Molecular biology of RNA picornaviruses; protein translation, proteolytic processing; RNA synthesis; viral pathogenesis; viral vaccines, vaccine vectors; computer-based sequence analysis
We are interested in all aspects of picornavirology. Among our major goals are to explore and define the relationship of the cardiovirus genus to other members of the picornavirus family and to exploit the unique features of the cardioviruses to examine molecular questions about picornavirus translation, proteolytic processing, morphogenesis and pathogenicity. In contrast to many other viral genomes, cardioviral RNA is translated with unusually high efficiency in cell-free extracts. This provides a unique experimental system for examining viral protein expression and virion assembly. Everything we have learned about the molecular biology of these viruses provides an experimental foundation for study of the more virulent isolates such as foot-and-mouth disease virus, polio, coxsackie, hepatitis A, rhinovirus, etc. Isolates of Theiler's virus (murine encephalomyelitis), for example, and variants of EMC (encephalomyocarditis) are being studied as models in human diseases like multiple sclerosis and forms of insulin-dependent diabetes.
Our laboratory has developed an extensive panel of infectious cardiovirus cDNAs (EMC and Mengo), and we use high-tech recombinant engineering, reverse genetics and cell-free protein synthesis techniques to unravel the virus life cycle, step by step. Current projects include: 1) characterization of proteolytic agents involved in the viral protein cleavage cascade; 2) design and testing of anti-protease, anti-viral agents; 3) investigating the role of long 5' non-coding sequences (and polyC tracts) in viral translation and ribosome interactions; 4) engineered expression and isolation of non-structural proteins for enzymology and crystallography; 5) the mechanism of viral RNA replication.
Additionally, some of our genetically engineered viruses have proven to be superb live attenuated vaccines, capable of providing effective, long-lived anti-picornavirus immunity in virtually all species of mammals, including primates. We are exploiting these constructions for the prevention of picornavirus disease, but have also harnessed these agents into novel, recombinant vaccine vectors, that can deliver efficacious protection against HIV, SIV, rabies, murine malaria, and a variety of other infectious diseases. Therefore, another major research direction is the characterization of the molecular basis for viral attenuation in these cardioviruses with the objective of exploiting this phenomena and the principles to be learned from it, for the development of new and effective vaccine treatments.
We are also experimentally active in the development of computer methods for analyzing viral sequences, the prediction of the topological folding of large viral RNA genomes, computer-based visualization of virus surfaces and genomic-based virus taxonomy. We maintain widely used databases of viral protein and RNA sequences and are investigating new methods for genomic-based virus identification and taxonomy.