Saliva Proteins of Vector Culicoides Modify Structure and Infectivity of Bluetongue Virus Particles

Scientists at the Institute for Animal Health in Woking, United Kingdom, have discovered a novel mechanism by which proteases in Culicoides saliva can modify the structure and infectivity of bluetongue virus particles. The researchers found that saliva proteins from adult Culicoides, a haematophagous midge vector, can cleave the larger outer-capsid protein, VP2, of bluetongue virus, resulting in enhanced infectivity for adult Culicoides. This discovery has significant implications for our understanding of the transmission dynamics of bluetongue virus and the role of Culicoides in spreading the disease.

Key Takeaways:

• The researchers found that saliva proteins from adult Culicoides can cleave the larger outer-capsid protein, VP2, of bluetongue virus.
• The cleavage of VP2 results in enhanced infectivity for adult Culicoides, suggesting a novel mechanism of transmission for bluetongue virus.
• The protease content in Culicoides saliva, dependent on the vector species, can influence the efficiency of VP2 cleavage and virus infectivity.
• The study found that temperature, strain of virus, and protein composition of Culicoides saliva can all play a significant role in the efficiency of VP2 cleavage.
• The discovery has significant implications for our understanding of the transmission dynamics of bluetongue virus and the role of Culicoides in spreading the disease.

Statistics:

• The study found that the saliva proteins from C. sonorensis cleaved BTV-VP2 more efficiently than those from C. nubeculosus.
• The researchers observed a 10-fold increase in infectivity for KC cells after incubating purified BTV-1 with C. sonorensis saliva proteins.
• Infectivity for BHK cells was reduced by 2-6 fold after treatment with C. sonorensis saliva proteins.

Sources:

• Darpel, K.E., et al. "Saliva proteins of vector Culicoides modify structure and infectivity of bluetongue virus particles." Plos One, 2011; 6(3): e17545.