Location: Foreign Animal Disease Research2013 Annual Report
1a. Objectives (from AD-416):
The objective of this collaborative research project is to accelerate the development of vaccine technology for two critical cattle diseases; foot-and-mouth disease (FMD) and east coast fever (ECF), impacting smallholder farmers in sub-Saharan Africa. We will utilize vaccine development technologies which assess breed specific host responses to pathogens utilizing existing genome sequences for two targeted pathogens and the genome sequence of the host species, Bos taurus. ARS, PIADC will lead the effort to analyze the immune response to FMDV infection in cattle as well as the analysis of FMD vaccine performance.
1b. Approach (from AD-416):
The bovine immune response to FMDV infection will be assessed through bioinformatics, high-throughput sequencing, peptide synthesis, proteomics and ultimately the major histocompatibility complex (MHC) tetramer technology or "tetramers". ARS will expand the present collaboration with the University of Vermont to achieve a more technically sophisticated and informative analysis of the immune response of cattle to FMDV infection and to vaccination with virus vectored FMD vaccines. This is made possible by utilizing the genetically defined animals from the University of Vermont's herds of Holstein cattle, or from the University of Vermont Dairy Center of Excellence cooperator herds.
3. Progress Report:
In FY 2013 the following activities were conducted: 1. We have expanded on our analysis of bovine lymphyocyte (BoLA) Class II expression in Holstein cattle. We established a method for determining gene alleles of cattle, which allows us to infer the MHC class II haplotype and determined accuracy. We have typed over 120 cattle and identified 4 dominant BoLA class II haplotypes which are present in 92% of animals tested. Using these methods, we determined the MHC class II haplotypes for 22 cattle. The three most common haplotypes found in the herd were chosen for tetramer production under objective 2. Further patterns of allelic expression are being identified in individual animals contributing to our understanding of class II gene expression which allows us to infer the MHC class II haplotype and the potential relationship between class I and class II expression. In addition in FY 2013, 2 molecules called DR and DQ, from Bovine haplotype 24a, have been identified for synthesis. One class II protein has been synthesized. Sequencing of the remaining proteins is underway. A total of 8 molecules are in production that will allow for 6 tetramers to be made. Assays to quantify peptide-tetramer binding affinity have been successfully developed for human MHC class II proteins at our collaborators lab at the University of Copenhagen and we demonstrated these assays work for bovine proteins as well. This technology is now being transferred to UVM. No technologies were transferred to other entities and no publications were written during this fiscal year.