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ARS Home » Northeast Area » Orient Point, New York » Plum Island Animal Disease Center » Foreign Animal Disease Research » Research » Research Project #434404

Research Project: Development of a Next-Generation African Swine Fever Vaccine using Bioinformatic Analysis of Circulating Strains in Uganda

Location: Foreign Animal Disease Research

Project Number: 8064-32000-060-20-N
Project Type: Non-Funded Cooperative Agreement

Start Date: Sep 1, 2018
End Date: Aug 31, 2020

Objective:
This research project will provide scientific information and countermeasures to control and eradicate African Swine Fever Virus (ASFV) for which there are no commercial vaccines. The primary target profile for African Swine Fever (ASF) vaccines includes a rapid onset of immunity and prevention of transmission. This research project will utilize functional characterization and bioinformatics to identify virus-host determinants of virulence and transmission, identify genes which can be manipulated to induce the immune response for vaccine development, and conduct genotyping for ASFV strains circulating in Africa. Specific objectives include: 1. Develop and assess next generation candidate ASFV vaccines using bioinformatics to determine additional genetic determinants of virulence in ASFV. 2. Assess the host response to candidate ASFV vaccine by utilizing next generation sequence (NGS) technology to determine the differences in RNA expression profile of host target cells. 3. Assess current circulating ASFV strains in Uganda by obtaining and sequencing by NGS field isolates from Uganda.

Approach:
1. To develop intervention strategies to control ASFV, including identification by functional genomics of virus-host determinants of virulence and transmission, determination of host mechanisms of ASF immune protection, and discovery of effective ASF vaccine platforms specifically designed for disease control and eradication activities include: (i) identify and characterize novel virus genetic determinants of virulence in swine; (ii) rationally develop safe and effective vaccine virus strains by incorporating the new generic determinants of virulence into our previously developed experimental vaccine strain ASFV-G-delta9GLdeltaUK. 2. An evaluation of the RNA expression profiles in swine cells infected with attenuated or virulent strains of ASFV will be conducted. The primary cell infected by ASFV is the swine macrophage. Macrophages isolated from swine blood have been shown to support ASFV growth, with close to 100% infected when a high titer of ASFV is used. For this objective the RNA expression profile differences between vaccine and virulent strains of ASFV will be determined. Macrophages will be infected, and RNA will be collected and analyzed by NGS using RNA sequence. Responses of macrophages from three different animals will be assessed to allow for discrimination of inter-animal variation. The RNA expression profile will be compared between cells infected with vaccine or virulent strains to determine how the host responds differently to virulent ASFV vs attenuated ASFV. The results will support the identification of immune correlates of protection needed for future experimental and field trials to identify effective ASFV vaccines. 3. Previous analysis has shown that the genomes revealed less conserved patterns among African viruses than European and American viruses. In addition to virus variation, the environmental, vector, animal demographic, and animal management factors that drive ASF emergence, re-emergence and spread in different areas of Africa, including Uganda, are not known. We will begin to address these key gaps in understanding of ASF by determining by NGS full-length genome sequencing of currently circulating strains in Uganda.