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T Lymphocyte Apoptosis and Memory in Viral Infection: A DissertationRazvi, Enal Shahid 01 November 1994 (has links)
Acute viral infections in humans and mice induce T lymphocyte responses which mediate viral clearance and result in the establishment of immunological memory. The course of an immune response to acute viral infection is associated with an immune deficiency in the lymphocyte compartment. This is usually characterized by the inability of lymphocytes to productively respond to mitogen or recall antigen. This thesis examined the acute lymphocytic choriomeningitis virus (LCMV) infection of the mouse and showed that T lymphocytes isolated from acutely LCMV-infected mice underwent activation-induced apoptosis upon signalling through the T-cell receptor (TcR)-CD3 complex. Kinetic studies demonstrated that this sensitivity to apoptosis directly correlated with the induction of immune deficiency, as measured by impaired proliferation in response to anti-CD3 antibody or to concanavalin A. Cell cycling in interleukin-2 (IL-2) alone stimulated proliferation of LCMV-induced T cells without inducing apoptosis, but preculturing of T cells from acutely-infected mice in IL-2 accelerated apoptosis upon subsequent TcR-CD3 crosslinking. T lymphocytes isolated from mice after the acute infection were less responsive to IL-2, but IL-2 receptor-bearing T cells, presumably memory T cells, responding to IL-2 were primed in each case to die a rapid apoptotic death upon TcR-CD3 crosslinking. These results indicated that virus infection-induced unresponsiveness to T-cell mitogens is in part attributable to apoptosis of the activated lymphocytes and suggest that the sensitization of memory cells by IL-2 and other stimulatory cytokines induced during an acute infection will cause them to die upon antigen recognition, thereby impairing specific responses to nonviral (recall) antigens.
The cytotoxic T lymphocyte (CTL) response to acute LCMV infection is characterized by a massive (10-20 fold) expansion of CD8+ cell number, which after clearance of virus declines in number and returns to levels present prior to infection. This thesis documents the presence of high levels of apoptotic lymphocytes in situ in the spleens of mice during the silencing of the immune response to acute LCMV infection. Apoptotic cells were detected by an in situ nucleotidyl transferase (ISNT) assay. Both T and B lymphocytes, as revealed by immunohistochemical analysis, are shown to be dying in vivo, the latter in clusters. A biphasic occurrence of apoptosis during the course of the acute infection was found, with an increase in numbers of apoptotic cells above background at day 3 post-infection, and at day 11 post-infection, a second more pronounced peak coincident with the decline of the CTL response to the infection and with the decrease in total spleen leukocyte number. Apoptosis in vivo was detected in lpr mice lacking Fas expression, a molecule involved in lymphocyte apoptosis. Fas expression thus may not be required for lymphocyte apoptosis in the context of an acute viral infection. Apoptosis in situ and the silencing of the CD8+ T lymphocyte response to acute LCMV infection were unaffected by the enforced lymphocyte-directed expression of Bcl-2, a protein blocking IL-2 deprivation-induced apoptosis of lymphocytes. Experiments aimed at addressing the role of Bcl-2-sensitive apoptotic pathways in the development of viral persistence revealed that high-dose infection of Bcl-2-transgenic mice results in death of the animals. Flow cytometric analysis showed an accumulation of Thy1.2+ T cells in the lungs of these animals, and the air spaces in the lungs were occluded with cellular and fluid infiltrates. These results suggest that the pathology seen in the Bcl-2-transgenic mice upon high-dose infection is perhaps immune response-mediated (an immunopathology). This is consistent with a role for Bcl-2-sensitive pathways of lymphocyte apoptosis in the pathogenesis of persistent LCMV infection.
The in situ demonstration of apoptosis in spleens during infection provide direct in vivo evidence for the death of lymphocytes during the recovery from an acute viral infection. This indicates that apoptotic elimination of the population en masse is a mechanism for halting an antiviral immune response upon clearance of virus. Furthermore, the data argue that IL-2 deprivation-driven apoptosis, upon clearance of virus, of the expanded T lymphocyte compartment is not the major mechanism involved in the silencing of the T cell response to acute LCMV infection.
Resolution of an acute immune response leads into the generation of longterm immunological memory. Since this thesis focussed on T cell responses in viral infection, it was important to characterize the in vivo state of memory CD8+ T cells. During acute LCMV infection, the majority of the LCMV-specific CTL activity tested immediately ex vivo was mediated by CD8+ L-selectin-Mac-1+ CTL. The L-selectin- population of CD8+ cells elicited during acute infection also carried >99% of the restimulatable CD8+ CTLp to LCMV, and these required added IL-2 for development into effectors in vitro. In contrast to the acute infection, most of the virus-specific CTLp in immune mice were L-selectin+.
Examination of CD8+ T cells in LCMV-immune mice revealed that a L-selectin+ blast-sized population of cycling CD8+ cells contained CTLp which developed into effector CTL in the absence of added IL-2. These cells also expressed Mac-1 and IL-2R. Flow cytometric sorting for IL-2R+ and IL-2R-CD8+ cells in the immune animal revealed, by limiting dilution analysis, similar frequencies of CTLp in both populations. In bulk restimulation assays, the CD25+ CTLp did not require added IL-2 for their in vitro development into effectors, whereas the CD25- CTLp did. Hence, the different requirements for CTLp to effector development in vitro reflect qualitative differences in the in vivo state of the CTLp in the various subpopulations.
LCMV-specific memory CTLp not requiring added IL-2 for differentiation were also found in the small-sized, non-cycling, CD8+L-selectin- cells. In contrast, the small-sized, non-cycling, CD8+L-selectin+, and CD8+IL-2R- populations also carried CTLp, but these required added IL-2 for development into effector CTL. Hence, T cell memory to LCMV is distributed among various lymphocyte subpopulations in immune animals, and the presence of an activated cycling cell component may account for the stability and long-term perpetuation of antiviral immunological memory.
In summary, the susceptibility of activated T lymphocytes to apoptosis probably explains an aspect of virus-induced immune deficiency and allows for the establishment of homeostasis subsequent to the resolution of an acute viral infection.
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Adjuvant-Specific Serum Cytokine Profiles in the Context of a DNA Prime-Protein Boost HIV-1 Vaccine: A DissertationBuglione-Corbett, Rachel 29 April 2013 (has links)
In recent years, heterologous prime-boost vaccination constructs have emerged as a promising strategy to generate broad and protective immunity against a variety of pathogens. The utility of DNA vaccination in priming the immune system, in particular, has improved the immunogenicity of vaccines against difficult pathogens such as HIV-1. In addition, many vaccine formulations include an adjuvant to augment immune responses. However, the mechanisms and profiles of many adjuvants remain largely unknown, particularly in the context of such combination immunization approaches.
My thesis research studied the effects of several adjuvants, QS-21, aluminum hydroxide, MPL, and ISCOMATRIX™ adjuvant in the context of a previously described pentavalent HIV-1 Env DNA prime-protein boost vaccine, DP6-001. In a murine model, we quantified HIV antigen-specific humoral and T cell responses, as well as pro-inflammatory serum cytokine and chemokines, both shortly after immunization and at the termination of studies. Our data indicates that each candidate adjuvant generates a unique pattern of biomarkers as well as improved immunogenicity in the context of the DP6-001 DNA prime-protein boost vaccine.
Additionally, we examined the impact of several innate signaling pathways on the adaptive immunity raised by DP6-001 and adjuvants, as well as on the unique serum cytokine profiles. These studies provide valuable information in selection of an adjuvant for inclusion in future prime-boost strategies, with the goal of enhancing immunogenicity while minimizing reactogenicity. Furthermore, these studies provided insight about the utility of different current adjuvants in a prime-boost formulation, and the unique immune environment induced by DNA priming.
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Avaliação da função tímica em pacientes com Síndrome de DiGeorge / Assessment of thymic function in patients with DiGeorge SyndromeFomin, Angela Bueno Ferraz 11 March 2010 (has links)
Entre as síndromes de deleção do cromossomo 22q.11, a Síndrome de DiGeorge foi descrita em 1967 como uma imunodeficiência primária caracterizada por: malformações cardíacas, hipoparatireoidismo e ausência de timo. A incidência estimada é de 1: 3000 nascidos vivos e apesar disto seu reconhecimento ainda apresenta dificuldades devido à grande variabilidade fenotípica e diferentes nomenclaturas. Para o diagnóstico é necessário a presença do número de células T circulantes diminuído ou normal, número de células B circulantes normais e níveis séricos de imunoglobulinas diminuídos ou normais associado com os seguintes achados: hipoparatireoidismo, malformações cardíacas conotruncais, dismorfismo facial e detecção da deleção do cromossomo 22q.11. Os pacientes com Síndrome de DiGeorge apresentam graus variados de comprometimento tímico e há a necessidade de avaliação da função tímica objetiva e eficaz para este grupo de pacientes. Recentemente, a mensuração do TREC tem sido considerada adequada para avaliar a função tímica. O objetivo deste estudo foi avaliar a função tímica em pacientes com esta síndrome através de dados clínicos e laboratoriais associados à mensuração do TREC em células mononucleares periféricas. Os objetivos secundários foram descrever as características fenotípicas, as alterações imunológicas incluindo a quantificação de subpopulações de linfócitos T e sua ativação. A quantificação do TREC foi feita através de PCR quantitativo em tempo real e as subpopulações de linfócitos T e dos marcadores de ativação CD28+ e HLA-DR+, através de citometria de fluxo. Nesta casuística foram incluídos 14 pacientes, oito masculinos, com idade entre 8m a 18a11m. Todos os pacientes preencheram os critérios diagnósticos e em dois não foi detectada a deleção do 22q11.2. O achado mais freqüente foi o acometimento cardíaco em 12 pacientes, prevalecendo a tetralogia de Fallot. O dismorfismo facial foi observado em 11 pacientes, sendo as alterações orofaciais as mais comuns. Hipocalcemia esteve presente em cinco pacientes e em um deles havia associação com hipotireoidismo neonatal. Depressão foi observada em dois pacientes e atualmente nenhum paciente apresenta quadro de infecção de repetição. À avaliação da imunidade humoral, detectou-se cinco pacientes com concentrações séricas de IgM abaixo dos valores normais para a idade e na avaliação da anticorpogênese somente três pacientes responderam com títulos protetores para a o esquema vacinal completo para hepatite B e quatro para sarampo. A quantificação do número de TREC realizada em 12 pacientes mostrou-se reduzida em relação aos controles com uma significância estatística (p = 0,002). O número de linfócitos totais estava dentro dos valores normais, mas, os valores de CD3+ estavam diminuídos em nove, CD4+ em um e CD8+ em cinco pacientes. Observou-se maior expressão de marcadores de ativação linfocitária no grupo de pacientes que nos controles (p = 0, 002). Conclusão: Este estudo revelou que os pacientes avaliados apresentaram alteração tanto da imunidade celular como humoral em especial em relação à anticorpogênese pós vacinal e redução da subpopulação de linfócitos T. A reduzida quantidade de TREC em relação aos controles pode indicar uma disfunção tímica embora tenha sido observado normalidade linfocitária nestes pacientes / Among the syndromes of 22q.11 deletion, the DiGeorge Syndrome was first described in 1967 as a primary immunodeficiency characterized by: heart defects, hypoparathyroidism and absence of thymus. The estimated incidence is 1: 3000 live births and despite this, its recognition still presents difficulties due to large variability and different nomenclatures. For the diagnosis it is necessary the presence of the decreased or normal number of circulating T cells, normal number of circulating B cells and decreased or normal levels serum of immunoglobulins associated with the following findings: hypoparathyroidism, conotruncal heart defects, facial dimorphism and detection of 22q.11 deletion. Patients with DiGeorge syndrome have varying degrees of thymic commitment and there is a necessity for an objectively and effectively evaluation of thymic function to this group of patients. Recently, the measurement of TREC has been considered adequate to evaluate the thymic function. The aim of this study was to evaluate the thymic function in patients with this syndrome through clinical and laboratory data associated with the measurement of TREC in peripheral blood mononuclear cells. The secondary objectives were to describe the phenotypic characteristics, immune disorders including quantification of subpopulations of T lymphocytes and their activation. Quantification of TREC was performed by quantitative PCR in real time and the subpopulations of T lymphocytes and activation markers CD28+ and HLA-DR+, by flow cytometry. In this case series included 14 patients, eight male, aged 8m to 18y11m. All patients met the diagnostic criteria and two did not detect the 22q11.2 deletion. The most common finding was cardiac involvement in 12 patients, with prevalence of tetralogy of Fallot. The facial dimorphism was observed in 11 patients with orofacial changes being the most common. Hypocalcaemia was present in five patients and one of them was associated with neonatal hypothyroidism. Depression was observed in two patients and now, no patient presents recurrent infections. In the humoral immunity, we have found five patients with serum IgM below normal for age and only three patients responded with protective levels of antibodies to the complete vaccine schedule for hepatitis B and four for measles. The measurement of the number of TREC was performed in 12 patients and it was reduced compared to controls with a statistical significance (p = 0, 002). The total number of lymphocytes were within the normal range, but the values of CD3+ were decreased in nine, CD4+ in one and CD8+ in five patients. It was found a higher expression of markers of lymphocyte activation in the group of patients than in controls (p = 0, 002). Conclusion: This study revealed that in the patients studied both humoral and cellular immunity was compromised, in particular in relation to vaccinal response and reduction the subpopulation of T lymphocytes. The reduced amount of TREC when compared to controls may indicate a thymic dysfunction despite the normal lymphocytes in these patients
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Efeito das células dendríticas na geração de células T CD4+CD25+Foxp3+. / Effect of dendritic cells on the generation of CD4+CD25+Foxp3+ T cells.Marguti, Ivo 10 August 2007 (has links)
As células dendríticas (DCs) são as principais células apresentadoras de antígeno do sistema imune. No entanto, trabalhos têm demonstrado seu envolvimento na manutenção da tolerância imunológica. As células T CD4+CD25+Foxp3+ possuem a capacidade de suprimir respostas imunes. Neste estudo avaliamos as alterações ocorridas na população de células T CD4+CD25+Foxp3+ após co-cultura de células de linfonodo com DCs. Nossos resultados demonstram que após a co-cultura há um aumento da população de células CD4+CD25+Foxp3+ de maneira independente do estado de ativação das DCs ou da presença de antígenos exógenos. No entanto, o aumento observado é maior quando DCs imaturas são incubadas com antígenos exógenos. Notamos ainda que há presença de TGF-ß em todas as condições experimentais em que observamos aumento da população de células CD4+CD25+Foxp3+. Nossos dados sugerem ainda que este aumento se deve à proliferação das células T CD4+CD25+Foxp3+. / Dendritic cells (DCs) are the most important antigen-presenting cells of the immune system. However, DCs have also been implicated in maintaining immunologic tolerance. CD4+CD25+Foxp3+ T lymphocytes are known as cells with regulatory properties. In this study we evaluated the changes in the CD4+CD25+Foxp3+ T cell population after co-culture of lymph-node cells with DCs. Our results show an increase in the CD4+CD25+Foxp3+ T cell population after co-culture and occurs regardless of the activation state of DCs and the presence of exogenous antigens; however it is greater when immature DCs are previously pulsed with exogenous antigen. We also noticed that TGF-? is present in all cultures conditions in which the CD4+CD25+Foxp3+ T cell population increases. Our data also suggests that the increase of the CD4+CD25+Foxp3+ T cell population may be due to the proliferation of these cells.
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Análise da resposta imunológica celular da via Th17 em pacientes portadores de dermatofitose extensa e/ou persistente causada pelo Trichophyton rubrum / Analysis of the cellular immune response of the Th17 pathway in patients presenting extensive ando r persistente dermatophytosis caused by Trichophyton rubrumSantana, Grazielle Barbosa 01 September 2016 (has links)
Em países tropicais como o Brasil, as micoses superficiais (dermatofitoses) são comumente encontradas. O Dermatófito mais comum é o Trichophyton rubrum (Tr). Mananas e galactomananas na parede do Tr podem suprimir a resposta celular ao fungo. Quanto à resposta imune antifúngica, sabe-se a importância da via Th17. Algumas lectinas do tipo C (CLRs) como o receptor de manose e/ou receptores similares a Toll (TLRs) regulam o equilíbrio entre as vias Th1 e Th17. Nossos objetivos foram obter um extrato antigênico de Tr que induza resposta imune celular; quantificar e qualificar a resposta imune de indivíduos controles com lesão branda e de pacientes com dermatofitose extensa e/ou persistente causadas pelo Tr e por fim, avaliar a expressão de CLRs em monócitos do sangue periférico nos mesmos grupos. Para tanto, produzimos 11 extratos antigênicos de Tr. Pudemos observar na eletroforese em gel de poliacrilamida proteínas com pesos moleculares de aproximadamente 70 kDa e 38 kDa para os extratos fúngicos: Extrato TCA - Meta 1, Extrato tindalizado G1 e Extrato Coca 1. Avaliamos a resposta linfoproliferativa de células mononucleares por incorporação de timidina triciada em controles e pacientes ao peptídeo YIIDTGIDID do fungo Tr (Tri R2) e aos extratos antigênicos produzidos em nosso laboratório. Utilizamos como estímulos: PWM, CMA, Tri R2, PMA/Ionomicina. Para os ensaios funcionais avaliamos quatro pacientes e 6 indivíduos controles. Para a fenotipagem das células Th17, Th17MEM, Tc17 e Tc17MEM por citometria de fluxo, utilizamos a análise Booleana no software FlowJo X. A avaliação da expressão dos CLRs: CD206 (Receptor de Manose), Dectin 1 e Dectin 2 em monócitos do sangue periférico de controles e pacientes foi efetuada por citometria de fluxo. Dos 11 extratos produzidos de Tr, 7 se mostraram bons estimuladores para pelo menos um dos controles analisados, expressos como ponto máximo de índice de estimulação (p.m.I.E.). Dentre eles destacamos: Extrato TCA - Meta 1 (p.m. I.E. = 14,49 em 5 ug/mL), Extrato Tindalizado G1 (p.m.I.E. = 23,00 em 2,5 ug/mL) e Extrato Coca 1 (p.m.I.E. = 173,36 em 0,31 ug/mL). Na avaliação da expressão dos receptores das células Th17 e Tc17 (Th17R e Tc17R, respectivamente) após seis dias de estímulo por: Tri R2, extrato Coca 1 e o extrato TCA - Meta 1, o extrato Coca se mostrou o melhor estimulador para as populações Th17, com a frequência de 8,40% (controle) e 12,30% (paciente 1). Na avaliação da expressão de Th17R e Tc17R por 6 horas ao estímulo por PMA/Iono, todos os controles (n=3) se mostraram responsivos e no grupo de pacientes (n=3) pudemos observar maior frequência para o paciente 1 nas populações Th17 (1,64%) e Th17MEM (3,27%), e para as células Tc17 (10,70%) e Tc17MEM (3,58%). Observamos redução da expressão de CLRs nos pacientes: CD206: média 60,24% (controles) e 21,27% (pacientes), Dectin 1: 22,42% (controles) e 12,06% (pacientes) e Dectin 2: 20,26% (controles) e 4,99% (pacientes). Controles (n=6) e pacientes (n=3). A inovação na produção de extrato antigênico Extrato TCA - Meta 1 encoraja o estudo dos extratos fúngicos, para se obter melhores condições de avaliações imunológicas em pacientes com dermatofitose. Caracterizamos e qualificamos a resposta imune celular frente ao peptídeo TriR2 e aos extratos antigênicos, além de avaliarmos a expressão dos CLRs nesse grupo especial de pacientes / In tropical countries like Brazil, superficial fungal infections (dermatophytosis) are commonly found. The most common dermatophyte is Trichophyton rubrum (Tr). Mannans and galactomannans of Tr cell wall can suppress cellular responses to the fungus. Regarding the antifungal immune response, the importance of Th17 pathway is warranted. Some C-type lectins (CLRs) as the mannose receptor and / or Toll-like receptors (TLRs) regulate the balance between Th1 and Th17 pathways. Our objectives were to obtain an antigenic extract of Tr to induce cellular immune response; to quantify and classify the immune response of control subjects with mild injury and patients with extensive and / or persistent dermatophytosis caused by Tr, and finally evaluating the expression of CLRs in peripheral blood monocytes in the same groups. Therefore, we produced 11 antigenic extracts of Tr. Proteins with molecular weights of approximately 70 kDa and 38 kDa were evidenced in polyacrylamide gel electrophoresis for the following fungal extracts: extract TCA - Target 1, Tindalized extract G1 and extract Coca 1. We assessed the lymphoproliferative response of mononuclear cells by tritiated thymidine incorporation in the controls and patients, stimulated by YIIDTGIDID peptide fungus Tr (Tri R2) and the antigenic extracts produced in our laboratory. We used as stimuli: PWM, CMA, Tri R2, and PMA/Iono. For functional assays we evaluated four patients and 6 control individuals. For the phenotyping of Th17 cells, Th17MEM, Tc17 and Tc17MEM by flow cytometry, we used a Boolean analysis performed by FlowJo X software. Evaluation of the expression of CLRs: CD206 (mannose receptor), Dectin 1 and Dectin 2 in peripheral blood monocytes from patients and controls was performed by flow cytometry. Of the 11 extracts produced from Tr, seven proved to be able to stimulate proliferation of peripheral blood mononuclear cells of at least one of the analyzed controls, expressed as peak stimulation index (p.m.I.E.). Among them, were included: extract TCA - Target 1 (pmIE = 14.49 at 5 ug /mL), Tindalized G1 Extract (pmIE = 23,00 at 2.5 ug /mL) and extract Coca 1 (pmIE = 173.36 at 0.31 ug /mL). In the evaluation of the expression of receptors of Th17 cells and Tc17 (Th17R and Tc17R, respectively) after six days of stimulation by: Tri R2, Coca extract and the extract TCA 1 - Meta 1, Coca extract showed to be the best stimulator for Th17 populations, with the frequency of 8.40% (control) and 12.30% (patient 1). In the evaluation of the expression of Th17R and Tc17R after 6 hours of stimulation by PMA / Iono, all controls (n = 3) responded and in the group of patients (n = 3) we observed response more frequently for the patient #1, in Th17 populations (1.64%), Th17MEM (3.27%), Tc17 cells (10.70%) and Tc17MEM (3.58%). We observed a reduction of expression of CLRs in patients: CD206: average 60.24% (controls) and 21.27% (patients), Dectin 1: 22.42% (controls) and 12.06% (patients) and Dectin2: 26% (controls) and 4.99% (patients). Controls (n = 6) and patients (n = 3). Innovation in the production of antigenic extract extract TCA - Target 1 encourages the study of fungal extracts to obtain better conditions of evaluation of the immune response in patients with dermatophytosis. We characterized and qualified the cellular immune response to the TriR2 peptide, to antigen extracts, and evaluated the expression of CLRs in this special group of patients
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Fontes de lipídios dietéticos e desempenho imunológico do pacu Piaractus mesopotamicus / Sources of dietary lipids and immune performance of pacu Piaractus mesopotamicusSilva, Thyssia Bomfim Araújo da 02 August 2011 (has links)
A ingestão de lipídios e seus constituintes, os ácidos graxos, são essenciais na manutenção do crescimento, na eficiência alimentar, na higidez do organismo, no funcionamento adequado dos rins e das brânquias e na reprodução. Este estudo visa identificar a influência exercida pelos lipídios dietéticos sobre as variáveis hematológicas e desempenho imunológico de pacus Piaractus mesopotamicus expostos à ação bacteriana. Juvenis de pacu (14,4 ± 0,4g) foram alimentados com dietas contendo níveis crescentes (20, 40, 60, 80, 100%) de óleo de linhaça (OL), óleo de girassol (OG) e sebo bovino (SB), ricas em ômega-3, ômega-6 e gordura saturada, respectivamente e, posteriormente, comparadas a uma dieta isenta destas fontes e a uma ração comercial. Os resultados obtidos foram submetidos a uma análise das variâncias, rearranjados em grupos e analisados sob o teste de Dunnett. Os níveis dietéticos de 20% de óleo de linhaça, 80% de óleo de girassol ou 80% de sebo bovino condicionaram as melhores taxas de desempenho zootécnico; o uso de 80% de óleo de girassol foi o mais adequado para ganho de peso (67,51±4,950g), taxa de conversão alimentar (1,05±0,088) e taxa de crescimento específico (2,19±0,085%), assim como para o aumento no número de linfócitos (1.964,13 ± 413,550), concomitante ao aumento dos leucócitos (1.986,00 ± 256,700), o que conferiu maior resistência aos animais, quando expostos à bactéria Aeromonas hydrophila. / The intake of lipids and its components, the fatty acids, are essential for proper growth, feed efficiency, health, appropriate kidney and gills function and reproduction performance. This study aims at identifying effects of dietary lipids on hematological variables and immunological performance of pacu Piaractus mesopotamicus exposed to bacterial challenges. Performance of juvenile pacu (14.4 ± 0.4 g) fed a diet with increasing levels (20, 40, 60, 80, 100 %) of linseed oil (LO); sunflower oil (80) and beef tallow (BT), rich in omega-3, omega-6 fatty acids, and saturated fat, respectively, was contrasted to the performance of fish fed diets containing soybean oil as lipid source, and a commercial aquafeed. Recorded results were subjected to ANOVA, grouped and submitted to Dunnett\'s test. Dietary levels of 20 % LO, 80% 80 or 80% beef tallow yielded the best growth performance; fish fed 80% 80 had the best weight gain (67.51 ± 4.95 g), best feed conversion ratio (1.05 :t 0.10), specific growth rate (2.10 ± 0.10 %), and also increased number of Iymphocytes (1,964.13 ± 413.55) concomitantly to increased number of leukocytes (1,986.00 ± 256.70), which also elicited the best immunological performance to fish challenged with Aeromonas hydrophila.
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Peptídeos urinários no transplante renal humano: busca de um perfil diferencial na tolerância operacional / Urine peptides in human kidney transplantation: research for a differential profile on operational toleranceTakenaka, Maisa Carla Silveira 16 July 2010 (has links)
Um grupo especial de indivíduos transplantados renais mantém a função do enxerto estável após a total retirada da terapia imunossupressora, alcançando um estado imunológico chamado de Tolerância operacional. Ainda não há marcadores moleculares e celulares que discriminem a tolerância no transplante humano, e os seus mecanismos estão sendo investigados. O perfil de peptídeos presentes na urina pode trazer informações importantes sobre o estado fisiopatológico renal. Nós investigamos se a tolerância operacional apresenta um perfil diferencial de peptídeos urinários, potencialmente, relevante para diagnóstico deste estado imunológico, assim como para a compreensão de seus mecanismos. Realizamos análises qualitativas do extrato de peptídeos da urina de indivíduos dos diferentes grupos do estudo: saudáveis (SA, n=6), tolerantes operacionais (TO, n=5), rejeição crônica (RC, n=8) e estável sob terapia imunossupressora convencional (EST, n=5), utilizando a abordagem proteômica de Shotgun. Identificamos um total de 15283 diferentes peptídeos em todos os grupos, correspondentes a 646 proteínas distintas, distribuídas nos diferentes grupos: TO = 189, RC = 296, EST = 205 e no grupo SA 219 proteínas. Observamos proteínas exclusivas dos diferentes grupos: TO teve 87 proteínas exclusivas, RC 168, EST 106 e SA 108 proteínas. Apesar das proteínas exclusivas não terem sido compartilhadas por todos os indivíduos do mesmo grupo, a totalidade dos indivíduos de cada grupo apresentou várias dessas proteínas (cada indivíduo apresentou em média 15% das proteínas exclusivas de seu grupo). Das 646 proteínas identificadas, apenas 2,3% foram classificadas pelo Gene ontology como relacionadas ao sistema imune e os compartimentos celulares mais frequentes foram: núcleo 36% e citoplasma 23%. Destacamos algumas proteínas relacionadas à resposta imune, exclusivas de alguns grupos, como no grupo TO, a C-C motif chemokine 24 (CCL24) e Endothelin-1 e no grupo RC, a beta 2 microglobulina. Essas moléculas podem ter relevância nos mecanismos imunológicos desses estados clínicos. A abordagem proteômica aplicada neste trabalho permitiu a identificação de um perfil diferencial de peptídeos na urina de cada grupo diferente de estudo. Os peptídeos urinários diferenciais e suas respectivas proteínas podem ter relevância funcional ou como biomarcadores - em relação ao estado fisiológico e às diferentes evoluções clínicas no transplante renal / A special group of renal transplant recipients maintain stable graft function after the complete withdrawal of immunosuppression, achieving a state called operational tolerance. To date, there are no cellular or molecular biomarkers to discriminate human transplantation tolerance and the underlying mechanisms are being investigated. The profile of urinary peptides may provide important information about different renal physiopathological statuses. We investigated whether operational tolerance displays a differential urinary peptide profile, potentially relevant as biomarkers or for the understanding of mechanisms involved in tolerance. We performed qualitative analysis of peptide urinary extracts in individuals from different study groups: healthy (HI, n=6), operational tolerance (OT, n=5), chronic rejection (CR, n=8) e stable under conventional immunosuppression (Sta, n=5), using Shotgun proteomics. Altogether, we identified 15283 different peptides, corresponding to 646 distinct proteins, distributed in all groups: OT = 189, CR = 296, Sta = 205, and 219 proteins in HI. Several proteins were exclusively detected in specific groups: OT showed 87 exclusive proteins, CR 168, Sta 106 and HI 108 proteins. Although the exclusive proteins were not shared by all individuals from that specific group, all individuals from each group presented several of the group-exclusive proteins (each individual presented an average of 15% of the proteins exclusive to his group). Of the 646 proteins identified, only 2.3% were classified in Gene Ontology as related to the immune system and the most frequent cellular compartments were: 36% from nucleus and 23% cytoplasmic. Of notice, some proteins related to the immune response were also group-exclusive, such as, in OT, a C-C motif chemokine 24 (CCL24) and Endothelin-1, and beta 2 microglobulin in CR. These proteins may display relevant roles in the mechanisms involved in these clinical statuses. In conclusion, the proteomic approach used in this study allowed the identification of a differential urinary peptide profile in each different study groups. The differential urinary peptides and their corresponding proteins may display a relevant role functional or as biomarkers - in the state of homeostasis and in different clinical outcomes in renal transplantation
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In vitro studies on the mechanisms of hyperthermia- and TNF-α-induced apoptosis.January 2002 (has links)
by Yuen Wai Fan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 211-232). / Abstracts in English and Chinese. / Acknowledgements --- p.i / List of Publications and Abstracts --- p.ii / Abbreviations --- p.iv / Abstract --- p.xi / Abstract in Chinese --- p.xiv / List of Figures --- p.xvii / List of Tables --- p.xxiii / Contents --- p.xxiv / Chapter Chapter 1. --- General Introduction --- p.1 / Chapter 1.1 --- Hyperthermia --- p.2 / Chapter 1.1.1 --- History of Hyperthermia --- p.2 / Chapter 1.1.2 --- Biological Functions of Hyperthermia --- p.3 / Chapter 1.1.3 --- Clinical Application of Hyperthermia --- p.4 / Chapter 1.1.3.1 --- Whole-body Hyperthermia --- p.4 / Chapter 1.1.3.2 --- Regional Hyperthermia --- p.4 / Chapter 1.1.3.3 --- Local Hyperthermia --- p.5 / Chapter 1.1.4 --- Combination Therapy --- p.5 / Chapter 1.1.4.1 --- Combined treatment with Hyperthermia and Radiotherapy --- p.6 / Chapter 1.1.4.2 --- Combined treatment with Hyperthermia and Chemotherapy --- p.6 / Chapter 1.2 --- Tumour Necrosis Factor --- p.9 / Chapter 1.2.1 --- History of Tumour Necrosis Factor --- p.9 / Chapter 1.2.2 --- Sources of TNF-α and TNF-β --- p.9 / Chapter 1.2.3 --- Biological Roles of TNF --- p.10 / Chapter 1.2.3.1 --- Receptors of TNF-α --- p.11 / Chapter 1.2.4 --- Signaling Pathway of TNF --- p.12 / Chapter 1.2.4.1 --- Activation of Death Domain --- p.12 / Chapter 1.2.4.2 --- Activation of Sphingomyelin Pathway --- p.13 / Chapter 1.2.4.3 --- Activation of NF-kB pathway --- p.13 / Chapter 1.3 --- Types of Cell Death: Necrosis and Apoptosis --- p.16 / Chapter 1.3.1 --- Necrosis --- p.16 / Chapter 1.3.2 --- Apoptosis --- p.16 / Chapter 1.4 --- Signaling Pathway in Apoptosis --- p.19 / Chapter 1.4.1 --- Factors Involved in Apoptotic Pathway --- p.19 / Chapter 1.4.1.1 --- Caspases --- p.19 / Chapter 1.4.1.2 --- Death Substrates --- p.20 / Chapter 1.4.1.3 --- Bcl-2 Protein Family --- p.21 / Chapter 1.4.1.4 --- Role of Mitochondria --- p.23 / Chapter 1.5 --- Objectives of the Project --- p.26 / Chapter Chapter 2. --- Materials and Methods --- p.28 / Chapter 2.1 --- Materials --- p.29 / Chapter 2.1.1 --- Culture of Cells --- p.34 / Chapter 2.1.1.1 --- "TNF-α Sensitive Cell Line, L929" --- p.34 / Chapter 2.1.1.2 --- "TNF-α Resistance Cell Line, L929-11E" --- p.34 / Chapter 2.1.1.3 --- Preservation of Cells --- p.35 / Chapter 2.1.2 --- Culture Media --- p.36 / Chapter 2.1.2.1 --- RPMI 1640 (Phenol Red Medium) --- p.36 / Chapter 2.1.2.2 --- RPMI 1640 (Phenol Red-Free Medium) --- p.36 / Chapter 2.1.3 --- Buffers and Reagents --- p.37 / Chapter 2.1.3.1 --- Preparation of Buffers --- p.37 / Chapter 2.1.3.2 --- Buffer for Common Use --- p.37 / Chapter 2.1.3.3 --- Reagents for Annexin-V-FITC/PI assay --- p.37 / Chapter 2.1.3.4 --- Reagents for Cytotoxicity Assay --- p.37 / Chapter 2.1.3.5 --- Reagents for Molecular Biology Work --- p.38 / Chapter 2.1.3.6 --- Reagents for Western Blotting Analysis --- p.38 / Chapter 2.1.4 --- Chemicals --- p.40 / Chapter 2.1.4.1 --- Recombinant Murine TNF-α --- p.40 / Chapter 2.1.4.2 --- Dye for Cytotoxicity Assay --- p.41 / Chapter 2.1.4.3 --- Fluorescence Dyes --- p.41 / Chapter 2.1.4.4 --- Chemicals Related to Mitochondrial Studies --- p.41 / Chapter 2.1.4.5 --- Inhibitors of Caspases --- p.42 / Chapter 2.1.4.6 --- Antibodies for Western Blotting --- p.42 / Chapter 2.1.4.7 --- Other Chemicals --- p.43 / Chapter 2.2 --- Methods --- p.44 / Chapter 2.2.1 --- Treatment with TNF-α --- p.44 / Chapter 2.2.2 --- Treatment with Hyperthermia --- p.44 / Chapter 2.2.3 --- In vitro Cell Cytotoxicity Assay --- p.45 / Chapter 2.2.4 --- Flow Cytometry --- p.46 / Chapter 2.2.4.1 --- Introduction --- p.46 / Chapter 2.2.4.2 --- Analysis by FCM --- p.48 / Chapter 2.2.4.3 --- Determination of Apoptotic and Late Apoptotic/Necrotic Cells with Annexin-V-FITC/PI Cytometric Analysis --- p.50 / Chapter 2.2.4.4 --- Determination of Mitochondrial Membrane Potential (ΔΨm) --- p.51 / Chapter 2.2.4.5 --- Determination of Hydrogen Peroxide (H202) Release --- p.52 / Chapter 2.2.4.6 --- Determination of Intracellular Free Calcium ([Ca2+]i) Level --- p.52 / Chapter 2.2.4.7 --- Determination of the Relationship of ΔΨm and [Ca2+]i Level --- p.53 / Chapter 2.2.5 --- Western Blotting Analysis --- p.53 / Chapter 2.2.5.1 --- Preparation of Proteins from Cells --- p.53 / Chapter 2.2.5.2 --- SDS Polyacrylamide Gel Electophoresis (SDS- PAGE) --- p.56 / Chapter 2.2.5.3 --- Electroblotting of Proteins --- p.57 / Chapter 2.2.5.4 --- Probing Antibodies for Proteins --- p.57 / Chapter 2.2.5.5 --- Enhanced Chemiluminescence (ECL) assay --- p.58 / Chapter 2.2.6 --- Reverse Transcriptase Polymerase Chain Reaction --- p.58 / Chapter 2.2.6.1 --- Extraction of RNA by Trizol Reagent --- p.59 / Chapter 2.2.6.2 --- Determination of the Amount of RNA --- p.60 / Chapter 2.2.6.3 --- Agarose Gel Electrophoresis --- p.60 / Chapter 2.2.6.4 --- Reverse Transcription --- p.63 / Chapter 2.2.6.5 --- Polymerase Chain Reaction (PCR) --- p.63 / Chapter 2.2.6.6 --- Design of Primers for Different Genes --- p.64 / Chapter 2.2.6.7 --- Determination of the Number of Cycles in PCR for Different Genes --- p.67 / Chapter 2.2.7 --- Caspase Fluorescent Assay --- p.67 / Chapter 2.2.7.1 --- Caspase-3 or ´ؤ8 Assay --- p.67 / Chapter Chapter 3. --- Results --- p.59 / Chapter 3.1 --- Studies of the Characteristics of L929 and L929-11E cells --- p.70 / Chapter 3.1.1 --- Determination of the Growth Curve of L929 and L929-11E Cells --- p.70 / Chapter 3.2 --- Studies on the Effect of TNF-α on L929 and L929-11E Cells --- p.73 / Chapter 3.2.1 --- TNF-α Induced Cell Death in L929 Cells but not in L929- 11E Cells --- p.73 / Chapter 3.2.2 --- TNF-α Induced Apoptosis in a Time-dependent Manner in L929Cells but not in L929-11E Cells --- p.80 / Chapter 3.2.3 --- TNF-α Induced Mitochondrial Membrane Depolarization in a Time-dependent Manner in L929 Cells but notin L929-11E Cells --- p.87 / Chapter 3.2.4 --- TNF-α Induced Cytochrome c Release in a Time- dependent Manner in L929 Cells but not in L929-11E Cells --- p.92 / Chapter 3.3 --- Effect of Hyperthermia on L929 and L929-11E Cells --- p.96 / Chapter 3.3.1 --- Introduction --- p.95 / Chapter 3.3.2 --- Hyperthermia Induced Apoptosis in L929 and L929-11E Cells --- p.96 / Chapter 3.3.3 --- Effect of Hyperthermia on Mitochondrial Membrane Depolarization --- p.100 / Chapter 3.3.4 --- Hyperthermia Induced Cyto c Release in a Time-dependent Manner in L929 and L929-11E Cells --- p.105 / Chapter 3.4 --- Relationship of Hyperthermia and TNF-α with PTP in L929 Cells --- p.107 / Chapter 3.5 --- Effect of TNF-α and Hyperthermia on the Level of Hydrogen Peroxide (H202) in L929 and L929-11E Cells --- p.114 / Chapter 3.5.1 --- Introduction --- p.114 / Chapter 3.5.2 --- TNF-α Enhanced the Level of H202 in L929 cells but not in L929-11E Cells --- p.115 / Chapter 3.5.3 --- Hyperthermia Enhanced the Level of H202 in L929 and L929-11E cells --- p.117 / Chapter 3.6 --- Effect of TNF-α and Hyperthermia on the Level of Intracellular Calcium in L929 and L929-11E Cells --- p.122 / Chapter 3.6.1 --- Increase in the Intracellular Calcium Level Induced by TNF-α Was Related to the Mitochondrial Membrane Depolarization in L929 Cells but not in L929-11E Cells --- p.122 / Chapter 3.6.2 --- Hyperthermia Increased the Level of [Ca2+]i in L929 and L929-11E Cells in a Time-dependent Manner --- p.124 / Chapter 3.7 --- Effect of Combined Hyperthermia and TNF-α Treatment on the Induction of Apoptosis in L929 and L929-1 1E Cells --- p.129 / Chapter 3.7.1 --- Combined Treatment with Hyperthermia and TNF- α Induced Apoptosis in Both L929 and L929-11E cells --- p.129 / Chapter 3.7.2 --- Hyperthermia and Its Combined Treatment with TNF-α Induced Mitochondrial Membrane Depolarization in L929 and L929-11E Cells --- p.135 / Chapter 3.8 --- Investigation of the Downstream Apoptotic Pathway in L929 and L929-11E Cells Upon Hyperthermia and TNF-a treatment --- p.142 / Chapter 3.8.1 --- Introduction --- p.142 / Chapter 3.8.2 --- Effect ofTNF-α and Hyperthermia on p53 Expression --- p.142 / Chapter 3.8.3 --- Effect of Hyperthermia and TNF-α on PARP --- p.146 / Chapter 3.8.4 --- Effect of Hyperthermia and TNF-α on Caspase-3 Activity --- p.149 / Chapter 3.8.5 --- Effect of Hyperthermia and TNF-α on Bid protein --- p.158 / Chapter 3.8.6 --- Effect of Hyperthermia and TNF-α on Caspase-8 Activity --- p.165 / Chapter 3.8.7 --- Effect ofTNF-α on TNFR1 Expression --- p.169 / Chapter Chapter 4. --- Discussion / Chapter 4.1 --- TNF-α Induced Apoptosis and Changed the Mitochondrial Activities in L929 Cells --- p.176 / Chapter 4.2 --- L929-11E cells Possessed Resistance Towards TNF-α --- p.187 / Chapter 4.3 --- Hyperthermia Triggered Apoptosis and Changed Mitochondrial Activities in L929 and L929-11E cells --- p.190 / Chapter 4.4 --- Combined hyperthermia and TNF-α treatment induced cell death and changed mitochondria activities in L929 and L929-11E cells --- p.195 / Chapter 4.5 --- Reversal of the TNF-α resistance and Enhancement of Sensitivity Towards Hyperthermia in L929-11E cells --- p.197 / Chapter 4.6 --- Proposed Pathway in the TNF-α- and Hyperthermia-mediated Apoptosis --- p.200 / Chapter 4.7 --- Application of TNF-α and Hyperthermia on Clinical Cancer Treatment --- p.203 / Chapter Chapter 5. --- Future Perspective of the Project --- p.206 / References --- p.210
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Avaliação da função tímica em pacientes com Síndrome de DiGeorge / Assessment of thymic function in patients with DiGeorge SyndromeAngela Bueno Ferraz Fomin 11 March 2010 (has links)
Entre as síndromes de deleção do cromossomo 22q.11, a Síndrome de DiGeorge foi descrita em 1967 como uma imunodeficiência primária caracterizada por: malformações cardíacas, hipoparatireoidismo e ausência de timo. A incidência estimada é de 1: 3000 nascidos vivos e apesar disto seu reconhecimento ainda apresenta dificuldades devido à grande variabilidade fenotípica e diferentes nomenclaturas. Para o diagnóstico é necessário a presença do número de células T circulantes diminuído ou normal, número de células B circulantes normais e níveis séricos de imunoglobulinas diminuídos ou normais associado com os seguintes achados: hipoparatireoidismo, malformações cardíacas conotruncais, dismorfismo facial e detecção da deleção do cromossomo 22q.11. Os pacientes com Síndrome de DiGeorge apresentam graus variados de comprometimento tímico e há a necessidade de avaliação da função tímica objetiva e eficaz para este grupo de pacientes. Recentemente, a mensuração do TREC tem sido considerada adequada para avaliar a função tímica. O objetivo deste estudo foi avaliar a função tímica em pacientes com esta síndrome através de dados clínicos e laboratoriais associados à mensuração do TREC em células mononucleares periféricas. Os objetivos secundários foram descrever as características fenotípicas, as alterações imunológicas incluindo a quantificação de subpopulações de linfócitos T e sua ativação. A quantificação do TREC foi feita através de PCR quantitativo em tempo real e as subpopulações de linfócitos T e dos marcadores de ativação CD28+ e HLA-DR+, através de citometria de fluxo. Nesta casuística foram incluídos 14 pacientes, oito masculinos, com idade entre 8m a 18a11m. Todos os pacientes preencheram os critérios diagnósticos e em dois não foi detectada a deleção do 22q11.2. O achado mais freqüente foi o acometimento cardíaco em 12 pacientes, prevalecendo a tetralogia de Fallot. O dismorfismo facial foi observado em 11 pacientes, sendo as alterações orofaciais as mais comuns. Hipocalcemia esteve presente em cinco pacientes e em um deles havia associação com hipotireoidismo neonatal. Depressão foi observada em dois pacientes e atualmente nenhum paciente apresenta quadro de infecção de repetição. À avaliação da imunidade humoral, detectou-se cinco pacientes com concentrações séricas de IgM abaixo dos valores normais para a idade e na avaliação da anticorpogênese somente três pacientes responderam com títulos protetores para a o esquema vacinal completo para hepatite B e quatro para sarampo. A quantificação do número de TREC realizada em 12 pacientes mostrou-se reduzida em relação aos controles com uma significância estatística (p = 0,002). O número de linfócitos totais estava dentro dos valores normais, mas, os valores de CD3+ estavam diminuídos em nove, CD4+ em um e CD8+ em cinco pacientes. Observou-se maior expressão de marcadores de ativação linfocitária no grupo de pacientes que nos controles (p = 0, 002). Conclusão: Este estudo revelou que os pacientes avaliados apresentaram alteração tanto da imunidade celular como humoral em especial em relação à anticorpogênese pós vacinal e redução da subpopulação de linfócitos T. A reduzida quantidade de TREC em relação aos controles pode indicar uma disfunção tímica embora tenha sido observado normalidade linfocitária nestes pacientes / Among the syndromes of 22q.11 deletion, the DiGeorge Syndrome was first described in 1967 as a primary immunodeficiency characterized by: heart defects, hypoparathyroidism and absence of thymus. The estimated incidence is 1: 3000 live births and despite this, its recognition still presents difficulties due to large variability and different nomenclatures. For the diagnosis it is necessary the presence of the decreased or normal number of circulating T cells, normal number of circulating B cells and decreased or normal levels serum of immunoglobulins associated with the following findings: hypoparathyroidism, conotruncal heart defects, facial dimorphism and detection of 22q.11 deletion. Patients with DiGeorge syndrome have varying degrees of thymic commitment and there is a necessity for an objectively and effectively evaluation of thymic function to this group of patients. Recently, the measurement of TREC has been considered adequate to evaluate the thymic function. The aim of this study was to evaluate the thymic function in patients with this syndrome through clinical and laboratory data associated with the measurement of TREC in peripheral blood mononuclear cells. The secondary objectives were to describe the phenotypic characteristics, immune disorders including quantification of subpopulations of T lymphocytes and their activation. Quantification of TREC was performed by quantitative PCR in real time and the subpopulations of T lymphocytes and activation markers CD28+ and HLA-DR+, by flow cytometry. In this case series included 14 patients, eight male, aged 8m to 18y11m. All patients met the diagnostic criteria and two did not detect the 22q11.2 deletion. The most common finding was cardiac involvement in 12 patients, with prevalence of tetralogy of Fallot. The facial dimorphism was observed in 11 patients with orofacial changes being the most common. Hypocalcaemia was present in five patients and one of them was associated with neonatal hypothyroidism. Depression was observed in two patients and now, no patient presents recurrent infections. In the humoral immunity, we have found five patients with serum IgM below normal for age and only three patients responded with protective levels of antibodies to the complete vaccine schedule for hepatitis B and four for measles. The measurement of the number of TREC was performed in 12 patients and it was reduced compared to controls with a statistical significance (p = 0, 002). The total number of lymphocytes were within the normal range, but the values of CD3+ were decreased in nine, CD4+ in one and CD8+ in five patients. It was found a higher expression of markers of lymphocyte activation in the group of patients than in controls (p = 0, 002). Conclusion: This study revealed that in the patients studied both humoral and cellular immunity was compromised, in particular in relation to vaccinal response and reduction the subpopulation of T lymphocytes. The reduced amount of TREC when compared to controls may indicate a thymic dysfunction despite the normal lymphocytes in these patients
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Altered immune function associated with neurophysiologic abnormalities and executive function deficits in children with autism spectrum disorders. / CUHK electronic theses & dissertations collectionJanuary 2010 (has links)
In study one, the executive functioning of 19 high-functioning (HFA) and 19 low-functioning (LFA) children with ASD were compared to 28 children with normal development using a battery of neuropsychological tests. Results not only confirmed previous knowledge that children with ASD had significant executive dysfunctions compared with children with normal development, but also extended it to show that LFA children were significantly more impaired than HFA children. Study two built on this knowledge and examined whether immunological abnormalities are associated with the differential executive dysfunctions in 18 HFA and 19 LFA children. Results indicated that LFA children showed greater executive dysfunctions as well as higher levels of total lymphocyte, T lymphocyte and suppressor/cytotoxic T lymphocyte levels than HFA children. In addition, executive dysfunctions were significantly associated with the three lymphocyte levels, lending support to the notion that immunological factors may play a role in the cognitive dysfunctions in individuals with ASD. Study three further examined whether the differential executive dysfunctions and immunologic levels in LFA and HFA children are associated with their neural connectivity. Results on 17 HFA and 14 LFA children showed that LFA children had significantly elevated theta coherence in the anterior network, as well as at the left intra-hemispheric and right-to-left inter-hemisphere connections than HFA children. LFA children also had significantly elevated immunologic level specifically in suppressor/cytotoxic T lymphocytes. Furthermore, the executive dysfunctions, disordered neural connectivity, and abnormal immunologic levels were found to be associated. / Recent evidence suggests that deficient executive functions are fundamental to the cognitive deficits in Autism spectrum disorders (ASD). It has been suggested that individuals with ASD have disrupted neural connectivity including that in the frontal lobes that mediate executive functions. With reports of immunologic abnormalities in children with ASD, it is plausible that such abnormalities disrupt the neural connectivity in the brains of individuals with ASD. There is, however, relatively little empirical evidence to support the notion. This dissertation reports on three studies to examine whether the executive dysfunction in children with ASD is associated with their immunologic abnormalities and disordered neural connectivity. / These findings have provided some initial evidence to support the notion that immunologic factors may play a role in causing neuronal damage in the anterior region of the brains of children with ASD, which is manifested in their disordered neural connectivity of that region, and their executive dysfunctions mediated by that same region. / Han, Yvonne Ming Yee. / Adviser: Agnes Chan. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 103-132). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
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