Tick-borne encephalitis (TBE), caused by the tick-borne encephalitis virus (TBEV), is a disease manifested by severe inflammation in the central nervous system, which may be fatal. Even though vaccination is available, only approximately 23% of Czech population has received it [1]. No targeted treatment is presently available for TBE, yet with cases continually rising the urge for one is ever-growing. This is where antibodies could be of use – it has previously been shown in a mouse model that an intravenous admission of TBEV-specific antibodies could serve as a treatment [2]. However, insight into the molecular mechanisms of TBEV neutralisation is limited.
Therefore, we studied the interactions between the TBEV strain Neudörfl and two neutralising mouse monoclonal antibodies, IC3 and A4, each binding to a different domain of the TBEV envelope protein [3]. TBEV was purified from infected tissue culture cells, mixed with Fab fragments prepared from the neutralising antibodies, and vitrified on grids for cryo-electron microscopy. Structures of the TBEV–Fab complexes were then solved using single particle analysis from the collected micrographs.
Deciphering the molecular basis of TBEV neutralisation by antibodies might aid with understanding the importance of different epitopes on the viral surface, possibly enabling tailored design of therapeutic antibodies or more specific vaccines in the future.
This project has been realised with the financial support of the Grant agency of Masaryk university within the Student research support program, project No. MUNI/C/0032/2022