Submitted to: Journal of General Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 25, 1997
Publication Date: August 25, 1997
Citation: Xu, G., Wilson, W.C., Mecham, J.O., Murphy, K., Tabachnick, W.J. 1997. Vp7: an attachment protein of bluetongue virus for cellular receptors in culicoides variipennis. Journal of General Virology. 78:1617-1623.
Interpretive Summary: Bluetongue virus is the causative agent of disease in sheep and cattle and has resulted in international trade restrictions. The movement or transmission of this virus from animal to animal requires a biting insect intermediary. The protein that the virus uses to attach to the cells of the insect that transmits the virus was identified. This will allow the development of novel disease control strategies.
The importance of VP7 of bluetongue virus (BTV) in the binding of BTV to membrane proteins of the BTV vector Culicoides variipennis was investigated. Core BTV particles, prepared from whole viruses, lacked outer proteins VP2 and VP5 and had VP7 exposed. More core particles and whole viruses bound to membrane preparations of adults of C. variipennis and KC cells, which were cultured from this vector insect, than to membrane preparations of Manduca sexta larvae. More core particles than whole viruses bound to membrane preparations of adults of C. variipennis and KC cells. Polyclonal anti-idiotypic antibodies (anti-Id), which were made against an antigen-combining region of an anti-BTV-10 VP7 antibody and functionally mimicked VP7, bound more to the membrane preparations of adults of C. variipennis and KC cells, and less to cytosol preparations. In Western overalay analysis, the Culicoides plasma membrane preparation reduced binding of an anti-VP7 monoclonal antibody to VP7. Whole and core BTV particles and the anti- Id bound to a membrane protein with a molecular mass of 23 kDa that was present predominantly in membrane preparations of adults of C. variipennis and KC cells. This protein was present in much lower concentrations in membrane preparations of C6/36 and DM-2 insect cells.