FMDV-host interactions mapped

Foot and mouth disease (FMDV) is endemic in many parts of the world, causing significant economic damage
Foot and mouth disease (FMDV) is endemic in many parts of the world, causing significant economic damage
Research from scientists at Oxford University and The Pirbright Institute published in Nature Communications has helped to understand the complex interaction between the foot-and-mouth-disease virus (FMDV) and host cells.
New insight into the process of interaction between the virus and host cells could lead to the development of anti-virals capable of blocking the virus from entering cells and preventing infection.
Professor Dave Stuart, Director of Life Sciences at Diamond and Director of the Division of Structural Biology at Oxford University explains: “Integrins are used by FMDV as a receptor for cell entry but until now, it has not been possible to visualise the process of engagement due the flexibility of the integrin binding portion of the viral capsid. Improved cryo-EM techniques enabled the team at Oxford University to observe the virus-host cell interaction more effectively and overcome the previous challenge of visualising the flexible attachment site.Cryo-EM allows us to rapidly study samples at very low temperatures in their natural state.”
Previous research to view FMDV at almost atomic levels of detail, revealed an exposed flexible `loop` on the surface of the otherwise smooth capsid (outer shell) - called the GH loop. FMDV infects a host cell by binding to a receptor protein on the cell surface called integrin via the GH loop.

Dr Julian Seago, Senior Scientist at The Pirbright Institute adds: “There are seven distinct serotypes of FMDV, but in this study we focussed on serotype O as it poses the most significant threat globally and is used in around 80% of vaccines. Using high resolution cryo-EM we were able to observe that FMDV extends its GH loop up and away from the virus surface to engage the integrin receptor.

“Detailed mapping of the binding mechanisms between FMDV and host cells may ultimately enable the design of new anti-virals capable of inhibiting the virus from entering host cells. Furthermore, our use of cryo-EM in this research would suggest its usefulness in studies of other virus-receptor interactions.” 
The Electron Bio-Imaging Centre (eBIC) at Diamond provides scientists with state-of-the-art experimental equipment and expertise in the field of cryo-electron microscopy, for both single particle analysis and cryo-tomography. A partnership with the University of Oxford allows users to access Polara, a high-containment cryo-electron microscope where this research was carried out.
This research forms part of a long term international collaboration including Diamond, The Pirbright Institute and Oxford University investigating FMDV, which has already led to the development of a next-generation empty capsid vaccine, amongst other successes. This work on understanding the infective process helps to uncover further information on the workings of the virus.