3,764 research outputs found

    Next-Generation mRNA Sequencing Reveals Pyroptosis-Induced CD4+ T Cell Death in Early Simian Immunodeficiency Virus-Infected Lymphoid Tissues

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    Lymphoid tissues (LTs) are the principal sites where human immunodeficiency virus type 1 (HIV-1) replicates and virus-host interactions take place, resulting in immunopathology in the form of inflammation, immune activation, and CD4+ T cell death. The HIV-1 pathogenesis in LTs has been extensively studied; however, our understanding of the virus-host interactions in the very early stages of infection remains incomplete. We investigated virus-host interactions in the rectal draining lymph nodes (dLNs) of rhesus macaques at different times after intrarectal inoculation (days postinoculation [dpi]) with simian immunodeficiency virus (SIV). At 3 dpi, 103 differentially expressed genes (DEGs) were detected using next-generation mRNA sequencing (RNA-seq). At 6 and 10 dpi, concomitant with increased SIV replication, 366 and 1,350 DEGs were detected, respectively, including upregulation of genes encoding proteins that play a role in innate antiviral immune responses, inflammation, and immune activation. Notably, genes (IFI16, caspase-1, and interleukin 1ÎČ [IL-1ÎČ]) in the canonical pyroptosis pathway were significantly upregulated in expression. We further validated increased pyroptosis using flow cytometry and found that the number of CD4+ T cells expressing activated caspase-1 protein, the hallmark of ongoing pyroptosis, were significantly increased, which is correlated with decreased CD4+ T cells in dLNs. Our results demonstrated that pyroptosis contributes to the CD4+ T cell death in vivo in early SIV infection, which suggests that pyroptosis may play a pivotal role in the pathogenesis of SIV, and by extension, that of HIV-1, since pyroptosis not only induces CD4+ T cell death but also amplifies inflammation and immune activation. Thus, blocking CD4+ T cell pyroptosis could be a complementary treatment to antiretroviral therapy

    The mucosal expression pattern of interferon-Δ in rhesus macaques

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    Type I IFNs play an important role in innate and adaptive immunity against viral infections. A novel type I IFN, namely IFN-Δ, which can protect against vaginal transmission of HSV2 and Chlamydia muridarum bacterial infection, has been described in mice and humans. Nevertheless, the principle cell type and the expression pattern of IFN-Δ in tissues remain uncertain. In addition, the expression of IFN-Δ in Indian rhesus macaques (Macaca mulatta) has not been reported. Here, we analyzed IFN-Δ expression in multiple mucosal sites of uninfected or SIV-infected Indian rhesus macaques using IHCS. We report for the first time the detection of IFN-Δ expression in situ in the lung, foreskin, vaginal, cervical, and small and large intestinal mucosae of rhesus macaques. We found that the expression of IFN-Δ was exclusive to the epithelial cells in all of the aforementioned mucosal tissues. Furthermore, the macaque IFN-Δ sequence in this study revealed that macaque IFN-Δ is highly conserved among human and other nonhuman primates. Lastly, SIV rectal infection did not significantly alter the expression of IFN-Δ in rectal mucosae. Together, these findings indicate that IFN-Δ may function as the first line of defense against the invasion of mucosal pathogens. Further studies should be conducted to examine IFN-Δ protection against gastrointestinal as well as respiratory infections. Includes supplementary material

    Next-Generation mRNA Sequencing Reveals Pyroptosis-Induced CD4+ T Cell Death in Early Simian Immunodeficiency Virus-Infected Lymphoid Tissues

    Get PDF
    Lymphoid tissues (LTs) are the principal sites where human immunodeficiency virus type 1 (HIV-1) replicates and virus-host interactions take place, resulting in immunopathology in the form of inflammation, immune activation, and CD4+ T cell death. The HIV-1 pathogenesis in LTs has been extensively studied; however, our understanding of the virus-host interactions in the very early stages of infection remains incomplete. We investigated virus-host interactions in the rectal draining lymph nodes (dLNs) of rhesus macaques at different times after intrarectal inoculation (days postinoculation [dpi]) with simian immunodeficiency virus (SIV). At 3 dpi, 103 differentially expressed genes (DEGs) were detected using next-generation mRNA sequencing (RNA-seq). At 6 and 10 dpi, concomitant with increased SIV replication, 366 and 1,350 DEGs were detected, respectively, including upregulation of genes encoding proteins that play a role in innate antiviral immune responses, inflammation, and immune activation. Notably, genes (IFI16, caspase-1, and interleukin 1ÎČ [IL-1ÎČ]) in the canonical pyroptosis pathway were significantly upregulated in expression. We further validated increased pyroptosis using flow cytometry and found that the number of CD4+ T cells expressing activated caspase-1 protein, the hallmark of ongoing pyroptosis, were significantly increased, which is correlated with decreased CD4+ T cells in dLNs. Our results demonstrated that pyroptosis contributes to the CD4+ T cell death in vivo in early SIV infection, which suggests that pyroptosis may play a pivotal role in the pathogenesis of SIV, and by extension, that of HIV-1, since pyroptosis not only induces CD4+ T cell death but also amplifies inflammation and immune activation. Thus, blocking CD4+ T cell pyroptosis could be a complementary treatment to antiretroviral therapy

    Validation of nonlinear PCA

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    Linear principal component analysis (PCA) can be extended to a nonlinear PCA by using artificial neural networks. But the benefit of curved components requires a careful control of the model complexity. Moreover, standard techniques for model selection, including cross-validation and more generally the use of an independent test set, fail when applied to nonlinear PCA because of its inherent unsupervised characteristics. This paper presents a new approach for validating the complexity of nonlinear PCA models by using the error in missing data estimation as a criterion for model selection. It is motivated by the idea that only the model of optimal complexity is able to predict missing values with the highest accuracy. While standard test set validation usually favours over-fitted nonlinear PCA models, the proposed model validation approach correctly selects the optimal model complexity.Comment: 12 pages, 5 figure

    Photo-Induced Click Chemistry for DNA Surface Structuring by Direct Laser Writing.

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    Oligonucleotides containing photo-caged dienes were prepared and shown to react quantitatively in a light-induced Diels-Alder cycloaddition with functional maleimides in aqueous solution within minutes. Due to its high yield and fast rate, the reaction was exploited for DNA surface patterning with sub-micrometer resolution employing direct laser writing (DLW). Functional DNA arrays were written by direct laser writing (DLW) in variable patterns, which were further encoded with fluorophores and proteins through DNA directed immobilization. This mild and efficient light-driven platform technology holds promise for the fabrication of complex bioarrays with sub-micron resolution

    Comparative analysis of pathogenic and nonpathogenic Fusarium oxysporum populations associated with banana on a farm in Minas Gerais, Brazil

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    Fusarium wilt is one of the most devastating diseases on banana. The causal agent, Fusarium oxysporum f. sp. cubense (Foc) is genetically diverse and its origin and virulence are poorly understood. In this study, pathogenic Foc isolates and nonpathogenic F.oxysporum isolates from Minas Gerais in Brazil were compared using EF-1 and IGS sequences. This allowed the examination of the origin and evolutionary potential of Foc in a country outside the region of origin of the banana plant. Two different sequence types were found among Foc isolates. One appeared to be of local origin because it was identical to the sequence type of the largest group of nonpathogenic isolates. To explore if the local' Foc isolates had acquired pathogenicity either independently through coevolution with the host, or through horizontal gene transfer (HGT) of pathogenicity genes from other, probably introduced, Foc isolates, the presence and sequence of putative SIX effector genes were analysed. Homologues of SIX1, SIX3 and SIX8 were found. SIX1 sequences were identical and exclusively found in all pathogenic isolates, while variable ratios of sequences of multicopy gene SIX8 were found among nonpathogenic and different pathogenic isolates. This observation supports the HGT hypothesis. Horizontal transfer of genes between isolates of F.oxysporum has important implications for the development of reliable diagnostic tools and effective control measures. Full genome sequencing is required to confirm HGT and to further unravel the virulence mechanisms of forma specialis cubense

    Comparison of the efficacy and safety of azilsartan with that of candesartan cilexetil in Japanese patients with grade I–II essential hypertension: a randomized, double-blind clinical study

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    Azilsartan is a novel angiotensin receptor blocker being developed for hypertension treatment. This 16-week, multicenter, randomized, double-blind study compared the efficacy and safety of azilsartan (20–40 mg once daily by forced titration) and its ability to provide 24-h blood pressure (BP) control, with that of candesartan cilexetil (candesartan; 8–12 mg once daily by forced titration) in 622 Japanese patients with grade I–II essential hypertension. Efficacy was evaluated by clinic-measured sitting BP, and by ambulatory BP monitoring (ABPM) at week 14. Participants (mean age: 57 years, 61% males) had a mean baseline sitting BP of 159.8/100.4 mm Hg. The mean change from baseline in sitting diastolic BP at week 16 (primary endpoint) was −12.4 mm Hg in the azilsartan group and −9.8 mm Hg in the candesartan group, demonstrating a statistically significant greater reduction with azilsartan vs. candesartan (difference: −2.6 mm Hg, 95% confidence interval (CI): −4.08 to −1.22 mm Hg, P=0.0003). The week 16 (secondary endpoint) mean change from baseline in sitting systolic BP was −21.8 mm Hg and −17.5 mm Hg, respectively, a significant decrease with azilsartan vs. candesartan (difference: −4.4 mm Hg, 95% CI: −6.53 to −2.20 mm Hg, P<0.0001). On ABPM, the week 14 mean changes from baseline in diastolic and systolic BP were also significantly greater with azilsartan over a 24-h period, and during the daytime, night-time and early morning. Safety and tolerability were similar among the two groups. These data demonstrate that once-daily azilsartan provides a more potent 24-h sustained antihypertensive effect than that of candesartan but with equivalent safety
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