Location: Foreign Animal Disease Research
Project Number: 8064-32000-056-13-R
Project Type: Reimbursable
Start Date: Mar 30, 2012
End Date: Dec 31, 2015
This research project seeks to address the threat of an introduction and subsequent outbreak of African Swine Fever (ASF) into the United States through a comprehensive research program aimed at countermeasure development. Specific objectives include: 1. Development of challenge model for ASF to characterize pathogenesis and evaluate novel countermeasure products. 2. Determine the immune mechanisms of protection induced by attenuated strains. 3. Determine the role of viral proteins in virulence/ pathogenesis/ protection through functional genomic analysis. Amendment 3 will provide initial funding for start up activities for objectives 4 and 5 . These objectives will be completed upon subsequent funding. 4. Development of ASFV live attenuated vaccines be deleting several virus genes involved in virus virulence. 5. Development of ASFV subunit vaccine co-expressing several viral proteins using modified virus Ankara (MVA) as vector.
1. The development of a challenge model for ASF will be accomplished through challenging pigs with virulent ASFV via different routes (oral, nasal, and intramuscular) and at varying doses. The goal is to develop a system of viral challenge that accurately simulates natural infection. Model efficacy will be evaluated by characterizing viral dynamics in live animals and post-mortem samples. 2. The immune response to challenge with attenuated strains will be determined by analyzing the onset of protection. Comparative studies will be conducted using virulent and attenuated stratins focusing on temporal, anatomic and phenotypic characterization of ASFV distribution. Pro-inflammatory chemical mediators will be analyzed and cytotoxic T lymphocyte activity studied to determine mechanisms of immune response. 3. Bioinformatic analysis will be conducted on ASFV proteins to determine their role(s) in virulence/pathogenesis/ protection. Further analysis will be conducted to determine the host–virus interaction at the genomic level using microarray technology. Amendment 3: 4. Using the ASFV strain Georgia 07 as the parental virus, multiple gene deletions will be sequentially made in order to stabilize the attenuated phenotype. Sequential deletions will be performed by homologous recombination following methodologies previously developed by ARS, PIADC. In the initial stage we will finish the transfections inititated in project HSHQDC-11-X-00077 (ARS 60-1940-1-039) in order to produce the first generation of recombinant ASFV lacking virulent associated genes. It is expected to significantly advance the process of virus purification. 5. Recombinant MVA vectors will be designed and constructed by a series of homologous recombination procedures which would allow the sequential incorporaton of different ASFV genes based in the information produced in project HSHQDC-11-X-00077. It is expected to advance the recombination process in order to obtain recombinant MVA and to initiate the process of purification.