@phdthesis{Guenzel2009, author = {Guenzel, Carolin Alexandra}, title = {The Characterization of Nipah Virus V and W proteins}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-37627}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2009}, abstract = {The work of the previous chapters describes the role of Nipah virus (NiV) V and W proteins regarding their role in interferon antagonism and regulation of viral replication. Previous publications have shown that NiV encodes IFN antagonist activity in its V, W and C protein (Park et al., 2003b; Rodriguez et al., 2002). In order to study the effect of both NiV proteins in the context of a virus infection, recombinant Newcastle disease viruses (rNDVs) expressing NiV V or NiV W were constructed. As a control virus served rNDV expressing NDV V proteins, which behaved like wildtype NDV. Growth kinetic experiments demonstrated that rNDVs expressing NiV V or W grew to higher titers than rNDV expressing NDV V in human A549 cells. This result suggested that both NiV V and W were able to render the avian virus, which normally does not replicate well in human cells, into a better growing virus. This hypothesis was supported by the fact that all rNDVs grew similarly in avian DF1 or Vero cells. When rNDV-infected A549 cells were specifically stained for NiV V or W protein it was observed that V is localized in the cytoplasm whereas W could be predominantly found in the nucleus. This observation was in agreement with previous studies reporting a nucleus export signal (NES) for NiV V and a nuclear localization signal (NLS) for NiV W (Rodriguez et al., 2004; Shaw et al., 2005). The specific localization of each NiV protein has also been shown to contribute to different functions in terms of IFN antagonism (Shaw et al., 2005). Here, NiV V and W proteins caused a severe attenuation of the immune response in rNDV-infected human A549 and dendritic cells. The transcription of type I interferons and ISGs was significantly downregulated in the presence of NiV V and W proteins. As a consequence of the transcriptional block, there was also an inhibition at the level of translation (as seen for A549 cells) and the secretion of IFNs and cytokines/chemokines (as seen for DCs). In contrast, NDV V protein induced a host immune response. Both NiV V and W also displayed a strong inhibitory effect on the function DCs. DCs represent a very important cell class because they link the innate immune response to the adaptive immune response (Banchereau \& Steinman, 1998). By downregulating the production and secretion of important cytokines/chemokines that are important for the activation of B and T lymphocytes, NiV V and W were able to disrupt that link. Interestingly, NiV W seemed to be a stronger inhibitor than NiV V in both A549 cells and DCs. Overall, it was demonstrated that NiV V and W were able to prevent the induction of the innate and adaptive host immune response cascade by inhibiting the transcription of immune genes in DCs and A549 cells. The second part of this work addressed the question whether NiV V and W proteins have a regulatory role in viral replication. This has been previously reported for Nipah virus itself (Sleeman et al., 2008) and other viruses (Atreya et al., 1998; Horikami et al., 1996; Witko et al., 2006). In order to study the ability of the V and W proteins of NiV to regulate viral transcription and/or replication, an existing NiV minireplicon assay was used (Halpin et al., 2004). Here, it was shown that NiV V and W (but not C) proteins significantly downregulated NiV minireplicon activity. The common N terminal region was shown to harbor the inhibitory activity. Co-immunoprecipitation experiments showed that both NiV V and W (but not C) were able to interact with NiV N, one component of the NiV polymerase. This result was supported by immunofluorescence experiments that revealed co-localization of NiV N with V and W. The binding of NiV V or W to NiV N occurred via their N terminus and more specifically amino acids 1-50. This suggested that V and W might inhibit viral replication by interacting with the viral polymerase resulting in a loss of function. Exact mechanisms still have to be elucidated.}, subject = {Viren}, language = {en} } @book{BockGauchGiernatetal.2013, author = {Bock, Stefanie and Gauch, Fabian and Giernat, Yannik and Hillebrand, Frank and Kozlova, Darja and Linck, Lisa and Moschall, Rebecca and Sauer, Markus and Schenk, Christian and Ulrich, Kristina and Bodem, Jochen}, title = {HIV-1 : Lehrbuch von Studenten f{\"u}r Studenten}, organization = {Bachelor- und Masterkurs Virologie 2013}, isbn = {978-3-923959-90-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78980}, publisher = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Dies ist ein Lehrbuch {\"u}ber die HIV-1 Replikation, Pathogenese und Therapie. Es richtet sich an Studenten der Biologie und der Medizin, die etwas mehr {\"u}ber HIV erfahren wollen und stellt neben virologischen Themen auch die zellul{\"a}ren Grundlagen dar. Es umfasst den Viruseintritt, die reverse Transkription, Genom-Integration, Transkriptionsregualtion, die Kotrolle des Spleißens, der Polyadenylierung und des RNA-Exportes. Die Darstellung wird abgerundet mit Kapiteln zum intrazellul{\"a}rem Transport, zu Nef und zum Virusassembly. In zwei weiteren Kapitel wird die HIV-1 Pathogenese und die Therapie besprochen. Zur Lernkontrolle sind den Kapiteln Fragen und auch Klausurfragen angef{\"u}gt.}, subject = {HIV}, language = {de} } @phdthesis{VuXuan2008, author = {Vu Xuan, Nghia}, title = {Generation of tools to investigate Chikungunya virus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-28993}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2008}, abstract = {CHIKV is the prototype of Alphaviruses and it causes an acute febrile illness with rash, severely painful arthralgias, and sometimes arthritis. While CHIKV has first been identified in the 1950s in Africa, recent outbreaks of CHIKV in the islands of the Indian Ocean and particular in Italia have re-drawn attention to CHIKV. In the past CHIKV disease was considered self-limiting and non-fatal. However, a number of deaths on Reunion (Anonym, 2006) during the outbreak, which was affected directly or indirectly by CHIKV, have changed this view. To defeat CHIKV outbreaks diagnostic tools and anti CHIKV therapies are urgently needed. In this thesis, we generated tools to investigate CHIKV at the molecular level by serological tests. CHIKV was isolated from a German woman who was infected during her holidays on the Mauritius Island. To characterize this viral isolate the complete viral genome was amplified by PCR and molecular cloned. In order to analyse antibody responses of infected individuals some of the structural and non-structural genes were subcloned in bacterial expression vectors. The NSP2, proteinase, capsid, E1 and E2 were subsequently expressed in E.coli using purified successfully. In this thesis, the structural proteins were used to develop a screening test for anti-CHIKV antibodies in patient derived serum samples. These tests were evaluated with pre-characterized anti-CHIKV sera (30 samples) obtained from the BNI Hamburg and 100 serum samples from German blood donors used as negative controls. Immunoblotting analysis revealed that up to 77\% of precharacterised positive sera could recognize the recombinant proteins and there were no detectable reactivity of CHIKV-negative German donor sera. The recombinant proteins were also recognized by 71.4\% of positive sera in the newly established ELISA. In order to go further in analyses of the results, an in house IFA was performed. Positive sera (21 samples) were used. The results showed that all of them reacted positive, but this assay was less sensitive than the IFA from BNI. In comparison with the IFA result from BNI Hamburg, the results were not congruent in all test performed. This could be due to various drawbacks of the tests. A cross reaction in Alphaviruses and the different strains are mentioned as well as the denatured forms of the structural proteins. Besides the main structural proteins (E1, E2 and C), other proteins such as non-structural proteins, uncleaved precursor proteins could participate in the different outcomes of serological assays. In order to go further in the CHIKV diagnoses, the CHIKV recombinant proteins were applied to screen the anti-CHIKV antibodies in the Vietnamese population, who are considered to live in the high risk regions. In serological tests, 158 sera of Vietnamese donors were incubated with the recombinant proteins or the fixed CHIKV infected cells. The results showed that 24\% of Vietnamese donor sera recognized the recombinant proteins in immunoblot assay, while 36\% scored positive in the ELISA assay. In IFA, the sera considered positive were 11.4\%. While some discrepancies in serological tests were found, these results showed that the ratio of CHIKV-positive sera seem to be equal to the other regions in the world, which are affected by CHIKV. It is suggested that CHIKV infection in Vietnam has been repeatedly misdiagnosed. This study cohort consisted only of samples originating from Hanoi area of Northern Vietnam, thus, future studies should expand to include samples from other Vietnam areas. To do this the various subtypes of the virus in the different regions should be isolated and the sequences of these viruses should be well characterized.}, subject = {Viren}, language = {en} } @phdthesis{Neske2009, author = {Neske, Florian}, title = {Entwicklung molekularbiologischer und serologischer Methoden zum Nachweis von Infektionen mit dem humanen Bocavirus und dem Polyomavirus WU}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-40424}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2009}, abstract = {Durch Viren ausgel{\"o}ste Infektionen der Atemwege z{\"a}hlen zu den h{\"a}ufigsten Erkrankungen des Menschen. Durch molekularbiologische Verfahren konnten in den vergangen Jahren bis dahin unbekannte Viren in respiratorischen Proben nachgewiesen werden, darunter das humane Bocavirus (hBoV) in 2005 und das Polyomavirus WU (WUPyV) in 2007. In der vorliegenden Arbeit wurden qualitative und quantitative DNA-Nachweisverfahren f{\"u}r hBoV und WUPyV etabliert und validiert, um retrospektiv die Infektionsh{\"a}ufigkeit von hBoV und WUPyV bei hospitalisierten Kindern mit akuter respiratorischer Erkrankung (ARE) der Universit{\"a}tskinderklinik W{\"u}rzburg zu untersuchen. Zus{\"a}tzlich wurden phylogenetische Untersuchungen dieser Viren durchgef{\"u}hrt. Zum Nachweis von Antik{\"o}rpern gegen Kapsidproteine von hBoV und WUPyV wurde ein auf rekombinanten Baculoviren basierender Immunfluoreszenztest (IFT) etabliert. HBoV-DNA konnte in 12 \% von 834 untersuchten Nasenrachensekreten (NRS) von Kindern mit ARE aus dem Zeitraum von Januar 02 - September 05 detektiert werden. Das mediane Alter der hBoV-positiven Kinder war 1,8 Jahre, die mediane hBoV-Last betrug 4,9 x 103 Kopien/ml. Bei einem großen Teil (39,1 \%) der hBoV-DNA-positiven Kinder wurden Koinfektionen mit anderen respiratorischen Viren detektiert, was jedoch keine signifikante Auswirkung auf die nachgewiesene hBoV DNA Menge hatte. Kinder mit Bronchitis wiesen eine signifikant h{\"o}here Viruslast auf als Kinder mit Fieberkr{\"a}mpfen. Im Rahmen einer Verlaufsstudie konnte hBoV-DNA bei einem Kind {\"u}ber einen Zeitraum von 4,5 Monaten in NRS nachgewiesen werden. Bei einem Teil der Kinder mit hBoV-DNA-positiven NRS wurden Serum- und Stuhlproben auf hBoV-DNA untersucht. In einer von 10 Serumproben und 14 von 31 Stuhlproben konnte BoV-DNA nachgewiesen werden. Dabei war die hBoV-DNA-Menge im NRS signifikant h{\"o}her, wenn die Stuhlprobe ebenfalls positiv war. Die phylogenetische Analyse von hBoV best{\"a}tigte die vom Erstbeschreiber ermittelten Cluster (St1 und St2). Diese Cluster weisen eine hohen Identit{\"a}t zueinander auf, sowohl auf Nukleotid- (\&\#8805;99,6 \%) als auch auf Aminos{\"a}ure (AS)-Ebene (\&\#8805;99,9 \%). Ein Zusammenhang zwischen den Clustern und klinischen oder virologischen Faktoren war nicht ersichtlich. Die Untersuchung auf IgG-Antik{\"o}rper gegen hBoV-VP2 ergab bei gesunden Erwachsenen eine Seropr{\"a}valenz von 74 \%. Ein Zusammenhang zwischen Alter und Seropositivit{\"a}t f{\"u}r hBoV-VP2 war nicht erkennbar. Die WUPyV-Untersuchungen wurden anhand von NRS durchgef{\"u}hrt, die im Zeitraum von Januar 02 - September 05 und Januar 07 - Juli 07 entnommen wurden. Dabei konnte WUPyV-DNA bei 5,2 \% der Proben mit einer medianen Viruslast von 9,5x 102 Kopien/ml nachgewiesen werden. Das mediane Alter der WUPyV-infizierten Kinder betrug 3,0 Jahre. Bei 54,8 \% der WUPyV positiven Kinder konnte eine Koinfektion mit einem anderen respiratorischen Virus festgestellt werden, wobei keine Korrelation zwischen Koinfektion und WUPyV-DNA-Menge ersichtlich wurde. Eine Assoziation zwischen der WUPyV-Last in NRS und klinischer Diagnose war nicht feststellbar. In 3 von 14 Serum- und 2 von 14 Stuhlproben von Kindern mit WUPyV-DNA-positivem NRS konnte WUPyV-DNA detektiert werden. Dabei war die WUPyV-Last im NRS von Kindern mit positivem Serum h{\"o}her als bei Kindern mit negativem Serum. Durch die phylogenetischen Untersuchung von WUPyV konnten zwei Cluster mit hoher Nukleotid-Identit{\"a}t (\&\#8805;99,2 \%) ermittelt werden. Der Großteil (60,3 \%) der Substitutionen war nicht synonym, was zu einer Identit{\"a}t auf AS-Ebene von 98,8 \% f{\"u}hrte. Von den AS Mutationen waren 76 \% Cluster-spezifisch. Mit dem etablierten WUPyV-spezifischen IFT konnte bei gesunden Erwachsenen eine IgG-Seropr{\"a}valenz von 88 \% f{\"u}r WUPyV ermittelt werden. Ein signifikanter Unterschied im medianen Alter zwischen Anti-WUPyV-VP1-positiven und -negativen Probanden konnte nicht festgestellt werden. Zusammenfassend konnte durch die etablierten molekularen und serologischen Nachweisverfahren die Infektionsh{\"a}ufigkeit von hBoV und WUPyV bei Kindern mit ARE, die Phylogenie der Viren und die Seropr{\"a}valenz bei gesunden Erwachsenen erforscht werden. Die in den vorliegenden Studien ermittelten Infektionsh{\"a}ufigkeiten f{\"u}r hBoV und WUPyV deckten sich mit anderen Publikationen zur Epidemiologie von hBoV und WUPyV. Durch die in dieser Arbeit durchgef{\"u}hrten Versuche konnten keine offensichtlichen Assoziationen zwischen einer hBoV- oder WUPyV-Infektion und einer respiratorischen Erkrankung festgestellt werden. Zur Untersuchung der Pathogenit{\"a}t von hBoV und WUPyV sind daher noch weitere Studien notwendig.}, subject = {Viren}, language = {de} }