A produção de proteínas terapêuticas recombinantes compreende moléculas complexas e de alto valor agregado, incluindo a enzima glucocerebrosidase (GCase). Sua deficiência resulta na Doença de Gaucher, passível de tratamento por meio da terapia de reposição enzimática. A forma ativa da GCase recombinante usada na terapia apresenta resíduos terminais de manose expostos no seu perfil de glicosilação. Perfil este que espera-se ser reproduzido por meio da construção de uma linhagem de Pichia pastoris com um padrão de glicosilação humanizado, por meio da deleção de dois genes envolvidos no sistema de glicosilação da levedura: alg3 e och1, responsáveis pela posterior hiper-manosilação característica desse organismo. Assim, a expressão da GCase será usada como modelo no desenvolvimento desta linhagem de Pichia pastoris que permita a expressão de glicoproteínas com um perfil humanizado específico de glicosilação. Além da produção da linhagem mutante pela técnica de CRISPR/Cas9, propomos a construção de duas linhagens controle: uma expressando a proteína GCase para análise do seu padrão selvagem de glicosilação em P. pastoris e outra expressando a proteína Cas9 de Streptoccocus pyogenes (SpCas9). A linhagem P. pastoris/GCase foi construída testando-se duas sequências sinal de secreção diferentes: fosfatase alcalina (PHO1) e albumina humana (Alb). Resultados de western blot mostraram a GCase no lisado celular e baixos níveis de proteína secretada no sobrenadante de cultura, sendo mais expresso na linhagem contendo a sequência PHO1. A linhagem P. pastoris/SpCas9 foi construída e a enzima SpCas9 foi detectada via western blot no lisado celular após indução com metanol. Para a produção da linhagem com padrão de glicosilação humanizado propôs-se a deleção dos genes alg3 e och1 e a inserção, pela via de reparo por recombinação homóloga (HDR), de marcas de resistência aos antibióticos higromicina ou canamicina. Para tal, propusemos a construção de dois vetores finais de expressão do sistema CRISPR/Cas9 em P. pastoris, cada um contendo a enzima SpCas9 e os RNAs guia (gRNAs) para deleção do gene alg3 ou och1, e também a construção de dois fragmentos para HDR contendo o gene de resistência ao antibiótico flanqueado por regiões de 1Kb de homologia com a região de deleção do gene alg3 ou och1. A construção dos vetores e fragmentos para HDR foram inicialmente feitas por meio de técnicas de clonagem clássica. No entanto, apesar de inúmeras tentativas, resultados de PCR e sequenciamento mostraram o insucesso das construções. Partiu-se então para a técnica de Gibson Assembly®, através da qual os dois fragmentos para HDR foram construídos. Porém, os vetores de expressão contendo SpCas9 e os gRNAs ainda apresentam dificuldades na sua construção. Esforços ainda estão sendo feitos para a construção dos vetores e consequente tentativa de estabelecimento das linhagens mutantes. O sucesso no estabelecimento de um sistema de expressão de proteínas heterólogas com este padrão de glicosilação humano específico permitirá a obtenção e possível comercialização da GCase em sua forma terapêutica. Além disso, permitirá possíveis edições genômicas futuras para um padrão de maior complexidade de glicosilação humanizado, criando uma plataforma nacional para produção de outras glicoproteínas terapêuticas de interesse biotecnológico. / The production of therapeutic recombinant protein comprises complex and high valued molecules, including the glucocerebrosidase enzyme (GCase). Its deficiency results in Gaucher Disease, susceptible of treatment by enzymatic replacement therapy. The active form of recombinant GCase employed in therapy presents exposed terminal mannose residues in its glycosylation pattern. We hope to reproduce such pattern by constructing a Pichia pastoris strain with a specific human glycosylation pattern through the deletion of two genes involved in yeast glycosylation system, alg3 and och1, responsible for the final hyper-mannosylation characteristic of this organism. Therefore, the expression of GCase will be a case model for the development of the recombinant Pichia pastoris strain that could allow the expression of glycoproteins with a specific humanized glycosylation profile. Despite the establishment of the mutant strain using the CRISPR/Cas9 technique, we propose the construction of two control strains: one expressing the GCase protein for analysis of its wild type glycosylation pattern and another one expressing the Cas9 protein from Streptoccocus pyogenes (SpCas9). The P. pastoris/GCase strain was constructed testing two different secretion signal sequences: alkaline fosfatase (PHO1) and human albumin (Alb). Western blot results have shown GCase in cell lysate and in low expression levels in culture supernatant, being more expressed in the strain containing the PHO1 signal sequence. P. pastoris/SpCas9 strain was constructed and SpCas9 enzyme was detected via western blot in cell lysate after the induction with methanol. To produce the strain with the humanized glycosylation pattern, the deletion of alg3 and och1 genes was proposed along with the insertion, by homology directed repair pathway (HDR), of hygromycin and kanamycin antibiotics resistance marks. In order to do so, we have proposed the construction of two final expression vectors of the CRISPR/Cas9 system in P. pastoris, each one containing SpCas9 enzyme and the guide RNAs (gRNAs) for deletion of alg3 or och1, and also the construction of two fragments for HDR containing the antibiotics resistance gene flanked by 1Kb regions of homology with the deleted regions of alg3 or och1. Vectors and HDR fragments constructions were initially performed using classic cloning techniques. However, despite numerous tries, PCR and sequencing results have shown the failure of the constructions. Then, we moved on to the Gibson Assembly® technique, through which the two HDR fragments were built. Still, the expression vectors containing SpCas9 and the gRNAs presented difficulties in its assembly. Efforts continue to be made to successfully construct the remaining vectors and to establish the mutant lineage. Success in the establishment of a heterologous protein expression system with specific human glycosylation pattern will allow the obtainment and possible commercialization of the therapeutic form of GCase. Furthermore, it will also allow possible future genomic editing to a high complexity human glycosylation pattern, creating a national platform for the production of other therapeutic glycoproteins of biotechnological interest.

Xanthomonas oryzae pv. oryzae (Xoo), l'agent causal de bactériose vasculaire du riz (BLB), injecte des protéines de liaison à l'ADN, appelées Transcription Activator-Like Effectors (TALEs) dans les cellules hôtes afin de moduler l'expression de gènes cibles. Certains TALEs agissent comme des facteurs de virulence majeurs, indispensables à la mise en place du BLB et ciblent des gènes de sensibilité du riz. Les TALEs majeurs de Xoo ciblent universellement les gènes de sensibilité de la famille SWEET. Il existe dans la nature un polymorphisme des séquences ADN des gènes SWEET reconnues par les TALEs qui confère une résistance à la maladie. L’utilisation de la technologie TALEN a permis d'introduire artificiellement ce type de mutation dans le promoteur du gène de sensibilité SWEET14 le rendant insensible aux TALEs et conférant une résistance à certaines souches de Xoo asiatiques. La caractérisation des populations de Xoo africaines montrent qu'elles sont distinctes de celles d’Asie. L’objectif du projet de thèse était de créer à l'aide des technologies d'édition des génomes des sources de résistances efficaces contre un large panel de Xoo maliennes.Dans une première partie, l'édition des boites ADN de SWEET14 ciblées par des TALEs majeurs de souches africaines a effectivement permis d'obtenir des résistances contre les souches utilisant le TALE TalF (initialement appelé Tal5) mais pas contre celles utilisant TalC. La caractérisation du répertoire de TALEs des souches maliennes par des approches fonctionnelles (sensibilité des lignées éditées, expression de SWEET14 et autres gènes cibles de TALEs) et in silico (séquençage du génome de 8 souches) à révélé une diversité fonctionnelle de ces répertoires et la présence simultanée quasi systématique de versions actives et redondantes de TalF et TalC. La caractérisation de la sensibilité de variétés de riz locales aux souches de Xoo maliennes a montré que ces dernières possèdent un large spectre de virulence et qu'à une exception près, toutes les variétés testées sont sensibles au BLB. L'édition en multiplex par la technique CRISPR/Cas9 des boites TalF et TalC a aboli l'induction de SWEET14 en réponse à une souche malienne. Cependant, les lignées correspondantes sont restées sensibles à cette souche. Dans la dernière partie, pour expliquer ce résultat, nous avons postulé l'existence d'au moins un gène de sensibilité, cible de TalC et redondant avec SWEET14. Une approche bioinformatique a permis d'identifier un locus dont plusieurs caractéristiques en faisaient un candidat intéressant. Ce locus, nommé ATAC (pour Alternative TalC Target) est composé de deux gènes, ATAC1 et ATAC2 induits de façon bidirectionnelle par TalC. Nous avons montré qu'ATAC2, qui code pour un facteur de transcription bHLH atypique potentiellement impliqué dans l’élongation cellulaire et l'immunité chez le riz, se comporte comme un locus de sensibilité lorsqu'il est induit par des TALE artificiels dans un système gain de fonction. Nous avons édité simultanément le promoteur SWEET14 et le locus ATAC. Ces éditions devraient empêcher la reconnaissance du promoteur SWEET14 et du locus ATAC par TalC et TalF afin de conférer une résistance large au BLB au Mali. / Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial leaf blight of rice (BLB), injects DNA binding proteins called Transcription Activator-Like Effectors (TALEs) into host cells to manipulate plant genes expression. Some TALEs behave as major virulence factors essential for BLB to occur by binding directly to target DNA boxes of rice susceptibility genes and inducing their expression. Xoo major TALEs universally target susceptibility genes of the SWEET family. In nature, polymorphism in the DNA sequence of SWEET genes recognized by TALEs confers resistance to BLB. Using the TALEN technology, this type of mutations has been artificially introduced in the promoter of the SWEET14 susceptibility gene to make it TALE-unresponsive and confer resistance to some Asian Xoo. The characterizations of Malian Xoo populations show that they are distinct from the Asian ones. The PhD project aimed to create broad tailored BLB resistance against Malian Xoo using genome editing technologies.First, editing SWEET14 DNA boxes targeted by major TALEs of African strains indeed yielded resistance against strains relying on TalF (initially named Tal5) but not against those relying on TalC. The characterization of Malian strains TALE repertoires using functional (edited lines susceptibility assays, SWEET14 and other TALE target expression studies) and in silico (genome sequencing of 8 strains) approaches uncovered functional diversity in these repertoires and, the almost systematic, simultaneous presence of active and redundant versions of TalF and TalC. In susceptibility assays of local rice varieties, Malian Xoo strains exhibited a broad virulence spectrum and, with one exception, all tested varieties were susceptible to BLB. Multiplex editing of TalF and TalC target boxes with the CRISPR/Cas9 technology abolished SWEET14 induction in response to a Malian strain. However the corresponding rice lines remained susceptible to this strain. Finally, to explain these results, we postulated the existence of, at least, a TalC target susceptibility gene redundant with SWEET14. Bioinformatics analysis identified a rice locus with several features electing it as a high priority candidate. This locus named ATAC (Alternative TalC Target) is composed of two genes, ATAC1 and ATAC2, bidirectionally upregulated by TalC. We further showed that ATAC2 which is predicted to code for an atypical bHLH transcription factor potentially involved in rice cell elongation and immunity, behaves as a susceptibility gene upon artificial TALEs-mediated induction in a gain of function assay. We used the CRISPR/Cas9 system to simultaneously edit the SWEET14 promoter and the ATAC locus. These mutations should prevent the recognition of the SWEET14 promoter and the ATAC locus by TalC and TalF, compromise their transcriptional induction and ultimately provide broad BLB resistance in Mali.

La rétine est un tissu spécialisé dans le traitement de l'information visuelle par l'intermédiaire des photorécepteurs, cônes et bâtonnets, et des neurones de deuxième ordre, les cellules bipolaires et les cellules ganglionnaires dont les axones forment le nerf optique. Notre groupe s'intéresse à élucider les mécanismes génétiques impliqués dans les maladies rares stationnaires, comme dans la cécité nocturne congénitale stationnaire (CNCS), ou progressives comme dans la dystrophie de type bâtonnet-cône (DBC). Cette thèse apporte de nombreuses connaissances sur la physiologie rétinienne. D'une part, nous avons identifié GPR179, un nouveau gène impliqué dans la CNCS complète, étudié la localisation de la protéine et la physiopathologie des protéines mutantes. Nous avons également créé et caractérisé fonctionnellement un nouveau modèle souris invalidé pour GPR179 qui nous a permis de mieux approcher la première synapse rétinienne entre les photorécepteurs et les cellules bipolaires adjacentes. D'autre part, nous avons caractérisé le génotype et le phénotype de l'un des modèles les plus utilisés de la DBC, le rat P23H. Nous avons ensuite développé une approche d'édition génomique pour invalider les mutants RHO ayant un effet dominant négatif en testant in vitro, ex vivo et in vivo les meganucleases, TALEN (Transcription Activator-Like Effector Nuclease) puis le système CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR associated protein 9). / The first steps in vision occur in the retina when rod and cone photoreceptors transform light into a biochemical signal, which gets processed by bipolar cells, ganglion cells and finally by the brain. Our group investigates genetic causes and mechanisms involved in inherited stationary and progressive retinal diseases as congenital stationary night blindness (CSNB), and rod-cone dystrophy (RCD), also called retinitis pigmentosa. This thesis gives several insights on the retinal physiology. On one hand, we identified GPR179, a new gene mutated in complete CSNB, studied the localization and the physiopathology of missense and splice-site mutations. We also delivered a new knock-out mouse model which we functionally characterized, and studied GPR179 partners to provide a better understanding of the first visual synapse between photoreceptors and ON-bipolar cells. On the other hand, we genotypically and phenotypically characterized one of the most popular RCD model, the P23H rat model. There is currently no treatment for RCD and different therapeutic strategies are under investigation. We wanted to deliver the basis for a genome editing approach for RHO mutations, acting as a dominant negative effect, which cannot be addressed by current gene replacement strategies. We opened the field by performing in vitro, ex vivo and in vivo genome editing experiments using meganucleases, TALEN (Transcription Activator-Like Effector Nuclease) and finally CRISPR/Cas9 system (clustered regularly interspaced short palindromic repeats/CRISPR associated protein 9) and revealed how challenging the setting of genome editing strategies was.

CRISPR-Cas9 är ett effektivt genredigeringsverktyg som har upptäckts på senare år. Verktyget härstammar från ett adaptivt immunförsvar hos prokaryoter. Tekniken används för att modifiera DNA hos växter, djur och människor på ett enkelt och billigt sätt. CRISPR-Cas9 har visat sig ha stor potential vid bekämpning av olika sjukdomar däribland cancer som idag är ett globalt hälsoproblem. Inom cancerforskningen ses CRISPR-Cas9 som ett lovande verktyg vid cancerterapi och läkemedelsutveckling. I denna studie sammanställer vi aktuella metoder och användningsområden med CRISPR-Cas9 inom cancerforskning. Dessutom undersöker vi hur denna form av genteknik kan lyftas upp och tillämpas i biologiundervisningen. / CRISPR-Cas9 has recently emerged as an effective genome editing tool. The tool derives from an adaptive immune system in prokaryotes. The technology is used for modification of DNA in plants, animals and humans in a simple and inexpensive way. CRISPR-Cas9 has shown great potential in fighting different diseases like cancer which today is a global health issue. It is seen as a promising tool for cancer research when it comes to cancer therapy and drug development. Here we summarize current methods and applications of CRISPR-Cas9 for cancer research. Furthermore, we explore the possibilities of introducing and applying this kind of genetic engineering in biology teaching. / <p>Framläggning, opponering och respondering skedde skriftligt till följd av covid19.</p>

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22335号 / 医博第4576号 / 新制||医||1041(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 山下 潤, 教授 岩田 想, 教授 木村 剛 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

Die Rolle von Connexinen und Gap Junction-vermittelter Kommunikation in pluripotenten Stammzellen sowie der frühen Embryonalentwicklung sind bis heute nicht vollständig aufgeklärt. Mutationen in humanen Connexinen verursachen eine Vielzahl von Krankheiten. Connexin-defiziente iPS Zellen stellen eine gute Basis für die Erforschung der Rolle von Connexinen während der Embryonalentwicklung und bei der Krankheitsentstehung dar. Das Ziel der vorliegenden Arbeit war es, das CRISPR/Cas9-System in pluripotenten Stammzellen erfolgreich anzuwenden und ein Protokoll zur Erstellung verschiedener Cx43-Defektmutanten zu entwerfen. Nach der Etablierung der CRSIPR/Cas9-Methode in HEK293T-Zellen konnte in der vorliegenden Arbeit darüber hinaus erfolgreich eine Cx43-Defizienz in FSiPS-Zellen erzeugt werden. Weiterhin wurden mehrere Cx43-Mutanten geschaffen und initial auf Pluripotenzmarker und ihr Differenzierungspotential untersucht. Diese Arbeit bildet die Basis für weitere Untersuchungen des Cx43 in iPS-Zellklonen und davon abgeleiteten Zelltypen sowie artifiziellen 3D-Gewebekulturen. Darüber hinaus bildet sie die Grundlage für die Bildung weiterer Connexin-Defektmutanten sowie von iPS-Zellen mit krankheitsrelevanten Mutationen. / The roles of connexins and gap junction-mediated communication in pluripotent stem cells and early embryonic development have not been fully elucidated to date. Mutations in human connexins cause a variety of diseases. Connexin-deficient iPS cells provide a good basis for studying the role of connexins during embryonic development and in disease development. The aim of the present work was to successfully apply the CRISPR/Cas9 system in pluripotent stem cells and to design a protocol to generate different Cx43 defective mutants. Furthermore, after establishing the CRSIPR/Cas9 method in HEK293T cells, a Cx43 deficiency in FSiPS cells was successfully generated. Furthermore, several Cx43 mutants were created and initially screened for pluripotency markers and their differentiation potential. This work forms the basis for further studies of Cx43 in iPS cell clones and derived cell types as well as artificial 3D tissue cultures. Furthermore, it forms the basis for the generation of further connexin defect mutants as well as iPS cells with disease-relevant mutations.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21688号 / 医博第4494号 / 新制||医||1036(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 河本 宏, 教授 生田 宏一, 教授 江藤 浩之 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

PART I: CRYSTAL STRUCTURE OF A DIMERIZATIO DOMAIN OF DROSOPHILA CAPRIN Drosophila Melanogaster Caprin (dCaprin) shares conversed HR1 domain with Caprin protein family members, which are RNA binding proteins that play critical roles in many important biological processes, such as synaptic plasticity, stress response, innate immune response and cellular proliferation. One of the Caprin protein family members, Caprin-1, is involved in the pathway of several human diseases, including breast cancer, neurodegenerative disorders, osteosarcoma, hearing loss, and viral infection. The functions of Caprin protein relies on their molecular interactions. Several direct interactions have been established between Caprin-1 and the Fragile X mental retardation protein (FMRP), Ras-GAP SH3 domain-binding protein 1 (G3BP1), and the Japanese encephalitis virus (JEV) core protein. We have determined the crystal structures of a fragment (residues 187-309) of Drosophila Melanogaster Caprin (dCaprin), which mediates homodimerization through a substantial interface created by a mainly alpha-helical fold. A larger hollow surface is created by homodimerization suggesting a protein binding groove. The FMRP binding should not affect dCaprin homodimerization for an integral alpha-helix in the dimeric dCaprein which formed by the FMRP interacting sequence motif. PART II: CHARACTERIZATION OF TWO TYPE VI-B CRESPR SYSTEMS: PGI5CAS1B AND PGI8CAS13B WHICH EFFECTOR PROTEINS ARE CAPABLE OF PROCESSING PRE-CRRNA INTO MATURE CRRNA CRISPR-Cas adaptive immune system protects microorganism from foreign nucleic acids invasion through endonucleases activity guided by RNA, which system has turned to a powerful genome editing tool applied to a multifold species, ranging from bacteria to human. Pgi5Cas13b and Pgi8Cas13b are identified by a computational sequence database mining approach, the CRISPR arrays lack of Cas1 and Cas2 encoding genes but contain a large candidate effector protein around 1,200 amino acids. They can be potentially classified as subtype VI-B CRISPR-Cas systems. We characterized the mature crRNA for Pgi5Cas13b and Pgi8Cas13b via Northern blot and small RNA sequencing. By EMSA (Electrophoretic mobility shift assay) experiments, we identified the binding constant between Pgi5Cas1b/Pgi8Cas13b and their corresponding crRNAs. The CRISPR loci of two of the Cas13b systems were cloned in pACYC vector and expressed in E. coli cells. Small RNAs were extracted and characterized by Northern Blotting and NGS (small RNA-seq) methods. The NGS results revealed the exact sequences of the crRNAs, which show a few new features not previously observed in other systems, including the longest spacer-derived sequences (32 and 31 nt), spacer-derived sequences flanking both ends of the full DR-derived sequence. The results also indicate different rules of pre-crRNA processing by the Pgi5Cas13b and Pgi8Cas13b systems. The characterization of these CRISPR systems extends the application of CRISPR based genome editing tools and promotes the development of single transcript manipulation tools.

No description available.