Prophylactic Vaccine Against Mycobacterium paratuberculosis in Cattle

Johne's disease, a chronic granulomatous enteritis of cattle is the result of infection with the extremely slow growing bacillus Mycobacterium paratuberculosis. It is estimated that 20-30% of U.S. dairy and cattle herds are infected with this organism with resulting combined losses to the dairy and beef industries estimated to be between $200 million and $1 billion per year. Current vaccine strategies utilizing non-viable mycobacteria have proven to be largely ineffective and are currently permitted in only 3 states. We further hypothesize based on our extensive experience with murine models of mycobacteria infection, that successful vaccines must incorporate proteins contained within the Culture Filtrate (CFP) extracted from the supernatant of mycobacteria during the log phase of growth. We propose here to vaccinate several small groups of cattle with mixtures of M. paratuberculosis CFP emulsified into adjuvants which have been demonstrated to promote a T helper Type 1 (TH1) immune response; experimentally infect these animals for the emergence of T cell populations previously associated with protection. Animals will be analyzed for DTH response. T cell production of IFN-g, and circulating memory T cell phenotype expression.