STUDIES ON BIOLOGICAL CONTROL AND MASS PRODUCTION OF EGGS AND LARVAE OF TOXORHYNCHITES SPLENDENS

Bachelor'sBACHELOR OF SCIENCE (HONOURS

Role of nef in HIV-1 gene regulation

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

BIOLOGY OF TOXORHYNCHITES SPLENDENS (DIPTERA, CULICIDAE) IN RELATION NUTRITION

Master'sMASTER OF SCIENC

Hemophilia Gene Therapy: Ready for Prime Time?

Hemophilia A and B are congenital, X-linked bleeding disorders caused by mutations in the genes encoding for the blood clotting factor VIII (FVIII) or factor IX (FIX), respectively. Since the beginning of gene therapy, hemophilia has been considered an attractive disease target that served as a trailblazer for the field at large. Different technologies have been explored to efficiently and safely deliver the therapeutic FVIII and FIX genes into the patients' cells. Currently, the most promising vectors for hemophilia gene therapy are adeno-associated viral vectors (AAVs) and lentiviral vectors. More recently, gene editing approaches based on designer nucleases or CRISPR/Cas, have also been considered to minimize risks associated with random vector integration and insertional mutagenesis though off-target issues would have to be carefully and comprehensively assessed. In the past two decades, several phase 1 hemophilia gene therapy clinical trials have been initiated with varying success. In particular, the early gene therapy clinical trials in hemophilia B patients based on AAV showed either transient or subtherapeutic clotting factor expression levels. This could be ascribed, at least in part, to suboptimal vector design and/or inadvertent immune consequences triggering hepatic inflammation. Hence, there was an unmet need to further increase vector safety and efficacy in future trials, preferably by using lower vector doses. It is particularly encouraging that sustained therapeutic FVIII and FIX expression levels have recently been attained after gene therapy in patients with severe hemophilia paving the way towards pivotal trials and commercialization. Nevertheless, transient liver toxicity still occurs and the use of transient immunosuppression was still required to curtail inadvertent immune responses, especially at high vector doses. To further boost clotting factor expression levels, codon-usage optimized synthetic FVIII or FIX transgenes have been employed. Alternatively, we and others have shown that the incorporation of hyperactive gain-of-function R338L mutation in the FIX gene substantially increased the overall efficacy. It is inevitable that the continued improvements in vector engineering and new insights in the vector-patient interactions will further benefit the development of a safe and effective cure for hemophilia A and B.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Platelet-directed gene therapy overcomes inhibitory antibodies to factor VIII

SCOPUS: no.jFLWINinfo:eu-repo/semantics/publishe

Clinical progress in gene therapy: Sustained partial correction of the bleeding disorder in patients suffering from severe hemophilia B

SCOPUS: no.jinfo:eu-repo/semantics/publishe

Optimizing delivery and expression of designer nucleases for genome engineering

Genome engineering can be accomplished by designer nucleases. They are specifically designed to cleave double-stranded DNA at the desired target locus. This double-strand break subsequently engages the DNA repair pathway through nonhomologous end-joining (NHEJ), resulting in either gene disruption or gene repair. Alternatively, the presence of homologous donor DNA allows for targeted integration of this exogenous donor DNA in this target locus through homology-directed DNA repair. The key bottleneck in genome engineering relates to the delivery and expression of the designer nucleases. One of the most attractive vector platforms for genome engineering is based on integration-defective lentiviral vectors (IDLVs). The intrinsic episomal nature of IDLVs is well suited to ensure transient expression of designer nucleases and minimize potential risks associated with their sustained expression. Unfortunately, their expression is compromised because of epigenetic silencing that interferes with the transcriptional competence of IDLVs. In this issue, Pelascini and colleagues now showed that this bottleneck could be overcome by interfering with chromatin remodeling using histone deacetylase (HDAC) inhibitors. HDAC inhibition restored expression of designer nucleases from IDLVs and rescued their ability to achieve efficient targeted gene disruption by NHEJ comparable with that achieved with bona fide integrating lentiviral vectors. This study has implications for the ex vivo use of IDLVs for gene repair and gene targeting. © Mary Ann Liebert, Inc.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Hitting the target without pulling the trigger

SCOPUS: no.jinfo:eu-repo/semantics/publishe

Targeting endothelial cells by gene therapy

In this issue of Blood, Abel et al designed lentiviral vectors (LVs) enabling specific gene delivery into endothelial cells in vivo. This opens new perspectives for gene therapy of hereditary disorders, cardiovascular diseases, and cancer. 1 © 2013 by The American Society of Hematology.SCOPUS: no.jinfo:eu-repo/semantics/publishe

Recent progress in gene therapy for hemophilia

Hemophilia A and B are X-linked monogenic disorders caused by deficiencies in coagulation factor VIII (FVIII) and factor IX (FIX), respectively. Current treatment for hemophilia involves intravenous infusion of clotting factor concentrates. However, this does not constitute a cure, and the development of gene-based therapies for hemophilia to achieve prolonged high level expression of clotting factors to correct the bleeding diathesis are warranted. Different types of viral and nonviral gene delivery systems and a wide range of different target cells, including hepatocytes, skeletal muscle cells, hematopoietic stem cells (HSCs), and endothelial cells, have been explored for hemophilia gene therapy. Adeno-associated virus (AAV)-based and lentiviral vectors are among the most promising vectors for hemophilia gene therapy. Stable correction of the bleeding phenotypes in hemophilia A and B was achieved in murine and canine models, and these promising preclinical studies prompted clinical trials in patients suffering from severe hemophilia. These studies recently resulted in the first demonstration that long-term expression of therapeutic FIX levels could be achieved in patients undergoing gene therapy. Despite this progress, there are still a number of hurdles that need to be overcome. In particular, the FIX levels obtained were insufficient to prevent bleeding induced by trauma or injury. Moreover, the gene-modified cells in these patients can become potential targets for immune destruction by effector T cells, specific for the AAV vector antigens. Consequently, more efficacious approaches are needed to achieve full hemostatic correction and to ultimately establish a cure for hemophilia A and B. © 2012, Mary Ann Liebert, Inc.SCOPUS: ar.jinfo:eu-repo/semantics/publishe