Project Number: 5348-32000-029-00
Project Type: Appropriated

Start Date: Aug 01, 2007
End Date: Feb 28, 2012

Objective:
(1) Determine the genetic organization and expression of Ovine MHC Class I, IIa, and IIb loci, (2) Determine and validate that specific MHC Class I and/or MCH Class II alleles associate with OPPV clinical disease phenotypes and, (3) Determine the functional significance and subsequent immune responses of MHC alleles that associate with OPPV clinical disease phenotypes.

Approach:
OPPV is a sheep lentivirus that infects 24% of U.S. sheep flocks and causes economic losses to the sheep producer due to mastitis, dypsnea, and lameness. Serological diagnostic tests which test for the presence of anti-OPPV antibodies have provided a highly sensitive and specific means of testing but have not shown statistical correlations with pathology or other clinical markers of disease. Therefore, an OPPV test that predicts or determines which infected sheep will proceed to clinical disease progression is highly sought. Our laboratory is currently evaluating two different tests for the prediction or determination of OPPV clinical disease. One test is a quantitative PCR test utilizing real time technology, which targets a conserved region of the transmembrane protein of OPP provirus, and the second test is an immunogenetics test for MHC Class II DRB1. With one or both of these tests, we hope to provide a diagnostic OPPV test that determines or predicts whether the sheep will progress to OPPV clinical signs. In addition, these types of tests will significantly reduce the number of other tests necessary for determining infection and possibly lower the transmission potential in a flock. Therefore, these new tests offer significant long-term economic advantages for the producer over conventional serological diagnostic tests. BSL-1; 12-12-06. Replacing 5348-32000-025-00D, April 2007.