ABSTRACT
We engineered and produced an ion channel blocking peptibody, that targets the acetylcholine-activated inwardly rectifying potassium current (IKACh). Peptibodies are chimeric proteins generated by fusing a biologically active peptide with the fragment crystallizable (Fc) region of the human immunoglobulin G (IgG). The IKACh blocking peptibody was engineered as a fusion between the human IgG1 Fc fragment and the IKACh inhibitor tertiapinQ (TP), a 21-amino acid synthetic peptidotoxin, originally isolated from the European honey bee venom. The peptibody was purified from the culture supernatant of human embryonic kidney (HEK) cells transfected with the peptibody construct. We tested the hypothesis that the bioengineered peptibody is bioactive and a potent blocker of IKACh. In HEK cells transfected with Kir3.1 and Kir3.4, the molecular correlates of IKACh, patch clamp showed that the peptibody was ~300-fold more potent than TP. Molecular dynamics simulations suggested that the increased potency could be due to an increased stabilization of the complex formed by peptibody-Kir3.1/3.4 channels compared to tertiapin-Kir3.1/3.4 channels. In isolated mouse myocytes, the peptibody blocked carbachol (Cch)-activated IKACh in atrial cells but did not affect the potassium inwardly rectifying background current in ventricular myocytes. In anesthetized mice, the peptibody abrogated the bradycardic effects of intraperitoneal Cch injection. Moreover, in aged mice, the peptibody reduced the inducibility of atrial fibrillation, likely via blocking constitutively active IKACh. Bioengineered anti-ion channel peptibodies can be powerful and highly potent ion channel blockers, with the potential to guide the development of modulators of ion channels or antiarrhythmic modalities.
Subject(s)
Potassium , Humans , Animals , Bees , MiceABSTRACT
Respiratory syncytial virus (RSV) is a highly contagious human pathogen that poses a significant threat to children under the age of two, and there is a current need for new small molecule treatments. The Antarctic sponge Suberites sp. is a known source of sesterterpenes, and following an NMR-guided fractionation procedure, it was found to produce several previously unreported metabolites. Neosuberitenone (1), with a new carbon scaffold herein termed the 'neosuberitane' backbone, six suberitenone derivatives (2-7), an ansellane-type terpenoid (8), and a highly degraded sesterterpene (9), as well as previously reported suberitenones A (10) and B (11), were characterized. The structures of all of the isolated metabolites including absolute configurations are proposed on the basis of NMR, HRESIMS, optical rotation, and XRD data. The biological activities of the metabolites were evaluated in a range of infectious disease assays. Suberitenones A, B, and F (3) were found to be active against RSV, though, along with other Suberites sp. metabolites, they were inactive in bacterial and fungal screens. None of the metabolites were cytotoxic for J774 macrophages or A549 adenocarcinoma cells. The selectivity of suberitenones A, B, and F for RSV among other infectious agents is noteworthy.
Subject(s)
Porifera , Suberites , Animals , Child , Humans , Respiratory Syncytial Viruses , Antarctic Regions , Terpenes/chemistry , Sesterterpenes/chemistryABSTRACT
Respiratory syncytial virus (RSV) is a single-stranded, negative-sense RNA virus in the family Pneumoviridae and genus Orthopneumovirus that can cause severe disease in infants, immunocompromised adults, and the elderly. The RSV viral RNA-dependent RNA polymerase (vRdRp) complex is composed of the phosphoprotein (P) and the large polymerase protein (L). The P protein is constitutively phosphorylated by host kinases and has 41 serine (S) and threonine (T) residues as potential phosphorylation sites. To identify important phosphorylation residues in the P protein, we systematically and individually mutated all S and T residues to alanine (A) and analyzed their effects on genome transcription and replication by using a minigenome system. We found that the mutation of eight residues resulted in minigenome activity significantly lower than that of wild-type (WT) P. We then incorporated these mutations (T210A, S203A, T151A, S156A, T160A, S23A, T188A, and T105A) into full-length genome cDNA to rescue recombinant RSV. We were able to recover four recombinant viruses (with T151A, S156A, T160A, or S23A), suggesting that RSV-P residues T210, S203, T188, and T105 are essential for viral RNA replication. Among the four recombinant viruses rescued, rRSV-T160A caused a minor growth defect relative to its parental virus while rRSV-S156A had severely restricted replication due to decreased levels of genomic RNA. During infection, P-S156A phosphorylation was decreased, and when passaged, the S156A virus acquired a known compensatory mutation in L (L795I) that enhanced both WT-P and P-S156A minigenome activity and was able to partially rescue the S156A viral growth defect. This work demonstrates that residues T210, S203, T188, and T105 are critical for RSV replication and that S156 plays a critical role in viral RNA synthesis. IMPORTANCE RSV-P is a heavily phosphorylated protein that is required for RSV replication. In this study, we identified several residues, including P-S156, as phosphorylation sites that play critical roles in efficient viral growth and genome replication. Future studies to identify the specific kinase(s) that phosphorylates these residues can lead to kinase inhibitors and antiviral drugs for this important human pathogen.
Subject(s)
Genome, Viral , Phosphoproteins/genetics , Phosphoproteins/metabolism , Respiratory Syncytial Virus, Human/chemistry , Respiratory Syncytial Virus, Human/genetics , Transcription, Genetic , Virus Replication , Animals , Chlorocebus aethiops , Phosphoproteins/classification , RNA, Viral/genetics , Vero Cells , Viral Proteins/genetics , Viral Proteins/metabolismABSTRACT
Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infections in children of <5 years of age worldwide, infecting the majority of infants in their first year of life. Despite the widespread impact of this virus, no vaccine is currently available. For more than 50 years, live attenuated vaccines (LAVs) have been shown to protect against other childhood viral infections, offering the advantage of presenting all viral proteins to the immune system for stimulation of both B and T cell responses and memory. The RSV LAV candidate described here, rgRSV-L(G1857A)-G(L208A), contains two modifications: an attenuating mutation in the S-adenosylmethionine (SAM) binding site of the viral mRNA cap methyltransferase (MTase) within the large (L) polymerase protein and a mutation in the attachment (G) glycoprotein that inhibits its cleavage during production in Vero cells, resulting in virus with a "noncleaved G" (ncG). RSV virions containing the ncG have an increased ability to infect primary well-differentiated human bronchial epithelial (HBE) cultures which model the in vivo site of immunization, the ciliated airway epithelium. This RSV LAV candidate is produced efficiently in Vero cells, is highly attenuated in HBE cultures, efficiently induces neutralizing antibodies that are long lasting, and provides protection against an RSV challenge in the cotton rat, without causing enhanced disease. Similar results were obtained in a rhesus macaque.IMPORTANCE Globally, respiratory syncytial virus (RSV) is a major cause of death in children under 1 year of age, yet no vaccine is available. We have generated a novel RSV live attenuated vaccine candidate containing mutations in the L and G proteins. The L polymerase mutation does not inhibit virus yield in Vero cells, the cell type required for vaccine production, but greatly reduces virus spread in human bronchial epithelial (HBE) cultures, a logical in vitro predictor of in vivo attenuation. The G attachment protein mutation reduces its cleavage in Vero cells, thereby increasing vaccine virus yield, making vaccine production more economical. In cotton rats, this RSV vaccine candidate is highly attenuated at a dose of 105 PFU and completely protective following immunization with 500 PFU, 200-fold less than the dose usually used in such studies. It also induced long-lasting antibodies in cotton rats and protected a rhesus macaque from RSV challenge. This mutant virus is an excellent RSV live attenuated vaccine candidate.
Subject(s)
Mutation , Respiratory Syncytial Virus Infections/prevention & control , Respiratory Syncytial Virus Vaccines/administration & dosage , Respiratory Syncytial Virus, Human/immunology , S-Adenosylmethionine/metabolism , Viral Envelope Proteins/metabolism , Virus Replication , Animals , Binding Sites , Female , Humans , Macaca mulatta , Male , Respiratory Syncytial Virus Infections/immunology , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus Vaccines/immunology , Respiratory Syncytial Virus, Human/drug effects , Sigmodontinae , Vaccination , Viral Envelope Proteins/genetics , Viral Proteins/genetics , Viral Proteins/metabolismABSTRACT
Respiratory syncytial virus (RSV) is a major cause of respiratory infections in infants and the elderly. Although the RSV matrix (M) protein has key roles in the nucleus early in infection, and in the cytoplasm later, the molecular basis of switching between the nuclear and cytoplasmic compartments is not known. Here, we show that protein kinase CK2 can regulate M nucleocytoplasmic distribution, whereby inhibition of CK2 using the specific inhibitor 4,5,6,7-tetrabromobenzo-triazole (TBB) increases M nuclear accumulation in infected cells as well as when ectopically expressed in transfected cells. We use truncation/mutagenic analysis for the first time to show that serine (S) 95 and threonine (T) 205 are key CK2 sites that regulate M nuclear localization. Dual alanine (A)-substitution to prevent phosphorylation abolished TBB- enhancement of nuclear accumulation, while aspartic acid (D) substitution to mimic phosphorylation at S95 increased nuclear accumulation. D95 also induced cytoplasmic aggregate formation, implying that a negative charge at S95 may modulate M oligomerization. A95/205 substitution in recombinant RSV resulted in reduced virus production compared with wild type, with D95/205 substitution resulting in an even greater level of attenuation. Our data support a model where unphosphorylated M is imported into the nucleus, followed by phosphorylation of T205 and S95 later in infection to facilitate nuclear export and cytoplasmic retention of M, respectively, as well as oligomerization/virus budding. In the absence of widely available, efficacious treatments to protect against RSV, the results raise the possibility of antiviral strategies targeted at CK2.
Subject(s)
Respiratory Syncytial Virus, Human , Active Transport, Cell Nucleus , Aged , Cell Nucleus/metabolism , Cytoplasm/metabolism , Humans , PhosphorylationABSTRACT
BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), can be detected in respiratory samples by real-time reverse transcriptase polymerase chain reaction (RT-PCR) or other molecular methods. Accessibility of diagnostic testing for COVID-19 has been limited by intermittent shortages of supplies required for testing, including flocked nasopharyngeal (FLNP) swabs. METHODS: We developed a 3-dimensional printed nasopharyngeal (3DP) swab as a replacement of the FLNP swab. The performance of 3DP and FLNP swabs were compared in a clinical trial of symptomatic patients at 3 clinical sites (nĆ¢ĀĀ =Ć¢ĀĀ 291) using 3 SARS-CoV-2 emergency use authorization tests: a modified version of the Centers for Disease Control and Prevention (CDC) RT-PCR Diagnostic Panel and 2 commercial automated formats, Roche Cobas and NeuMoDx. RESULTS: The cycle threshold-C(t)-values from the gene targets and the RNase P gene control in the CDC assay showed no significant differences between swabs for both gene targets (PĆ¢ĀĀ =Ć¢ĀĀ .152 and PĆ¢ĀĀ =Ć¢ĀĀ .092), with the RNase P target performing significantly better in the 3DP swabs (PĆ¢ĀĀ <Ć¢ĀĀ .001). The C(t) values showed no significant differences between swabs for both viral gene targets in the Roche cobas assay (PĆ¢ĀĀ =Ć¢ĀĀ .05 and PĆ¢ĀĀ =Ć¢ĀĀ .05) as well as the NeuMoDx assay (PĆ¢ĀĀ =Ć¢ĀĀ .401 and PĆ¢ĀĀ =Ć¢ĀĀ .484). The overall clinical correlation of COVID-19 diagnosis between all methods was 95.88% (Kappa 0.901). CONCLUSIONS: The 3DP swabs were equivalent to standard FLNP in 3 testing platforms for SARS-CoV-2. Given the need for widespread testing, 3DP swabs printed onsite are an alternate to FLNP that can rapidly scale in response to acute needs when supply chain disruptions affect availability of collection kits.
Subject(s)
COVID-19 Testing , COVID-19 , Humans , Nasopharynx , Printing, Three-Dimensional , SARS-CoV-2 , Specimen HandlingABSTRACT
INTRODUCTION: There is a need for a cost-effective method to identify individuals with a high risk of osteoporosis. This study aimed to investigate the suitability of hand grip strength in predicting the risk of osteoporosis in Asian adults. MATERIALS AND METHODS: In this cross-sectional, hospital-based study of 1007 participants, the bone mineral density of the spine and hips was evaluated using dual-energy X-ray absorptiometry according to the 2019 International Society for Clinical Densitometry official positions. Bone microarchitecture was evaluated using the trabecular bone score, and hand grip strength was measured in the dominant hand using a hand digital dynamometer. RESULTS: Hand grip strength was significantly related to bone density and bone microarchitecture. Moreover, hand grip strength was a significant predictor of osteoporosis in both women and men. For osteoporosis prediction in women, a threshold of 21.9Ā kg of hand grip strength had a sensitivity of 59%, specificity of 59%, and area under the curve (AUC) of 0.61. In men, a threshold of 28.7Ā kg had a sensitivity of 66%, specificity of 78%, and AUC of 0.75. The optimal cutoff strengths for osteoporosis depended on age and sex. CONCLUSION: The measurement of hand grip strength is a simple, cost-effective and an easy assessment method for identifying individuals at aĀ high risk ofĀ osteoporosis. The cutoff strength for evaluating osteoporosis in adults is age and sex specific.
Subject(s)
Asian People , Hand Strength/physiology , Osteoporosis/diagnosis , Osteoporosis/physiopathology , Absorptiometry, Photon , Adult , Aged , Bone Density , Cancellous Bone/pathology , Cancellous Bone/physiopathology , Cross-Sectional Studies , Female , Humans , Linear Models , Male , Middle Aged , Multivariate Analysis , Osteoporosis/diagnostic imaging , Risk FactorsABSTRACT
Osteosarcopenia, the coexistence of bone and muscle loss, is common in older adults, but its definition lacks international consensus. This cross-sectional study (n = 1199 post-menopausal women) aimed to determine the association between osteosarcopenia and fragility fractures and to investigate the impact of the definition of the "osteo" component. Bone mineral density and bone microarchitecture were measured by dual-energy X-ray absorptiometry and the trabecular bone score (TBS), respectively. The "osteo" component of osteosarcopenia was classified as osteoporosis (T-score ≤ -2.5 SD), osteopenia/osteoporosis (T-score < -1 SD), and high-fracture-risk osteopenia (-2.5 SD < T-score < -1 SD)/osteoporosis (T-score ≤ -2.5 SD). The Fracture Risk Assessment Tool was used to identify high-fracture-risk osteopenia. Altogether, 30.3%, 32.2%, 14.4%, and 23.1% of participants had osteosarcopenia, osteoporosis alone, sarcopenia alone, and neither condition, respectively. The odds ratios between osteosarcopenia and fragility fractures were 3.70 (95% CI: 1.94-7.04) for osteosarcopenia, 2.48 (95% CI: 1.30-4.71) for osteoporosis alone, and 1.87 (95% CI: 0.84-4.14) for sarcopenia alone. Women with osteosarcopenia also had lower TBS, indicating worse bone microarchitecture. In conclusion, women with osteosarcopenia were more likely to have previously sustained a fracture compared to those without osteosarcopenia, with sarcopenia alone, and with osteoporosis alone. The relationship between osteosarcopenia and fracture risk may be best identified when considering high-fracture-risk osteopenia and osteoporosis.
Subject(s)
Bone Diseases, Metabolic/physiopathology , Sarcopenia/physiopathology , Absorptiometry, Photon , Aged , Bone Density/physiology , Bone Diseases, Metabolic/metabolism , Bone and Bones/pathology , Cancellous Bone , Cross-Sectional Studies , Female , Fractures, Bone/etiology , Fractures, Bone/metabolism , Humans , Middle Aged , Osteoporosis/physiopathology , Postmenopause , Sarcopenia/complications , Sarcopenia/metabolism , Spinal FracturesABSTRACT
Zika virus (ZIKV) is a flavivirus that is primarily transmitted by Aedes aegypti, the mosquito vector also important in transmission of the flaviviruses responsible for dengue fever, yellow fever, and chikungunya. Because of occurrence in the same geographic regions, serologic cross-reactivity, and similar but often less severe clinical manifestations, such as dengue and chikungunya infections, ZIKV infection likely has gone undetected, misdiagnosed, or both for many years. ZIKV is somewhat unique among flaviviruses in its ability to also be transmitted through sexual contact, nonsexual body fluids, and perinatally. The relatively recent detection of the link between ZIKV infection and Guillain-BarrƩ syndrome and fetal neurological defects, including microcephaly, has prompted intense efforts aimed at the development of new and specific diagnostic tests. Infection with ZIKV has been postulated to lead to a more severe clinical course from other structurally related viruses, especially dengue, and vice versa because of a phenomenon termed antibody-dependent enhancement. Inactivated whole virus, DNA, RNA, and vectored vaccine approaches to prevent ZIKV infection are in development, as are treatments for active disease that are safe in pregnant women. Here we summarize the important epidemiologic and clinical features of ZIKV infection, as well as the progress and challenges in developing rapid point-of-care diagnostic tests and vaccines to prevent disease. We used electronic databases to identify relevant published data regarding ZIKV MeSH searches.
Subject(s)
Communicable Diseases, Emerging , Microcephaly , Zika Virus Infection , Zika Virus , Communicable Diseases, Emerging/epidemiology , Communicable Diseases, Emerging/immunology , Communicable Diseases, Emerging/prevention & control , Communicable Diseases, Emerging/transmission , Guillain-Barre Syndrome/epidemiology , Guillain-Barre Syndrome/immunology , Guillain-Barre Syndrome/prevention & control , Guillain-Barre Syndrome/virology , Humans , Microcephaly/epidemiology , Microcephaly/immunology , Microcephaly/prevention & control , Microcephaly/virology , Zika Virus/immunology , Zika Virus/pathogenicity , Zika Virus Infection/epidemiology , Zika Virus Infection/immunology , Zika Virus Infection/prevention & control , Zika Virus Infection/transmissionABSTRACT
Here we report a gain in function for mutant (mt) superoxide dismutase I (SOD1), a cause of familial amyotrophic lateral sclerosis (FALS), wherein small soluble oligomers of mtSOD1 acquire a membrane toxicity. Phosphatidylglycerol (PG) lipid domains are selectively targeted, which could result in membrane damage or "toxic channels" becoming active in the bilayer. This PG-selective SOD1-mediated membrane toxicity is largely reversible in vitro by a widely-available FDA-approved surfactant and membrane-stabilizer P188. Treatment of G93ASOD1 transgenic mice with P188 significantly delayed symptoms onset, extended survival and decreased motoneuron death. The use of P188 or an analogue, which targets mtSOD1 misfolding-induced membrane toxicity, may provide a new direction for ALS treatment.
Subject(s)
Amyotrophic Lateral Sclerosis/drug therapy , Amyotrophic Lateral Sclerosis/genetics , Cell Membrane/physiology , Mutation/physiology , Poloxamer/therapeutic use , Superoxide Dismutase-1/genetics , Amyotrophic Lateral Sclerosis/pathology , Animals , Cell Membrane/drug effects , Cell Membrane/pathology , Humans , Male , Mice , Mice, Transgenic , Mutation/drug effects , Poloxamer/pharmacology , Surface-Active Agents/pharmacology , Surface-Active Agents/therapeutic useABSTRACT
UNLABELLED: Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infection in young children worldwide. The RSV nonstructural protein 2 (NS2) is a multifunctional protein that primarily acts to antagonize the innate immune system by targeting STAT2 for proteasomal degradation. We investigated the structural determinants of NS2 important for interaction with the host ubiquitin system to degrade STAT2 during infection. We found that NS2 expression enhances ubiquitination of host proteins. Bioinformatics analysis provided a platform for identification of specific residues that limit NS2-induced ubiquitination. Combinations of multiple mutations displayed an additive effect on reducing NS2-induced ubiquitination. Using a reverse genetics system, we generated recombinant RSV (rRSV) containing NS2 ubiquitin mutations, which maintained their effect on ubiquitin expression during infection. Interestingly, STAT2 degradation activity was ablated in the NS2 ubiquitin mutant rRSV. In addition, NS2 ubiquitin mutations decreased rRSV replication, indicating a correlation between NS2's ubiquitin function and antagonism of innate immune signaling to enhance viral replication. Our approach of targeting NS2 residues required for NS2 inhibition of immune responses provides a mechanism for attenuating RSV for vaccine development. IMPORTANCE: RSV has been circulating globally for more than 60 years, causing severe respiratory disease in pediatric, elderly, and immunocompromised populations. Production of a safe, effective vaccine against RSV is a public health priority. The NS2 protein is an effective target for prevention and treatment of RSV due to its antagonistic activity against the innate immune system. However, NS2-deleted RSV vaccine candidates rendered RSV overattenuated or poorly immunogenic. Alternatively, we can modify essential NS2 structural features to marginally limit viral growth while maintaining immune responses, providing the necessary balance between antigenicity and safety required for an effective vaccine. We coupled bioinformatics analysis with reverse genetics to introduce mutations into RSV's negative-sense genome. In this way we constructed rRSV NS2 ubiquitin mutants that limited NS2's ability to antagonize the innate immune system, thereby attenuating rRSV growth and increasing innate immune responses.
Subject(s)
Immunity, Innate/immunology , Respiratory Syncytial Virus Infections/immunology , Respiratory Syncytial Virus, Human/immunology , STAT2 Transcription Factor/metabolism , Ubiquitin/metabolism , Viral Nonstructural Proteins/metabolism , Virus Replication/immunology , A549 Cells , Amino Acid Sequence , Animals , Chlorocebus aethiops , Humans , Mutagenesis, Site-Directed , Mutation/genetics , Respiratory Syncytial Virus Infections/genetics , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/genetics , STAT2 Transcription Factor/genetics , Sequence Homology, Amino Acid , Signal Transduction , Ubiquitination , Vero Cells , Viral Load , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/geneticsABSTRACT
Respiratory syncytial virus (RSV) is the most frequent cause of lower respiratory disease in infants, but no vaccine or effective therapy is available. The initiation of RSV infection of immortalized cells is largely dependent on cell surface heparan sulfate (HS), a receptor for the RSV attachment (G) glycoprotein in immortalized cells. However, RSV infects the ciliated cells in primary well differentiated human airway epithelial (HAE) cultures via the apical surface, but HS is not detectable on this surface. Here we show that soluble HS inhibits infection of immortalized cells, but not HAE cultures, confirming that HS is not the receptor on HAE cultures. Conversely, a "non-neutralizing" monoclonal antibody against the G protein that does not block RSV infection of immortalized cells, does inhibit infection of HAE cultures. This antibody was previously shown to block the interaction between the G protein and the chemokine receptor CX3CR1 and we have mapped the binding site for this antibody to the CX3C motif and its surrounding region in the G protein. We show that CX3CR1 is present on the apical surface of ciliated cells in HAE cultures and especially on the cilia. RSV infection of HAE cultures is reduced by an antibody against CX3CR1 and by mutations in the G protein CX3C motif. Additionally, mice lacking CX3CR1 are less susceptible to RSV infection. These findings demonstrate that RSV uses CX3CR1 as a cellular receptor on HAE cultures and highlight the importance of using a physiologically relevant model to study virus entry and antibody neutralization.
Subject(s)
Host-Parasite Interactions/physiology , Receptors, Chemokine/metabolism , Respiratory Mucosa/virology , Respiratory Syncytial Virus Infections/metabolism , Respiratory Syncytial Virus, Human/metabolism , Animals , CX3C Chemokine Receptor 1 , Cell Line , Cells, Cultured , GTP-Binding Proteins/metabolism , Humans , Immunohistochemistry , Mice , Mice, Inbred C57BL , Transfection , Viral Proteins/metabolism , Virus InternalizationABSTRACT
UNLABELLED: Airway epithelium is the primary target of many respiratory viruses. However, virus induction and antagonism of host responses by human airway epithelium remains poorly understood. To address this, we developed a model of respiratory syncytial virus (RSV) infection based on well-differentiated pediatric primary bronchial epithelial cell cultures (WD-PBECs) that mimics hallmarks of RSV disease in infants. RSV is the most important respiratory viral pathogen in young infants worldwide. We found that RSV induces a potent antiviral state in WD-PBECs that was mediated in part by secreted factors, including interferon lambda 1 (IFN-λ1)/interleukin-29 (IL-29). In contrast, type I IFNs were not detected following RSV infection of WD-PBECs. IFN responses in RSV-infected WD-PBECs reflected those in lower airway samples from RSV-hospitalized infants. In view of the prominence of IL-29, we determined whether recombinant IL-29 treatment of WD-PBECs before or after infection abrogated RSV replication. Interestingly, IL-29 demonstrated prophylactic, but not therapeutic, potential against RSV. The absence of therapeutic potential reflected effective RSV antagonism of IFN-mediated antiviral responses in infected cells. Our data are consistent with RSV nonstructural proteins 1 and/or 2 perturbing the Jak-STAT signaling pathway, with concomitant reduced expression of antiviral effector molecules, such as MxA/B. Antagonism of Jak-STAT signaling was restricted to RSV-infected cells in WD-PBEC cultures. Importantly, our study provides the rationale to further explore IL-29 as a novel RSV prophylactic. IMPORTANCE: Most respiratory viruses target airway epithelium for infection and replication, which is central to causing disease. However, for most human viruses we have a poor understanding of their interactions with human airway epithelium. Respiratory syncytial virus (RSV) is the most important viral pathogen of young infants. To help understand RSV interactions with pediatric airway epithelium, we previously developed three-dimensional primary cell cultures from infant bronchial epithelium that reproduce several hallmarks of RSV infection in infants, indicating that they represent authentic surrogates of RSV infection in infants. We found that RSV induced a potent antiviral state in these cultures and that a type III interferon, interleukin IL-29 (IL-29), was involved. Indeed, our data suggest that IL-29 has potential to prevent RSV disease. However, we also demonstrated that RSV efficiently circumvents this antiviral immune response and identified mechanisms by which this may occur. Our study provides new insights into RSV interaction with pediatric airway epithelium.
Subject(s)
Interleukins/pharmacology , Respiratory Mucosa/immunology , Respiratory Syncytial Virus Infections/immunology , Respiratory Syncytial Virus, Human/immunology , Animals , Chlorocebus aethiops , Humans , Infant , Interferons , Interleukins/immunology , Janus Kinases/immunology , Myxovirus Resistance Proteins/immunology , Respiratory Mucosa/pathology , Respiratory Mucosa/virology , Respiratory Syncytial Virus Infections/pathology , Respiratory Syncytial Virus Infections/prevention & control , STAT Transcription Factors/immunology , Signal Transduction/drug effects , Signal Transduction/immunology , Vero CellsABSTRACT
Human respiratory syncytial virus (RSV) is a major health challenge in the young and elderly owing to the lack of a safe and effective vaccine and proven antiviral drugs. Understanding the mechanisms by which viral genes and proteins modulate the host response to infection is critical for identifying novel disease intervention strategies. In this study, the RSV non-structural protein NS1 was shown to suppress miR-24 expression during infection. Lack of NS1 was linked to increased expression of miR-24, whilst NS1 overexpression suppressed miR-24 expression. NS1 was found to induce Kruppel-like factor 6 (KLF6), a transcription factor that positively regulates the transforming growth factor (TGF)-b pathway to induce cell cycle arrest. Silencing of KLF6 led to increased miR-24 expression via downregulation of TGF-Ć. Treatment with exogenous TGF-Ć suppressed miR-24 expression and induced KLF6. Confocal microscopy showed co-localization of KLF6 and RSV NS1. These findings indicated that RSV NS1 interacts with KLF6 and modulates miR-24 expression and TGF-Ć, which facilitates RSV replication.
Subject(s)
MicroRNAs/genetics , Respiratory Syncytial Virus Infections/genetics , Respiratory Syncytial Virus, Human/metabolism , Transforming Growth Factor beta/metabolism , Viral Nonstructural Proteins/metabolism , Host-Pathogen Interactions , Humans , Kruppel-Like Factor 6 , Kruppel-Like Transcription Factors/genetics , Kruppel-Like Transcription Factors/metabolism , MicroRNAs/metabolism , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins/metabolism , Respiratory Syncytial Virus Infections/metabolism , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/genetics , Viral Nonstructural Proteins/geneticsABSTRACT
Respiratory syncytial virus (RSV) is a negative-sense single-stranded RNA virus responsible for lower respiratory tract infections. During infection, the presence of double-stranded RNA (dsRNA) activates the interferon (IFN) regulatory factor 3 (IRF3) transcription factor, an event triggering expression of immediate early, IFN-stimulated genes (ISGs). We examine the role of transcriptional elongation in control of IRF3-dependent ISG expression. RSV infection induces ISG54, ISG56, and CIG5 gene expression in an IRF3-dependent manner demonstrated by IRF3 small interfering RNA (siRNA) silencing in both A549 epithelial cells and IRF3(-/-) MEFs. ISG expression was mediated by the recruitment of IRF3, CDK9, polymerase II (Pol II), and phospho-Ser(2) carboxy-terminal domain (CTD) Pol II to the IFN-stimulated response element (ISRE) binding sites of the IRF3-dependent ISG promoters in native chromatin. We find that RSV infection enhances the activated fraction of cyclin-dependent kinase 9 (CDK9) by promoting its association with bromodomain 4 (BRD4) and disrupting its association with the inhibitory 7SK small nuclear RNA. The requirement of CDK9 activity for ISG expression was shown by siRNA-mediated silencing of CDK9 and by a selective CDK9 inhibitor in A549 cells. In contrast, RSV-induced beta interferon (IFN-Ć) expression is not influenced by CDK9 inhibition. Using transcript-selective quantitative real-time reverse transcription-PCR (Q-RT-PCR) assays for the ISG54 gene, we observed that RSV induces transition from short to fully spliced mRNA transcripts and that this transition is blocked by CDK9 inhibition in both A549 and primary human small airway epithelial cells. These data indicate that transcription elongation plays a major role in RSV-induced ISG expression and is mediated by IRF3-dependent recruitment of activated CDK9. CDK9 activity may be a target for immunomodulation in RSV-induced lung disease.
Subject(s)
Cyclin-Dependent Kinase 9/metabolism , Epithelial Cells/virology , Interferon Regulatory Factor-3/metabolism , Interferons/metabolism , Lung/virology , Respiratory Syncytial Virus Infections/immunology , Respiratory Syncytial Virus, Human/pathogenicity , Transcription Factors/metabolism , Adaptor Proteins, Signal Transducing , Cell Line , Chromatin Immunoprecipitation , Epithelial Cells/immunology , Epithelial Cells/metabolism , Humans , Immunity, Innate , Interferon Regulatory Factor-3/genetics , Lung/cytology , Lung/immunology , RNA-Binding Proteins , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/immunology , Transcription Factors/geneticsABSTRACT
OBJECTIVE: The objective of our study was to evaluate the CT characteristics of globe rupture. MATERIALS AND METHODS: The medical records of patients seen in the emergency department with blunt, penetrating, or explosive orbit injury were retrospectively reviewed. A total of 75 patients (76 injured globes) were included (56 males and 19 females; average age, 45.1 years; age range, 5-95 years). CT examinations were reviewed by two experienced radiologists without knowledge of ophthalmologic findings, original orbital CT images, or surgical outcomes. RESULTS: Of the 76 globe injuries, 33 (43%) were ruptured and 43 (57%) were nonruptured. There were significant differences between the ruptured and nonruptured globes with respect to intraocular hemorrhage, lens dislocation and destruction, an intraocular foreign body, intraocular gas, anterior chamber depth (ACD), and globe deformity and wall irregularity (p < 0.05). There was good interrater agreement between the two radiologists (kappa value range, 0.63-0.96). The average sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of CT for the detection of globe rupture based on readings by two radiologists were 76%, 85%, 80%, 82%, and 81%, respectively. CONCLUSION: Although CT is extremely useful in the evaluation of ocular trauma, it should not be solely relied on for the diagnosis of globe rupture because of the potentially catastrophic consequences of an undiagnosed injury. A difference in ACD can be diagnostic of globe rupture.
Subject(s)
Eye Injuries/diagnostic imaging , Tomography, X-Ray Computed , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Retrospective Studies , Rupture , Young AdultABSTRACT
BACKGROUND: The angioarchitecture of arteriovenous fistulas (AVFs) of cerebral arteriovenous malformation (CAVM) after stereotactic radiosurgery (SRS) remain unclear. The purpose of this study is to report the angiographic change of AVF components of CAVMs after SRS and outcomes of endovascular embolisation. METHODS: From 2002 to 2012, a total of 523 CAVMs had been treated primarily by SRS with more than 3-year latency. Among these databases, there were 19 patients with 21 AVFs undergoing embolization after SRS. We retrospectively analyzed the angioarchitecture of the CAVM to identify AVFs, morphologic change and outcomes of AVFs after SRS and embolisation. RESULTS: Eight AVFs were in the periphery of CAVMs, the other 13 were in a central location. Eighteen of 21 AVFs remained constant in morphology after SRS, while three feeders of AVFs were associated with radiation arteritis. The causes of failure to identify AVFs before SRS were overlooked (n = 7) or there was superimposition with feeders, nidus and/or venous drains of CAVMs (n = 14). Total fistula occlusion was achieved in all 21 AVFs; residual CAVMs was totally obliterated by embolisation and/or additional SRS in 12 patients. One patient had a small procedure-related intracerebral hemorrhage. Mean follow-up period was 26 months. CONCLUSIONS: Early detection of AVF components of CAVMs prior to SRS may be difficult, particularly those in a central location. However, most AVFs became evident and showed consistency in angiographic morphology after obliteration of the majority nidus parts of CAVMs. Endovascular embolisation is effective in managing these AVF components.
Subject(s)
Arteriovenous Fistula/therapy , Cerebral Hemorrhage/surgery , Embolization, Therapeutic , Intracranial Arteriovenous Malformations/therapy , Adult , Aged , Arteriovenous Fistula/epidemiology , Arteriovenous Fistula/pathology , Cerebral Angiography/methods , Cerebral Hemorrhage/pathology , Cerebral Hemorrhage/radiotherapy , Embolization, Therapeutic/methods , Female , Humans , Intracranial Arteriovenous Malformations/pathology , Male , Middle Aged , Retrospective Studies , Treatment OutcomeSubject(s)
Airway Remodeling/immunology , Asthma/pathology , Mast Cells/immunology , Plasminogen Activator Inhibitor 1/biosynthesis , Animals , Asthma/immunology , Asthma/metabolism , Disease Models, Animal , Inflammation/immunology , Inflammation/metabolism , Inflammation/pathology , Mast Cells/metabolism , Mice , Mice, Inbred C57BL , Plasminogen Activator Inhibitor 1/immunologyABSTRACT
General anesthesia induces a reversible loss of consciousness (LOC), a state that is characterized by the inability to feel pain. Identifying LOC in animals poses unique challenges, because the method most commonly used in humans, responding to questions, cannot be used in animals. For over a century, loss of righting reflex (LORR) has been used to assess LOC in animals. This is the only animal method that correlates directly with LOC in humans and has become the standard proxy measure used in research. However, the reporting of how LORR is assessed varies extensively. This systematic literature review examined the consistency and completeness of LORR methods used in rats and mice. The terms 'righting reflex,' 'anesthesia,' 'conscious,' 'rats,' 'mice,' and their derivatives were used to search 5 electronic databases. The abstracts of the 985 articles identified were screened for indications that the study assessed LORR in mice or rats. Full texts of selected articles were reviewed for LORR methodological completeness, with reported methods categorized by 1) animal placement method, 2) behavioral presence of righting reflex, 3) duration of LORR testing, 4) behavioral LORR, and 5) animal position for testing LORR. Only 22 papers reported on all 5 methodological categories. Of the 22 papers, 21 used unique LORR methodologies, with descriptions of LORR methods differing in at least one category as compared with all other studies. This variability indicates that even papers that included all 5 categories still had substantial differences in their methodological descriptions. These findings reveal substantial inconsistencies in LORR methodology and reporting in the biomedical literature likely compromising study replicability and data interpretation.