Carol D. Blair
Professor
Phone: 491-8243
Fax: 491-8323
Email:
Carol.Blair@Colostate.Edu
Office: 107 Arthropod-borne and Infectious Disease Lab
Lab: Arthropod-borne and Infectious Disease Laboratory, Foothills Campus
Degrees
B.A. University of Utah, Microbiology
Ph.D. University of California, Berkeley, Molecular Biology
Research Interests
Molecular Virology
Our research interests at the Arthropod-borne and Infectious Diseases Laboratory focus on the molecular biology of interactions between arthropod-borne viruses (arboviruses) and their mosquito hosts. We are particularly interested in the molecular genetic mechanisms that determine the ability of arboviruses to establish persistent, noncytocidal, life-long infections in mosquitoes even though they can cause serious disease in vertebrate hosts. We are exploring these relationships in several different systems.
Dengue (DEN) viruses, serotypes 1-4, are Flaviviruses that annually cause at least 100 million human infections throughout the tropical range of their principal vector, Aedes aegypti. We were first to show that a major component of the mosquito innate immune response, RNA interference (RNAi), can be enhanced to block DENV infection of mosquitoes. Natural DENV2 infection of Ae. aegypti adult mosquitoes triggers the RNAi response, but replication and release of infectious virus persists, suggesting viral circumvention of RNAi. We are currently investigating both the molecular components and mechanisms of RNAi and the means of viral evasion of this important mosquito immune response. Our ultimate goal is to devise new strategies to interrupt transmission of DENV by Ae. aegypti.
West Nile virus (WNV), also a Flavivirus, has become established as a major arboviral pathogen throughout the US since its introduction in 1999. Members of the Culex genus are important mosquito vectors of WNV. We have collected mosquitoes in Colorado since 2003 to examine spatial and seasonal patterns of risk for exposure to Culex vectors and WNV. Using universal flavivirus primers to test Culex tarsalis and Cx. pipiens pools for WNV RNA led us to the detection and subsequent isolation of two insect-specific flaviviruses, one that is similar to viruses recently described from Japan, and a novel insect flavivirus, which has a genome sequence similar to Flaviviruses detected in Culex spp. in California and Canada. These viruses persistently infect mosquitoes but are not transmitted to vertebrates. We are investigating the effects of natural co-infections with these newly-discovered viruses on the ability of Culex spp. to transmit WNV.
Selected Publications
Pub Med for Blair CD.
Sánchez-Vargas, Irma, Jaclyn C. Scott, B. Katherine Poole-Smith, Alexander W. E. Franz, Valérie Barbosa-Solomieu, Jeffrey Wilusz, Ken E. Olson, and Carol D. Blair. 2009. Dengue Virus Type 2 Infections of Aedes aegypti are Modulated by the Mosquito’s RNA Interference Pathway. PLoS Pathogens, 5(2): e1000299.
Keene, Kimberly M., Brian D. Foy, Irma Sánchez-Vargas, Barry J. Beaty, Carol D. Blair, and Ken E. Olson. 2004. RNA interference acts as a natural antiviral response to O’nyong-nyong virus (Alphavirus; Togaviridae) infection of Anopheles gambiae. Proc. Natl. Acad. Sci. USA, 101 (49), 17240-17245.
Blair, C. D., Z.N. Adelman, and K. E. Olson. 2000. Molecular strategies for interrupting arthropod-borne virus transmission in mosquitoes. Clinical Microbiology Reviews, 13, 651-661.
Olson, K.E., S. Higgs, P.J. Gaines, A.M. Powers, B. S. Davis, K.I. Kamrud, J. O. Carlson, C. D. Blair, and B.J. Beaty. 1996. Genetically engineered resistance to dengue-2 virus transmission in mosquitoes. Science 272:884-886.