2012 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.
This is a trust agreement which was initiated in 2007 with Seppic Inc. in France to develop molecular vaccines against avian coccidiosis and necrotic enteritis (NE). Due to the increasing regulations and bans on the use of antibiotics growth promoters (AGPs), there is an urgent need to develop alternative control strategies for infectious diseases of poultry where conventional vaccines show limitations. In previous reports, ARS scientists in Beltsville, MD demonstrated that the 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. Eimeria profilin, which is highly conserved across different stages of Eimeria life cycle and multiple Eimeria species such as E. tenella and E. maxima, was used. During this reporting period, nanoparticle-based (IMS 1313) and oil-based (ISA71) adjuvants were investigated in combination with an Eimeria subunit protein vaccine for protection against avian coccidiosis. Birds vaccinated with profilin plus ISA 71 had increased body weight gains compared with the profilin-only control group. Immunization with either profilin plus IMS 1313, or with profilin plus ISA 71, reduced fecal oocyst shedding compared with the profilin-only group. Furthermore, immune parameters such as the percentages of intestinal lymphocytes showed enhanced indication of protection against coccidiosis. Collectively, these results demonstrate successful induction of protective immunity against avian coccidiosis in broiler chickens using the recombinant profilin subunit vaccine in conjunction with IMS 1313 or ISA 71 adjuvants.