Browsing by Author "Elankumaran, Subbiah"
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- Expression and activity of the urokinase plasminogen activator system in canine primary brain tumorsRossmeisl, John H. Jr.; Hall-Manning, Kelli; King, Jamie N.; Davalos, Rafael V.; Debinski, Waldemar; Elankumaran, Subbiah (Dove Press, 2017-04-12)Background: The expression of the urokinase plasminogen activator receptor (uPAR), a glycosylphosphatidylinositol-anchored protein family member, and the activity of its ligand, urokinase-type plasminogen activator (uPA), have been associated with the invasive and metastatic potentials of a variety of human brain tumors through their regulation of extracellular matrix degradation. Domesticated dogs develop naturally occurring brain tumors that share many clinical, phenotypic, molecular, and genetic features with their human counterparts, which has prompted the use of the dogs with spontaneous brain tumors as models to expedite the translation of novel brain tumor therapeutics to humans. There is currently little known regarding the role of the uPA system in canine brain tumorigenesis. The objective of this study was to characterize the expression of uPAR and the activity of uPA in canine brain tumors as justification for the development of uPAR-targeted brain tumor therapeutics in dogs. Methods: We investigated the expression of uPAR in 37 primary canine brain tumors using immunohistochemistry, Western blotting, real-time quantitative polymerase chain reaction analyses, and by the assay of the activity of uPA using casein–plasminogen zymography. Results: Expression of uPAR was observed in multiple tumoral microenvironmental niches, including neoplastic cells, stroma, and the vasculature of canine brain tumors. Relative to normal brain tissues, uPAR protein and mRNA expression were significantly greater in canine meningiomas, gliomas, and choroid plexus tumors. Increased activity of uPA was documented in all tumor types. Conclusions: uPAR is overexpressed and uPA activity increased in canine meningiomas, gliomas, and choroid plexus tumors. This study illustrates the potential of uPAR/uPA molecularly targeted approaches for canine brain tumor therapeutics and reinforces the translational significance of canines with spontaneous brain tumors as models for human disease.
- Genotypic and Pathotypic Characterization of Newcastle Disease Viruses from IndiaTirumurugaan, Krishnaswamy G.; Kapgate, Sunil; Vinupriya, Manavalan K.; Vijayarani, Kumanan; Kumanan, Kathaperumal; Elankumaran, Subbiah (PLOS, 2011-12-09)Newcastle disease virus (NDV) is an avian paramyxovirus that causes significant economic losses to the poultry industry in most parts of the world. The susceptibility of a wide variety of avian species coupled with synanthropic bird reservoirs has contributed to the vast genomic diversity of this virus as well as diagnostic failures. Since the first panzootic in 1926, Newcastle disease (ND) became enzootic in India with recurrent outbreaks in multiple avian species. The genetic characteristics of circulating strains in India, however, are largely unknown. To understand the nature of NDV genotypes in India, we characterized two representative strains isolated 13 years apart from a chicken and a pigeon by complete genome sequence analysis and pathotyping. The viruses were characterized as velogenic by pathogenicity indices devised to distinguish these strains. The genome length was 15,186 nucleotides (nt) and consisted of six non-overlapping genes, with conserved and complementary 3′ leader and 5′ trailer regions, conserved gene starts, gene stops, and intergenic sequences similar to those in avian paramyxovirus 1 (APMV-1) strains. Matrix gene sequence analysis grouped the pigeon isolate with APMV-1 strains. Phylogeny based on the fusion (F), and hemagglutinin (HN) genes and complete genome sequence grouped these viruses into genotype IV. Genotype IV strains are considered to have “died out” after the first panzootic (1926–1960) of ND. But, our results suggest that there is persistence of genotype IV strains in India.
- The Mechanistic Influence of Aligned Nanofiber Networks on Cell Shape, Migration and Blebbing Dynamics of Glioma CellsSharma, Puja; Sheets, Kevin; Elankumaran, Subbiah; Nain, Amrinder S. (The Royal Society of Chemistry, 2013-06-03)Investigating the mechanistic influence of the tumor microenvironment on cancer cell migration and membrane blebbing is crucial in the understanding and eventual arrest of cancer metastasis. In this study, we investigate the effect of suspended and aligned nanofibers on the glioma cytoskeleton, cell shape, migration and plasma membrane blebbing dynamics using a non-electrospinning fiber-manufacturing platform. Cells attached in repeatable shapes of spindle on single fibers, rectangular on two parallel fibers and polygonal on intersecting fibers. Structural stiffness (N m_1) of aligned and suspended nanofibers (average diameter: 400 nm, length: 4, 6, and 10 mm) was found to significantly alter the migration speed with higher migration on lower stiffness fibers. For cells attached to fibers and exhibiting blebbing, an increase in cellular spread area resulted in both reduced bleb count and bleb size with an overall increase in cell migration speed. Blebs no longer appeared past a critical cellular spread area of approximately 1400 _m2. Our results highlighting the influence of the mechanistic environment on the invasion dynamics of glioma cells add to the understanding of how biophysical components influence glioma cell migration and blebbing dynamics.
- A Novel Pathogenic Mammalian Orthoreovirus from Diarrheic Pigs and Swine Blood Meal in the United StatesNarayanappa, Athmaram Thimmasandra; Sooryanarain, Harini; Deventhiran, Jagadeeswaran; Cao, Dianjun; Venkatachalam, Backiyalakshmi Ammayappan; Kambiranda, Devaiah; LeRoith, Tanya; Heffron, C. Lynn; Lindstrom, Nicole; Hall, Karen; Jobst, Peter; Sexton, Cary; Meng, Xiang-Jin; Elankumaran, Subbiah (American Society for Microbiology, 2015-05)Since May 2013, outbreaks of porcine epidemic diarrhea have devastated the U.S. swine industry, causing immense economic losses. Two different swine enteric coronaviruses (porcine epidemic diarrhea virus and Delta coronavirus) have been isolated from the affected swine population. The disease has been reported from at least 32 states of the United States and other countries, including Mexico, Peru, Dominican Republic, Canada, Columbia, Ecuador, and Ukraine, with repeated outbreaks in previously infected herds. Here we report the isolation and characterization of a novel mammalian orthoreovirus 3 (MRV3) from diarrheic feces of piglets from these outbreaks in three states and ring-dried swine blood meal from multiple sources. MRV3 could not be isolated from healthy or pigs that had recovered from epidemic diarrhea from four states. Several MRV3 isolates were obtained from chloroform-extracted pig feces or blood meal in cell cultures or developing chicken embryos. Biological characterization of two representative isolates revealed trypsin resistance and thermostability at 90 degrees C. NextGen sequencing of ultrapurified viruses indicated a strong homology of the S1 segment to mammalian and bat MRV3. Neonatal piglets experimentally infected with these viruses or a chloroform extract of swine blood meal developed severe diarrhea and acute gastroenteritis with 100% mortality within 3 days postinfection. Therefore, the novel porcine MRV3 may contribute to enteric disease along with other swine enteric viruses. The role of MRV3 in the current outbreaks of porcine epidemic diarrhea in the United States remains to be determined, but the pathogenic nature of the virus warrants further investigations on its epidemiology and prevalence. IMPORTANCE Porcine orthoreoviruses causing diarrhea have been reported in China and Korea but not in the United States. We have isolated and characterized two pathogenic reassortant MRV3 isolates from swine fecal samples from porcine epidemic diarrhea outbreaks and ring-dried swine blood meal in the United States. These fecal and blood meal isolates or a chloroform extract of blood meal induced severe diarrhea and mortality in experimentally infected neonatal pigs. Genetic and phylogenetic analyses of two MRV3 isolates revealed that they are identical but differed significantly from nonpathogenic mammalian orthoreoviruses circulating in the United States. The present study provides a platform for immediate development of suitable vaccines and diagnostics to prevent and control porcine orthoreovirus diarrhea.
- Phase I/II Trial of Urokinase Plasminogen Activator-Targeted Oncolytic Newcastle Disease Virus for Canine Intracranial TumorsRossmeisl, John H. Jr.; King, Jamie N.; Robertson, John L.; Weger-Lucarelli, James; Elankumaran, Subbiah (MDPI, 2024-01-29)Neurotropic oncolytic viruses are appealing agents to treat brain tumors as they penetrate the blood–brain barrier and induce preferential cytolysis of neoplastic cells. The pathobiological similarities between human and canine brain tumors make immunocompetent dogs with naturally occurring tumors attractive models for the study of oncolytic virotherapies. In this dose-escalation/expansion study, an engineered Lasota NDV strain targeting the urokinase plasminogen activator system (rLAS-uPA) was administered by repetitive intravenous infusions to 20 dogs with intracranial tumors with the objectives of characterizing toxicities, immunologic responses, and neuroradiological anti-tumor effects of the virus for up to 6 months following treatment. Dose-limiting toxicities manifested as fever, hematologic, and neurological adverse events, and the maximum tolerated dose (MTD) of rLAS-uPA was 2 × 107 pfu/mL. Mild adverse events, including transient infusion reactions, diarrhea, and fever were observed in 16/18 of dogs treated at or below MTD. No infectious virus was recoverable from body fluids. Neutralizing antibodies to rLAS-uPA were present in all dogs by 2 weeks post-treatment, and viral genetic material was detected in post-treatment tumors from six dogs. Tumor volumetric reductions occurred in 2/11 dogs receiving the MTD. Systemically administered rLAS-uPA NDV was safe and induced anti-tumor effects in canine brain tumors, although modifications to evade host anti-viral immunity are needed to optimize this novel therapy.
- Relationship between Humidity and Influenza A Viability in Droplets and Implications for Influenza's SeasonalityYang, Wan; Elankumaran, Subbiah; Marr, Linsey C. (PLOS, 2012-10-03)Humidity has been associated with influenza’s seasonality, but the mechanisms underlying the relationship remain unclear. There is no consistent explanation for influenza’s transmission patterns that applies to both temperate and tropical regions. This study aimed to determine the relationship between ambient humidity and viability of the influenza A virus (IAV) during transmission between hosts and to explain the mechanisms underlying it. We measured the viability of IAV in droplets consisting of various model media, chosen to isolate effects of salts and proteins found in respiratory fluid, and in human mucus, at relative humidities (RH) ranging from 17% to 100%. In all media and mucus, viability was highest when RH was either close to 100% or below ,50%. When RH decreased from 84% to 50%, the relationship between viability and RH depended on droplet composition: viability decreased in saline solutions, did not change significantly in solutions supplemented with proteins, and increased dramatically in mucus. Additionally, viral decay increased linearly with salt concentration in saline solutions but not when they were supplemented with proteins. There appear to be three regimes of IAV viability in droplets, defined by humidity: physiological conditions (,100% RH) with high viability, concentrated conditions (50% to near 100% RH) with lower viability depending on the composition of media, and dry conditions (,50% RH) with high viability. This paradigm could help resolve conflicting findings in the literature on the relationship between IAV viability in aerosols and humidity, and results in human mucus could help explain influenza’s seasonality in different regions.
- A Time Course for Susceptibility to Staphylococcus aureus Respiratory Infection during Influenza in a Swine Model.Smith, E. A.; Kumar, S. R.; Deventhiran, Jagadeeswaran; Cecere, Thomas E.; LeRoith, Tanya; McGilliard, M.; Elankumaran, Subbiah; Mullarky, Isis K. (2011)Bacterial superinfections following influenza A virus (IAV) are predominant causes of morbidity in humans. The recent emergence of methicillin-resistant Staphylococcus aureus (MRSA) and highly virulent IAV strains has reduced treatment options. Development of an appropriate animal model to study secondary S. aureus infections may provide important information regarding disease pathogenesis. Pigs are natural hosts to both IAV and S. aureus and have respiratory physiology and immune response comparable to humans. To establish a time course of susceptibility to S. aureus after IAV infection, nursery pigs infected intranasally with IAV were challenged with MRSA at different time points. Lung pathology scores and MRSA CFU were evaluated in dual-infected animals after IAV infection. Flow cytometric analysis of bronchoalveolar lavage fluid indicated differences between treatments. These results demonstrate the appropriateness of an intranasal challenge model in nursery pigs for studying the pathogenesis of IAV and S. aureus coinfection and provide insights into the timeframe for susceptibility of IAV-infected pigs to secondary S. aureus infection.
- Toll-Like Receptor Responses to Peste des petits ruminants Virus in Goats and Water BuffaloDhanasekaran, Sakthivel; Biswas, Moanaro; Vignesh, Ambothi R.; Ramya, R.; Raj, Gopal Dhinakar; Tirumurugaan, Krishnaswamy G.; Raja, Angamuthu; Kataria, Ranjit S.; Parida, Satya; Elankumaran, Subbiah (Public Library of Science, 2014-11-04)Ovine rinderpest or goat plague is an economically important and contagious viral disease of sheep and goats, caused by the Peste des petits ruminants virus (PPRV). Differences in susceptibility to goat plague among different breeds and water buffalo exist. The host innate immune system discriminates between pathogen associated molecular patterns and self antigens through surveillance receptors known as Toll like receptors (TLR). We investigated the role of TLR and cytokines in differential susceptibility of goat breeds and water buffalo to PPRV. We examined the replication of PPRV in peripheral blood mononuclear cells (PBMC) of Indian domestic goats and water buffalo and demonstrated that the levels of TLR3 and TLR7 and downstream signaling molecules correlation with susceptibility vs resistance. Naturally susceptible goat breeds, Barbari and Tellichery, had dampened innate immune responses to PPRV and increased viral loads with lower basal expression levels of TLR 3/7. Upon stimulation of PBMC with synthetic TLR3 and TLR7 agonists or PPRV, the levels of proinflammatory cytokines were found to be significantly higher while immunosuppressive interleukin (IL) 10 levels were lower in PPRV resistant Kanni and Salem Black breeds and water buffalo at transcriptional level, correlating with reduced viral loads in infected PBMC. Water buffalo produced higher levels of interferon (IFN) α in comparison with goats at transcriptional and translational levels. Pre-treatment of Vero cells with human IFNα resulted in reduction of PPRV replication, confirming the role of IFNα in limiting PPRV replication. Treatment with IRS66, a TLR7 antagonist, resulted in the reduction of IFNα levels, with increased PPRV replication confirming the role of TLR7. Single nucleotide polymorphism analysis of TLR7 of these goat breeds did not show any marked nucleotide differences that might account for susceptibility vs resistance to PPRV. Analyzing other host genetic factors might provide further insights on susceptibility to PPRV and genetic polymorphisms in the host.
- Toxicity of Particulate Matter from Incineration of NanowasteVejerano, Eric P.; Ma, Yanjun; Holder, Amara L.; Pruden, Amy; Elankumaran, Subbiah; Marr, Linsey C. (The Royal Society of Chemistry, 2015-01-13)Disposal of some nanomaterial-containing waste by incineration and the subsequent formation of particulate matter (PM) along with hazardous combustion by-products are inevitable. The effect of nanomaterials on the toxicity of the PM is unknown. We assessed the oxidative potential (OP) and toxicity of PM resulting from the incineration of pure nanomaterials and of paper and plastic wastes containing Ag, NiO, TiO2, ceria, C60, Fe2O3, or CdSe/ZnS quantum dots (CdSe QD) at mass loadings ranging from 0.1 wt% to 10 wt%. We measured reactive oxygen species (ROS) using the dichlorofluorescein assay, and we also measured consumption of ascorbic acid, dithiothreitol (DTT), glutathione (GSH), or uric acid antioxidants from raw and solvent-extracted PM, denoted “cleaned PM”. We determined cytotoxicity and genotoxicity of PM to A549 human lung epithelial cells with the WST-1 cell viability and histone immunofluorescence assays, respectively. In most cases, the presence of nanomaterials in the waste did not significantly affect the OP of PM; however, PM derived from waste containing Ag, TiO2, and C60 had elevated ROS response in the GSH and DTT assays. The ratio of reduced to oxidized glutathione was significantly higher for cleaned PM compared to raw PM for almost all nanomaterials at almost all concentrations, indicating that combustion by-products adsorbed on raw PM play an important role in determining OP. The presence of nanomaterials did not significantly modify the cytotoxicity or genotoxicity of the PM. Different antioxidants used to assess OP had varying sensitivity towards organic compounds v. metals in PM. The presence of these seven nanomaterials at low concentrations in the waste stream is not expected to exacerbate the hazard posed by PM that is produced by incineration.