|
|
Tick-borne encephalitis virus inhibits rRNA synthesis and host protein production in human cells of neural origin
SELINGER, Martin
Tick-borne encephalitis virus (TBEV), a member of the genus Flavivirus (Flaviviridae), is a causative agent of a severe neuroinfection. Recently, several flaviviruses have been shown to interact with host protein synthesis. In order to determine whether TBEV interacts with this host process in its natural target cells, we analysed de novo protein synthesis in a human cell line derived from cerebellar medulloblastoma (DAOY HTB-186). We observed a significant decrease in the rate of host protein synthesis, including the housekeeping genes HPRT1 and GAPDH and the known interferon-stimulated gene viperin. In addition, TBEV infection resulted in a specific decrease of RNA polymerase I transcripts, 18S and 28S rRNAs and their precursor, 45-47S pre-rRNA, but had no effect on the RNA polymerase III-transcribed 5S rRNA levels.
|
|
|
Molecular Factors of Cell Antiviral Immunity
SELINGER, Martin
The proposed thesis focuses on the description of flavivirus-host interactions in case of tick-borne encephalitis virus (TBEV) and Zika virus (ZIKV). In more detail, the TBEV-induced host responses in human cells of neural origin and interferon-mediated protection were described together with the identification of a new phenomenon of TBEV-induced host transcriptional and translational shut-off. In addition, virus-derived molecules with hypothetical immunomodulatory characteristics, TuORF and ZIKV sfRNA, were analysed for their presence and possible function during the infection.
|
|
|
Studium exprese cílových mRNA při pospiviroidní patogenezi v systému "leaf factory"
SELINGER, Martin
The aim of this work was to identify potential mRNA targets of PTGS triggered by viroid-derived small RNAs (vsRNAs) in PSTVd-infected tomato plants (S. lycopersicum L.). We selected 47 possible gene targets using data provided by Prof. Dr. Steger (Heinrich Heine Universität, Düsseldorf, Germany) - the list of 1633 possible target mRNAs from tomato based on vsRNA:mRNA duplex prediction. The vsRNA sequences were obtained by Illumina sequencing of small RNA libraries from healthy and PSTVd-infected tomato plants. By qRT-PCR analysis we identified 6 genes with significantly altered levels of mRNA in PSTVd-infected tomato plants: CUL1 (protein ubiquitination), ERF4 (transcription factor of abiotic stress signalling pathway), H/ACA1 (rRNA pseudouridylation), NPH3 (transcription factor of fototropic signalling pathway), Sl-MYB (transcription factor regulating leaf development) and TCP3 (transcription factor regulating leaf development). The binary vector pLV07 with inserted expression cassette containing coding sequence of Sl-MYB was prepared for experiments in ?leaf factory? system in N. benthamiana plants. Expression analyses in ?leaf factory? system after 1,5 DPI using qRT-PCR and RNA blots revealed strong inhibition of expression of Sl-MYB in leaf sectors infiltrated with severe PSTVd AS1 strain, while mild PSTVd QFA strain showed minimal change in expression comparing to control sectors. Moreover, the overexpression of Sl-MYB in leaf sectors resulted in development of necroses after 2,5-3 DPI, in presence of silencing suppressor p19 after 2 DPI. The development of necroses was largely inhibited in PSTVd AS1-infiltrated leaf sectors in comparison with PSTVd QFA- and control-infiltrated sectors.
|
|
| |
host ::
RSS.