Journal Name: Clinical Chemistry and Laboratory Medicine (CCLM)
Issue: Ahead of print
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Παρασκευή 26 Φεβρουαρίου 2016
Investigation on the ability of first trimester glycodelin and angiopoietin-2 to predict small-for-gestational age pregnancies at delivery
Identity Efficiency for High-Performance Ambient Pressure Ion Mobility Spectrometry
Analytical Chemistry
DOI: 10.1021/acs.analchem.5b03765
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Site-Specific Quantification of Surface N-Glycoproteins in Statin-Treated Liver Cells
Analytical Chemistry
DOI: 10.1021/acs.analchem.5b04871
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Vacuum Ultraviolet Photodissociation and Fourier Transform–Ion Cyclotron Resonance (FT-ICR) Mass Spectrometry: Revisited
Analytical Chemistry
DOI: 10.1021/acs.analchem.6b00148
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The Dorsal Scapular Nerve - Everything You Need To Know - Dr. Nabil Ebraheim
Educational video describing the anatomy of the dorsal scapular nerve.
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A Sporadic Neonatal Case of Epidermolysis Bullosa Simplex Generalized Intermediate with KRT5 and KRT14 Gene Mutations
AJP Rep 2016; 06: e108-e111
DOI: 10.1055/s-0035-1570386
Background Epidermolysis bullosa simplex (EBS) is a rare genodermatosis resulting from multiple gene mutations, including KRT5 and KRT14. The clinical expression of the mechanobullous skin fragility disease has not been fully explained by the genotype. Case Description An 11-day-old Japanese newborn infant was hospitalized because of herpetiform skin blistering on the feet, which expanded systemically after birth. There was no evidence of virus infection. The biopsied skin lesion showed a blister on the lamina densa without keratin clumps, indicating a diagnosis of EBS-generalized intermediate. We punctured the blisters to remove the contents daily, which led to no exacerbation or infection. The genetic study determined that the patient carried double substitutions of KRT5 c.1424A > G (p.E475G) and KRT14 c.1237G > A (p.A413T). The asymptomatic mother and sister carried the KRT14 substitution, but the healthy father had no substitution of the KRT gene. Conclusion This is the first report of EBS-generalized intermediate in a newborn with de novo KRT5 gene mutation and KRT14 gene polymorphism, and no familial history of epidermolysis. Neonatal blistering due to EBS requires optimal skin management after excluding infectious and immunobullous diseases.
[...]
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Article in Thieme eJournals:
Table of contents | Abstract | open access Full text
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Septo-Optic Dysplasia in a Newborn Presenting with Bilateral Dilated and Fixed Pupils
AJP Rep 2016; 06: e112-e114
DOI: 10.1055/s-0036-1571330
Introduction We describe a newborn female infant with septo-optic dysplasia (SOD) presenting with bilateral dilated and fixed pupils. Conclusion Our report is unique because the incidental finding of bilateral dilated and fixed pupils on the newborn exam was the only clinical finding which led to a prompt work-up and eventual diagnosis of SOD.
[...]
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Article in Thieme eJournals:
Table of contents | Abstract | open access Full text
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Consensus Definitions for Sepsis and Septic Shock
This video presents updated definitions of and clinical criteria for diagnosing sepsis and septic shock based on recommendations from an expert task force. Learn more at http://jamasepsis.com.
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Retrospective study of prenatal ultrasound findings in newborns with a Noonan spectrum disorder
Abstract
Objectives
Noonan spectrum disorders (NSDs) occur in 1:1,000-2,500 live births. Currently, there are no guidelines for prenatal molecular genetic testing for NSDs. Recent studies recommend prenatal testing for NSDs when ultrasonography detects two or more associated abnormalities. A stronger association between ultrasound findings and NSDs would enable more informed prenatal genetic testing. This article is protected by copyright. All rights reserved.
Methods
212 newborns (0-12 weeks) with prenatal ultrasound findings and a clinical suspicion of a NSD were referred for molecular genetic testing. Of these, 159/212 newborns tested had a single ultrasound abnormality and 53/212 newborns had two or more. Testing was performed by either a microarray-based resequencing assay or next generation sequencing of RAS/MAPK pathway genes associated with NSDs. Prenatal ultrasound findings in positive and negative cases were compared.
Results
A disease-causing variant was identified in 21.7% (46/212) of newborns tested. Of these positive cases, 67.4% (31/46) had only one ultrasound abnormality reported. The rate of detecting a disease-causing variant in cases with one ultrasound finding was 19.5% (31/159), which was not significantly different (p-value =0.36) than that in cases with two or more ultrasound findings (28.3%; 15/53).
Conclusions
Prenatal molecular testing for NSDs should be considered even in the presence of a single associated abnormal ultrasound finding.
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Imaging Serotonergic Fibers in the Mouse Spinal Cord Using the CLARITY/CUBIC Technique
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Determination of Photoreceptor Cell Spectral Sensitivity in an Insect Model from In Vivo Intracellular Recordings
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A Vacuum Ultraviolet Absorption Array Spectrometer as a Selective Detector for Comprehensive Two-Dimensional Gas Chromatography: Concept and First Results
Analytical Chemistry
DOI: 10.1021/acs.analchem.5b02472
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Technical Note: Preferred dosimeter size and associated correction factors in commissioning high dose per pulse, flattening filter free x-ray beams
Purpose:
High dose rate flattening filter free (FFF) beams pose new challenges and considerations for accurate reference and relative dosimetry. The authors report errors associated with commonly used ion chambers and introduce simple methods to mitigate them.
Methods:
Dosimetric errors due to (1) ion recombination effects of high dose per pulse (DPP) FFF beams and (2) volume-averaging effects of the radial profile were examined on a TrueBeam STx. Four commonly used cylindrical ion chambers spanning a range of lengths (0.29–2.3 cm) and volumes (0.016–0.6 cm3) were used to determine the magnitude of these effects for 6 and 10 MV unflattened x-ray beams (6XFFF and 10XFFF, respectively). Two methods were used to determine the magnitude of ion collection efficiency: (1) direct measurement of the percent depth dose (PDD) for the clinical, high DPP beam in comparison to that obtained after reducing the DPP and (2) measurement of Pion as a function of depth. Two methods were used to quantify the magnitude of volume-averaging: (1) direct measurement of volume-averaging via cross-calibration and (2) calculation of volume-averaging from radial profiles of the beam. Finally, a simple analytical expression for the radial profile volume-averaging correction factor, Prp = [OAR(0.29L)]−1, or the inverse of the off-axis ratio of dose at 0.29L, where L is the length of the chamber's sensitive volume, is introduced to mitigate the volume-averaging effect in Farmer-type chambers.
Results:
Errors in measured PDD for the clinical beams were 1.3% ± 0.07% and 1.6% ± 0.07% at 35 cm depth for the 6XFFF and 10XFFF beam, respectively, using an IBA CC13 ion chamber, due to charge recombination with a high DPP. Volume-averaging effects were 0.4% and 0.7% for the 6XFFF and 10XFFF beam, respectively, when measured with a Farmer-type chamber. For the application of TG-51, these errors combine when using a CC13 to measure the PDD and a Farmer for absolute output dosimetry for a total error of up to 2% at dmax for the 10XFFF beam.
Conclusions:
Relative and absolute dosimetry in high DPP, unflattened x-ray beams of 10 MV or higher requires corrections for charge recombination and/or volume-averaging when dosimeters with certain geometries are used. Chambers used for PDD measurement are available that do not require a correction for charge recombination. A simple analytical expression of the correction factor Prp was introduced in this work to account for volume-averaging effects in Farmer chambers. Choice of an appropriate dosimeter coupled with application of the established correction factors Pion and Prp reduces the uncertainty in the PDD measurement and the reference dose measurement.
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Application of systems and control theory-based hazard analysis to radiation oncology
Purpose:
Both humans and software are notoriously challenging to account for in traditional hazard analysis models. The purpose of this work is to investigate and demonstrate the application of a new, extended accident causality model, called systems theoretic accident model and processes (STAMP), to radiationoncology. Specifically, a hazard analysis technique based on STAMP, system-theoretic process analysis (STPA), is used to perform a hazard analysis.
Methods:
The STPA procedure starts with the definition of high-level accidents for radiationoncology at the medical center and the hazards leading to those accidents. From there, the hierarchical safety control structure of the radiationoncology clinic is modeled, i.e., the controls that are used to prevent accidents and provide effective treatment. Using STPA, unsafe control actions (behaviors) are identified that can lead to the hazards as well as causal scenarios that can lead to the identified unsafe control. This information can be used to eliminate or mitigate potential hazards. The STPA procedure is demonstrated on a new online adaptive cranial radiosurgery procedure that omits the CT simulation step and uses CBCT for localization, planning, and surface imaging system during treatment.
Results:
The STPA procedure generated a comprehensive set of causal scenarios that are traced back to system hazards and accidents. Ten control loops were created for the new SRS procedure, which covered the areas of hospital and department management, treatment design and delivery, and vendor service. Eighty three unsafe control actions were identified as well as 472 causal scenarios that could lead to those unsafe control actions.
Conclusions:
STPA provides a method for understanding the role of management decisions and hospital operations on system safety and generating process design requirements to prevent hazards and accidents. The interaction of people, hardware, and software is highlighted. The method of STPA produces results that can be used to improve safety and prevent accidents and warrants further investigation.
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Quantifying Fish Swimming Behavior in Response to Acute Exposure of Aqueous Copper Using Computer Assisted Video and Digital Image Analysis
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The influence of (central) auditory processing disorder on the severity of speech-sound disorders in children
OBJECTIVE: To identify a cutoff value based on the Percentage of Consonants Correct-Revised index that could indicate the likelihood of a child with a speech-sound disorder also having a (central) auditory processing disorder . METHODS: Language, audiological and (central) auditory processing evaluations were administered. The participants were 27 subjects with speech-sound disorders aged 7 to 10 years and 11 months who were divided into two different groups according to their (central) auditory processing evaluation results. RESULTS: When a (central) auditory processing disorder was present in association with a speech disorder, the children tended to have lower scores on phonological assessments. A greater severity of speech disorder was related to a greater probability of the child having a (central) auditory processing disorder. The use of a cutoff value for the Percentage of Consonants Correct-Revised index successfully distinguished between children with and without a (central) auditory processing disorder. CONCLUSIONS: The severity of speech-sound disorder in children was influenced by the presence of (central) auditory processing disorder. The attempt to identify a cutoff value based on a severity index was successful.
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Comparison between refraction measured by Spot Vision ScreeningTM and subjective clinical refractometry
OBJECTIVE: The purpose of this study was to evaluate the accuracy of Spot Vision ScreeningTM as an autorefractor by comparing refraction measurements to subjective clinical refractometry results in children and adult patients. METHODS: One-hundred and thirty-four eyes of 134 patients were submitted to refractometry by Spot and clinical refractometry under cycloplegia. Patients, students, physicians, staff and children of staff from the Hospital das Clínicas (School of Medicine, University of São Paulo) aged 7-50 years without signs of ocular disease were examined. Only right-eye refraction data were analyzed. The findings were converted in magnitude vectors for analysis. RESULTS: The difference between Spot Vision ScreeningTM and subjective clinical refractometry expressed in spherical equivalents was +0.66±0.56 diopters (D), +0.16±0.27 D for the vector projected on the 90 axis and +0.02±0.15 D for the oblique vector. CONCLUSIONS: Despite the statistical significance of the difference between the two methods, we consider the difference non-relevant in a clinical setting, supporting the use of Spot Vision ScreeningTM as an ancillary method for estimating refraction.
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Clinical evaluation, biochemistry and genetic polymorphism analysis for the diagnosis of lactose intolerance in a population from northeastern Brazil
OBJECTIVE: This work aimed to evaluate and correlate symptoms, biochemical blood test results and single nucleotide polymorphisms for lactose intolerance diagnosis. METHOD: A cross-sectional study was conducted in Fortaleza, Ceará, Brazil, with a total of 119 patients, 54 of whom were lactose intolerant. Clinical evaluation and biochemical blood tests were conducted after lactose ingestion and blood samples were collected for genotyping evaluation. In particular, the single nucleotide polymorphisms C>T-13910 and G>A-22018 were analyzed by restriction fragment length polymorphism/polymerase chain reaction and validated by DNA sequencing. RESULTS: Lactose-intolerant patients presented with more symptoms of flatulence (81.4%), bloating (68.5%), borborygmus (59.3%) and diarrhea (46.3%) compared with non-lactose-intolerant patients (p<0.05). We observed a significant association between the presence of the alleles T-13910 and A-22018 and the lactose-tolerant phenotype (p<0.05). After evaluation of the biochemical blood test results for lactose, we found that the most effective cutoff for glucose levels obtained for lactose malabsorbers was <15 mg/dL, presenting an area under the receiver operating characteristic curve greater than 80.3%, with satisfactory values for sensitivity and specificity. CONCLUSIONS: These data corroborate the association of these single nucleotide polymorphisms (C>T-13910 and G>A-22018) with lactose tolerance in this population and suggest clinical management for patients with lactose intolerance that considers single nucleotide polymorphism detection and a change in the biochemical blood test cutoff from <25 mg/dL to <15 mg/dL.
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Associations of HIV testing and late diagnosis at a Japanese university hospital
OBJECTIVES: This study was conducted to clarify the rate of late diagnosis of HIV infection and to identify relationships between the reasons for HIV testing and a late diagnosis. METHODS: This retrospective cohort study was conducted among HIV-positive patients at the Jikei University Hospital between 2001 and 2014. Patient characteristics from medical records, including age, sex, sexuality, the reason for HIV testing and the number of CD4-positive lymphocytes at HIV diagnosis, were assessed. RESULTS: A total of 459 patients (men, n=437; 95.2%) were included in this study and the median age at HIV diagnosis was 36 years (range, 18-71 years). Late (CD4 cell count <350/mm3) and very late (CD4 cell count <200/mm3) diagnoses were observed in 61.4% (282/459) and 36.6% (168/459) of patients, respectively. The most common reason for HIV diagnosis was voluntary testing (38.6%, 177/459 patients), followed by AIDS-defining illness (18.3%, 84/459 patients). Multivariate analysis revealed a significant association of voluntary HIV testing with non-late and non-very-late diagnoses and there was a high proportion of AIDS-defining illness in the late and very late diagnosis groups compared with other groups. Men who have sex with men was a relative factor for non-late diagnosis, whereas nonspecific abnormal blood test results, such as hypergammaglobulinemia and thrombocytopenia, were risk factors for very late diagnosis. CONCLUSIONS: Voluntary HIV testing should be encouraged and physicians should screen all patients who have symptoms or signs and particularly hypergammaglobulinemia and thrombocytopenia, that may nonspecifically indicate HIV infection.
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Analyses of balance and flexibility of obese patients undergoing bariatric surgery
OBJECTIVE: To assess the postural control and flexibility of obese subjects before and both six and 12 months after bariatric surgery. To verify whether postural control is related to flexibility following weight reductions resulting from bariatric surgery. METHODS: The sample consisted of 16 subjects who had undergone bariatric surgery. All assessments were performed before and six and 12 months after bariatric surgery. Postural balance was assessed using an Accusuway¯ portable force platform, and flexibility was assessed using a standard chair sit and reach test (Wells' chair). RESULTS: With the force platform, no differences were observed in the displacement area or velocity from the center of pressure in the mediolateral and anteroposterior directions. The displacement speed from the center of pressure was decreased at the six month after the surgery; however, unchanged from baseline at 12 months post-surgery. Flexibility increased over time according to the three measurements tested. CONCLUSIONS: Static postural balance did not change. The velocity of postural adjustment responses were increased at six months after surgery. Therefore, weight loss promotes increased flexibility. Yet, improvements in flexibility are not related to improvements in balance.
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Analysis of the Ki-67 index in the vaginal epithelium of castrated rats treated with tamoxifen
OBJECTIVES: Vaginal atrophy and breast cancer are common conditions in postmenopausal women and tamoxifen is the standard endocrine treatment for hormone-sensitive tumors. The present study aimed to assess the effect of tamoxifen on Ki-67 protein expression in the vaginal epithelium of castrated rats. MATERIAL AND METHODS: Forty Wistar-Hannover adult, virgin, castrated rats were randomly divided into two groups, group I (control, n=20) and group II (tamoxifen, n=20), receiving 0.5 ml of propylene glycol and 250 µg of tamoxifen diluted in 0.5 ml of propylene glycol, respectively, daily by gavage for 30 days. On the 31st day, the rats were euthanized and their vaginas were removed and fixed in 10% buffered formalin for the immunohistochemical study of Ki-67 protein expression. Data were analyzed by the Levene and Student's t tests (p<0.05). RESULTS: The mean index of Ki-67 expression in the rat vagina of groups I and II was 4.04±0.96 and 26.86±2.19, respectively (p<0.001). CONCLUSIONS: According to the results of the present study, tamoxifen, at the dose and treatment length used, induced a significant increase in the cell proliferation of the vaginal mucosa in castrated rats, as evaluated by Ki-67 protein expression.
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The efficacy and safety of urethral injection therapy for urinary incontinence in women: a systematic review
To evaluate the efficacy and safety of different bulking agents for treating urinary incontinence in women, a systematic review including only randomized controlled trials was performed. The subjects were women with urinary incontinence. The primary outcomes were clinical and urodynamic parameters. The results were presented as a weighted mean difference for non-continuous variables and as relative risk for continuous variables, both with 95% confidence intervals. Initially, 942 studies were identified. However, only fourteen eligible trials fulfilled the prerequisites. Altogether, the review included 1814 patients in trials of eight different types of bulking agents, and all studies were described and analyzed. The measured outcomes were evaluated using a large variety of instruments. The most common complications of the bulking agents were urinary retention and urinary tract infection. Additionally, there were certain major complications, such as one case of death after use of autologous fat. However, the lack of adequate studies, the heterogeneous populations studied, the wide variety of materials used and the lack of long-term follow-up limit guidance of practice. To determine which substance is the most suitable, there is a need for more randomized clinical trials that compare existing bulking agents based on standardized clinical outcomes.
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Spine radiosurgery for the local treatment of spine metastases: Intensity-modulated radiotherapy, image guidance, clinical aspects and future directions
Many cancer patients will develop spinal metastases. Local control is important for preventing neurologic compromise and to relieve pain. Stereotactic body radiotherapy or spinal radiosurgery is a new radiation therapy technique for spinal metastasis that can deliver a high dose of radiation to a tumor while minimizing the radiation delivered to healthy, neighboring tissues. This treatment is based on intensity-modulated radiotherapy, image guidance and rigid immobilization. Spinal radiosurgery is an increasingly utilized treatment method that improves local control and pain relief after delivering ablative doses of radiation. Here, we present a review highlighting the use of spinal radiosurgery for the treatment of metastatic tumors of the spine. The data used in the review were collected from both published studies and ongoing trials. We found that spinal radiosurgery is safe and provides excellent tumor control (up to 94% local control) and pain relief (up to 96%), independent of histology. Extensive data regarding clinical outcomes are available; however, this information has primarily been generated from retrospective and nonrandomized prospective series. Currently, two randomized trials are enrolling patients to study clinical applications of fractionation schedules spinal Radiosurgery. Additionally, a phase I clinical trial is being conducted to assess the safety of concurrent stereotactic body radiotherapy and ipilimumab for spinal metastases. Clinical trials to refine clinical indications and dose fractionation are ongoing. The concomitant use of targeted agents may produce better outcomes in the future.
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Clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation: a meta-analysis of seven case-control studies
The purpose of this study was to evaluate the clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation. We searched the PubMed, Embase and Web of Science databases and included all case-control trials that reported on the clinical outcomes of osteonecrosis progression, incidence of total hip arthroplasty and improvement in Harris hip scores. Overall, seven case-control trials were included. Compared with the controls, patients treated with the bone marrow stem cells implantation treatment showed improved clinical outcomes with delayed osteonecrosis progression (odds ratio = 0.17, 95% CI: 0.09 - 0.32; p <0.001), a lower total hip arthroplasty incidence (odds ratio = 0.30, 95% CI: 0.12 - 0.72; p <0.01) and increased Harris hip scores (mean difference = 4.76, 95% CI: 1.24 - 8.28; p<0.01). The heterogeneity, publication bias, and sensitivity analyses showed no statistical difference significant differences between studies. Thus, our study suggests that autologous bone marrow stem cells implantation has a good therapeutic effect on osteonecrosis of the femoral, resulting in beneficial clinical outcomes. However, trials with larger sample sizes are needed to confirm these findings.
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Simultaneous determination of estrogens (ethinylestradiol and norgestimate) concentrations in human and bovine serum albumin by use of fluorescence spectroscopy and multivariate regression analysis
Publication date: 15 May 2016
Source:Talanta, Volume 152
Author(s): LaQuana N. Hordge, Kiara L. McDaniel, Derick D. Jones, Sayo O. Fakayode
The endocrine disruption property of estrogens necessitates the immediate need for effective monitoring and development of analytical protocols for their analyses in biological and human specimens. This study explores the first combined utility of a steady-state fluorescence spectroscopy and multivariate partial-least-square (PLS) regression analysis for the simultaneous determination of two estrogens (17α-ethinylestradiol (EE) and norgestimate (NOR)) concentrations in bovine serum albumin (BSA) and human serum albumin (HSA) samples. The influence of EE and NOR concentrations and temperature on the emission spectra of EE-HSA EE-BSA, NOR-HSA, and NOR-BSA complexes was also investigated. The binding of EE with HSA and BSA resulted in increase in emission characteristics of HSA and BSA and a significant blue spectra shift. In contrast, the interaction of NOR with HSA and BSA quenched the emission characteristics of HSA and BSA. The observed emission spectral shifts preclude the effective use of traditional univariate regression analysis of fluorescent data for the determination of EE and NOR concentrations in HSA and BSA samples. Multivariate partial-least-squares (PLS) regression analysis was utilized to correlate the changes in emission spectra with EE and NOR concentrations in HSA and BSA samples. The figures-of-merit of the developed PLS regression models were excellent, with limits of detection as low as 1.6×10−8M for EE and 2.4×10−7M for NOR and good linearity (R2>0.994985). The PLS models correctly predicted EE and NOR concentrations in independent validation HSA and BSA samples with a root-mean-square-percent-relative-error (RMS%RE) of less than 6.0% at physiological condition. On the contrary, the use of univariate regression resulted in poor predictions of EE and NOR in HSA and BSA samples, with RMS%RE larger than 40% at physiological conditions. High accuracy, low sensitivity, simplicity, low-cost with no prior analyte extraction or separation required makes this method promising, compelling, and attractive alternative for the rapid determination of estrogen concentrations in biomedical and biological specimens, pharmaceuticals, or environmental samples.
Graphical abstract
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Mortality rates by occupation in Korea: a nationwide, 13-year follow-up study
Objective
The present study sought to identify inequalities in cause-specific mortality across different occupational groups in Korea.
MethodsThe cohort included Korean workers enrolled in the national employment insurance programme between 1995 and 2000. Mortality was determined by matching death between 1995 and 2008 according to a nationwide registry of the Korea National Statistical Office. The cohort was divided into nine occupational groups according to the Korean Standard Occupational Classification (KSOC). Age-standardised mortality rates of each subcohort were calculated.
ResultsThe highest age-standardised mortality rate was identified in KSOC 6 (agricultural, forestry and fishery workers; male (M): 563.0 per 100 000, female (F): 206.0 per 100 000), followed by KSOC 9 (elementary occupations; M: 499.0, F: 163.4) and KSOC 8 (plant, machine operators and assemblers; M: 380.3, F: 157.8). The lowest rate occurred in KSOC 2 (professionals and related workers; M: 209.1, F: 93.3). Differences in mortality rates between KSOC 2 and KSOC 9 (M: 289.9, F: 70.1) and the rate ratio of KSCO9 to KSCO2 (M: 2.39, F: 1.75) were higher in men. The most prominent mortality rate difference was observed in external causes of death (M: 96.9, F: 21.6) and liver disease in men (38.3 per 100 000). Mental disease showed the highest rate ratio (M: 6.31, F: 13.00).
ConclusionsSubstantial differences in mortality rates by occupation were identified. Main causes of death were injury, suicide and male liver disease. Development of policies to support occupations linked with a lower socioeconomic position should be prioritised.
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Hemagglutinin Stalk Immunity Reduces Influenza Virus Replication and Transmission in Ferrets [Vaccines and Antiviral Agents]
We assessed whether influenza virus hemagglutinin stalk-based immunity protects ferrets against aerosol-transmitted H1N1 influenza virus infection. Immunization of ferrets by a universal influenza virus vaccine strategy based on viral vectors expressing chimeric hemagglutinin constructs induced stalk-specific antibody responses. Stalk-immunized ferrets were cohoused with H1N1-infected ferrets under conditions that permitted virus transmission. Hemagglutinin stalk-immunized ferrets had lower viral titers and delayed or no virus replication at all following natural exposure to influenza virus.
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Characterization of Antibody Bipolar Bridging Mediated by the Human Cytomegalovirus Fc Receptor gp68 [Virus-Cell Interactions]
The human cytomegalovirus glycoprotein gp68 functions as an Fc receptor for host IgGs and can form antibody bipolar bridging (ABB) complexes in which gp68 binds the Fc region of an antigen-bound IgG. Here we show that gp68-mediated endocytosis transports ABB complexes into endosomes, after which the complex is routed to lysosomes, presumably for degradation. These results suggest gp68 contributes to evasion of IgG-mediated immune responses by mediating destruction of host IgG and viral antigens.
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Analysis of Assembly and Budding of Lujo Virus [Virus-Cell Interactions]
The recently identified arenavirus Lujo virus (LUJV) causes fatal hemorrhagic fever in humans. We analyzed its mechanism of viral release driven by matrix protein Z and the cell surface glycoprotein precursor GPC. The L domains in Z are required for efficient virus-like particle release, but Tsg101, ALIX/AIP1, and Vps4A/B are unnecessary for budding. LUJV GPC is cleaved by site 1 protease (S1P) at the RKLM motif, and treatment with the S1P inhibitor PF-429242 reduced LUJV production.
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Isolation and Characterization of a Novel Bat Coronavirus Closely Related to the Direct Progenitor of Severe Acute Respiratory Syndrome Coronavirus [Genetic Diversity and Evolution]
We report the isolation and characterization of a novel bat coronavirus which is much closer to the severe acute respiratory syndrome coronavirus (SARS-CoV) in genomic sequence than others previously reported, particularly in its S gene. Cell entry and susceptibility studies indicated that this virus can use ACE2 as a receptor and infect animal and human cell lines. Our results provide further evidence of the bat origin of the SARS-CoV and highlight the likelihood of future bat coronavirus emergence in humans.
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Nonstructural 5A Protein of Hepatitis C Virus Regulates Soluble Resistance-Related Calcium-Binding Protein Activity for Viral Propagation [Virus-Cell Interactions]
Hepatitis C virus (HCV) is a major cause of chronic liver disease and is highly dependent on cellular proteins for virus propagation. To identify the cellular factors involved in HCV propagation, we recently performed protein microarray assays using the HCV nonstructural 5A (NS5A) protein as a probe. Of 90 cellular protein candidates, we selected the soluble resistance-related calcium-binding protein (sorcin) for further characterization. Sorcin is a calcium-binding protein and is highly expressed in certain cancer cells. We verified that NS5A interacted with sorcin through domain I of NS5A, and phosphorylation of the threonine residue 155 of sorcin played a crucial role in protein interaction. Small interfering RNA (siRNA)-mediated knockdown of sorcin impaired HCV propagation. Silencing of sorcin expression resulted in a decrease of HCV assembly without affecting HCV RNA and protein levels. We further demonstrated that polo-like kinase 1 (PLK1)-mediated phosphorylation of sorcin was increased by NS5A. We showed that both phosphorylation and calcium-binding activity of sorcin were required for HCV propagation. These data indicate that HCV modulates sorcin activity via NS5A protein for its own propagation.
IMPORTANCE Sorcin is a calcium-binding protein and regulates intracellular calcium homeostasis. HCV NS5A interacts with sorcin, and phosphorylation of sorcin is required for protein interaction. Gene silencing of sorcin impaired HCV propagation at the assembly step of the HCV life cycle. Sorcin is phosphorylated by PLK1 via protein interaction. We showed that sorcin interacted with both NS5A and PLK1, and PLK1-mediated phosphorylation of sorcin was increased by NS5A. Moreover, calcium-binding activity of sorcin played a crucial role in HCV propagation. These data provide evidence that HCV regulates host calcium metabolism for virus propagation, and thus manipulation of sorcin activity may represent a novel therapeutic target for HCV.
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Structure-Guided Redesign Increases the Propensity of HIV Env To Generate Highly Stable Soluble Trimers [Vaccines and Antiviral Agents]
Due to high viral diversity, an effective HIV-1 vaccine will likely require Envs derived from multiple subtypes to generate broadly neutralizing antibodies (bNAbs). Soluble Env mimics, like the native flexibly linked (NFL) and SOSIP trimers, derived from the subtype A BG505 Env, form homogeneous, stable native-like trimers. However, other Env sequences, such as JRFL and 16055 from subtypes B and C, do so to a lesser degree. The high-resolution BG505 SOSIP crystal structures permit the identification and redesign of Env elements involved in trimer stability. Here, we identified structure trimer-derived (TD) residues that increased the propensity of the subtype B JRFL and subtype C 16055 Env sequences to form well-ordered, homogenous, and highly stable soluble trimers. The generation of these spike mimics no longer required antibody-based selection, positive or negative. Using the redesigned subtype B and C trimer representatives as respective foundations, we further stabilized the NFL TD trimers by engineering an intraprotomer disulfide linkage in the prebridging sheet, I201C-A433C (CC), that locks the gp120 in the receptor nontriggered state. We demonstrated that this disulfide pair prevented CD4 induced-conformational rearrangements in NFL trimers derived from the prototypic subtype A, B, and C representatives. Coupling the TD-based design with the engineered disulfide linkage, CC, increased the propensity of Env to form soluble highly stable spike mimics that are resistant to CD4-induced changes. These advances will allow testing of the hypothesis that such stabilized immunogens will more efficiently elicit neutralizing antibodies in small-animal models and primates.
IMPORTANCE HIV-1 displays unprecedented global diversity circulating in the human population. Since the envelope glycoprotein (Env) is the target of neutralizing antibodies, Env-based vaccine candidates that address such diversity are needed. Soluble well-ordered Env mimics, typified by NFL and SOSIP trimers, are attractive vaccine candidates. However, the current designs do not allow most Envs to form well-ordered trimers. Here, we made design modifications to increase the propensity of representatives from two of the major HIV subtypes to form highly stable trimers. This approach should be applicable to other viral Envs, permitting the generation of a repertoire of homogeneous, highly stable trimers. The availability of such an array will allow us to assess if sequential or cocktail immune strategies can overcome some of the vaccine challenges presented by HIV diversity.
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Activation of RNase L by Murine Coronavirus in Myeloid Cells Is Dependent on Basal Oas Gene Expression and Independent of Virus-Induced Interferon [Pathogenesis and Immunity]
The oligoadenylate synthetase (OAS)-RNase L pathway is a potent interferon (IFN)-induced antiviral activity. Upon sensing double-stranded RNA, OAS produces 2',5'-oligoadenylates (2-5A), which activate RNase L. Murine coronavirus (mouse hepatitis virus [MHV]) nonstructural protein 2 (ns2) is a 2',5'-phosphodiesterase (PDE) that cleaves 2-5A, thereby antagonizing RNase L activation. PDE activity is required for robust replication in myeloid cells, as a mutant of MHV (ns2H126R) encoding an inactive PDE fails to antagonize RNase L activation and replicates poorly in bone marrow-derived macrophages (BMM), while ns2H126R replicates to high titer in several types of nonmyeloid cells, as well as in IFN receptor-deficient (Ifnar1–/–) BMM. We reported previously that myeloid cells express significantly higher basal levels of OAS transcripts than nonmyeloid cells. Here, we investigated the contributions of Oas gene expression, basal IFN signaling, and virus-induced IFN to RNase L activation. Infection with ns2H126R activated RNase L in Ifih1–/– BMM to a similar extent as in wild-type (WT) BMM, despite the lack of IFN induction in the absence of MDA5 expression. However, ns2H126R failed to induce RNase L activation in BMM treated with IFNAR1-blocking antibody, as well as in Ifnar1–/– BMM, both expressing low basal levels of Oas genes. Thus, activation of RNase L does not require virus-induced IFN but rather correlates with adequate levels of basal Oas gene expression, maintained by basal IFN signaling. Finally, overexpression of RNase L is not sufficient to compensate for inadequate basal OAS levels.
IMPORTANCE The oligoadenylate synthetase (OAS)-RNase L pathway is a potent antiviral activity. Activation of RNase L during murine coronavirus (mouse hepatitis virus [MHV]) infection of myeloid cells correlates with high basal Oas gene expression and is independent of virus-induced interferon secretion. Thus, our data suggest that cells with high basal Oas gene expression levels can activate RNase L and thereby inhibit virus replication early in infection upon exposure to viral double-stranded RNA (dsRNA) before the induction of interferon and prior to transcription of interferon-stimulated antiviral genes. These findings challenge the notion that activation of the OAS-RNase L pathway requires virus to induce type I IFN, which in turn upregulates OAS gene expression, as well as to provide dsRNA to activate OAS. Our data further suggest that myeloid cells may serve as sentinels to restrict viral replication, thus protecting other cell types from infection.
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Neuropeptide Y Negatively Influences Monocyte Recruitment to the Central Nervous System during Retrovirus Infection [Pathogenesis and Immunity]
Monocyte infiltration into the CNS is a hallmark of several viral infections of the central nervous system (CNS), including retrovirus infection. Understanding the factors that mediate monocyte migration in the CNS is essential for the development of therapeutics that can alter the disease process. In the current study, we found that neuropeptide Y (NPY) suppressed monocyte recruitment to the CNS in a mouse model of polytropic retrovirus infection. NPY–/– mice had increased incidence and kinetics of retrovirus-induced neurological disease, which correlated with a significant increase in monocytes in the CNS compared to wild-type mice. Both Ly6Chi inflammatory and Ly6Clo alternatively activated monocytes were increased in the CNS of NPY–/– mice following virus infection, suggesting that NPY suppresses the infiltration of both cell types. Ex vivo analysis of myeloid cells from brain tissue demonstrated that infiltrating monocytes expressed high levels of the NPY receptor Y2R. Correlating with the expression of Y2R on monocytes, treatment of NPY–/– mice with a truncated, Y2R-specific NPY peptide suppressed the incidence of retrovirus-induced neurological disease. These data demonstrate a clear role for NPY as a negative regulator of monocyte recruitment into the CNS and provide a new mechanism for suppression of retrovirus-induced neurological disease.
IMPORTANCE Monocyte recruitment to the brain is associated with multiple neurological diseases. However, the factors that influence the recruitment of these cells to the brain are still not well understood. In the current study, we found that neuropeptide Y, a protein produced by neurons, affected monocyte recruitment to the brain during retrovirus infection. We show that mice deficient in NPY have increased influx of monocytes into the brain and that this increase in monocytes correlates with neurological-disease development. These studies provide a mechanism by which the nervous system, through the production of NPY, can suppress monocyte trafficking to the brain and reduce retrovirus-induced neurological disease.
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Antibody Response to Hypervariable Region 1 Interferes with Broadly Neutralizing Antibodies to Hepatitis C Virus [Pathogenesis and Immunity]
Hypervariable region 1 (HVR1) (amino acids [aa] 384 to 410) on the E2 glycoprotein of hepatitis C virus contributes to persistent infection by evolving escape mutations that attenuate binding of inhibitory antibodies and by blocking access of broadly neutralizing antibodies to their epitopes. A third proposed mechanism of immune antagonism is that poorly neutralizing antibodies binding to HVR1 interfere with binding of other superior neutralizing antibodies. Epitope mapping of human monoclonal antibodies (HMAbs) that bind to an adjacent, conserved domain on E2 encompassing aa 412 to 423 revealed two subsets, designated HC33 HMAbs. While both subsets have contact residues within aa 412 to 423, alanine-scanning mutagenesis suggested that one subset, which includes HC33.8, has an additional contact residue within HVR1. To test for interference of anti-HVR1 antibodies with binding of antibodies to aa 412 to 423 and other E2 determinants recognized by broadly neutralizing HMAbs, two murine MAbs against HVR1 (H77.16) and aa 412 to 423 (H77.39) were studied. As expected, H77.39 inhibited the binding of all HC33 HMAbs. Unexpectedly, H77.16 also inhibited the binding of both subsets of HC33 HMAbs. This inhibition also was observed against other broadly neutralizing HMAbs to epitopes outside aa 412 to 423. Combination antibody neutralization studies by the median-effect analysis method with H77.16 and broadly reactive HMAbs revealed antagonism between these antibodies. Structural studies demonstrated conformational flexibility in this antigenic region, which supports the possibility of anti-HVR1 antibodies hindering the binding of broadly neutralizing MAbs. These findings support the hypothesis that anti-HVR1 antibodies can interfere with a protective humoral response against HCV infection.
IMPORTANCE HVR1 contributes to persistent infection by evolving mutations that escape from neutralizing antibodies to HVR1 and by shielding broadly neutralizing antibodies from their epitopes. This study provides insight into a new immune antagonism mechanism by which the binding of antibodies to HVR1 blocks the binding and activity of broadly neutralizing antibodies to HCV. Immunization strategies that avoid the induction of HVR1 antibodies should increase the inhibitory activity of broadly neutralizing anti-HCV antibodies elicited by candidate vaccines.
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Identification of a Human Respiratory Syncytial Virus Cell Entry Inhibitor by Using a Novel Lentiviral Pseudotype System [Virus-Cell Interactions]
Lentiviral budding is governed by group-specific antigens (Gag proteins) and proceeds in the absence of cognate viral envelope proteins, which has been exploited to create pseudotypes incorporating envelope proteins from nonlentiviral families. Here, we report the generation of infectious lentiviral pseudoparticles incorporating human respiratory syncytial virus (hRSV) F protein alone (hRSV-Fpp) or carrying SH, G, and F proteins (hRSV-SH/G/Fpp). These particles recapitulate key infection steps of authentic hRSV particles, including utilization of glycosaminoglycans and low-pH-independent cell entry. Moreover, hRSV pseudoparticles (hRSVpp) can faithfully reproduce phenotypic resistance to a small-molecule fusion inhibitor in clinical development (BMS-433771) and a licensed therapeutic F protein-targeting antibody (palivizumab). Inoculation of several human cell lines from lung and liver revealed more than 30-fold differences in susceptibility to hRSVpp infection, suggesting differential expression of hRSV entry cofactors and/or restriction factors between these cell types. Moreover, we observed cell-type-dependent functional differences between hRSVpp carrying solely F protein or SH, G, and F proteins with regard to utilization of glycosaminoglycans. Using hRSVpp, we identified penta-O-galloyl-β-d-glucose (PGG) as a novel hRSV cell entry inhibitor. Moreover, we show that PGG also inhibits cell entry of hRSVpp carrying F proteins resistant to BMS-433771 or palivizumab. This work sheds new light on the mechanisms of hRSV cell entry, including possible strategies for antiviral intervention. Moreover, hRSVpp should prove valuable to dissect hRSV envelope protein functions, including the interaction with cell entry factors.
IMPORTANCE Lentiviral pseudotypes are highly useful to specifically dissect the functions of viral and host factors in cell entry, which have been exploited for numerous viruses. Here, we successfully created hRSVpp and show that they faithfully recapitulate key characteristics of parental hRSV cell entry. Importantly, hRSVpp accurately mirror hRSV resistance to small-molecule fusion inhibitors and clinically approved therapeutic antibodies. Moreover, we observed highly different susceptibilities of cell lines to hRSVpp infection and also differences between hRSVpp types (with F protein alone or with SH, G, and F proteins) in regard to cell entry. This indicates differential expression of host factors determining hRSV cell entry between these cell lines and highlights the fact that the hRSVpp system is useful to explore the functional properties of hRSV envelope protein combinations. Therefore, this system will be highly useful to study hRSV cell entry and host factor usage and to explore antiviral strategies targeting hRSV cell entry.
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Chaperone-Assisted Protein Folding Is Critical for Yellow Fever Virus NS3/4A Cleavage and Replication [Genome Replication and Regulation of Viral Gene Expression]
DNAJC14, a heat shock protein 40 (Hsp40) cochaperone, assists with Hsp70-mediated protein folding. Overexpressed DNAJC14 is targeted to sites of yellow fever virus (YFV) replication complex (RC) formation, where it interacts with viral nonstructural (NS) proteins and inhibits viral RNA replication. How RCs are assembled and the roles of chaperones in this coordinated process are largely unknown. We hypothesized that chaperones are diverted from their normal cellular protein quality control function to play similar roles during viral infection. Here, we show that DNAJC14 overexpression affects YFV polyprotein processing and alters RC assembly. We monitored YFV NS2A-5 polyprotein processing by the viral NS2B-3 protease in DNAJC14-overexpressing cells. Notably, DNAJC14 mutants that did not inhibit YFV replication had minimal effects on polyprotein processing, while overexpressed wild-type DNAJC14 affected the NS3/4A and NS4A/2K cleavage sites, resulting in altered NS3-to-NS3-4A ratios. This suggests that DNAJC14's folding activity normally modulates NS3/4A/2K cleavage events to liberate appropriate levels of NS3 and NS4A and promote RC formation. We introduced amino acid substitutions at the NS3/4A site to alter the levels of the NS3 and NS4A products and examined their effects on YFV replication. Residues with reduced cleavage efficiency did not support viral RNA replication, and only revertant viruses with a restored wild-type arginine or lysine residue at the NS3/4A site were obtained. We conclude that DNAJC14 inhibition of RC formation upon DNAJC14 overexpression is likely due to chaperone dysregulation and that YFV probably utilizes DNAJC14's cochaperone function to modulate processing at the NS3/4A site as a mechanism ensuring virus replication.
IMPORTANCE Flaviviruses are single-stranded RNA viruses that cause a wide range of illnesses. Upon host cell entry, the viral genome is translated on endoplasmic reticulum (ER) membranes to produce a single polyprotein, which is cleaved by host and viral proteases to generate viral proteins required for genome replication and virion production. Several studies suggest a role for molecular chaperones during these processes. While the details of chaperone roles have been elusive, in this report we show that overexpression of the ER-resident cochaperone DNAJC14 affects YFV polyprotein processing at the NS3/4A site. This work reveals that DNAJC14 modulation of NS3/4A site processing is an important mechanism to ensure virus replication. Our work highlights the importance of finely regulating flavivirus polyprotein processing. In addition, it suggests future studies to address similarities and/or differences among flaviviruses and to interrogate the precise mechanisms employed for polyprotein processing, a critical step that can ultimately be targeted for novel drug development.
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Tumor Suppressor Interferon-Regulatory Factor 1 Counteracts the Germinal Center Reaction Driven by a Cancer-Associated Gammaherpesvirus [Pathogenesis and Immunity]
Gammaherpesviruses are ubiquitous pathogens that are associated with the development of B cell lymphomas. Gammaherpesviruses employ multiple mechanisms to transiently stimulate a broad, polyclonal germinal center reaction, an inherently mutagenic stage of B cell differentiation that is thought to be the primary target of malignant transformation in virus-driven lymphomagenesis. We found that this gammaherpesvirus-driven germinal center expansion was exaggerated and lost its transient nature in the absence of interferon-regulatory factor 1 (IRF-1), a transcription factor with antiviral and tumor suppressor functions. Uncontrolled and persistent expansion of germinal center B cells led to pathological changes in the spleens of chronically infected IRF-1-deficient animals. Additionally, we found decreased IRF-1 expression in cases of human posttransplant lymphoproliferative disorder, a malignant condition associated with gammaherpesvirus infection. The results of our study define an unappreciated role for IRF-1 in B cell biology and provide insight into the potential mechanism of gammaherpesvirus-driven lymphomagenesis.
IMPORTANCE Gammaherpesviruses establish lifelong infection in most adults and are associated with B cell lymphomas. While the infection is asymptomatic in many hosts, it is critical to identify individuals who may be at an increased risk of virus-induced cancer. Such identification is currently impossible, as the host risk factors that predispose individuals toward viral lymphomagenesis are poorly understood. The current study identifies interferon-regulatory factor 1 (IRF-1) to be one of such candidate host factors. Specifically, we found that IRF-1 enforces long-term suppression of an inherently mutagenic stage of B cell differentiation that gammaherpesviruses are thought to target for transformation. Correspondingly, in the absence of IRF-1, chronic gammaherpesvirus infection induced pathological changes in the spleens of infected animals. Further, we found decreased IRF-1 expression in human gammaherpesvirus-induced B cell malignancies.
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Plasmacytoid Dendritic Cells Require Direct Infection To Sustain the Pulmonary Influenza A Virus-Specific CD8 T Cell Response [Cellular Response to Infection]
Following influenza A virus (IAV) infection, development of a robust IAV-specific CD8 T cell response is required for clearance of primary infection and enhances memory protection. Following IAV infection, plasmacytoid dendritic cells (pDC) or CD8α+ DC regulate pulmonary effector CD8 T cell responses within the lung. Without this DC-T cell interaction, insufficient effector CD8 T cells are maintained in the lungs, leading to enhanced morbidity and mortality. Previous studies have demonstrated that pDC are capable of classical presentation or cross-presentation of IAV antigens and could potentially regulate IAV-specific CD8 T cell responses through either mechanism. Our results demonstrate that pDC from the lungs of donor mice infected with an IAV that is not able to replicate in hematopoietic cells (142t-IAV), unlike donor pDC isolated from the lungs of control infected mice, are not able to rescue the host IAV-specific CD8 T cell response from apoptosis. This indicates that pDC must utilize the direct presentation pathway for this rescue. This inability of pDC from 142t-IAV donors to rescue the IAV-specific CD8 T cell response is not due to differences in the overall ability of 142t-IAV to replicate within the lungs or generate defective viral genomes or to differences in levels of costimulatory molecules required for this interaction. We further demonstrate that bypassing the antigen presentation pathway by coating the 142t-IAV pDC with IAV peptide epitopes restores their ability to rescue the IAV-specific CD8 T cell response.
IMPORTANCE IAV continues to be a global health burden, infecting 5 to 20% of the global population annually. Continued investigation into the mechanisms that mediate protective immune responses against IAV is important to improving current vaccination and antiviral strategies antagonistic toward IAV. Our findings presented herein demonstrate a key requirement for pDC promotion of effector CD8 T cell survival: that rather than utilizing cross-presentation, pDC must be infected and utilize the endogenous pathway for presentation of antigens to CD8 T cells during in vivo IAV infections. This suggests that targeting presentation via the endogenous pathway in pDC could be important for the development of unique antiviral cellular therapies.
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New Mechanism of Hepatic Fibrogenesis: Hepatitis C Virus Infection Induces Transforming Growth Factor {beta}1 Production through Glucose-Regulated Protein 94 [Pathogenesis and Immunity]
Hepatitis C virus (HCV) is one of the leading causes of chronic liver inflammatory disease (hepatitis), which often leads to more severe diseases, such as liver fibrosis, cirrhosis, and hepatocellular carcinoma. Liver fibrosis, in particular, is a major pathogenic consequence of HCV infection, and transforming growth factor β1 (TGF-β1) plays a key role in its pathogenesis. Several HCV proteins have been suggested to either augment or suppress the expression of TGF-β1 by HCV-infected cells. Here, we report that TGF-β1 levels are elevated in HCV-infected hepatocytes cultured in vitro and in liver tissue of HCV patients. Notably, the level of TGF-β1 in media from in vitro-cultured HCV-infected hepatocytes was high enough to activate primary hepatic stellate cells isolated from rats. This indicates that TGF-β1 secreted by HCV-infected hepatocytes is likely to play a key role in the liver fibrosis observed in HCV patients. Moreover, we showed that HCV E2 protein triggers the production of TGF-β1 by HCV-infected cells through overproduction of glucose-regulated protein 94 (GRP94).
IMPORTANCE Hepatic fibrosis is a critical step in liver cirrhosis caused by hepatitis C virus infection. It is already known that immune cells, including Kupffer cells, mediate liver fibrosis. Recently, several papers have suggested that HCV-infected hepatocytes also significantly produce TGF-β1. Here, we provide the first examination of TGF-β1 levels in the hepatocytes of HCV patients. Using an HCV culture system, we showed that HCV infection increases TGF-β1 production in hepatocytes. Furthermore, we confirmed that the amount of TGF-β1 secreted by HCV-infected hepatocytes was sufficient to activate primary hepatic stellate cells. To understand the molecular basis of TGF-β1 production in HCV-infected hepatocytes, we used HCV replicons and various stable cell lines. Finally, we elucidated that HCV E2 triggered TGF-β1 secretion via GRP94 mediated NF-B activation. This study contributes to the understanding of liver fibrosis by HCV and suggests a new potential target (GRP94) for blocking liver cirrhosis in HCV patients.
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Characterization of the Localized Immune Response in the Respiratory Tract of Ferrets following Infection with Influenza A and B Viruses [Pathogenesis and Immunity]
The burden of infection with seasonal influenza viruses is significant. Each year is typically characterized by the dominance of one (sub)type or lineage of influenza A or B virus, respectively. The incidence of disease varies annually, and while this may be attributed to a particular virus strain or subtype, the impacts of prior immunity, population differences, and variations in clinical assessment are also important. To improve our understanding of the impacts of seasonal influenza viruses, we directly compared clinical symptoms, virus shedding, and expression of cytokines, chemokines, and immune mediators in the upper respiratory tract (URT) of ferrets infected with contemporary A(H1N1)pdm09, A(H3N2), or influenza B virus. Gene expression in the lower respiratory tract (LRT) was also assessed. Clinical symptoms were minimal. Overall cytokine/chemokine profiles in the URT were consistent in pattern and magnitude between animals infected with influenza A and B viruses, and peak expression levels of interleukin-1α (IL-1α), IL-1β, IL-6, IL-12p40, alpha interferon (IFN-α), IFN-β, and tumor necrosis factor alpha (TNF-α) mRNAs correlated with peak levels of viral shedding. MCP1 and IFN- were expressed after the virus peak. Granzymes A and B and IL-10 reached peak expression as the virus was cleared and seroconversion was detected. Cytokine/chemokine gene expression in the LRT following A(H1N1)pdm09 virus infection reflected the observations seen for the URT but was delayed 2 or 3 days, as was virus replication. These data indicate that disease severities and localized immune responses following infection with seasonal influenza A and B viruses are similar, suggesting that other factors are likely to modulate the incidence and impact of seasonal influenza.
IMPORTANCE Both influenza A and B viruses cocirculate in the human population, and annual influenza seasons are typically dominated by an influenza A virus subtype or an influenza B virus lineage. Surveillance data indicate that the burden of disease is higher in some seasons, yet it is unclear whether this is due to specific virus strains or to other factors, such as cross-reactive immunity or clinical definitions of influenza. We directly compared disease severities and localized inflammatory responses to different seasonal influenza virus strains, including the 2009 pandemic strain, in healthy naive ferrets. We found that the disease severities and the cytokine and chemokine responses were similar irrespective of the seasonal strain or the location of the infection in the respiratory tract. This suggests that factors other than the immune response to a particular virus (sub)type contribute to the variable impact of influenza virus infection in a population.
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The Synthetic Antiviral Drug Arbidol Inhibits Globally Prevalent Pathogenic Viruses [Vaccines and Antiviral Agents]
Arbidol (ARB) is a synthetic antiviral originally developed to combat influenza viruses. ARB is currently used clinically in several countries but not in North America. We have previously shown that ARB inhibits in vitro hepatitis C virus (HCV) by blocking HCV entry and replication. In this report, we expand the list of viruses that are inhibited by ARB and demonstrate that ARB suppresses in vitro infection of mammalian cells with Ebola virus (EBOV), Tacaribe arenavirus, and human herpesvirus 8 (HHV-8). We also confirm suppression of hepatitis B virus and poliovirus by ARB. ARB inhibited EBOV Zaire Kikwit infection when added before or at the same time as virus infection and was less effective when added 24 h after EBOV infection. Experiments with recombinant vesicular stomatitis virus (VSV) expressing the EBOV Zaire glycoprotein showed that infection was inhibited by ARB at early stages, most likely at the level of viral entry into host cells. ARB inhibited HHV-8 replication to a similar degree as cidofovir. Our data broaden the spectrum of antiviral efficacy of ARB to include globally prevalent viruses that cause significant morbidity and mortality.
IMPORTANCE There are many globally prevalent viruses for which there are no licensed vaccines or antiviral medicines. Some of these viruses, such as Ebola virus or members of the arenavirus family, rapidly cause severe hemorrhagic diseases that can be fatal. Other viruses, such as hepatitis B virus or human herpesvirus 8 (HHV-8), establish persistent infections that cause chronic illnesses, including cancer. Thus, finding an affordable, effective, and safe drug that blocks many viruses remains an unmet medical need. The antiviral drug arbidol (ARB), already in clinical use in several countries as an anti-influenza treatment, has been previously shown to suppress the growth of many viruses. In this report, we expand the list of viruses that are blocked by ARB in a laboratory setting to include Ebola virus, Tacaribe arenavirus, and HHV-8, and we propose ARB as a broad-spectrum antiviral drug that may be useful against hemorrhagic viruses.
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Αλέξανδρος Γ. Σφακιανάκης Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,0030693260717...
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heory of COVID-19 pathogenesis Publication date: November 2020Source: Medical Hypotheses, Volume 144Author(s): Yuichiro J. Suzuki ScienceD...
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