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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Hantavirus transmission risk in function of climate and landscape structure / O risco de transmissão da Hantavirose em função do clima e da estrutura da paisagem

Prist, Paula Ribeiro 14 December 2016 (has links)
Hantavirus Cardiopulmonary Syndrome (HCPS) is a disease caused by Hantavirus, which are negative-sense RNA viruses in the family Bunyaviridae. These viruses are highly virulent to humans, taking about 50% of infected people to death. The main Hantavirus reservoir is constituded by generalist rodents species, which increase in abundance in agricultural and fragmented landscapes, potencially augmenting the transmission risk of the disease. Climate can also affect rodent population dynamics and the virus survival in the environment, as well as the time it remains virulent, while social factors may regulate the processes of transmitting viruses from reservoirs to humans. However, despite the high virulence of these viruses and the lack of vaccine is not yet well established how these different factors linked to landscape structure, climate and social conditions affect the dynamics of transmission of the disease. Thus, this study aimed to: 1) identify which social and ecological factors affect the transmission of HCPS, identifying the areas of greatest risk in the state of São Paulo and 2) predict how climate change (RCP4.5 and RCP8.5) and expansion of sugarcane scenarios influence the transmission of HCPS. To answer these questions the study system corresponded to the 645 municipalities that compose the state of São Paulo. To achieve our goals, in a first chapter, we conducted a literature review to understand how landscape structure and climate variables affect the risk of HCPS. In a second chapter we used a Bayesian model to quantify the association between HCPS annual incidence in the state of São Paulo, obtained by the number of cases confirmed by the Ministry of Health, between the years 1993-2012, and climate variables (total annual precipitation and mean annual temperature), landscape structure (percentage of native vegetation, number of fragments and percentage of area occupied with sugarcane), chosen in the literature review, and social factors (number of rural men over 14 years - risk population, and the Human Development Index - HDI). We build separate models for the Atlantic Forest and the Cerrado. In both biomes, the risk of HCPS increased mainly with the proportion of land cultivated with sugarcane and the HDI, but the proportion of native habitat, mean annual temperatures and risk population also showed positive relationships to Atlantic Forest. The average risk of HCPS for the state of São Paulo was 1.3%, with 6% of the municipalities being classified as medium to high risk (>= 5%). In a third chapter we used sugarcane expansion and extracted temperature anomalies of RCP4.5 and RCP8.5 scenarios of general circulation models (GCMs) of IPCC5 to predict HCPS risk. With sugarcane expansion, average risk for HCPS increases from 1.3 to 1.5%, while RCP4.5 and RCP8.5 scenarios increased the risk to 1.6% and 1.7%, respectively. RCP4.5 and RCP8.5 scenarios alone are responsible for the largest increase in the maximum risk of infection (46.1% to 51.4% and 51.7%), while the sugarcane expansion combined with climate scenarios are causing the larger expansion in the number of municipalities at high risk, which goes to 7%. Our analyzes provide the first evidence on the action of landscape, climate and social factors in HCPS incidence in the Neotropics. Moreover, our risk maps can be used to optimize the correct allocation of resources, allowing actions to be taken to reduce the impacts of sugarcane expansion and climate change over this disease propagation / A Síndrome Cardiopulmonar por Hantavirose (HCPS) é uma doença causada por Hantavírus, um conjunto de vírus com RNA negativo pertencentes à família Bunyaviridae. Esses vírus são altamente virulentos para os seres humanos, levando cerca de 50% dos infectados a óbito. O principal reservatório de HCPS é constituído por espécies de roedores generalistas, que aumentam em abundância em paisagens agrícolas e fragmentadas, potencialmente elevando o risco de transmissão dessa doença. O clima também pode afetar a dinâmica populacional dos roedores e a sobrevivência do vírus no ambiente, assim como o tempo em que este se mantém virulento, enquanto que fatores sociais podem regular os processos de transmissão dos vírus dos reservatórios para os seres humanos. No entanto, apesar da alta virulência destes vírus e da falta de vacina, não está ainda bem estabelecido como esses diferentes fatores ligados à estrutura da paisagem, ao clima e às condições sociais afetam a dinâmica de transmissão dessa doença. O presente trabalho teve assim como objetivos: 1) identificar quais fatores ecológicos e sociais afetam a transmissão de HCPS, identificando as áreas de maior risco no estado de São Paulo e 2) prever como cenários de mudanças climáticas (RCP4.5 e RCP8.5) e de expansão de cana-de-açúcar influenciam a transmissão de HCPS. Para responder aos nossos objetivos, o sistema de estudo compreendeu os 645 municípios que compõe o estado de São Paulo. Num primeiro capítulo, realizamos uma revisão bibliográfica para entender como as variáveis de paisagem e de clima afetam o risco de HCPS. Num segundo capítulo, utilizamos um modelo Bayesiano para quantificar a associação entre a incidência anual de HCPS no estado de São Paulo, obtida através do número de casos confirmados pelo Ministério da Saúde, entre os anos de 1993 a 2012, e as variáveis de clima (precipitação total anual e temperatura anual média), estrutura da paisagem (porcentagem de vegetação nativa, número de fragmentos e porcentagem de área ocupada com cana-de-açúcar), escolhidas na revisão bibliográfica, além de fatores sociais (número de homens rurais acima de 14 anos - população de risco, e o Índice de Desenvolvimento Humano - IDH). Construimos modelos separados para a Mata Atlântica e o Cerrado. Em ambos os biomas, o risco de HCPS aumentou principalmente com a proporção de terra cultivada com cana-de-açúcar e com o IDH, mas a proporção de habitat nativo, temperatura anual média e população de risco também mostraram relações positivas para Mata Atlântica. O risco médio de HCPS para o estado de São Paulo foi de 1.3%, com 6% dos municípios sendo classificados como de médio a alto risco (>= 5%). Num terceiro capítulo, utilizamos cenários de expansão de cana-de-açúcar e anomalias de temperatura extraidas dos cenários RCP4.5 e RCP8.5 de 32 modelos de circulação geral (GCMs) do IPCC5 para prever os riscos futuros de HCPS. Com a expansão de cana-de-açúcar, o risco médio de HCPS para o estado aumenta de 1.3 para 1.5%, enquanto que os cenários RCP4.5 e RCP8.5 aumentam o risco para 1.6% e 1.7%, respectivamente. RCP4.5 e RCP8.5 sozinhos são os cenários que mais aumentam o risco máximo de infecção (46.1% para 51.4% e 51.7%), enquanto que a expansão de cana-de-açúcar combinada com os cenários climáticos são os que mais provocam o aumento da expansão do risco no estado de São Paulo, expandindo o número de municípios em alto risco para 7%. Nossas análises fornecem as primeiras evidências sobre a ação de fatores da paisagem, climáticos e sociais na incidência de HCPS nos Neotrópicos. Também, nossos mapas de risco podem ser utilizados para otimizar a correta alocação de recursos, permitindo que ações sejam tomadas para reduzir os impactos da expansão da cana e das mudanças climáticas sobre a propagação da doença
72

Géographie de zoonoses en Thaïlande : de la distribution des rongeurs, vecteurs et hôtes, au risque de transmission

Herbreteau, Vincent 10 December 2007 (has links) (PDF)
Longtemps considérés en Thaïlande comme simple gibier mais souvent destructeurs des cultures, les rats et les souris (Murinae) se sont révélés d'importants vecteurs de germes pathogènes pour l'Homme, depuis l'émergence soudaine de la leptospirose en 1996. Ils sont aussi responsables de la transmission du typhus des broussailles et probablement d'hantaviroses dont l'incidence reste suspectée. Cette thèse a pour objectif d'analyser la géographie de ces zoonoses afin d'en mesurer le risque de transmission à l'Homme.<br />Un important travail de terrain a permis de collecter et d'étudier les rongeurs murins dans différents milieux représentatifs de leur diversité. Parallèlement, une enquête conduite dans la province de Phrae a montré la variabilité du système de soins et des comportements de santé. Un Système d'Information Géographique « Rongeurs et santé » centralise l'intégralité des données sur l'ensemble du territoire pour une analyse spatio-temporelle.<br />Cette recherche a permis de mettre à jour la description et la distribution par télédétection des principaux rongeurs murins thaïlandais ainsi que leur implication dans la transmission de germes pathogènes. La géographie de ces zoonoses reflète des différences de niveau de vie : l'exposition de l'Homme à ces maladies résulte de la chasse et de la consommation de rongeurs mais aussi d'un accès et d'un recours aux soins limités, traduisant ainsi la pauvreté des populations touchées.<br />Ce travail offre une approche critique des méthodes alliant les outils de la géomatique, l'analyse spatiale et la télédétection, pour l'étude des zoonoses.
73

Implications of Local Puumala Hantavirus Genetics and Epidemiology for Diagnostics and Vaccine Development

Johansson, Patrik January 2005 (has links)
Puumala viruses, a member of the Hantavirus genus in the Bunyaviridae family, are enveloped by a lipid bilayer and possesses a tripartite single stranded RNA genome with negative polarity. The hantaviruses encode four proteins: a nucleocapsid protein (N), two membrane spanning glycoproteins (GN and GC) and a RNA dependent RNA polymerase (RdRp). Hantaviruses cause two forms of diseases, hemorrhagic fever with renal syndrome (HFRS) in Europe and Asia, and hantavirus pulmonary syndrome (HPS) in the Americas. The hantaviruses are mainly rodent borne, and humans are mostly infected by inhalation of aerosolized rodent secrete. Human Puumala virus infection results in nephropathia epidemica (NE), a mild haemorrhagic disease. It is of importance to have a good understanding of the epidemiology and genetics of these viruses for the development of new diagnostic methods and for future vaccine development. In this thesis we determined the complete viral genome sequence and characterized the structural proteins based on studies of expression and glycosylation patterns, for a unique human virus isolate; performed a genomic analysis of local Puumala viruses and their individual rodent host, Clethrionomys glareolus, from six different locations was performed. It was seen that the virus genetic variation between different locations could be stable over relatively large distances while there could be large variation over a short distance. For the bank voles no such variation could be seen; developed and evaluated Genetic vaccines, based on PCR-generated linear DNA. We showed that it was important to protect these fragments against nuclease degradation at that attachment of a nuclear localization signal peptide further improved the immune response. We also designed, fabricated and evaluated a 2000 probe cDNA-microarray for identification and differentiation of hantaviruses. The chips was based on 12 different strains of six hantaviruses and could differentiate between both different hantaviruses and strains within one hantavirus serotype.
74

TRANSMISSION AND PATHOGENESIS OF HANTAVIRUS / HANTAVIRUS ÖVERFÖRING OCH PATOGENES

Pettersson, Lisa January 2015 (has links)
Hantaviruses are the causative agents of hemorrhagic fever with renal syndrome (HFRS) in Eurasia, and of hantavirus cardiopulmonary syndrome (HCPS) in the Americas. Transmission to humans usually occurs by inhalation of aerosolized virus-contaminated rodent excreta. To date, human-to-human transmission has only been described for the Andes hantavirus. The mode of transmission of Andes hantavirus is not yet known, but transmission through saliva has been suggested. In Sweden, we have one hantavirus that is pathogenic to humans, Puumala virus (PUUV), which is endemic in Central and Northern Europe. It induces a relatively mild form of HFRS, also called nephropathia epidemica (NE). The rodent reservoir is the bank vole (Myodes glareolus). The mechanism behind the pathogenesis of hantavirus is complex and probably involves both virus-mediated and host-mediated mechanisms. The aim of this project was to investigate the transmission mechanisms and pathogenesis of hantavirus disease in humans. In our first study, we described the largest outbreak of PUUV so far in Sweden. We investigated factors that might be important for causing the outbreak, and suggested that a peak in the bank vole population together with concurrent extreme weather conditions most probably contributed to the outbreak. Our next studies concentrated on human-to-human transmission of hantaviruses. We found PUUV RNA in saliva from PUUV-infected patients, suggesting that there is PUUV in the saliva of infected humans, although no person-to person transmission appears to occur with PUUV.  In the studies that followed, we showed that human saliva and human salivary components could inhibit hantavirus replication. We also found PUUV-specific IgA in the saliva of PUUV-infected patients, which might prevent person-to-person transmission of the virus.  In the final study, we focused on the pathogenesis of NE. One hundred five patients were included in a prospective study.  They were divided into a group with mild disease and a group with moderate or severe disease. We found that the immune response had a dual role in disease development. It was partly responsible for development of severe disease, with significantly higher amounts of neutrophils in severely ill patients, but it was also protective against severe disease, because patients with mild disease had higher levels of PUUV-specific IgG. In conclusion, a peak in the bank vole population in combination with extreme weather will increase the risk of human infection, PUUV RNA is present in saliva, PUUV-specific IgA and salivary components inhibit person-to-person transmission of PUUV, and the immune response is important for the pathogenesis of PUUV and the severity of the disease. / Hantavirus är en grupp av virus som finns hos gnagare som bär på viruset utan att själva bli märkbart sjuka. Varje hantavirus har anpassat sig till sin egen art av gnagare som de infekterar (kallas virusets reservoar). Hantaviruset kan överföras till människor från gnagare och kallas då för en zoonos eftersom detsprids från djur till människa. I människa orsakar hantavirus blödarfeber med njurpåverkan i Eurasien och blödarfeber med med hjärt och lungpåverkan i Nord- och Sydamerika. I Sverige har vi bara ett hantavirus som är sjukdomsframkallande hos människor, Puumala-viruset som även finns i delar av övriga Europa. Det framkallar en relativt mild form av blödarfeber, som kallas sorkfeber eller Nephropathia epidemica. Puumala-virusets reservoar är skogssorken (Myodes glareolus). Människor smittas oftast av hantavirus när de andas in infekterat damm som innehåller utsöndringar (avföring, urin eller saliv) från gnagare som har torkat in och sedan blivit luftburet. Vad man vet hittills så finns det bara ett hantavirus som smittar från person till person, för övriga hantavirus är människan en ”dead end”. Det virus som kan smitta från person till person heter Andes hantavirus och finns i Sydamerika. Andes hantavirus har en mus som reservoar från vilken människor kan smittas, sedan har smittan i vissa fall förts vidare från människa till människa, som tur är har dessa utbrott gått att stoppa. Fastän utbrotten har varit små har många personer dött, eftersom dödligheten är så hög, ungefär 30-40% av de diagnostiserade fallen dör. Hur Andes hantavirus överförs från människa till människa är inte känt men överföring genom saliv har föreslagits. Hur viruset ger upphov till sjukdom hos människa är inte klarlagt. Studier talar för att mekanismen bakom sjukdomsutvecklingen (den så kallade patogenesen) hos hantavirusorsakade blödarfebrar är komplex. Sannolikt beror patogenesen både på egenskaper hos viruset och värden d.v.s. människan som är smittad av viruset. Vårt mål med detta projekt var att undersöka vad som hindrar överföring av Puumala hantavirus från människa till människa och att undersöka hur virusinfektionen påverkar sjukdomsutvecklingen hos människan. I vår första studie beskrev vi det största utbrottet av sorkfeber hittills i Sverige och vi undersökte faktorer som kan ha orsakat utbrottet. Vi föreslog att en topp i skogssorkpopulationen samtidigt med extremt varmt väder troligen bidrog till utbrottet. Utbrottet skedde i december och det extremt varma vädret medförde att snön smälte bort. Sorkarna bor vanligtvis under snön på vintern, vi tror att frånvaro av snötäcke fick sorkarna att söka sig till byggnader för att söka skydd och där kom i kontakt med människor. Våra efterföljande studier fokuserade på överföring av hantavirus från människa till människa. Vi hittade Puumala-virusets arvsmassa (RNA) i saliv från sorkfeberpatienter, vilket tyder på att det finns Puumala-virus i saliven hos infekterade människor, även om ingen överföring från person till person verkar inträffa. I efterföljande studier visade vi att mänsklig saliv och mänskliga salivkomponenter minskar hantavirus smittsamhet. Vi fann också Puumala-virusspecifika IgA-antikroppar i saliven från sorkfeberpatienter, vilket kan förhindra överföring från person till person. I den sista studien fokuserade vi på patogenesen hos människor efter hantavirusinfektion. 105 patienter ingick i en prospektiv studie och delades in i en grupp med mild sjukdom och en grupp med måttlig/svår sjukdom. Vi hittade en dubbel roll hos immunsvaret för sjukdomsutvecklingen. Immunsvaret var delvis ansvarig för utveckling av svår sjukdom med betydligt högre mängd neutrofiler hos svårt sjuka patienter, men det var också skyddande mot allvarlig sjukdom, eftersom patienter med en mild sjukdom hade högre nivåer av Puumalavirusspecifika IgG-antikroppar. Detta talar för att behandling med IgG-antikroppar specifikt riktade mot hantavirus skulle kunna vara effektiv hos hantavirusinfekterade patienter. Sammanfattningsvis; en topp i skogssorkspopulationen i kombination med extremt väder ökar risken för infektion hos människor; Puumala-virus arvsmassa (RNA) finns i saliv; Puumala-virusspecifika IgA-antikroppar och salivkomponenter hämmar överföring av Puumalavirus från person till person; immunsvaret är viktigt för Puumala-virus patogenes och sjukdomens svårighetsgrad.
75

Efecto de las proteínas de virus Andes (Hantaviridae) sobre la apoptosis mediada por TRAIL

Segovia Pavez, Raúl Emilio. 03 1900 (has links)
título de Ingeniería en Biotecnología Molecular / El virus Andes (ANDV) pertenece al género Orthohantavirus (familia Hantaviridae, orden Bunyavirales). En humanos la infección por ANDV produce el síndrome pulmonar asociado a hantavirus, el cual presenta una tasa de mortalidad de alrededor de un 35%. Estos virus se caracterizan por poseer una envoltura lipídica y un genoma de ARN de hebra simple tri-segmentado, de polaridad negativa que codifica para al menos 4 proteínas, entre ellas la proteína de nucleocápside (N) multifuncional y un precursor proteico denominado GPC, que tras ser procesado resulta en las glicoproteínas Gn y Gc que se encuentran ancladas en la envoltura viral. La apoptosis es una respuesta celular común frente a una infección viral. Sin embargo, en el ciclo replicativo de los hantavirus aún es controversial si inducen o inhiben apoptosis. La apoptosis celular puede ser inducida extrínsecamente mediante receptores de muerte específicos, que pueden ser activados por un ligando de la familia del factor de necrosis tumoral, como TRAIL (ligando inductor de apoptosis relacionado al factor de necrosis tumoral, por sus siglas en inglés) a través de una cascada de señalización, mediante un dominio de muerte. En este seminario de título, se buscó determinar si la expresión o localización del receptor de TRAIL, específicamente DR5 (receptor de muerte 5, por sus siglas en inglés) se ve alterada por la expresión de proteínas Gn, Gc y N de ANDV en células humanas, y si una posible variación podría afectar la tasa de apoptosis mediada por TRAIL. En primer lugar, se analizó la expresión de DR5 en distintos tipos celulares, y se determinó que éste receptor se expresa en mayor medida en células A549, por lo que para el resto de los análisis se continuó con esta línea celular. A continuación, se midió la expresión, tanto a nivel transcripcional como traduccional de DR5 en dependencia de ANDV Gn, Gc y N, frente a lo cual, no hubo una variación significativa en la expresión general de este receptor; sin embargo, en donde sí se encontró un incremento significativo fue en la localización de DR5 en la superficie de las células A549 en presencia de ANDV N. De todas formas, no se logró detectar inducción de apoptosis en células humanas transfectadas con ANDV N, lo cual no es posible interpretar debido a la carencia de un control positivo de apoptosis celular. En resumen, estos datos en conjunto muestran que a pesar de que la expresión de ANDV N indujo un aumento en la localización de DR5 en la superficie de células A549, sin embargo, queda por determinar si este aumento podría inducir apoptosis mediada por TRAIL. / Andes virus (ANDV) belongs to the Orthohantavirus genus (Hantaviridae family, Bunyavirales order). In humans ANDV infection causes hantavirus pulmonary syndrome, which has a fatality rate around 35%. These viruses are featured by a lipid envelope and a tri-segmented, single stranded, negative sense RNA genome, that encodes at least four proteins, among them, the multifunctional nucleocapsid protein (N) and a glycoprotein precursor termed GPC, which after being proteolytically cleaved, results in the mature glycoproteins Gn and Gc, which are anchored to the viral envelope. Apoptosis is a common cellular response against a viral infection. However, in the hantavirus replicative cycle, there is still controversy whether these viruses induce or rather block apoptosis. Apoptosis can be triggered extrinsically, through specific death receptors, that can be activated by a ligand belonging to the tumor necrosis factor family, such as TRAIL (tumor necrosis factor–related apoptosis inducing ligand), through a death domain mediated signaling cascade. During this degree seminary, we aimed to determine whether the expression or location of the TRAIL receptor DR5 (death receptor 5), is altered by ANDV Gc, Gn and N expression in human cells, and if any possible variation could affect TRAIL mediated apoptosis. First, we analyzed DR5 expression in different cell types and found that there is a higher extent of DR5 expression in A549 cells, that is why, for the rest of this seminary, we continued the work with this cell line. Next, we measured DR5 expression in these cells at a transcriptional and translational level, after being transfected with plasmids encoding ANDV Gc, Gn or N. We did not find any significant variation in the total amount of DR5 expression; nevertheless, we detected a significant increase in the location of DR5 on the surface of A549 cells in the presence of ANDV N. Although, we were unable to detect apoptosis in human cells transfected with ANDV N due to the lack of a positive control of apoptosis. Finally, all together, our results show that the expression of ANDV N induces an increase in DR5 on the surface of A549 cells, however, it has yet to be determined whether or not, this is enough to induce apoptosis mediated by TRAIL.
76

Role of Virus-Specific CD8+ T Cells in the Severity of Hantavirus Pulmonary Syndrome: A Dissertation

Kilpatrick, Elizabeth D. 05 January 2004 (has links)
The focus of this dissertation is the role of specific CD8+ T cells in the pathogenesis of a highly lethal human viral disease, hantavirus pulmonary syndrome (HPS). HPS is a zoonotic disease caused by transmission of Sin Nombre virus (SNV) from chronically infected deer mice. In humans, this fulminant infection is characterized by lung capillary leakage, respiratory failure and cardiogenic shock. Individuals with HLA-B*3501 have an increased risk of developing severe HPS, and the majority of defined CD8+ T cell epitopes in SNV are presented by this HLA allele, suggesting that CD8+ T cell responses to SNV contribute to pathogenesis. We speculate that CD8+ T cell mediated immune responses to SNV antigens in pulmonary endothelial cells contribute to the pathology of HPS. Specifically, we hypothesize that there are quantitative and/or qualitative differences in SNV-specific CD8+ T cell responses in HPS patients with moderate vs. severe disease. In this dissertation I measured the frequencies of SNV-specific CD8+ T cells during acute HPS. Using HLA/peptide tetramers, I quantitated circulating SNV-specific CD8+ T cells of all the available HLA-B35+ patients with HPS caused by SNV. This is the first time hantavirus-specific T cells have been quantitated during acute infection. I report that between 2.9% and 44.2% of the CD8+ T cells were specific for the three SNV epitopes in combination during acute disease in the patients analyzed in this study. These levels are very high in comparison to the frequencies reported in the literature for other acute human viral infections. Furthermore, I report significantly higher frequencies of SNV-specific T cells in patients with severe HPS requiring mechanical ventilation (up to 44.2% of CD8+ T cells) than in moderately ill HPS patients hospitalized but not requiring mechanical ventilation (up to 9.8% of CD8+ T cells). These results imply that virus-specific CD8+ T cells contribute to HPS disease outcome. In this dissertation I also provide preliminary data on qualitative aspects of SNV-specific T cells. Analysis of the TCR repertoire of SNV-specific T cell lines isolated from the PBMC of acute HPS patients raises the possibility that SNV-specific T cells express a limited number of TCR Vβ alleles; however, this is quite speculative because it is based on the analysis of only seven CTL lines. Analysis of cytokine expression by the CTL lines in response to in vitro antigen-specific stimulation indicate that SNV-specific T cells are capable of secreting IFN-γ, TNF-α, and IL-13 upon stimulation. The data presented in this dissertation extend previous studies, which suggested a role for virus-specific T cells in HPS pathogenesis and support our hypothesis that virus-specific CD8+ T cells contribute to HPS disease outcome. The results of this study will be useful in the design of future therapeutic strategies for this emerging human pathogen. The conclusions of this study may also benefit the study of other human viral hemorrhagic fevers. Improved understanding of the mechanism of pathogenesis of severe viral zoonoses will result in better treatment and prevention strategies.
77

Immunogenicity of hantavirus Dobrava nucleocapsid protein derivatives in mice

Geldmacher, Astrid 14 December 2005 (has links)
Das in Europa vorkommende Dobravavirus (DOBV) gehört zu den Hantaviren und wird durch die Gelbhalsmaus Apodemus flavicollis übertragen und kann im Menschen zu einem "Hämorrhagischen Fieber mit renalem Syndrom" (HFRS) führen. Das Nukleokapsidprotein (N) von Hantaviren ist stark immunogen in Menschen und eine Impfung mit rekombinanten N Derivativen wie chimaere Hepatitis B Virus (HBV) Corepartikel oder das komplette N schützt in Nagetiermodellen vor einer Hantavirusinfektion. In der vorliegenden Arbeit wurde die Immunogenität von zwei auf dem DOBV N basierende Protein Derivativen in Mäusen getestet. Es wurden in E. coli exprimierte chimaere HBV Corepartikel verwendet, die einen Teil des DOBV N trugen (HBcdDOB120), sowie in Hefen eprimiertes komplettes DOBV rN. Anschließend wurden BALB/c und C57BL/6 Mäuse mit den jeweiligen Proteinen immunisiert. Sowohl BALB/c, als auch C57BL/6 Mäuse entwickelten eine starke, langanhaltende N-spezifische Antikörperantwort, die eine starke Kreuzreaktivität gegenüber der rN anderer Hantaviren aufwiesen, nach Impfung mit HBcdDOB120 oder DOBV rN-Protein. Es wurden Antikörper aller IgG Subklassen, sowie N-spezifische IFN-( und IL-4 sekretierende Lymphozyten induziert, was auf eine gemischte Th1/Th2 Antwort schließen lies. Die Frequenz der durch die Immunisierungen induzierte N-spezifischen Lymphozyten war allerdings gering. Auch in Mäusen, die hohe HBc-spezifische Antikörpertiter aufwiesen konnte eine starke N-spezifische Antikörperantwort mittels Impfung mit HBcdDOB120 induziert werden. HBcdDOB120 und DOBV rN stellen vielversprechende Vakzinekandidaten dar, die auf ihre Protektivität hin getestet werden sollten. Da HBcdDOB120 sowie DOBV rN eine starke Antikörperantwort und nur eine schwache T-Zellantwort induzieren sollte zusätzlich die Rolle von N-spezifischen Antikörpern im Schutz gegen die Virusinfektion weiter charakterisiert werden. / In Europe, the hantavirus Dobrava (DOBV) is carried by the yellow-necked mouse Apodemus flavicollis and causes "haemorrhagic fever with renal syndrome" in humans. The nucleocapsid protein (N) is very immunogenic in infections of humans and rodents. Immunisation with N protein derivatives, like chimeric hepatitis B virus core (HBc) particles and entire recombinant N could protect rodents from a hantavirus infection. In this study, the immunogenicity of the two following derivatives based on the DOBV N protein was tested in mice. Chimeric HBV core particles, consisting of truncated HBc (HBcd) particles carrying part of the DOBV N (HBcdDOB120) were expressed in E. coli and the entire DOBV rN in yeast. Hence BALB/c and C57BL/6 mice were immunised subcoutanously with both antigens. Mice of both strains elicited strong and longlived N-specific antibody responses after HBcdDOB120 as well as after DOBV rN immunisation. Both derivatives induced antibodies that were highly cross-reactive to the rN of the hantaviruses Puumala, Hantaan, Andes and Sin Nombre. HBcdDOB120 and DOBV rN induced N-specific antibodies of all IgG subclasses, suggesting a mixed Th1/Th2 immune response. In the same line, IFN-( and IL-4 was secreted by N-specific lymphocytes from mice immunised with HBcdDOB120 or DOBV rN after in vitro restimulation which also indicated a mixed Th1/Th2 response. However, the frequency of N-specific lymphocytes was low. In mice that exhibited a high HBc-specific antibody titer HBcdDOB120 also induced a strong N-specific immune response. HBcdDOB120 and DOBV rN represent promising vaccine candidates that should be tested for their protective potential in a DOBV challenge model as soon as one gets available. Additionally, as protection might be partially based on N-specific antibodies, their role in protecting against a hantavirus infection should be characterised further.
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Ocorrência de anticorpos anti-hantavírus (IgG) em populações humanas na região Amazônica e no estado de São Paulo (Mata Atlântica), utilizando proteína recombinante (nucleocapsídio) do vírus Araraquara. / Detection of antibodies (IgG) against hantavirus in human population of Amazon region and the state of Sao Paulo (Atlantic Forest), using recombinant antigen of Araraquara virus.

Morais, Felipe Alves 11 November 2010 (has links)
A hantavirose (infecção por Hantavírus) é uma das zoonoses que vem preocupando as autoridades sanitárias de todo o mundo. Sua ocorrência se deve principalmente os distúrbios ecológicos é transmitida ao homem através de inalação de partículas virais contida na excreta de roedores. São conhecidas duas doenças humanas distintas causadas pelo Hantavírus: a Febre Hemorrágica com Síndrome Renal (FHSR) e a Síndrome Pulmonar e Cardiovascular (SPCVH). O objetivo deste estudo foi verificar a ocorrência de anticorpos IgG anti-hantavírus, através do ELISA, em populações da Amazônia e Sudeste brasileiro, que vivem em contato com os roedores silvestres, utilizando a proteína recombinante do vírus Araraquara expressa em Escherichia coli. Do total de estudados 1308 soros humanos estudados, na Amazônia (1078) encontramos 59 soros positivos (5%). Na cidade Machadinho do OesteRO os soros coletados durante o ano 2003, foram analisados 638, onde foram encontrados 20 soros positivos (4,5%); e no Rio Machado RO. foram analisados 435 soros da população ribeirinha onde foram encontrados 39 (5%) soros positivos, respectivamente. Após análise realizada em 151 soros humanos provenientes do Vale do Ribeira, em 2007; e 84 no Pontal do Paranapanema, em 2008, foram observados 14 positivos (9%) e 6 (7%) das amostras, respectivamente. / The genus Hantavirus of the family Bunyaviridae includes a large number of rodent-borne viruses that are distributed worldwide. The occurrence is due mainly to ecological disturbances and it is transmitted to the humans through inhalation of virus particles contained in the excreta of wild rodents. Two different human diseases known to be caused by Hantavirus: are Hemorrhagic Fever with Renal Syndrome (HFRS) and Hantavirus Cardiopulmonary Syndrome (HPS). The main objective of this study was detected antibody against hanatavirus (IgG) by ELISA, in Amazon region and Brazilian Southwest populations who live in contact with the wild rodents, using recombinant protein (antigen) of the Araraquara virus expressed in Escherichia coli. We study 1308 human sera (1078 from Amazon region) and there were found 59 (5%) positive sera. From the city of Machadinho do Oeste RO (2003 year), 633 sera were analysed, where there were found to be 20 positive (4.5%) serums. In Machado river RO (2005 year), 435 sera of the river-dwelling population were analysed where there were found 39 (5%) positive sera, respectively. After analysis was accomplished for 151 human sera coming from the Vale do Ribeira - SP, in 2007, and 84 from the Pontal do Paranapanema - SP, in 2008, 14 (9%) and 6 (7%) of the samples were observed to be positive, respectively.
79

Ocorrência de anticorpos anti-hantavírus (IgG) em populações humanas na região Amazônica e no estado de São Paulo (Mata Atlântica), utilizando proteína recombinante (nucleocapsídio) do vírus Araraquara. / Detection of antibodies (IgG) against hantavirus in human population of Amazon region and the state of Sao Paulo (Atlantic Forest), using recombinant antigen of Araraquara virus.

Felipe Alves Morais 11 November 2010 (has links)
A hantavirose (infecção por Hantavírus) é uma das zoonoses que vem preocupando as autoridades sanitárias de todo o mundo. Sua ocorrência se deve principalmente os distúrbios ecológicos é transmitida ao homem através de inalação de partículas virais contida na excreta de roedores. São conhecidas duas doenças humanas distintas causadas pelo Hantavírus: a Febre Hemorrágica com Síndrome Renal (FHSR) e a Síndrome Pulmonar e Cardiovascular (SPCVH). O objetivo deste estudo foi verificar a ocorrência de anticorpos IgG anti-hantavírus, através do ELISA, em populações da Amazônia e Sudeste brasileiro, que vivem em contato com os roedores silvestres, utilizando a proteína recombinante do vírus Araraquara expressa em Escherichia coli. Do total de estudados 1308 soros humanos estudados, na Amazônia (1078) encontramos 59 soros positivos (5%). Na cidade Machadinho do OesteRO os soros coletados durante o ano 2003, foram analisados 638, onde foram encontrados 20 soros positivos (4,5%); e no Rio Machado RO. foram analisados 435 soros da população ribeirinha onde foram encontrados 39 (5%) soros positivos, respectivamente. Após análise realizada em 151 soros humanos provenientes do Vale do Ribeira, em 2007; e 84 no Pontal do Paranapanema, em 2008, foram observados 14 positivos (9%) e 6 (7%) das amostras, respectivamente. / The genus Hantavirus of the family Bunyaviridae includes a large number of rodent-borne viruses that are distributed worldwide. The occurrence is due mainly to ecological disturbances and it is transmitted to the humans through inhalation of virus particles contained in the excreta of wild rodents. Two different human diseases known to be caused by Hantavirus: are Hemorrhagic Fever with Renal Syndrome (HFRS) and Hantavirus Cardiopulmonary Syndrome (HPS). The main objective of this study was detected antibody against hanatavirus (IgG) by ELISA, in Amazon region and Brazilian Southwest populations who live in contact with the wild rodents, using recombinant protein (antigen) of the Araraquara virus expressed in Escherichia coli. We study 1308 human sera (1078 from Amazon region) and there were found 59 (5%) positive sera. From the city of Machadinho do Oeste RO (2003 year), 633 sera were analysed, where there were found to be 20 positive (4.5%) serums. In Machado river RO (2005 year), 435 sera of the river-dwelling population were analysed where there were found 39 (5%) positive sera, respectively. After analysis was accomplished for 151 human sera coming from the Vale do Ribeira - SP, in 2007, and 84 from the Pontal do Paranapanema - SP, in 2008, 14 (9%) and 6 (7%) of the samples were observed to be positive, respectively.

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