Professor, Department of Microbiology
University of Mississippi, Jackson, Mississippi
Ph.D., Indiana University
vchinchar@microbio.umsmed.edu
My laboratory has two major research interests: viruses infecting lower vertebrates and antiviral immunity in lower vertebrates.
Viruses infecting lower vertebrates: We have focused our attention on two families of viruses. (1) Channel catfish virus (CCV, family Herpesviridae) is a major pathogen of fingerling catfish and in hatchery outbreaks leads to mortality rates approaching 100%. We have used CCV as a model to examine innate responses against virus infection. To date we have shown that channel catfish NK-like cells kill CCV-infected targets and that piscine and amphibian antimicrobial peptides rapidly inactivate CCV. Future work will involve identifying MHC-restricted cytotoxic T cell responses against CCV, and elucidating the specific targets of that response. (2) Frog virus 3 (FV3) and Ambystoma tigrinum virus (ATV) are members of the family Iridoviridae and represent a large group of viruses that include emerging pathogens among cold-blooded vertebrates. FV3-like viruses have caused high mortality among both native and cultured frogs in North America and Asia. ATV is responsible for localized die-offs of tiger salamanders throughout western North America. Our interest here is to determine viral genes important for replication and pathogenesis, and we intend to accomplish this using anti-sense technologies such as anti-sense morpholinos and siRNA. We have been aided in this task by our recent sequencing of the complete genomes of both FV3 and ATV. We thus have the tools in hand to determine the function of key viral genes involved in replication and virulence.
Antiviral Immunity in Lower Vertebrates: Our efforts here are focused on elucidating anti-viral responses in channel catfish. In this we are aided by active collaboration with our colleagues within the Department of Microbiology -- Drs. Miller, Wilson, Clem, and Bengten. We have identified anti-viral activity among catfish NK-like cells as well as several genes encoding key players in innate and acquired immunity, e.g., MHC class I, interferon, tumor necrosis factor, FasR, FADD, and caspase 8. Coupled with work by others in our department, our data indicates that catfish possess the proteins required to catalyze apoptotic cell death. We are currently in the process of expressing catfish interferon as a recombinant protein and assessing its ability to carry out various anti-viral functions in catfish cells.
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