The Experts below are selected from a list of 1413 Experts worldwide ranked by ideXlab platform
Ken E Olson - One of the best experts on this subject based on the ideXlab platform.
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infection with mosquito borne alphavirus induces selective loss of dopaminergic neurons neuroinflammation and widespread protein aggregation
npj Parkinson's disease, 2019Co-Authors: Collin M Bantle, Aaron T Phillips, Ken E Olson, Richard J Smeyne, Savannah M Rocha, Ronald B TjalkensAbstract:Neuroinvasive infections with mosquito-borne alphaviruses such as Western Equine Encephalitis virus (WEEV) can cause post-encephalitic parkinsonism. To understand the mechanisms underlying these neurological effects, we examined the capacity of WEEV to induce progressive neurodegeneration in outbred CD-1 mice following non-lethal encephalitic infection. Animals were experientally infected with recombinant WEEV expressing firefly luciferase or dsRed (RFP) reporters and the extent of viral replication was controlled using passive immunotherapy. WEEV spread along the neuronal axis from the olfactory bulb to the entorhinal cortex, hippocampus and basal midbrain by 4 days post infection (DPI). Infection caused activation of microglia and astrocytes, selective loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and neurobehavioral abnormalities. After 8 weeks, surviving mice displayed continued loss of dopamine neurons in the SNpc, lingering glial cell activation and gene expression profiles consistent with a neurodegenerative phenotype. Strikingly, prominent proteinase K-resistant protein aggregates were present in the the entorhinal cortex, hippocampus and basal midbrain that stained positively for phospho-serine129 α-synuclein (SNCA). These results indicate that WEEV may cause lasting neurological deficits through a severe neuroinflammatory response promoting both neuronal injury and protein aggregation in surviving individuals.
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venezuelan and Western Equine Encephalitis virus e1 liposome antigen nucleic acid complexes protect mice from lethal challenge with multiple alphaviruses
Virology, 2016Co-Authors: Amber B Rico, Ann M. Powers, Aaron T Phillips, Tony Schountz, Donald L Jarvis, Ronald B Tjalkens, Ken E OlsonAbstract:Eastern, Venezuelan and Western Equine Encephalitis viruses (EEEV, VEEV, and WEEV) are mosquito-borne viruses that cause substantial disease in humans and other vertebrates. Vaccines are limited and current treatment options have not proven successful. In this report, we vaccinated outbred mice with lipid-antigen-nucleic acid-complexes (LANACs) containing VEEV E1+WEEV E1 antigen and characterized protective efficacy against lethal EEEV, VEEV, and WEEV challenge. Vaccination resulted in complete protection against EEEV, VEEV, and WEEV in CD-1 mice. Measurements of bioluminescence and plaque reduction neutralization tests (PRNTs) indicate that LANAC VEEV E1+WEEV E1 vaccination is sterilizing against VEEV and WEEV challenge; whereas immunity to EEEV is not sterilizing. Passive transfer of rabbit VEEV E1+WEEV E1 immune serum to naive mice extended the mean time to death (MTD) of EEEV challenged mice and provided significant protection from lethal VEEV and WEEV challenge.
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Molecular Determinants of Mouse Neurovirulence and Mosquito Infection for Western Equine Encephalitis Virus
2016Co-Authors: Eric C. Mossel, Jeremy P. Ledermann, Ann M. Powers, Aaron T Phillips, Erin M. Borl, Ken E OlsonAbstract:Western Equine Encephalitis virus (WEEV) is a naturally occurring recombinant virus derived from ancestral Sindbis and Eastern Equine Encephalitis viruses. We previously showed that infection by WEEV isolates McMillan (McM) and IMP-181 (IMP) results in high (,90–100%) and low (0%) mortality, respectively, in outbred CD-1 mice when virus is delivered by either subcutaneous or aerosol routes. However, relatively little is known about specific virulence determinants of WEEV. We previously observed that IMP infected Culex tarsalis mosquitoes at a high rate (app. 80%) following ingestion of an infected bloodmeal but these mosquitoes were infected by McM at a much lower rate (10%). To understand the viral role in these phenotypic differences, we characterized the pathogenic phenotypes of McM/IMP chimeras. Chimeras encoding the E2 of McM on an IMP backbone (or the reciprocal) had the most significant effect on infection phenotypes in mice or mosquitoes. Furthermore, exchanging the arginine, present on IMP E2 glycoprotein at position 214, for the glutamine present at the same position on McM, ablated mouse mortality. Curiously, the reciprocal exchange did not confer mouse virulence to the IMP virus. Mosquito infectivity was also determined and significantly, one of the important loci was the same as the mouse virulence determinant identified above. Replacing either IMP E2 amino acid 181 or 214 with the corresponding McM amino acid lowered mosquito infection rates to McM-like levels. As with the mouse neurovirulence, reciprocal exchange of amino acids did not confer mosquito infectivity. The identification of WEEV E2 amino acid 214 as necessary for both IMP mosquit
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entry sites of venezuelan and Western Equine Encephalitis viruses in the mouse central nervous system following peripheral infection
Journal of Virology, 2016Co-Authors: Aaron T Phillips, Amber B Rico, Ronald B Tjalkens, Charles B Stauft, Sean L Hammond, Tawfik A Aboellail, Ken E OlsonAbstract:ABSTRACT Venezuelan and Western Equine Encephalitis viruses (VEEV and WEEV; Alphavirus; Togaviridae) are mosquito-borne pathogens causing central nervous system (CNS) disease in humans and equids. Adult CD-1 mice also develop CNS disease after infection with VEEV and WEEV. Adult CD-1 mice infected by the intranasal (i.n.) route, showed that VEEV and WEEV enter the brain through olfactory sensory neurons (OSNs). In this study, we injected the mouse footpad with recombinant WEEV (McMillan) or VEEV (subtype IC strain 3908) expressing firefly luciferase (fLUC) to simulate mosquito infection and examined alphavirus entry in the CNS. Luciferase expression served as a marker of infection detected as bioluminescence (BLM) by in vivo and ex vivo imaging. BLM imaging detected WEEV and VEEV at 12 h postinoculation (hpi) at the injection site (footpad) and as early as 72 hpi in the brain. BLM from WEEV.McM-fLUC and VEEV.3908-fLUC injections was initially detected in the brain9s circumventricular organs (CVOs). No BLM activity was detected in the olfactory neuroepithelium or OSNs. Mice were also injected in the footpad with WEEV.McM expressing DsRed (Discosoma sp.) and imaged by confocal fluorescence microscopy. DsRed imaging supported our BLM findings by detecting WEEV in the CVOs prior to spreading along the neuronal axis to other brain regions. Taken together, these findings support our hypothesis that peripherally injected alphaviruses enter the CNS by hematogenous seeding of the CVOs followed by centripetal spread along the neuronal axis. IMPORTANCE VEEV and WEEV are mosquito-borne viruses causing sporadic epidemics in the Americas. Both viruses are associated with CNS disease in horses, humans, and mouse infection models. In this study, we injected VEEV or WEEV, engineered to express bioluminescent or fluorescent reporters (fLUC and DsRed, respectively), into the footpads of outbred CD-1 mice to simulate transmission by a mosquito. Reporter expression serves as detectable bioluminescent and fluorescent markers of VEEV and WEEV replication and infection. Bioluminescence imaging, histological examination, and confocal fluorescence microscopy were used to identify early entry sites of these alphaviruses in the CNS. We observed that specific areas of the brain (circumventricular organs [CVOs]) consistently showed the earliest signs of infection with VEEV and WEEV. Histological examination supported VEEV and WEEV entering the brain of mice at specific sites where the blood-brain barrier is naturally absent.
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alphavirus e1 glycoprotein liposome nucleic acid complexes protect mice from lethal challenge with multiple alphaviruses
New Horizons in Translational Medicine, 2015Co-Authors: Amber B Rico, Ann M. Powers, Aaron T Phillips, Tony Schountz, Ann M Toth, Donald L Jarvis, Ken E OlsonAbstract:Alphaviruses are globally distributed, mosquito borne pathogens that cause death and disease in vertebrates, including humans. Therapeutics to combat alphaviral disease are non-existant and only a handful of IND status vaccines are available. Of the available vaccines most are associated with a poor immunological response and a high rate of reactivity, and none protects against more than a single alphavirus species. We designed and tested novel alphavirus vaccines comprised of the E1 glycoproteins of Western Equine Encephalitis virus (WEEV) or Venezuelan Equine Encephalitis virus (VEEV). Immunization with cationic lipid nucleic acid complexes (CLNCs) and alphavirus E1ecto mixture (lipid-antigen-nucleic acid complexes:LANACs) provided significant protection in mice challenged with either WEEV, VEEV or eastern Equine Encephalitis virus (EEEV) regardless of challenge route. LANAC immunized mice mount a strong humoral immune response lacking neutralizing antibody. Passive transfer of immune sera from LANAC immunized mice to non-immunized mice confers protection to challenge, indicating that non-neutralizing antibody is sufficient for protection. In summary, our LANAC vaccine has both therapeutic and prophylactic potential and is able to offer protection against distinct alphavirus species irrespective of the route of infection.
Robert J. Meagher - One of the best experts on this subject based on the ideXlab platform.
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Surveillance for Western Equine Encephalitis, St. Louis Encephalitis, and West Nile Viruses Using Reverse Transcription Loop-Mediated Isothermal Amplification.
PLOS ONE, 2016Co-Authors: Sarah S. Wheeler, Cameron Ball, Stanley A. Langevin, Lark L. Coffey, Ying Fang, Robert J. MeagherAbstract:Collection of mosquitoes and testing for vector-borne viruses is a key surveillance activity that directly influences the vector control efforts of public health agencies, including determining when and where to apply insecticides. Vector control districts in California routinely monitor for three human pathogenic viruses including West Nile virus (WNV), Western Equine Encephalitis virus (WEEV), and St. Louis Encephalitis virus (SLEV). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) offers highly sensitive and specific detection of these three viruses in a single multiplex reaction, but this technique requires costly, specialized equipment that is generally only available in centralized public health laboratories. We report the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) to detect WNV, WEEV, and SLEV RNA extracted from pooled mosquito samples collected in California, including novel primer sets for specific detection of WEEV and SLEV, targeting the nonstructural protein 4 (nsP4) gene of WEEV and the 3’ untranslated region (3’-UTR) of SLEV. Our WEEV and SLEV RT-LAMP primers allowed detection of
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surveillance for Western Equine Encephalitis st louis Encephalitis and west nile viruses using reverse transcription loop mediated isothermal amplification
PLOS ONE, 2016Co-Authors: Sarah S. Wheeler, Cameron Ball, Stanley A. Langevin, Lark L. Coffey, Ying Fang, Robert J. MeagherAbstract:Collection of mosquitoes and testing for vector-borne viruses is a key surveillance activity that directly influences the vector control efforts of public health agencies, including determining when and where to apply insecticides. Vector control districts in California routinely monitor for three human pathogenic viruses including West Nile virus (WNV), Western Equine Encephalitis virus (WEEV), and St. Louis Encephalitis virus (SLEV). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) offers highly sensitive and specific detection of these three viruses in a single multiplex reaction, but this technique requires costly, specialized equipment that is generally only available in centralized public health laboratories. We report the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) to detect WNV, WEEV, and SLEV RNA extracted from pooled mosquito samples collected in California, including novel primer sets for specific detection of WEEV and SLEV, targeting the nonstructural protein 4 (nsP4) gene of WEEV and the 3’ untranslated region (3’-UTR) of SLEV. Our WEEV and SLEV RT-LAMP primers allowed detection of <0.1 PFU/reaction of their respective targets in <30 minutes, and exhibited high specificity without cross reactivity when tested against a panel of alphaviruses and flaviviruses. Furthermore, the SLEV primers do not cross-react with WNV, despite both viruses being closely related members of the Japanese Encephalitis virus complex. The SLEV and WEEV primers can also be combined in a single RT-LAMP reaction, with discrimination between amplicons by melt curve analysis. Although RT-qPCR is approximately one order of magnitude more sensitive than RT-LAMP for all three targets, the RT-LAMP technique is less instrumentally intensive than RT-qPCR and provides a more cost-effective method of vector-borne virus surveillance.
Aaron T Phillips - One of the best experts on this subject based on the ideXlab platform.
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infection with mosquito borne alphavirus induces selective loss of dopaminergic neurons neuroinflammation and widespread protein aggregation
npj Parkinson's disease, 2019Co-Authors: Collin M Bantle, Aaron T Phillips, Ken E Olson, Richard J Smeyne, Savannah M Rocha, Ronald B TjalkensAbstract:Neuroinvasive infections with mosquito-borne alphaviruses such as Western Equine Encephalitis virus (WEEV) can cause post-encephalitic parkinsonism. To understand the mechanisms underlying these neurological effects, we examined the capacity of WEEV to induce progressive neurodegeneration in outbred CD-1 mice following non-lethal encephalitic infection. Animals were experientally infected with recombinant WEEV expressing firefly luciferase or dsRed (RFP) reporters and the extent of viral replication was controlled using passive immunotherapy. WEEV spread along the neuronal axis from the olfactory bulb to the entorhinal cortex, hippocampus and basal midbrain by 4 days post infection (DPI). Infection caused activation of microglia and astrocytes, selective loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and neurobehavioral abnormalities. After 8 weeks, surviving mice displayed continued loss of dopamine neurons in the SNpc, lingering glial cell activation and gene expression profiles consistent with a neurodegenerative phenotype. Strikingly, prominent proteinase K-resistant protein aggregates were present in the the entorhinal cortex, hippocampus and basal midbrain that stained positively for phospho-serine129 α-synuclein (SNCA). These results indicate that WEEV may cause lasting neurological deficits through a severe neuroinflammatory response promoting both neuronal injury and protein aggregation in surviving individuals.
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venezuelan and Western Equine Encephalitis virus e1 liposome antigen nucleic acid complexes protect mice from lethal challenge with multiple alphaviruses
Virology, 2016Co-Authors: Amber B Rico, Ann M. Powers, Aaron T Phillips, Tony Schountz, Donald L Jarvis, Ronald B Tjalkens, Ken E OlsonAbstract:Eastern, Venezuelan and Western Equine Encephalitis viruses (EEEV, VEEV, and WEEV) are mosquito-borne viruses that cause substantial disease in humans and other vertebrates. Vaccines are limited and current treatment options have not proven successful. In this report, we vaccinated outbred mice with lipid-antigen-nucleic acid-complexes (LANACs) containing VEEV E1+WEEV E1 antigen and characterized protective efficacy against lethal EEEV, VEEV, and WEEV challenge. Vaccination resulted in complete protection against EEEV, VEEV, and WEEV in CD-1 mice. Measurements of bioluminescence and plaque reduction neutralization tests (PRNTs) indicate that LANAC VEEV E1+WEEV E1 vaccination is sterilizing against VEEV and WEEV challenge; whereas immunity to EEEV is not sterilizing. Passive transfer of rabbit VEEV E1+WEEV E1 immune serum to naive mice extended the mean time to death (MTD) of EEEV challenged mice and provided significant protection from lethal VEEV and WEEV challenge.
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Molecular Determinants of Mouse Neurovirulence and Mosquito Infection for Western Equine Encephalitis Virus
2016Co-Authors: Eric C. Mossel, Jeremy P. Ledermann, Ann M. Powers, Aaron T Phillips, Erin M. Borl, Ken E OlsonAbstract:Western Equine Encephalitis virus (WEEV) is a naturally occurring recombinant virus derived from ancestral Sindbis and Eastern Equine Encephalitis viruses. We previously showed that infection by WEEV isolates McMillan (McM) and IMP-181 (IMP) results in high (,90–100%) and low (0%) mortality, respectively, in outbred CD-1 mice when virus is delivered by either subcutaneous or aerosol routes. However, relatively little is known about specific virulence determinants of WEEV. We previously observed that IMP infected Culex tarsalis mosquitoes at a high rate (app. 80%) following ingestion of an infected bloodmeal but these mosquitoes were infected by McM at a much lower rate (10%). To understand the viral role in these phenotypic differences, we characterized the pathogenic phenotypes of McM/IMP chimeras. Chimeras encoding the E2 of McM on an IMP backbone (or the reciprocal) had the most significant effect on infection phenotypes in mice or mosquitoes. Furthermore, exchanging the arginine, present on IMP E2 glycoprotein at position 214, for the glutamine present at the same position on McM, ablated mouse mortality. Curiously, the reciprocal exchange did not confer mouse virulence to the IMP virus. Mosquito infectivity was also determined and significantly, one of the important loci was the same as the mouse virulence determinant identified above. Replacing either IMP E2 amino acid 181 or 214 with the corresponding McM amino acid lowered mosquito infection rates to McM-like levels. As with the mouse neurovirulence, reciprocal exchange of amino acids did not confer mosquito infectivity. The identification of WEEV E2 amino acid 214 as necessary for both IMP mosquit
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entry sites of venezuelan and Western Equine Encephalitis viruses in the mouse central nervous system following peripheral infection
Journal of Virology, 2016Co-Authors: Aaron T Phillips, Amber B Rico, Ronald B Tjalkens, Charles B Stauft, Sean L Hammond, Tawfik A Aboellail, Ken E OlsonAbstract:ABSTRACT Venezuelan and Western Equine Encephalitis viruses (VEEV and WEEV; Alphavirus; Togaviridae) are mosquito-borne pathogens causing central nervous system (CNS) disease in humans and equids. Adult CD-1 mice also develop CNS disease after infection with VEEV and WEEV. Adult CD-1 mice infected by the intranasal (i.n.) route, showed that VEEV and WEEV enter the brain through olfactory sensory neurons (OSNs). In this study, we injected the mouse footpad with recombinant WEEV (McMillan) or VEEV (subtype IC strain 3908) expressing firefly luciferase (fLUC) to simulate mosquito infection and examined alphavirus entry in the CNS. Luciferase expression served as a marker of infection detected as bioluminescence (BLM) by in vivo and ex vivo imaging. BLM imaging detected WEEV and VEEV at 12 h postinoculation (hpi) at the injection site (footpad) and as early as 72 hpi in the brain. BLM from WEEV.McM-fLUC and VEEV.3908-fLUC injections was initially detected in the brain9s circumventricular organs (CVOs). No BLM activity was detected in the olfactory neuroepithelium or OSNs. Mice were also injected in the footpad with WEEV.McM expressing DsRed (Discosoma sp.) and imaged by confocal fluorescence microscopy. DsRed imaging supported our BLM findings by detecting WEEV in the CVOs prior to spreading along the neuronal axis to other brain regions. Taken together, these findings support our hypothesis that peripherally injected alphaviruses enter the CNS by hematogenous seeding of the CVOs followed by centripetal spread along the neuronal axis. IMPORTANCE VEEV and WEEV are mosquito-borne viruses causing sporadic epidemics in the Americas. Both viruses are associated with CNS disease in horses, humans, and mouse infection models. In this study, we injected VEEV or WEEV, engineered to express bioluminescent or fluorescent reporters (fLUC and DsRed, respectively), into the footpads of outbred CD-1 mice to simulate transmission by a mosquito. Reporter expression serves as detectable bioluminescent and fluorescent markers of VEEV and WEEV replication and infection. Bioluminescence imaging, histological examination, and confocal fluorescence microscopy were used to identify early entry sites of these alphaviruses in the CNS. We observed that specific areas of the brain (circumventricular organs [CVOs]) consistently showed the earliest signs of infection with VEEV and WEEV. Histological examination supported VEEV and WEEV entering the brain of mice at specific sites where the blood-brain barrier is naturally absent.
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alphavirus e1 glycoprotein liposome nucleic acid complexes protect mice from lethal challenge with multiple alphaviruses
New Horizons in Translational Medicine, 2015Co-Authors: Amber B Rico, Ann M. Powers, Aaron T Phillips, Tony Schountz, Ann M Toth, Donald L Jarvis, Ken E OlsonAbstract:Alphaviruses are globally distributed, mosquito borne pathogens that cause death and disease in vertebrates, including humans. Therapeutics to combat alphaviral disease are non-existant and only a handful of IND status vaccines are available. Of the available vaccines most are associated with a poor immunological response and a high rate of reactivity, and none protects against more than a single alphavirus species. We designed and tested novel alphavirus vaccines comprised of the E1 glycoproteins of Western Equine Encephalitis virus (WEEV) or Venezuelan Equine Encephalitis virus (VEEV). Immunization with cationic lipid nucleic acid complexes (CLNCs) and alphavirus E1ecto mixture (lipid-antigen-nucleic acid complexes:LANACs) provided significant protection in mice challenged with either WEEV, VEEV or eastern Equine Encephalitis virus (EEEV) regardless of challenge route. LANAC immunized mice mount a strong humoral immune response lacking neutralizing antibody. Passive transfer of immune sera from LANAC immunized mice to non-immunized mice confers protection to challenge, indicating that non-neutralizing antibody is sufficient for protection. In summary, our LANAC vaccine has both therapeutic and prophylactic potential and is able to offer protection against distinct alphavirus species irrespective of the route of infection.
Sarah S. Wheeler - One of the best experts on this subject based on the ideXlab platform.
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Surveillance for Western Equine Encephalitis, St. Louis Encephalitis, and West Nile Viruses Using Reverse Transcription Loop-Mediated Isothermal Amplification.
PLOS ONE, 2016Co-Authors: Sarah S. Wheeler, Cameron Ball, Stanley A. Langevin, Lark L. Coffey, Ying Fang, Robert J. MeagherAbstract:Collection of mosquitoes and testing for vector-borne viruses is a key surveillance activity that directly influences the vector control efforts of public health agencies, including determining when and where to apply insecticides. Vector control districts in California routinely monitor for three human pathogenic viruses including West Nile virus (WNV), Western Equine Encephalitis virus (WEEV), and St. Louis Encephalitis virus (SLEV). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) offers highly sensitive and specific detection of these three viruses in a single multiplex reaction, but this technique requires costly, specialized equipment that is generally only available in centralized public health laboratories. We report the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) to detect WNV, WEEV, and SLEV RNA extracted from pooled mosquito samples collected in California, including novel primer sets for specific detection of WEEV and SLEV, targeting the nonstructural protein 4 (nsP4) gene of WEEV and the 3’ untranslated region (3’-UTR) of SLEV. Our WEEV and SLEV RT-LAMP primers allowed detection of
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surveillance for Western Equine Encephalitis st louis Encephalitis and west nile viruses using reverse transcription loop mediated isothermal amplification
PLOS ONE, 2016Co-Authors: Sarah S. Wheeler, Cameron Ball, Stanley A. Langevin, Lark L. Coffey, Ying Fang, Robert J. MeagherAbstract:Collection of mosquitoes and testing for vector-borne viruses is a key surveillance activity that directly influences the vector control efforts of public health agencies, including determining when and where to apply insecticides. Vector control districts in California routinely monitor for three human pathogenic viruses including West Nile virus (WNV), Western Equine Encephalitis virus (WEEV), and St. Louis Encephalitis virus (SLEV). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) offers highly sensitive and specific detection of these three viruses in a single multiplex reaction, but this technique requires costly, specialized equipment that is generally only available in centralized public health laboratories. We report the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) to detect WNV, WEEV, and SLEV RNA extracted from pooled mosquito samples collected in California, including novel primer sets for specific detection of WEEV and SLEV, targeting the nonstructural protein 4 (nsP4) gene of WEEV and the 3’ untranslated region (3’-UTR) of SLEV. Our WEEV and SLEV RT-LAMP primers allowed detection of <0.1 PFU/reaction of their respective targets in <30 minutes, and exhibited high specificity without cross reactivity when tested against a panel of alphaviruses and flaviviruses. Furthermore, the SLEV primers do not cross-react with WNV, despite both viruses being closely related members of the Japanese Encephalitis virus complex. The SLEV and WEEV primers can also be combined in a single RT-LAMP reaction, with discrimination between amplicons by melt curve analysis. Although RT-qPCR is approximately one order of magnitude more sensitive than RT-LAMP for all three targets, the RT-LAMP technique is less instrumentally intensive than RT-qPCR and provides a more cost-effective method of vector-borne virus surveillance.
Amber B Rico - One of the best experts on this subject based on the ideXlab platform.
-
venezuelan and Western Equine Encephalitis virus e1 liposome antigen nucleic acid complexes protect mice from lethal challenge with multiple alphaviruses
Virology, 2016Co-Authors: Amber B Rico, Ann M. Powers, Aaron T Phillips, Tony Schountz, Donald L Jarvis, Ronald B Tjalkens, Ken E OlsonAbstract:Eastern, Venezuelan and Western Equine Encephalitis viruses (EEEV, VEEV, and WEEV) are mosquito-borne viruses that cause substantial disease in humans and other vertebrates. Vaccines are limited and current treatment options have not proven successful. In this report, we vaccinated outbred mice with lipid-antigen-nucleic acid-complexes (LANACs) containing VEEV E1+WEEV E1 antigen and characterized protective efficacy against lethal EEEV, VEEV, and WEEV challenge. Vaccination resulted in complete protection against EEEV, VEEV, and WEEV in CD-1 mice. Measurements of bioluminescence and plaque reduction neutralization tests (PRNTs) indicate that LANAC VEEV E1+WEEV E1 vaccination is sterilizing against VEEV and WEEV challenge; whereas immunity to EEEV is not sterilizing. Passive transfer of rabbit VEEV E1+WEEV E1 immune serum to naive mice extended the mean time to death (MTD) of EEEV challenged mice and provided significant protection from lethal VEEV and WEEV challenge.
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entry sites of venezuelan and Western Equine Encephalitis viruses in the mouse central nervous system following peripheral infection
Journal of Virology, 2016Co-Authors: Aaron T Phillips, Amber B Rico, Ronald B Tjalkens, Charles B Stauft, Sean L Hammond, Tawfik A Aboellail, Ken E OlsonAbstract:ABSTRACT Venezuelan and Western Equine Encephalitis viruses (VEEV and WEEV; Alphavirus; Togaviridae) are mosquito-borne pathogens causing central nervous system (CNS) disease in humans and equids. Adult CD-1 mice also develop CNS disease after infection with VEEV and WEEV. Adult CD-1 mice infected by the intranasal (i.n.) route, showed that VEEV and WEEV enter the brain through olfactory sensory neurons (OSNs). In this study, we injected the mouse footpad with recombinant WEEV (McMillan) or VEEV (subtype IC strain 3908) expressing firefly luciferase (fLUC) to simulate mosquito infection and examined alphavirus entry in the CNS. Luciferase expression served as a marker of infection detected as bioluminescence (BLM) by in vivo and ex vivo imaging. BLM imaging detected WEEV and VEEV at 12 h postinoculation (hpi) at the injection site (footpad) and as early as 72 hpi in the brain. BLM from WEEV.McM-fLUC and VEEV.3908-fLUC injections was initially detected in the brain9s circumventricular organs (CVOs). No BLM activity was detected in the olfactory neuroepithelium or OSNs. Mice were also injected in the footpad with WEEV.McM expressing DsRed (Discosoma sp.) and imaged by confocal fluorescence microscopy. DsRed imaging supported our BLM findings by detecting WEEV in the CVOs prior to spreading along the neuronal axis to other brain regions. Taken together, these findings support our hypothesis that peripherally injected alphaviruses enter the CNS by hematogenous seeding of the CVOs followed by centripetal spread along the neuronal axis. IMPORTANCE VEEV and WEEV are mosquito-borne viruses causing sporadic epidemics in the Americas. Both viruses are associated with CNS disease in horses, humans, and mouse infection models. In this study, we injected VEEV or WEEV, engineered to express bioluminescent or fluorescent reporters (fLUC and DsRed, respectively), into the footpads of outbred CD-1 mice to simulate transmission by a mosquito. Reporter expression serves as detectable bioluminescent and fluorescent markers of VEEV and WEEV replication and infection. Bioluminescence imaging, histological examination, and confocal fluorescence microscopy were used to identify early entry sites of these alphaviruses in the CNS. We observed that specific areas of the brain (circumventricular organs [CVOs]) consistently showed the earliest signs of infection with VEEV and WEEV. Histological examination supported VEEV and WEEV entering the brain of mice at specific sites where the blood-brain barrier is naturally absent.
-
alphavirus e1 glycoprotein liposome nucleic acid complexes protect mice from lethal challenge with multiple alphaviruses
New Horizons in Translational Medicine, 2015Co-Authors: Amber B Rico, Ann M. Powers, Aaron T Phillips, Tony Schountz, Ann M Toth, Donald L Jarvis, Ken E OlsonAbstract:Alphaviruses are globally distributed, mosquito borne pathogens that cause death and disease in vertebrates, including humans. Therapeutics to combat alphaviral disease are non-existant and only a handful of IND status vaccines are available. Of the available vaccines most are associated with a poor immunological response and a high rate of reactivity, and none protects against more than a single alphavirus species. We designed and tested novel alphavirus vaccines comprised of the E1 glycoproteins of Western Equine Encephalitis virus (WEEV) or Venezuelan Equine Encephalitis virus (VEEV). Immunization with cationic lipid nucleic acid complexes (CLNCs) and alphavirus E1ecto mixture (lipid-antigen-nucleic acid complexes:LANACs) provided significant protection in mice challenged with either WEEV, VEEV or eastern Equine Encephalitis virus (EEEV) regardless of challenge route. LANAC immunized mice mount a strong humoral immune response lacking neutralizing antibody. Passive transfer of immune sera from LANAC immunized mice to non-immunized mice confers protection to challenge, indicating that non-neutralizing antibody is sufficient for protection. In summary, our LANAC vaccine has both therapeutic and prophylactic potential and is able to offer protection against distinct alphavirus species irrespective of the route of infection.
