Project Number: 1940-32000-056-03
Project Type: Reimbursable

Start Date: Oct 01, 2009
End Date: Aug 31, 2013

Objective:
Classical Swine Fever (CSF) is a highly contagious viral disease of swine. Controlling and eliminating the disease is dependant upon identification of CSF viral mechanisms involved in induction of disease generalization of infection, tissue tropism, host range, transmission, immunogenicity and strain virulence. Better understanding of these determinants will provide identification tools, vaccines and/or anti-virals. These determinants are linked to specific interactions between viral proteins with host cell proteins upon infection. To further characterize the molecular basis of CSFV and host-cell interactions ARS, PIADC and the University of Connecticut will identify swine macrophage proteins interacting with structural and non-structural CSFV proteins during infection. The effect(s) of these interactions on virulence, generalization of infection, tissue tropism, virus transmission, immunogenicity and induction of protection will be determined in swine.

Approach:
1. A Yeast Two-Hybrid screening system will be used to identify cellular proteins, using a porcine macrophage expression cDNA library, currently available at ARS, PIADC, that interact with each of the Classical Swine Fever Virus proteins. 2. The University of Connecticut will conduct fine mapping of interacting host and viral proteins to identify specific binding residues or motifs mediating the interaction. 3. Mutant viruses harboring genetically modified binding motifs will be constructed and characterized in vitro and in vivo at ARS, PIADC. Particular emphasis will be placed on establishing the ability of mutant viruses to cause disease and to induce protection in swine, relative to parental virulent virus.