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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.
11

Características clínicas e genéticas de pacientes brasileiros com a Síndrome de Wiskott-Aldrich / Clinical and genetic characteristics of Brazilian patients with Wiskott-Aldrich syndrome

Castro, Maria Eduarda Pontes Cunha de 04 June 2018 (has links)
Introdução: A síndrome de Wiskott-Aldrich (SWA) é uma imunodeficiência primária rara ligada ao X caracterizada pela presença de eczema, trombocitopenia com ou sem microplaquetas e infecções recorrentes. Mais de 300 tipos de mutações associadas com o gene WAS foram descritas, incluindo oito hotspots. A diversidade destas mutações pode levar ao aparecimento de grande variabilidade nas apresentações clínicas, o que dificulta a previsão da evolução da doença baseada apenas nas manifestações iniciais. Além disso, há escassez de informações sobre a população brasileira. Objetivos: Descrever as características clínicas e genéticas de pacientes brasileiros com diagnóstico clínico de SWA. Resultados: Dezoito pacientes foram avaliados. Dezessete pacientes apresentaram os primeiros sintomas no primeiro ano de idade. Idade média para o início dos sintomas foi de 4,5 meses e média de tempo para o diagnóstico foi de 31,2 meses. Três pacientes (16,3%) foram diagnosticados após 10 anos de início dos sintomas. Dezessete pacientes (94,5%) apresentaram eczema. Os níveis plaquetários variaram entre 1.000 e 65.000/mm3 e nove pacientes (50%) apresentaram microtrombocitopenia. Dois pacientes (11,1%) apresentaram macroplaquetas. Dezesseis pacientes (88,9%) tiveram eventos hemorrágicos ao longo de suas vidas, especialmente sangramentos intestinais, urinários e petéquias. Em relação às manifestações infecciosas, otite média aguda foi a infecção mais frequente, relatada por 13 pacientes (72,2%), seguido por infecções cutâneas (66,7%). Três pacientes(16,6%) apresentaram manifestações autoimunes, incluindo nefropatia por IgA, trombose isquêmica e vasculite. A maioria dos pacientes (55,5%) não apresentou alterações nos níveis IgG. Níveis elevados de IgA só foram observados em 4 pacientes (23,5%). Redução dos níveis IgM foi observada em 7 pacientes (38,9%). Os pacientes foram classificados de acordo com um escore clínico previamente descrito. A maioria apresentou pontuações de 3 (33,3%) e 4 (27,8%). Quatro pacientes (22,2%) foram classificados com pontuação 5 devido às manifestações autoimunes ou neoplasias. Em relação à análise genética, foram encontradas mutações em 10 pacientes (55,5%). Apenas três das mutações encontradas neste estudo foram descritas previamente. Conclusão: As características clínicas dos pacientes brasileiros foram semelhantes às características observadas em outras populações, porém a análise genética revelou mutações ainda não descritas. / Introduction: Wiskott-Aldrich syndrome (WAS) is a rare X-linked primary immunodeficiency characterized by eczema, thrombocytopenia with or no small sized platelets and recurrent infections. More than 300 types of mutations associated with the WAS gene have been described, including eight hotspots. The diversity of these mutations can lead to the appearance of great variation in the clinical presentations, which makes it difficult to predict the evolution of the disease based only on the initial manifestations. Furthermore, there is paucity of information on WAS from the Brazilian population. Objectives: To describe the clinical and genetic characteristics of Brazilian patients with clinical diagnose of WAS. Results: Eighteen patients were evaluated. Seventeen patients presented first symptoms within first year of age. Mean age for initiating symptoms was 4,5 months and mean time for diagnosis was 31,2 months. Three patients (16.6%) were diagnosed after 10 years of initiating symptoms. Seventeen patients (94.5%) had eczema. The platelet levels ranged from 1,000 to 65,000/mm3 and nine patients (50%) presented microthrombocytopenia. Two patients (11.1%) had macroplatelets. Sixteen patients (88.9%) had hemorrhagic events throughout their lives, especially intestinal, urinary and petechial bleedings. In relation to infectious manifestations, acute media otitis was the most frequent infection, reported by 13 patients (72.2%), followed by skin infections (66.7%). Three patients (16.6%) had autoimmune manifestations including IgA nephropathy,ischemic stroke and vasculitis. Most patients (55.5%) did not present alterations in IgG levels. Twelve patients (70.6%) did not present alterations in IgA levels and elevated levels of IgA were only observed in 4 patients (23.5%). Reduction of IgM levels was observed in 7 patients (38.9%). Patients were classified according to a previously described clinical score. Most patients presented scores of 3 (33.3%) and 4 (27.8%). Four patients (22.2%) were classified with score 5 due to autoimmune or neoplastic manifestations. Regarding genetic analysis, mutations were found in 10 patients (55.5%). Only three of mutations found in this study were previously described. Conclusion: Clinical characteristics of Brazilian patients were similar to medical features observed in other populations, however genetic analysis showed undescribed mutations yet
12

Anticorpos séricos anti Escherichia coli enterohemorrágica (EHEC) em adultos saudáveis da Grande São Paulo / Seric antibodies anti-hemorrhagic Escherichia coli (EHEC) in healthy Brazilian adults

Quintanilla, Lucy Beatriz Zapata 03 March 2005 (has links)
As gastroenterites ainda são um importante problema de saúde pública nos países em desenvolvimento e as Escherichia colí são as principais causas de diarréias. Adultos brasileiros apresentam anticorpos reativos com E. colí enteropatogênica (EPEC), que apresenta muitas semelhanças com E. colí enterohemorágica (EHEC) e pode ser responsável por complicações como a síndrome hemolítica urêmica e a colite hemorrágica. Ambas as bactérias apresentam um mecanismo patogênico comum: a formação da lesão \"attaching and effacing\" nos microvilus dos enterócitos, mediadas por fatores de virulência, como Intimina, Tir e as Esps. Os lipopolissacarídeos (LPS) são componentes da membrana externa das bactérias gram-negativas, incluindo E. colí. A infecção por EHEC 0157 resulta na produção de anticorpos séricos antiLPS 0157, que geralmente são indicativos de infecção recente. Neste trabalho, nós investigamos a presença de anticorpos séricos IgG e IgM anti-EHEC 0157:H7, EHEC 0111:H- e EPEC 0111:H- em adultos brasileiros, da Grande São Paulo. Amostras de soro foram coletadas de 200 adultos saudáveis, doadores de sangue, e um pool foi formado com 100 amostras. Anticorpos foram determinados em 100 amostras individuais por ELlSA com bactérias íntegras e anti-LPS para a determinação de anticorpos específicos anti-LPS 0111 e 0157 com o \"pool\" de soro como controle, em relação às concentrações de IgG e IgM totais determinadas simultaneamente. Os resultados foram submetidos a análise estatística. O repertório de anticorpos IgG e IgM para as três bactérias foi investigado por \"immunoblotting\" (18). A presença de anticorpos anti-bacterianos e anti-LPS foi confirmada. Existe uma correlação positiva entre os anticorpos reativos com as três bactérias, e entre os anticorpos anti-bactéria e anti-LPS. As concentrações de IgM anti-LPSs foi mais alta que IgG, o que está de acordo com o mecanismo imune esperado para um antígeno timo-independente. As concentrações de anti-LPS 0157 foram altas, apesar da baixa freqüência da bactéria 0157 em nosso meio. Os ensaios de 18 mostraram anticorpos reativos com bandas antigênicas sugestivas de fatores de virulência. A origem destes em nossa população poderia ser o contato com bactérias da microbiota ou do ambiente, de animais ou alimentos. Alternativamente, nossa população pode estar exposta à EHEC mais freqüentemente do que imaginado até agora. / Gastroenteritis is still an important public health problem in developing countries and Escherichia coli are frequent agents of diarrhea. Brazilian adults present antibodies reactive with the principal virulence factors of enteropathogenic E. coli (EPEC), which have many genetic and antigenic similarities with enterohemorrhagic E. coli (EHEC), that may be responsible for complications following diarrhea, as haemolytic uremic syndrome (HUS) and hemorrhagic colitis (HC). Both bacteria present a common pathogenic mechanism, with the formation of “attaching and effacing" lesion in microvilis’ enterocytes, mediated by virulence factors codified by the patogenicity island LEE, as Intimin, Tir e Esps. Lipopolysaccharides (LPS) are components of outer membrane and important virulence factors of Gram-negative bacteria including E. coli. The infection with EHEC O157 results in the production of serum antibodies to the O157 LPS antigens, and usually they are indicators of recent infection. In this work we investigated IgG and IgM serum antibodies reactive with EHEC O157:H7, EHEC O111:H- and EPEC O111:H- antigens in healthy Brazilian adults, living in São Paulo. Serum samples were collected from 200 healthy adults (blood donors) and a pool was formed with 100 samples. The antibody levels were determined by ELISA for 100 individual serum samples by means of a whole cell ELISA with the three bacteria and an anti-LPS ELISA for the determination of the concentrations of specific antibodies anti-LPS O111 and O157, using the serum pool as control, in relation to the total IgG and IgM concentrations determined simultaneously. The results were submitted to statistical analysis. The repertoire of IgG and IgM antibodies to the three bacteria was investigated by immunoblotting (IB). The presence of anti-bacterial and anti-LPS seric antibodies was confirmed. There is a positive correlation between the titers of antibodies reactive with the three bacteria and between anti-bacteria and anti-LPS antibodies. The concentrations of IgM anti-LPSs were significantly higher than IgG, which is in accordance with the immune mechanism expected to a thymus-independent antigen. Surprisingly the concentrations of anti-LPS O157 were high taking into account the low frequency of O157 bacteria isolation in our country. The IB assays showed the presence of antibodies, mainly IgG, reactive with many antigenic bands suggestive of virulence factors. The origin of anti-EHEC antibodies in our population could be the contact with microbiota or environment bacteria, and animal or human E. coli strains, pathogenic or not. Alternatively, our people may be exposed to EHEC more frequently than previously thought.
13

Características clínicas e genéticas de pacientes brasileiros com a Síndrome de Wiskott-Aldrich / Clinical and genetic characteristics of Brazilian patients with Wiskott-Aldrich syndrome

Maria Eduarda Pontes Cunha de Castro 04 June 2018 (has links)
Introdução: A síndrome de Wiskott-Aldrich (SWA) é uma imunodeficiência primária rara ligada ao X caracterizada pela presença de eczema, trombocitopenia com ou sem microplaquetas e infecções recorrentes. Mais de 300 tipos de mutações associadas com o gene WAS foram descritas, incluindo oito hotspots. A diversidade destas mutações pode levar ao aparecimento de grande variabilidade nas apresentações clínicas, o que dificulta a previsão da evolução da doença baseada apenas nas manifestações iniciais. Além disso, há escassez de informações sobre a população brasileira. Objetivos: Descrever as características clínicas e genéticas de pacientes brasileiros com diagnóstico clínico de SWA. Resultados: Dezoito pacientes foram avaliados. Dezessete pacientes apresentaram os primeiros sintomas no primeiro ano de idade. Idade média para o início dos sintomas foi de 4,5 meses e média de tempo para o diagnóstico foi de 31,2 meses. Três pacientes (16,3%) foram diagnosticados após 10 anos de início dos sintomas. Dezessete pacientes (94,5%) apresentaram eczema. Os níveis plaquetários variaram entre 1.000 e 65.000/mm3 e nove pacientes (50%) apresentaram microtrombocitopenia. Dois pacientes (11,1%) apresentaram macroplaquetas. Dezesseis pacientes (88,9%) tiveram eventos hemorrágicos ao longo de suas vidas, especialmente sangramentos intestinais, urinários e petéquias. Em relação às manifestações infecciosas, otite média aguda foi a infecção mais frequente, relatada por 13 pacientes (72,2%), seguido por infecções cutâneas (66,7%). Três pacientes(16,6%) apresentaram manifestações autoimunes, incluindo nefropatia por IgA, trombose isquêmica e vasculite. A maioria dos pacientes (55,5%) não apresentou alterações nos níveis IgG. Níveis elevados de IgA só foram observados em 4 pacientes (23,5%). Redução dos níveis IgM foi observada em 7 pacientes (38,9%). Os pacientes foram classificados de acordo com um escore clínico previamente descrito. A maioria apresentou pontuações de 3 (33,3%) e 4 (27,8%). Quatro pacientes (22,2%) foram classificados com pontuação 5 devido às manifestações autoimunes ou neoplasias. Em relação à análise genética, foram encontradas mutações em 10 pacientes (55,5%). Apenas três das mutações encontradas neste estudo foram descritas previamente. Conclusão: As características clínicas dos pacientes brasileiros foram semelhantes às características observadas em outras populações, porém a análise genética revelou mutações ainda não descritas. / Introduction: Wiskott-Aldrich syndrome (WAS) is a rare X-linked primary immunodeficiency characterized by eczema, thrombocytopenia with or no small sized platelets and recurrent infections. More than 300 types of mutations associated with the WAS gene have been described, including eight hotspots. The diversity of these mutations can lead to the appearance of great variation in the clinical presentations, which makes it difficult to predict the evolution of the disease based only on the initial manifestations. Furthermore, there is paucity of information on WAS from the Brazilian population. Objectives: To describe the clinical and genetic characteristics of Brazilian patients with clinical diagnose of WAS. Results: Eighteen patients were evaluated. Seventeen patients presented first symptoms within first year of age. Mean age for initiating symptoms was 4,5 months and mean time for diagnosis was 31,2 months. Three patients (16.6%) were diagnosed after 10 years of initiating symptoms. Seventeen patients (94.5%) had eczema. The platelet levels ranged from 1,000 to 65,000/mm3 and nine patients (50%) presented microthrombocytopenia. Two patients (11.1%) had macroplatelets. Sixteen patients (88.9%) had hemorrhagic events throughout their lives, especially intestinal, urinary and petechial bleedings. In relation to infectious manifestations, acute media otitis was the most frequent infection, reported by 13 patients (72.2%), followed by skin infections (66.7%). Three patients (16.6%) had autoimmune manifestations including IgA nephropathy,ischemic stroke and vasculitis. Most patients (55.5%) did not present alterations in IgG levels. Twelve patients (70.6%) did not present alterations in IgA levels and elevated levels of IgA were only observed in 4 patients (23.5%). Reduction of IgM levels was observed in 7 patients (38.9%). Patients were classified according to a previously described clinical score. Most patients presented scores of 3 (33.3%) and 4 (27.8%). Four patients (22.2%) were classified with score 5 due to autoimmune or neoplastic manifestations. Regarding genetic analysis, mutations were found in 10 patients (55.5%). Only three of mutations found in this study were previously described. Conclusion: Clinical characteristics of Brazilian patients were similar to medical features observed in other populations, however genetic analysis showed undescribed mutations yet
14

Genetic Engineering of T Lymphocytes for Cancer Immunotherapy : Optimisation of Gene Transfer

Lindqvist, Camilla January 2006 (has links)
<p>T lymphocytes can be rendered specific against a wide range of antigens by the genetic transfer of a chimeric receptor, a fusion between the antigen-binding domain of an antibody and the signalling domain of a T cell receptor. The use of such chimeric T lymphocytes has shown promising results for cancer therapy. Previous experiments in our laboratory have shown low rates of gene transfer using retroviral vectors. In this study, investigations have been done to increase the number of genetically modified cells. Different enhancers such as PLL and polybrene have previously been used in combination with retroviral transduction. The optimal retroviral protocol in this study showed to be the use of retrovectors produced with twice the normal concentration of the plasmids encoding env and gag-pol rather than the use of the enhancers. A 6-day pre stimulation of T lymphocytes prior transduction together with a centrifugation step increased the rate of modified cells even further. Alternative approaches of gene transfer were also investigated, including plasmid transfection and adenoviral transduction. While transfection protocols yielded low numbers of modified cells, adenoviral vectors showed the highest rate of gene transfer.</p> / <p>Cancer är den sjukdom som idag, efter hjärt-kärl-sjukdomar, kräver flest dödsfall i i-länder. Som en alternativ behandlingsmetod mot cancer pågår just nu forskning om genetiskt förbättrade immunceller, s.k. chimära T lymfocyter, skulle kunna användas för att döda tumörceller. De chimära cellerna är utrustade med en konstgjord receptor som är en fusion av en antikropp och en signalkedja. Det gör att cellerna kan riktas mot ett brett urval av cancertyper. Att få cellerna att ta upp generna som behövs för den konstgjorda receptorn har visats sig vara problematiskt. Den här studien har därför som mål att förbättra cellernas förmåga att ta upp gener. För detta har vi använt oss av retrovirus- och adenovirus-system tillsammans med försök att få cellerna att spontant ta upp generna, sk. plasmid-transfektion. Studien har visat att de båda virussystemen ger högst antal modifierade celler. Olika substanser som tidigare har visat sig förhöja graden av gentillförsel har testats, men vår studie har visat att tillverkningen av virusvektorerna har större påverkan på resultaten än någon av de olika hjälpmedlen.</p>
15

Methods for identification and diagnosis of amyloidosis

Dadgar, Ashraf January 2006 (has links)
<p>The amyloidoses are biochemically heterogeneous diseases with patholophysiologic deposits of various proteins. Amyloid deposits can occur either localized to one organ or tissue or as part of a systemic disease with deposits in many different tissue. The clinical course, prognosis and therapy are different for each type of amyloidosis and therefore a type specific diagnosis is demanded as early as possible. We describe a method for typing of the most common systemic amyloidoses based on Western blot analysis combined with specific</p><p>in- house antibodies, using subcutaneous fat biopsies. We found that the method is reliable and easy to perform and the tissue sample needed is obtained by minor surgery.</p><p>In the aortic intima amyloid deposits are often associated with atherosclerosis plaques. In our study we also investigated the prevalence of intimal amyloid from 10 patients age 58-94, amyloid deposits were present in 50% of the cases.</p> / <p>Amyloidos är ett sjukdomstillstånd där proteiner som normalt är lösliga i kroppen felveckas och formar långa olösliga fibriller som ansamlas i vävnader och organ såsom t.ex. hjärta, hjärna och lever. Det finns cirka 25 proteiner som kan ge upphov till amyloidos. Man kan skilja på två huvudgrupper av amyloidos, systemisk och lokaliserad. Vid lokal amyloidos kan inlagringar förekomma i specifika vävnader vid framför allt vissa åldersberoende sjukdomar som t.ex. Alzheimers sjukdom. Vid systemisk amyloidos förekommer inlagringar i praktiskt taget alla vävnader. Symtomatologin vid systemisk amyloidos är variabel och sjukdomsbilden kan vara svårtolkad men tidig och specifik diagnostik ger möjlighet till riktad terapi mot den bakomliggande sjukdomen. Syftet med denna studie var att utvärdera en Western blot metod som använts för typning av vanligaste formerna av systemisk amyloidos. De slutsatser som nåtts är att denna metod är snabbt, pålitligt och enkel att utföra. Diagnos erhölls med finnålsbiopsi av bukfettvävnad som är enkel, snabb och billig metod med liten risk för patienternas hälsa. Vi lyckades också med hjälp av immunhistokemisk infärgning titta på prevalens av amyloid i aortas intima.</p>
16

Formation of Composite Islet Grafts : A novel strategy to promote islet survival and revascularization

Johansson, Ulrika January 2009 (has links)
The islets of Langerhans are small and delicate spheroid organs scattered in the pancreas responsible for insulin production. Transplantation of isolated islets is a beneficial therapy for patients with a severe form of type 1 diabetes. The islets, which normally are richly vascularized in the pancreas, are completely disconnected from the vascular support by the enzymatic digestion during the isolation procedure. Islet viability is affected throughout all steps in this process, from donor death and isolation of islets to culturing and the transplantation process itself. In this thesis a novel strategy to promote islet survival and to re-establish islet vasculature is presented. We show endogenous expression of 51 different genes related to inflammation in cultured islets. Among these genes high expression of MCP-1, MIF, VEGF, thymosin b-10 and IL-8, IL-1β, IL-5R-a, IFN-γ antagonist were found in all donors during the 5- and the 2-day cultures, respectively. Protein expression of these genes can stimulate inflammatory immune responses but also promote tissue repair by attracting curative cells such as endothelial cells (EC) leading to re-establishment of the vasculature. We have established a novel technique by formation of composite islets using EC and mesenchymal stem cells (MSC). EC adhered on the surface of the islets and created a potential blood tolerant surface. The EC-islets showed a degree of protection from the detrimental effects of instant blood-mediated inflammatory reaction (IBMIR) with the major components of IBMIR being decreased in in vitro assays. We combined MSC to the EC-islets with success. The MSC were found to have proliferative effect on EC and the combination of these two cell types on the islets further increased the EC covered surface compared to EC-islets. The EC-MSC-islets in co-culture formed vessel-like structures both into the islets and out to the surrounding matrix. The MSC enhanced the exogenous EC to form vessel-like network in the EC-MSC-islets indicating vascular support by the MSC. The novel strategy and conditions presented herein could alleviate problems related to survival of the islets by promoting revascularization. This would open up a new era in islet transplantation and allow more patients to benefit from this therapy. / Clinical immunology, islet group
17

Generation of Therapeutic T Cells for Prostate Cancer

Forsberg, Ole January 2009 (has links)
The work presented herein focuses on the activation of the adaptive immune system in order to develop T cell-based immunotherapy for viral infections and cancer. The main goal was to identify and activate viral or tumoral antigen-specific T cells by using different identification, isolation and stimulation techniques. One such approach was that we modified dendritic cells (DCs) with an adenoviral vector encoding the full length pp65 antigen from cytomegalovirus (CMV). Through strategic modification techniques we demonstrate that it is possible to obtain DCs presenting antigen-specific peptides both on major histocompatibility complex (MHC) class I and MHC class II molecules for simultaneous CD8+ and CD4+ T cell activation. We also demonstrate that it is possible to generate prostate antigen-specific CD8+ T cells from a naïve repertoire of T cells by using DCs and HLA-A2-restricted peptides derived from prostate tumor-associated antigens or by using an adenoviral vector encoding the full length prostate tumor-associated antigen STEAP. We further demonstrate that CD8+ T cells directed against several prostate-specific peptide epitopes can be found in peripheral blood and in the prostate tumor area of prostate cancer patients. Furthermore, we have characterized a number of prostate-derived cell lines in terms of HLA haplotype and tumor-association antigen expression. We concluded that our methods for generating T cells restricted to CMV antigen have the ability to be applied for adoptive T cell transfer to patients with CMV disease and that prostate antigen-specific T cells can be found within prostate cancer patients, which enables future development of immunotherapeutic strategies for prostate cancer.
18

T Regulatory Cells – Friends or Foes?

Lindqvist, Camilla January 2010 (has links)
T regulatory cells (Tregs) have been extensively studied in patients with cancer or autoimmunity. These cells hamper the immune system’s ability to clear tumor cells in cancer patients. In autoimmune diseases, on the other hand, they are not able to restrain autoreactive immune responses. If we manage to understand Tregs and their role in health and diseases we may be able to develop better immunomodulatory therapies. Early studies demonstrated that tolerance was maintained by a subset of CD25+ T-cells. CD25 was the earliest marker for Tregs and is still often used to define these cells. Several Treg-associated markers have been suggested throughout the years. However, these markers can be upregulated by activated T-cells as well. The most specific marker for Tregs is currently the transcription factor forkhead box P3 (FoxP3). In this thesis, we investigated the presence of CD25- Tregs in patients with B-cell malignancies and in patients with autoimmunity. These cells were identified in both patient groups. Further, patients with B-cell malignancies often have high levels of soluble CD25 (sCD25) in the periphery. In our patient cohorts, the level of peripheral Tregs correlated with the level of sCD25 in patients with lymphoma. Tregs were shown to release sCD25 in vitro and sCD25 had a suppressive effect on T-cell proliferation. These data show that Tregs may release CD25 to hamper T-cell proliferation and that this may be an immune escape mechanism in cancer patients. Previous studies have demonstrated that an increased infiltration of FoxP3+ cells into lymphoma-affected lymph nodes is associated with a better patient outcome. This is in contrast to studies from non-hematological cancers where an increased presence of Tregs is associated with a poor prognosis. Since previous studies have shown that Tregs are able to kill B-cells, we wanted to investigate if Tregs are cytotoxic in patients with B-cell tumors. In the subsequent studies, Tregs from patients with B-cell lymphoma and B-cell chronic lymphocytic leukemia (CLL) were phenotyped to investigate the presence of cytotoxic markers on these cells. FoxP3-expressing T-cells from both patients with CLL and B-cell lymphoma displayed signs of cytotoxicity by upregulation of FasL and the degranulation marker CD107a. Tregs from CLL patients could further kill their autologous B-cells in in vitro cultures. Taken together the studies in this thesis have demonstrated two possible new functions of Tregs in patients with B-cell malignancies and the presence of CD25- Tregs in both cancer and autoimmunity.
19

Cytokine responses in human Lyme borreliosis : The role of T helper 1-like immunity and aspects of gender and co-exposure in relation to disease course

Jarefors, Sara January 2006 (has links)
Lyme borreliosis was first described some 30 years ago in the USA. Today, it is the most common vector borne disease in Europe and the USA. The disease can have multiple stages and symptoms can manifest from various parts of the body; joints, skin heart and nervous system. In Europe, neuroborreliosis is the most frequent late stage diagnosis. Although Lyme borreliosis is treatable with antibiotics and the causative spirochete has not been shown to be resistant to drugs, some patients do not recover completely. They have persistent symptoms and are diagnosed with chronic or persistent Lyme borreliosis. The mechanism behind the lingering symptoms is unclear but might be due to tissue damage caused by the immune system. The aim of this thesis was to study the immunological differences between patients with different outcome of Lyme borreliosis, i.e. chronic, subacute and asymptomatic, and various factors that might influence the course of the disease. The Borrelia-specific IFN-γ and IL-4 secretion was detected in blood and cerebrospinal fluid from patients with chronic and subacute neuroborreliosis during the course of the disease. Blood samples were also obtained from patients with erythema migrans (EM) and acrodermatitis chronicum atrophicans. An early increase of IFN-γ with a later switch to an IL-4 response was observed in patients with a subacute disease course whereas the IFN-γ secretion continued to be elevated in chronic patients. The Borrelia-specific Th1-response was further investigated in chronic, subacute and asymptomatic individuals by studying the expression of the Th1-marker IL-12Rβ2, on a protein and mRNA level. The cytokine secretion and Foxp3, a marker for regulatory T-cells, were also analyzed. Chronic patients had a lower IL-12Rβ2 expression on CD8+ T-cells and a lower number of Borrelia-specific IFN-γ secreting cells compared to asymptomatic individuals. Chronic patients also displayed a higher expression of Borrelia-specific Foxp3 than healthy controls. The conclusions for these tow studies were that a strong Th1-response early in the infection with a later switch to a Th2-response is beneficiary whereas a slow or weak Th1-response corresponds to a prolonged disease course. The influence of a previous infection with another pathogen, seen to suppress the immune response in animals, and the possible gender difference in immune response was also investigated. Patients with EM were screened for antibodies to Anaplasma phagocytophilum (Ap) as a sign of a previous exposure to these tick-borne bacteria. Blood lymphocytes from Ap seronegative, Ap seropositive and healthy controls were stimulated with Borrelia antigen and the secretion of IL-4, IL-5, IL-12, IL-13 and IFN-γ was detected by ELISPOT. Ap seropositive patients had a lower number of cells responding with IL-12 secretion compared to the other groups which might indicate an inhibited Th1-response. Reinfections with Lyme borreliosis was in a previous study, done by Bennet et al, found to be more frequent in postmenopausal women than in men. To investigate if there was an immunological explanation to the gender discrepancy, blood lymphocytes from individuals reinfected with Lyme borreliosis and individuals infected only once were stimulated with various antigens. The cytokine secretion was detected by ELISPOT, ELISA and Immulite. There were no differences between reinfected and single infected individuals. However, women, regardless of times infected, displayed a Th2-derived and anti-inflammatory spontaneous immune response compared to men. A previous infection with the bacteria Ap might possibly have a long term effect on the immune system and might be of disadvantage when mounting a Th1-response to a Borrelia infection. Also, the Th2-derived response displayed by postmenopausal women could indicate why more women than men get reinfected with Borrelia burgdorferi. / On the day of the public defence date of the doctoral thesis the status of article III was Accepted; the status of article IV was Submitted and the title was "Importance of induction and secretion of interferon-gamma for optimal resolution of human Lyme borreliosis: differencesbetween different outcomes of the infection".
20

Immunological mechanisms in systemic autoimmunity : autoantibodies and chemokines in systemic lupus erythematosus and during treatment with TNF inhibitors in rheumatoid arthritis

Eriksson, Catharina January 2011 (has links)
Background. Rheumatoid Arthritis (RA) is an autoimmune inflammatory disease that, without powerful treatment, may lead to irreversible joint damage. During the past decade, anti-cytokine therapy has become available, e.g., infliximab, a chimeric antibody targeting the pro-inflammatory cytokine TNF that has a central role in the inflammatory process in RA patients. Systemic Lupus Erythematosus (SLE) is a systemic autoimmune disease that may affect all organs and is characterized by a massive antibody production. Chemokines, chemokine receptors and lipoprotein receptor-related protein 1(CD91) are regulators of inflammation in autoimmune diseases and T-cell migration. Objectives. The aim of this study was to get a deeper understanding how TNF blocking treatment influences inflammatory mechanisms and autoantibody formation in RA with special reference to similarities and differences with SLE. Methods. In patients with RA treated with anti-TNF, and in SLE patients (ACR criteria) clinical evaluation was performed and blood samples analyzed. Autoantibodies were analyzed using indirect immunofluorescence, ELISA and multiplex flow cytometry in samples from anti-TNF treated RA patients (n=59) followed longitudinally for 54 weeks, in pre-diseased samples from SLE patients (n=38) and matched population-based controls (n=152). T-cell expression of chemokine receptors and CD91 was analyzed by flow cytometry, whilst serum levels of chemokines were determined using ELISA in anti-TNF treated RA-patients (n=24) followed longitudinally (30 weeks), and cross-sectionally in SLE-patients (n=23). Expression of mRNA for chemokines was analyzed in T-cells from SLE-patients (n=10) using PCR. Results. After treatment with infliximab, RA patients produced ANA, anti-dsDNA and anti-nucleosome antibodies, but not anti-ENA antibodies. Although these antibodies are considered typical for SLE only one patient developed a transient lupus-syndrome. Antibodies against cell nuclear antigens, including ENA, were detected several years before the first clinical symptom of SLE; anti-SSA was the earliest detectable antibody. In RA-patients before infliximab treatment, the T-cell expression of several chemokine receptors was elevated compared with healthy controls. In contrast, only one soluble chemokine, IP-10 was elevated. After treatment the levels of soluble MIP-1β, MCP-1 and IP-10, and the T-cell expression of CCR2 were decreased. In SLE-patients MIP-1β, MCP-1, SDF-1, IP-10 and RANTES in blood were elevated, whilst expression of CXCR5 and CCR6 on T-cells was lower than in healthy controls. T-cell expression of CXCR2 and CCR1 was elevated in active disease (measured as SLEDAI index), whereas the CXCR5 and CCR2 expression was lower in inactive SLE. In SLE patients with nephritis IP-10 was lower and T-cell expression of CXCR3 and CCR3 elevated compared with patients without nephritis. The expression of CD91 was higher on T-cells from patients not responsive to infliximab treatment compared with responders. Conclusion. These findings indicate that anti-TNF (infliximab) treatment in RA-patients has a major impact on the production of autoantibodies and chemokines. The autoantibody profile in infliximab-treated patients was similar to that predating disease onset in SLE patients with the exception of anti-ENA being detectable in SLE, but the development of lupus-syndromes was rare. The expression of CD91 on T-cells may predict responsiveness to infliximab. The expression of chemokine receptors in SLE- patients seemed to be related to disease activity. Anti-nuclear antibodies were detectable years before clinical disease onset in patients who developed SLE suggesting a gradual pathogenic process.

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