Email: Office Phone: 318-675-8148
Laboratory Phone: 318-675-8149
Office Fax: 318-675-5764
Postdoctoral Study, Washington University School of Medicine
Ph.D Microbiology, 1999, University of Kansas
B.S. Pharmacy, 1993, University of Kansas
Major Research Interests:
Pathogenesis of oncogenic viruses, virus-host interactions, host immunity to viruses, viral latency.
Gammaherpesviruses such as Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) are associated with multiple diseases in humans, including lymphomas, carcinomas, and Kaposi's sarcoma. Murine gammaherpesvirus 68 (gammaHV68) is genetically related to EBV and KSHV and causes lymphoma in mice, providing a small animal model for mechanistic in vivo studies of the virus/host relationship. Gammaherpesviruses evade the antiviral immune response by establishing a semi-dormant state called latency, facilitating life-long infection of the host. Work in our laboratory is focused on dissecting the central role of latency in viral pathogenesis. To facilitate these studies, we have generated mutant viruses that cannot lytically replicate but that may establish latency. Using these viruses, we are defining the viral genes that are expressed during latency and determining their specific roles in both the viral life cycle and in modulating host immunity. The long-term goal of these studies is to better understand the interplay between the antiviral immune response and latency, and to define how alterations in this relationship can result in the development of lymphoma.
Tibbetts, S., van Dyk, L., Speck, S., Virgin, H. 2002. Immune control of the number and reactivation phenotype of cells latently infected with a gammaherpesvirus. J. Virol. 76:7125-7132.
Tibbetts, S., McClellan, J., Gangappa, S., Speck, S., Virgin, H. 2003. Effective vaccination against long-term gammaherpesvirus latency. J. Virol. 77:2522-2529.
Tibbetts, S. *, Loh, J.*, van Berkel, V., Kapadia, S., McClellan, J., Jacoby, M., Speck, S., Virgin, H. 2003. The establishment and maintenance of gammaherpesvirus latency is independent of infective dose. J. Virol. 77:7696-7701. [*authors contributed equally to this work]
McClellan, J., Tibbetts, S., Gangappa, S., Brett, K., Virgin, H. 2004. Critical role of CD4 T cells in an antibody independent mechanism of vaccination against gammaherpesvirus latency. J. Virol. 78:6836-6845.
Tarakanova, V., Suarez, F., Tibbetts, S., Jacoby, M., Weck, K., Hess, J., Speck, S., and Virgin, H. 2005. Murine gammaherpesvirus 68 infection induces lymphoproliferative disease and lymphoma in BALB beta2 microglobulin deficient mice. J Virol. 79:14668-14679.
Steed, A., Barton, E., Tibbetts, S., Popkin, D., Lutzke, M., Rochford, R., Virgin, H. 2006. Interferon gamma blocks gammaherpesvirus reactivation from latency. J Virol. 80:192-200.
Braaten, D., McClellan, J., Messaoudi, I., Tibbetts, S., McClellan, K., Nikilich-Zugich, J., and Virgin, H. 2006. Effective control of chronic gammaherpesvirus infection by unconventional MHC Class Ia-independent CD8 T cells . PLOS Pathogens. 2(5):e37.
Tibbetts, S., Suarez, F., Virgin, H. 2006. A replication-defective gammaherpesvirus establishes chronic infection in vivo and is impervious to T and B cell restriction. Virology. 353:210-219.