Submitted to: Veterinary Immunology and Immunopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2009
Publication Date: 8/1/2009
Publication URL: http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TD5-4VNH3P6-1-5&_cdi=5189&_user=4250360&_orig=search&_coverDate=02%2F20%2F2009&_sk=999999999&view=c&wchp=dGLbVzz-zSkzk&md5=771143ed20313a4ee6d2259f33ebd596&ie=/sdarticle.pdf
Citation: Elliott, M.K., Alt, D.P. 2009. Bovine Immune Response to Papillomatous Digital Dermatitis (PDD)-associated Spirochetes is Skewed in Isolate Reactivity and Subclass Elicitation. Veterinary Immunology and Immunopathology. 130(3-4):256-261. Interpretive Summary: Papillomatous digital dermatitis (PDD), also known as hairy heel wart, is a growing cause of lameness of cows in the U.S. dairy industry. PDD causes a significant loss of revenue for dairy farmers worldwide. Little is know about the immune response of cattle to spirochetes found in PDD lesions. In this study, we evaluated the level and type of antibodies produced by test cattle to PDD-associated spirochetes. We found that when test cattle are exposed to four different spirochetes in equal numbers, the antibody response to each spirochete is not equal. When the test cattle received a second exposure, the spirochete against which the highest level of antibodies was produced changed, resulting in a reactivity profile similar to that seen in field cattle naturally exposed to PDD-associated spirochetes on the farm. IgG1 was the type of antibody produced at the highest level to all the spirochetes in both test and field cattle. Understanding the immune response of cattle to PDD-associated spirochetes is important in the development of vaccines for PDD in cattle.
Technical Abstract: Papillomatous digital dermatitis (PDD), also known as hairy heel wart, is a growing cause of lameness of cows in the U.S. dairy industry. Farms with PDD-afflicted cows experience economic loss due to treatment costs, decreased milk production, lower reproductive efficiency and premature culling. Cows have been shown to mount both humoral and cellular responses to PDD-associated spirochetes. This study was undertaken to further characterize the bovine humoral response to PDD-associated spirochetes. Forty-seven sera samples collected from cattle (field cattle) on 3 different dairy operations in Iowa between the years of 1999 and 2001 were analyzed. In addition, sera were obtained from six young steers (test cattle) that had been exposed to a mixed inoculation of four previously isolated Treponema phagedenis-like spirochetes (1A, 3A, 4A and 5B) on two separate occasions. Total IgG, IgG1, IgG2 and IgM reactivity of the sera to each individual spirochete was measured. Field cattle had a higher mean antibody response to 5B when compared to the other isolates and T. phagedenis. Test cattle reacted most strongly with 4A following initial exposure shifting to a higher reactivity with 5B and a reactivity profile similar to field cattle following secondary exposure. No measurable IgM was detected in any sample. IgG1 was produced predominately in all cattle. Low to moderate levels of total IgG reactivity to T. phagedenis occurred with sera from both groups of cattle.