Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/17/2002
Publication Date: 5/20/2003
Citation: Mcholland, L. E., Mecham, J. O. 2003. Characterization of cell lines developed from field populations of Culicoides sonorensis (Diptera: Ceratopogonidae). Journal of Medical Entomology. 40 (3):348-351. Interpretive Summary: Biting midges (Culicoides) are insects that are carriers (vectors) of a number of viruses, including bluetongue virus (BLU) and epizootic hemorrhagic disease virus (EHDV). These viruses infect sheep, cattle and various species of wild ruminants. Infection of susceptible livestock and wildlife with bluetongue and epizootic hemorrhagic disease viruses results in economic loss due not only to clinical disease but also to lost trade. Research on the physical and biochemical characteristics that allow these insects to be good vectors for viruses is important in developing effective control strategies and reasonable regulations affecting livestock trade. Cell cultures provide valuable tools that can be easily manipulated experimentally to better understand what is going on in whole organisms. In this paper, we describe the development and initial characterization of cell lines from field populations of biting midges (Culicoides sonorensis). These cell lines provide tools to help us better understand how these insects transmit viruses to susceptible animals.
Technical Abstract: Two cell lines, ABADRL-Cs-W3 (W3) and ABADRL-Cs-W8A (W8), were developed from a field population of Culicoides sonorensis Wirth & Jones. The cell lines were characterized by isozyme phenotyping and the ability to support the replication of bluetongue virus (BLU) and epizootic hemorrhagic disease virus (EHDV) (Orbivirus, Reoviridae). Comparison of isozymes found in the cell lines with those found in adult C. sonorensis colony insects confirmed that the cell lines were of C. sonorensis origin. There was, however, sufficient isozyme variation present in the cell lines to construct a unique isozyme profile for each cell line. Although both cell lines supported BLU and EHDV replication to the same level, one-step growth curves indicated that virus replication was faster and attained a peak titer earlier in the W3 cell line than in the W8 cell line. Viral proteins and RNA were detected earlier in the W3 cell line as well. This suggests that this cell line may be more sensitive in Orbivirus studies.