National Repository of Grey Literature 51 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Characterization of viral nanoparticles derived from mouse papillomavirus
Vomáčka, Petr ; Španielová, Hana (advisor) ; Šmahelová, Jana (referee)
The L1 and L2 capsid proteins of papillomaviruses are characterized by the ability to self- assemble into viral capsids, which can be divided into pseudovirions (PsVs) and virus-like particles (VLPs) by inner content. In addition to the fact that such particles can serve as "nano-containers" for diagnostic and therapeutic agents, it has also been shown that papillomaviruses, whether wild, PsVs or VLPs have a higher affinity for tumor tissue than non-tumor tissue. This thesis deals with relatively newly discovered (2011) mouse papillomavirus (MusPV) and nanoparticles derived from this virus. This papillomavirus has been chosen for its positives, including easy preparation of VLPs and PsVs, as well as an available model organism for possible testing. Furthermore, MusPV has the potential for use in gene therapy and cancer diagnosis, because there is no immune response in the human population. The aim of this diploma thesis is to prepare an expression system for the production of PsVs and VLPs. In additional it will also look at the quality and quantity of PsVs and VLPs, characterization of these particles and verification of existing postulates regarding higher affinity of papillomaviruses for tumor cells. Finally, it will also to verify whether the same effect is observed in MusPV. In the results of...
Analysis of antibody response during BK virus infection
Tomanová, Tereza ; Španielová, Hana (advisor) ; Saláková, Martina (referee)
BK virus is a human polyomavirus which is highly prevalent in the population. The virus is usually not very dangerous to its host, but it may cause complicati- ons in immunosuppressed patients. These complications commonly appear after kidney transplantation because BK virus persists in kidney epithelial cells. There are four subtypes of BK virus and it might be clinically important to screen for the identity of subtypes in matched pairs of donors and recipients of the kidney. This determination of the subtype specific antibodies by simple test could help to manage complications after the surgery. During previous project the ELISA test that could serologically differentiate between two main BK virus subtypes (I and IV) was designed, but its development is complicated by the fact that there is a strong cross-reactivity between the BK virus subtypes and antibodies. The modification of antigen towards better specificity might be required to succeed. Consequently, the main aim of this diploma thesis was to map important spots of major capsid protein VP1 of BK virus, particulary in EF and DE loops, which could participate in binding of antibodies. This aim was addressed by targeted mutagenesis of the gene coding VP1 protein in the region of the respective loop. Nucleotides coding two surface aminoacids...
Pseudotyping in baculoviruses
Zobalová, Eliška ; Španielová, Hana (advisor) ; Fraiberk, Martin (referee)
The baculoviruses are a group of enveloped DNA viruses that infect the larval stage of arthropods, mainly insects. They are widely used in biotechnology and well known for their utility as biological pesticides and gene expression vectors for the production of proteins in insect cells and larvae. However, they are also able to enter in mammalian cells and deliver-genes for expression under the control of mammalian cell-active promoters. Recombination or pseudotyping can result in formation of baculoviruses that provide a higher transduction frequency or are able to recognize specific mammalian cells. This bachelor thesis describes the phenomenon of viral pseudotyping and summarizes published information about the use of pseudotyped baculoviruses for gene therapy and vaccination.
Identification of genes responsible for tumor induction with avian retroviruses subgroup J
Gašpareková, Mária ; Pečenka, Vladimír (advisor) ; Španielová, Hana (referee)
Retroviruses are viruses which are able to integrate to genome of host cell. Nonrandom integration of provirus near or inside some cellular genes may result in their deregulation, activation or silencing. This can later lead to cell transformation and tumor formation. This thesis discusses identification of viral integration sites (VIS) and common integration sites (CIS) in tumors originating from different organs (mostly kidneys, lungs and liver) with using mostly avian retroviruses subgroup J, specifically first natural isolate HPRS-103 and laboratory made virus MAV-J, which was made by replacing gene envB by envJ. Infection was made in ovo using chicken breeds Brown Leghorn and White Leghorn and tumors were isolated from 8 to 28 weeks after infection. For molecular analyses was used inverse PCR method and sequencing. From 74 molecularly analyzed tumors there was detected 373 VIS and 6 CIS with statistical significance over 2.10-2 . Gene with the highest number of hits was FRK (14 times), then TERT (5 times), CTDSPL (5 times), EGFR/ERBB1 (3 times), MYB (3 times) and MYC (3 times). Except 6 CIS there were other genes found, which had smaller statistical significance. Keywords: retrovirus, insertional mutagenesis, subgroup J, oncogenesis, oncogenes, MAV-J, HPRS-103, proviral integration sites, tumors
Targeting of viral nanoparticles to cancer specific receptors
Žáčková Suchanová, Jiřina ; Španielová, Hana (advisor) ; Němečková, Šárka (referee) ; Ulbrich, Pavel (referee)
The aim of this thesis is to reveal the potential of mouse polyomavirus (MPyV) based virus-like particles (VLPs) as possible nanocarriers for directed delivery of therapeutic or diagnostic compounds to specific cells or tissues. We have chosen mouse polyomavirus VLPs because they do not contain viral DNA and are considered safe for utilization in bio-applications. In our research, we used a chemical approach for retargeting of MPyV based VLPs from their natural receptor to cancer cells. The chemical modification of the capsid surface exposed lysines by an aldehyde-containing reagent enabled conjugation of VLPs to selected molecules: transferrin and inhibitor of glutamate carboxypeptidase II (GCPII). Transferrin, as a transporter of iron to metabolically active cells, targeted VLPs to numerous types of cancer cells overexpressing the transferrin receptor. On the other hand, GCPII serves as a transmembrane marker specific for prostate cancer cells and conjugation of its inhibitor to VLPs resulted in successful recognition of these cells. Electron microscopy was used for visualization of modified VLPs and flow cytometry together with confocal microscopy for investigation of cell specific interactions and VLP uptake. Furthermore, we explored the influence of serum proteins on VLPs. The abundance of...
The importance and role of reverse transcriptases in gene expression analysis
Žucha, Daniel ; Valihrach, Lukáš (advisor) ; Španielová, Hana (referee)
The continuously advancing field of gene expression analysis enables the evaluation of even the slightest changes that occur in the cell transcriptome. In order to ensure accuracy of the observed biological variances, it is fundamentally important to be aware of the possible biases introduced during sample processing. In gene expression research, the methods of reverse transcription−quantitative PCR (RT−qPCR) and RNA- Sequencing (RNA-Seq) are often the primary choice, mostly because of their high precision and reproducibility. Since these both methods require DNA template, they are coupled with the same initial step - reverse transcription (RT), a reaction producing DNA complementary to its RNA template. It is well known that RT introduces bias. As a result, it is therefore of importance to thoroughly evaluate the effects of these biases. One such annotated source of artifacts is the reverse transcriptase (RTase) itself. However, it has been shown that the enzyme does not account for most of the variance alone. Surprisingly, choice of primers or RNA template may influence the reaction outcome even more than the bias introduced from the enzyme. This is especially the case with recent advances in protein engineering. Production of highly efficient RTases may pronounce the variation originating from...
The role of JC virus in etiology and therapy of multiple sclerosis.
Musil, Dominik ; Španielová, Hana (advisor) ; Šmahelová, Jana (referee)
JCPyV is a human polyomavirus. Infections caused by this type of virus is often without any clinical symptoms and JCPyV mostly persists in kidneys of human for the rest of the life. The most serious disease caused by the JCPyV is progressive multifocal leukoencephalopathy, which causes severe demyelination of neurons in the brain. Multiple sclerosis, as well as progressive multifocal leukoencephalopathy, is characterised by the demyelinization of neurons. In the past few years, it was shown that the development of PML occurs in some pacients who suffered from multiple sclerosis and who were treated with the monoclonal antibody called natalizumab (Tysabri). This text describes the analysis of the conncetion between viral infection of JCPyV and the etiology of multiple sclerosis and progressive multifocal leukoencephalopathy. As the risk factors for the progression of progressive multifocal leukoencephalopathy in natalizumab treated multiple sclerosis patients the duration of the use, previous immunosuppressant therapy and the presence of the anti-JCPyV antibodies have been demonstrated. In addition to these risk factors, it has also been demonstrated that the people with progressive multifocal leukoencephalopathy have mutations in the genome of virus in the regulatory region, as well as in the...
Raccoon polyomavirus: example or exception of polyomavirus driven oncogenesis?
Schreiberová, Lucie ; Španielová, Hana (advisor) ; Hirsch, Ivan (referee)
Polyomaviruses (PyV) are widespread through human and animal populations and typically associated with asymptomatic persistent infection. Rarely, natural PyV infections can lead to oncogenic transformation. Virus genome is usually integrated into the host DNA of tumour tissue. Over the past few years, an increased number of very aggressive brain tumours and olfactory tumours have been observed in raccoons. These tumours are associated with the newly discovered raccoon polyomavirus, which was found as an intact episome in host cells. This bachelor thesis is therefore focused on comparison of current state of knowledge on raccoon polyomavirus with previously described mechanisms of PyV tumorogenesis. Unlike for other PyVs, the fact that primary neuronal stem cell infection is most likely to occur can play a key role in raccoon polyomavirus driven oncogenesis. Tumours also exhibit unusually high expression of virus-encoded micro RNA that can be connected with tumour induction. Similary to other tumours caused by PyV, a large amount of early viral proteins with oncogenic potential is found in tumours. Revealing unknown factors responsible for the development of tumours caused by raccoon polyomavirus may help in understanding of mechanisms of oncogenesis. Key words Polyomavirus, oncogenesis, raccoon...
Influence of size and geometry of nanoparticles on cellular internalization pathways
Číhařová, Barbora ; Španielová, Hana (advisor) ; Lišková, Petra (referee)
Nanoparticles can be used in biomedical disciplines as carriers for transport of diagnostic as well as therapeutic substances into cells. Variety of different shapes, sizes and different compositions are used experimentally. Despite the discoveries already made in this area, the exact nature of the interaction between a nanoparticle and a cell has not been fully understood yet. The objective of this thesis is to provide the knowledge about possibilities of utilisation and aspects influencing the interaction between the cell membrane and several types of nanoparticles: liposomes, gold nanoparticles and virus-like nanoparticles. The comparison shows that generalisation of the mechanism of nanoparticle entry into the cell is problematic, although it seems that the spherical nanoparticles with the diameter of 50 nm provide the most efficient entry.

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