The aim of the study was to develop an in situ PCR (IS-PCR) method for detection of bovine leukemia virus (BLV) in cell cultures. Samples from five BLV positive and five BLV negative cows were collected and dendritic cells (DCs) from blood, bone marrow, spleen, and lymph node were cultured. Cultures prepared from healthy animals were infected with BLV. After two weeks, the cells were tested by nested PCR and IS-PCR for the presence of proviral DNA. As a positive control adherent cell line permanently infected with BLV was used. BLV was successfully detected by IS-PCR in DCs from naturally infected cattle and DCs infected in vitro. In control, non-infected DCs, the results of the reaction were negative. The results of provirus detection by IS-PCR were similar with these performed with nested PCR. Additionally, IS-PCR provides many advantages, like specific localisation of infection and smaller number of cells needed as template for PCR.
Anna Orłowska, Ewelina Iwan, Marcin Smreczak and Jerzy Rola
High-throughput sequencing (HTS) identifies random viral fragments in environmental samples metagenomically. High reliability gains it broad application in virus evolution, host-virus interaction, and pathogenicity studies. Deep sequencing of field samples with content of host genetic material and bacteria often produces insufficient data for metagenomics and must be preceded by target enrichment. The main goal of the study was the evaluation of HTS for complete genome sequencing of field-case rabies viruses (RABVs).
Material and Methods
The material was 23 RABVs isolated mainly from red foxes and one European bat lyssavirus-1 isolate propagated in neuroblastoma cells. Three methods of RNA isolation were tested for the direct metagenomics and RABV-enriched approaches. Deep sequencing was performed with a MiSeq sequencer (Illumina) and reagent v3 kit. Bioinformatics data were evaluated by Kraken and Centrifuge software and de novo assembly was done with metaSPAdes.
Testing RNA extraction procedures revealed the deep sequencing scope superiority of the combined TRIzol/column method. This HTS methodology made it possible to obtain complete genomes of all the RABV isolates collected in the field. Significantly greater rates of RABV genome coverages (over 5,900) were obtained with RABV enrichment. Direct metagenomic studies sequenced the full length of 6 out of 16 RABV isolates with a medium coverage between 1 and 71.
Direct metagenomics gives the most realistic illustration of the field sample microbiome, but with low coverage. For deep characterisation of viruses, e.g. for spatial and temporal phylogeography during outbreaks, target enrichment is recommended as it covers sequences much more completely.
Agnieszka Korga, Ewelina Humeniuk, Grzegorz Adamczuk, Magdalena Iwan, Marta Ostrowska, Iwona Luszczewska-Sierakowska and Jarosław Dudka
Increasing numbers of oncological patients and growing drug resistance ensure that new methods of cancer treatment are intensively sought. Combining drugs for a synergistic effect is one of several possible ways to mitigate this problem. This leads to reducing the effective drug dose and the occurrence of side effects. Doxorubicin (DOX) is an antineoplastic agent that has several mechanisms of action. DOX intercalates between base pairs of DNA helix, inhibits topoisomerase II and also forms reactive oxygen species. Bortezomib (BZT) is an antitumor agent belonging to the group of proteasome inhibitors. It has been observed that BZT triggers an oxidative stress response in vitro and in vivo.
Accumulation of oxidatively damaged proteins and the simultaneously blocking of the proteasome can be very damaging to the tumour cell. For this reason, the aim of the study was to assess the potentially synergistic effect of DOX and BZT on human acute lymphoblastic leukemia (ALL). In the work, the cells were treated with both agents and their combinations and the effect was evaluated on the basis of morphological assessment, MTT assay and level of reduced glutathione measurement.
The study has shown that on acute lymphoblastic leukemia cells, synergistic effects came about in the combination of 1nM BZT with a wide range of concentrations of DOX. Herein, the visible, coactive effect of DOX and BZT was observed on oxidative stress levels. This phenomenon can be essential in blunting the possibility of rapid manifestation of resistance seen in BZT monotherapy. In addition, the needed very low concentrations of DOX reduce the risk of therapy side effect.
Agnieszka Korga, Milena Soroka, Karolina Wicha, Ewelina Humeniuk, Grzegorz Adamczuk, Magdalena Iwan, Marcin Sysa and Jaroslaw Dudka
One of the less known mechanisms of doxorubicin action is the effect on the functioning of the ubiquitin-proteasome degradation system (UPS). So far, the role of impaired proteasome activity in the development of anthracycline cardiomyopathy has not been clarified. It has been shown, however, that doxorubicin decreases the expression of proteins, including the expression of the calcium channel. However, it has not been established whether the observed disturbances are due to the activation of the UPS system by doxorubicin, or due to inhibition of translation or transcription. Therefore, the aim of the study was to evaluate the mRNA and protein expression of plasmalemmal (NaCaX, L-type) and sarcoplasmic reticulum (SERCA2, RyR2) channels in rat embryonic cardiomyocytes treated with doxorubicin and the proteasome inhibitor – bortezomib. The study was conducted utilizing the rat cardiomyocyte H9C2 line that was treated with doxorubicin and bortezomib in different concentrations. After 24 hours incubation, mRNA and protein expression analysis followed. The study did not show any universal mechanism of doxorubicin influence on calcium channel expression. With regard to the Na/Ca exchanger, we saw that DOX decreased the protein level in a proteasome activitydependent manner. Moreover, we noted that the SERCA2 protein expression level was regulated by degradation intensity, however at the same time, no significant effect of doxorubicin on the level of this protein was demonstrated.