Location: Operations2018 Annual Report
Objective 1. Develop the workforce needed to staff NBAF and fulfill the Foreign Animal Disease Research Unit’s mission to detect and control foreign animal diseases. Resources will be provided for academic-related expenses and the research projects that will enable the trainees to successfully achieve the academic requirements for obtaining degrees in one of the seven core scientific disciplines: pathology, virology, immunology, entomology, epidemiology, microbiology, and computational biology. Objective 2. Implement research projects under the direction and guidance of ARS scientists at the Foreign Animal Disease Research Unit (FADRU), PIADC, Orient Point, New York, and others in collaboration with FADRU.
Division A of the Consolidated Appropriations Act, 2017 (P.L. 115-31) contains an increase of $900,000 (NTL) for research on NBAF Workforce Development at the Center for Grain and Animal Health Research, in Manhattan, Kansas. The increased funds are to be used to establish a new ARS project, which will be held in the Office of the Center Director for the Center for Grain and Animal Health Research. There is a shortage of qualified scientists, including the availability of doctors of veterinary medicine (DVM) with a Ph.D degree, to conduct animal health research at the NBAF when the facilities become available in 2022. This will be addressed by specifically training scientists in the following seven core scientific disciplines: pathology, virology, immunology, entomology, epidemiology, microbiology, and computational biology. The objective and desired outcome is a mechanism to ensure a viable and qualified scientific workforce is available to implement a program to recruit and train scientists with expertise in biodefense research, with a focus on foreign and emerging animal diseases, including dangerous zoonotic pathogens. The mechanism for training scientists in biodefense research will be established in collaboration with the guidance of the American Association of Veterinary Medical Colleges. ARS does not presently have high containment facilities (BSL-3E, BSL-3Ag, and BSL-4) to train biodefense research scientists in Manhattan, Kansas. (However, through collaboration with Kansas state University, BSL-3Ag laboratories are available.)Therefore, the research projects needed to obtain a doctoral degree in one of the seven core scientific disciplines listed in the previous section will be conducted at the Plum Island Animal Disease Center (PIADC), Orient Point, New York, and/or the research facilities of collaborators contributing to the implementation of the ARS biodefense research programs. Dr. McVey, in collaboration with the National Programs Office, Plains Area Office, Atlantic Area Office, and PIADRU/ABADRU scientists will develop the execution plan for this project that will be in affect by September, 2017. It is expected that this will require agreements with multiple university partners. The agreements will define the operational methods and outcome expectations for training scientists capable of working on select agent animal diseases that are threats to U.S. animal agriculture.
The project team is evaluating multiple potential projects at multiple universities for inclusion in this project. The research projects listed below have been initiated at Mississippi State University to achieve these objectives: 1. Mechanisms of host-specific virulence and vector-enhanced immunity to orbiviruses. Need for Research: Bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) are animal orbivirus pathogens that cause noncontagious, insect-transmitted, hemorrhagic disease in domestic and wild ruminants world-wide (1-3). Severe economic losses from outbreaks result from effects on animal production and non-tariff trade restrictions on the sale and movement of animals and animal products. Losses to U.S. livestock industries attributed to BTV and EHDV have been conservatively estimated at $144 million annually (4). These viruses are of growing concern to livestock producers in North America due to 1) the emergence of new viral serotypes, 2) increased reports of spillover and clinical disease in cattle, and 3) increased spread and adaptation to new geographic areas. Although closely related and sharing distinctive common properties such as segmented double stranded RNA (dsRNA) genomes and characteristic non-structural proteins, BTV and EHDV cause disease in different specific hosts, primarily in sheep and white-tailed deer (WTD), respectively (5, 6). Recent progress in reverse genetics, viral sequencing, and in vitro and in vivo models have improved our understanding of orbiviral pathogenesis. However, the molecular mechanisms that determine orbiviral host specificity, the viral-insect interactions affecting virulence and clinical outcome, and the viral and insect factors which modulate protective innate and adaptive immune responses against orbiviruses remain elusive. Previous studies demonstrated that BTV capsid proteins VP2 and VP5 are involved in cell attachment and viral penetration into mammalian host cells, and neutralizing antibodies to VP2 and VP5 confer protective immunity (7, 8). Yet the molecular targets that determine host specificity are unknown. Toward this research need, we propose to identify molecular determinants of orbiviral capsid proteins that confer host susceptibility. (Obj. 1.) Unlike natural, midge-transmitted BTV infections which can result in 30-50% mortality, routine experimental infection of sheep by inoculation only rarely produces clinical disease beyond a transient fever and mild clinical signs depending on the infectious dose, inoculation route, and the BTV serotype used. It has been hypothesized that this difference is due to intradermal vs. subcutaneous routes of virus delivery, as well as interactions of the vector’s saliva with either the virus, the animal’s immune responses, or with both. Such ‘vector-enhanced’ transmission and pathogenesis has been reported for several arboviruses (9-11). Ongoing vector-host research with Culicoides midges and mice suggests the saliva deposited into the animal’s dermal layer during blood feeding elicits a very strong innate immune response which likely affects orbiviral infection. Additionally, Culicoides saliva contains proteins such as D7, protease inhibitors, and maltase which can induce hypersensitivity responses and may also affect orbiviral infection (12, 13). Understanding this vector-elicited response, the molecular determinants which confer host susceptibility, and the potential insect factors that may modulate orbiviral virulence and transmissibility, are critical to informing more efficacious vaccine strategies and developing potential methods for interrupting vector-borne transmission. Toward this research need, we propose to determine the effect of insect salivary proteins on orbiviral immunity in a natural host. (Obj. 2.) 2. Development and evaluation of a next generation ASFV live attenuated vaccine. Project objectives and Deliverables. Objective 1) Develop and assess next generation candidate ASFV vaccines using bioinformatics to determine additional genetic determinants of virulence in ASFV. (75% of Postdoctoral effort). Deliverable: a new vaccine candidate for ASF, incorporating an additional deletion to ASFV-G-delta9GLdeltaUK. Objective 2) Assess the host response to candidate ASFV vaccine by utilizing NGS technology to determine the differences in RNA expression profile of host target cells (15% of Postdoctoral effort). Deliverable: RNAseq analysis of host response in swine macrophages to new PIADC ASFV vaccine. Objective 3) Assess current circulating ASFV strains in Uganda by obtaining and sequencing by NGS field isolates from Uganda. (10% of Postdoctoral effort). Deliverable: Sequence of circulating ASFV strains in Uganda. 3. Inferred antigenic emergence associated with Quasispecies Dynamics and Subconsensus Variants of FMDV Development of effective, next-generation vaccines against exotic viruses that threaten U.S. livestock depends upon understanding of the mechanisms through which viruses evolve to evade host immunity. Specifically, viruses may elude vaccine-induced immunity by extremely rapid genomic mutation leading to antigenic variation. Recent work within the ARS Foreign Animal Disease Research Unit (FADRU) in Orient Point, New York, has characterized genomic substitutions in foot-and-mouth disease virus (FMDV) during distinct phases of infection in cattle. However, additional analyses are required to elucidate how these genomic changes affect FMDV antigenic structure and function. Scientists at Mississippi State University (MSU) have demonstrated expertise in computational approaches to correlate alterations of viral structural proteins with underlying genomic variability. The intention of this project will be to utilize existing next generation sequencing data from completed FMDV pathogenesis experiments to conduct novel analyses aimed at elucidating viral quasispecies dynamics and antigenic correlations. More specifically, FMDV evolution including genomic substitution and antigenic variation will be characterized throughout distinct stages of infection including the acute, transitional, and carrier phases. The execution of the project will include recruitment and training of a postdoctoral fellow who will be trained with the intention of future staffing of the National Bio- and Agro-Defense Facility (NBAF) in Manhattan Kansas. 4. Bioinformatics-based approaches to Identifying host mechanisms of Foot-and-Mouth Disease carrier state divergence. The development of the next-generations of vaccines against viruses that threaten U.S. agriculture, such as foot-and-mouth disease virus (FMDV), will depend upon understanding and enhancing the mechanisms of effective anti-viral immunity. Specifically, elucidating the host-mechanisms which determine clearance of infection under natural conditions may indicate critical pathways which may be exploited by novel countermeasures. Recent work within the ARS Foreign Animal Disease Research Unit (FADRU) in Orient Point, New York, has used microarray-based transcriptomic analyses to characterize host mechanisms of immunity to FMDV in cattle during distinct phases of infection. However, additional analyses are required to more thoroughly elucidate the relevant host pathways. Scientists at Mississippi State University (MSU) have demonstrated expertise in developing computational resources that improve the functional information of bovine genes such as addition of Gene Ontology, prediction of genes involved in host-pathogen interactions, etc. The intention of this project will be to utilize existing microarray data from completed FMDV pathogenesis experiments to conduct novel analyses aimed at elucidating endogenous and vaccine-induced mechanisms of anti-FMDV immunity in cattle. More specifically, we will utilize a number of open source bioinformatics tools including some developed at Mississippi State University for enhanced understanding of the functions and pathways in bovine immune mechanisms that contribute to carrier state versus clearance of FMDV. The execution of the project will include recruitment and training of a graduate student who will be trained with the intention of future staffing of the National Bio- and Agro-Defense Facility (NBAF) in Manhattan Kansas.
1. Mechanisms of host-specific virulence and vector-enhanced immunity to orbiviruses. Project planning has been completed between Mississippi State University (MSU) and Foreign Animal Disease Reserach Unit (FADRU) scientists. Recruitment has been initiated for the project trainee.
2. Development and evaluation of a next generation ASFV live attenuated vaccine. Project planning has been completed between Mississippi State University (MSU) and Foreign Animal Disease Reserach Unit (FADRU) scientists. A post-doctoral student has been hired and work has been initiated.
3. Inferred antigenic emergence associated with Quasispecies Dynamics and Subconsensus Variants. Project planning has been completed between Mississippi State University (MSU) and Foreign Animal Disease Reserach Unit (FADRU) scientists. Recruitment has been initiated for the project trainee.
4. Bioinformatics-based approaches to Identifying host mechanisms of Foot-and-Mouth Disease carrier. Project planning has been completed between Mississippi State University (MSU) and Foreign Animal Disease Reserach Unit (FADRU) scientists. Recruitment has been initiated for the project trainee.