Recipient Organization
CORNELL UNIVERSITY
(N/A)
ITHACA,NY 14853
Performing Department
James A. Baker Institute For Animal Health
Non Technical Summary
The purpose of our studies are to understand at a molecular level how a variety of different viruses within the Reovirus and Calicivirus families infect, replicate within their hosts and then cause disease in animals. We use a combination of molecular virology, structural studies, and cell biology to address specific questions regarding 1) the pathogenesis and cell biology of mammalian reoviruses; 2) the virulence of members of the Orbivirus genus (family Reoviridae); and 3) the role of virus-receptor interactions in the biology and pathogenesis of feline calicivirus infection and other members of the caliciviridae family. The rationale for all of these projects is the need for a better understanding of the host-virus interface, how viruses infect their hosts and the specific molecular mechanisms that they employ to subvert the hosts normal defense mechanisms. In regards, to the mammalian reoviruses, this is of benefit because these viruses are being developed as oncolytic agents in humans and there is a clear need to understand how these viruses infect cells and induce cell death. For the orbiviruses, our rationale is to develop methodologies to test hypotheses regarding the virulence of these viruses. This is important as Bluetongue virus has re-emerged as an important global pathogen for animal health and there is need of better vaccines and better understanding of how these viruses cause disease. For the caliciviruses, we use feline calicivirus as a model to understand how this family of viruses utilize cellular receptors to attach and infect cells and how differences in how these viruses interact with the receptor can determine disease outcome. This is important as although human noroviruses are the number one cause of viral gastroenteritis throughout the world, studies on these viruses is hampered by a lack of a suitable cell culture system in which to study virus-receptor interactions. There is a need for a better understanding of virus-receptor interactions in order to identify targets for therapeutic interventions.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Goals / Objectives
Reoviruses are non-pathogenic human viruses that can target and selectively kill Ras-transformed cancer cells by inducing apoptosis, while sparing untransformed cells. Because of this reoviruses are being evaluated as anti-cancer therapeutic agents. Part of this project focuses on the proapoptotic role of mu1, a viral outer capsid protein. There are three specific aims: 1) To identify the specific region(s) of the mu1 protein that is responsible for inducing apoptosis. 2) To determine the mechanism(s) by which the mu1 protein induces apoptosis in transfected cells and to assess its contribution to apoptosis induction in infected cells during viral replication. 3) To identify the specific cellular apoptotic pathways(s) activated by the mu1 protein. These studies should provide significant insights into the mechanisms of reovirus-induced apoptosis and may lead to improved applications of reoviruses as anti-tumor agents. The mammalian reoviruses are double-stranded RNA viruses that have long been used to study basic mechanisms of viral replication and pathogenesis. New virions assemble in specific cytoplasmic structures called viral factories (VFs). Our long-term goals are to understand how VFs function to promote viral replication and assembly. The specific aims of this part of the project are: 1) To identify cellular proteins associated with VFs and explore their role(s) in viral replication. 2) To determine the sites of assembly and mechanisms of recruitment of reovirus outer capsid proteins to VFs. 3) To characterize the dynamics of VF formation and destruction. Orbiviruses are insect-borne infectious agents of ruminants that cause economically important disease in Israel and the United States. Long-term goals of this part of our project are to identify the specific viral determinants responsible for virulence, growth and transmission of the orbiviruses Bluetongue virus and epizootic hemorrhagic disease virus (EHDV). The goals are (i) to create plasmid-based reverse genetics systems for BTV-17 and EHDV2-Ibaraki; and (ii) to identify the molecular determinants of the NS3 nonstructural protein responsible for its viroporin activity (see preliminary findings). New isolates of feline calicivirus (FCV) cause severe life-threatening virulent systemic (VS) disease. VS-FCV isolates differ from non-VS isolates in their tissue and cell tropism, infecting epithelial and endothelial cells in several different organs. Our long-term goals are to understand the relationship between FCV-receptor interactions and viral tropism, and to identify what role these interactions play in FCV virulence. The goals of this part of the project are to determine the role that glycans play in determining the cell tropism of different FCV isolates and to identify the range of different glycans that FCV isolates can bind.
Project Methods
This project utilizes many different scientific methods that include a broad variety of techiques used in molecular virology, structural biology, cell biological studies of viral infection, protein biochemistry and proteomics. We also viral genetics both forward and reverse to identify and genetically classify viral phenotypes. Data generated is analyzed using standard statistical approaches.