Location: Animal Parasitic Diseases Laboratory2013 Annual Report
1a. Objectives (from AD-416):
ARS will expand its analysis of PRRS Host Genetics Consortium (PHGC) samples to address mechanisms of PRRS resistance/susceptibility and biologic responses to PRRS virus (PRRSV) infection. This grant will focus on PRRS viral persistence in tonsil and assess host immune and viral mechanisms involved in persistence. In addition it will update the PHGC database and website http://www.animalgenome.org/lunney/index.php for improved data resources for Consortia member usage and for public access and education.
1b. Approach (from AD-416):
ARS has led the PRRS Host Genetics Consortium (PHGC) project the goal of which is to identify genetic determinants of resistance/susceptibility of commercial swine to porcine respiratory and the reproductive syndrome virus (PRRSV) infection and associated growth effects. ARS will apply for NPB funds to perform the proposed research on PRRS viral persistence. The objectives for this work are 1) Determine levels of PRRS viral RNA in porcine tonsils of PHGC pigs to assess PRRS persistence; 2) Assess tonsil tissue RNA for immune correlates of PRRSV persistence; and 3) Expand the capacity of the PHGC database and improve public/private interface. ARS will provide funds to the ISU COOPERATOR for their efforts for objective 3) to update the PHGC database and website.
3. Progress Report:
This new grant focuses on Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), the most economically important swine production disease worldwide. It addresses a major issue of this virus, i.e., viral persistence. Due to tissue persistence, the infection can be reactivated and cause additional losses to the affected producer. As part of the PRRS Host Genetics Consortium (PHGC) tonsil samples were collected from every pig (~3000 total) that survived the PRRSV infection. To date, the first set of tonsil samples have been processed for RNA and are now being assessed for the level of PRRSV RNA. These results will enable us to address the questions concerning PRRS persistence, e.g. are serum viral levels predictive of the tonsil level, do host genes control viral persistence. All PHGC data is being stored in the secure, password protected PHGC relational database: http://www.animalgenome.org/lunney/index.php. For this grant, ARS scientists at the Beltsville Agricultural Research Center (BARC) in Beltsville, Maryland are working with Iowa State University (ISU) to update the PHGC database. It started with a redesign of the website to make data access more user-friendly and enhance search functions, as well as improve the overall look of the website. Other materials include secure sites for pre-publication sharing of abstracts and articles, as well as public news sites. Additional functions added to the website include a page that is designed to handle Power Point slides of presentations made by PHGC members.