Biotyping of TBEV-infected IRE/CTVM19 tick cell line

Background. Ticks have developed defense mechanisms and pathways against transmitted infections, including tick-borne encephalitis virus (TBEV). An important issue is to reveal mechanisms allowing them to control the virus at a level which does not hinder ticks’ fitness and development.

Methods. Biotyping was performed on an Autoflex Speed MALDI-TOF/TOF (Bruker Daltonik). Protein digests were analyzed using Synapt G2-Si High Definition mass spectrometer (Waters).

Results. MS profiles of TBEV-infected and non-infected IRE/CTVM19 cells were analyzed using principal component analysis. Obtained spectra were clustered based on the cultivation time, but not the infection status. Nevertheless, analysis of loading plots revealed different factors to be important for clustering of infected and non-infected cells. Out of them, nine were assigned with proteins: five and four for non-infected and infected cells, respectively. Peak with m/z 8565 was found to be of interest from viewpoint of tick-virus interaction and assigned to proteasome subunit alpha type (B7QE67).

Conclusion. MALDI-TOF MS was shown to be useful for characterization of tick cell lines and studying tick-virus interactions. Signals in MS profiles discriminating cell aging and those affected by TBEV were revealed, and matched with proteins.

We thank Dr Lesley Bell-Sakyi and the Tick Cell Biobank for provision of IRE/CTVM19 cells.

This study was supported by the MŠMT ČR INTER-ACTION project (LTARF 18021); GAČR (18-27204S), European Regional Development Fund Project (CZ.02.1.01/0.0/0.0/15_003/0000441), and MSHE RF (#14.616.21.0094, RFMEFI61618X0094). Access to instruments and other facilities was supported by the Czech research infrastructure for systems biology C4SYS (LM2015055).