Joint Genome Institute/DOE Community Sequencing Program (CSP795793) to Dr. Jenkins, Dr. Dyhrman, Dr. Rynearson and Dr. Saito

    Empirical bayes analysis of sequencing-based transcriptional profiling without replicates

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    Background: Recent technological advancements have made high throughput sequencing an increasingly popular approach for transcriptome analysis. Advantages of sequencing-based transcriptional profiling over microarrays have been reported, including lower technical variability. However, advances in technology do not remove biological variation between replicates and this variation is often neglected in many analyses. Results: We propose an empirical Bayes method, titled Analysis of Sequence Counts (ASC), to detect differential expression based on sequencing technology. ASC borrows information across sequences to establish prior distribution of sample variation, so that biological variation can be accounted for even when replicates are not available. Compared to current approaches that simply tests for equality of proportions in two samples, ASC is less biased towards highly expressed sequences and can identify more genes with a greater log fold change at lower overall abundance. Conclusions: ASC unifies the biological and statistical significance of differential expression by estimating the posterior mean of log fold change and estimating false discovery rates based on the posterior mean. The implementation in R is available at http://www.stat.brown.edu/Zwu/research.aspx

    Kinetics of Host Cell Recruitment During Dissemination of Diffuse Malignant Peritoneal Mesothelioma

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    Diffuse malignant mesothelioma is an aggressive tumor which displays a median survival of 11.2Β months and a 5-year survival of less than 5% emphasizing the need for more effective treatments. This study uses an orthotopic model of malignant mesothelioma established in syngeneic, immunocompetent C57Bl/6 mice which produce malignant ascites and solid tumors that accurately replicate the histopathology of the human disease. Host stromal and immune cell accumulation within malignant ascites and solid tumors was determined using immunofluorescent labeling with confocal microscopy and fluorescence-activated cell sorting. An expression profile of cytokines and chemokines was produced using quantitative real-time PCR arrays. Tumor spheroids and solid tumors show progressive growth and infiltration with host stromal and immune cells including macrophages, endothelial cells, CD4+ and CD8+ lymphocytes, and a novel cell type, myeloid derived suppressor cells (MDSCs). The kinetics of host cell accumulation and inflammatory mediator expression within the tumor ascites divides tumor progression into two distinct phases. The first phase is characterized by progressive macrophage and T lymphocyte recruitment, with a cytokine profile consistent with regulatory T lymphocytes differentiation and suppression of T cell function. The second phase is characterized by decreased expression of macrophage chemotactic and T-cell regulating factors, an increase in MDSCs, and increased expression of several cytokines which stimulate differentiation of MDSCs. This cellular and expression profile suggests a mechanism by which host immune cells promote diffuse malignant mesothelioma progression

    Characterization of colon cancer cells: a functional approach characterizing CD133 as a potential stem cell marker

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    <p>Abstract</p> <p>Background</p> <p>Isolation and characterization of tumourigenic colon cancer initiating cells may help to develop novel diagnostic and therapeutic procedures.</p> <p>Methods</p> <p>We characterized a panel of fourteen human colon carcinoma cell lines and their corresponding xenografts for the surface expression of potential stem cell markers CD133, CD24, CD44, CDCP1 and CXCR4. In five cell lines and nine xenografts, mRNA expression of these markers was determined. Tumour growth behaviour of CD133+, CD133- and unsorted SW620 cells was evaluated <it>in vivo</it>.</p> <p>Results</p> <p>All five putative stem cell markers showed distinct expression patterns in the tumours examined. Two patient-derived cell lines highly expressed CD133 (> 85% of positive cells) and three other cell lines had an expression level of about 50% whereas in long-term culture based models CD133 expression ranged only from 0 to 20%. In 8/14 cell lines, more than 80% of the cells were positive for CD24 and 11/14 were over 70% positive for CD44. 10/14 cell lines expressed CDCP1 on β‰₯ 83% of cells. CXCR4 expression was determined solely on 94 L and SW480.</p> <p>Analyses of the corresponding xenografts revealed a significant reduction of cell numbers expressing the investigated surface markers and showed single cell fractions expressing up to three markers simultaneously.</p> <p>Statistical analysis revealed that the CXCR4 mRNA level correlates negatively with the protein expression of CD133, CD44, CD24 and CDCP1 in cell lines and xenografts.</p> <p>A lower differentiation grade of donor material correlated with a higher CDCP1 mRNA expression level in the respective tumour model.</p> <p><it>In vivo </it>growth behaviour studies of SW620 revealed significantly higher take rates and shorter doubling times in the tumour growth of CD133 positive subclones in comparison to the unsorted cell line or CD133 negative subclones.</p> <p>Conclusions</p> <p>Our data revealed correlations in the expression of surface markers CD44 and CD24 as well as CD44 and CDCP1 and strongly suggest that CD133 is a stem cell marker within our colon carcinoma panel. Further studies will elucidate its role as a potential therapeutic target.</p

    Transcriptional Activation of OsDERF1 in OsERF3 and OsAP2-39 Negatively Modulates Ethylene Synthesis and Drought Tolerance in Rice

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    The phytohormone ethylene is a key signaling molecule that regulates a variety of developmental processes and stress responses in plants. Transcriptional modulation is a pivotal process controlling ethylene synthesis, which further triggers the expression of stress-related genes and plant adaptation to stresses; however, it is unclear how this process is transcriptionally modulated in rice. In the present research, we report the transcriptional regulation of a novel rice ethylene response factor (ERF) in ethylene synthesis and drought tolerance. Through analysis of transcriptional data, one of the drought-responsive ERF genes, OsDERF1, was identified for its activation in response to drought, ethylene and abscisic acid. Transgenic plants overexpressing OsDERF1 (OE) led to reduced tolerance to drought stress in rice at seedling stage, while knockdown of OsDERF1 (RI) expression conferred enhanced tolerance at seedling and tillering stages. This regulation was supported by negative modulation in osmotic adjustment response. To elucidate the molecular basis of drought tolerance, we identified the target genes of OsDERF1 using the Affymetrix GeneChip, including the activation of cluster stress-related negative regulators such as ERF repressors. Biochemical and molecular approaches showed that OsDERF1 at least directly interacted with the GCC box in the promoters of ERF repressors OsERF3 and OsAP2-39. Further investigations showed that OE seedlings had reduced expression (while RI lines showed enhanced expression) of ethylene synthesis genes, thereby resulting in changes in ethylene production. Moreover, overexpression of OsERF3/OsAP2-39 suppressed ethylene synthesis. In addition, application of ACC recovered the drought-sensitive phenotype in the lines overexpressing OsERF3, showing that ethylene production contributed to drought response in rice. Thus our data reveal that a novel ERF transcriptional cascade modulates drought response through controlling the ethylene synthesis, deepening our understanding of the regulation of ERF proteins in ethylene related drought response
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