No description available.

Multiple sclerosis is a neurodegenerative disorder affecting the central nervous system (CNS). Currently, the disease is incurable and immunomodulating drugs are the only option to control the disease. CD49d is an adhesion receptor expressed on most immune cells. Antibodies that bind to CD49d and block immune cells from trafficking toward the CNS are being pursued as one class of therapeutics. In this work, by combining recombinant antibody and phage display technologies we isolated 10 anti-CD49d single domain antibodies from a synthetic antibody light chain variable domain (VL) phage display library. Isolated VLs (~ 12 kDa) were expressed in Escherichia coli, purified and analysed for biophysical characteristics. The majority were expressed in good yields and were non-aggregating. All 10 VLs bound recombinant CD49d by ELISA, and 7 bound to CD49d-expressing cells in flow cytometry experiments. To empower the VLs for better therapeutic efficacy (thru increasing avidity and half-life), three of the lead VLs were re-engineered as fusions to fragment crystallisable (Fc) of human immunoglobulin gamma (IgG). The engineered hFc-VL fragments (~ 70 – 90 kDa) retained their specificity for CD49d by flow cytometry. With (i) being less immunogenic due to their human nature, (ii) their efficient access to cryptic epitopes (iii) having half-lives comparable to IgGs’ and (iv) being more cost effective compared to IgGs, these novel antibody fragments (monovalent VLs and bivalent hFc-VLs) provide a promising therapeutic platform against multiple sclerosis.

Multiple sclerosis is a neurodegenerative disorder affecting the central nervous system (CNS). Currently, the disease is incurable and immunomodulating drugs are the only option to control the disease. CD49d is an adhesion receptor expressed on most immune cells. Antibodies that bind to CD49d and block immune cells from trafficking toward the CNS are being pursued as one class of therapeutics. In this work, by combining recombinant antibody and phage display technologies we isolated 10 anti-CD49d single domain antibodies from a synthetic antibody light chain variable domain (VL) phage display library. Isolated VLs (~ 12 kDa) were expressed in Escherichia coli, purified and analysed for biophysical characteristics. The majority were expressed in good yields and were non-aggregating. All 10 VLs bound recombinant CD49d by ELISA, and 7 bound to CD49d-expressing cells in flow cytometry experiments. To empower the VLs for better therapeutic efficacy (thru increasing avidity and half-life), three of the lead VLs were re-engineered as fusions to fragment crystallisable (Fc) of human immunoglobulin gamma (IgG). The engineered hFc-VL fragments (~ 70 – 90 kDa) retained their specificity for CD49d by flow cytometry. With (i) being less immunogenic due to their human nature, (ii) their efficient access to cryptic epitopes (iii) having half-lives comparable to IgGs’ and (iv) being more cost effective compared to IgGs, these novel antibody fragments (monovalent VLs and bivalent hFc-VLs) provide a promising therapeutic platform against multiple sclerosis.

Multiple sclerosis is a neurodegenerative disorder affecting the central nervous system (CNS). Currently, the disease is incurable and immunomodulating drugs are the only option to control the disease. CD49d is an adhesion receptor expressed on most immune cells. Antibodies that bind to CD49d and block immune cells from trafficking toward the CNS are being pursued as one class of therapeutics. In this work, by combining recombinant antibody and phage display technologies we isolated 10 anti-CD49d single domain antibodies from a synthetic antibody light chain variable domain (VL) phage display library. Isolated VLs (~ 12 kDa) were expressed in Escherichia coli, purified and analysed for biophysical characteristics. The majority were expressed in good yields and were non-aggregating. All 10 VLs bound recombinant CD49d by ELISA, and 7 bound to CD49d-expressing cells in flow cytometry experiments. To empower the VLs for better therapeutic efficacy (thru increasing avidity and half-life), three of the lead VLs were re-engineered as fusions to fragment crystallisable (Fc) of human immunoglobulin gamma (IgG). The engineered hFc-VL fragments (~ 70 – 90 kDa) retained their specificity for CD49d by flow cytometry. With (i) being less immunogenic due to their human nature, (ii) their efficient access to cryptic epitopes (iii) having half-lives comparable to IgGs’ and (iv) being more cost effective compared to IgGs, these novel antibody fragments (monovalent VLs and bivalent hFc-VLs) provide a promising therapeutic platform against multiple sclerosis.

To personalize treatment for cancer, correct staging of the primary tumor, nodal disease and metastatic disease is of essence. By targeting tumor specific receptors with radiolabeled antibodies, specificity and accuracy of imaging may be improved. Radio-immunodiagnostics can potentially detect small volume disease, occult metastasis and recurrent cancer in treated tissue. This thesis focuses on evaluation of radio-immunoconjugates directed towards CD44v6, which is a surface receptor overexpressed in many head and neck squamous cell carcinomas. At the outset, the monoclonal chimeric antibody cMab U36 and its cleavage products Fab’ and F(ab’)2 were labeled with 125I and assessed in vitro and in vivo (paper I). The best distribution pattern and tumor to organ ratio was achieved with F(ab’)2. Due to the immunological responses humans can develop towards chimeric antibodies, they are not optimal for clinical use, and subsequently fully human antibody fragments were developed. AbD15179, which is a monovalent fragment, was labeled with 111In and 125I and evaluated in vitro and in mice bearing CD44v6-expressing tumors. Tumor to organ ratios were improved compared to cMab U36 derived fragments, and 111In-AbD15179 displayed a more favorable distribution compared to 125I-AbD15179 (Paper II). A bivalent Fab-dHXL, AbD19384 derived from AbD15179, was then constructed and labeled with 125I and evaluated in cell- and biodistribution studies. Furthermore, an imaging study in a small animal PET was performed with 124I-AbD19384 (Paper III). Uptake in kidneys was reduced and liver uptake increased compared to AbD15179 reflecting the larger molecule. The high CD44v6 expressing tumor was clearly visualized with maximum uptake at 48 hours post injection.In paper IV human single chain fragments towards CD44v6v were selected, and the top candidates A11 and H12 were further evaluated in vitro and in vivo. Single chain fragments are small molecules exhibiting fast clearance and high affinity to the target. The study proved this by demonstrating superior tumor to blood ratios of radiolabeled A11 and H12 compared to previously studied molecules.

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.

Resumo: A parvovirose canina, uma das principais doenças infecto-contagiosas que acomete cães, é causada pelo Parvovírus canino-2 (CPV-2). Desde sua '" escrição importantes mutações ocorreram originando três tipos: CPV-2a e 2b, comumente detectados no Brasil, e o CPV-2c. Essas alterações antígênicas caracterizam o CPV como um dos principais modelos de evolução viral, sendo etectáveis com painéis de anticorpos monoclonais em técnicas simples como hemaglutinação e neutralização in vitro. A tecnologia de apresentação de :J oteínas em bacteriófagos (Phage display) tem diversas aplicações, dentre elas a apresentação de fragmentos recombinantes de anticorpos funcionais scFv), que podem ser produzidos em grande quantidade. Este trabalho utilizou Phage Display para expressar fragmentos scFv contra o CPV-2 , com uma etodologia descrita (Krebber, 1997). Após o cultivo e purificação do vírus, camundongos da linhagem High seleção IV A foram imunizados com o CPV-2 , sendo em seguida extraído RNA total do baço. A amplificação das cadeias leve e pesada, e sua ligação por SOE-PCR, permitiu a clonagem do scFv no fagomídeo pAK 100. Após a transformação da E.coli XL-1 blue, bacteriófagos 13 foram expressos apresentando o fragmento scFv. Três processos de seleção foram realizados, e após '0 Phage-ELlSA, um grupo de fagos foi selecionado. A partir deste um screening foi realizado por PCR sendo dois lones detectados. Após nova expressão de ambos uma nova reação de Phage-ELlSA foi realizada e demonstrou a especificidade destes clones com o CPV-2. Até o presente momento esta é a primeira descrição da técnica de Phage display apresentando fragmentos de anticorpo anti-CPV-2. / Abstract: Canine parvoviral disease, one of the most common infectious disorders of dogs, is caused by canine parvovirus (CPV-2). Several mutations have accurred since it was described in the late 1970s, originating three antigenic pes: CPV-2a and 2b, most commonly found in Brazil, and the CPV-2c. These tigenic differences characterize CPV-2 as an important model of virus evolution, and could be detected by monoclonal antibody panel in hemmaglutination and in vitro neutralization. Phage display has many a plications and have been used displaying functional antibodies fragments scFv) , which can be produced in large amount. The technology described here :: the expression of antibody recombinant fragments - scFv - against CPV-2, the methodology previously described (Krebber, 1997). After cultivation and purification of virus, High IV A mice were immunized with CPV-2, total RNA s extracted from spleen cells. Light and heavy chains were amplified, and en linked by SOE-PC R; and the product was cloned into a phagemid (pAK ). After the transformation on E. coli XL-1 blue, M13 bacteriophages were - ressed presenting the scFv fragment. Series of 3 rounds of panning was ied out, and after a Phage-ELlSA a group of phage was selected. A PCR - eening was conducted and two clones detected. After new expression a age-ELlSA was performed and demonstrated the specificity of these clones against the CPV-2. Until the moment this is the first description of the use of the :J age display, producing antibody fragments against CPV-2. - / Orientador: João Pessoa Araújo Junior / Coorientador: Paulo Eduardo Martins Ribolla / Banca: Ramon Kaneno / Banca: Alice A. F. Alfieri / Banca: Hélio José Montassier / Banca: Alexandre S. Borges / Doutor

Made available in DSpace on 2014-06-11T19:32:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-02Bitstream added on 2014-06-13T19:22:35Z : No. of bitstreams: 1 batista_tn_dr_botfmvz_prot.pdf: 1218510 bytes, checksum: 40011e3f4a7d38b02ece0fb1208465c5 (MD5) / Universidade Estadual Paulista (UNESP) / A parvovirose canina, uma das principais doenças infecto-contagiosas que acomete cães, é causada pelo Parvovírus canino-2 (CPV-2). Desde sua ' escrição importantes mutações ocorreram originando três tipos: CPV-2a e 2b, comumente detectados no Brasil, e o CPV-2c. Essas alterações antígênicas caracterizam o CPV como um dos principais modelos de evolução viral, sendo etectáveis com painéis de anticorpos monoclonais em técnicas simples como hemaglutinação e neutralização in vitro. A tecnologia de apresentação de :J oteínas em bacteriófagos (Phage display) tem diversas aplicações, dentre elas a apresentação de fragmentos recombinantes de anticorpos funcionais scFv), que podem ser produzidos em grande quantidade. Este trabalho utilizou Phage Display para expressar fragmentos scFv contra o CPV-2 , com uma etodologia descrita (Krebber, 1997). Após o cultivo e purificação do vírus, camundongos da linhagem High seleção IV A foram imunizados com o CPV-2 , sendo em seguida extraído RNA total do baço. A amplificação das cadeias leve e pesada, e sua ligação por SOE-PCR, permitiu a clonagem do scFv no fagomídeo pAK 100. Após a transformação da E.coli XL-1 blue, bacteriófagos 13 foram expressos apresentando o fragmento scFv. Três processos de seleção foram realizados, e após '0 Phage-ELlSA, um grupo de fagos foi selecionado. A partir deste um screening foi realizado por PCR sendo dois lones detectados. Após nova expressão de ambos uma nova reação de Phage-ELlSA foi realizada e demonstrou a especificidade destes clones com o CPV-2. Até o presente momento esta é a primeira descrição da técnica de Phage display apresentando fragmentos de anticorpo anti-CPV-2. / Canine parvoviral disease, one of the most common infectious disorders of dogs, is caused by canine parvovirus (CPV-2). Several mutations have accurred since it was described in the late 1970s, originating three antigenic pes: CPV-2a and 2b, most commonly found in Brazil, and the CPV-2c. These tigenic differences characterize CPV-2 as an important model of virus evolution, and could be detected by monoclonal antibody panel in hemmaglutination and in vitro neutralization. Phage display has many a plications and have been used displaying functional antibodies fragments scFv) , which can be produced in large amount. The technology described here

Es ADCs (Antibody-Drug Conjugates) correspondent à une nouvelle stratégie thérapeutique anti-tumorale particulièrement prometteuse. Néanmoins, les ADCs actuellement utilisés en clinique sont obtenus par conjugaisons chimiques, resultant en des mixtures hétérogènes impactant négativement leurs pharmacocinétiques et leurs performances in vivo.Récemment, différentes strategies de couplage site-spécifique ont été développées afin de réduire cette hétérogénéité. Dans cette thèse, nous rapportons le développement d’une nouvelle technologie CovIsoLink™ (Covalently Isopeptide Crosslinking) permettant la génération d’ADCs par utilisation de nouveaux peptides glutamine Q-Tag présentant des affinités optimisées par rapport à des peptides disponibles (ZQG, LLQG) pour une enzyme bactérienne la transglutaminase (mTG).La preuve de concept de cette technologie a été réalisée par insertion de ces peptides Q-Tag en C-ter de la région codant pour la chaine lourde des anticorps anti-HER2 (Trastuzumab). Nous avons ainsi pu démontrer la conjugaison homogène et reproductible de différentes drogues sans contamination par des chaines d’anticorps non conjuguées. Nous avons pu montrer que l’immunoréactivité et la capacité d’internalisation de ces ADCs n’étaient pas altérées par la conjugaison et qu’ils présentaient in vitro et in vivo, des propriétés de lyse de cellules tumorales similaires au Trastuzumab emtansine (Kadcyla®), actuellement en clinique. Par ailleurs, afin de généraliser notre technologie à différents formats d’anticorps nous avons générés des fragments Fab et scFv et évalué leur fonctionnalité. Ainsi, nous avons pu prouver que l’utilisation de nouveaux peptides optimisés Q-Tag substrat de la transglutaminase permettait une stratégie de couplage alternative plus homogène par couplage de différentes molécules sans espèce contaminante non couplée / Antibody-drug conjugates (ADCs) are a powerful class of therapeutic agents, demonstrating success in the treatment of several malignancies. The currently approved ADCs are produced by chemical conjugations and exist as heterogeneous mixtures that negatively influence the pharmacokinetics and in vivo performance. Recently many of site-specific conjugation technologies have been developed to reduce heterogeneity and batch-to batch variability. Microbial transglutaminase (mTG) has been demonstrated as efficient tool for site-specific conjugation. In this thesis we report the development CovIsoLink™ (Covalently Isopeptide Crosslinking) technology for the generation of homogenous immunoconjugates using a novel glutamine donor peptides (Q-tag) with improved affinity compared to the known peptides (ZQG, LLQG). As a proof of concept, the peptides sequences were engineered into the heavy chain C-terminal of Trastuzumab antibody. We demonstrated the reproducible and homogeneous conjugation of Q-tagged Trastuzumab with different payloads, without any unconjugated species. The ADCs were evaluated in series of in vitro and in vivo assays. We confirmed that the immunoreactivity and internalisation are not altered by the conjugation. Furthermore similar in vitro and in vivo tumor cell killing potency was demonstrated than Trastuzumab emtansine (Kadcyla®), which is already used in the clinic. Morover we extend our site-specific conjugation technology to antibody fragments (Fab and scFv), evaluating their functionality by conjugation with AlexaFluor488-cadaverine and in antigen binding assays. Thus, using novel glutamine donor peptides, our technology provides an alternative enzymatic conjugation strategy for the engrafment of different payloads resulting in homogeneous batches, without unconjugated species

No description available.