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Attitudes and awareness of genetic testing for BRCA genes in women in Czechia
Nejedlová, Pavlína ; Kulhánová, Ivana (advisor) ; Hirsch, Ivan (referee)
The thesis deals with the issue of awareness and attitudes of women towards genetic testing for BRCA genes in Czechia. Genetic testing reveals hereditary predispositions of BRCA1 and BRCA2 gene mutations, which are associated with a high risk of hereditary cancers, especially breast and ovarian cancer. The thesis focuses on the importance of genetic testing, which can help to identify women at high risk of developing these diseases and to inform them sufficiently about appropriate preventive measures or recommendations for early treatment. Awareness and genetic counselling are important factors for individuals and their family members. Genetic mutations in the BRCA1 and BRCA2 genes are estimated to account for 5-10% of all breast and ovarian cancers. In this study, the association between social determinants and awareness of genetic testing is examined to determine whether these determinants are important in women's access to and awareness of testing. The analysis used data from 911 respondents who participated in the Sociological Survey of Citizens of the Czech Republic, a sample survey provided by the INRES agency. The binary logistic regression method was used to analyze the relationship between awareness of BRCA genetic testing and the attitude of women in Czechia towards undergoing such...
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Modulation of the STING signaling pathway
Vaneková, Lenka ; Veverka, Václav (advisor) ; Hirsch, Ivan (referee) ; Dobeš, Jan (referee)
cGAS-STING signalling pathway plays the key role in the host immune defence in diverse pathologies including, autoimmune and autoinflammatory diseases, cancer, senescence and ageing, pathogen infection, i.e., bacterial, viral infection, such as hepatitis B (HBV). HBV infection can result in either an acute or a chronic type (CHB), both of wide range of immune invading mechanism potentially leading to liver cirrhosis, steatosis, or hepatocellular carcinoma. Currently, two available CHB therapies are approved, both of which rarely result in the complete cure and often require life-long application. The development and validation of novel CHB therapeutics relies on suitable CHB animal models. The main goal of this thesis was to develop a mouse model reflecting CHB based on hydrodynamic injection suitable for robust preclinical testing of novel CHB therapeutics. Two delivery systems were compared, adeno-associated plasmid vector (pAAV) and minicircle construct, encoding HBV genomes of two genotypes (A or D) with introduced point mutation in the START codon of the polymerase in two immunocompetent mouse strains, C57Bl/6 and C3H/HeN. Persisting expression of viral antigens was observed only in the C3H/HeN mice when using pAAV construct encoding HBV genome of genotype A with introduced T2308C point...
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Host-virus interactions of mammalian endogenous retroviruses
Farkašová, Helena ; Elleder, Daniel (advisor) ; Hirsch, Ivan (referee) ; Mělková, Zora (referee)
Endogenous retroviruses (ERVs) originate by germline infection and subsequent mendelian inheritance of their exogenous counterparts. With notable exceptions, all mammalian ERVs are evolutionarily old and fixed in the population of its host species. Some groups of retroviruses were believed not to be able to form endogenous copies. We discovered an additional endogenous Lentivirus and a first endogenous Deltaretrovirus. Both of these groups were previously considered unable to form endogenous copies. Endogenous lentiviruses were discovered only recently and are still quite rare. These are still just small pieces of evidence insufficient to give a broader picture about the history of virus endogenization. We described a novel endogenous Lentivirus in the genome of Malayan colugo (Galeopterus variegatus) denoted ELVgv (endogenous Lentivirus of G. variegatus). Based on several analyses we proved that this is the oldest Lentivirus discovered up to date and confirmed its presence in the only other extant species of Dermoptera - Cynocephalus volans. Endogenous deltaretroviruses were the last group without a single endogenous member. We detected the remnants of endogenous Deltaretrovirus in the genome of Natal Long-fingered bat (Miniopterus natalensis). However, this sequence was present in the genome only in one...
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Study of endogenous retroviruses: Insight into the retroviral evolution and virus-host interactions
Hron, Tomáš ; Elleder, Daniel (advisor) ; Kejnovský, Eduard (referee) ; Hirsch, Ivan (referee)
In my doctoral project, I studied the evolution of retroviruses and long-term interactions with their hosts. Retroviruses infect a broad range of species including possibly all vertebrates. They are unique in their ability to efficiently create endogenous retroviruses (ERVs) - viral copies integrated into the host genomes and consequently inherited by successive generations as usual genomic locus. ERVs represent a significant portion of vertebrate genomes and play an important role in a variety of cellular processes and pathologies; however, their sequences are still largely unexplored. The results of my work contributed to the uncovering of ancient evolutionary history of retroviruses. In this regard, I employed the ERV sequences, as they represent "genetic fossils" of viral infections that occurred throughout entire retroviral evolution. By discovery and analysis of ancient ERV lineages, I shed light on the deep history of retroviruses and revealed how the past infections shaped the evolution of vertebrate antiviral defense. In addition to the investigation of retroviral evolution, I also studied process of ongoing endogenization and fixation of newly emerged ERVs in a mammalian host population. In this part of my work, I focused on a unique model of ERV that have been recently invading mule deer genome.
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Detection of human respiratory DNA viruses in the respiratory tract samples of immunocompromissed patients.
Blagoevová, Kateřina ; Hubáček, Petr (advisor) ; Hirsch, Ivan (referee)
Respiratory tract diseases are of the most common infectious diseases among both children and adult population all over the world. Viruses are the most frequent cause of respiratory diseases. In healthy immunocompetent individuals respiratory infection proceeds mostly without major complications. Immunocompromissed hosts, for example patients after transplatation, are more susceptible to infection and even common infection may be life threatening for them. Human polyomaviruses KI (KIPyV) and WU (WUPyV) and human bocavirus (HBoV) are most frequently detected in the respiratory tract of patients with acute respiratory tract infection primarily in children and in immunosuppressed patients. However, clear causative link between presence of these viruses and the respiratory disease has not been established. In this retrospective study were tested by quantitative real-time PCR 822 (745 from adults and 77 from children) respiratory samples from 380 immunocompromissed patients included 326 adults and 54 children. Viruses were also detected in the 84 peripheral blood samples. The most frequently detected virus was HBoV (6,32 % positive pacients), followed by KIPyV (5,79 % positive pacients) and WUPyV (0, 53 % positive patients). Only HBoV was detected in blood samples. The study confirmed the presence of KI...
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Gene expression in chicken embryo: micromanipulation and visualization methods
Bendová, Michaela ; Dvořák, Michal (advisor) ; Hirsch, Ivan (referee) ; Krylov, Vladimír (referee)
The aim of this work was to obtain better insight into the principles of cell structures and organs in the chicken embryo development. To reach this goal special methods of micromanipulations and visualization in vitro, ex vivo, ex ovo and in ovo were implemented and adjusted. These methods were used to study gene expression in neural crest development and eye development. In the course of long term research in our laboratory we observed that oncoprotein v-Myb influences the development of the neural crest and has the capacity to change natural cell fate. We performed a series of experiments to investigate v-Myb protein influence on neural crest cells differentiation, especially melanocyte lineage development, and its influence on gene expression in the neural crest. Therefore we focused on Gremlin 2 (PRDC), the gene upregulated by v-Myb in the neural crest. The established procedure of electroporation in ovo was adjusted to transfect cells of the developing eye and used to study gene expression during lens induction. The results obtained from chicken embryo experiments endorsed the study performed on mouse embryos. Futhermore, the electroporation technique was slightly modified for manipulations of the neural retina in the developing eye in ovo. Thereafter, the retinas were processed ex vivo and...
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Exosomes in viral infection and cancer
Sekavová, Alžběta ; Španielová, Hana (advisor) ; Hirsch, Ivan (referee)
Exosomes facilitate intercellular communication and transport of cellular cargo. Understanding the mechanisms underlying the cargo sorting to exosomes and the transport itself is crucial for vaccine development and diagnostic research. Exosome-mediated transfer contributes to immune response as well as progression of several diseases, including cancer and viral infections. Research on exosomes and their role in life cycles of tumorigenic viruses links already known mechanisms of viral carcinogenesis to the transport mechanisms of both cellular and viral proteins and nucleic acids. Epstein-Barr virus employs exosomes for transmission of the LMP1 oncoprotein and regulatory RNAs, whereas human immunodeficiency virus exploits cellular exosomal pathway for hijacking its membrane during budding, which helps it evade the immune system. It has been discovered that hepatitis C virus transfers its infectious virions between cells in exosomes. Exosomes containing oncoproteins and viral RNAs are also released from cells infected with other human tumorigenic viruses. However, mechanisms and implications of such events remain to be discovered. Keywords: exosome, cancer, viral infection, tumorigenic viruses, immunity, in- tercellular communication, hepatitis C virus, Epstein-Barr virus, human immuno- deficiency virus
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Effect of small DNA viruses on function of plasmacytoid dendritic cells
Janovec, Václav ; Hirsch, Ivan (advisor) ; Růžek, Daniel (referee) ; Filipp, Dominik (referee)
Plasmacytoid dendritic cells (pDC) are a highly specialized subset of immune cells that sense viral nucleic acids by endosomal toll-like receptors 7 and 9 (TLR7/9). Activation of TLR7/9 leads to the production of type I interferons (IFN-I). Moreover, pDC contribute to the antiviral response by presenting viral antigens to T lymphocytes and link innate and adaptive immunity. pDC need to be properly regulated in order to limit excessive production of IFN-I that is associated with autoimmune diseases. Therefore, pDC possess a battery of regulatory receptors (RR) that limit TLR7/9-mediated cytokine production. This thesis focuses on the mechanism of RR-mediated inhibition of IFN-I production in pDC and explores interactions between pDC and two enveloped viruses, that possess the ability to hijack RR in pDC: hepatitis B virus (HBV) and human immunodeficiency virus (HIV). We showed, that MEK-ERK signaling pathway plays an active role in RR-mediated inhibition of IFN-I in pDC. Our results indicate that in line with other studies of our group, pharmacological targeting of MEK1/2-ERK signaling could be a strategy to re-establish immunogenic activity of pDC. Then, we investigated whether antiretroviral therapy (ART) in a cohort of 21 treatment-naive chronic HIV-infected patients has restored the number and...
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Modulation of plasmacytoid dendritic cell function: role of immunoreceptors TIM-3 and BDCA-2
Font Haro, Albert ; Hirsch, Ivan (advisor) ; Němečková, Šárka (referee) ; Saláková, Martina (referee)
Albert Font Haro ABSTRACT Modulation of plasmacytoid dendritic cell function: role of immunoreceptors TIM-3 and BDCA-2 Plasmacytoid dendritic cells (pDCs) are key players in the antiviral response as well as in linking innate and adaptive immune response. They express endosomal toll-like receptors 7 and 9, which can detect ssRNA and unmethylated CpG DNA, respectively. Due to the constitutive expression of the transcription factor IRF7, pDCs are able to rapidly produce massive quantities of type I (α, β, ω) and type III (1, 2, 3, 4) interferons (IFN-I and IFN-III) as well as pro- inflammatory cytokines such as IL-1, IL-6 and TNF-α. After maturation, they also function as antigen-presenting cells. Despite intense research, the mechanisms of IFN and pro-inflammatory cytokines production and regulation are still poorly understood. Using the pDC cell line GEN2.2 and also primary human pDCs, we shed light on the role of kinases MEK and SYK in IFN-I production and regulation. We found that SYK is not only involved in the regulatory receptor (RR)-mediated BCR-like pathway that represents the negative regulation of IFN-I and IFN-III secretion but also in the positive TLR7/9-mediated signal transduction pathway that leads to IFN-I production, representing the immunogenic function. We also found that MEK plays a...
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