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United States Department of Agriculture

Agricultural Research Service

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Location: Foreign Animal Disease Research

2013 Annual Report

1a. Objectives (from AD-416):
The objective of this research project is to evaluate native and modified forms of Classical Swine Fever (CSF) envelope proteins for their capacity to induce rapid protective immune responses against CSF virus.

1b. Approach (from AD-416):
The protective efficacy of the three virus envelope glycoproteins E0, E1 and E2 will be assessed in swine. Native forms of E0, E1 and E2, as well as harboring modifications that may enhance their immunogenicity, will be expressed in the baculovirus system and assessed in their ability to induce early protection within the first week after immunization. Modifications to the E0, E1 and E2 structure will include their fusion with immunostimulatory molecules (flagelin), or their ability to deliver to professional antigen presenting cells by fusing them to anti-class II antibodies or by increasing their immunogenicity by expressing them as highly complexed molecules to tetramers. It is expected that the introduced modifications would improve the efficiency of these candidate vaccines.

3. Progress Report:
The goal of this grant to develop intervention strategies to control and eradicate Classical Swine Fever Virus (CSFV) and to develop effective CSFV vaccines and diagnostic platforms. The first part of this project consisted in the assessment of the immunogenicity of the native version of virus structural glycoproteins E0, E1 and E2. Recombinant baculoviruses were produced, the different proteins expressed and purified and their immunogenicity successfully evaluated in terms of the elicited immune response and protection when inoculated in swine. The second part of the project considers the expression of modified version of those proteins and evaluate if an enhance of their immunogenicity is achieved by the modifications. Recombinant baculovirus containing the modified proteins were produced and expression of the proteins performed. Levels of the expressed proteins are not satisfactory as well as the amount of purified proteins obtained. During FY 2013 different methodologies were applied in order to solve these technical problems and optimize the expression of the recombinant modified version of these proteins. All proteins were at the end expressed and purified and the preliminary experiments to evaluate their immunogenicity in swine were performed. Results obtained showed no significant differences in the antibody response elicited by the native vs. modified version of the glycoproteins. New immunization experiments will perform evaluating a range of different doses of the immunogenic proteins. This grant ended in FY 2013. No technologies were transferred. No publications were produced in FY 2013.

4. Accomplishments

Last Modified: 07/26/2017
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