Objective:
The objective of this project is to develop the basic knowledge and molecular tools necessary to dissect the quality of immune response to infection and vaccination with Foot-and-Mouth Disease Virus in cattle. Specific objectives include: 1. Develop technologies and reagents necessary to assess the humoral and cytokine immune response components in bovine. 2. Determine T-cell responses to FMDV infections and to viral antigens. 3. Determine respective roles of the humoral and cellular immunity in the protective immune response against FMDV induced by immunization with Adenovirus vectors or similar subunit vaccines or combinations of vaccine, adjuvants and antivirals. 4. Develop assays to determine the role and function of dendritic cells resident in the lung during FMDV infection and following vaccination against FMDV.

Approach:
Efforts will be focused in two major areas. 1. Development of reagents and of technologies to detect and characterize the quality of humoral and cytokine components of immune responses to FMDV in cattle. 2. Applying those reagents and techniques in determining the T-helper dependence of the bovine immune response to FMDV antigens. 3. Demonstrating the role of the lung dendritic cells in vaccinated and infected cattle. Cattle will be inoculated with purified live or inactivated virions, or with Adenovirus vectors containing FMDV antigens, with or without adjuvants and antivirals. Their cytokine and serological responses will be monitored through the use of real-time PCR or immunoassays. Some animals will be necropsied at 24 to 72 hours after infection of challenge of vaccinated animals to harvest lung and associated lymphoid tissue for analysis of the activation and function of dendritic cells resident in these tissues. Based on this information, we will develop vaccine formulations or modified existing ones for rapid induction of protective immunity. We will compare the humoral and cellular immune responses to FMDV infections in bovine host and monitor the role of specific subsets of T and B cells using specific markers and flow cytometry. UTMB will develop reagents such as monoclonal antibodies and assays to determine the quality and quantity of serum antibody responses to FMDV after infections and/or antigen inoculations. UTMB will develop technologies, such as real-time RT-PCR and enzyme immunoassays, to assay T-helper cell responses and real-time flow cytometric assays for cytokine production. ARS will determine the pathogenesis of FMDV in cattle, such as antigen distribution and correlate with local and systemic immune responses. Assays of dendritic cells in the respiratory and mucosal regions will be developed. All experiments in cattle, requiring infectious FMDV will be conducted at PIADC.