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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.
321

Avaliação da suplementação parenteral de cobre e zinco em vacas e bezerros Nelore / Evaluation of copper and zinc parental supplementation on Nelore cows and calves

Janaína Silveira da Silva 06 February 2015 (has links)
O presente estudo avaliou o efeito da suplementação mineral injetável de cobre (Cu) e zinco (Zn) sobre a resposta imunológica e o desempenho de bovinos de corte a pasto, foram avaliadas vacas no período pré-parto (experimento I) e seus bezerros até pós desmama (experimento II). O experimento foi realizado na Faculdade de Zootecnia e Engenharia de Alimentos da USP, Campus de Pirassununga-SP. No experimento I, foram avaliadas sessenta vacas prenhas por inseminação, distribuídas aleatoriamente em delineamento inteiramente casualizado com dois tratamentos (T e S). No tratamento testemunha (T), as vacas receberam soro fisiológico como placebo, e no tratamento suplementado (S) receberam mineral injetável via subcutânea (75 mg de cobre e 250 mg de zinco), com aproximadamente 75 dias antes do parto. Foram avaliados os teores de Cu e Zn séricos, IgG e IgM, ceruloplasmina e a atividade fagocitária. Os dados experimentais foram analisados utilizando-se o PROC MIXED do SAS (SAS, 2009), com o nível de significância de 5% para interpretação estatística de todos os testes. Os teores de cobre, zinco, IgM, IgG, ceruloplasmina e a atividade fagocitária das vacas não apresentaram diferença (p>0,05) entre os tratamentos. Da mesma forma, não houve influencia (p>0,05) das vacas nos teores de Cu e Zn séricos, na resposta imunológica e no desempenho dos bezerros aos 70 dias de idade (primeira coleta de sangue). O fornecimento de Cu e Zn injetável aos 75 dias antes do parto não alterou os teores de zinco, cobre e ceruloplasmina sérica, bem como a resposta imunológica até 30 dias após o parto. Como não houve diferença significativa entre as mães, foi considerado que os bezerros eram provenientes de vacas homogêneas. Assim, no experimento II, cinquenta e quatro bezerros filhos destas vacas, foram distribuídos aleatoriamente em delineamento inteiramente casualizado em 2 tratamentos: (T) - bezerros não suplementados, que receberam soro fisiológico como placebo; (S) - bezerros suplementados com cobre (15 mg aos 70 dias, 45 mg aos 140 dias e 60 mg aos 210 dias) e zinco (50 mg aos 70 dias, 150 mg aos 140 dias e 200 mg aos 210 dias). Foram realizadas colheitas de sangue com aproximadamente 70, 140, 170, 210 e 240 dias de idade, para avaliação dos teores de Cu e Zn sérico, ceruloplasmina, IgG e IgM e a atividade fagocitária. A suplementação parenteral de Cu e Zn aos 70, 140 e 210 dias não alteraram (p>0,05) os teores de Cu e Zn séricos, a resposta imunológica, o desempenho, a atividade da enzima superóxido dismutase e a atividade fagocitária de bezerros Nelore. A falta de resposta ao suplemento mineral injetável deveu-se possivelmente ao fato dos bezerros já estarem recebendo as quantidades adequadas de cobre e de zinco nas suas dietas. / This study evaluated the effect of injectable Cu and Zn on the immune response and performance of beef cattle on pasture, cows were evaluated in the antepartum period (experiment I) and their calves to post weaning (experiment II). The experiment was perfomed at the Faculty of Animal Science and Food Engineering, University of São Paulo, Campus Pirassununga. In experiment I, sixty pregnant Nelore cows by insemination were divided in a completely randomized design in two treatments. In the control treatment (T), the 30 cows received saline as placebo, the supplemented (S) received mineral injection subcutaneously (75 mg of copper and 250 mg of zinc), 75 days prior to parturition, when also received clostridiosis vaccine. It were evaluated the serum levels of Cu and Zn, IgG, and IgM, ceruloplasmin, SOD and phagocytic activity. Experimental data were analyzed using PROC MIXED of SAS (SAS, 2009), with 5% significance level for statistical interpretation of all tests. The levels of copper, zinc, IgM, IgG, ceruloplasmin and the phagocytic activity of the cows had no statistical difference (p>0.05) between treatments. Similarly, there wasn\'t influence (p>0.05) of cows for Cu and Zn serum, immune response and performance of calves at 70 days of age (first blood sample). The supply of Cu and Zn injection at 75 days before delivery did not change the levels of zinc, copper and serum ceruloplasmin and the immune response 30 days after delivery. Since there was no significant difference between the mothers, it was considered that the calves were from homogeneous cows. In experiment II, fifty four calves born from these cows were distributed completely randomized design with 2 treatments: (T) - calves not supplemented that receive solution saline as placebo and (S) - calves supplemented with injectable mineral applied subcutaneously containing copper (15 mg at 70 days, 45 mg at 140 days and 60 mg at 210 days) and zinc (50 mg at 70 days, 150 mg at 140 days and 200 mg at 210 days. Blood samples were realized with approximately 70, 140, 170, 210 and 240 days of age. Were assessed levels of serum Cu and Zn, ceruloplasmin, IgG and IgM and the phagocytic activity. Parenteral supplementation of Cu and Zn at 70, 140 and 210 days didn\'t alter (p>0.05) the contents of Cu and Zn serum, the immune response, performance, activity of superoxide dismutase and the phagocytic activity of Nelore calves. The lack of response to injectable mineral supplement possibly was due to the fact that the calves were already taking adequate amounts of copper and zinc in their diets.
322

"Internalização de Imunoglobinas por Células Endoteliais do Fígado, Pulmão e Rim na Leishmaniose Visceral em Ramster". / Internalization of immunoglobulins by endothelial cells in the liver, lung and kidney in hamster with visceral leishmaniasis

Regiane Mathias 05 July 2001 (has links)
A patogenia na leishmaniose visceral (LV) não é totalmente conhecida. Em LV em hamsteres avaliamos a participação de imunoglobulinas nas lesões. IgG foi detectada no sinusóide hepático, nos septos pulmonares e nos capilares glomerulares, em maior intensidade aos 30 e 45 dias pós-infecção (PI); C3 estava ausente, exceto no rim. Os dados não sendo compatíveis com a deposição de imunocomplexo, estudamos ultraestruturalmente a internalização de imunoglobulinas. No fígado e no rim a quantidade de imunoglobulina em célula endotelial era maior aos 30 dias PI em relação ao controle não infectado e no pulmão, aos 30 dias PI em relação aos 60 dias PI. Imunoglobulina internalizada por célula endotelial observada neste estudo na LV em hamsteres, marcadamente aos 30 dias PI, pode ser um mecanismo alternativo de lesão na LV / Pathogenesis of visceral leishmaniasis (VL) is not fully known. In VL in hamsters we evaluated the participation of immunoglobulins in the lesions. IgG was detected in the hepatic sinusoid, in the lung alveolar walls and in the glomerular capillaries in higher intensity at 30 and 45 days post-infection (PI); there were no C3, except in the kidney. Since the data were not compatible with immune complex deposition, we studied ultraestructurally the internalization of immunoglobulins. In the liver and in kidney the amount of immunoglobulin within endothelial cells was greater at 30 days PI than in non infected control, and in the lung at 30 days PI in relation to 60 days PI. Immunoglobulin internalized by endothelial cells observed in VL in hamsters, remarkably at 30 days PI, may be an alternative mechanism of lesion in VL
323

Caractéristation des lymphocytes T auxiliaires impliqués dans la régulation de la réponse humorale

Eddahri, Fouad January 2007 (has links)
Doctorat en Sciences / info:eu-repo/semantics/nonPublished
324

Avaliação da ação neutralizante e da reatividade de anticorpos IgA e IgG anti-rotavírus SA-11 em soro de adultos saudáveis. / Evaluation of neutralizing ability and reactivity of anti-rotavirus SA-11 IgA and IgG antibodies in serum samples from healthy adults.

Thalita Lopes Ferreira 17 May 2011 (has links)
O rotavírus é a principal causa de diarréia em crianças em todo o mundo. Infecta também adultos, mas não há dados completos sobre a sua incidência nesse grupo nem sobre o papel de anticorpos preexistentes na proteção contra o vírus. O objetivo do trabalho foi avaliar a presença de anticorpos IgA e IgG anti-rotavírus SA-11, por ELISA, em amostras de soro de adultos saudáveis e sua ação neutralizante frente ao vírus, em ensaios de neutralização. Por Immunoblotting foi avaliado o reconhecimento de proteínas virais pelos anticorpos séricos. Observou-se que os títulos das amostras foram muito variáveis, sendo os de IgG superiores aos de IgA. Todas as amostras mostraram-se capazes de neutralizar o vírus em diferentes níveis, porém não foi possível estabelecer uma correlação com os títulos de anticorpos. Foi observado que anticorpos da classe IgG reconhecem mais proteínas virais que os da classe IgA. Este trabalho pode ser considerado mais um passo na elucidação do papel dos anticorpos séricos IgA e IgG anti-rotavírus na infecção em adultos. / Rotavirus has been considered the leading cause of diarrhea in children worldwide. The virus also infects adults but there is no conclusive data neither on the incidence of infection on this group nor on the role of pre-existing antibodies. The aim of the work was to evaluate the presence of anti-rotavirus SA-11 IgA and IgG by ELISA in serum samples of healthy adults and the serum neutralizing ability against the virus by neutralization assays. Immunoblotting was used to evaluate viral proteins recognition by serum antibodies. The antibody titers were extremely variable where IgG titers are greater than IgA ones. All samples were able to neutralize the virus in different levels but it was not possible to establish a correlation between antibody titers and neutralization ones. Immunoblotting assays revealed that IgG antibodies recognize more viral proteins than IgA did. This work can be considered a valuable step for elucidating the role of serum anti-rotavirus IgG and IgA antibodies in adults infection.
325

Efeitos do colostro comercial em pó na primeira mamada na saúde e desempenho de bezerras mestiças das raças Holandês (H) x Gir (G) /

Vasconcelos, Paula Carneiro January 2019 (has links)
Orientador: Mateus José Rodrigues Paranhos da Costa / Resumo: Objetivou-se avaliar a eficácia do uso do colostro comercial em pó como substituto do colostro de vaca na primeira mamada de bezerras. Foram utilizadas 31 bezerras mestiças Holandês (H) x Gir (G), provenientes dos grupos genéticos 3/4HG, 5/8HG, 7/8HG e LA, divididas em dois grupos experimentais: G1 (n=15) 2L de colostro de vaca e G2 (n=16) 470g de colostro comercial em pó (SCCL, Saskatoon, SK, Canadá) diluídos em 1,5L de água morna, ambos fornecidos nas primeiras três horas de vida, e posteriormente recebendo mais 2L de colostro de vaca em até 12 horas após o nascimento. As concentrações de IgG presentes (p=0,006) foram maiores no colostro comercial em pó, enquanto as médias da β- caseína (p<0,0001), haptoglobina (p<0,0001) e α1-glicoproteína ácida (p=0,002) foram maiores nos colostros de vaca. As concentrações séricas de PT (G1 = 7,70 ± 1,00g/dL e G2 = 6,73 ± 0,65g/dL; p=0,003) e IgG (G1 = 2110,25 ± 595,03mg/dL e G2 = 1567,6 ± 418,25mg/dL; p=0,004) demonstraram diferenças estatísticas entre os grupos de manejo, com maiores médias para o G1. Houve diferenças significativas para a concentração de albumina sérica (p=0,005), com maiores médias para o G1 (4660,7 ± 384,61mg/dL). Não ocorreu diferença significativa para a haptoglobina sérica (p=0,29), porém suas concentrações médias se apresentaram bem mais altas em ambos os grupos de manejo (G1 = 33,86 ± 4,90 e G2 = 29,31 ± 5,63mg/dL). As enfermidades com maior ocorrência foram diarreia e pneumonia, sendo registrados também casos ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The purpose of this study was value the effectiveness in commercial colostrum powder using as a cow colostrum substitute in the first calf suckling. Twenty-one Holstein (H) x Gir (G) crossbred calves from 3/4HG, 5/8HG, 7/8HG and LA genetic groups were divided into two experimental groups: G1 (n = 15) 2L of cow colostrum and G2 (n = 16) 470g of commercial powdered colostrum (SCCL, Saskatoon, SK, Canada) diluted in 1.5L of warm water, both supplied within the first three hours of life, and subsequently receiving an additional 2L of cow colostrum in up to 12 hours after birth. Present IgG concentrations (p = 0.006) were higher in commercial powdered colostrum, while mean β-casein (p < 0.0001), haptoglobin (p <0.0001) and α1-acid glycoprotein (p = 0.002) were higher in cow colostrums. Serum concentrations of PT (G1 = 7.70 ± 1.00 g/dL and G2 = 6.73 ± 0.65 g/dL; p = 0.003) and IgG (G1 = 2110.25 ± 595.03 mg/dL and G2 = 1567.6 ± 418.25 mg/dL; p = 0.004) demonstrated statistical differences between management groups, with higher means for G1. There were significant differences in serum albumin concentration (p = 0.005), with higher means for G1 (4660.7 ± 384.61mg / dL). There was no significant difference for serum haptoglobin (p = 0.29), but its mean concentrations were much higher in both management groups (G1 = 33.86 ± 4.90 and G2 = 29.31 ± 5.63 mg/dL). The most common diseases were diarrhea and pneumonia, with cases of parasitic sadness and omphalitis, and two deaths in G2. Althou... (Complete abstract click electronic access below) / Mestre
326

Slepičí protilátky jako prostředek pasivní imunizace proti mikrobiálním onemocněním dýchacího traktu / Chicken antibodies as a tool of passive immunization against microbial diseases of respiratory tract

Růžička, Martin January 2010 (has links)
Pseudomonas aeruginosa and Burkholderia cepacia are opportunistic human pathogens. Hazards pose to immunocompromited patient groups, most of whom are patients suffering from cystic fibrosis, for which is the infection caused by Pseudomonas aeruginosa or Burkholderia cepacia, often lethal. Bacteria exhibit resistance to most antibiotics and the immunization of patients, paradoxically, worsens the patients' condition. Hen antibodies, unlike mammalian do not activate the complement cascade and do not cause the inflammatory response, therefore, seem to be a suitable tool to protect high risk populations as a means of passive immunization. In this work were prepared specific chicken antibodies against significant virulent factor - bacterial lectins PAIIL and BClA responsible for adhesion. Antibody specificity was demonstrated by ELISA and Western blot. Antibodies were affinity purified and cleaved to fragments. Pneumocytes type II from the lungs of patients with Cystic Fibrosis were isolated and cultured. Tests of the adhesion of bacteria cells were performed on them using ELISA. As an alternative model rat pneumocytes and tumor cell line A549 has been used. Prepared antibodies specifically detect bacterial lectins on the surface of bacteria. Antibody has been shown to reduce adhesion of bacteria to...
327

Visualizing cell surface interactions using cryogenic electron microscopy

Rapp, Micah January 2021 (has links)
The study of the three-dimensional structures of biological macromolecules has given us significant insight into life and its mechanisms. Understanding these structures in their native contexts, a challenging but important goal, came closer to reality with the development of electron microscopy. After many years of technological development, we are now starting to understand previously intractable biological phenomena at an unprecedented resolution. One such phenomenon is how neighboring cells interact, both to communicate and send signals, and to adhere and form complex tissue structures. While the molecules that mediate such processes have long been studied in isolation, electron microscopy allows us to examine them in a more native biophysical environment; as hydrated, dynamic molecules tethered to opposed cellular membranes.Imaging unadulterated biological material using electron microscopy requires that the sample be embedded in a thin layer of vitreous ice to immobilize the molecules and protect them from the vacuum of the microscope, and thus is generally referred to as cryogenic electron microscopy (cryo-EM). Samples can be imaged using two common cryo-EM modalities: single particle analysis (SPA), where many two-dimensional projection images of molecules in solution are collected, and cryo-electron tomography (cryo-ET), where the sample is tilted as it is imaged at multiple angles to reconstruct a three-dimensional volume. In this work, I will describe how I have used both SPA and cryo-ET to understand cell surface interactions involving a variety of proteins. The first chapter will look at the cell surface molecules known as the Toll receptors, a family of molecules found in Drosophila melanogaster, with orthologs in mammals known as the Toll-like receptors (TLRs). I will focus on their role in the development of the Drosophila embryo during germ band extension, a kind of convergent extension that is a conserved process through all metazoans. Biophysical assays of the three implicated Toll receptors, Toll-2, -6, and -8, revealed both homophilic and heterophilic interactions. SPA was used to determine the structure of monomeric Toll-2 which closely resembles the overall fold of Toll, whose structure was previously solved by x-ray crystallography. Surface plasmon resonance (SPR) spectroscopy and analytical ultracentrifugation (AUC) showed Toll-6 is a dimer in solution, which I visualized using cryo-EM. The Toll-6 homodimer is a novel dimer interface for Tolls and TLRs, where molecules on the same cell surface have been shown to dimerize in the presence of a wide variety of ligands. In contrast, the Toll-6 dimer is formed in the absence of any ligand and exists in an antiparallel arrangement that could be formed by molecules on opposing cell surfaces. Together, these results provide a biochemical basis for germ band extension which may be further explored through the study of structure-based mutations. While cryo-EM SPA is a powerful tool, cryo-ET allows one to reconstruct three dimensional volumes of highly heterogeneous samples, such as the interior of cells, where molecules of interest may not exist in enough copies to facilitate averaging. This technique, where the sample is imaged multiple times as it is tilted to obtain three-dimensional information of a region of interest, was used to study cell adhesion of a different type: that mediated by the classical cadherins. These calcium-dependent adhesion molecules cluster into adherens junctions, spot-like protein densities found in a wide variety of tissues. In the second chapter, these junctions are recapitulated between synthetic liposome membranes by tethering the adherent cadherin molecules to chemically functionalized lipids. They are then imaged using cryo-ET to reveal higher-order structural details. First, this method is applied to the clustered protocadherins, a family of cadherins that mediate neuronal self-avoidance in mammals. Cryo-ET in combination with x-ray crystallography revealed that clustered protocadherins form extended one-dimensional zippers between membranes, which are a combination of strictly homophilic trans interactions coupled with promiscuous cis interactions. Neurons express unique subsets of the ~50-60 possible isoforms, and when two neuronal processes express identical subsets, which happens only when those processes are a part of the same cell, these linear chains grow and initiate a repulsive signal. If the subsets are different, the chains terminate and no repulsive signal is generated. The same technique has been used previously to study the type I classical cadherins, perhaps the most well-studied members of the cadherin superfamily. In the second half of this chapter, we extend our analysis to include the type II classical cadherins, which possess more complex expression patterns and binding specificities. Cryo-ET of type II cadherin ectodomains tethered to synthetic liposomes revealed that several representative members of this family form only moderately ordered arrays between liposomes, a finding in agreement with their role in cell sorting and migration. However, VE-cadherin, an outlier type II expressed in vascular endothelial cells where it withstands blood pressure, forms extraordinarily ordered junctions. Subtomogram averaging reveals the regularity of this two-dimensional array. In the final chapter, I describe my work on a membrane surface molecule of a different kind, one not involved in cell adhesion but viral infection. The global COVID-19 pandemic gave me the opportunity to contribute to our understanding of SARS-CoV-2 by studying the structure of neutralizing antibodies bound to the viral spike protein, perhaps the most infamous membrane surface protein. The first subchapter describes the initial isolation, neutralization, and structural analysis of antibodies isolated from convalescent COVID-19 patients. This work revealed that patients with severe COVID-19 produce potently neutralizing antibodies that target two spike protein domains: the receptor binding domain (RBD) and the N-terminal domain (NTD). RBD-directed antibodies occlude binding to ACE2, the human receptor that mediates viral fusion, but the neutralization mechanism of NTD-directed antibodies is unknown. The following two subchapters are more detailed structural studies of two specific types of antibodies. The first looks at a class of RBD-directed antibodies derived from the VH1-2 gene, which are some of the most potent and common antibodies against SARS-CoV-2. The heavy chains of these antibodies recognize almost identical epitopes, but the antibodies employ a modular approach to recognize the RBD in either of its possible conformations. The second class are antibodies that target the NTD, which our work revealed all bind to a single antigenic supersite. The final subchapter focuses on emerging SARS-CoV-2 variants and includes the structures of two antibodies that are still capable of neutralizing these new variants. They are also infrequent in the human antibody response to SARS-CoV-2, meaning they put little selective pressure on the virus to produce escape mutations, making them good candidates for monoclonal antibody therapies. Though Drosophila embryogenesis, adherens junction formation, and SARS-CoV-2 neutralization are seemingly unrelated systems, they are united by the incredible flexibility of cryo-EM to visualize biological molecules in more native environments. Whether it is the ability to study multiprotein complexes or assemblies formed between membranes, cryo-EM is a powerful technique that promises to help bridge the divide between structure and function.
328

Development of next-generation voltage-gated calcium channel inhibitors using engineered nanobodies

Morgenstern, Travis James January 2021 (has links)
High-voltage activated calcium channels underlie many critical functions in excitable cells and their dysfunction has been implicated in a myriad of cardiovascular and neurological diseases. These channels are multimeric protein complexes composed of α1, β, and α2δ subunits; currently, all calcium channel blockers target either the pore-forming α1 or extracellular-facing α2δ auxiliary subunit. These pharmacological agents have been invaluable in delineating the individual function of each subunit within excitable cells that express multiple calcium channels. Yet, no current tool allows similar pharmacological dissection of individual cytosolic β subunits, preventing our understanding of how distinct β subunits affect the function of calcium channel complexes. Further, small-molecule calcium channel blockers are highly-valued therapeutics for certain conditions, yet their propensity for off-target effects precludes their use in other diseases. In certain applications, genetically-encoded calcium channel blockers may enable channel inhibition with greater tissue-precision and versatility than is achievable with small molecules. Previous work that found the family of RGK proteins powerfully inhibits high-voltage activated calcium channels in part via an association with the β subunit. However, the myriad functions of RGK proteins limit the utility of this approach. In this work, we circumvent this issue by isolating single-domain antibodies (nanobodies) that target the auxiliary CaVβ subunit. We then paired these nanobodies with the powerful enzymatic activity of the HECT domain E3 ubiquitin ligase Nedd4L, to selectively target the calcium channel for ubiquitination. We found this strategy effectively eliminated functional calcium channels from the surface of HEK293 cells, myocytes, and DRG neurons. This modular design permitted us to characterize a pan-β inhibitor (CaV-aβlator) in chapter 2 while refining the approach with a β1-selective channel inhibitor in chapter 3. In chapter 4 I demonstrate that it is possible to hijack the endogenous ubiquitin machinery of the cell by creating Divas: divalent nanobodies that are capable of recruiting endogenous Nedd4L to regulate the calcium channel. Finally, we demonstrate the potential for these genetically-encoded calcium inhibitors to be employed as therapeutic agents by targeting CaV-aβlator to sensory neurons in order to reduce the onset of neuropathic pain. Altogether, this work lays the foundation for nanobody-based genetically-encoded calcium channel inhibitors that have the potential to achieve superior precision in regards to molecular and tissue specificity.
329

Expression and engineering of recombinant antibodies against a heat-shock protein of Mycobacterium bovis

Wemmer, Susan 21 October 2008 (has links)
In the medical and veterinary diagnostic fields there is an ongoing need for stable and specific antibodies. There is also a requirement for simple, robust and cost-effective diagnostic assays to be used in the developing world. Recombinant antibodies from phage displayed libraries are economical to produce and can often be engineered to improve affinity, avidity and stability. While recombinant antibody fragments are useful in immunoassays, they are not strictly comparable to normal immunoglobulins and may under-perform in certain assays. Converting monovalent single-chain antibody fragments (scFvs) to bivalent immunoglobulin-like formats could conceivably provide a more suitable molecular scaffold for use in immunoassays. Two scFvs that recognised the 65 kDa heat-shock protein (HSP65) of Mycobacterium bovis were used in this study. They were originally derived from the Nkuku® repertoire, a phage displayed antibody library based on the immune repertoire of the chicken, Gallus gallus. The genes coding for these scFvs were subcloned in expression vectors containing chicken IgY constant-heavy domains, to create bivalent constructs which were designated ‘gallibodies’. Expression of these constructs was attempted in three heterologous systems. While they were successfully produced in adherent mammalian cell cultures, the growth requirements of these cultures complicated subsequent purification. Bacteria and yeasts were investigated as alternative expression systems, but antibodies were not produced in either system. The gallibodies were compared to their monovalent scFv counterparts for stability as well as their applicability in ELISAs and gold-conjugated immunochromatographic lateral-flow assays. As gallibodies, both retained their functionality after exposure to different conditions and they were capable of immunocapture in ELISA. This was in contrast to their performance as scFvs. Furthermore, these antibody-like molecules could be stably conjugated to colloidal gold and used in lateral flow tests where positive and specific signals were obtained. This confirmed that recombinant single-chain monomeric antibody fragments could be reconstituted as bivalent immunoglobulin-like molecules and that they are a potentially useful platform for developing practical, robust immunodiagnostic reagents. It appeared from these experiments that the antibodies could act as a pair in which one captures, and the other detects HSP65. To find out whether they recognised discrete regions on the protein, their epitopes were mapped using a phage displayed peptide library in combination with computer-based algorithms. The presumptive epitope of one was mapped to residues 350 to 370 on HSP65 of M. bovis. The sequences selected from the peptide library by the other corresponded to three separate regions on the target protein. These recombinant antibody recognition sites are analogous to some of those that have been mapped by others using traditional monoclonal antibodies. / Dissertation (MSc)--University of Pretoria, 2008. / Veterinary Tropical Diseases / unrestricted
330

Intracellular delivery of rabbit monoclonal antibody

Qian, Qi 01 January 2007 (has links)
In the past decades, a series of small peptides, Protein Transduction Domain (PTD), were discovered to be able to facilitate the delivery of small proteins into living cells. With the specific feature, researchers have successfully delivered some functional proteins into living cells. To fully explore and understand the functions and structures of intracellular proteins, more powerful tools are under demand. Recently, an increasing number of rabbit monoclonal antibodies (RabMAbs) have been approved to able to recognize subtle distinctions between the changes of intracellular proteins status. They could be good tools for researchers with the ability to traverse through cell membrane into living cells. In this dissertation, a novel delivery technology for RabMAbs was established. Transcriptional activator of transcription (TAT) peptide was utilized as a delivery carrier for RabMAbs. It was demonstrated that RabMAbs could be delivered into living cells by conjugating with TAT peptide. Different cell lines, including adherent and suspension cells, were tested for the delivery of RabMAbs. The delivery process was studied in terms of incubation concentration and time, and an optimal delivery condition was established. To investigate the biological function of delivered RabMAbs inside cytoplasm, three RabMAbs against actin, procaspase-3 and NF-κB respectively were studied. Their binding activities after delivery were verified via sandwich-ELISA data. The immunofluorescent staining of the delivered RabMAb against actin showed it specifically bound to the actin filament in its native morphology. The quantitative analysis of the delivered RabMAb against procaspase-3 showed that approximately 60% of delivered antibody bound to the antigen proteins. The delivered RabMAb against NF-KB apparently blocked the nuclear translocation of NF-KB introduced by TNF-a. The success of delivering the three rabbit monoclonal antibodies with binding or inhibiting functions demonstrated the feasibility of delivering various RabMAbs into living cells by TAT peptide for studying the biological functions of intracellular proteins. Furthermore, to overcome the efficiency and cost issues of the RabMAb delivery system, a universal delivery platform for RabMAbs was developed. This platform uses goat-anti-rabbit polyclonal antibody conjugated with TAT peptide as delivery vehicle. It was confirmed that the goat-anti-rabbit polyclonal antibody modified with TAT peptide was able to capture RabMAbs and deliver RabMAbs into living cells by the conjugated TAT peptide. The results provide a promising delivery platform for all RabMAbs.

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