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Mitochondrial Function as a Determinant of Life SpanLanza, Ian R., Nair, K. S. 01 January 2010 (has links)
Average human life expectancy has progressively increased over many decades largely due to improvements in nutrition, vaccination, antimicrobial agents, and effective treatment/prevention of cardiovascular disease, cancer, etc. Maximal life span, in contrast, has changed very little. Caloric restriction (CR) increases maximal life span in many species, in concert with improvements in mitochondrial function. These effects have yet to be demonstrated in humans, and the duration and level of CR required to extend life span in animals is not realistic in humans. Physical activity (voluntary exercise) continues to hold much promise for increasing healthy life expectancy in humans, but remains to show any impact to increase maximal life span. However, longevity in Caenorhabditis elegans is related to activity levels, possibly through maintenance of mitochondrial function throughout the life span. In humans, we reported a progressive decline in muscle mitochondrial DNA abundance and protein synthesis with age. Other investigators also noted age-related declines in muscle mitochondrial function, which are related to peak oxygen uptake. Long-term aerobic exercise largely prevented age-related declines in mitochondrial DNA abundance and function in humans and may increase spontaneous activity levels in mice. Notwithstanding, the impact of aerobic exercise and activity levels on maximal life span is uncertain. It is proposed that age-related declines in mitochondrial content and function not only affect physical function, but also play a major role in regulation of life span. Regular aerobic exercise and prevention of adiposity by healthy diet may increase healthy life expectancy and prolong life span through beneficial effects at the level of the mitochondrion.
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Avaliacao do efeito da radiacao de Co-60 na sobrevida de diferentes linhagens de camundongos .Radiomodificadores e resposta celularVILLAVICENCIO, ANNA L.C.H. 09 October 2014 (has links)
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03369.pdf: 1560275 bytes, checksum: 905c046cbaa9aa4972b03e4674cdde9a (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Avaliacao do efeito da radiacao de Co-60 na sobrevida de diferentes linhagens de camundongos .Radiomodificadores e resposta celularVILLAVICENCIO, ANNA L.C.H. 09 October 2014 (has links)
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03369.pdf: 1560275 bytes, checksum: 905c046cbaa9aa4972b03e4674cdde9a (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Identifica??o e quantifica??o de hem?citos de f?meas ingurgitadas de Boophilus microplus inoculados com fungos Metarhizium anisopliae, Beauveria bassiana, Penicillium corylophilum e Fusarium oxysporum. / Identification and quantification of hemocytes obtained from engorged females of Boophilus microplus (Canestrini, 1887) (Acari: Ixodidae) inoculated with Metarhizium anisopliae, Beauveria bassiana, Penicillium corylophilum and Fusarium oxysporumSilva, Sandra Borges da 24 February 2006 (has links)
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Previous issue date: 2006-02-24 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Biological control of the tick Boophilus microplus with Metarhizium anisopliae and
Beauveria bassiana has been evaluated by several researchers. The selection of
specimens resistant to chemical products is a mechanism used by arthropods for
survival and maintenance in the environment. It is already known how fungi penetrate
the host and their pathogenic potential at different phases of their biological cycle,
however, ticks immune response against these agents need more detailed studies. The
present work had as objectives: to identify and quantify the cellular types involved in
the cellular response of B. microplus inoculated with entomopathogenic (M. anisopliae
and B. bassiana) and non-entomopathogenic fungi (Penicillium corylophilum and
Fusarium oxysporum). In this study 60 engorged females of B. microplus were used,
representing six treatment groups with 10 specimens each. Ticks were inoculated with
aqueous suspension of conidia. There were two control groups: in the first one ticks
were inoculated with Tween 80 0,1% aqueous solution (negative control), in the second
one ticks were not inoculated (testimony group). Fungi suspension or Tween 80 solution
were applied in the back part of the idiosoma of the tick. The hemolinfa samples were
collected during the whole period of life of the specimens, beginning 24 hours after
inoculation. The haemolymph samples were fixed in methanol and stained with Giemsa.
In all studied periods, cells like pro-hemocytes, plasmatocytes, granulocytes,
spherulocytes and oenocytoids were observed in the specimens of all groups. Prohemocytes,
plasmatocytes and spherulocytes were the most numerous cells observed in
the hemolinfa. Hemocytes were absent in the group inoculated with B. bassiana 72
hours after inoculation. After this period, specimens inoculated with entomopathogenic
fungi were dead. The absence of cells suggests the immune-suppressor effect of the
fungi on this tick species. It was not observed when ticks were treated with M.
anisopliae due to accentuated mortality caused by this fungus species. The nonentomopathogenic
fungi did not affect the life cycle of this tick, being quickly
eliminated of the organism. It was suggested based on the absence of conidia during
sampling. / O controle biol?gico do carrapato Boophilus microplus com a utiliza??o de Metarhizium
anisopliae e Beauveria bassiana tem sido avaliado por diversos pesquisadores. A
sele??o de cepas resistentes ? um mecanismo adotado pelos artr?podes para
sobreviv?ncia da esp?cie e sua manuten??o no ambiente. Apesar de estar esclarecida a
forma como o fungo penetra no hospedeiro e comprovada sua patogenicidade sobre
diferentes fases de seu ciclo biol?gico, a sua resposta imune frente a estes agentes
agressores necessita de maiores estudos. O presente trabalho teve como objetivo:
identificar e quantificar os tipos celulares envolvidos na resposta imune celular de B.
microplus inoculados com fungos entomopatog?nicos n?o entomopatog?nicos. Na
experimenta??o foram utilizados 60 f?meas ingurgitadas de Boophilus microplus,
representando seis tratamentos cada um contendo 10 esp?cimes. Para os grupos
inoculados com fungos entomopatog?nicos foi utilizada a suspens?o aquosa dos fungos
Metarhizium anisopliae (isolado Ma 959) e Beauveria bassiana (isolado Bb 986). Nos
tratamentos com fungos n?o entomopatog?nicos, Penicillium corylophilum e Fusarium
oxysporum, foram formados ainda um grupo testemunha (n?o recebeu inocula??o) e um
grupo inoculado com solu??o de tween 80 a 0,1% em ?gua destilada est?ril, considerado
controle negativo. Nos grupos dos tratamentos com suspens?o f?ngica ou solu??o a
inocula??o foi feita na regi?o posterior do idiossoma do carrapato. As coletas de
hemolinfa foram realizadas durante todo o per?odo de vida dos esp?cimes, tendo inicio
24 horas ap?s inocula??o. As amostras de hemolinfa foram fixadas com metanol e
coradas com Giemsa. Em todos os per?odos estudados, tanto nos esp?cimes inoculados
com fungos como nos controles, foram observados pr?-hem?citos, plasmat?citos,
granul?citos, esferul?citos e oenocit?ides. Pr?-hem?citos, plasmat?citos e esferul?citos
foram ?s c?lulas mais numerosas na hemolinfa. Foi observada a aus?ncia de hem?citos
no grupo inoculado com B. bassiana 72 horas ap?s a inocula??o, como tamb?m a morte
dos esp?cimes inoculados com fungos entomopatog?nicos a partir deste per?odo. A
aus?ncia de c?lulas evid?ncia o efeito imunossupressor do fungo sobre os carrapatos
estudados. Caracter?stica n?o observada para Metarhizium anisopliae, mesmo tendo
provocado acentuada mortalidade dos carrapatos. Os fungos n?o entomopatog?nicos
n?o afetaram de forma significativa o ciclo de vida destes carrapatos, sendo rapidamente
eliminados do organismo.
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The heat shock protein 90 (HSP90) chaperone complex regulates heat shock factor 1 (HSF) in <i>Xenopus laevis</i> oocytesBharadwaj, Steven Charles 01 January 2001 (has links)
Stress-induced heat shock protein (HSP) gene transcription is controlled primarily by the transcription factor heat shock factor 1 (HSF1). HSF1 activation involves trimerization, heat shock element (HSE)-binding, and transactivation. During prolonged stress or upon removal of stress HSF1 activity attenuates. The mechanism(s) regulating HSF1 activity are unknown. Some reports have suggested that HSF1 may be regulated in some manner by the HSP90 chaperone (Nadeau, K., 'et.al.', 1993; Nair, S., 'et.al.', 1996). Utilizing the 'Xenopus' oocyte model system I tested the hypothesis that the HSP90 chaperone machine, known to function in the folding and maturation of molecules such as steroid receptors, might also participate in HSF1 regulation. Characterization experiments illustrated that the 'Xenopus' oocyte was capable of responding to some but not all forms of stress at the level of HSF1-HSE binding illustrating that certain stress pathways may be absent or inactive in the oocyte. Through transcriptional assaysit was also shown that HSF1-DNA binding and transactivation are regulated by independent mechanisms in the oocyte. HSP90 was shown to interact with and regulate the activity of HSF1 in oocytes. HSP90-HSF1 associations were illustrated ' in vivo' and 'in vitro' by co-immunoprecipitation and gel supershift assays. Immunotargeting HSP90 caused activation of HSF1 under control conditions and delayed deactivation during recovery. These data support a role for HSP90 in the oligomeric changes associated with HSF1 activation/deactivation. Immunotargeting HSP90 also inhibited HSF1 dependent transcription, supporting a role for HSP90 in mediating HSF1 transcriptional activity. HSP90 does not regulate HSF1 alone. Gel supershift analysis showed that p23, HSP90 and FKBP52 exist in a complex with activated HSF1. Furthermore, elevating the levels of various co-chaperones through injection of protein or mRNA had various effects on HSF1 during recovery from stress. Immunotargeting HSP90 or p23 induced HSF1-DNA binding in the absence of stress indicating these proteins may act together to repress HSF1 'in vivo'. Furthermore, injection of HSP90, Hip, Hop, p23, FKBP51, and FKBP52 antibodies significantly delayed HSF1 deactivation supporting a role for these proteins in trimer disassembly. Therefore multiple components of the HSP90 chaperone complex function to regulate HSF1 during its activation and/or deactivation cycle.
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Preparation of a site-specific lymphotoxin- mutant to be used in protein characterization and receptor binding studiesKnight, Derek Andrew 01 January 1995 (has links)
No description available.
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Efeito do extrato aquoso da casca do caule da Bowdichia virgilioides KUNTH na resposta celular e humoral em camundongos / Effect of aquous extract of Bowdichia virgilioides KUNTH derived stem bark in cellular and humoral responses in micesBrandão, Altair Rogério Alves 26 March 2012 (has links)
Bowdichia virgilioides Kunth, popularly known as "sucupira preta", is used in folk regional medicine to combat inflammation, autoimmune diseases and healing. There are only few scientific studies dealing with its biological activity, especially in regards to the immune system, making it a potential target of scientific research. The aim of this study was to evaluate in vivo the action of the aqueous extract of Bowdichia virgilioides-derived stem bark (EaBv) in cellular and humoral responses. Swiss male mices were used (4-6 weeks), which were administered EaBv orally for 7 consecutive days. Initially using the template of zymosan A showed that treatment with EaBv increased phagocytic capacity of resident peritoneal macrophages. On the peripheral blood leukocytes count, it was observed a decrease in the number of total leukocytes in animals treated with EaBv and this reduction was observed when the differential number of neutrophils counts was performed. However, the increased number of lymphocytes in peripheral blood of animals after treatment. It has been found by the hemagglutination assay EaBv was able to decrease the production of antibodies. The extract stimulated proliferation of lymphocytes which have been obtained from lymph nodes after 7 days of treatment. Also, interfered with the effect of ConA on T lymphocyte proliferation and acted negatively on the action of LPS on the proliferation of B lymphocytes. Furthermore, flow cytometric, it was observed that the EaBv increased expression of TNF-α by T lymphocytes and IL-10 by B lymphocytes. However, expression of TNF-α by B lymphocytes has been modulated negatively by the extract. Together, these results suggest that aqueous extract of Bowdichia virgilioides-derived stem bark possesses a complexe immune activity, acting on the cellular and humoral immune responses. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Bowdichia virgilioides Kunth, popularmente conhecida como sucupira-preta , é espécie utilizada na medicina popular regional no combate a inflamação, doenças auto-imunes e cicatrizante. Ainda são escassos os estudos que tratam da sua atividade biológica, principalmente em relação ao sistema imunológico, o que a torna um alvo em potencial de investigações científicas. O objetivo desse trabalho foi avaliar in vivo a ação do extrato aquoso da casca do caule da Bowdichia virgilioides (EaBv) na resposta imunológica celular e humoral. Foram utilizados camundongos Swiss (4-6 semanas) machos, aos quais foi administrado por via oral o EaBv durante 7 dias consecutivos. Inicialmente, utilizando o modelo de zimosan A demonstrou-se que o tratamento com EaBv aumentou a capacidade fagocítica de macrófagos peritoneais residentes. Na contagem de leucócitos do sangue periférico, observou-se uma diminuição no número de leucócitos totais nos animais tratados com EaBv e esta diminuição foi evidenciada no número de neutrófilos quando realizada a contagem diferencial. No entanto, o número de linfócitos aumentou no sangue periférico dos animais após o tratamento. Verificou-se pelo ensaio de hemaglutinação que o EaBv foi capaz de diminuir a produção de anticorpos. O extrato estimulou a proliferação dos linfócitos totais que foram obtidos dos linfonodos mesentéricos após os 7 dias de tratamento. Além disso, interferiu na ação da concanavalina A sobre a proliferação de linfócitos T, e agiu negativamente na ação do lipopolissacarídeo sobre a proliferação de linfócitos B. Ainda, por citometria de fluxo, observou-se que o EaBv aumentou a expressão das citocinas TNF-α nos linfócitos T e IL-10 nos linfócitos B. Entretanto, a expressão de TNF-α pelos linfócitos B foi modulado negativamente pelo extrato. Em conjunto, os resultados sugerem que o extrato aquoso da casca do caule Bowdichia virgilioides possui uma atividade imunológica complexa, agindo sobre as respostas imunes celular e humoral.
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Avaliação do padrão de resposta de imunoglobulinas em diferentes linhagens de camundongos frente à infecção por T.cruziSILVA, ANDREIA dos S. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:52:28Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:00:43Z (GMT). No. of bitstreams: 0 / O presente trabalho realizou-se com diferentes linhagens de camundongos (A/J, C57BL/6, B6AF1, BXA1 e BXA2) que foram desafiados com diferentes doses da cepa Y de T. cruzi. O objetivo foi avaliar o padrão de resposta de imunoglobulinas produzidas por estas linhagens e para tanto, amostras de soros foram analisadas pelo método imunoenzimático. A partir dos resultados obtidos observou-se que todas as linhagens apresentaram uma resposta superior para IgG2a e IgG2b, quando comparados ao IgG1. Indicando um padrão Th1 que expressa resposta imunológica celular. As diferentes linhagens utilizadas nessa pesquisa apresentam padrões de resposta imunológica também diferentes frente à infecção por T. cruzi. Animais da linhagem C57BL/6 mostraram-se resistentes a infecção, enquanto que os animais da linhagem A/J mostraram-se susceptíveis, corroborando com a literatura. Os animais da linhagem híbridos B6AF1 foram mais resistentes à infecção que seu parental original C57BL/6. Sua resposta imunológica apresenta traços tanto do parental original A/J quanto do C57BL/6. Os animais da linhagem BXA1 puderam ser considerados resistentes à infecção, mas não apresentaram o mesmo controle observado nos animais das linhagens B6AF1 e C57BL/6. Os animais da linhagem BXA2 foram considerados susceptíveis à infecção, mas a controlaram por um período maior, sobrevivendo assim, por tempo superior àquele observado na linhagem A/J. Os resultados obtidos indicam que a subclasse de imunoglobulinas IgG2b desempenha importante papel na resistência à cepa Y de T. cruzi. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Immune Responses to Gene Product of Inducible PromotersLe Guiner, Caroline, Stieger, Knut, Synder, Richard O., Rolling, Fabienne, Moullier, Philippe 01 October 2007 (has links)
Efficient gene transfer has been achieved in several animal models using different vector systems, leading to stable transgene expression. The tight control of this expression is now an important outcome for the field of gene therapy. Such regulation is likely to be required for therapeutic applications and in some instances for safety reasons. For this purpose, several regulatable systems depending on small molecules have been developed. Among these, the tetracycline and the rapamycin dependent systems have been largely used. However, if long-term regulation of the transgene has been obtained in small animal models using these inducible systems, when translational studies were initiated in larger animals, the development of an immune response against proteins involved in transgene regulation were often observed. Such immune response was especially documented when using the TetOn tetracycline regulatable system in nonhuman primates (NHP). Humoral and destructive cellular immune responses against the transactivator involved in this regulation system were documented in a large majority of NHP leading to the complete loss of the transgene regulation and expression. This review will describe the immune responses observed in these different model systems applied for transgene regulation. Focus will be finally given on future directions in which such immune responses might be surmounted, enabling long-term transgene regulation in future clinical developments of gene transfer.
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Dynamique des réponses lymphocytaires T locales et systémiques à l'injection d'un vaccin dans la peau / Dynamic of local and systemic cellular responses after vaccination in the skinJoly, Candie 26 September 2019 (has links)
La vaccination est considérée comme l’un des plus grandes découvertes de l’histoire des maladies infectieuses, ayant permis le déclin et l’éradication de plusieurs pathogènes. Cependant, nous ignorons encore tous les mécanismes impliqués dans la protection contre les pathogènes. Cette méconnaissance est la cause de notre incapacité à formuler des nouveaux vaccins contre le VIH, la tuberculose, le paludisme et les pathogènes émergents. Récemment, on note des efforts pour induire une réponse cellulaire efficace après une vaccination, qui joue un rôle crucial dans la clairance des pathogènes.Cette thèse s’appuie sur un modèle de vaccin vivant atténue issu du virus de la vaccine : le MVA (Modified Vaccinia Ankara) et sur le modèle de primate non-humain. Nous avons caractérisé la réponse cellulaire après une immunisation intradermique suivant un schéma en prime-boost homologue, avec un boost à 2, suivi d’un boost à 9 mois. Le MVA a induit une infiltration massive de Lymphocytes T CD8 au niveau du site d’injection, 7 jours après l’immunisation. La réponse cellulaire systémique était modérée et ne reflétait pas l’amplitude de la réponse locale. Les injections du prime et du boost ont orienté la réponse cellulaire de façon différente, ce qui a mené à une importante induction de cellules T CD4 et CD8, persistantes, spécifiques de l’antigène et polyfonctionnelles après l’injection du boost à 9 mois.Cette étude souligne la différence entre les réponses systémiques et locales, démontrant l’importance de se focaliser sur la réponse tissulaire. Elle a également mis en lumière l’impact du schéma d’immunisation sur la qualité de la réponse cellulaire. / Vaccination has been considered as one of the greatest discoveries in the history of infectious diseases by allowing pathogens decline or eradication. However, we still ignore all the mechanism that lead to protection and therefore, fail to elaborate new vaccines against HIV, tuberculosis, malaria and emergent pathogens. Recently, efforts have been made to elicit effective cellular response after vaccination, which is crucial for pathogen clearance.This thesis relied on live-attenuated vaccine model derived from the vaccinia virus: the MVA (Modified Vaccinia Ankara) and a non-human primate model. We characterized the cellular immune response triggered by a homologous prime-boost intradermal injection of MVA, with a 2 months and 9 months boost. The MVA induced a massive infiltration of CD8 T cells at the injection site 7 days post immunization. In comparison, the systemic cellular response was mild and did not reflect the magnitude of the local response. The prime and boost injections elicited distinct orientation of the systemic and local T cells, which led to an important induction of a persistent, antigen-specific and polyfunctional CD8 and CD4 T cell responses after the 9 months boost.This work emphasizes the difference between local and systemic response, demonstrating the importance of the focus on tissue immunity. It also highlights the impact of the immunization schedule on the quality of the cellular response.
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