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Virology
Integrative analysis identifies targetable CREB1/FoxA1 transcriptional co-regulation as a predictor of prostate cancer recurrence
Apr 18, 2017   Nucleic Acids Research
Sunkel B, Wu D, Chen Z, Wang CM, Liu X,   . . . . . .   , Clinton SK, Jin VX, Chen CL, Huang TH, Wang Q
Epstein-Barr virus ensures B cell survival by uniquely modulating apoptosis at early and late times after infection
Apr 20, 2017   ELife
Price AM, Dai J, Bazot Q, Patel L, Nikitin PA, Djavadian R, Winter PS, Salinas CA, Barry AP, Wood KC, Johannsen EC, Letai A, Allday MJ, Luftig MA
Epstein-Barr virus ensures B cell survival by uniquely modulating apoptosis at early and late times after infection
Apr 20, 2017
ELife
Latent Epstein-Barr virus (EBV) infection is causally linked to several human cancers. EBV expresses viral oncogenes that promote cell growth and inhibit the apoptotic response to uncontrolled proliferation. The EBV oncoprotein LMP1 constitutively activates NFB and is critical for survival of EBV-immortalized B cells. However, during early infection EBV induces rapid B cell proliferation with low levels of LMP1 and little apoptosis. Therefore, we sought to define the mechanism of survival in the absence of LMP1/NFB early after infection. We used BH3 profiling to query mitochondrial regulation of apoptosis and defined a transition from uninfected B cells (BCL-2) to early-infected (MCL-1/BCL-2) and immortalized cells (BFL-1). This dynamic change in B cell survival mechanisms is unique to virus-infected cells and relies on regulation of MCL-1 mitochondrial localization and BFL-1 transcription by the viral EBNA3A protein. This study defines a new role for EBNA3A in the suppression of apoptosis with implications for EBV lymphomagenesis.
Structure of the S1 subunit C-terminal domain from bat-derived coronavirus HKU5 spike protein
Apr 22, 2017   Virology
Han X, Qi J, Song H, Wang Q, Zhang Y, Wu Y, Lu G, Yuen KY, Shi Y, Gao GF
Structure of the S1 subunit C-terminal domain from bat-derived coronavirus HKU5 spike protein
Apr 22, 2017
Virology
Accumulating evidence indicates that MERS-CoV originated from bat coronaviruses (BatCoVs). Previously, we demonstrated that both MERS-CoV and BatCoV HKU4 use CD26 as a receptor, but how the BatCoVs evolved to bind CD26 is an intriguing question. Here, we solved the crystal structure of the S1 subunit C-terminal domain of HKU5 (HKU5-CTD), another BatCoV that is phylogenetically related to MERS-CoV but cannot bind to CD26. We observed that the conserved core subdomain and those of other betacoronaviruses (betaCoVs) have a similar topology of the external subdomain, indicating the same ancestor of lineage C betaCoVs. However, two deletions in two respective loops located in HKU5-CTD result in conformational variations in CD26-binding interface and are responsible for the non-binding of HKU5-CTD to CD26. Combined with sequence variation in the HKU5-CTD receptor binding interface, we propose the necessity for surveilling the mutation in BatCoV HKU5 spike protein in case of bat-to-human interspecies transmission. Copyright © 2017 Elsevier Inc. All rights reserved.
Effects of naturally occurring charged mutations on the structure, stability, and binding of the Pin1 WW domain
Apr 22, 2017   Biochemical And Biophysical Research Communications
Qiao X, Liu Y, Luo L, Chen L, Zhao C, Ai X
Effects of naturally occurring charged mutations on the structure, stability, and binding of the Pin1 WW domain
Apr 22, 2017
Biochemical And Biophysical Research Communications
Pin1 is a peptidyl-prolyl cis-trans isomerase, whose WW domain specifically recognizes the pSer/Thr-Pro motif. Pin1 is involved in multiple phosphorylation events that regulate the activities of various substrates, and Pin1 deregulation has been reported in various diseases, including cancer and Alzheimer's disease. The WW domain of Pin1 has been used as a small model protein to investigate the folding mechanisms of the β-sheet structure by studying the effect of mutations or its naturally occurring variants. However, only a few studies have investigated the structure and binding of Pin1 WW mutants. In the present work, two naturally occurring Pin1 WW variants, namely, G20D and S16R, derived from the cynomolgus monkey and African green monkey, respectively, were selected to investigate the influence of charge mutation on the structure, stability, and binding properties of the Pin1 WW domain. Analysis using a combination of nuclear magnetic resonance (NMR) and chemical shift-based calculations revealed that the G20D and S16R mutants had high structural similarity to the wild-type Pin1 WW domain. However, the presence of a charge mutation significantly decreased the stability of the Pin1 WW domain. Both the wild-type and G20D forms of the Pin1 WW domain utilized a three-site mode to bind to a phosphorylated Tau peptide, pT231, whereas the S16R mutant binds to the pT231 peptide either in a non-specific manner or through a totally different binding mechanism. Correspondingly, the wild-type and two mutant Pin1 WW domains showed different binding affinities to the Tau phosphopeptide. Considering that the WW domain participates in the catalytic activity of the Pin1 isomerase, our study represents a novel approach for studying Pin1 function through the analysis of its naturally occurring mutants. Copyright © 2017 Elsevier Inc. All rights reserved.
Hepatitis C virus NS4B protein induces epithelial-mesenchymal transition by upregulation of Snail
Apr 22, 2017   Virology Journal
Hu B, Xie S, Hu Y, Chen W, Chen X, Zheng Y, Wu X
Hepatitis C virus NS4B protein induces epithelial-mesenchymal transition by upregulation of Snail
Apr 22, 2017
Virology Journal
Chronic hepatitis C virus (HCV) infection is an important cause of hepatocellular carcinoma (HCC). Epithelial to mesenchymal transition (EMT) is a key process associated with tumor metastasis and poor prognosis. HCV infection, HCV core and NS5A protein could induce EMT process, but the role of NS4B on EMT remains poorly understood. We overexpressed HCV NS4B protein in HepG2 cells or Huh7.5.1 cells infected by HCVcc, the E-cadherin expression, N-cadherin expression and the EMT-associated transcriptional factor Snail were determined. The migration and invasion capabilities of the transfected cells were evaluated using wound-healing assay. Additionally, we used Snail siRNA interference to confirm the relation of HCV NS4B and Snail on EMT promotion. HCV NS4B increased the expression of EMT related markers and promoted cell migration and invasion. Snail knock-down almost completely eliminated the function of NS4B protein in EMT changes and reversed cell migration capacity to lower level. HCV NS4B protein could reduce the expression of Scribble and Hippo signal pathway were subsequently inactivated, resulting in the activation of PI3K/AKT pathway, which may be the reason for the up-regulation of Snail. This study demonstrates that HCV NS4B protein induces EMT progression via the upregulation of Snail in HCC, which may be a novel underlying mechanism for HCV-associated HCC development, invasion and metastasis.
Zika virus infection of adult and fetal STAT2 knock-out hamsters
Apr 21, 2017   Virology
Siddharthan V, Van Wettere AJ, Li R, Miao J, Wang Z, Morrey JD, Julander JG
Zika virus infection of adult and fetal STAT2 knock-out hamsters
Apr 21, 2017
Virology
Zika virus (ZIKV) infection was investigated in adult and fetal STAT2 knock-out (KO) hamsters. Subcutaneous injection of ZIKV of adults resulted in morbidity, mortality, and infection of the uterus, placenta, brain, spinal cord, and testicles, thus providing an opportunity to evaluate congenital ZIKV infection in a second rodent species besides mice. ZIKV-infected cells with morphologies of Sertoli cells and spermatogonia were observed in the testes, which may have implications for sexual transmission and male sterility. Neonates exposed as fetuses to ZIKV at 8 days post-coitus were not smaller than controls. Nevertheless, infectious virus and ZIKV RNA was detected in some, but not all, placentas and fetal brains of KO hamsters. STAT2 KO hamsters may be useful for addressing sexual transmission, pathogenesis, routes of fetal infection, and neurological disease outcomes, and may also be used in antiviral or vaccine studies to identify intervention strategies. Copyright © 2017. Published by Elsevier Inc.
Kaposi Sarcoma Herpesvirus (KSHV) Latency-Associated Nuclear Antigen (LANA) recruits components of the MRN (Mre11-Rad50-NBS1) repair complex to modulate an innate immune signaling pathway and viral latency
Apr 21, 2017   PLoS Pathogens
Mariggiò G, Koch S, Zhang G, Weidner-Glunde M, Rückert J, Kati S, Santag S, Schulz TF
Kaposi Sarcoma Herpesvirus (KSHV) Latency-Associated Nuclear Antigen (LANA) recruits components of the MRN (Mre11-Rad50-NBS1) repair complex to modulate an innate immune signaling pathway and viral latency
Apr 21, 2017
PLoS Pathogens
Kaposi Sarcoma Herpesvirus (KSHV), a γ2-herpesvirus and class 1 carcinogen, is responsible for at least three human malignancies: Kaposi Sarcoma (KS), Primary Effusion Lymphoma (PEL) and Multicentric Castleman's Disease (MCD). Its major nuclear latency protein, LANA, is indispensable for the maintenance and replication of latent viral DNA in infected cells. Although LANA is mainly a nuclear protein, cytoplasmic isoforms of LANA exist and can act as antagonists of the cytoplasmic DNA sensor, cGAS. Here, we show that cytosolic LANA also recruits members of the MRN (Mre11-Rad50-NBS1) repair complex in the cytosol and thereby inhibits their recently reported role in the sensing of cytoplasmic DNA and activation of the NF-κB pathway. Inhibition of NF-κB activation by cytoplasmic LANA is accompanied by increased lytic replication in KSHV-infected cells, suggesting that MRN-dependent NF-κB activation contributes to KSHV latency. Cytoplasmic LANA may therefore support the activation of KSHV lytic replication in part by counteracting the activation of NF-κB in response to cytoplasmic DNA. This would complement the recently described role of cytoplasmic LANA in blocking an interferon response triggered by cGAS and thereby promoting lytic reactivation. Our findings highlight a second point at which cytoplasmic LANA interferes with the innate immune response, as well as the importance of the recently discovered role of cytoplasmic MRN complex members as innate sensors of cytoplasmic DNA for the control of KSHV replication.
Involvement of methylated HBHA expressed from Mycobacterium smegmatis in an IFN-γ release assay to aid discrimination between latent infection and active tuberculosis in BCG-vaccinated populations
Apr 21, 2017   European Journal Of Clinical Microbiology & Infectious Diseases : Official Publication Of The European Society Of Clinical Microbiology
Wen HL, Li CL, Li G, Lu YH, Li HC, Li T, Zhao HM, Wu K, Lowrie DB, Lv JX, Lu SH, Fan XY
Involvement of methylated HBHA expressed from Mycobacterium smegmatis in an IFN-γ release assay to aid discrimination between latent infection and active tuberculosis in BCG-vaccinated populations
Apr 21, 2017
European Journal Of Clinical Microbiology & Infectious Diseases : Official Publication Of The European Society Of Clinical Microbiology
IFN-γ release assays (IGRAs) based on region of difference 1 (RD1) antigens have improved diagnosis of Mycobacterium tuberculosis (M. tb) infection. However, IGRAs with these antigens cannot discriminate between active tuberculosis (ATB) and latent tuberculosis infection (LTBI). M. tb heparin-binding-hemagglutinin (HBHA) induces relatively high IFN-γ responses in LTBI individuals and low responses in ATB patients, but purification of the native methylated HBHA from cultures of M. tb for immunological tests is complex and time-consuming. To overcome these cumbersome procedures, we constructed a recombinant Mycobacterium smegmatis strain that over-expressed HBHA under control of a strong furA promoter. The methylated activity of purified protein was verified by hybridization with anti-methylated Lys antibody, and the methylated HBHA (mHBHA) was further evaluated for antigen-specific IFN-γ responses in BCG-vaccinated Chinese population. A total of 138 individuals including 86 active TB (ATB) patients, 15 latent TB infection (LTBI) cases, and 37 healthy controls (HC) were tested by using an IFN-γ enzyme-linked immunospot (ELISPOT) assay. The results showed that T-cell responses against mHBHA were always lower in ATB patients than in LTBI individuals, regardless of the site of infection or the results of bacteriological tests. This allowed for a good discrimination between these two groups of M. tb-infected individuals, even in the BCG-vaccinated and high TB-incidence setting that is China. Additionally, combination of mHBHA and RD1 antigens in an IFN-γ release assay enhanced diagnostic efficacy for active TB cases. Taken together, inclusion of the immune response to mHBHA can discriminate healthy LTBI cases from ATB patients.
Transcriptomic analysis reveals a previously unknown role for CD8+ T-cells in rVSV-EBOV mediated protection
Apr 21, 2017   Scientific Reports
Menicucci AR, Sureshchandra S, Marzi A, Feldmann H, Messaoudi I
Transcriptomic analysis reveals a previously unknown role for CD8+ T-cells in rVSV-EBOV mediated protection
Apr 21, 2017
Scientific Reports
Ebola virus (EBOV) poses a significant threat to human health as highlighted by the recent epidemic in West Africa. Data from animal studies and a ring vaccination clinical trial conducted in Guinea during the recent epidemic demonstrated that a recombinant VSV where G protein is replaced with EBOV GP (rVSV-EBOV) is safe and highly efficacious. We previously established that antibodies are essential for rVSV-EBOV mediated protection against EBOV; however, the mechanisms by which this vaccine induces a humoral response and the role of T-cells in rVSV-EBOV mediated protection remain poorly understood. Since this is the only vaccine platform that has completed Phase III clinical studies, it is imperative to gain a better understanding of its mechanisms of protection. Therefore, we performed a longitudinal gene expression analysis of samples collected from controls and T-cell-depleted macaques after rVSV-EBOV vaccination and EBOV challenge. We show that rVSV-EBOV vaccination induces gene expression changes consistent with anti-viral immunity and B-cell proliferation. We also report a previously unappreciated role for CD8+ T-cells in mediating rVSV-EBOV protection. Finally, limited viral transcription in surviving animals may boost protective responses after EBOV challenge by maintaining transcriptional changes. This study presents a novel approach in determining mechanisms of vaccine efficacy.
Pygopus2 inhibits the efficacy of paclitaxel-induced apoptosis and induces multidrug resistance in human glioma cells
Apr 21, 2017   Oncotarget
Zhou C, Cheng H, Qin W, Zhang Y, Xiong H, Yang J, Huang H, Wang Y, Chen XZ, Tang J
Pygopus2 inhibits the efficacy of paclitaxel-induced apoptosis and induces multidrug resistance in human glioma cells
Apr 21, 2017
Oncotarget
Anti-microtubule drugs, such as paclitaxel (PTX), are extensively used for the treatment of numerous cancers. However, growing evidence has shown that PTX resistance, either intrinsic or acquired, frequently occurs in patients and results in the failure of treatment, contributing to the high cancer mortality rate. Therefore, it is necessary to identify the genes or pathways involved in anti-microtubule drug resistance for future successful treatment of cancers. Pygopus2 (Pygo2), which contains a Zn-coordinated plant homeodomain (PHD) finger domain, is critical for β-catenin-dependent transcriptional switches in normal and malignant tissues and is over-expressed in various cancers, including human brain glioma. In this study, we report that over-expression of Pygo2 inhibited the efficacy of PTX and contributed to cell multidrug resistance in two different ways. First, over-expression of Pygo2 inhibited the PTX-induced phosphorylation of B-cell lymphoma 2 (Bcl-2), suppressing the proteolytic cleavage of procaspase-8/9 and further inhibiting the activation of caspase-3, which also inhibits the activation of the JNK/SAPK pathway, ultimately inhibiting cell apoptosis. Second, over-expression of Pygo2 facilitated the expression of P-glycoprotein, which acts as a drug efflux pump, by promoting the transcription of Multi-drug resistance 1 (MDR1) at the MDR1 promoter loci, resulting in acceleration of the efflux of PTX.
Molecular characterization, tissue tropism, and genetic variability of the novel Mupapillomavirus type HPV204 and phylogenetically related types HPV1 and HPV63
Apr 20, 2017   PloS One
Šterbenc A, Hošnjak L, Chouhy D, Bolatti EM, Oštrbenk A, Seme K, Kocjan BJ, Luzar B, Giri AA, Poljak M
Molecular characterization, tissue tropism, and genetic variability of the novel Mupapillomavirus type HPV204 and phylogenetically related types HPV1 and HPV63
Apr 20, 2017
PloS One
HPV204 is the only newly identified Mupapillomavirus (Mu-PV) type in more than a decade. To comprehensively characterize HPV204, we performed a detailed molecular analysis of the viral genome and evaluated its clinical relevance in comparison to the other Mu-PVs, HPV1 and HPV63. The 7,227-bp long genome of HPV204 exhibits typical genomic organization of Mu-PVs with eight open reading frames (ORFs) (E6, E7, E1, E2, E8, E4, L2, and L1). We developed three type-specific quantitative real-time PCRs and used them to test a representative collection (n = 1,006) of various HPV-associated benign and malignant neoplasms, as well as samples of clinically normal cutaneous, mucosal, and mucocutaneous origins. HPV204, HPV1, and HPV63 were detected in 1.1%, 2.7%, and 1.9% of samples tested, respectively, and were present in skin and mucosa, suggesting dual tissue tropism of all Mu-PVs. To evaluate the etiological role of Mu-PVs in the development of HPV-associated neoplasms, Mu-PV viral loads per single cell were estimated. HPV1 and HPV63 were present in high viral copy numbers in 3/43 and 1/43 cutaneous warts, respectively, and were identified as the most likely causative agents of these warts. HPV204 viral load was extremely low in a single HPV204-positive cutaneous wart (7.4 × 10-7 viral copies/cell). Hence, etiological association between HPV204 and the development of cutaneous warts could not be established. To the best of our knowledge, this is the first study to evaluate the genetic variability of Mu-PVs by sequencing complete LCR genomic regions of HPV204, HPV1, and HPV63. We detected several nucleotide substitutions and deletions within the LCR genomic regions of Mu-PVs and identified two genetic variants of HPV204 and HPV63 and five genetic variants of HPV1.
Withaferin-A kills cancer cells with and without telomerase: chemical, computational and experimental evidences
Apr 20, 2017   Cell Death & Disease
Yu Y, Katiyar SP, Sundar D, Kaul Z, Miyako E, Zhang Z, Kaul SC, Reddel RR, Wadhwa R
Withaferin-A kills cancer cells with and without telomerase: chemical, computational and experimental evidences
Apr 20, 2017
Cell Death & Disease
Maintenance of telomere length is the most consistent attribute of cancer cells. Tightly connected to their capacity to overcome replicative mortality, it is achieved either by activation of telomerase or an Alternative mechanism of Lengthening of Telomeres (ALT). Disruption of either of these mechanisms has been shown to induce DNA damage signalling leading to senescence or apoptosis. Telomerase inhibitors are considered as potential anticancer drugs but are ineffective for ALT cancers (~15% of all cancers). Withaferin-A (Wi-A), a major constituent of the medicinal plant, Withania somnifera (Ashwagandha), has been shown to exert anti-tumour activity. However, its effect on either telomerase or ALT mechanisms has not been investigated. Here, by using isogenic cancer cells with/without telomerase, we found that Wi-A caused stronger cytotoxicity to ALT cells. It was associated with inhibition of ALT-associated promyelocytic leukemia nuclear bodies, an established marker of ALT. Comparative analyses of telomerase positive and ALT cells revealed that Wi-A caused stronger telomere dysfunction and upregulation of DNA damage response in ALT cells. Molecular computational and experimental analyses revealed that Wi-A led to Myc-Mad mediated transcriptional suppression of NBS-1, an MRN complex protein that is an essential component of the ALT mechanism. The results suggest that Wi-A could be a new candidate drug for ALT cancers.
Chytrid fungus infection in zebrafish demonstrates that the pathogen can parasitize non-amphibian vertebrate hosts
Apr 20, 2017   Nature Communications
Liew N, Mazon Moya MJ, Wierzbicki CJ, Hollinshead M, Dillon MJ, Thornton CR, Ellison A, Cable J, Fisher MC, Mostowy S
Chytrid fungus infection in zebrafish demonstrates that the pathogen can parasitize non-amphibian vertebrate hosts
Apr 20, 2017
Nature Communications
Aquatic chytrid fungi threaten amphibian biodiversity worldwide owing to their ability to rapidly expand their geographical distributions and to infect a wide range of hosts. Combating this risk requires an understanding of chytrid host range to identify potential reservoirs of infection and to safeguard uninfected regions through enhanced biosecurity. Here we extend our knowledge on the host range of the chytrid Batrachochytrium dendrobatidis by demonstrating infection of a non-amphibian vertebrate host, the zebrafish. We observe dose-dependent mortality and show that chytrid can infect and proliferate on zebrafish tissue. We also show that infection phenotypes (fin erosion, cell apoptosis and muscle degeneration) are direct symptoms of infection. Successful infection is dependent on disrupting the zebrafish microbiome, highlighting that, as is widely found in amphibians, commensal bacteria confer protection against this pathogen. Collectively, our findings greatly expand the limited tool kit available to study pathogenesis and host response to chytrid infection.
Hepatic expression of oncogenes Bmi1 and Dkk1 is up-regulated in hepatitis B virus surface antigen-transgenic mice and can be induced by treatment with HBV particles or lipopolysaccharides in vitro
Apr 18, 2017   International Journal Of Cancer
Zhang R, Real CI, Liu C, Baba HA, Gerken G, Lu M, Broering R
Hepatic expression of oncogenes Bmi1 and Dkk1 is up-regulated in hepatitis B virus surface antigen-transgenic mice and can be induced by treatment with HBV particles or lipopolysaccharides in vitro
Apr 18, 2017
International Journal Of Cancer
Previous studies have shown that hepatocellular carcinoma (HCC) develops more frequently in hepatitis B virus surface antigen (HBsAg)-transgenic mice (Alb/HBs) than in wild-type (WT) mice. However, the mechanism of this HCC model has not been well documented. Toll-like receptor 4 (Tlr4) signaling probably links innate immunity and HCC progression. The current study was designed to investigate the role of innate immunity in hepatocarcinogenesis in Alb/HBs mice. Immunohistochemical analysis of liver specimens from Alb/HBs mice (16 per group) showed that the oncogenes Bmi1 (16/16, 100%) and Dkk1 (13/16, 81.25%) were highly expressed in Alb/HBs mice, whereas the other oncogenes evaluated were expressed in smaller percentages of mice (Afp, 9/16, 56.2%; Ctnnb1, 5/16, 31.3%; Epcam, 0/16; 0%). Comparable results were obtained by quantitative PCR analysis. Hepatic gene expression of Tlr2, Tlr4, Il6 and Tnf was additionally elevated in Alb/HBs mice. Stimulation of primary murine hepatocytes with cell culture-derived HBV particles or LPS increased the expression of oncogenes (Bmi1, Dkk1) and inflammatory factors (Tnf, Il6, Tlr4). Proliferation and colony formation of hepatoma cells were enhanced by treatment with HBV and LPS and were impaired by the suppression of Bmi1 and Dkk1 by small interfering RNAs. Ssubstantial induction of BMI1 and DKK1 was found in liver biopsy samples from patients with HBV-related HCC but not in HCC samples without HBV infection background. These findings suggest that innate immunity may link inflammation and tumor progression during chronic HBV infection, involving the oncogenes BMI1 and DKK1. This article is protected by copyright. All rights reserved. © 2017 UICC.
Disruption of MDA5 mediated innate immune responses by the 3C proteins of Coxsackievirus A16, Coxsackievirus A6, and Enterovirus D68
Apr 20, 2017   Journal Of Virology
Rui Y, Su J, Wang H, Chang J, Wang S, Zheng W, Cai Y, Wei W, Gordy JT, Markham R, Kong W, Zhang W, Yu XF
Disruption of MDA5 mediated innate immune responses by the 3C proteins of Coxsackievirus A16, Coxsackievirus A6, and Enterovirus D68
Apr 20, 2017
Journal Of Virology
Coxsackievirus A16 (CV-A16), A6 (CV-A6), and enterovirus D68 (EV-D68) belong to the Picornaviridae family and are major causes of hand, foot, and mouth disease (HFMD) and pediatric respiratory disease worldwide. The biological characteristics of these viruses, especially their interplay with the host innate immune system, have not been well investigated. In this study, we discovered that the 3Cpro proteins from CV-A16, CV-A6, and EV-D68 bind MDA5 and inhibit its interaction with MAVS. Consequently, MDA5-triggered type I IFN signaling in the RLR pathway was blocked by CV-A16, CV-A6, and EV-D68 3Cpro Furthermore, CV-A16, CV-A6, and EV-D68 3Cpro all cleave TAK1, resulting in inhibition of NF-κB activation, a host response also critical for toll-like receptor (TLR) mediated signaling. Thus, our data demonstrate that circulating HFMD-associated CV-A16 and CV-A6, as well as severe respiratory disease-associated EV-D68, have developed novel mechanisms to subvert host innate immune responses by targeting key factors in the RLR and TLR pathways. Blocking the ability of 3Cpro from diverse enteroviruses and coxsackieviruses to interfere with type I IFN induction should restore IFN anti-viral function, offering a potential novel anti-viral strategy.IMPORTANCE CV-A16, CV-A6, and EV-D68 are emerging pathogens associated with hand, foot, and mouth disease and pediatric respiratory disease worldwide. The pathogenic mechanisms of these viruses are largely unknown. Here we demonstrate that the CV-A16, CV-A6, and EV-D68 3Cpro protease blocks MDA5-triggered type I IFN induction. 3Cpro of these viruses binds MDA5 and inhibits its interaction with MAVS. In addition, CV-A16, CV-A6, and EV-D68 3Cpro cleaves TAK1 to inhibit the NF-κB response. Thus, our data demonstrate that circulating HFMD-associated CV-A16 and CV-A6, as well as severe respiratory disease-associated EV-D68, have developed a mechanism to subvert host innate immune responses by simultaneously targeting key factors in the RLR and TLR pathways. These findings indicate the potential merit of targeting CV-A16, CV-A6, and EV-D68 3Cpro as an anti-viral strategy. Copyright © 2017 American Society for Microbiology.
Subtype-Specific Differences in Gag-Protease-Driven Replication Capacity are Consistent with Inter-Subtype Differences in HIV-1 Disease Progression
Apr 20, 2017   Journal Of Virology
Kiguoya MW, Mann JK, Chopera D, Gounder K, Lee GQ, Hunt PW, Martin JN, Ball TB, Kimani J, Brumme ZL, Brockman MA, Ndung'u T
Subtype-Specific Differences in Gag-Protease-Driven Replication Capacity are Consistent with Inter-Subtype Differences in HIV-1 Disease Progression
Apr 20, 2017
Journal Of Virology
There are marked differences in the spread and prevalence of HIV-1 subtypes worldwide, and differences in clinical progression have been reported. However, the biological reasons underlying these differences are unknown. Gag-protease is essential for HIV-1 replication and Gag-protease-driven replication capacity has previously been correlated with disease progression. We show that Gag-protease replication capacity correlates significantly with that of whole isolates (r=0.51; p=0.04), indicating that Gag-protease is a significant contributor to viral replication capacity. Furthermore, we investigated subtype-specific differences in Gag-protease-driven replication capacity using large well-characterised cohorts in Africa and the Americas. Patient-derived Gag-protease sequences were inserted into an HIV-1 NL4-3 backbone and the replication capacities of the resulting recombinant viruses were measured in an HIV-1-inducible reporter T cell line by flow cytometry. Recombinant viruses expressing subtype C Gag-proteases exhibited substantially lower replication capacities than those expressing subtype B Gag-proteases (p
The within-host population dynamics of Mycobacterium tuberculosis vary with treatment efficacy
Apr 20, 2017   Genome Biology
Trauner A, Liu Q, Via LE, Liu X, Ruan X,   . . . . . .   , England K, Zhang G, Gagneux S, Barry CE, Gao Q
The within-host population dynamics of Mycobacterium tuberculosis vary with treatment efficacy
Apr 20, 2017
Genome Biology
Combination therapy is one of the most effective tools for limiting the emergence of drug resistance in pathogens. Despite the widespread adoption of combination therapy across diseases, drug resistance rates continue to rise, leading to failing treatment regimens. The mechanisms underlying treatment failure are well studied, but the processes governing successful combination therapy are poorly understood. We address this question by studying the population dynamics of Mycobacterium tuberculosis within tuberculosis patients undergoing treatment with different combinations of antibiotics. By combining very deep whole genome sequencing (~1000-fold genome-wide coverage) with sequential sputum sampling, we were able to detect transient genetic diversity driven by the apparently continuous turnover of minor alleles, which could serve as the source of drug-resistant bacteria. However, we report that treatment efficacy has a clear impact on the population dynamics: sufficient drug pressure bears a clear signature of purifying selection leading to apparent genetic stability. In contrast, M. tuberculosis populations subject to less drug pressure show markedly different dynamics, including cases of acquisition of additional drug resistance. Our findings show that for a pathogen like M. tuberculosis, which is well adapted to the human host, purifying selection constrains the evolutionary trajectory to resistance in effectively treated individuals. Nonetheless, we also report a continuous turnover of minor variants, which could give rise to the emergence of drug resistance in cases of drug pressure weakening. Monitoring bacterial population dynamics could therefore provide an informative metric for assessing the efficacy of novel drug combinations.
Anthracyclines suppress pheochromocytoma cell characteristics, including metastasis, through inhibition of the hypoxia signaling pathway
Apr 20, 2017   Oncotarget
Pang Y, Yang C, Schovanek J, Wang H, Bullova P, Caisova V, Gupta G, Wolf KI, Semenza GL, Zhuang Z, Pacak K
Anthracyclines suppress pheochromocytoma cell characteristics, including metastasis, through inhibition of the hypoxia signaling pathway
Apr 20, 2017
Oncotarget
Pheochromocytomas (PHEOs) and paragangliomas (PGLs) are rare, neuroendocrine tumors derived from adrenal or extra-adrenal chromaffin cells, respectively. Metastases are discovered in 3-36% of patients at the time of diagnosis. Currently, only suboptimal treatment options exist. Therefore, new therapeutic compounds targeting metastatic PHEOs/PGLs are urgently needed. Here, we investigated if anthracyclines were able to suppress the progression of metastatic PHEO. We explored their effects on experimental mouse PHEO tumor cells using in vitro and in vivo models, and demonstrated that anthracyclines, particularly idarubicin (IDA), suppressed hypoxia signaling by preventing the binding of hypoxia-inducible factor 1 and 2 (HIF-1 and HIF-2) to the hypoxia response element (HRE) sites on DNA. This resulted in reduced transcriptional activation of HIF target genes, including erythropoietin (EPO), phosphoglycerate kinase 1 (PGK1), endothelin 1 (EDN1), glucose transporter 1 (GLUT1), lactate dehydrogenase A (LDHA), and vascular endothelial growth factor (VEGFA), which consequently inhibited the growth of metastatic PHEO. Additionally, IDA downregulated hypoxia signaling by interfering with the transcriptional activation of HIF1A and HIF2A. Furthermore, our animal model demonstrated the dose-dependent suppressive effect of IDA on metastatic PHEO growth in vivo. Our results indicate that anthracyclines are prospective candidates for inclusion in metastatic PHEO/PGL therapy, especially in patients with gene mutations involved in the hypoxia signaling pathway.
Glutathione Primes T Cell Metabolism for Inflammation
Apr 19, 2017   Immunity
Mak TW, Grusdat M, Duncan GS, Dostert C, Nonnenmacher Y,   . . . . . .   , Lang PA, Lohoff M, Harris IS, Hiller K, Brenner D
Glutathione Primes T Cell Metabolism for Inflammation
Apr 19, 2017
Immunity
Activated T cells produce reactive oxygen species (ROS), which trigger the antioxidative glutathione (GSH) response necessary to buffer rising ROS and prevent cellular damage. We report that GSH is essential for T cell effector functions through its regulation of metabolic activity. Conditional gene targeting of the catalytic subunit of glutamate cysteine ligase (Gclc) blocked GSH production specifically in murine T cells. Gclc-deficient T cells initially underwent normal activation but could not meet their increased energy and biosynthetic requirements. GSH deficiency compromised the activation of mammalian target of rapamycin-1 (mTOR) and expression of NFAT and Myc transcription factors, abrogating the energy utilization and Myc-dependent metabolic reprogramming that allows activated T cells to switch to glycolysis and glutaminolysis. In vivo, T-cell-specific ablation of murine Gclc prevented autoimmune disease but blocked antiviral defense. The antioxidative GSH pathway thus plays an unexpected role in metabolic integration and reprogramming during inflammatory T cell responses. Copyright © 2017 Elsevier Inc. All rights reserved.
Progress in HIV-1 antibody research using humanized mice
Apr 19, 2017   Current Opinion In HIV And AIDS
Gruell H, Klein F
Progress in HIV-1 antibody research using humanized mice
Apr 19, 2017
Current Opinion In HIV And AIDS
Recent discoveries of highly potent broadly HIV-1 neutralizing antibodies provide new opportunities to successfully prevent, treat, and potentially cure HIV-1 infection. To test their activity in vivo, humanized mice have been shown to be a powerful model and were used to investigate antibody-mediated prevention and therapy approaches. In this review, we will summarize recent findings in humanized mice that have informed on the potential use of broadly neutralizing antibodies targeting HIV-1 in humans. Humanized mouse models have been used to demonstrate the antiviral efficacy of HIV-1 neutralizing antibodies in vivo. It has been shown that a combination of antibodies can suppress viremia below the limit of detection and targets the HIV-1 reservoir. Moreover, passively administered antibodies and vector-mediated antibody production protect humanized mice from HIV-1 infection. Finally, immunization studies in knock-in/transgenic mice carrying human antibody gene segments have informed on potential vaccination strategies to induce broad and potent HIV-1 neutralizing antibodies. Humanized mouse models are of great value for HIV-1 research. They represent a highly versatile in vivo system to investigate novel approaches for HIV-1 prevention and therapy and expedite the critical translation from basic findings to clinical application.
Effect of hepatitis B virus subgenotype on antiviral response in nucleoside-treated hepatitis B e antigen-positive patients
Apr 19, 2017   Hepatology Research : The Official Journal Of The Japan Society Of Hepatology
Shen S, Liang X, Hamed K, Tanaka Y, Omagari K, Fan R, Xie Q, Tan D, Zhou B, Jia JD, Hou J, Sun J
Effect of hepatitis B virus subgenotype on antiviral response in nucleoside-treated hepatitis B e antigen-positive patients
Apr 19, 2017
Hepatology Research : The Official Journal Of The Japan Society Of Hepatology
Previous studies have reported that hepatitis B virus (HBV) genotype is not a predictor of treatment response with nucleos(t)ide analogue (NUC) therapy. However, the impact of subgenotype on treatment response is unknown. To identify the effect of HBV subgenotype on treatment response. In this retrospective study, the derivation dataset comprised patients from the EFFORT study (NCT00962533) telbivudine monotherapy group; patients infected with genotypes B or C from the GLOBE (NCT00057265) and 015 (NCT00131742) studies formed the validation dataset. HBV subgenotype was determined using phylogenetic analysis based on the surface or overlapping polymerase gene. Molecular modeling was used to investigate relationships between positions of the substitutions within reverse transcriptase and genotypic resistance. Of the patients in the derivation dataset, 110, 24, 162, and 1 patients were classified as having HBV subgenotypes B2, C1, C2, or other, respectively, compared to 222, 146, 282, and 51 in the validation dataset. Patients infected with subgenotype C1 showed higher virologic response rate and hepatitis B e antigen (HBeAg) seroconversion rate, and lower genotypic resistance rate than those infected with subgenotypes B2 and C2. Patients with genotypic resistance to telbivudine with subgenotype C1 showed fewer secondary mutations. The crystal structure model of reverse transcriptase showed that these secondary mutations were located around the YMDD motif, which possibly influenced the chance of mutations at rtM204. HBV subgenotype C1 is associated with better antiviral response to NUCs in HBeAg-positive patients than B2 and C2. The exact mechanism needs to be explored further. This article is protected by copyright. All rights reserved.
Erratum for Roth et al., "Flavivirus Infection Uncouples Translation Suppression from Cellular Stress Responses"
Apr 19, 2017   MBio
Roth H, Magg V, Uch F, Mutz P, Klein P, Haneke K, Lohmann V, Bartenschlager R, Fackler OT, Locker N, Stoecklin G, Ruggieri A
Bidirectional nucleolar dysfunction in C9orf72 frontotemporal lobar degeneration
Apr 19, 2017   Acta Neuropathologica Communications
Mizielinska S, Ridler CE, Balendra R, Thoeng A, Woodling NS, Grässer FA, Plagnol V, Lashley T, Partridge L, Isaacs AM
Bidirectional nucleolar dysfunction in C9orf72 frontotemporal lobar degeneration
Apr 19, 2017
Acta Neuropathologica Communications
An intronic GGGGCC expansion in C9orf72 is the most common known cause of both frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). The repeat expansion leads to the generation of sense and antisense repeat RNA aggregates and dipeptide repeat (DPR) proteins, generated by repeat-associated non-ATG translation. The arginine-rich DPR proteins poly(glycine-arginine or GR) and poly(proline-arginine or PR) are potently neurotoxic and can localise to the nucleolus when expressed in cells, resulting in enlarged nucleoli with disrupted functionality. Furthermore, GGGGCC repeat RNA can bind nucleolar proteins in vitro. However, the relevance of nucleolar stress is unclear, as the arginine-rich DPR proteins do not localise to the nucleolus in C9orf72-associated FTLD/ALS (C9FTLD/ALS) patient brain. We measured nucleolar size in C9FTLD frontal cortex neurons using a three-dimensional, volumetric approach. Intriguingly, we found that C9FTLD brain exhibited bidirectional nucleolar stress. C9FTLD neuronal nucleoli were significantly smaller than control neuronal nucleoli. However, within C9FTLD brains, neurons containing poly(GR) inclusions had significantly larger nucleolar volumes than neurons without poly(GR) inclusions. In addition, expression of poly(GR) in adult Drosophila neurons led to significantly enlarged nucleoli. A small but significant increase in nucleolar volume was also observed in C9FTLD frontal cortex neurons containing GGGGCC repeat-containing RNA foci. These data show that nucleolar abnormalities are a consistent feature of C9FTLD brain, but that diverse pathomechanisms are at play, involving both DPR protein and repeat RNA toxicity.
A novel ViewRNA in situ hybridization method for the detection of the dynamic distribution of Classical Swine Fever Virus RNA in PK15 cells
Apr 19, 2017   Virology Journal
Zhang Q, Xu L, Zhang Y, Wang T, Zou X, Zhu Y, Zhao Y, Li C, Chen K, Sun Y, Sun J, Zhao Q, Wang Q
A novel ViewRNA in situ hybridization method for the detection of the dynamic distribution of Classical Swine Fever Virus RNA in PK15 cells
Apr 19, 2017
Virology Journal
Classical swine fever (CSF) is a highly contagious fatal infectious disease caused by classical swine fever virus (CSFV). A better understanding of CSFV replication is important for the study of pathogenic mechanism of CSF. With the development of novel RNA in situ Hybridization method, quantitatively localization and visualization of the virus RNA molecular in cultured cell or tissue section becomes very important tool to address these pivotal pathogenic questions. In this study, we established ViewRNA ISH method to reveal the dynamic distribution of CSFV RNA in PK15 cells. We designed several specific probes of CSFV RNA and reference gene β-actin for host PK15 cells to monitor the relative location of CSFV RNA and house-keeping gene in the infected cells. After determining the titer of reference strain CSFV (HeBHH1/95) with the 50% tissue culture infective dose (TCID50), we optimized the protease K concentration and formalin fixation time to analyze the hybridization efficiency, fluorescence intensity and repeatability. In order to measure the sensitivity of this assay, we compared it with the fluorescent antibody test (FAT) and immunohistochemical(IHC) method. Specificity of the ViewRNA ISH was tested by detecting several sub genotypes of CSFV (sub genotype 1.1, 2.1, 2.2 and 2.3) which are present in China and other normal pig infectious virus (bovine viral diarrhea virus (BVDV), porcine parvovirus (PPV), porcine pseudorabies virus (PRV) and porcine circovirusII(PCV-2). The lowest detection threshold of the ViewRNA ISH method was 10-8, while the sensitivity of FAT and IHC were 10-5 and 10-4, respectively. The ViewRNA ISH was specific for CSFV RNA including 1.1, 2.1, 2.2 and 2.3 subtypes, meanwhile, there was no cross-reaction with negative control and other viruses including BVDV, PPV, PRV and PCV-2. Our results showed that after infection at 0.5 hpi (hours post inoculation, hpi), the CSFV RNA can be detected in nucleus and cytoplasm; during 3-9 hpi, RNA was mainly distributed in nucleus and reached a maximum at 12hpi, then RNA copy number was gradually increased around the cell nucleus during 24-48 hpi and reached the peak at 72hpi. To our knowledge, this is the first to reveal the dynamic distribution of medium virulence CSFV RNA in PK15 cells using the ViewRNA ISH method. The sensitivity of the ViewRNA ISH was three to four orders of magnitude higher than that of FAT and IHC methods. The specificity experiment showed that the ViewRNA ISH was highly specific for CSFV and no cross-reaction occurred to negative control and other pig infectious virus. This assay is more suitable for studying the CSFV RNA life cycle in cell nucleus. The results proved that CSFV RNA enters into PK15 cells earlier than 0.5hpi, relative to the eclipse period of cytoplasm is 6-9 hpi and CSFV RNA has ever existed in nucleus.
A humanized mouse-based HIV-1 viral outgrowth assay with higher sensitivity than in vitro qVOA in detecting latently infected cells from individuals on ART with undetectable viral loads
Apr 22, 2017   Virology
Charlins P, Schmitt K, Remling-Mulder L, Hogan LE, Hanhauser E, Hobbs KS, Hecht F, Deeks SG, Henrich TJ, Akkina R
A humanized mouse-based HIV-1 viral outgrowth assay with higher sensitivity than in vitro qVOA in detecting latently infected cells from individuals on ART with undetectable viral loads
Apr 22, 2017
Virology
Assays that can verify full viral eradication are essential in the context of achieving a cure for HIV/AIDS. In vitro quantitative viral out growth assays (qVOA) are currently the gold standard for measuring latent HIV-1 but these assays often fail to detect very low levels of replication-competent virus. Here we investigated an alternative in vivo approach for sensitive viral detection using humanized mice (hmVOA). Peripheral blood CD4+ T cell samples from HIV subjects on stable ART with undetectable viral loads by RT-PCR were first assayed by in vitro qVOA. Corresponding patient samples in which no virus was detected by qVOA were injected into humanized mice to allow viral outgrowth. Of the five qVOA virus negative samples, four gave positive viral outgrowth in the hmVOA assay suggesting that it is more sensitive in detecting latent HIV-1. Copyright © 2017. Published by Elsevier Inc.

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