Title: Neuron Specific Regulation of HSV1 and HSV2 Outcomes of Infection
PI: Andrea Bertke Co-I's/Collaborators: Seth Frietze
Significance: Herpes simplex viruses 1 and 2 (HSV1 and HSV2) establish latency in sensory and autonomic neurons, from which they can reactivate to cause recurrent disease throughout the life of the host, affecting more than 250 million people in the US alone. HSV replicates upon entry into some types of neurons, while other types of neurons naturally inhibit viral replication, resulting in latency. Exogenous stimuli trigger reactivation, but only from a portion of these latently infected neurons. The neuronal populations that support these divergent outcomes differ for HSV1 and HSV2, leading to different anatomical patterns and frequencies of recurrent skin lesions, blindness, pain, meningitis, or encephalitis.
We previously determined that in adult sensory neurons, continuous presence of certain neurotrophic factors maintains HSV in a latent state. Deprivation of these factors selectively induces HSV1 or HSV2 reactivation. We will now identify the specific neuronal signaling pathways that regulate HSV1 and HSV2 infection, determine how these neurotrophic factors selectively maintain HSV1 or HSV2 latency in neurons, and determine how deprivation of these factors induces viral reactivation. These studies will advance our understanding of HSV pathogenesis and enable development of more effective antivirals to prevent HSV recurrences and transmission.
Total Award: $1,719,314
Duration of Award: 6/2018 - 4/2023
Funding Agency: National Institute of Neurological Disorders and Stroke
Title: Church, Extension and Academic Partners Empowering Healthy Families
Significance: The long-term goals of this integrated project are to: 1) prevent and reduce childhood obesity through improved parenting practices and home environment related to obesity; 2) expand Extension capacity for community-engaged research and collaborative programming with faith-based organizations; 3) enhance Extension strategies for recruiting and training community volunteers to extend Extension reach; and 4) train future health professionals to provide culturally appropriate collaborative community-based health programs. Research, Extension and Education objectives support each goal. The project will target families with children ages 6 to 11 (first through fifth grade). The 14-month randomized control trial design of the research component will generate new knowledge regarding effectiveness of an integrated family-based intervention enhanced with social and environmental (church) support to prevent obesity in school-aged children. The project will address health disparities via the community-engaged approach in partnership with black churches. The interdisciplinary and cross-program nature of the project promotes attention to other USDA AFRI priorities including integration of research, Extension and education components and involvement of 4-H and eXtension. Undergraduate and graduate students from two land-grant universities will be trained on best practices for community-engaged research and outreach. Standard Extension program evaluation in addition to research data will provide maximum benefit to Extension programs and personnel by providing impact data for annual reporting, further supporting the Extension component of the integrated project.
Total Award: $2,250,310
Duration of Award: 3/2018 - 2/2023
Funding Agency: USDA National Institute of Food and Agriculture (NIFA)
Title: The role of gamma-aminobutyric acid (GABA) in the pathogenesis of Brucella
PI: Clay Caswell
Significance: Brucella spp. are bacteria that naturally infect a variety of domesticated and wild animals leading to abortions and sterility, and these bacteria are also capable of causing debilitating human infections, which often result from human exposure to infected animals and animal products. Brucella spp. are considered threats as potential biological weapons. Importantly, antibiotic treatment against brucellosis is prone to disease relapse, and there is currently no safe and effective vaccine to protect humans against infection with Brucella. The brucellae are intracellular pathogens that reside within immune cells called macrophages where they replicate in a specialized compartment, and the capacity of Brucella to survive and replicate within macrophages is essential to their ability to cause disease. Over the last few years, our laboratory has characterized a genetic pathway that is critical for the intracellular survival and pathogenesis of Brucella strains, and recently, we have discovered that one arm of this genetic circuitry controls the production of an ABC transport system, called GasABCDE, that is essential for Brucella virulence.
Preliminary experiments revealed that GasE is required for the ability of Brucella abortus to colonize experimentally infected mice. Moreover, bioinformatic analyses determined that GasABCDE is homologous to ABC transporters in other closely related bacteria that function in the import of -aminobutyric acid (GABA), and experiments in our lab have demonstrated that GasABCDE is a bona fide GABA transporter in B. abortus. We have also demonstrated that GABA uptake by the brucellae results in transcriptional changes, leading to the hypothesis that Brucella strains use GABA as a means of sensing the intracellular environment of the host macrophage. Overall, very little is known about the role of GABA in bacterial pathogenesis, and the current project is designed to define how GABA and the transport of GABA are linked to Brucella virulence. In the end, it may be possible to target bacterial GABA transport systems with novel vaccines and/or therapeutic strategies.
Total Award: $408,830
Duration of Award: 6/2018 - 5/2020
Funding Agency: National Institute of Allergy and Infectious Diseases
Title: Identification of novel HSV-1 ICP0 E3 ligase targets by mass spectrometry in neurons
PI: Andrea Bertke Co-I/Collaborator: David Davido
Significance: Herpes simplex virus 1 (HSV-1) infections cause a variety of diseases in humans, ranging from cold sores to blinding ocular infection and life-threatening encephalitis. The virus has two distinct phases of its life cycle: lytic and latent infections. Lytic infection produces new infectious virus and clinical symptoms. Latent infection, which only occurs in neurons, is a repressed state with no infectious virus or symptoms, but can reactivate to cause new lytic infection and recurrent symptoms throughout the life of the host. An HSV-1 protein, ICP0, is required for efficient viral replication and plays a pivotal role in the switch between latent and lytic infections through its E3 ubiquitin ligase activity. Recent studies suggest that ICP0 directs ubiquitination of selected host cell proteins that restrict viral gene expression in epithelial cells, leading to robust lytic infection. In neurons, however, where neuronal proteins restrict viral gene expression to drive the establishment of latency, the targets of ICP0-mediated ubiquitination and degradation are unknown. The objective of this project is to determine which unique neuronal factors ICP0 targets for ubiquitination and degradation to permit viral gene expression and replication. Results will contribute to identifying new cellular proteins involved in latency, which can be applied to the development of new antivirals to prevent HSV reactivation and recurrent disease.
Total Award: $437,772
Duration of Award: 2018 - 2020
Funding Agency: NIH/NINDS
Title: Maximizing Local Access to Therapeutic Deliveries in Glioblastoma
Significance: Glioblastoma (GBM), a primary brain tumor, remains an unmet medical need. The major obstacles to GBM treatment are the accessibility of GBM tumors to drugs through natural physiological and pathobiological barriers like the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB), respectively, and the adequate properties of drugs. In addition, complex pathobiology of GBM, including local invasion and intratumoral heterogeneity represent major challenges to generating effective anti-GBM drugs. The unifying theme of our PPG is the exploitation of local access to brain tumors like GBM to achieve and then maximize therapeutic effect in patients. This local access can be accomplished either by direct loco-regional delivery of drugs into the tumor mass and its vicinity or by disrupting the BBB/BBTB. For example, drugs can be delivered locally through convection-enhanced delivery (CED). The overall hypothesis of this PPG is that we can deliver the next generation of molecularly targeted drug candidates to GBM effectively by either significantly re-designed CED and/or by precision BBB/BBTB disruption. To address this hypothesis, we are developing convection-enhanced thermo-chemotherapy catheter system (CETCS) based on a novel arborizing catheter. Furthermore, the BBB disruption will be tested in two innovative ways using: (i) high-frequency irreversible electroporation (H-FIRE), or (ii) a combined approach of stem cells expressing tumor necrosis factor-α (TNF-α), a cytokine with a potential to significantly enhance BBB permeability, under a heat responsive promoter that can be remotely activated using high intensity focused ultrasound (HIFU). We will exploit a unique animal model of spontaneous gliomas in dogs, which is amenable to testing medical devices/surgical procedures, and thus is one of the most valuable tools in addressing our PPG’s unifying theme. We will explore our hypothesis in three Specific Aims. In Aim 1, we will generate targeted cytotoxic drugs with an increased access to tumors and/or pathophysiologically important tumor compartments. We will generate targeted drug conjugates with BBB-penetrating chemotherapeutics. In Aim2, we will attempt to bypass the BBB/BBTB by developing CED that addresses critical clinical needs. We will evaluate an arborizing catheter for broad distribution of infusates and accurate saturation of target volume in brain tissue. We will evaluate targeted drugs distribution and efficacy by CETCS for treating spontaneous GBM in a canine model. In Aim 3, we will bypass the BBB/BBTB by induced disruption. This will be achieved with H-FIRE treatment allowing for preferential targeting infiltrating tumor cells. We will assess H-FIRE protocols to combinatorially treat spontaneous gliomas in dogs with targeted cytotoxic agents. We will also examine stem cells engineered to express TNFα. Thus, our PPG proposal represents a combined rational approach of novel therapeutic approaches to improve delivery of unique drug candidates of enhanced access to GBM tumor and its compartments.
Total Award: $1,919,984
Duration of Award: 2017 - 2022
Funding Agency: NIH/NCIP01CA207206
Title: Meis1 Negatively Regulates Blood Flow in Hindlimb Ischemia
PI: Jia-Qiang He
Significance: Peripheral vascular disease (PVD) is a common circulatory disorder directly caused by a reduction or complete occlusion of blood flow of artery the lower extremities. In 2013, about 8.5 million Americans aged ≥ 40 years are affected by PAD and associated with significant morbidity, mortality, and economic burden. Unfortunately, no effective cures are available for PVD. The present medical interventions include traditional drug treatment, physical therapy and/or surgical vessel graft, which is only able to temporally relieving the clinical symptoms and oftentimes, the limb ends up to be amputated when treatments are failed. Thus, it is in an urgent need to develop alternative strategies either to treat the damaged or to regenerate the lost limb. Here, we propose to pursue this by exploring a new role of Meis1 gene in regulating vascular remodeling using hindlimb ischemic mouse model. Meis1 gene belongs to the three amino-acid loop extension (TALE) subclass of homeobox gene families and it plays a crucial role in embryogenesis, hematogenesis, homeostats, tumorigenesis, and cardiomyocytes proliferation. Up to date, little is known about the role of Meis1 in regulating arteriogenesis and angiogenesis under ischemic condition. Our preliminary study found that the endothelial cell (EC) specific knockout (KO) of Meis1 gene significantly increased blood flow of ischemic hindlimb in neonatal mice compared to wild type (WT) control. In addition, Meis1-KO also significantly attenuated necrotic/lost compared to control mice, suggesting that deletion of Meis1 gene in ECs provides significant protective effect against ischemia. The present project aims to investigate whether and how endothelial Meis1 gene regulates arteriogenesis following hindlimb ischemia using Meis1 transgenic mice. Completion of these aims will provide a better mechanistic understanding of Meis1-regulated arteriogenesis and/or angiogenesis under ischemic condition. The results may also reveal a new potential therapeutic approach leading a new drug discovery and treatment of PVD.
Total Award: $483,000
Duration of Award: 12/2017 - 11/2020
Funding Agency: NIH - NHLBI
Title: Evaluation of “State and Local Public Health Actions to Prevent Obesity, Diabetes, and Heart Disease and Stroke” for the Virginia Department of Health
Significance: Providing statewide external evaluation services for public health interventions to reduce obesity, heart disease and stroke, in Crater, Lord Fairfax, Portsmouth, Prince William and West Piedmont Health Districts.
Total Award: $338,000
Duration of Award: 2017 - 2020
Funding Agency: Centers for Disease Control and Prevention, through the Virginia Department of Health
Title: Elucidating the Mechanisms of PRRSV Immune Evasion Mediated by Nsp1a and Nsp2
PI: Nicholas Catanzaro Mentor: X.J. Meng
Total Award: $95,000
Duration of Award: 1/2017 - 12/2018
Funding Agency: USDA-NIFA
Title: Mechanisms Regulating Cerebral Arteriogenesis and Neurorestoration
PI: Michelle Theus CO-I: John Chappel, Hehuang Xie
Significance: Traumatic brain injury (TBI) is the most common acquired central nervous system (CNS) injury in the U.S, afflicting over 1.7 million Americans annually. Due to a paucity of safe and effective therapies, survivors are left with persistent motor and cognitive deficits that substantially reduce their quality of life. Mechanical damage to the cerebrovascular circulation creates an ischemic milieu, which exacerbates neural tissue loss. Therapies designed for neuroprotection and repair have underscored the importance of vascular health and remodeling in the trauma microenvironment. Interestingly, therapeutic arteriogenesis has become an important target for the prevention and treatment of peripheral tissue ischemia, however, limited information exists regarding its effects on neural preservation and recovery of function within the CNS. The overarching goal of our research is to provide important mechanistic insight into the pathophysiological relevance of cerebral arteriogenesis following TBI. Specifically, the current study will employ a novel cell-specific, transgenic murine approach to investigate the central role of Eph signaling in suppressing arteriogenesis. Unraveling the molecular mechanism(s) underlying this important adaptive response and its potential as a therapeutic target for neurorestorative intervention in the brain may reveal novel targets for drug discovery.
Total Award: $1,730,277
Duration of Award: 4/2016 - 3/2021
Title: Characterization of a novel genetic pathway required for Brucella virulence
PI: Clayton Caswell
Significance: Brucella spp. are bacteria that naturally infect a variety of domesticated and wild animals leading to abortions and sterility. These bacteria are also capable of causing debilitating human infections, which often result from human exposure to infected animals and animal products. Additionally, Brucella spp. are considered threats as potential biological weapons. Currently, there is no safe and effective vaccine to protect humans against infection with Brucella, and antibiotic treatment against brucellosis is prone to disease relapse. During the course of an infection, the Brucella reside within immune cells called macrophages where they replicate in a specialized compartment, and the ability of Brucella to survive and replicate within macrophages is essential to their ability to cause disease. We have recently discovered that a transcriptional regulator, which we have named VtlR, is required for the ability of the bacteria to survive and replicate within host cells, and moreover, this regulator is essential for chronic Brucella colonization in an animal model of infection.
Preliminary data has led to the hypothesis that VtlR controls the expression of essential genes for Brucella pathogenesis. We have determined that VtlR regulates the expression of a limited subset of three genes putatively encoding small hypothetical proteins. Strikingly, these hypothetical proteins are highly conserved among numerous bacterial species, both pathogenic and beneficial, but there is currently no information regarding the molecular function(s) of these proteins in prokaryotic biology. The objective of this proposal is to define these novel virulence-associated elements in Brucella spp. In turn, these proteins may be targeted in new therapeutic strategies to combat Brucella infections, or to develop a human vaccine against brucellosis. Moreover, these studies will shed light on the role of these novel protein elements in a wide variety of bacteria, and it is possible that these proteins may be exploited as a means of alleviating detrimental infections, as well as enhancing beneficial bacteria-host interactions.
Total Award: $458,638
Duration of Award: 9/2015 - 8/2018
Funding Agency: National Institute of Allergy and Infectious Diseases
Title: Characterizing virulence-associated small RNAs of Brucella abortus
PI: Clayton Caswell
Significance: Brucella spp. are bacteria that naturally infect a variety of domesticated and wild animals leading to abortions and sterility. These bacteria are also capable of causing debilitating human infections, which often result from human exposure to infected animals and animal products. Importantly, Brucella infections are only rarely fatal in humans, but in these cases of lethal brucellosis, the principal cause of death is endocarditis. Currently, there is no safe and effective vaccine to protect humans against infection with Brucella. During the course of an infection, the Brucella reside within immune cells called macrophages where they replicate in a specialized compartment. The ability of Brucella to survive and replicate within macrophages is essential to their ability to cause disease. One of the ways in which Brucella survive in macrophages is by using two small regulatory RNAs (sRNAs), called AbcR1 and AbcR2. Mutation of the abcR1 and abcR2 genes leads to attenuation of Brucella abortus in macrophages and a murine model of chronic infection. While it is known that the AbcR sRNAs are important in the infection process of Brucella, it is not fully understood how these sRNAs function at the molecular level. The objective of this proposal is to define the novel genetic regulatory elements of the AbcR sRNAs in Brucella spp. In turn, these elements may be targeted in new therapeutic strategies to combat Brucella infections, or to develop a human vaccine against brucellosis. Overall, the proposed work with will aid in the elimination of chronic brucellosis and, thus, advance the development of means in which to eradicate Brucella endocarditis.
Total Award: $308,000
Duration of Award: 1/2015 - 12/2018
Funding Agency: American Heart Association