Orientador: Sônia Maria Alves Bueno / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-18T20:07:57Z (GMT). No. of bitstreams: 1 Pavan_GiseleLuiza_M.pdf: 8113456 bytes, checksum: 17ffd6547356e32bd63a48ccb9192979 (MD5) Previous issue date: 2011 / Resumo: Imunoglobulinas são anticorpos secretados por células imunitárias em resposta a introdução de um antígeno. A imunoglobulina G (IgG) de origem humana, com alto grau de pureza, tem sido empregada como prescrição terapêutica para inúmeros casos de doenças malignas, infecciosas, auto-imunes e inflamatórias. Normalmente, a IgG é purificada através da precipitação com etanol seguida de cromatografia de afinidade com proteína A ou G imobilizada, no entanto, por apresentar alto custo, se faz necessário o desenvolvimento de técnicas de afinidade alternativas. Membranas, nas quais podem ser imobilizados os ligantes de afinidade, tornam-se uma alternativa aos géis tradicionais apresentando maior capacidade hidrodinâmica. Neste contexto, estudou-se o efeito da remoção do sal em diferentes sistemas tamponantes na purificação de IgG a partir do soro humano por cromatografia de afinidade com íons imobilizados (IMAC), para o módulo de membranas de fibras ocas de PEVA-CM-Asp- Me2+, para os íons metálicos níquel e cobalto. De acordo com eletroforeses SDS-PAGE e análises de nefelometria das frações dos picos de proteína obtidos, a melhor condição utilizada para a purificação de IgG para os adsorventes PEVA-CM-Asp-Ni2+ e PEVA-CM-Asp-Co2+, foi em presença do sistema tamponante fosfato de sódio 25 mmol L-1 e imidazol 2 mmol L-1 a pH 7,0 utilizando o aumento da concentração de imidazol como estratégia de eluição, alcançando pureza superior a 93% para ambos íons metálicos. Determinada a melhor condição de purificação, por meio das isotermas de adsorção, foi determinada a capacidade máxima de adsorção e a constante de dissociação dos complexos CM-Asp-Ni2+-IgG e CM-Asp-Co2+-IgG que, de acordo com o ajuste dos parâmetros pelo modelo de Langmuir e Langmuir-Freundlich, demonstraram boa capacidade de adsorção e constantes de dissociação características de sistemas utilizando ligantes pseudobioespecíficos. Para as filtrações em módulo de fibras ocas, construído em nosso laboratório, determinaram-se as curvas de ruptura, sendo que os resultados obtidos para as membranas finamente cortadas foram melhores que os obtidos para os de filtração em módulo de fibras ocas / Abstract: Immunoglobulins are secreted by immune cells in response to the introduction of an antigen. Immunoglobulin G (IgG) obtained from human sources with high purity has been used as therapeutic prescription for many cases of malicious, infectious, autoimmune and inflammatory diseases. Typically, IgG is purified by precipitation with ethanol followed by affinity chromatography with immobilized protein A or G, however, due to its high cost, it is necessary to develop alternative techniques based on affinity. Affinity membranes, which may be immobilized on the affinity ligands, show a higher hydrodynamic capacity than typical gels. In this context, the effect of salt was studied in different buffer systems in the purification of IgG from human serum by Immobilized Metal-ion Affinity Chromatography (IMAC) for the module PEVA-CM-Asp-Me2+ using ions Ni2+ and Co2+. According to SDS-PAGE and nephelometric analysis fractions of protein peaks obtained, the best condition used for purification of IgG to the adsorbents PEVA-CM-Asp-Ni2+ and PEVA-CM-Asp-Co2+ was in the presence of sodium phosphate buffer system 25 mmol L-1 and 2 mmol L-1 imidazole at pH 7.0 using increasing concentration of imidazole as elution strategy, achieving a purity higher than 93% for both metal ions. The maximum adsorption capacity and dissociation constant of complexes CM-Asp-Ni2+-IgG and CM-Asp-Co2+-IgG by adsorption isotherms were determined on the best condition of purification and the adjustment of parameters by the Langmuir and Langmuir-Freundlich models, it demonstrated good adsorption capacity and dissociation constants characteristics of systems using pseudobioespecific ligands. For filtration in hollow fiber module, constructed in our laboratory, breakthrough curves were determined; also for the best condition of purification, and the results for finely chopped membranes were better than those obtained for the filtration module and hollow fibers / Mestrado / Desenvolvimento de Processos Biotecnologicos / Mestre em Engenharia Química

Abstract The characteristics of humoral immunity have been proposed to reflect the bias between two T helper (Th) lymphocyte subsets: Th1 cells, which activate cell-mediated immunity, and Th2 cells, which mediate humoral immunity. The present study aimed to characterize the humoral immunity to beta-cell autoantigens insulin and glutamic acid decarboxylase (GAD65) in preclinical and clinical type 1 diabetes. Insulin antibodies were analyzed in pregnant women with or without type 1 diabetes and their newborn infants and in prediabetic children. Epitope or/and isotype-specific GAD65 antibodies (GAD65Abs) were analyzed in prediabetic children, in children and adolescents diagnosed with type 1 diabetes, and in patients with the autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) syndrome. Antibodies were determined by radioligand immunoassays. The humoral immune response to insulin and GAD65 was observed to be a highly dynamic process, comprising mainly the IgG1 subclass and, less frequently, other IgG subclasses. GAD65Abs were directed primarily to the middle region and secondarily to the C-terminal region of GAD65 as a consequence of epitope spreading. Young children who progressed to overt type 1 diabetes were characterized by a broad initial isotype response to insulin and GAD65 and by a strong IgG1 and IgG3 response to insulin. Children who did not progress to clinical type 1 diabetes were characterized by an emerging IgG4 response to GAD65. Rising levels of GAD65Abs targeted to the middle region of GAD65 were associated with high titers of islet cell antibodies and a decreased requirement for exogenous insulin, probably reflecting a persistent residual beta-cell mass, in patients with manifest type 1 diabetes. Non-immunoglobulin insulin-binding activity was observed to be induced by pregnancy. APECED-associated humoral autoimmunity to GAD65 did not differ markedly from that observed in subjects with type 1 diabetes alone. In conclusion, isotype-specific GAD65 and especially insulin antibodies are valuable markers of the risk of progression to type 1 diabetes in young children. The appearance of an initial IgG3 subclass response and a strong IgG3 response to insulin in children who progressed to overt type 1 diabetes may reflect the role of cytotoxic Th1-biased immunity in the disease process leading to clinical presentation of type 1 diabetes.

Master of Science / Department of Biology / Stephen K. Chapes / Immunoglobulins are receptors expressed on the outside of a B cell that can specifically bind pathogens and toxic substances within a host. These receptors are heterodimers of two chains: heavy and light, which are encoded at separate loci. Enzymatic splicing of gene segments at heavy and light chain loci within the genomic DNA in every B cell results in a highly diversified and specific repertoire of immunoglobulins in a single host. Spaceflight is known to affect reduce splenic B cell populations and B cell progenitors within the bone marrow, potentially restricting the diversity of the immunoglobulin repertoire (Ig-Rep). The objective of this thesis project was to characterize the impact of spaceflight on the kappa light-chain Ig-Rep of the C57BL/6 mouse. High-throughput sequencing (HTS) technologies have enabled the rapid characterization of Ig-Reps, however, standard Ig-Rep workflows often rely the amplification of immunoglobulin sequences to ensure the capture immunoglobulin sequences from rare B cell clones. Additionally, the Ig-Rep is often assessed in sorted B cell populations. Opportunities for spaceflight experiments are limited and costly, and the exclusive amplification of immunoglobulin sequences prior to HTS results in a dataset that cannot be mined for additional information. Furthermore, due to the difficulties of tissue collection in spaceflight, HTS of sorted B cell populations is not feasible. We optimized a protocol in which the Ig-Rep was assessed from unamplified whole tissue immunoglobulin transcripts. The Ig-Rep was characterized by gene segment usage, gene segment combinations and the region in which gene segments are joined. HTS datasets of ground control animals and animals flown aboard the International Space Station were compared to explore the impact of spaceflight on the unimmunized murine Ig-Rep.

Orientador: Sonia Maria Alves Bueno / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-27T12:23:49Z (GMT). No. of bitstreams: 1 Carmignotto_GabrielaPannunzio_M.pdf: 6143089 bytes, checksum: aa61b4762764a38220fc51226e410a80 (MD5) Previous issue date: 2015 / Resumo: Os fragmentos Fab de imunoglobulina G são utilizados principalmente em testes diagnósticos e terapias. Por apresentarem tamanho reduzido, os fragmentos Fab possuem maior facilidade de penetração em tecidos e maior velocidade de circulação no plasma quando comparados à IgG intacta. A purificação dos fragmentos Fab é realizada geralmente por cromatografia de afinidade utilizando os ligantes bioespecíficos proteína A, proteína G e proteína L. Entretanto, esses ligantes apresentam algumas desvantagens, entre elas seu elevado custo e a necessidade de eluição em condições drásticas. Como alternativa, muitos estudos têm sido realizados empregando ligantes pseudobioespecíficos e de interação mista visando o desenvolvimento de novas estratégias que proporcionem a purificação dos fragmentos Fab. Neste contexto, este trabalho tem por objetivo avaliar a seletividade das poliaminas ?-aminohexil e poli(etilenoimina) imobilizadas em gel de agarose na separação de fragmentos Fab humano a partir de uma solução de IgG humana clivada enzimaticamente, empregando diferentes sistemas tamponantes. A recuperação seletiva dos fragmentos Fab foi avaliada por eletroforese SDS-PAGE, Western blot e imunodifusão radial. Os resultados indicaram que nas cromatografias realizadas em gel ?-aminohexil-agarose em Tris-HCl a pH 8,0, os fragmentos Fab foram recuperados nas frações não retidas, com valores calculados de pureza de 97% e recuperação de 100%. Nas cromatografias realizadas em gel PEI-agarose empregando o tampão Tris-HCl nos valores de pH de 7,5 e 8,0, a pureza obtida foi de 96% e a recuperação foi de 94% e 93%, respectivamente. As curvas de ruptura para os adsorventes foram determinadas e os resultados obtidos indicaram melhor recuperação do fragmento Fab com alta pureza no flowthrough para o ligante ?-aminohexil (2,7 mg) quando comparado ao ligante PEI (0,8 mg). A isoterma de adsorção de fragmentos Fc para o adsorvente ?-aminohexil-agarose foi determinada e os parâmetros capacidade de adsorção de 44,32 mg.mL-1 de gel e constante de dissociação de 1,11.10-5 mol.L-1 foram obtidos por ajuste destes parâmetros segundo o modelo de Langmuir-Freundlich. O valor de n obtido foi igual a 1,68, indicando cooperatividade positiva na adsorção dos fragmentos Fc e IgG não clivada. Os resultados mostraram que as poliaminas ?-aminohexil e PEI apresentaram potencial como ligantes para a purificação de fragmentos Fab / Abstract: Fab fragments from immunoglobulin G are considered an important tool for the therapy and diagnose of diseases. Their reduced molecular size is an advantage over the intact IgG allowing faster tissue penetration and circulation in the plasm. Fab fragments are often purified by affinity chromatography using biospecifics ligands, such as protein A, protein G, and protein L. However, the use of those ligands is hindered by their high costs and elution in drastic conditions. Several studies have been performed for the development of new techniques to improve the chromatographic purification of Fab fragment, e.g., using pseudobiospecifics or mix-mode ligands. In this context, we have evaluated the efficiencies of polyamines ?-aminohexyl and poly(ethyleneimine) (PEI) ligands immobilized in agarose gel aiming the purification of human Fab fragments. Our chromatographic studies were conducted feeding cleaved human IgG solution into the aforementioned adsorbents using different adsorption buffers and conditions. The selectivity towards Fab fragments was evaluated using SDS-PAGE, Western blot, and radial immunodiffusion. The chromatography performed with ?-aminohexyl-agarose using Tris-HCl buffer pH 8.0 recovered 100% of the Fab fragments with 97% of purity. Studies done with adsorbent PEI-agarose using Tris-HCl pH 7.5 and 8.0 as adsorption buffers recovered 94% and 93% of Fab fragments, respectively, with 97% of purity. Breakthrough curves experiments showed that the ?-aminohexyl ligand was superior than PEI ligand in terms of recovering Fab fragment with high purity in flowthrough (2.7 mg against 0.8 mg, respectively). The adsorption isotherm of ?-aminohexil-agarose adsorbent was determined adjusted by the Langmuir-Freundlich model as well (Qm: 44.32 mg.mL-1 of gel; Kd: 1.11.10-5 mol.L-1). Additionally, Fc fragments and IgG binding showed positive cooperativity (n=1.68). All these results indicate that ?-aminohexyl and PEI polyamines are potential ligands for the purification of Fab fragments and can possibly improve the existing techniques employed for this purpose / Mestrado / Desenvolvimento de Processos Biotecnologicos / Mestra em Engenharia Química

Receiving a breast cancer (BC) diagnosis generates significant physical and psychological stress that may persist months, years, or even decades beyond treatment completion. Such chronic stress can severely alter the biological systems of BC survivors (BCS). Yet, little is known about the impact and associated variables of these long-term physiological sequelae. Considering that the number of BCS continues to grow each year, it is imperative to assess the extent to which a BC experience impacts human physiological mechanisms by examining the secretion patterns of associated stress- and immune-related biomarkers and by exploring the behavioural, physical, and psychological variables implicated in these dysregulations. Such research is of particular importance in order to guide cancer survivorship care and develop interventions promoting optimal health outcomes in BCS. This research program sought to address this through three inter-related studies. Study One was a quasi-experimental design study examining both the diurnal and reactive concentration patterns of secretory immunoglobulin A (SIgA) in a sample of women with (n = 22) and without a prior history of BC (n = 26). SIgA concentration patterns were contrasted to concentration patterns of cortisol and salivary alpha-amylase (sAA) in the same individuals (complementary to two previously published studies). Participants supplied saliva samples at five time points on two consecutive typical days (for diurnal data) and at seven time points before, during, and after an acute laboratory stressor (for reactive data). Results reveled no evidence of uncharacteristic SIgA diurnal or reactive concentration patterns, suggesting a normal and well-functioning immunological SIgA system in BCS on average 4.6 years post-diagnosis. Study One acted as a summary article allowing readers to grasp the "big picture" of long-term physiological dysregulations in BCS as a whole. Building on this, Study Two, which used the same dataset as Study One, aimed to determine whether physical activity (PA) could mitigate the adverse physiological effects of a BC experience in BCS (n = 25), as indexed by their cortisol concentration patterns. Participants self-reported their PA frequency and engaged in the same cortisol assay protocol reported in Study One. Results indicated no statistically significant differences in diurnal and reactive cortisol patterns between low- and high-PA groups. A trend that PA might not have the same effect on women with and without a history of BC was noted. Important limitations to Study Two included the small sample size and the lack of sensitivity and objectivity of the PA measure. To address Study Two’s limitations and to consider a wider range of modifiable variables that could contribute to the physiological dysregulations observed in BCS, Study Three aimed to assess the predictive value of six behavioural, physical, and psychological variables on the physiological effects of a BC experience, as indexed by cortisol (n = 192) and C-reactive protein (CRP; n = 168) levels over the first 1.5 year post-treatment. CRP, a biomarker that had not been considered so far in this research program, allowed to assess systemic inflammation in BCS post-treatment. Study Three also aimed to describe naturally occurring changes in cortisol and CRP levels and assess whether they changed in tandem. Data were drawn from 201 BCS who provided capillary blood and saliva samples at approximately 3.5 months post-treatment and again 3, 6, 9, and 12 months later. At each time point, participants also completed self-report questionnaires and wore an accelerometer for seven consecutive days. Multilevel modeling analyses revealed no significant change over time for cortisol levels post-treatment and a non-linear trajectory of change for CRP levels which was not predicted by cortisol levels. Associations between cortisol and sedentary time as well as associations between CRP and PA, body mass index, and health- and cancer-related stress were found. Collectively, these three inter-related studies uniquely add to the literature by describing long-term physiological trajectories of stress- and immune-related biomarkers in BCS. This research program attempts to gain a better understanding of the underlying mechanisms that tie behavioural, physical, and psychological variables and biomarker secretion to a BC experience. It also offers opportunities to identify women at greater risk of physiological dysregulations following a BC experience. This represents an important step towards the development of tailored interventions targeting specific BCS that most warrant them. With the number of BCS climbing each year, cancer survivorship needs to be a priority in research and efforts to better understand, monitor, and mitigate the physiological consequences of a BC experience are critical.

In meeting the high demand for monoclonal antibodies, the chicken immunoglobulin system was exploited to generate recombinant antibodies against multiple target antigens. Following simultaneous immunisation of two chickens with a mixture of Plasmodium falciparum recombinant lactate dehydrogenase (LDH), histidine rich protein II (HRPII) and aldolase (ALDO), recombinant trypanosome variable surface glycoprotein (VSG) and malignant catarrhal fever virus (MCFV) each chicken produced egg yolk antibodies (IgY) against four of the five antigens. Using phage display technology, two single-chain variable fragment (scFv) antibody libraries, one with the immunoglobulin VH and VL chain regions joined by a single amino acid (G) and the other with a 15 amino acid flexible linker [(G4S) 3] were constructed using pooled splenic RNA. The single amino acid-linked scFv repertoire was evaluated as a source of highly specific diagnostic antibodies by panning against each of the five different antigens. After two rounds of panning, polyclonal phage ELISA showed the presence of antigen-specific phage antibodies against three (LDH, HRPII and VSG) of the five antigens. Five different anti-LDH and six different anti-HRPII scFvs were identified by sequence analysis. Evidence of high levels of antigen-driven gene conversion events was found in the framework and complementary determining regions and the VL chain pseudogene donors were identified. Stability of the selected scFvs was determined by incubation at different times and at different temperatures. The specificity and potential use of an LDH-specific scFv as a diagnostic reagent was shown in sandwich and competitive inhibition ELISAs. / Dissertation (MSc (Veterinary Science))--University of Pretoria, 2007. / Veterinary Tropical Diseases / unrestricted

Urticaria can be a chronic and debilitating affliction and is a relatively common disorder affecting between 10- 20% of the population. Common causes include reactions to medication, food allergen, physical stimuli and venoms. Urticaria can be acute or chronic. Chronic urticaria lasts for more than 6 weeks and is commonly difficult to treat. The use of immunosuppressive agents for this disorder when antihistamines fail can result in significant morbidity. Recent advances in the pathogenesis, etiology, diagnosis and management of chronic urticaria have led to new paradigms in treatment of this disorder. Cyclosporine is often the most effective but has some unique adverse effects that may prevent it from being used in some patients. The use of intravenous immunoglobulin (IVIG) has proven effective in a variety of reports and we will review the mechanisms likely involved in the successful control of urticarial symptoms by immunomodulating therapy using IVIG. In this review, we will discuss mechanisms and pathogenesis of urticaria and the specific role of intravenous immunoglobulin (IVIG) in this disorder, especially in refractory or steroid-dependent cases.

Indiana University-Purdue University Indianapolis (IUPUI) / Secretory immunity is believed to play a role in natural resistance to dental caries. Although dental caries has dramatically decreased in children in the United States, there remains a population of caries-susceptible children even in fluoridated communities. Previous studies have shown a positive correlation between salivary immunoglobulin A (sIgA) antibody levels to Streptococcus mutans and caries resistance in adults. In the present study, an enzyme-linked immunosorbent assay (ELISA) was used to compare IgA antibody levels to S. mutans in saliva from 20 caries susceptible (DMFS greater than 5) and 20 caries-resistant (DMFS less than or equal to 1) children (ages 7-11). All subjects resided in fluoridated communities. Salivary S. mutans numbers were significantly higher (p ≤ 0.05) in the caries susceptible (31.2 percent of total streptococci) group than in the caries resistant (1.6 percent of total streptococci) group. Whole saliva from caries-resistant children had significantly higher (p = 0.05) levels of IgA antibodies to S. mutans than saliva from caries-susceptible children. However, whole saliva from caries-resistant children had similar levels of IgA1 or IgA2 antibodies against S. mutans to saliva from caries-susceptible children. These results suggest that IgA antibody to S. mutans may play a role in natural protection from dental caries in children and confirm previous reports indicating a role for salivary IgA antibodies to S. mutans in mediation of caries.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18179号 / 医博第3899号 / 新制||医||1004(附属図書館) / 31037 / 京都大学大学院医学研究科医学専攻 / (主査)教授 清水 章, 教授 岩井 一宏, 教授 生田 宏一 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Background: The city of Manaus, Brazil, has seen two collapses of the health system due to the COVID-19 pandemic. We report anti-SARS-CoV-2 nucleocapsid IgG antibody seroconversion rates and associated risk factors in Manaus residents before the second wave of the epidemic in Brazil. Methods: A convenience sample of adult (aged ≥18 years) residents of Manaus was recruited through online and university website advertising into the DETECTCoV-19 study cohort. The current analysis of seroconversion included a subgroup of DETECTCoV-19 participants who had at least two serum sample collections separated by at least 4 weeks between Aug 19 and Oct 2, 2020 (visit 1), and Oct 19 and Nov 27, 2020 (visit 2). Those who reported (or had no data on) having a COVID-19 diagnosis before visit 1, and who were positive for anti-SARS-CoV-2 nucleocapsid IgG antibodies at visit 1 were excluded. Using an in-house ELISA, the reactivity index (RI; calculated as the optical density ratio of the sample to the negative control) for serum anti-SARS-CoV-2 nucleocapsid IgG antibodies was measured at both visits. We calculated the incidence of seroconversion (defined as RI values ≤1·5 at visit 1 and ≥1·5 at visit 2, and a ratio >2 between the visit 2 and visit 1 RI values) during the study period, as well as incidence rate ratios (IRRs) through cluster-corrected and adjusted Poisson regression models to analyse associations between seroconversion and variables related to sociodemographic characteristics, health access, comorbidities, COVID-19 exposure, protective behaviours, and symptoms. Findings: 2496 DETECTCoV-19 cohort participants returned for a follow-up visit between Oct 19 and Nov 27, 2020, of whom 204 reported having COVID-19 before the first visit and 24 had no data regarding previous disease status. 559 participants were seropositive for anti-SARS-CoV-2 nucleocapsid IgG antibodies at baseline. Of the remaining 1709 participants who were seronegative at baseline, 71 did not meet the criteria for seroconversion and were excluded from the analyses. Among the remaining 1638 participants who were seronegative at baseline, 214 showed seroconversion at visit 2. The seroconversion incidence was 13·06% (95% CI 11·52–14·79) overall and 6·78% (5·61–8·10) for symptomatic seroconversion, over a median follow-up period of 57 days (IQR 54–61). 48·1% of seroconversion events were estimated to be asymptomatic. The sample had higher proportions of affluent and higher-educated people than those reported for the Manaus city population. In the fully adjusted and corrected model, risk factors for seroconversion before visit 2 were having a COVID-19 case in the household (IRR 1·49 [95% CI 1·21–1·83]), not wearing a mask during contact with a person with COVID-19 (1·25 [1·09–1·45]), relaxation of physical distancing (1·31 [1·05–1·64]), and having flu-like symptoms (1·79 [1·23–2·59]) or a COVID-19 diagnosis (3·57 [2·27–5·63]) between the first and second visits, whereas working remotely was associated with lower incidence (0·74 [0·56–0·97]). Interpretation: An intense infection transmission period preceded the second wave of COVID-19 in Manaus. Several modifiable behaviours increased the risk of seroconversion, including non-compliance with non-pharmaceutical interventions measures such as not wearing a mask during contact, relaxation of protective measures, and non-remote working. Increased testing in high-transmission areas is needed to provide timely information about ongoing transmission and aid appropriate implementation of transmission mitigation measures. Funding: Ministry of Education, Brazil; Fundação de Amparo à Pesquisa do Estado do Amazonas; Pan American Health Organization (PAHO)/WHO. / World Health Organization / Revisión por pares