Location: Ruminant Diseases and Immunology Research
2023 Annual Report
Objectives
Objective 1: Determine the impact of variant and emerging viruses as causative agents of respiratory disease in ruminants, with special emphasis on the role of Bovine Viral Diarrhea virus (BVDV).
Subobjective 1A: Conduct whole genome phylogenetic analyses to support molecular epidemiological studies to characterize and determine the significance of ruminant respiratory viruses currently circulating in United States.
Subobjective 1B: Identify the molecular determinants that drive strain prevalence, emergence, evolution, virulence, and transmission of bovine respiratory viruses.
Subobjective 1C: Conduct metagenomic analyses of respiratory samples from feedlot cattle to determine presence and significance of bovine respiratory viruses.
Objective 2: Elucidate the host-pathogen interactions associated with the Bovine Respiratory Disease Complex.
Subobjective 2A: Identify host factors associated with viral infection that predispose to respiratory disease.
Subobjective 2B: Characterize cellular and humoral responses that drive protective immunity against viral respiratory pathogens.
Subobjective 2C: Characterize functional genomics of the host associated with susceptibility to respiratory disease.
Objective 3: Develop intervention strategies for controlling viral respiratory infections of ruminants.
Subobjective 3A: Develop vaccines and vaccination strategies that provide better cross-protection against emerging and antigenic variant field strains.
Subobjective 3B: Improve existing diagnostic tests and testing strategies for the early detection of respiratory viral pathogens of ruminants on relevant farm settings.
Subobjective 3C: Develop biotherapeutic platforms for feedlot cattle that induce rapid onset of immunity as a companion to respiratory disease vaccination.
Approach
Bovine respiratory disease (BRD) is a major cause of production losses to the cattle industry. The aim of the research in this project plan is to provide scientific information to better understand the viral pathogenesis of BRD. In particular, the disease dynamics of host-pathogen interactions responsible for the BRD will be investigated. Agents of interest include bovine viral diarrhea virus (BVDV), bovine herpes virus-1 (BHV-1) and bovine respiratory syncytial virus (BRSV). This research will involve a multidisciplinary approach to address the broad and ambitious goal of controlling viral diseases of cattle, with a priority on respiratory viral pathogens. The approach used here is consistent with the multifactorial nature of bovine respiratory disease, as it results from an interplay of infection by multiple viral and bacterial pathogens, stress, immune dysfunction and environmental factors. The first objective of this project addresses the impact of variant and emerging viruses. Screening to determine the incidence of variant and emerging viruses will require the development of surveillance tools and methods to measure impact. This will lead to a greater understanding of viruses that play a role in BRD. A major question here is evaluation of currently marketed vaccines and whether it will be necessary to modify them to protect against emerging/variant viruses. There is a need to identify newly emerging/variant viruses that interact with the host in producing BRD. A second objective examines host/pathogen interactions, specifically to determine how respiratory viral pathogens interact with the host to moderate innate and adaptive immune responses. This includes interaction between BVDV, BRSV, BHV-1 and emerging/variant viruses. It is established that most BRD involves interactions of multiple agents, both viral and bacterial, thus experiments involving multiple agents will be conducted to examine this interplay and how each contributes to BRD. The third objective of this project plan involves defining events that promote the production of a strong, protective immune responses (both innate and acquired immunity). Results from this will reveal targets or points of intervention that can be utilized in the development of robust vaccines and management regimens that reduce the impact of BRD. The knowledge gained here will be used for the design of new vaccines, including subunit vaccines, or for providing greater knowledge for the selection of virus strains to be used in vaccines. This part of the project will evaluate the practical applications of information generated in the form of improved vaccines or vaccination strategies. The ultimate, cumulative goal of this research is to improve control of viral respiratory pathogens that will enhance cattle health and well-being, and reduce production costs for farmers and ranchers.
Progress Report
In support of Objective 2, we identified a bovine respiratory syncytial virus (BRSV) fusion (F) protein epitope. An epitope is the part of a pathogen that an antibody attaches to. We found that a bovine major histocompatibility allele presents a BRSV F protein epitope to a specific white blood cell subset. In order to identify these specific white blood cells during BRSV infection, a reagent has been synthesized under a collaborative agreement with a National Institutes of Health facility. We have received that reagent and will use it to identify specific white blood cells in calves responding to BSRV. This information will be important in the refinement of vaccine formulations for bovine respiratory disease.
In support of Objective 2, a total of 732 blood samples were received from West Texas A&M University, in a collaboration study with Mississippi State University and the National Animal Disease Center. The objective is to identify transcripts that are differentially expressed in animals vaccinated against bovine viral diarrhea virus (BVDV). The animals were sampled at days 0, 14, and 28, after vaccination. Currently we have extracted RNA from all samples. Sequencing has been done in all samples from days 0 and 14. Samples from day 28 will be sequenced soon. Bioinformatics analysis is being initiated in samples from day 0. Following this analysis, bioinformatics will be done in samples from day 14.
In support of Objective 3, a biotherapeutic protein from our collaborators at the Plum Island Animal Disease Center (PIADC) was received. We have successfully tested this biotherapeutic protein (antiviral protein) on a selected bovine viral diarrhea virus (BVDV) isolate under in vitro cell culture conditions. The new biotherapeutic protein was able to substantially neutralize BVDV, in a concentration-dependent manner. This antiviral protein expression construct was recently obtained from PIADC, and the in vivo anti-BVDV activity of the construct will be tested in a calf model of BVDV. Additionally, several immunostimulants which have been previously identified were tested in vitro for their abilities to stimulate cattle peripheral blood mononuclear cells to produce early immune responses (cytokines). We have now identified an immunostimulant that produces the best early and broad immune response, and it will be incorporated into future BVDV nanovaccines.
Accomplishments
1. Identification of a Respiratory Syncytial Virus (RSV) protein component recognized by bovine white blood cells which will aid in vaccine development. Human respiratory syncytial virus (HRSV) infects nearly every child by 2 years of age and subsequent reinfections can occur later in life. No safe, effective vaccines have been developed for HRSV. Bovine respiratory syncytial virus (BRSV) is a related virus of cattle that is highly similar to HRSV and, like HRSV, causes significant respiratory disease in calves making BRSV an attractive model for vaccine development to both BRSV and HRSV. To better understand the immune response to BRSV infection, ARS researchers in Ames, Iowa, assessed white blood cell subset responses in cows with a history of annual vaccinations. An assay and reagents were developed which allowed for the identification of a specific RSV protein component recognized by a subset of bovine white blood cells. This information will be of interest to researchers, veterinarians, and producers interested in vaccine development.
2. Development of novel RSV vaccine reduces viral load in the upper respiratory tract and lungs of calves. Human respiratory syncytial virus (HRSV) is a major cause of severe lower respiratory tract disease in infants and the elderly, yet no safe and effective vaccine is commercially available. A closely related virus, bovine RSV, causes respiratory disease in young calves, with many similar features to those seen in HRSV, gross and microscopic lesions. It was of interest to determine whether a NDV-vectored vaccine would be protective in a neonatal calf BRSV infection model. ARS researchers in Ames, Iowa, constructed novel RSV vaccine. The RSV vaccine was well-tolerated by colostrum-deprived calves in which no untoward clinical signs were noted following administration of primary or booster vaccines and there was no evidence of vaccine-enhanced disease in the upper airways or lungs of calves receiving the vaccine, compared to the non-vaccinated control calves. While a single intranasal administration failed to induce protection, it was found that two intranasal doses reduced severity of gross and microscopic lung lesions and decreases viral load in the upper respiratory tract and lungs. In addition, neutralizing antibodies were generated in serum of colostrum-deprived calves administered the vaccine. Moreover, vaccinated calves had reduced levels of CXC inflammatory molecules in lesioned lung samples compared to non-lesioned samples. Reduced expression of these molecules likely played a role in decreased lesion severity and a reduction in cellular infiltration into RSV-inflamed lungs. In summary, it was shown that the vaccine is safe in colostrum-deprived calves, reduces severity of lung lesions, and decreases viral load in the upper respiratory tract and lungs. This information will be of use to researchers, veterinarians and producers interested in vaccine development.
3. Response of heifers vaccinated against bovine viral diarrhea virus with a combination of multivalent modified live and inactivated viral vaccines. Bovine viral vaccines, as either live or killed formulations, are widely used in the field. Moreover, they are often used in combination by vaccinating with one type and then re-vaccinating with the other. However, despite various reports that certain combinations are better than others, very few studies have actually evaluated how vaccinations with these different vaccines impacts the ability of the animal to respond to subsequent re-vaccination with the other type. ARS researchers in Ames, Iowa, completed a thorough analysis of the immune response of cattle following vaccination with a live or killed vaccine, followed by re-vaccination with the other type. This new information will be of interest to researchers, veterinarians and producers interested in developing and improving upon vaccination regimens against bovine viruses.
Review Publications
Sacco, R.E., Mena, I., Palmer, M.V., Durbin, R.K., Garcia-Sastre, A., Durbin, J.E. 2022. An intranasal recombinant NDV-RSV F opt vaccine is safe and reduces lesion severity in a colostrum-deprived calf model of RSV infection. Scientific Reports. 12(1). Article 22552. https://doi.org/10.1038/s41598-022-26938-w.
Ruiz De La Cruz, G., Sifuentez-Runcon, A.M., Casas, E., Sanchez, F.A., Parra-Bracamontes, G., Riley, D., Perry, G., Welsh, T., Randel, R. 2023. Genetic variants and their putative effects on microRNAseed sites: Characterization of 3’ untranslated region of genes associated with temperament. Genes. 14(5). Article 1004. https://doi.org/10.3390/genes14051004.
Kaplan, B.S., Hofstetter, A.R., McGill, J.L., Lippolis, J.D., Norimine, J., Dassanayake, R.P., Sacco, R.E. 2023. Identification of a DRB3*011:01-restricted CD4+ T cell response against bovine respiratory syncytial virus fusion protein. Frontiers in Immunology. 14. Article 1040075.. https://doi.org/10.3389/fimmu.2023.1040075.
Ma, H., Lippolis, J.D., Casas, E. 2022. Expression profiles and interaction of microRNA and transcripts in response to bovine leukemia virus exposure. Frontiers in Veterinary Science. 9. Article 887560. https://doi.org/10.3389/fvets.2022.887560.
Casas, E., Falkenberg, S.M., Dassanayake, R.P., Register, K.B., Neill, J.D. 2022. MicroRNA profiles for different tissues from calves challenged with Mycoplasma bovis or challenged with Mycoplasma bovis and bovine viral diarrhea virus. PLoS ONE. 17(7): Article e0271581. https://doi.org/10.1371/journal.pone.0271581.
Paredes-Sanchez, F.A., Sifuentes-Rincon, A.M., Lara-Ramirez, E.E., Casas, E., Rodriguez-Almeida, F.A., Herrera-Mayorga, E.V., Randal, R.D. 2023. Identification of candidate genes and SNPs related to cattle temperament using a GWAS analysis coupled with an interacting network analysis. La Revista Mexicana de Ciencias Pecuarias. 14(1):1-22. https://doi.org/10.22319/rmcp.v14i1.6077.
Dassanayake, R.P., Clawson, M.L., Tatum, F.M., Briggs, R.E., Kaplan, B.S., Casas, E. 2023. Differential identification of Mannheimia haemolytica genotypes 1 and 2 using colorimetric loop-mediated isothermal amplification. BMC Research Notes. 16. Article 4. https://doi.org/10.1186/s13104-023-06272-8.
