Project description:To study emergence of resistance to BDGR-49 during infection with Venezuelan equine encephalitis virus (VEEV), mice were treated suboptimal treatment regimen. C3H/HeN mice were prophylactically treated with BDGR-49 2 hours prior to infection for a total of 5 days. Mice were infected with a lethal challenge dose of VEEV TC-83. Following infection mice brains were euthanized on 3-, 5-, 7,9-, and 10-days post-infection and their brains collected and RNA-Seq performed on. RNA-Seq results were used to analyze for viral resistant mutants. Analysis revealed that only one of the mice contained a mutant that is potentially resistant to BDGR-49.
Project description:Infections by the New World alphaviruses, Eastern Equine encephalitis virus (EEEV), Venezuelan Equine encephalitis virus (VEEV), and Western Equine encephalitis virus (WEEV), cause febrile illness that can progress to fatal disease in humans and equids. Currently there are no FDA-approved antivirals for prophylactic or therapeutic treatment of human infection by these viruses. To combat these infections, we have developed a novel small molecule, BDGR-164, which has subnanomolar potency against VEEV, EEEV, and WEEV. Using an intranasal route of virus infection in a lethal BALB/c model, prophylactic subcutaneous administration of BDGR-164 conferred 100% (VEEV), 88% (EEEV), and 63% (WEEV) survival. To evaluate the ability of BDGR-164 to reduce viral RNA/antigen, inflammation, and pathogenesis, we used RNASeq and histopathology of whole brain at 4 days post-infection (dpi). Viral RNA levels and antigen were reduced significantly in virus-infected and BDGR-164-treated versus virus-infected, sham-treated mice. Moreover, there was a significant reduction in host immune responses associated with inflammatory signaling, immune cell recruitment, and programmed cell death in virus-infected, BDGR-164 treated mice. Cytokine analyses of sera corroborated the reduction in upregulation of the immune response in virus-infected, BDGR-164 treated mice. Limited antiviral resistance to BDGR-164 was detected in one mouse on 4 dpi at NSP2:Y102C. In conclusion, our studies suggest that BDGR-164 has broad and potent prophylactic efficacy against the neurotropic alphaviruses.
Project description:Venezuelan equine encephalitis virus (VEEV) causes encephalitis in humans and equids, and there are no vaccines or therapeutics available for humans. In recent years, non-coding RNAs have emerged as critical regulatory factors affecting different cellular pathways. Specifically, long non-coding RNAs (lncRNAs) have been identified as regulators of antiviral pathways during various viral infections; however, their role in regulating VEEV infection has not been assessed. Here we show differential expression of several lncRNAs in primary mouse target cells infected with a vaccine strain of VEEV (TC-83) but not a pathogenic strain (TrD). Among the differentially expressed genes (DEGs), suppressing lncRNA small nucleolar RNA host gene 15 (Snhg15) resulted in about a 7-fold increase in VEEV TC-83 replication in primary mouse a strocytes. Knockdown of Snhg15 during VEEV TC-83 infection resulted in thesuppression of ten genes including Irf1, Junb, Atf3, Relb, Pim1, Hbegf, Ccl5, Ankrd33b, and H2-K2, all of which were also increased during TC-83 infection when the expression of Snhg15 increased in primary mouse astrocytes. Most of these genes are involved inantiviral responses. KEGG pathway analysis confirmed the suppression of both pattern recognition receptor and inflammatory pathways after in Snhg15 knockdown. These data are the first to identify lncRNA responses in encephalitic alphavirus infection and demonstrate important roles for these overlooked RNAs on VEEV infection.
Project description:Venezuelan equine encephalitis virus (VEEV) causes encephalitis in humans and equids, and there are no vaccines or therapeutics available for humans. In recent years, non-coding RNAs have emerged as critical regulatory factors affecting different cellular pathways. Specifically, long non-coding RNAs (lncRNAs) have been identified as regulators of antiviral pathways during various viral infections; however, their role in regulating VEEV infection has not been assessed. Here we show differential expression of several lncRNAs in primary mouse target cells infected with a vaccine strain of VEEV (TC-83) but not a pathogenic strain (TrD). Among the differentially expressed genes (DEGs), suppressing lncRNA small nucleolar RNA host gene 15 (Snhg15) resulted in about a 7-fold increase in VEEV TC-83 replication in primary mouse astrocytes. Knockdown of Snhg15 during VEEV TC-83 infection resulted in the suppression of ten genes including Irf1, Junb, Atf3, Relb, Pim1, Hbegf, Ccl5, Ankrd33b, and H2-K2, all of which were also increased during TC-83 infection when the expression of Snhg15 increased in primary mouse astrocytes. Most of these genes are involved in antiviral responses. KEGG pathway analysis confirmed the suppression of both pattern recognition receptor and inflammatory pathways after in Snhg15 knockdown. These data are the first to identify lncRNA responses in encephalitic alphavirus infection and demonstrate important roles for these overlooked RNAs on VEEV infection.
Project description:Experimental V4020 is derived from VEEV TC-83, a vaccine with a long track record of use in lab and military personnel at risk. V4020 was generated from an infectious DNA clone, secured genetic stability by employing stabilizing mutation at position 120 in the E2 protein, and by rearrangement of structural genes. In this study, serial passages in brain tissues of mice were performed to compare safety and genetic stability of V4020 and TC-83 experimental vaccines. During five serial passages in brain, less severe clinical manifestations and lower viral load were observed in V4020 mice and all animals survived. In contrast, 13.3% of mice met euthanasia criteria during the passages in TC-83 group. At 2 DPI, RNA-Seq analysis of brain tissues revealed that V4020 mice had lower rates of mutations throughout five passages. Higher synonymous mutation ratio was observed in the nsP4 (RdRP) gene of TC-83 compared to V4020 mice. At 2 DPI, both viruses induced different expression profiles of host genes involved into neuro-regeneration. Taken together, these results provide evidence for the improved safety and genetic stability of the experimental V4020 VEEV vaccine in a murine model. While no single nucleotide polymorphisms that have been previously linked to virulence were identified, more neuro-virulence markers were observed in serial passaged TC-83 compared to V4020. This study suggests a complex polygenic basis for neuro-virulent reversion in VEEV live attenuated vaccines and provides evidence for the advanced safety and genetic stability of V4020.
Project description:Venezuelan, Western and Eastern Equine Encephalitis Virus (VEEV, WEEV and EEEV), genus Alphavirus, causes a febrile illness that may result in fatal neurological disease which has no FDA-approved antivirals for the prevention or treatment. To address this gap, we developed a novel brain-penetrant, small molecule, BDGR-49, which when administered subcutaneously at 6 mg/kg twice per day for 6 days conferred 100% protection against a lethal intranasal challenge of VEEV Trinidad donkey (TrD) in BALB/c mouse model. By eight days post-infection (dpi), viral load in the brain of BDGR-49-treated mice was significantly reduced whereas TrD-infected, sham-treated mice succumbed to disease on 5 dpi. Analysis of the host responses in the brains of VEEV TrD-infected, BDGR-49-treated, mice resulted in a significant reduction in expression of genes in pathways associated with inflammation and cell death.
Project description:Viral infections, including Venezuelan equine encephalitis virus (VEEV), have been likened to neurological diseases such as Parkinson’s and Alzheimer’s, though mechanisms remain unclear. VEEV, a neuroinvasive alphavirus, can cause significant neurological deficits in humans. Chronic effects of VEEV are poorly understood, with no antivirals or neuroprotective treatments available. This study examines longitudinal neuropathological, behavioral, and single-cell transcriptomic changes in C57BL/6 mice intranasally infected with VEEV TC-83. Acute infection significantly altered inflammatory and innate immune signaling and induced astrocyte and microglia activation and loss of neurons in the hippocampus. Persistent motor dysfunction, memory impairment, and reduced anxiety-like behavior were observed up to 106 days post-infection (DPI). These changes correlated with alterations in synaptogenic signaling gene expression, neuron loss, and persistent glia cell activation at 106 DPI. Collectively, this study demonstrates that infection with VEEV induces chronic alterations in the hippocampus that may correlate with neurological sequalae observed in human patients.