ARS | Publication request: Antigenic Targets of the Bovine Humoral Response to PDD-associated Spirochetes Change with Subsequent Exposure

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: September 14, 2007
Publication Date: N/A

Technical Abstract: Papillomatous digital dermatitis (PDD), also known as hairy heel wart, is a major cause of lameness of cows in the U.S. dairy industry. Cattle are known to mount a humoral response to spirochetes isolated from PDD lesions. This study was undertaken to evaluate the progression of the bovine humoral immune response to PDD-associated spirochetes. Naïve cattle were inoculated subcutaneously with a viable mixture of four (ration of 1:1:1:1) different previously isolated PDD spirochetes at two separate time points. The humoral response was evaluated by western blot. We found that sera from naïve cows contain a very low level of antibody reactive to proteins present on PDD-associated spirochetes prior to inoculation. Primary exposure elicits antibodies to a number of proteins that are distinct as well as shared between the isolates. Many of the antigens targeted in the primary response are proteinase K susceptible. Subsequent exposure elicits antibodies to LPS and proteinase K resistant proteins that appear to be similar between the isolates. These data suggest repeated exposure of cattle to PDD-associated spirochetes results in a shift in the antigenic targets of the bovine humoral response.