2011 Annual Report
1a.Objectives (from AD-416)
To evaluate the adjuvant effects of Seppic's immunomodulators in poultry immune system.
1b.Approach (from AD-416)
Broiler chickens will be treated with Seppic's immunomodulators and the effects on avian immune response to mucosal pathogens will be evaluated using established disease parameters and various immunological assays.
Due to the increasing regulations and bans on the use anticoccidial drugs, we are trying to develop alternative control strategies for enteric disease control including recombinant protein, subunit, live-vector or DNA vaccination. Accumulating evidence indicates that weak immunogenicity of currently used subunit vaccines against many infectious diseases of livestock and poultry increases production costs and fails to effectively curtail disease outbreaks. In our previous report, we demonstrated that Montanide™ series adjuvants when combined with recombinant Eimeria antigens afforded significant protection against a high-dose, oral challenge infection with live sporulated E. acervulina oocysts. We used Eimeria profilin which is highly conserved across different stages of Eimeria life cycle and multiple Eimeria species such as E. tenella and E. maxima. The previous study that we conducted using Montanide™ series adjuvants resulted in only partial protection against challenge infection as fecal oocyst shedding was unaffected by vaccination with profilin plus ISA 70 VG compared with profilin alone. In the present report, broiler chickens were immunized subcutaneously with a purified Eimeria acervulina recombinant profilin protein, either alone or mixed with ISA 71 VG. Vaccination with profilin plus ISA 71 VG reduced oocyst shedding compared with animals immunized with profilin alone. These results demonstrate that the recombinant profilin subunit vaccine, when given in combination with Montanide™ ISA 71 VG, augments protective immunity against E. acervulina and E. tenella. Using novel immunoadjuvant formulation to elicit cell-mediated immunity is important for recombinant vaccination strategy against many poultry diseases where conventional methods have proven to be ineffective. Work progress is monitored by regular teleconferences, meetings and formal written progress reports.