2012 Annual Report
1a.Objectives (from AD-416):
To improve Foot-and-Mouth Disease Virus (FMDV) vaccine potency and duration of immunity, we will study the cellular immune response to infection and the ability to refine the killed virus vaccine for FMDV or the recombinant empty capsid vaccine. The objective of this agreement is to analyze T cell responses to FMDV infection in swine and cattle.
1b.Approach (from AD-416):
The state of the art for analysis of the cellular immune response of T lymphocytes to vaccination is: identification of T cell epitopes, mapping of those epitopes to the presenting transplantation antigens known as histocompatibility complex (MHC) molecules and developing MHC tetramers for tracking T cell responses. This technology is used extensively in laboratory mice but is expensive in a genetically diverse human population. Even given the expense, the technology is being applied in the clinic more and more often. Our preliminary studies indicate common cattle breeds, such as Holstein, can be analyzed using this technology.
The University of Copenhagen will generate the information required to design and test MHC tetramers for analysis of cellular immune reponse to Foot-and-Mouth Disease Virus(FMDV). ARS, PIADC will utilize this information to analyze responses of cattle and swine to vaccination and FMDV infection.
The objectives of this collaboration are to improve Foot-and-Mouth Disease Virus (FMDV) vaccine potency and duration of immunity through the study of the cellular immune response to infection and the response to the killed virus vaccine for FMDV or the recombinant empty capsid vaccine in swine and cattle. Specifically, the mapping and identification of potential T cell (white blood cells) epitopes will allow more accurate tracking T cell responses and thus assessment of vaccine performance.
During FY 2012, our collaborators at University of Vermont (UVM) screened the research herd of Holstein cattle at the UVM using methods to determine the expression of class I major histocompatiblity (MHC) genes developed in the previous reporting period. They identified 6 MHC class I genes that are highly expressed in the herd. These genes are now being expressed as recombinant proteins in our lab for analysis of FMDV peptide binding.
Our PIADC colleagues applied the technology developed at Washington State University to determine expression of MHC II genes in Holsteins, again analyzing cattle from the UVM herd. They identified 6 class II MHC gene products that account for over 90% of the MHC II genes expressed in the experimental herd UVM and the proteins for the first of all of these are being generated here at University of Copenhagen for analysis of FMDV protein derived T cell peptide epitopes.
The major accomplishments over the life of this project include: 1. Establishment of functional porcine MHC class I molecules and analysis of their specificity. 2. Establishment of predictors covering porcine MHC class I molecules. 3. Establishment of recombinant reagents suitable for tetramer staining of porcine T cells. 4. Determined that the response of pigs to FMDV vaccination is dominated by a single T cell epitope. 5. Identification of the class I and class II MHC genes most commonly expressed in the University of Vermont experimental herd of cattle. 6. Production of class I and class II bovine MHC proteins for further analysis.
During FY 2012, a PIADC postdoctoral collaborator and a University of Vermont PhD student spent 4 weeks in the Copenhagen laboratory learning the process of using the bioinformatics for MHC peptide binding prediction and making tetramers for analysis of T cell responses. A graduate student from Copenhagen has spent 6 weeks at PIADC analyzing procine T cell responses to vaccination against FMDV using MHC tetramers.
The following technologies have been transferred in FY 2012: 1. The information and reagents have been transferred from Copenhagen to ARS, PIADC. 2. The ability to generate tetramers has been transferred from Copenhagen to ARS, PIADC. 3. The dominant alleles of the bovine MHC locus have been identified and transferred to University of Copenhagen for protein expression.
The following publications were produced during the reporting period:
Pedersen, LE, M. Harndahl, M. Nielsen, J. R. Patch, G. Jungersen, S. Buus, and W. T. Golde. (2012). Identification of peptides from foot-and-mouth disease virus structural proteins bound by class I swine leucocyte antigen (SLA) alleles, SLA-1*0401 and SLA-2*0401. Animal Genetics. In Press.
Pedersen, LE, MN Harndahl, M Rasmussen, K Lamberth, WT Golde, O Lund, M Nielsen, and S Buus. (2011) Generation of porcine major histocompatibility complex (MHC) class I molecules and analysis of their peptide-binding specificities; extending the human NetMHCpan predictor to porcine MHC’s. Immunogenetics. 63:821-834.
Patch, JR, LE Pedersen, FN Toka, M Moreas, MJ Grubman, M Nielsen, G Jungersen, S Buus, and WT Golde. (2011). Induction of foot-and-mouth disease virus (FMDV) specific cytotoxic T cell killing by vaccination. Clinical and Vaccine Immunology. 18: 280-288.