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Foster, Rosalinda Gram. "Virus-Host Interactions in the Development of Avian Leukosis Virus-Induced Osteopetrosis: a Dissertation." eScholarship@UMMS, 1993. https://escholarship.umassmed.edu/gsbs_diss/180.
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Avian leukosis virus (ALV)-induced osteopetrosis is a proliferative disorder of the bone affecting the growth and differentiation of osteoblasts. Osteopetrosis is a polyclonal disease in which cells of the bone contain, on average, multiple viral DNA copies. Osteopetrotic bone is also characterized by the accumulation of unintegrated viral DNA, suggesting an atypical life cycle of the virus in the infected osteoblasts. To better understand virus-host interactions in the induction of osteopetrosis by ALVs, infected chick osteoblast cultures and osteopetrotic bone were examined for aspects of the virus life cycle and effects of infection on osteoblast function.
Levels of infection and virus expression were compared in cultured osteoblasts and osteopetrotic bone. Osteopetrotic bone contained higher levels of viral DNA and correspondingly higher levels of viral proteins than infected osteoblast cultures, suggesting a higher viral load in the diseased bone. A significant level of mature Gag protein was present in the bone, suggesting the accumulation of mature virus particles in the diseased bone. It is possible that the accumulation of virus could facilitate the high levels of infection observed in the diseased bone.
The mechanism by which unintegrated viral DNA persisted in osteopetrotic bone was investigated by examining the susceptibility of infected osteoblasts to superinfection. The results indicated that, in culture, infected osteoblasts were able to establish interference to superinfection. This suggests that the persistence of unintegrated viral DNA in osteopetrotic bone may not result from the continuing infection of productively infected osteoblasts.
The effect of virus infection on osteoblast function was examined in the diseased bone and in osteoblast cultures. In infected chickens, osteoblast activity, as evidenced by the expression of osteoblast phenotypic markers, was increased only in chickens developing severe osteopetrosis. In culture, virus infection had no apparent effect on either the proliferation or differentiation of osteoblasts. This indicates that infection was itself not sufficient to perturb osteoblast function. Furthermore, it suggested that additional components of the bone may be required for ALV infection to induce the abnormal activity of osteoblasts observed in osteopetrosis.
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Gould, Keith Geoffrey. "Cytotoxic T cell recognition of the influenza A/PR/8/34 haemagglutinin." Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293397.
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Masiri, Jongkit Murphy John F. "The nature of cucumber mosaic virus-induced symptoms in bell pepper (Capsicum annuum L.)." Auburn, Ala., 2009. http://hdl.handle.net/10415/1977.
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Zaver, Himesh, Momani Laith Al, Kalpit Devani, and Chakradhar M. Reddy. "Ledipasvir/sofosbuvir induced nephrotic syndrome: A challenging case of Hepatitis C management." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/asrf/2018/schedule/80.
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ABSTRACT:
Hepatitis C virus (HCV) is associated with various glomerulopathies and nephrotic syndrome. However nephrotic syndrome following treatment is rare. Ledipasvir/sofosbuvir (L/S) has recently come into favor in treating HCV due to its relatively mild side effects compared to the more traditional interferon therapy. To the best of our knowledge, there are no reported cases of nephrotic syndrome following treatment with L/S. We present a case of nephrotic syndrome suspected secondary to L/S in a patient with chronic kidney disease. Increased vigilance when assessing therapeutic options in HCV patients with renal comorbidities can improve patient outcomes. A 63 year-old male patient presented to the hospital with shortness of breath, and a two-week history of bilateral lower extremity edema. Past medical history was significant for liver cirrhosis secondary to Hepatitis C genotype Ia, hepatocellular carcinoma status post liver transplantation 6 months prior to admission and Stage 3b chronic kidney disease with baseline creatinine (Cr) approximately 1.5 mg/dl. Medications included L/S for HCV and tacrolimus and prednisone for post-transplant treatment. Patient’s vitals were stable and physical exam was remarkable for facial swelling, mainly on the eyelids, decreased breath sounds bilaterally, distended abdomen with a fluid wave, and 2-3+ pitting edema up to the knees on lower extremities bilaterally. Laboratory work-up was remarkable for low albumin of 3.0 g/dl, and total protein of 5.6 g/ dl. Creatinine of 1.8 mg/dl was elevated from patient’s baseline. HCV viral load was undetectable and electrolytes, transaminases and the complete blood count were within normal limits. Subsequently, urine protein to creatinine ratio was measured because of generalized swelling and hypoproteinemia, which was found to be significantly high at 8.80, compared to 0.04 one year prior. 24-hour total urine protein was found to be 2065 mg/day. Renal ultrasonography showed no hydronephrosis and was otherwise unremarkable. Renal biopsy however, revealed changes suggestive of membranoproliferative glomerulonephritis (MPGN] most likely secondary to HCV. No immune complexes, lambda/kappa light chains, or cryogloblin were appreciated. Nephrotoxic agents such as diuretics and corticosteroids were held. Tacrolimus trough was appropriate to dose level and was continued along with L/S. As admission progressed the patient’s creatinine continued to get worse and rose up to 4.3 mg/dl with persistent proteinuria. With tacrolimus trough levels within normal limits and given L/S was the most recently initiated drug, L/S was thought to be the culprit and was thus held. The renal function began to improve gradually, and the patient was discharged in stable condition with close follow up. Follow up one month later found creatinine and renal function return to baseline and proteinuria resolved. Our case shows that Ledipasvir/sofosbuvir may possibly be related to nephrotic syndrome in HCV patients. Although further studies are needed to prove the causality our case seeks to raise clinical suspicion and increase vigilance when assessing therapeutic options in HCV patients with renal comorbidities such as chronic kidney disease.
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Wong, Tsz-yeung, and 王子揚. "Molecular characterization of IBDV-induced apoptosis in vitro using cDNA microarrays." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B36375998.
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Torok, Valeria Anna. "Biological and molecular variation among isolates of pea seed borne mosaic virus." Title page, contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09pht686.pdf.
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Corrigendum inserted at the back. Includes bibliographical references (leaves 133-158). Ch. 1. General introduction -- ch. 2. General materials and methods -- ch. 3. Biological characterisation of Australian PSbMV isolates -- ch. 4. Developing nucleic acid based diagnostics for PSbMV -- ch. 5. Detection of PSbMV isolates by RT-PCR and RFLP analysis -- ch. 6. Developing an internal control for PSbMV RT-PCR -- ch. 7. Molecular analysis of the PSbMV VPG -- ch. 8. PSbMV sequence and phylogenetic analysis -- ch. 9. General discussion Sixteen pea seed borne mosaic virus (PSbMV) isolates were collected between 1995 and 1998. These isolates were biologically distinct yet serologically indistinguishable. The conclusion is that PSbMV is widespread and occurs at a low incidence in Australia. Reports sequence information on new isolates of PSbMV which has allowed genomic regions to be identified which distinguish PSbMV pathotypes and isolates; and, to the development of PSbMV nucleic acid hybridisation and RT-PCR assays.
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Magalo, Simone Issaca. "Evaluation of immunity and protection induced in pullets by the V4 oral vaccine against a pneumotropic velogenic Newcastle disease virus (NDV) strain." Diss., University of Pretoria, 2002. http://upetd.up.ac.za/thesis/available/etd-11042005-140706/.
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Yuen, Kit-man, and 阮潔雯. "Comparison of influenza A virus induced apoptosis in human respiratoryepithelial cells: an in vitro and ex vivostudy." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47177019.
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Highly pathogenic avian influenza H5N1, which is panzootic in poultry, continues to spread and becomes endemic in Asia, Africa, and Europe. It causes human disease with high fatality (about 60%) and continues to pose a pandemic threat. The pathological lesions associated with human H5N1 disease is Acute Respiratory Distress Syndrome (ARDS). The biological basis underlying the development of ARDS in human H5N1 disease remains controversial. Clinical, animal and in vitro studies suggested that the differences between H5N1 influenza viruss and low pathogenic influenza viruses in regard to viral replication, tissue tropism and cytokine dysregulation may contribute to disease pathogenesis.
We previously found delayed onset of apoptosis in influenza H5N1 virus infected human peripheral blood monocyte-derived macrophages. This may allow a longer survival time for the virus in target cells for prolonged viral replication, which may contribute to the pathogenesis of H5N1 disease. As human bronchial and alveolar epithelial cells are target cells of influenza virus, I explored if influenza H5N1 and H1N1 virus infected human respiratory epithelial cells displayed differential apoptotic response and dissected the apoptotic pathways triggered by influenza virus infection.
In this study, the apoptotic response in highly pathogenic influenza H5N1 viruses, A/HK/483/97 and A/Vietnam/1203/04, their precursor avian influenza H9N2 virus, A/Quail/HK/G1/97, and seasonal H1N1 virus, A/HK/54/98 infected primary human alveolar and bronchial epithelial cells was compared by TUNEL. A delayed onset of apoptosis in influenza H5N1 viruses and avian H9N2 virus infected alveolar epithelial cells was observed; the pattern was similar in bronchial epithelial cells. Concomitantly, by Western blotting, a delay in caspase 3 activation in H5N1 virus (A/HK/483/97) infected alveolar epithelial cells compared to H1N1 virus (A/HK/54/98) infected cells was shown. Also, influenza H5N1 and H1N1 virus induced apoptosis through both intrinsic and extrinsic pathways in human alveolar epithelial cells. Chemokine IP-10 was differentially up-regulated in influenza H5N1 virus infected alveolar epithelial cells, but its relationship to the delayed onset of apoptosis requires further studies.
TRAIL, an upstream signaling molecule of extrinsic apoptotic pathway, mRNA was up-regulated in influenza H5N1 infected alveolar epithelial cells but not in influenza H1N1 infected cells. Using recombinant viruses, I showed that the 627 amino acid residue on PB2 of H5N1 virus and mutation of amino acids on 253 and 591 residues on PB2 of H9N2 virus contribute to the TRAIL upregulation. Immunohistochemical staining of physiologically relevant ex vivo model of human bronchus showed that influenza H5N1 (A/Vietnam/3046/04) and H9N2 (A/Quail/HK/G1/97) virus did not infect human bronchi as well as human H1N1 (A/HK/54/98) virus. Profiling of apoptosis related genes showed that TRAIL tends to be up-regulated in H5N1 virus infected bronchi ex vivo.
This study demonstrated the delayed onset of apoptosis by H5N1 virus infected respiratory epithelial cells may be a mean for influenza virus to have prolonged replication within the human respiratory tract and contribute to disease severity. The results generated provide a robust research agenda, yielding critical information that elucidate molecular mechanisms, such as TRAIL up-regulation, that may contribute to the virulence and pathogenesis in human H5N1 disease.HKU 3 Minute Thesis Award, 2rd Runner-up (2011)
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Master of Philosophy
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Hansmann, Florian Heinrich [Verfasser]. "The pathogenic role of matrix metalloproteinases in a virus-induced mouse model of demyelinating diseases / Florian Heinrich Hansmann." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2012. http://d-nb.info/1024435393/34.
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Poulin, Louise. "Expression differentielle du produit du gene 'src' dans les tumeurs induites par le virus de sarcome aviaire = Differential expression of the 'src' gene product in tumor cells induced by avian sarcoma virus." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74020.
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Hinton, Michael. "Cellular Mechanisms by which Alcohol Promotes HIV Protease Inhibitor-induced Hepatotoxicity." VCU Scholars Compass, 2019. https://scholarscompass.vcu.edu/etd/6089.
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CELLULAR MECHANISMS BY WHICH ALCOHOL PROMOTES HIV PROTEASE INHIBITOR-INDUCED HEPATOTOXICITY
Michael Hinton, B.S.
A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University Virginia Commonwealth University, 2019
Major Director: Huiping Zhou
Professor, Department of Microbiology and Immunology
The development of highly-active-antiretroviral therapy(HAART) has allowed management of HIV and extended the lives of those infected. Alcohol abuse, which is very common in HIV-1 infected patients, is one of the most important co-morbid risk factors for liver injury and has been associated with the occurrence of serious metabolic syndrome and subsequent discontinuation of HAART in HIV patients. We have identified endoplasmic reticulum (ER) stress-induced proapoptotic factor CCAAT-element-binding protein homologous protein (CHOP) as an important mechanism underlying HIV PI-induced inflammation and hepatic lipotoxicity. However, little is known about the mechanistic pathways by which alcohol promotes HIV PI-induced hepatic lipotoxicity. The aim of this study was to determine if inhibition of CHOP expression prevents alcohol- and HIV PI-induced apoptosis and dysregulation of lipid metabolism. We demonstrated that co-administration of alcohol and HIV PIs induced unfolded protein response (UPR) activation, ER stress, and CHOP upregulation in rodent hepatocytes. Both alcohol and HIV PI-induced lipid accumulation and apoptosis were significantly reduced in CHOP-/- hepatocytes. Also, CHOP-/- hepatocytes treated with alcohol and HIV PIs showed inflammation.. Activation of the ER stress-induced proapoptotic factor CHOP is a key cellular mechanism underlying alcohol and HIV PI-induced hepatotoxicity. CHOP expression is key for alcohol and HIV PI-induced dysregulation of key genes involved in lipid metabolism in hepatocytes. Limitations of the study include the usage of global CHOP-/- in lieu of tissue-specific conditional knockout mouse models, nonobservance of the effects of alcohol and HIV PIs on extra-hepatic tissues, and incomplete investigation of the interplay of hepatocytes and resident macrophages.
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Jackson, Marion Louise. "Molecular detection and analysis of feline leukemia virus (FeLV) long terminal repeat (LTR) sequences in neoplastic and non-neoplastic FeLV-induced diseases of domestic cats." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq24060.pdf.
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Sun, Jingru. "Nectin-1 is Degraded in Chlamydia trachomatis-Infected Genital Epithelial Cells and is Required for Herpes Simplex Virus Co-Infection-Induced C. trachomatis Persistence." Digital Commons @ East Tennessee State University, 2009. https://dc.etsu.edu/etd/1795.
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The obligate intracellular bacterium Chlamydia trachomatis is the most common bacterial STD agent in the US. This bacterium has a unique biphasic developmental cycle in which the infectious elementary body (EB) infects a host mucosal epithelial cell and differentiates into the replicative form (the reticulate body or RB) within a modified vacuole called an inclusion. The RB later divides and develops back into an EB and is released, perpetuating the infectious cycle. When developing chlamydiae are exposed to unfavorable environmental conditions, they deviate from the normal developmental cycle into a non-infectious but viable state termed persistence. Previous data from our laboratory indicate that i) during C. trachomatis/HSV co-infection, the chlamydiae become persistent and ii) HSV gD interaction with host cell surface is sufficient to induce this response. During viral entry, HSV gD interacts with one of four host co-receptors, one of which is the host adhesion molecule nectin-1. Interestingly, Western blotting demonstrated that nectin-1 is significantly decreased in C. trachomatis-infected HeLa cells. Additional studies indicated that active C. trachomatis replication is required for nectin-1 down-regulation and nectin-1 is likely down-regulated post-translationally. CPAF, a chlamydia-secreted protease, is responsible for degrading several host proteins. Both in vivo experiments using CPAF-specific chemical inhibitors and cell-free cleavage assays using recombinant CPAF indicate that nectin-1 is degraded by CPAF in C. trachomatis-infected cells. Further studies suggest that nectin-1 is the most likely candidate involved in triggering HSV-induced chlamydial persistence. Co-infection experiments using nectin-1-specific HSV-1 mutants suggest that nectin-1 is, indeed, required for persistence induction. Additional studies in single co-receptor-expressing CHO cells demonstrate that, despite the fact that HSV-1 enters both HVEM- and nectin-1-expressing cells, viral co-infection reduces chlamydial infectivity only in the CHO-nectin-1 cell line. These data confirm that HSV/nectin-1 interaction is sufficient for chlamydial persistence induction. Although nectin-1 ligation is known to activate Cdc42, pull-down assays indicate that Cdc42 is not activated in co-infected HeLa cells. Taken together, these data suggest that: i) HSV gD-nectin-1 binding activates a novel host epithelial cell pathway that restricts chlamydial development and ii) the chlamydiae may degrade nectin-1 to evade this inhibitory host response.
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Garcia, Knight Miguel Antonio. "T cell responses in Kenyan infants : impact on HIV-1 evolution during infection and an assessment of vaccine-induced memory responses in HIV-exposed uninfected infants." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:70672d43-7f08-456b-8c8b-12ba2432d5b8.
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The past 10 years has seen mother to child transmission (MTCT) of HIV-1 shift from being one of the predominant forces in the global epidemic to a phenomenon that is largely preventable and envisioned as being on the path to elimination. This thesis is based on two cohorts of Kenyan infants recruited before and after the development of effective antiretroviral interventions to prevent MTCT. Two main lines of enquiry are pursued with the aim to contribute to improved health outcomes of infants affected by HIV-1. The first seeks to further our understanding of the capacity of the infant cytotoxic T lymphocyte (CTL) response to influence viral evolutionary dynamics in early infection. Chapter 3 presents a modern phylogenetic analysis of longitudinal viral sequences derived from infants following in utero or peripartum infection. The results indicate that despite high levels of viral replication, infant CTL selection pressure plays a significant role in shaping early viral evolution. The second stems from an accumulating body of evidence that suggests that infants born to HIV-1 infected mothers who themselves are free from infection, termed HIV-1 exposed uninfected (HEU) infants, nevertheless face significantly higher rates of infectious disease- associated morbidity and mortality than HIV-1 unexposed infants. This study therefore sought to characterise the immunological status of HEU infants with particular emphasis on the phenotypic and functional properties of the T cell compartment. Chapter 4 presents the immunological characterisation of a cohort of healthy Kenyan infants recruited as a control population at two time points in early life. Chapter 5 present a cross-sectional comparison of HEU and control infant cohorts. The results suggest a level of altered immunological reactivity with respect to the T helper type 1 (Th1) response to polyclonal stimulation. In addition a compromised memory Th1 response was observed following polyclonal stimulation and following stimulation with Bacillus Calmette-Guerin and tetanus toxoid vaccine antigens.
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Jaggard, Daniel Andrew William. "The structure and function of RPW8.1 and RPW8.2, powdery mildew disease resistance proteins from Arabidopsis thaliana (L.) Heyhn." Thesis, University of East Anglia, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251898.
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Borrow, Persephone. "Immune responses in Theiler's murine encephalomyelitis virus-induced demyelinating disease." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257932.
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Muralidharan, Abenaya. "Towards Better Understanding of Respiratory Syncytial Virus (RSV) Vaccine-Induced Enhanced Disease." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39216.
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Pennycook, Alasdair Michael James. "The role of chemokines in lung disease induced by respiratory syncytial virus infection." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271456.
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Withers, David R. "Immunoglobulin diversification in immunosuppression induced by infectious bursal disease virus : the ICIQ-SF." Thesis, University of Bristol, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399962.
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Zamzami, Omar M. "Epstein-Barr Virus (EBV) latent membrane protein 1 (LMP1) peptides as inducers of regulatory cells to treat autoimmune haemolytic anaemia." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources. Online version available for University member only until May, 2014, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=59565.
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Lu, Rui. "High throughput virus induced gene silencing for the analysis of disease resistance in plants." Thesis, University of East Anglia, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398556.
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Du, Preez Jacques. "The development and characterisation of grapevine virus-based expression vectors." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4003.
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Thesis (PhD (Genetics))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: Grapevine (Vitis vinifera L.) is a very important agricultural commodity that needs to be protected. To achieve this several in vivo tools are needed for the study of this crop and the pathogens that infect it. Recently the grapevine genome has been sequenced and the next important step will be gene annotation and function using these in vivo tools. In this study the use of Grapevine virus A (GVA), genus Vitivirus, family Flexiviridae, as transient expression and VIGS vector for heterologous protein expression and functional genomics in Nicotiana benthamiana and V. vinifera were evaluated. Full-length genomic sequences of three South African variants of the virus (GTR1-1, GTG11-1 and GTR1-2) were generated and used in a molecular sequence comparison study. Results confirmed the separation of GVA variants into three groups, with group III (mild variants) being the most distantly related. It showed the high molecular heterogeneity of the virus and that ORF 2 was the most diverse. The GVA variants GTG11-1, GTR1-2 and GTR1-1 were placed in molecular groups I, II and III respectively. A collaboration study investigating the molecular divergence of GVA variants linked to Shiraz disease (SD), described two interesting GVA variants of group II, namely GTR1-2 and P163-M5 (Goszczynski et al., 2008). The group II variants were found to be closely linked to the expression of SD. GTR1-2 was isolated from a susceptible grapevine plant that never showed SD symptoms (Goszczynski 2007). The P163-M5 variant that resulted in exceedingly severe symptoms in N. benthamiana and is that used as SD positive control by the grapevine industry, was found to contain a 119 nt insert within the native ORF2. Comparative analysis performed on the complete nt and aa sequences of group II GVA variants suggested that the components in the GVA genome that cause pathogenicity in V. vinifera are more complex (or different) to those that cause pathogenicity in N. benthamiana. The three South African variants (GTR1-1, GTG11-1 and GTR1-2) were assembled into fulllength cDNA clones under control of CaMV 35S promoters. After several strategies were attempted, including a population cloning strategy for GTR1-2, none of the clones generated were able to replicate in N. benthamiana plants. A single amino acid substitution at position 13 (Tyr/Y Cys/C) in ORF 5 of the GTR1-2 cDNA clone was shown to abolish or reduce replication of the virus to below a detectable level. Two infectious clones of Israeli variants of GVA (T7-GVA-GR5 and T7-GVA118, obtained from M. Mawassi) were brought under control of a CaMV 35S promoter (35S-GVA-GR5 and 35S-GVA118). Both clones were infectious, able to replicate, move systemically and induce typical GVA symptoms after agroinfiltration in N. benthamiana. These Israeli clones served as backbone for further experiments in characterisation of transient expression and VIGS vectors. The use of GVA as gene insertion vector (35S-GVA118) and gene exchange vector (35S-GVA-GR5- ORF2+sgMP) in N. benthamiana and V. vinifera was compared. The gene insertion vector, 35S-GVA118 was based on the full-length GVA genome. The gene exchange vector, 35SGVA- GR5- ORF2+sgMP, was constructed in this study by elimination of ORF 2 and insertion of a sgMP and unique restriction sites to facilitate transgene insertion. In N. benthamiana both vectors showed similar GUS expression levels and photobleaching symptoms upon virus-induced NbPDS silencing. In V. vinifera limited GUS expression levels and VIGS photobleaching symptoms were observed for the gene insertion vector, 35SGVA118. No GUS expression was observed for the gene exchange vector 35S-GVA-GR5- ORF2+sgMP in this host. As for silencing, one plant, agroinfiltrated with 35S-GVA-GR5- ORF2-VvPDS+sgMP, developed photobleaching symptoms in 3 systemic infected leaves after 4 months. This study showed that GVA can be used as gene insertion and gene exchange vector for expression and VIGS in N. benthamiana, but in grapevine its use is limited to expression and silencing of genes in the phloem tissue. It is also the first report that ORF 2 of GVA is not needed for long distance movement in grapevine. To investigate the possible role of the P163-M5 119 nt insertion and the GVA ORF 2 (of unknown function), in expression of symptoms in plants, ORF 2 of a 35S-GVA-GR5 cDNA clone was removed and subsequently substituted by the corresponding ORFs of four South African GVA variants. Upon agro-infiltration into N. benthamiana leaves, all chimaeric GVA constructs were able to move systemically through the plant. At this stage no correlation could be found between severity of symptoms, the presence of the P163-M5 insert and the specific GVA ORF 2 present in the chimaeras, indicating that other factors in the viral genome or the host plant probably play a crucial role. This study contributed to the pool of available in vivo tools for study and improvement of the valuable grapevine crop. It also opened several exciting research avenues to pursue in the near future.
AFRIKAANSE OPSOMMING: Wingerd (Vitis vinifera L.) is ‘n baie belangrike landboukundige gewas wat beskerm moet word. Om die rede word verskeie in vivo gereedskap vir die bestudering van die wingerdplant, en die patogene wat dit infekteer benodig. Die wingerd genoom se volgorde is bepaal en dus is die volgende logiese stap om die gene te annoteer en funksie daaraan toe te skryf. In hierdie studie is die gebruik van Grapevine virus A (GVA), genus Vitivirus, familie Flexiviridae, as tydelike uitdrukking- en virus-geinduseerde geenuitdowingsvektor vir heteroloë proteïen uitdrukking en funksionele genoomstudies in Nicotiana benthamiana en V. Vinifera getoets. Vollengte genoomvolgordes van drie Suid-Afrikaanse variante van die virus (GTR1-1, GTG11-1 en GTR1-2) is gegenereer en in ‘n molekulêre volgorde vergelyking studie gebruik. Resultate het die verdeling van GVA variante in drie groepe, waar groep III die verste verwant is, bevestig. Dit het ook gewys dat die virus ‘n baie hoë molekulêre heterogeniteit het en dat oopleesraam 2 (ORF 2) die mees divers is. ‘n Samewerking studie waar die molekulêre diversiteit van GVA variante, gekoppel aan Shiraz siekte (SD), ondersoek is, is twee interessante variante van groep II beskryf, naamlik GTR1-2 en P163-M5 (Goszczynski et al., 2008). Groep II variante is vooraf gevind om nou verwant te wees aan die ontwikkeling van SD in wingerd. Die GTR1-2 variant is uit ’n vatbare wingerd plant, wat nooit SD-simptome vertoon het nie, geïsoleer (Goszczynski et al., 2007). In die ORF 2 van die P163-M5 variant, wat simptome van die ergste graad in N. benthamiana geïnduseer het, en ook deur die industrie as betroubare SD-positiewe kontrole gebruik word, is ’n 119 nt invoeging gevind. Die vergelykende analise wat uitgevoer is, het daarop gedui dat die determinante van patogenisiteit in die GVA genoom moontlik meer kompleks kan wees in V. vinifera as in N. benthamiana. Die drie Suid-Afrikaanse variante (GTR1-1, GTG11-1 en GTR1-2) is in afsonderlike vollengte cDNA klone, onder beheer van CaMV 35S promotors, aanmekaargesit. Nadat verskeie kloneringstrategieë, insluitend ’n populasie kloneringstrategie vir die GTR1-2 kloon, gebruik is, het geen een van die cDNA klone die vermoë besit om in N. benthamiana te repliseer nie. ’n Enkele aminosuur substitusie in posisie 13 (Tyr/Y Cys/C) in ORF 5 van die GTR1-2 kloon, het die replisering van die virus tot laer as ’n opspoorbare vlak verlaag. Twee infektiewe klone van Israeliese GVA variante (T7-GVAGR5 en T7-GVA118, verkry van M. Mawassi) is onder beheer van ‘n CaMV 35S promotor geplaas (35S-GVA-GR5 and 35S-GVA118). Beide klone het na agro-infiltrasie in N. benthamiana plante gerepliseer, sistemies beweeg en tipiese GVA simptome geinduseer. Hierdie twee klone het as raamwerk gedien vir verdere eksperimente in karakterisering van tydelike uitdrukkings- en VIGS vektore. Die gebruik van GVA as geen-insvoegingsvektor (35S-GVA118) en geen-vervangingsvektor (35S-GVA-GR5- ORF2+sgMP) is in N. benthamiana en V. vinifera vergelyk. Die geen-invoegingsvektor 35S-GVA118, was op die vollengte GVA genoom gebasseer. Die geen-vervangingsvektor 35S-GVA-GR5- ORF2+sgMP, was in hierdie studie gekonstrueer. Dit is gemaak eerstens deur eliminasie van ORF 2 in die 35S-GVA-GR5 kloon, en tweedens deur die invoeging van ’n subgenomiese promotor van die beweginsproteïen (sgMP) en unieke beperkings-ensiemsetels om klonering van transgene te fasiliteer. Beide vektore het in N. benthamiana vergelykbare GUS uitdrukkingsvlakke en fotobleikende simptome getoon na virus-geinduseerde NbPDS uitdowing. In V. Vinifera is beperkte GUS uitdrukkingsvlakke en VIGS fotobleikende simptome opgemerk met die geen-invoegingsvektor, 35S-GVA118. Geen GUS uitdrukking is in hierdie gasheerplant met die geen-vervangingsvektor opgemerk nie. Slegs een wingerdplant het fotobleikende simptome, na 4 maande in 3 sistemies geïnfekteerde blare gewys, na agroinfiltrasie van die 35S-GVA-GR5- ORF2-VvPDS+sgMP konstruk. Hierdie studie het bevestig dat GVA as geen-invoeging en geen-vervangingsvektor, vir heteroloë proteïenuitdrukking en VIGS, in N. benthamiana gebruik kan word, maar dit blyk of die gebruik daarvan in wingerd meer tot die floeëm weefsel beperk is. Hierdie studie wys vir die eerste keer dat ORF 2 nie nodig is vir langafstand beweging van die virus in wingerd nie. Om die moontlike rol van die P163-M5 119 nt invoeging en die GVA ORF 2 (met onbekende funksie), in die uitdrukking van simptome in plante te ondersoek, is ORF 2 van die 35SGVA- GR5 cDNA kloon verwyder en daaropvolgens vervang met die ooreenstemmende ORFs van vier Suid-Afrikaanse GVA variante. Na agro-infiltrasie in N. benthamiana blare, het al die chimeras die vermoë gehad om te repliseer, sistemies te beweeg en simptome te induseer. Geen korrelasie kon gevind word tussen die graad van simptome, die teenwoordigheid van die P163-M5 insersie en die spesifieke GVA ORF 2 teenwoordig in die chimeras nie, wat dus daarop dui dat ander faktore in die virusgenoom of die gasheerplant `n moontlike belangrike rol kan speel. Hierdie studie het bygedrae tot die beskikbare poel van in vivo gereedskap vir die bestudering en verbetering van die kosbare wingerdgewas. Dit het ook talle interessante navorsingsgeleenthede oopgemaak om in die nabye toekoms te betree.
23
Khidr, Yehia. "Development of a strategy to induce RNA-silencing in squash against virus diseases by genetic transformation." [S.l. : s.n.], 2007. http://nbn-resolving.de/urn:nbn:de:bsz:100-opus-1963.
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Boyden, Alexander Wiser. "Influenza A virus induces regulated T cell-driven B cell responses." Diss., University of Iowa, 2012. https://ir.uiowa.edu/etd/3432.
Full textAbstract:
Protection from influenza A virus (IAV) challenge requires switched, high affinity Abs derived from long-lived memory B cells and plasma cells. These subsets are generated in germinal centers (GCs), hallmark structures of T helper cell-driven B cell immunity. A full understanding of the acute and persistent GC B cell reaction following respiratory IAV infection is lacking, as is the characterization of IAV-induced T follicular helper (TFH) cells that support GCs. Additionally, it remains unclear as to whether IAV-induced GC B cells are subject to control by regulatory T cells (Tregs). To address this, GC B cell and TFH cell responses were analyzed in mice following pulmonary challenge with IAV. Studies demonstrated that marked GC reactions were induced in lung-draining lymph nodes (dLNs), lung, spleen and nasal-associated lymphoid tissue (NALT), although the magnitude, kinetics, and isotype switching patterns of the response was site-specific, and largely depended on the magnitude of IAV-induced TFH cell populations. TFH cell magnitude peaked prior to that of GC B cells in all tissues, and TFH cells purified from dLNs generated IL-21 and IFN-gamma upon activation, although CD4+CXCR5- T effector cells produced higher levels of all cytokines. IgA+ GC B cells were infrequent in most sites, but composed a significant subset of the switched GC population in NALT. Further, splenectomized mice withstood a lethal recall challenge, suggesting the spleen to be unnecessary for long-term protection. Additionally, GC B cell populations were analyzed at distal time points to assess the understudied, persistent GC B cell response after IAV infection. Our analysis demonstrated that persistent GC B cell populations in mouse lungs directly correlated with infectious dose, pathogenicity of the virus, as well as the presence of long-term CD4+ T cell help. Finally, experiments showed that Tregs contribute to the control of GCs induced in the spleen by IAV challenge. This was demonstrated by a marked increase in the number of total and switched GC B cell numbers when Tregs were either depleted or disrupted in vivo proximal to IAV exposure.
25
Lin, Yongping, and 林勇平. "Small interfering RNAs with a novel motif potently induce an early strong {221}-defensin 4 production which provides strong antiviraleffects." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B45817492.
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Barrios, Marrugo Kelly. "Therapeutic Peptide-Based Vaccination Strategies Against HPV-Induced Cancers." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4283.
Full textAbstract:
There is an urgent need for the development of an effective therapeutic vaccine against cancer caused by human papilloma virus (HPV). We focused on HPV-induced malignancies because of their high worldwide prevalence (e.g., cervical carcinoma and head & neck cancer). A successful therapeutic vaccine could prevent the 250 000 deaths/year worldwide and the 2.25 billion dollars that
are expended in related care in the US.
We used an HPV-induced mouse cancer model to test vaccines
composed of a CD8 T cell peptide epitope administered with potent adjuvants designed to generate vast numbers of high avidity cytotoxic T lymphocytes specific for the HPV16-E7 antigen. One vaccination strategy (TriVax) consists of intravenous administration of synthetic peptide HPV16-E749-57 administered together with a Poly-IC (a TLR3 agonist) and anti-CD40 monoclonal antibody(αCD40 mAb) while the second more simple strategy (BiVax) comprises solely of peptide plus Poly-IC. We used an E7 peptide as antigen in the vaccination strategies because expression of the viral E6 and E7 proteins is required to maintain oncogenic phenotype and because normal cells do not express E6/E7, therefore a therapeutic vaccine targeting these proteins has several advantages:
a) a strong immune response can be induced since immune tolerance to these foreign antigens does not exist and b) the strong immune response should not inflict damage to normal cells.
TriVax and BiVax generate a high number of antigen specific CD8 T cells capable clear subcutaneous tumors and prevent recurrences, both vaccines are efficient through the i.v. and i.m. route. TriVax (prime-boost) clears tumor in 100% of mice while BiVax clears tumor in 50% of mice, this differential effect is due to the number of antigen specific CD8 T cells and increasing the number of booster shot makes BiVax as immunogenic and efficient in clearing tumors. In the absence of type-I IFN signaling (in IFNαΒR KO mice), TriVax is less effective in generating sufficient numbers of CD8 T cells that could be necessary for total disease eradication. We observed a significant anti-tumor effect of TriVax in the absence of interferon gamma, however the cytokine may play some role in the overall effectiveness of TriVax to completely reject the tumors. Immune responses produced by BiVax are highly dependent on the simultaneous administration of peptide and Poly-IC, on the peptide composition, vaccine formulation and route of administration. The magnitude of the response is dependent on the expression of the Poly-IC receptors TLR3 and melanoma differentiation-associated protein 5 (MDA5). Interestingly, the magnitude and duration of the CD8 T cell responses generated by peptide and Poly-IC mixtures does not rely on the presence of CD4 T cells, scavenger receptor-A (SR-A) or type-I IFN signals and was minimally affected by the absence of CD40 signaling.
The present findings could facilitate the development of simple and effective subunit vaccines for diseases where CD8 T cells may hold a therapeutic benefit.
27
Le, Thanh Toan, Van Dien Luong, Thi Thuy Nhien Ngo, and Van Kim Pham. "Induced systemic resistance against rice grassy stunt virus – a promising field for ecological rice production." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-88491.
Full textAbstract:
Most rice protection methods have currently used toxic chemicals to control pathogens and pests, which leads to environmental pollution. Systemic acquired resistance (SAR) taking advantage of natural defence reaction of plants could be proposed as an alternative, ecologically friendly approach for plant protection. Its application into rice production could minimize the chemicals quantity used and could contribute to the decrease of environmental pollution and the development of sustainable agriculture. The research was conducted to select the most effective chemical and suitable method to improve the health of rice plants infected by grassy stunt disease in net-house of Can Tho University. SAR chemicals were used at very low concentrations (in mM). Results showed that the height of rice plants treated with SAR chemicals was higher than that of plants untreated. Besides, the number of diseased plants was reduced and the ratio of firm grain and yield increased when plants were applied by SAR. Among the used substances, oxalic acid provided the best systemic acquired resistance. With oxalic acid, seed soaking was better than seed coating in systemic acquired resistance against rice grassy stunt diseaseHầu hết các phương pháp sản xuất lúa hiện nay đều sử dụng các hóa chất độc hại trong việc phòng trừ bệnh và côn trùng gây hại, nên dẫn đến ô nhiễm môi trường. Kích thích tính kháng lưu dẫn giúp kích hoạt cơ chế tự nhiên kháng bệnh của cây có thể là giải pháp bảo vệ thực vật thay thế an toàn với môi trường. Việc ứng dụng tiến bộ này vào trong sản xuất lúa có thể làm giảm lượng hóa chất sử dụng, đóng góp vào việc giảm thiểu ô nhiễm môi trường và sự phát triển của một nền nông nghiệp bền vững. Nghiên cứu đã được thực hiện tại nhà lưới trường Đại học Cần Thơ để tuyển chọn hóa chất và phương pháp sử dụng hóa chất để tăng cường sức khỏe giúp cây lúa vượt qua bệnh vàng lùn. Hóa chất kích kháng được sử dụng ở một nồng độ rất thấp (đơn vị là mM). Kết quả cho thấy chiều cao cây lúa khi xử lý chất kích kháng tốt hơn so đối chứng không xử lý. Bên cạnh đó, số cây lúa nhiễm bệnh giảm, tỉ lệ hạt chắc và năng suất tăng khi cây lúa được xử lý với chất kích kháng. Trong số các chất kích kháng đã sử dụng, acid oxalic cho hiệu quả vượt trội. Với chất acid oxalic, phương pháp ngâm hạt cho hiệu quả kích kháng tốt hơn phương pháp áo hạt
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Giorgakoudi, Kyriaki. "Mathematical modelling of the potential determinants of foot-and-mouth disease virus-induced death of bovine epithelial cells." Thesis, Loughborough University, 2014. https://dspace.lboro.ac.uk/2134/14931.
Full textAbstract:
Foot-and-mouth disease virus (FMDV) is a highly infectious virus affecting cloven-hoofed animals. The most prominent of its clinical signs is the development of vesicular lesions on the feet and in or around the mouth, which are a consequence of extensive FMDV-induced epithelial cell death. Currently, there is no certain biological knowledge on why extensive epithelial cell death occurs in some FMDV-infected tissues, but not in others. Using the epithelial tissues of tongue and dorsal soft palate as examples of a tissue where lesions occur and one that does not visibly exhibit FMDV-induced cell death, this work aims to identify the potential drivers of epithelial cell death and survival. A partial differential equation (PDE) model informed by experimental data on epithelial structure, is used to test epithelium thickness and cell layer structure as potential determinants. A second PDE model investigates FMDV-interferon (IFN) dynamics and their impact on the levels of cell death and survival, while an experimental study is undertaken to provide data for model validation. The work carried out casts light on the important role of a variety of factors including FMDV replication, IFN production and release, and IFN antiviral action.
29
De, Oliveira Rodrigues Raquel. "Modulation of target cells induced by Crimean-Congo hemorrhagic fever virus : the contribution in the pathogenesis of the disease." Thesis, Lyon, École normale supérieure, 2012. http://www.theses.fr/2012ENSL0707.
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Le virus de la fièvre hémorragique de Crimée-Congo (VFHCC) est un virus transmis par des tiques, appartenant au genre Nairovirus de la famille des Bunyaviridae. Il est réparti sur plus d’une trentaine de pays de plusieurs continents : Europe, Asie et Afrique ; avec une mortalité moyenne estimée de 30%. Le VFHCC peut causer à l’homme une maladie hémorragique très sévère et parmi divers symptômes, il peut induire une inflammation aigüe et des lésions hépatiques. Les phagocytes mononucléaires, les hépatocytes et les cellules endothéliales ont été décrits comme étant des cellules cibles lors d’études cliniques et post-mortem ainsi que lors d’études en modèle murin. Nous avons analysé, lors d’étude in vitro, la réponse cellulaire de cellules présentatrices de l’antigène (CPAs) et d’hépatocytes humains. Afin de mieux comprendre la pathogenèse du VFHCC, nous avons comparé la réponse de ces cellules avec celle du virus Dugbe (DUGV), un nairovirus génétiquement le plus proche de VFHCC considéré comme faiblement pathogénique. Finalement, afin améliorer la détection de DUGV in vitro et lors d’études épidémiologiques de terrain, nous avons développé un test moléculaire en temps réel pour détecter et quantifier DUGV.Nous avons observé que le VFHCC induisait une réponse inflammatoire chez les CPAs, en revanche, DUGV induisait une réponse plus forte, ce qui suggère que VFHCC induirait une inhibition sélective de certains médiateurs de la réponse pro-inflammatoire. Lors de l’infection in vitro des hépatocytes par le VFHCC, nous avons observé que le virus induisait du stress du RE, l’activation de l’IL-8 un médiateur pro-inflammatoire, et la modulation des deux voies pro-apoptotiques. Quand nous avons comparé cette réponse à celle induite par DUGV nous avons trouvé que la différence majeure était l’absence d’apoptose. Ces différences pourraient, en partie, expliquer le rôle du foie dans la pathogenèse induite par le VFHCCCrimean-Congo hemorrhagic fever virus (CCHFV) is a widely distributed tick-borne member of the Nairovirus genus (Bunyaviridae) inducing an average mortality rate of 30% in humans. CCHFV induces a severe hemorrhagic disease in infected patients that includes, among other bleeding symptoms, acute inflammation and liver lesions. The mononuclear phagocytes, the hepatocytes and the endothelial cells were described to be the main target cells in both human clinical studies and animal model in vivo studies.We analysed the in vitro cellular response of host antigen presenting cells (APC) and hepatocytes. Then, to better elucidate the pathogenesis of CCHFV, we compared the response of these cells after infection with Dugbe virus (DUGV), a mild pathogenic virus genetically close to CCHFV. In order to improve DUGV detection in vitro and in field studies, we also developed a molecular real-time quantitative tool to detect and quantify DUGV.We found that CCHFV induced an inflammatory response in both APCs tested; however DUGV induced a higher cytokine/chemokine response in these target cells than CCHFV. Our results suggest that CCHFV was able to selectively inhibit the activation of some inflammatory mediators in the in vitro infection and that CCHFV/DUGV cellular response differences could be relevant in pathogenesis. On the other hand, when we in vitro infected hepatocytes with CCHFV, we observed that it was able to induce ER-stress, activate IL-8 secretion and modulate both mitochondrial and death receptor pathways of apoptosis. When we compared this cellular response with that induced by DUGV, we found that the most striking difference was the absence of apoptosis. These differences could, in part, explain the role of the liver in the pathogenesis induced by CCHFV
30
Bridges, James Patrick. "Disease-Linked Mutations in Surfactant Protein C (SP-C) Cause ER Stress and Increase Susceptibility to Viral-Induced Cell Death." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1132154885.
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Bozhanaj, Kreshnik. "The Effect Of Virus Induced Gene Silencing Of Fas Associated Factor1 In Blumeria Graminis Infected Barley." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12611139/index.pdf.
Full textAbstract:
Cereal loss due to fungal pathogens is an ongoing setback in agriculture. Elucidating plant&rsquos resistance and susceptibility mechanisms against these cereal killers, promises progress in agriculture. In the way of understanding barley resistance against fungus Blumeria Graminis we silenced FAS-Associated Factor 1 (FAF1) gene in its mRNA level with Virus Induced Gene Silencing (VIGS) technique. Previous research in our lab had shown an augmentation in mRNA levels of FAF1 gene in fungus infected wheat, suggesting a role of this gene in the resistance mechanism. We hypothesized that the apoptotic role of FAF1 protein in metazoan is conserved in plants by including FAF1 as a factor in hypersensitive response. Barley lines Pallas01 and Pallas03 which are respectively resistant and susceptible against fungus Blumeria graminis hordei 103 (Bgh103) were used for fungal inoculations after FAF1 silencing, to test if the hypersensitive response against fungus Bgh103 was prevented. In this aspect the formation of death lesions on the Pallas01 leaf due to fungal resistance was not prevented demonstrating that FAF1 silencing with VIGS in the resistant Pallas01 line of barley is not sufficient to stop apoptosis. On the other hand the FAF1-silenced barley susceptible line Pallas03 became more sensitive to fungal stress based on conidia (body part of the fungus) counting after trypan blue staining of the infected leaves. In the C-terminus of FAF1 an ubiquitin like domain-X (UBX) is found, which is the cause of stress sensitivity based on the reported data obtained about this domain&rsquo
s loss of function in other proteins. These results suggest that FAF1 is a catalyst in the hypersensitive response and its loss of function makes barley more susceptible to fungal stress. On the other hand a short mRNA homology was found among FAF1 and many pathogen disease related proteins making this homology a possible target site for VIGS of FAF1 generated siRNAs, which might cause some other protein to be responsible for the barley susceptibility against the fungus.
32
Murawski, Matthew R. "Respiratory Syncytial Virus (RSV) Induces Innate Immunity through Toll-Like Receptors and Acquired Immunity via the RSV G Protein: A Dissertation." eScholarship@UMMS, 2009. https://escholarship.umassmed.edu/gsbs_diss/432.
Full textAbstract:
Respiratory syncytial virus (RSV) causes a common infection that is associated with a range of respiratory illnesses from common cold-like symptoms to serious lower respiratory tract illnesses such as pneumonia and bronchiolitis. RSV is the single most important cause of serious lower respiratory tract illness in children < 1 year of age. Host innate and acquired immune responses activated following RSV infection have been suspected as contributing to RSV disease. Toll-like receptors (TLRs) activate innate and acquired immunity and are candidates for playing key roles in the host immune response to RSV. Leukocytes express TLRs including TLR2, TLR6, TLR3, TLR4, and TLR7 that can potentially interact with RSV and promote immune responses following infection. Using knockout mice, we have demonstrated that TLR2 and TLR6 signaling in leukocytes can activate innate immunity against RSV by promoting TNF-α, IL-6, CCL2 (MCP-1), and CCL5 (RANTES) production. As previously noted, TLR4 also contributed to cytokine activation (71, 90). Furthermore, we demonstrated that signals generated following TLR2 and TLR6 activation were important for controlling viral replication in vivo. Additionally, TLR2 interactions with RSV promoted neutrophil migration and dendritic cell activation within the lung. Collectively, these studies indicate that TLR2 is involved in RSV recognition and subsequent innate immune activation and may play a role in modulating acquired immune responses through DCs.
Despite the fact that RSV is the single most important cause of infant upper respiratory tract disease, there are no licensed vaccines available to prevent RSV disease. We have developed a virus-like particle (VLP) vaccine candidate for RSV. The VLP is composed of the NP and M proteins of Newcastle disease virus (NDV) and a chimera protein containing the cytoplasmic and transmembrane domains of the NDV HN protein and the ectodomain of the human RSV G protein (H/G). BALB/c mice immunized with 10 or 40 μg total VLP-H/G protein by intraperitoneal or intramuscular inoculation stimulated antibody responses to G protein as good as or better than comparable amounts of UV-inactivated RSV. Furthermore, VLP-H/G induced robust CTL responses in vaccinated animals. Immunization with two or even a single dose of these particles resulted in the complete protection of BALB/c mice from RSV replication in the lungs. Upon RSV challenge of VLP-H/G immunized mice, no enhanced pathology in the lungs was observed, although lungs of mice immunized in parallel with formalin-inactivated RSV (FI-RSV) showed the significant pathology that has been previously observed with FI-RSV vaccination. Thus, the VLP-H/G candidate vaccine was immunogenic in BALB/c mice and prevented replication of RSV in murine lungs with no evidence of immunopathology. These data support further development of virus-like particle vaccine candidates for RSV.
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Qaisar, Natasha. "Innate Immune Signaling Drives Pathogenic Events Leading to Autoimmune Diabetes." eScholarship@UMMS, 2018. https://escholarship.umassmed.edu/gsbs_diss/973.
Full textAbstract:
Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by the immune-mediated destruction of insulin-producing beta-cells of pancreatic islets, culminating in critical insulin deficiency. Both genetic and environmental factors likely orchestrate an immune-mediated functional loss of beta cell mass, leading to the clinical manifestation of disease and lifelong dependence on insulin therapy. Additional evidence suggests the role of innate and adaptive immune mechanisms leading to inflammation in beta cells mediated by proinflammatory cytokines and chemokines, activation of beta-cell-reactive T cells,and failure of immune tolerance. Viral infections have been proposed as causal determinants or initiating triggers for T1D but remain unproven. Understanding the relationship between viral infections and the development of T1D is essential for T1D prevention. Importantly, virus-induced innate immune responses, particularly type I interferon (IFN-I, IFN-a/b), have been implicated in the initiation of islet autoimmunity and development of T1D. The goal of my thesis project is to investigate how the IFN-I signaling pathway affects the development of T1D using the LEW.1WR1 rat model of autoimmune diabetes. My hypothesis is that disrupting IFN-Isignaling via functional deficiency of the IFN-I interferon receptor (IFNAR) prevents or delays the development of virus-induced diabetes.For this purpose, I generated IFNAR subunit 1(IFNAR1)-deficient LEW.1WR1 rats using CRISPR-Cas9 genome editing and confirmed the functional disruption of IFNAR1. The absence of IFNAR1 results in a significant delay in onset and frequency of diabetes following poly I:C challenge and reduces the incidence of insulitis after poly I:C treatment. The frequency of diabetes induced by Kilham rat virus (KRV) is also reduced in IFNAR1-deficient LEW.1WR1 rats. Furthermore, I observe a decrease in CD8+T cells in spleens from KRV-infected IFNAR1-deficient rats relative to that in KRV-infected wild-type rats. While splenic regulatory T cells are depleted in WT rats during KRV-infection, no such decrease is observed in KRV-infected IFNAR1-deficient rats. A comprehensive bulk RNA-seq analysis reveals a decrease of interferon-stimulated genes and inflammatory gene expression in IFNAR1-deficient rats relative to wild-type rats following KRV challenge. Collectively, the results from these studies provided mechanistic insights into the essential role of virus-induced, IFN-I-initiated innate immune responses in the early phase of autoimmune diabetes pathogenesis.
34
Tavares, Lucas Alves. "O envolvimento da proteína adaptadora 1 (AP-1) no mecanismo de regulação negativa do receptor CD4 por Nef de HIV-1." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/17/17136/tde-06012017-113215/.
Full textAbstract:
O Vírus da Imunodeficiência Humana (HIV) é o agente etiológico da Síndrome da Imunodeficiência Adquirida (AIDS). A AIDS é uma doença de distribuição mundial, e estima-se que existam atualmente pelo menos 36,9 milhões de pessoas infectadas com o vírus. Durante o seu ciclo replicativo, o HIV promove diversas alterações na fisiologia da célula hospedeira a fim de promover sua sobrevivência e potencializar a replicação. A rápida progressão da infecção pelo HIV-1 em humanos e em modelos animais está intimamente ligada à função da proteína acessória Nef. Dentre as diversas ações de Nef está a regulação negativa de proteínas importantes na resposta imunológica, como o receptor CD4. Sabe-se que esta ação resulta da indução da degradação de CD4 em lisossomos, mas os mecanismos moleculares envolvidos ainda são totalmente elucidados. Nef forma um complexo tripartite com a cauda citosólica de CD4 e a proteína adaptadora 2 (AP-2), em vesículas revestidas por clatrina nascentes, induzindo a internalização e degradação lisossomal de CD4. Pesquisas anteriores demonstraram que o direcionamento de CD4 aos lisossomos por Nef envolve a entrada do receptor na via dos corpos multivesiculares (MVBs), por um mecanismo atípico, pois, embora não necessite da ubiquitinação de carga, depende da ação de proteínas que compõem os ESCRTs (Endosomal Sorting Complexes Required for Transport) e da ação de Alix, uma proteína acessória da maquinaria ESCRT. Já foi reportado que Nef interage com subunidades dos complexos AP-1, AP-2, AP-3 e Nef não parece interagir com subunidades de AP-4 e AP-5. Entretanto, o papel da interação de Nef com AP-1 e AP-3 na regulação negativa de CD4 ainda não está totalmente elucidado. Ademais, AP-1, AP-2 e AP-3 são potencialmente heterogêneos devido à existência de isoformas múltiplas das subunidades codificadas por diferentes genes. Todavia, existem poucos estudos para demonstrar se as diferentes combinações de isoformas dos APs são formadas e se possuem propriedades funcionais distintas. O presente trabalho procurou identificar e caracterizar fatores celulares envolvidos na regulação do tráfego intracelular de proteínas no processo de regulação negativa de CD4 induzido por Nef. Mais especificamente, este estudo buscou caracterizar a participação do complexo AP-1 na modulação negativa de CD4 por Nef de HIV-1, através do estudo funcional das duas isoformas de ?-adaptina, subunidades de AP-1. Utilizando a técnica de Pull-down demonstramos que Nef é capaz de interagir com ?2. Além disso, nossos dados de Imunoblot indicaram que a proteína ?2-adaptina, e não ?1-adaptina, é necessária no processo de degradação lisossomal de CD4 por Nef e que esta participação é conservada para degradação de CD4 por Nef de diferentes cepas virais. Ademais, por citometria de fluxo, o silenciamento de ?2, e não de ?1, compromete a diminuição dos níveis de CD4 por Nef da membrana plasmática. A análise por imunofluorêsncia indireta também revelou que a diminuição dos níveis de ?2 impede a redistribuição de CD4 por Nef para regiões perinucleares, acarretando no acúmulo de CD4, retirados por Nef da membrana plasmática, em endossomos primários. A depleção de ?1A, outra subunidade de AP-1, acarretou na diminuição dos níveis celulares de ?2 e ?1, bem como, no comprometimento da eficiente degradação de CD4 por Nef. Além disso, foi possível observar que, ao perturbar a maquinaria ESCRT via super-expressão de HRS (uma subunidade do complexo ESCRT-0), ocorreu um acumulo de ?2 em endossomos dilatados contendo HRS-GFP, nos quais também detectou-se CD4 que foi internalizado por Nef. Em conjunto, os resultados indicam que ?2-adaptina é uma importante molécula para o direcionamento de CD4 por Nef para a via ESCRT/MVB, mostrando ser uma proteína relevante no sistema endo-lisossomal. Ademais, os resultados indicaram que as isoformas ?-adaptinas não só possuem funções distintas, mas também parecem compor complexos AP-1 com diferentes funções celulares, já que apenas a variante AP-1 contendo ?2, mas não ?1, participa da regulação negativa de CD4 por Nef. Estes estudos contribuem para o melhor entendimento dos mecanismos moleculares envolvidos na atividade de Nef, que poderão também ajudar na melhor compreensão da patogênese do HIV e da síndrome relacionada. Em adição, este trabalho contribui para o entendimento de processos fundamentais da regulação do tráfego de proteínas transmembrana no sistema endo-lisossomal.The Human Immunodeficiency Virus (HIV) is the etiologic agent of Acquired Immunodeficiency Syndrome (AIDS). AIDS is a disease which has a global distribution, and it is estimated that there are currently at least 36.9 million people infected with the virus. During the replication cycle, HIV promotes several changes in the physiology of the host cell to promote their survival and enhance replication. The fast progression of HIV-1 in humans and animal models is closely linked to the function of an accessory protein Nef. Among several actions of Nef, one is the most important is the down-regulation of proteins from the immune response, such as the CD4 receptor. It is known that this action causes CD4 degradation in lysosome, but the molecular mechanisms are still incompletely understood. Nef forms a tripartite complex with the cytosolic tail of the CD4 and adapter protein 2 (AP-2) in clathrin-coated vesicles, inducing CD4 internalization and lysosome degradation. Previous research has demonstrated that CD4 target to lysosomes by Nef involves targeting of this receptor to multivesicular bodies (MVBs) pathway by an atypical mechanism because, although not need charging ubiquitination, depends on the proteins from ESCRTs (Endosomal Sorting Complexes Required for Transport) machinery and the action of Alix, an accessory protein ESCRT machinery. It has been reported that Nef interacts with subunits of AP- 1, AP-2, AP-3 complexes and Nef does not appear to interact with AP-4 and AP-5 subunits. However, the role of Nef interaction with AP-1 or AP-3 in CD4 down-regulation is poorly understood. Furthermore, AP-1, AP-2 and AP-3 are potentially heterogeneous due to the existence of multiple subunits isoforms encoded by different genes. However, there are few studies to demonstrate if the different combinations of APs isoforms are form and if they have distinct functional properties. This study aim to identify and characterize cellular factors involved on CD4 down-modulation induced by Nef from HIV-1. More specifically, this study aimed to characterize the involvement of AP-1 complex in the down-regulation of CD4 by Nef HIV-1 through the functional study of the two isoforms of ?-adaptins, AP-1 subunits. By pull-down technique, we showed that Nef is able to interact with ?2. In addition, our data from immunoblots indicated that ?2- adaptin, not ?1-adaptin, is required in Nef-mediated targeting of CD4 to lysosomes and the ?2 participation in this process is conserved by Nef from different viral strains. Furthermore, by flow cytometry assay, ?2 depletion, but not ?1 depletion, compromises the reduction of surface CD4 levels induced by Nef. Immunofluorescence microscopy analysis also revealed that ?2 depletion impairs the redistribution of CD4 by Nef to juxtanuclear region, resulting in CD4 accumulation in primary endosomes. Knockdown of ?1A, another subunit of AP-1, resulted in decreased cellular levels of ?1 and ?2 and, compromising the efficient CD4 degradation by Nef. Moreover, upon artificially stabilizing ESCRT-I in early endosomes, via overexpression of HRS, internalized CD4 accumulates in enlarged HRS-GFP positive endosomes, where co-localize with ?2. Together, the results indicate that ?2-adaptin is a molecule that is essential for CD4 targeting by Nef to ESCRT/MVB pathway, being an important protein in the endo-lysosomal system. Furthermore, the results indicate that ?-adaptins isoforms not only have different functions, but also seem to compose AP-1 complex with distinct cell functions, and only the AP-1 variant comprising ?2, but not ?1, acts in the CD4 down-regulation induced by Nef. These studies contribute to a better understanding on the molecular mechanisms involved in Nef activities, which may also help to improve the understanding of the HIV pathogenesis and the related syndrome. In addition, this work contributes with the understanding of primordial process regulation on intracellular trafficking of transmembrane proteins.
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Stone, Amy Elizabeth Seymour. "The role of interleukin-12 in the pathogenesis of Sendai virus-induced airway disease /." 2002. http://purl.fcla.edu/fcla/etd/UFE0000613.
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Chiang, Huan Jung, and 江歡容. "The Effects of Nanobacteria-like particles on viral infections and virus-induced diseases." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/464j3k.
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Hansberger, Mark William. "Viral and cellular determinants of reovirus-induced NF-[kappa]B activation and apoptosis." Diss., 2006. http://etd.library.vanderbilt.edu/ETD-db/available/etd-10202006-172315/.
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Bao, Kogan K. "Kinetic analysis of avian sarcoma virus integrase in the presteady-state." Thesis, 2002. http://hdl.handle.net/1957/30239.
Full textAbstract:
Integrase catalyzes insertion of a retroviral genome into the host chromosome.
Following reverse transcription, integrase binds specifically to the ends of the duplex retroviral
DNA, endonucleolytically cleaves two nucleotides from each 3'-end (the processing activity),
and inserts these ends into the host DNA (the joining activity) in a concerted manner.
Additionally, it has been observed that integrase can catalyze the removal of inserted viral ends
(the disintegration activity) in vitro. Presteady-state experiments were performed using synapsed
substrates to probe the processing reaction and a disintegration substrate to determine the
number of protomers in a functional multimeric complex. In single-turnover studies, a novel
"splicing" reaction was observed that revealed complications with accurate quantification of
enzymatic activity using the synapsed substrates. The splicing reaction was further used to gain
insight into the selection of nucleophiles and electrophiles at the binding site. To reduce the
complexity introduced by the integrase-catalyzed splicing reaction, 5'-5' reverse-polarity
synapsed substrates were designed that were not susceptible to the splicing reaction and that
allowed direct comparison of LTR ends simultaneously bound at the active site. Analysis of the
presteady-state assays using these reverse-polarity substrates revealed that the concurrent binding
of the biologically relevant U3/U5 combination of viral ends facilitates maximal activity of the
processing reaction. A disintegration substrate was used in presteady-state active site titrations to
determine a reaction stoichiometry of four integrase protomers per one substrate molecule for
the disintegration reaction. A tetrameric active complex was then confirmed using atomic force
microscopy to image integrase-DNA complexes during the first catalytic turnover. The
observed increase of the tetramer population in the presence of substrate DNA demonstrates that
the binding of the disintegration substrate induces assembly of the active tetramer and suggests
that tetramer assembly may be an integral and dynamic component of the catalytic pathway.Graduation date: 2003
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Busto, Jennifer Lee. "Transcriptional changes in Nicotiana benthamiana induced by tobamoviral transfection." Thesis, 2005. http://proquest.umi.com/pqdweb?index=1&did=913527421&SrchMode=1&sid=1&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1235524057&clientId=23440.
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Abraham, Sojan. "Japanese Encephalitis Virus Infection In Vitro : Role Of Type-I Interferons And NF-kB In The Induction Of Classical And Nonclassical MHC-I Molecules." Thesis, 2009. http://hdl.handle.net/2005/1087.
Full textAbstract:
Japanese encephalitis virus (JEV) is one of the major causes of encephalitis in Asia. JEV causes serious inflammation of the brain, which may lead to permanent brain damage and has a high mortality rate. Almost 3 billion people live in JE endemic areas and JEV causes an estimated 20,000 cases of disease and 6000 deaths per year. JEV is a positive stranded RNA virus belonging to the Flavivirus genus of the family Flaviviridae. The genome of JEV is about 11 kb long and codes for a polyprotein which is cleaved by both host and viral encoded proteases to form 3 structural and 7 non-structural proteins. JEV transmission occurs through a zoonotic cycle involving mosquitoes and vertebrate amplifying hosts, chiefly pigs and ardeid birds. Humans are infected when bitten by an infected mosquito and are dead end hosts. The role of humoral and cell mediated immune responses during JEV infection have been studied by several groups. While the humoral responses play a central role in protection against JEV, the cell mediated immune responses contributing to this end are not fully understood.
The MHC molecules have been known to play predominant roles in host responses to viral infections and the consequences of virus infection on the expression of MHC molecules are varied. The expression of MHC-I molecules is known to decrease upon infection with many viruses such as HIV, MCMV, HCMV, Adv, and EBV. In contrast, infection with flavivirus such as West Nile Virus (WNV) has been shown to increase the cell surface expression of both MHC-I and MHC-II molecules. It has been reported previously that WNV infection increases the cell surface expression of adhesion molecules such as ICAM-1, VCAM-1 as well as E-Selectin and these changes were mediated directly by WNV and not by soluble cytokines.
In contrast to classical MHC-I molecules, the nonclassical MHC-I molecules do not belong to a single group of structurally and functionally homologous proteins and normally have lower cell surface expression. Earlier studies have shown that the expression of nonclassical MHC-I molecules were induced during infection with JHM strain of mouse hepatitis virus (MHV). However, the functional significance of this induction is unclear. Expression of nonclassical MHC-I molecules upon flaviviral infection is not very well understood.
In this thesis, evidence is presented that JEV infection induces the expression of both classical and nonclassical MHC-I molecules on primary mouse brain astrocytes, mouse embryonic fibroblasts (MEFs) and H6 (hepatoma cell). The levels of adhesion molecules as well as molecules involved in antigen processing and presentation were also analyzed and our results clearly demonstrate that JEV infection induces their expression on astrocytes, MEFs and H6. The role of NF-κB and type-I IFNs in the induction of classical and nonclassical MHC-I molecules as well as molecules involved in antigen processing and presentation were also analyzed and our results demonstrated that type-I IFN mediated signaling is responsible for the induction of these molecules during JEV infection.
Chapter 1 discusses the innate and adaptive immune system, the role of classical and nonclassical MHC molecules in the initiation of immune response and diverse strategies adapted by different viruses to evade the immune response. It also includes a detailed discussion about the IFN and NF-κB signaling pathways and their modulation by viral infection. Finally, the genome organization, epidemiology, transmission cycle, pathogenesis and pathology, clinical features, humoral as well as cell mediated immune response to JEV infection and the current vaccine status to JEV infection are briefly discussed.
Chapter 2 describes the general materials and methods used in this study. It includes the details of the reagents and cell lines used in the experiments. It also discusses the various techniques such as RT-PCR, FACS analysis, EMSA and ELISA.
Chapter 3 focusses on the validation of different knockout MEFs used in the study as well as confirming the purity of primary astrocyte cultures established from pub brains. The susceptibility of various cells to JEV infection has also been investigated. Our results confirmed the authenticity of all the cells and the purity of primary astrocyte cultures used in the study. Our results also indicated that all the cells used in the study are susceptible to JEV infection.
Chapter 4 discusses the expression of MHC and related genes involved in immune response upon JEV infection of primary mouse brain astrocytes, MEFs and H6. Chapter 4 demonstrates for the first time that JEV infection induces the expression of nonclassical MHC-I or class Ib molecules namely Qa-1, Qb1 and T10 in addition to the induction of classical MHC-I molecules. In contrast to WNV, there was no increase in the cell surface expression of MHC-II molecules upon JEV infection of primary mouse brain astrocytes. JEV infection also induces the expression of adhesion molecules as well as molecules involved in antigen processing and presentation namely Tap1, Tap2, Tapasin, Lmp2, Lmp7 and Lmp10.
Chapter 5 demonstrates that JEV infection induces NF-κB activation in astrocytes and MEFs. Studies using MEFs deficient in classical and alternate pathways of NF-κB activation indicate that JEV activates the classical pathway of NF-κB activation and is dependent on canonical lKKβ/IKK2 activity. JEV infection of astrocytes, MEFs and H6 induces the production of type-I IFNs. To determine the mechanism of type-I IFN induction during JEV infection, MEFs deficient in NF-κB signaling and IFN signaling were used. Results indicate that type-I IFN production in MEFs occurs by both NF-κB dependent and independent mechanisms.
In contrast, the production of IFN-α was completely abrogated in IFNAR-\- MEFs whereas IFN-β production was greatly reduced. Production of type-I IFNs in IFNGR-\- MEFs is also reduced upon JEV infection but the reason for this is unclear.
Chapter 6 demonstrates that JEV induced expression of classical MHC-I molecules occurs by type-I IFN mediated signaling. This result is in contrast to WNV infection, in which both NF-κB and type-I IFNs are involved in the induction of classical MHC-I molecules. Type-I IFNs were also shown to be involved in the induction of nonclassical MHC molecules namely, Qa-1 and Qb1 during JEV infection. In contrast, the expression of T10, another nonclassical MHC molecule occurs independent of type-I IFN signaling. The expression of molecules involved in antigen processing and presentation namely, Tap1, Tap2, Lmp2 and Lmp7 was type-I IFN-mediated, whereas the expression of Tapasin and Lmp10 was mediated by both type-I IFN dependent and independent mechanisms. The expression of VCAM-1 was dependent on NF-κB mediated signaling.
Chapter 7 precisely describes the underlying mechanism of induction of MHC and various other related molecules and their significance during JEV infection. In addition, it also includes a working model for the induction of these molecules during JEV infection.
In summary, this is the first study in which the mechanism of JEV mediated induction of classical as well as nonclassical MHC molecules has been studied in detail. This study clearly demonstrated that type-I IFNs are involved in the induction of classical and nonclassical MHC-I molecules during JEV infection. The functional significance of this JEV mediated induction of classical MHC-I molecules is unclear, but it has been proposed that this is to escape from the action of NK cells. The absence of MHC-II induction during JEV infection could be important because it may lead to the initiation of an immune response which is different from that induced during other viral infections which induce the expression of MHC-II molecules. In contrast to classical MHC-I molecules, the functional and biological significance of nonclassical MHC-I molecules are poorly studied. Nonclassical MHC-I molecules play an important role in bridging adaptive and innate immune response. So the nonclassical MHC molecules induced during JEV infection may play an important role in the initiation of immune response during JEV infection. The role these nonclassical MHC-I molecules in antigen presentation during JEV infection is not known. These nonclassical antigens are also recognized by NK and γδT cells, thus the expression of nonclassical MHC-I molecules during JEV infection might also confer a protective role.
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Huang, Kuan-Hua, and 黃冠華. "Study of Alzheimer's disease model induced by Japanese encephalitis virus." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/50593724064153956373.
Full textAbstract:
碩士國立臺灣海洋大學
食品科學系
100
Japanese encephalitis virus (JEV), a neurotropic flavivirus, is one of the major causes of acute encephalitis in human. The mortality range between 5 to 60%. However, it often results in severe neurological sequelae and learning disabilities after rehabilitation. Alzheimer’s disease (AD), a progressive neurodengenerative disorder, is the most common form of dementia among the elderly. It causes mental deterioration, mobility, lack of sense of space and sense of direction and mood swings symptoms. Japanese encephalitis can cause degradation of intelligence and serious damage of the nervous system which is similar to Alzheimer’s disease. The aims of this study are to explore the pathologic correlation of the Japanese encephalitis virus and the Alzheimer’s disease, and to use the antioxidants EGCG (Epigallocatechin-3-gallate) and Vit. C (Vitamin C) to observe whether they can attenuate the inflammation caused by Japanese encephalitis virus. Animal experiments showed that mice infected with JEV, the expressions of APP (amyloid of precursor protein) and BACE (β-secretase), Alzheimer’s disease related factors, increased in a dose-dependent manner. In addition, the expression of TTR (transthyretin) decreased, so did iNOS and beta-amyloid (Aβ), some loosely structures were observed in the hippocampus and cortex. The memory and the learning ability of the mice infected with low-dose JEV decreased with time elapse, similar to 16 month old mice. And Aβ were observed in the hippocampus and cortex. However, antioxidant compounds EGCG and Vit. C increased the expressions of APP, BACE and iNOS; while the expression of TTR decreased in neuron cell. In summary, our results showed that JEV infection may result in the Alzheimer’s disease related genes expression and inteligence degradation similar to Alzheimer’s disease. The antioxidants EGCG and Vit. C can improve the expressions of APP, TTR, BACE and iNOS.
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Jen, Tai-Kuei, and 任泰癸. "Newcastle disease virus induced caspase-independent apoptosis pathway in BHK-21." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/56706509675087252494.
Full textAbstract:
碩士國立屏東科技大學
生物科技系所
104
The Newcastle disease virus (NDV), a negative single strand RNA virus, is an important domestic poultry and other bird species infectious pathogen of Newcastle Disease. It is a worldwide problem that presents primarily as an acute respiratory disease, but depression, nervous manifestations, or diarrhea may be the predominant clinical form. NDV may induces apoptosis in lymphoid tissue. Beside the pathology case reports, latest researchers also dedicated to developing a new kind of anti-cancer drugs based on the characteristics of Paramyxovirus. The apoptosis can be divided into two pathways, one is caspase dependent pathway and other is caspase independent pathway. The caspase dependent pathway was almost studied by other researchers before. However, a few studies based on caspase independent pathway and unclear. According to the cell viability analysis, we confirmed that BHK-21 cell showed the cell death after add NDV for 24 hours. Furthermore, we found that data of DNA fragmentation and TUNEL assay showed apoptosis of BHK-21 cell via dependent pathway after add NDV for 12 and 24 hours. However, the apoptosis still occurred as we used 100 μM caspase inhibitor z-VAD-fmk to inhibit the undergoing of caspase pathway. The DNA fragmentation is follow the treatment time addition DNA ladder become more. The DNA laddering present in untreated with inhibitor but not found in treated with z-VAD-fmk. The TUNEL assay, showed that the apoptosis and cell fusion both treatments, however in treatment with caspase inhibitor group is lower than untreated group. Finally, according the results of western blot assay and immunefluorescence staining, the apoptosis of BHK-21 cells induced by NDV were confirmed. The main of apoptosis pathway is mitochondria apoptosis pathway. When the cells apoptosis to undergoing associated with apoptosis proteins (Bax, Mst3, AIF, Endo G) in caspase independent pathway, however the apoptosis can be suppressed by using caspase inhibitor of z-VAD-fmk. Bcl-2 was decreased in the both treatments. The immunofluorescences staining and the western blot we check the AIF and Endo G translocation for mitochondria (cytoplasmic) to nuclear. On the expression of Actin, another apoptotic protein were decreased as the apoptotic response went more severe as a result of the reaction of caspase-associated proteases.
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Vaziry, Asaad. "Chicken infectious anemia virus vaccination induces immune disorders and viral persistency in infectious bursal disease virus-infected young chicks." Thèse, 2010. http://hdl.handle.net/1866/5101.
Full textAbstract:
La bursite infectieuse aviaire (IBD) est une des causes majeures de pertes économiques pour l’industrie aviaire. La vaccination est le principal outil de contrôle de cette maladie et les oiseaux susceptibles doivent être vaccinés aussitôt que le niveau des anticorps maternels (MA) anti-IBDV est suffisamment bas. L’estimation du moment de vaccination est habituellement déterminée par la formule de Deventer qui utilise le titre initial de MA anti-IBDV et la demi-vie des anticorps pour prédire l’évolution du titre. Dans la présente étude, l’effet du gain de poids sur la vitesse de disparition des MA a été étudié dans le but de l’utiliser pour prédire la détermination du moment de la vaccination. L’analyse des taux d’anticorps neutralisants par ELISA a montré que les poussins avec une forte croissance avaient un taux de disparition plus rapide des MA que ceux à faible croissance. Une formule pour la prédiction du moment de vaccination contre le IBDV, basée sur le gain de poids et le niveau des MA a été développée et vérifiée. La prédiction du moment de vaccination avec cette formule a montré une haute corrélation avec les titres de MA mesurés par ELISA.
Le virus de l’anémie infectieuse aviaire (CIAV) est une cause importante d’immunosuppression chez le poulet augmentant la pathogénicité des infections secondaires et en entraînant une réponse humorale suboptimale et une forte mortalité. D’autre part, l’infections sub-clinique du au CIAV provoque une immunosuppression qui facilite la coinfection par d’autre virus tel que le IBDV. Les effets de la coinfection à J1 avec une souche vaccinale de CIAV CAV-VAC® (Intervet) et à J14 avec une souche faiblement virulente de IBDV isolée au Québec, sur l’état de santé des poussins, sur la persistance virale et sur la réponse immunitaire ont été étudiés autant chez des poussins de 1 jour d’âge exempts d’agents pathogènes specifique (SPF) que ceux provenant d’élevages commerciaux. Les résultats ont montré que l’inoculation de la souche vaccinale du CIAV a entraîné une infection sub-clinique, une persistance virale dans la rate et le thymus, une altération de la thymopoièse et une réponse humorale temporaire chez les poussins SPF. Ces effets ont aussi été mis en évidence chez des poussins d’élevage commerciaux malgré des taux élevés de MA. Lors de l’infection avec la souche de IBDV chez des poussins déjà vaccinés contre le CIAV, la persistance du CIAV dans les organes lymphoïdes a été aggravée par une présence de réponses humorales temporaires contre les deux virus et une altération des populations lymphocytaires dans les organes lymphoïdes. Par contre, la présence des MA contre le CIAV a limité temporairement ces effets. Ces travaux ont mis en évidence des désordres immunitaires cellulaires et humoraux et une persistance virale chez des poussins vaccinés contre le CIAV et co-infectés avec le IBDV.Infectious bursal disease (IBD) is one of the major causes of economic losses in the chicken industry. Vaccination is the main tool against the disease, and the susceptible birds should be vaccinated as soon as the maternal antibody (MA) becomes low enough to allow the vaccine to break through. Estimation of vaccination time is currently performed by Deventer formula which uses initial anti-IBDV titer and antibody half-life to predict the titer. Considering the increased growth rate of chicken in the last decades and the wide variations of MA, we have examined the effects of chick’s weight gain on MA decline and the use of weight in predicting IBD vaccination time. The virus neutralization test and ELISA results demonstrated that fast-growing birds had a faster rate of antibody decline whereas slow-growing birds demonstrated a slower rate. Based on the effect of weight-gain on maternal antibody decline, a new formula for predicting IBD vaccination time was introduced and tested. The predicted IBD vaccination time made by this weight formula showed higher correlation with the measured ELISA titers in the experiment. Chicken infectious anemia virus (CIAV) is another cause of immunosuppression in chicken which is characterized by increased pathogenicity of secondary infectious agents, sub-optimal antibody responses and mortality. CIAV subclinical infections can result in immunosuppression and enhancement of pathogenicity of co-infecting agents such as infectious bursal disease virus (IBDV). Effects of pathogenic CIAV and IBDV coinfection on chick’s health and immune responses are investigated in different studies. In this study, newly hatched specific pathogen free (SPF) and commercial chicks were vaccinated with CAV-VAC® (Intervet) vaccine and /or inoculated with a low-virulent Québec isolate of IBDV at 14 days post CIAV vaccination. Inoculation of the CIAV vaccinal strain at hatch resulted in subclinical infection associated with viral persistency in spleen and thymus, alteration of thymopoiesis and transient humoral response in SPF chicks. Subclinical infection, viral persistency and lack of antibody responses were also shown in CIAV inoculated commercial chicks with high MA. Infection of the low-virulent IBDV in the CIAV vaccinated SPF chicks lead to extended viral persistence of CIAV in lymphoid organs, transient immune responses to both CIAV and IBDV, and alteration of lymphocytes subpopulation in the lymphoid organs. In the coinfected commercial chicks, presence the CIAV in the lymphoid organs was controlled by MA in the first 1-2 weeks after hatch. Thereafter, the immune disorders, viral persistence and lack of humoral responses almost similar to the coinfected SPF chicks were recorded.
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Dean, Dana Deanna. "Encapsulated interferon-tau during Theiler's virus-induced demyelinating disease: efficacy of treatment and immune response profile." Thesis, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3113.
Full textAbstract:
Multiple sclerosis (MS) is the most common primary demyelinating disease of the
central nervous system in humans. Type I interferons are most frequently used to treat MS.
However, their main mechanism of action remains elusive. Various biomarkers have been
investigated for their ability to assess treatment efficacy, but results are often confounding due to
differences in experimental design and variation in individual physiology. In fact, not all MS
patients respond to IFN therapy and a significant number suffer severe negative side effects and
must cease treatment. Thus, alternative therapeutics that offer less cytotoxicity and greater
efficacy are a major objective of research.
This dissertation evaluated a novel type I interferon, interferon-tau (IFNT), and its
ability to attenuate Theiler’s virus-induced-demyelinating disease (TVID), a mouse model of
MS. In this model, viral infection with the BeAn strain of Theiler’s murine encephalomyelitis
virus (TMEV) is the initiating factor leading to demyelination of the CNS. It was hypothesized
that IFNT would: 1) provide therapeutic benefit as witnessed by a stabilization of clinical score,
a decrease in CNS inflammation, and a decrease in CNS demyelination, and 2) shift the immune
profile from a Th1 to a Th2 response.
Once mice developed chronic disability, IFNT treatment began. This novel IFN was
delivered in an innovative way: encapsulation (eIFNT) in an alginate polymer, which allowed for
slow and sustained release. eIFNT was delivered by a 100 μl intraperitoneal injection (i.p.) containing 1.4M U of IFNT once every two weeks for 8 weeks. Mice were clinically scored
weekly and BeAn-eIFNT mice demonstrated a decrease in clinical score. Bright field
microscopy was used to evaluate CNS tissues where a decrease in demyelination and
inflammation was noted in BeAn-eIFNT-treated mice. Ex vivo stimulation of virus-specific
lymphocytes revealed an increase in both T helper 1 (Th1) and T helper 2 (Th2) cytokine
production. Specifically, TNFA was produced at very high levels by splenocytes from BeAneIFNT
mice in response to UV-inactivated BeAn alone and in the presence of IFNT when
compared to BeAn-eMOPS mice under the same conditions. IFNG was produced at elevated
levels from the splenocytes of BeAn-eIFNT mice versus BeAn-eMOPS mice when stimulated in
vitro with UV-inactivated Bean and with BeAn in the presence of IFNT. IL-2 was produced at
moderately elevated levels from the splenocytes of BeAn-eIFNT mice versus BeAn-eMOPS
mice when stimulated in vitro with UV-inactivated Bean. Il-2 was elevated to a statistically
significant level (p<0.05) from BeAn-eIFNT mouse splenocytes when stimulated with BeAn in
the presence of IFNT when compared to BeAn-eMOPS mice and IL-10 was produced at
elevated levels by splenocytes from BeAn-eIFNT mice versus that produced from BeAn-eMOPS
mouse splenocytes in response to UV-inactivated BeAn alone and in the presence of IFNT.
Quantification of T regulatory (Treg) cells in the spleen of eIFNT vs. eMOPS mice and blood of
eIFNT vs. eMOPS mice revealed no difference between the two groups. There was no statistical
difference in virus-specific serum antibodies at the pretreatment time point noted in the OD
readings of eIFNT mice at a dilution of 1/200 compared to the eMOPS mice. A modest decrease
in the OD values at the 1/200 dilution were noted in the eIFNT mice compared to the eMOPS
mice, but this difference was not significant. Antibody secreting cells (ASCs) from eIFNT mice
versus eMOPS mice were slightly lower in the spleen and brains whereas there was a slight increase in ASCs from the spinal cord of eIFNT mice when compared to those from eMOPS
mice.
Altogether, the results support efficacy of the eIFNT treatment in the mice with TVID.
Actual mechanisms of disease attenuation remain elusive at this time as mice exhibited an
increase in certain Th1 and Th2 cytokines rather than the hypothesized shift from a Th1 to a Th2
immune profile. Likewise, mice exhibited a modest decrease in virus specific antibodies as well
as the number virus-specific ASCs which also refute the hypothesized increase in these values. A
remarkable finding was the fact that immune cells derived from eIFNT treated mice appeared to
be divided into two distinct types of biological responders although all of the mice responded to
the in vivo treatment with a decrease in disease severity. It is hypothesized that this difference is
a reflection of individual genetic variability in response to immune modulation which is
surprising owing to the fact that the animals used for these studies are in-bred and considered to
be as identical genetically as is feasible in a population of animals. Obviously, immune
modulation can proceed through different mechanisms and still provide the desired result of a
decrease in disease severity. However, this reality creates an added level of difficulty when one
is trying to interpret biological data in order to determine whether a therapeutic regimen is
efficacious within a patient population.
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Khidr, Yehia [Verfasser]. "Development of a strategy to induce RNA-silencing in squash against virus diseases by genetic transformation / presented by Yehia Khidr." 2007. http://d-nb.info/98470583X/34.
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Takalani, Tanganedzani. "Adherence: Perceptions and behaviour of patients on Antiretroviral in Vhembe District of Limpopo Province, South Africa." Diss., 2019. http://hdl.handle.net/11602/1496.
Full textAbstract:
MA (Psychology)Department of Psychology
Background: An estimated 70% of people in Sub-Saharan Africa out of 25 million are living with HIV. HIV is a debilitating disease, however, antiretroviral treatment helps promote effective viral suppression, reduces the risk of transmission and prevents death (WHO, 2013). To ensure positive treatment outcomes, high levels of Anti-Retroviral Therapy (ART) adherence, 95%, is necessary, however, research indicates that 23% of Africans are achieving less than 80% adherence, potentially impacting negatively on prognosis. Aim: The aim of this study was to determine adherence, explore perceptions and behaviour of patients on Antiretroviral Therapy attending Thohoyandou Health Centre, in Vhembe District, Limpopo, South Africa. Methodology: This was a mixed method which employed both quantitative and qualitative research approaches. In quantitative, triangulation was utilised through a questionnaire and patients’ file, simple random sampling was used to select 105 male and female patients aged 18-60 who are on ART at Thohoyandou Health Centre; data were collected and SPSSversion 25 was used to analyse the data through descriptive, cross tabulation and inferential statistics using Chi-square.Qualitative phase – phenomelogical research design was utilised, twenty participants were purposively sampled and individually interviewed, ATLAS. ti program was used to analyse the data collected. Results: 67% of respondents were females, 34% of the respondents’ age range was 50-60 years, 44.8% were single, 48.6% had tertiary education and 69.5% were unemployed. The self-report of ART adherence of 87.6% among patients was indicated, with 19.6% who reported defaulting ART, 14.3% admitted to missing medical appointments. The reasons for missing medical appointments were: forgetfulness, not a convenient time, patient feeling better, transportation challenges and being too sick to attend. The objective evaluation of patients’ CD4 count at baseline revealed that 40.9% of patients had a CD4 count of <200c/mm3, out of 40.9% respondents (15.2%) were those aged between 41-50 years, 31.4% of respondents did not know their CD4 count for various reasons (defaulted on treatment, missed appointments). CD4 count follow-up data after six months revealed that 33% of patients had a CD4 count <200c/mm3 and 39% accounted for unknown CD4 count. vi Three themes emerged from the data, namely: Knowledge of HIV were respondents presented a negaitive and positive perception of ths diagnosis; barriers to ART adherence where sub-themes included discrimination, strigma, rejection, inadequate knowledge about the diagnosis and treatment, side effects; coping strategies where acceptance, religion and social support serve as corner stones for patients. Association was examined and findings did not reveal any significant association between gender, marital status, education, occupation; however, age was significantly associated with non-adherence to ART with X2 = 3.69, df = 1, p = < .002. Recommendations: The study recommends intensification of health education campaign against stigma, discrimination, rejection and other barriers to enhance positive attitude towards HIV patients that wil consequently stimulate adherence and alleviate the burden associated with taking treatment unswervingly. Given the high percentage of infected older respondents, government must also focus its resources to educate illiterate and older people about HIV, adherence and management in order to achieve the golden standardrate of 95% adherence. Strategies to facilitate and normalise adherence among males is indicated.
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Manenzhe, Tovhowani. "Adherence of antiretroviral therapy and mental health of HIV-diagnosed patients in Vhembe District, Limpopo Province." Diss., 2019. http://hdl.handle.net/11602/1501.
Full textAbstract:
MA (Psychology)Department of Psychology
Background: Given that there is 57.7 million HIV-diagnosed people living in South Africa and the government has established the largest public antiretroviral programme in the whole world but only 53% are adhering. Adherence remains a challenge, due to presence of mental health issues among HIV diagnosed. Aim: The aim of this study was to investigate adherence to antiretroviral therapy and mental health of HIV-diagnosed patients in Vhembe District, Limpopo Province. Methods: This was a mixed method study using a combination of quantitative and qualitative research approaches. In the quantitative approach, triangulation was utilised in the form of a questionnaire and patients records. Simple random sampling was used to select 134, descriptive analysis using SPSS version 25. For the qualitative approach, a phenomenological research designs was considered and convenience sampling was used to select fifteen participants (15). Data was collected using semi-structured interview; responses were analysed using a computer-aided program called, ATLAS ti. Results: The self-report of adherence was 94.8 %, objectively 39.6% of CD4 count <200c/mm3 at baseline and 34.3% CD4 count after six months was found. 16.5% of females and 2% of males defaulted treatment and 14.9% of missed medical appointments 1-6 times. This study also revealed the mental health issues that HIV-diagnosed patients are struggling with after the diagnosis include the stages of grief, stress, depression, anxiety, mistrust, shame, stigma and discrimination. Recommendation: Effective strategies need to be enhanced and tailor made in effort to encourage patients to take ART diligently. The healthcare providers, community members and the government should be made aware of mental health issues.
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