RESUMO
ABSTRACT: Gene therapy using adeno-associated virus (AAV) vectors is a promising approach for the treatment of monogenic disorders. Long-term multiyear transgene expression has been demonstrated in animal models and clinical studies. Nevertheless, uncertainties remain concerning the nature of AAV vector persistence and whether there is a potential for genotoxicity. Here, we describe the mechanisms of AAV vector persistence in the liver of a severe hemophilia A dog model (male = 4, hemizygous; and female = 4, homozygous), more than a decade after portal vein delivery. The predominant vector form was nonintegrated episomal structures with levels correlating with long-term transgene expression. Random integration was seen in all samples (median frequency, 9.3e-4 sites per cell), with small numbers of nonrandom common integration sites associated with open chromatin. No full-length integrated vectors were found, supporting predominant episomal vector-mediated long-term transgene expression. Despite integration, this was not associated with oncogene upregulation or histopathological evidence of tumorigenesis. These findings support the long-term safety of this therapeutic modality.
Assuntos
Dependovirus , Fator VIII , Terapia Genética , Vetores Genéticos , Hemofilia A , Fígado , Animais , Cães , Dependovirus/genética , Hemofilia A/genética , Hemofilia A/terapia , Vetores Genéticos/genética , Fígado/metabolismo , Fígado/patologia , Masculino , Terapia Genética/métodos , Feminino , Fator VIII/genética , Técnicas de Transferência de Genes , Integração Viral , Transgenes , Modelos Animais de DoençasRESUMO
BACKGROUND: Glarea lozoyensis is a filamentous fungus used for the industrial production of non-ribosomal peptide pneumocandin B0. In the scope of a whole genome sequencing the complete mitochondrial genome of the fungus has been assembled and annotated. It is the first one of the large polyphyletic Helotiaceae family. A phylogenetic analysis was performed based on conserved proteins of the oxidative phosphorylation system in mitochondrial genomes. RESULTS: The total size of the mitochondrial genome is 45,038 bp. It contains the expected 14 genes coding for proteins related to oxidative phosphorylation,two rRNA genes, six hypothetical proteins, three intronic genes of which two are homing endonucleases and a ribosomal protein rps3. Additionally there is a set of 33 tRNA genes. All genes are located on the same strand. Phylogenetic analyses based on concatenated mitochondrial protein sequences confirmed that G. lozoyensis belongs to the order of Helotiales and that it is most closely related to Phialocephala subalpina. However, a comparison with the three other mitochondrial genomes known from Helotialean species revealed remarkable differences in size, gene content and sequence. Moreover, it was found that the gene order found in P. subalpina and Sclerotinia sclerotiorum is not conserved in G. lozoyensis. CONCLUSION: The arrangement of genes and other differences found between the mitochondrial genome of G. lozoyensis and those of other Helotiales indicates a broad genetic diversity within this large order. Further mitochondrial genomes are required in order to determine whether there is a continuous transition between the different forms of mitochondrial genomes or G. lozoyensis belongs to a distinct subgroup within Helotiales.
Assuntos
Ascomicetos/genética , Variação Genética , Genoma Fúngico/genética , Genoma Mitocondrial/genética , Filogenia , Mapeamento Cromossômico , Códon/genética , Proteínas Fúngicas/metabolismo , Ordem dos Genes , Genes Fúngicos/genética , Código Genético , Íntrons/genética , Proteínas Mitocondriais/metabolismo , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , RNA de Transferência/genéticaRESUMO
The anamorphic fungus Glarea lozoyensis mutant strain 74030 is an overproducer of pneumocandin B(0), which is chemically converted into Cancidas, a potent antibiotic against clinically important fungal pathogens. Pneumocandins are acylated, cyclic hexapeptides with unusual hydroxylated amino acids. With the Glarea lozoyensis genome, the first species from the large polyphyletic family Helotiaceae has been sequenced.