Location:
Project Number: 8064-32000-061-028-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jul 1, 2016
End Date: Jun 30, 2019
Objective:
This research project seeks to develop prophylactic products that target pre-viremic events in the pharynx and lungs and gain an understanding of the induction of respiratory mucosal immunity against Foot-and-Mouth Disease Virus infection in cattle.
Specific objectives include:
1. Assess the role of the systemic antibody response in naïve calves immunized by passive transfer of anti-FMDV antibodies obtained from vaccinated cattle.
2. Assess the role of local immunity in calves previously infected by aerosol with recombinant virus developed by ARS, PIADC which presents a replication pattern restricted to the respiratory tract.
Approach:
1. Cattle will be infected using FMDV 01 Campos delta 3A to generate animals carrying only local immunity. Eight cattle will be infected via the oronasal route and euthnized at 7, 14, 21 and 28 days post infection. Necropsies will be conducted to determine the induction of anti-FMDV adaptive immune response.
2. Cattle will be assessed for response to recombinant FNFV 01 Campus using anti-FMDV ASC ELISpot. Infected cattle will be analyzed up to three weeks after infection. Time-points for re-infection will be determined, and serum and whole blood sampling will be conducted to detect circulating viral RNA. Specific FMDV T-cell responses will be determined by ELISA testing.
3. Cattle previously infected by the oronasal route with 01 Campus delta 3A will be re-infected using virulent wild-type FMDV O1 Campos. Serum and blood samples will be collected to determine viremia. In addition, serology assays will be performed to further characterize the humoral systemic responses. Information obtained will compared with those of the bovines only infected with recombinant 01 Campus delta 3 A to assess induction of memory responses.
4. Naïve cattle will be vaccinatd using commercial high payload tetravalent FMD vaccines including O1 Campus strain. Serum will be collected at 7 and 30 days post vaccination. Passive transference studies will then be conducted on naïve steer to determine if antibodies have been passively acquired.
5. Passive immunized steers will be infected after transference by controlled aerogenous adminstraton of virulent FMDV 01 Campos. Asymptomatic animals will be kept until 7 days post-infection and assessed ifor ASC response in different lymphoid organs.
