838 research outputs found
130 - Natascha Heise
No full textLearning and studying human anatomy is often associated with using rote knowledge. Novice students often memorize terms and structures in the laboratory with little reasoning skills. In attempt to promote application, integration, and critical thinking skills we introduced case based study into the human anatomy course at CSU. Early implementation suggested little change in student’s ability to solve novel problems using simple recall in attempt to answer case study questions. Here, we describe a novel approach using a 5-step method to promote critical thinking. Results suggest students application and integration during the case studies correlated with overall class performance
RNA-Seq analysis of chikungunya virus infection and identification of granzyme A as a major promoter of arthritic inflammation
No full textChikungunya virus (CHIKV) is an arthritogenic alphavirus causing epidemics of acute and chronic arthritic disease. Herein we describe a comprehensive RNA-Seq analysis of feet and lymph nodes at peak viraemia (day 2 post infection), acute arthritis (day 7) and chronic disease (day 30) in the CHIKV adult wild-type mouse model. Genes previously shown to be up-regulated in CHIKV patients were also up-regulated in the mouse model. CHIKV sequence information was also obtained with up to ≈8% of the reads mapping to the viral genome; however, no adaptive viral genome changes were apparent. Although day 2, 7 and 30 represent distinct stages of infection and disease, there was a pronounced overlap in up-regulated host genes and pathways. Type I interferon response genes (IRGs) represented up to ≈50% of up-regulated genes, even after loss of type I interferon induction on days 7 and 30. Bioinformatic analyses suggested a number of interferon response factors were primarily responsible for maintaining type I IRG induction. A group of genes prominent in the RNA-Seq analysis and hitherto unexplored in viral arthropathies were granzymes A, B and K. Granzyme Aand to a lesser extent granzyme K, but not granzyme B, mice showed a pronounced reduction in foot swelling and arthritis, with analysis of granzyme Amice showing no reductions in viral loads but reduced NK and T cell infiltrates post CHIKV infection. Treatment with Serpinb6b, a granzyme A inhibitor, also reduced arthritic inflammation in wild-type mice. In non-human primates circulating granzyme A levels were elevated after CHIKV infection, with the increase correlating with viral load. Elevated granzyme A levels were also seen in a small cohort of human CHIKV patients. Taken together these results suggest granzyme A is an important driver of arthritic inflammation and a potential target for therapy. Trial Registration: ClinicalTrials.gov NCT0028129
Equal Educational Opportunity, Hollow Victories, and the Demise of School Finance Equity Theory: An Empirical Perspective and Alternative Explanation
No full textProfessor Heise reports findings from his on-going empirical study of judicial impact in the school finance context. The study employs interrupted time series analyses to explore the independent effect of successful school finance equity court decisions on two key outcome variables, centralization and total educational spending levels. The results cast some doubt about long-held assumptions regarding the efficacy of court decisions. The author argues that the results also uncover important clues that help explain the recent fundamental shift in school finance litigation theory from equity to adequacy
Other endings of Mark as responses to Mark : an ideological-critical investigation into the longer and the shorter ending of Mark's Gospel
No full textThe Longer Ending and the Shorter Ending of Mark's Gospel are the ancient Markan readers' responses to Mark's Gospel. This leads us to the question of how the authors of these endings read their Mark's Gospel. These endings reflect the ideologies of their authors. The ideologies are related to the interests of the author or the authorial community (ideological primary group), and are embedded within the text. The Longer and the Shorter Ending were produced within a social context where the matter of apostolic authoritative leadership was a sensitive issue. A potential conflict is found in many contemporary texts from the NT and the extra- canonical texts, especially with regard to the apostolic authority of Mary Magdalene and Peter. Their struggles for apostolic authority are often found in the post-Easter narrative context. The assumed ideological primary community of the Longer Ending is Pro- Magdalene. It acknowledged Mary Magdalene as its authoritative leader who enjoyed apostolic authority especially over Peter. This community was interested in mission, and re-authenticated the mission of the Eleven. The LE provides a certain guideline for the qualification of leadership in the LE's community, which is the visual experience of the resurrected Jesus. The assumed ideological primary community of the Shorter Ending is Pro- Petrine. It was in favour of Peter, and suggested him as holding authoritative apostolic authority. This community wanted to clarify the resurrection of Jesus, and emended the empty tomb narrative of Mark's Gospel. It was also interested in mission, and the authority of disciples, especially that of Peter, in their performing mission tasks is highlighted in the Shorter Ending
HMGB1 amplifies ILC2-induced type-2 inflammation and airway smooth muscle\ua0remodelling
No full textType-2 immunity elicits tissue repair and homeostasis, however dysregulated type-2 responses cause aberrant tissue remodelling, as observed in asthma. Severe respiratory viral infections in infancy predispose to later asthma, however, the processes that mediate tissue damage-induced type-2 inflammation and the origins of airway remodelling remain ill-defined. Here, using a preclinical mouse model of viral bronchiolitis, we find that increased epithelial and mesenchymal high-mobility group box 1 (HMGB1) expression is associated with increased numbers of IL-13-producing type-2 innate lymphoid cell (ILC2s) and the expansion of the airway smooth muscle (ASM) layer. Anti-HMGB1 ablated lung ILC2 numbers and ASM growth in vivo, and inhibited ILC2-mediated ASM cell proliferation in a co-culture model. Furthermore, we identified that HMGB1/RAGE (receptor for advanced glycation endproducts) signalling mediates an ILC2-intrinsic IL-13 auto-amplification loop. In summary, therapeutic targeting of the HMGB1/RAGE signalling axis may act as a novel asthma preventative by dampening ILC2-mediated type-2 inflammation and associated ASM remodelling
Contributions of the Host Immune Response to Control and Protection upon Infection with a Neurovirulent Alphavirus
No full textAlphaviruses are mosquito-borne viruses within the family Togaviridae. These positive-sense RNA viruses pose a significant human and equine public health threat due to their ability to cause explosive epidemics of infectious rheumatic disease and encephalitis. The AR86 strain of Sindbis virus (SINV, infectious clone: S300) is neurovirulent in adult mice. A critical viral genetic determinant of neurovirulence within S300 is a Threonine at nonstructural protein (nsP) 1 position 538, whereby introduction of an Isoleucine at this locus is attenuating in vivo. The mutant nsP1 T538I virus induces more type I interferon (IFN) and fails to efficiently block type I and II IFN signaling as compared to S300 virus. Importantly, nsP1 T538I replicates as well as S300 virus at early times post-infection within the central nervous system (CNS) of infected mice, however at late times post-infection, nsP1 T538I is more efficiently controlled and cleared. In this work, we investigated the components of the host innate and adaptive immune system that modulate AR86-induced neurologic disease. Herein, we identify the IPS-1 pathway of intracellular RNA sensing as mediating protection from nsP1 T538I disease and driving viral clearance. Furthermore, we demonstrate that the TRIF-dependent pathway, which is essential for TLR3 and one pathway of TLR4 signaling, is moderately protective against the AR86 strain of SINV. IPS-1 and TRIF are adaptor molecules essential for signal transduction that results in the upregulation of interferon stimulated genes (ISGs), which in turn exert virus-specific antiviral activity. These studies reveal that two ISGs, IFIT1 and IFIT2, inhibit nsP1 T538I replication within IFN-&beta primed murine cells. We further demonstrate protective roles for T and B cells during nsP1 T538I infection, while the viral control conferred by T and B cells did not require their intrinsic ability to respond to type I IFN. Finally, these studies demonstrate contradictory phenotypes during AR86 infection of IFN-gamma receptor and cytokine knockout mice, thereby challenging the paradigm of IFN-gamma-mediated noncytolytic clearance from neurons. In sum, these studies identify key innate immune sensing pathways that modulate alphavirus neurovirulence and also refine our understanding of the role of adaptive immunity during clearance of a neurovirulent alphavirus.Doctor of Philosoph
Novel RNA Secondary Structures in Chikungunya Virus and Their Impact on Viral Replication
No full textChikungunya virus (CHIKV) is a single-stranded positive sense RNA mosquito borne alphavirus. In humans, this virus results in debilitating arthritis accompanied by fever, rash, myalgia, and headache. At this time, CHIKV has no licensed vaccines or approved specific treatments except for symptomatic relief such as NSAIDs to decrease inflammation. Thus far, the genome sequence of CHIKV and the proteins it encodes have been well studied, but the role the RNA secondary structure itself and the impact it has on viral replication and pathogenesis is less understood. Using SHAPE-MaP analysis, eighteen novel, highly stable RNA structures have been identified in the coding region of the CHIKV genome. To understand the function of these structures, we systematically disrupted each by introducing mutations that change their structure while maintaining codon usage and tested both the infectivity of the naked RNA through specific infectivity assays and viral replication through growth curves. At this time these structural mutants have not shown an impact on RNA infectivity or viral replication compared to that of a wild type vaccine strain of CHIKV (181/25) in mosquito or mammalian cells; however, further characterization in additional immune competent cell lines is required to fully understand the impact that these structures have on viral replication, pathogenesis, and host range. By defining the role that the novel RNA structures play in the lifecycle and pathogenesis of the CHIKV virus, it may expand the possible targets for CHIKV therapies and vaccines.Bachelor of Scienc
An Alphavirus nsP1 Determinant Modulates Type I Interferon Induction
No full textAlphaviruses are mosquito-transmitted viruses that can cause severe disease in both animals and humans. The host type I Interferon (IFN) response plays a critical role in limiting alphavirus infections. However, the specific interactions of type I IFN with that of the alphaviruses remain largely uncharacterized. Therefore, to gain insight into these early interactions, this study addresses the role of genetic virulence determinants in modulating the host type I IFN response. These analyses are based upon previous detailed mapping studies that identified a virulence determinant within the nsP1/nsP2 cleavage domain of the mouse adapted, neurovirulent Sindbis AR86 alphavirus that is critical for AR86 pathogenesis in vivo. We demonstrate that a Threonine to Isoleucine change at this position, leads to a mutant virus that robustly induces IFN independently of effects on viral replication or viral mediated shutoff of host macromolecular syntheses. Furthermore, we demonstrate that the modulation in type I IFN induction is not specific to the Sindbis AR86 virus, as a similar mutation within the Ross River Virus, also leads to robust type I IFN responses, suggesting that the nsP1/nsP2 determinant may be fundamentally important for all alphaviruses. Additional work has established that the nsP1/nsP2 determinant modulates type I IFN induction through the IPS-1 signaling pathway, primarily mediated by the RIG-I and PKR receptors. As RIG-I and PKR recognize specific RNA ligands, such as free 5' triphosphates on uncapped viral RNAs, we next determined whether the nsP1/nsP2 determinant would disrupt the viral capping apparatus. We found increased synthesis of uncapped viral 26S subgenomic RNAs made within infected cells containing the nsP1/nsP2 mutation. Furthermore, the uncapped 26S RNAs differentially activated RIG-I which was phosphatase dependent. Therefore, altogether, our data presents a novel mechanism in which a genetic determinant specifically enhances the viral capping apparatus in order to evade the host type I IFN receptors. And disruption of the capping apparatus leads to the synthesis of uncapped RNAs that are efficiently recognized by the RIG-I and PKR host sensors to induce IFN to aid in the clearance of the viral infection
Alphavirus Evasion of Type I Interferons
No full textAlphaviruses are mosquito transmitted viruses that cause either severe arthritis or encephalitis. A critical stage that determines whether or not alphavirus infection will result in disease is the early interaction of the virus with the host following delivery from the mosquito vector. Of particular importance are interactions between mosquito derived virions and myeloid dendritic cells (mDC's) within the skin and draining lymph node. Therefore a focus of these studies was to evaluate if alphaviruses derived from either mosquito or mammalian cells interacted differently with mDC's. Our results revealed mosquito-cell-derived Ross River virus and Venezuelan Equine Encephalitis virus (mos-RRV and mos-VEE) more efficiently infected mDC's when compared to the same viruses grown in mammalian cells (mam-RRV and mam-VEE). However, mos-RRV and mos-VEE infection poorly induced type I interferons (IFN-αβ) when compared to mam-RRV and mam-VEE, suggesting that mosquito-cell-derived alphaviruses could either avoid or inhibit antiviral responses from infected mDC's. A major difference between mammalian and mosquito grown viruses is that mosquito-cell-derived virus particles exclusively incorporate terminal mannose N-linked glycans onto their glycoproteins, while mammalian-cell-derived viral glycoproteins incorporate complex, hybrid, and terminal mannose oligosaccharides. Differential IFN-αβ induction was linked to glycosylation since mDC's infected with viruses grown in mammalian cells that produce virions with only mannose glycans induced less IFN-αβ than mDC's infected with viruses grown in mammalian cells with complex glycans. Additional studies suggested that mos-RRV did not actively suppress mDC IFN-αβ production, since co-infection of mos-RRV with mam-RRV did not inhibit IFN-αβ responses. We next generated a panel of RRV glycan deficient viruses to identify the role for each N-linked glycan in IFN-αβ production. The panel revealed that E2 glycans on mam-RRV, but not mos-RRV, were required for robust IFN-αβ responses following mDC infection. These data suggest that poor IFN-αβ responses from mDC's following mos-RRV infection is attributed to a lack of complex glycans on the virion envelope. In summary, these data provide new insight into how mosquito-borne viruses evade IFN-αβ responses which may aid in their ability to establish infection
Characterization of N-Linked Glycans of Chikungunya Virus
No full textChikungunya virus is an arthropod-borne alphavirus that, in recent years, has presented an
increased threat to human populations as the Aedes aegypti mosquitos which carry it have
experienced resurgence in their population and by genetic adaptation to a new vector: aedes
albopictus. Chikungunya virus contains three glycoproteins (E1, E2, E3). E2 contains two Nlinked
glycosylation sites (N263, N345), and E1 contains a single site (N141). These glycans
may be important for modulating host interferon response and tropism, as has been shown for
other alphaviruses. This thesis seeks to identify the primary oligosaccharide at each
glycosylation site by endoglycosidase digestion and SDS-PAGE. Furthermore, the experiments
described herein aim to determine the effect of the removal of either or both of the N-linked
glycans of E2 on its ability to bind Human Prohibitin-1, a previously identified receptor.Bachelor of Scienc
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