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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.
1

Journey of Trail From Bench to Bedside and Its Potential Role in Immuno-Oncology

Naoum, George E., Buchsbaum, Donald J., Tawadros, Fady, Farooqi, Ammad, Arafat, Waleed O. 01 January 2017 (has links)
Induction of apoptosis in cancer cells has increasingly been the focus of many therapeutic approaches in oncology field. Since its identification as a TNF family member, TRAIL (TNF-related apoptosis-inducing ligand) paved a new path in apoptosis inducing cancer therapies. Its selective ability to activate extrinsic and intrinsic cell death pathways in cancer cells only, independently from p53 mutations responsible for conventional therapeutics resistance, spotted TRAIL as a potent cancer apoptotic agent. Many recombinant preparations of TRAIL and death receptor targeting monoclonal antibodies have been developed and being tested pre-clinically and clinically both as a single agent and in combinations. Of note, the monoclonal antibodies were not the only type of antibodies developed to target TRAIL receptors. Recent technology has brought forth several single chain variable domains (scFv) designs fused recombinantly to TRAIL as well. Also, it is becoming progressively more understandable that field of nanotechnology has revolutionized cancer diagnosis and therapy. The recent breakthroughs in materials science and protein engineering have helped considerably in strategically loading drugs into nanoparticles or conjugating drugs to their surface. In this review we aim to comprehensively highlight the molecular knowledge of TRAIL in the context of its pathway, receptors and resistance factors. We also aim to review the clinical trials that have been done using TRAIL based therapies and to review various scFv designs, the arsenal of nano-carriers and molecules available to selectively target tumor cells with TRAIL.
2

AC susceptibility studies under hydrostatic pressure

McCann, Duncan Michael January 2017 (has links)
AC susceptibility is an important characterisation technique measuring the time dependent magnetisation and dynamics of a magnetic system. It is capable of yielding information on thermodynamic phase transitions, relaxation processes and losses in a variety of interesting magnetic and superconducting materials. In particular it is a powerful probe of the mixed state of superconductivity providing insight into the ux dynamics at play and determination of a number of physical properties such as the critical temperature Tc, field Hc and characteristic length scales. Application of pressure can tune materials through multiple phases and interesting phenomena. The thesis describes the design of a calibratable susceptometer in a piston cylinder pressure cell, achieving AC susceptibility measurements of the same accuracy as a SQUID magnetometer but under pressure. This is used to make measurements on an electrostatically doped capacitance device, a single chain magnet and a heavy fermion superconductor. These studies are summarised below. Electric double layer (EDL) devices provide a means of continuous tuning through a materials phase diagram by applying an electric field, including inducing superconductivity. Application of pressure in tandem with electrostatic doping could improve the efficiency of these devices and provide a second tuning parameter. An EDL capacitor was constructed and measured with the above susceptometer aiming to shift the Tc of a doped high temperature superconducting cuprate La1:9Sr0:1CuO4. The Tc shifts proved irreproducible already at ambient conditions. Indeed during the course of this research further experimental evidence emerged in the literature indicating EDL devices may very well work due to electrochemical doping rather than electrostatic, possibly accounting for the lack of repeatability. Work therefore focused on mapping the ionic liquid DEME-TFSI's glass-liquid phase diagram over the 1 GPa pressure range, rather than extending the study of the EDLC device to high pressure. Single chain magnets (SCM) are an interesting class of material consisting of a one-dimensional molecular magnet chain manifesting magnetic hysteresis and slow relaxation best characterised by AC susceptibility. The susceptometer was used to study the SCM [Co(NCS)2(pyridine)2]n to investigate the effect of pressure on its characteristic magnetic relaxation time and energy barrier. A secondary signal appears at ~0.44 GPa which is attributed to the development of an additional structural phase that has been independently observed in X-ray crystallographic measurements. The heavy fermion superconductor U6Fe has the highest Tc ~4 K of all the U-based compounds and large critical fields of ~10-12.5 T, depending on direction, which increase on initial application of pressure. It exhibits a coexisting charge density wave (CDW) below 10 K making it a promising candidate for the modulated superconductivity of the theorised Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) state. A feature at 110 K is also evident in Mossbauer, resistivity and specific heat measurements, the origin of which has not yet been clearly identified. Evidence for the FFLO state was sought by mapping the upper critical field Hc2 along with the peak effect through AC susceptibility measurements up to pressures of 1 GPa. The data is accounted for by an evolution of collective pinning and superconducting parameters, with no clear evidence for an FFLO state although an enhancement of the reduced field is observed.
3

Undersökning av affinitet till TS1-218, TS1-218<sub>2</sub> och HE1-Q enkelkedjeantikroppar i multicellulära tumörsfäroider cytokeratin 8 för TS1-218, TS1-218<sub>2</sub> och HE1-Q enkelkedjeantikroppar i multicellulära tumörsfäroider / Investigation of affinity to cytokeratin 8 in multicellular tumor spheroids for TS1-218, TS1-218<sub>2</sub> and HE1-Q single chain variable fragment antibodies

Piercecchi, Marco January 2009 (has links)
<p>In vitro-test för upptäckt och behandling av tumör eller mikrometastaser har de senaste 30 åren gjort stora framsteg tack vare immunokemi och nya framgångsrika cellodlings- tekniker som bättre reproducerar celltillväxt i tre dimensioner (3D) och det omgivande stromat (multicellulär tumörsfäroidodling). TS1-218 scFv (single chain variable fragment) är en monoklonal antikropp som har affinitet till ett protein tillhörande cytoskelettet (cytokeratin). Av TS1-218 har skapats olika varianter (en dimer TS1-218<sub>2</sub> och en mutant HE1-Q) med syftet att öka affinitet och retentionstid på platsen för dess verkan. I det här projektet försökte vi att testa och jämföra egenskaper hos alla 3 joderade antikropparna genom att inkubera odlade Hela Hep 2 tumörcellssfäroider med dessa antikroppar. Alla tre antikroppsvarianter visade god förmåga att penetrera sfäroider och att binda deras epitop i cytokeratin 8. Försöken visade att det fanns affinitetsskillnader mellan TS1-218 monomer, dimer och mutant vilket visade sig som olika inbindningsförmåga till sfäroiderna.</p>
4

Undersökning av affinitet till TS1-218, TS1-2182 och HE1-Q enkelkedjeantikroppar i multicellulära tumörsfäroider cytokeratin 8 för TS1-218, TS1-2182 och HE1-Q enkelkedjeantikroppar i multicellulära tumörsfäroider / Investigation of affinity to cytokeratin 8 in multicellular tumor spheroids for TS1-218, TS1-2182 and HE1-Q single chain variable fragment antibodies

Piercecchi, Marco January 2009 (has links)
In vitro-test för upptäckt och behandling av tumör eller mikrometastaser har de senaste 30 åren gjort stora framsteg tack vare immunokemi och nya framgångsrika cellodlings- tekniker som bättre reproducerar celltillväxt i tre dimensioner (3D) och det omgivande stromat (multicellulär tumörsfäroidodling). TS1-218 scFv (single chain variable fragment) är en monoklonal antikropp som har affinitet till ett protein tillhörande cytoskelettet (cytokeratin). Av TS1-218 har skapats olika varianter (en dimer TS1-2182 och en mutant HE1-Q) med syftet att öka affinitet och retentionstid på platsen för dess verkan. I det här projektet försökte vi att testa och jämföra egenskaper hos alla 3 joderade antikropparna genom att inkubera odlade Hela Hep 2 tumörcellssfäroider med dessa antikroppar. Alla tre antikroppsvarianter visade god förmåga att penetrera sfäroider och att binda deras epitop i cytokeratin 8. Försöken visade att det fanns affinitetsskillnader mellan TS1-218 monomer, dimer och mutant vilket visade sig som olika inbindningsförmåga till sfäroiderna.
5

Desenvolvimento de novos vetores para a produção de bibliotecas de anticorpos pelo sistema do phage display / Development of a antibody display library system targeted against vascular growth factor

Gomes, Carlos Henrique Rodrigues 23 November 2018 (has links)
Anticorpos são moléculas de grande interesse científico e farmacêutico, principalmente, devido a sua alta especificidade contra antígenos determinados. Atualmente, anticorpos monoclonais estão entre os medicamentos (biofármacos) mais vendidos do mundo. São utilizados para o tratamento das mais diversas doenças, como câncer, retinopatias, doenças inflamatórias e do sistema imune, entre outras. Nos últimos 30 anos, as tecnologias para a obtenção de anticorpos monoclonais evoluíram muito, desde a tecnologia do hibridoma, até os processos de humanização de anticorpos murinos. Entre os métodos mais utilizados para a produção de anticorpos humanos, destaca-se a tecnologia do Phage Display. Nesta técnica, os genes que codificam as regiões variáveis de imunoglobulinas são inseridos no genoma de um bacteriófago, resultando na produção de partículas virais híbridas que contém fragmentos de anticorpos em fusão com uma das proteínas do capsídeo viral. Neste trabalho, desenvolvemos novos vetores para a apresentação de fragmentos ScFv em fusão com duas proteínas das proteínas do capsídeo viral, a pIII e pVIII. Os oligonucleotídeos utilizados para amplificar os genes de imunoglobulinas foram redesenhados e para minimizar a perda do repertório durante a produção da biblioteca, avaliamos em bancos de dados enzimas de restrição que não apresentam sítios de restrição nas sequencias gênicas. Esses sítios de restrição foram utilizados para construir as regiões de clonagem do vetor Phagemid. Outra etapa crítica na produção de bibliotecas de anticorpos é a reação do PCR de overlap, que pode restringir a diversidade de anticorpos e resultar na produção de amplicons codificando anticorpos truncados. Por isso, nossos vetores foram desenhados para permitir a clonagem direta das regiões variáveis das imunoglobulinas humanas ou murinas, sem a necessidade do PCR de overlap. Nossa expectativa, é que estes novos reagentes serão mais efetivos para a produção de novas bibliotecas de anticorpos pelo sistema do Phage Display. / Antibodies are molecules of great scientific and pharmaceutical interest, mainly because of their high specificity against certain antigens. Currently, monoclonal antibodies are among the best selling drugs (biopharmaceuticals) in the world. They are used for the treatment of the most diverse disorders, such as cancer, retinopathies, inflammatory and immune system diseases, among others. In the past 30 years, technologies for obtaining monoclonal antibodies has greatly evolved from hybridoma technology to the humanization processes of murine antibodies. Among the methods used for the production of human antibodies, the technology of Phage Display stands out. In this technique, the genes encoding the immunoglobulin variable regions are inserted into the genome of a bacteriophage, resulting in the production of hybrid virus particles which contain fragments of antibodies in fusion with one of the viral capsid proteins. In this work, we developed new vectors for the presentation of ScFv fragments in fusion with two proteins of viral capsid proteins, pIII and pVIII. The oligonucleotides used to amplify the immunoglobulin genes were redesigned and to minimize repertory loss during library production, we evaluated restriction enzymes in databases that lack restriction sites in the gene sequences. These restriction sites were used to construct the cloning regions of the Phagemid vector. Another critical step in the production of antibody libraries is the overlap PCR reaction, which may restrict the diversity of antibodies and result in the production of amplicons encoding truncated antibodies. Therefore, our vectors were designed to allow the direct cloning of human or murine Immunoglobulins variable regions without the need for overlap PCR. Our expectation is that these new reagents will be more effective for the production of new antibody libraries by the Phage Display system.
6

Single-chain insulin analogs as ultra-stable therapeutics and as models of protein (mis)folding: stability, structure, dynamics, and function of novel analogs

Glidden, Michael D., II 31 May 2018 (has links)
No description available.
7

Functional mapping and in vivo metabolism of the monoclonal antibody TS1 and its single-chain fragment : Its interaction with the antigen and the anti-idiotype

Holm, Patrik January 2006 (has links)
<p>Antibodies are proteins capable of specific interactions to a wide range of molecules. These interactions are facilitated by the complementary determining regions (CDR).</p><p>Carcinomas are the most common of human cancers and they release significant amount of cytokeratins (CK) in the necrotic areas of the tumors. The CKs stay in the tumor, since they have low solubility. The antibody studied in this thesis, the anti-CK 8 antibody TS1, has shown to be effective in tumor targeting and is proposed to be useful in therapy.</p><p>Single-chain antibodies (scFv) are recombinant antibodies which are much smaller than the intact IgG. This is an advantage when used in tumor therapy, since they can penetrate the tumors more easily than the larger IgG. Moreover, they are expressed by one single gene which make them easy to modify, for example by site-directed mutagenesis.</p><p>The anti-idiotypic antibody αTS1 can be used to clear the TS1 form the circulation and thereby clear the body from non-tumor bound TS1 in therapy. To be able to modify the binding of an antibody to its antigen and or anti-idiotype, these interactions must be studied. In this study this is accomplished by chemical modifications of the IgGs TS1 and αTS1 and the antigen CK 8. Guided by these results, amino acid residues were mutated by using site-directed mutagenesis in the TS1-218 scFv and the effects were studied. From mutational study results, the functional epitope could be mapped and it was found that there are mainly tyrosines, but also charged residues, serine and a tryptophan that are important for both interactions. The binding of TS1-218 to both αTS1 and CK 8 could be improved by changing the negatively charged side-chains by mutations to their corresponding amide or alanine.</p><p>Both the IgG and scFv versions of TS1 were administered in vivo. The IgG αTS1 was used to clear the TS1 from the circulation by forming immune complexes. The immune complexes, consisting of four or more antibodies, were mainly metabolized by the liver. The scFv TS1-218 could localize to the tumor in a tumor xenograft mouse model, although a higher uptake would be desired in a therapeutic strategy. The scFv was cleared rapidly by the kidneys, but the clearance could be slowed by pre-formed immune complexes with anti-TS1 scFv in vitro, prior to administration in vivo.</p>
8

Design and Optimization of Recombinant Antibodies Directed Against Platelet Glycoprotein VI with Therapeutic and Diagnostic Potentials / Conception et optimisation d'anticorps recombinants à potentiel thérapeutique et diagnostique, dirigés contre la Glycoprotéine VI (GPVI) plaquettaire

Zahid, Muhammad 24 November 2011 (has links)
La glycoprotéine VI (GP VI) des plaquettes sanguines humaines est le récepteur principal du collagène, composé le plus thrombogénique d'une paroi vasculaire lésée. Ainsi, GPVI est souvent considérée comme une cible de premier plan pour développer des tests diagnostiques ou des stratégies thérapeutiques innovantes, efficaces et sûres afin d'améliorer encore la prise en charge des accidents ischémiques. Les anticorps monoclonaux et leurs fragments actifs produits par ingénierie moléculaire constituent aujourd'hui une nouvelle classe de biomolécules en plein essor avec des propriétés bien adaptées à des applications thérapeutiques et diagnostiques. Notre groupe a produit plusieurs anticorps monoclonaux anti-GPVI par immunisation génique de souris. Ces anticorps ont une affinité élevé pour leur cible. Ils de distinguent les uns des autres par leur spécificité épitopique ainsi que par les effets engendrés par leur liaison à GPVI. Parmi ces anticorps, l'un présente un fort potentiel diagnostique parce qu'il reconnait les formes mono- et dimériques de GPVI, mais sa liaison aux plaquettes peut induire une activation ou la perte de GPVI. Un autre anticorps présente un fort potentiel thérapeutique parce que ses fragments actifs monovalents obtenus par papaïnolyse neutralisent l'interaction entre les plaquettes et le collagène, sans activer les plaquette. Cependant, l'origine xénogénique de cet anticorps est responsable d'une forte immunogénicité qui en interdit des applications en médecine humaine. Dans cette étude, nous avons conçus un fragments variable d'anticorps simple chaine (scFv) utile pour quantifier l'expression de la GPVI à la surface des plaquettes sanguines. Ce scFv a été reformaté de façon à lui insérer un motif de reconnaissance de la Protéine L (PpL) qui facilite sa détection et sa purification sans avoir recours à un peptide "drapeau". Nous avons également humanisé et créé plusieurs fragments d'anticorps recombinants monovalents inhibiteurs de l'interaction GPVI / collagène. Ces fragments d'anticorps présentent un potentiel thérapeutique élevé. / Human platelets glycoprotein VI (GPVI) is evidenced to be a platelet receptor of major importance in the occurrence of arterial thrombosis. Thus, it can be considered to be of great interest in diagnosis and therapeutic of atheriosclerotic diseases. Antibodies are powerful molecules which can be used in both diagnostic as well as for therapeutic purposes due to their unique characteristics. Monoclonal and recombinant antibodies have antigen restricted specificity, high affinity and can be used in various assays. Moreover, the good knowledge of their structure and molecular engineering facilities now allows the antibody modulation according to desired properties.Our group has already produced several monoclonal antibodies to human GPVI by gene gun immunization against the immunoadhesin hGPVI-Fc, which differ in fine epitopespecificity, affinity and other functional properties (Lecut et al. 2003). One, 3J24, with diagnostic potential while the other, 9O12, has a therapeutic potential because it blocks the binding of GPVI to collagen. Its Fab fragment has been extensively characterized in vitro,ex vivo and in vivo for its antithrombotic properties.Here, we designed and reshaped a single-chain antibody fragment (scFv) based on 3J24variable domains for the quantification of GPVI with diagnostic potential. We were also involved in the design, production and functional evaluation of humanized anti-GPVI recombinant antibody fragments (scFvs and Fabs) with therapeutic properties.
9

Development and characterization of Mantle Cell Lymphoma specific IgGs

Gärdefors, Katarina January 2008 (has links)
Mantle cell lymphoma (MCL) is one of several sub-types of B-cell lymphomas. The malignancy is very aggressive and average survival time is short. The hallmark of MCL is over expression of cyclin D1, however about 15% of all MCL cases do not display this over expression and are easily misdiagnosed. Recently the transcription factor Sox11 has been shown to be specifically over expressed in the nucleus of MCL-tumour cells, and polyclonal rabbit anti-Sox11 antibodies have been used to successfully identify MCL in both cyclin D1 positive and negative cases. Howev-er, human recombinant MCL-specific antibodies as have several advantages over these polyclonal rabbit antibodies; they can easily be produced in large quantities in vitro, their specificity is constant from batch to batch and they can possibly be used for therapeutic purposes. Because of this, it is desirable to produce human recombinant antibodies against proteins over expressed in MCL. In this study human recombinant IgGs have been produced towards two pro-teins over expressed in MCL, Sox11 and KIAA0882. This was done by cloning of single chain variable fragments (scFvs), previously selected from a large scFv library through phage display selection against Sox11- and KIAA0882-protein epitope signature tag (PrEST), into vectors containing human IgG constant regions followed by expression of human IgG antibodies in human embryonic kidney (HEK) 293 cells. One IgG clone for each antigen was shown to be functional and specific. Both clones were shown to have overlapping binding epitopes with their polyclonal rabbit antibody counterpart (rabbit anti-Sox11/KIAA0882) through competitive ELISA. The anti-Sox11 IgG was able to detect two bands in cell lysate in Western blot, of which one probably is Sox11 while the other band possibly could be Sox4. However, this needs to be confirmed in future experiments. The affinity of the anti-Sox11 IgG was measured in Biacore and compared to the affinity of its original scFv. This gave a rough estimation of the affinities, but the values are unreliable and the measurements need to be redone. Although more work has to be put into evaluating the potential of the produced IgGs, they compose a promising starting point to an improved understanding and improved diagnosis of MCL.
10

Development and characterization of Mantle Cell Lymphoma specific IgGs

Gärdefors, Katarina January 2008 (has links)
<p>Mantle cell lymphoma (MCL) is one of several sub-types of B-cell lymphomas. The malignancy is very aggressive and average survival time is short. The hallmark of MCL is over expression of cyclin D1, however about 15% of all MCL cases do not display this over expression and are easily misdiagnosed. Recently the transcription factor Sox11 has been shown to be specifically over expressed in the nucleus of MCL-tumour cells, and polyclonal rabbit anti-Sox11 antibodies have been used to successfully identify MCL in both cyclin D1 positive and negative cases. Howev-er, human recombinant MCL-specific antibodies as have several advantages over these polyclonal rabbit antibodies; they can easily be produced in large quantities in vitro, their specificity is constant from batch to batch and they can possibly be used for therapeutic purposes. Because of this, it is desirable to produce human recombinant antibodies against proteins over expressed in MCL. In this study human recombinant IgGs have been produced towards two pro-teins over expressed in MCL, Sox11 and KIAA0882. This was done by cloning of single chain variable fragments (scFvs), previously selected from a large scFv library through phage display selection against Sox11- and KIAA0882-protein epitope signature tag (PrEST), into vectors containing human IgG constant regions followed by expression of human IgG antibodies in human embryonic kidney (HEK) 293 cells. One IgG clone for each antigen was shown to be functional and specific. Both clones were shown to have overlapping binding epitopes with their polyclonal rabbit antibody counterpart (rabbit anti-Sox11/KIAA0882) through competitive ELISA. The anti-Sox11 IgG was able to detect two bands in cell lysate in Western blot, of which one probably is Sox11 while the other band possibly could be Sox4. However, this needs to be confirmed in future experiments. The affinity of the anti-Sox11 IgG was measured in Biacore and compared to the affinity of its original scFv. This gave a rough estimation of the affinities, but the values are unreliable and the measurements need to be redone. Although more work has to be put into evaluating the potential of the produced IgGs, they compose a promising starting point to an improved understanding and improved diagnosis of MCL.</p>

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