RESUMO
Until recently, adeno-associated virus 9 (AAV9) was considered the AAV serotype most effective in crossing the blood-brain barrier (BBB) and transducing cells of the central nervous system (CNS), following systemic injection. However, a newly engineered capsid, AAV-PHP.B, is reported to cross the BBB at even higher efficiency. We investigated how much we could boost CNS transgene expression by using AAV-PHP.B carrying a self-complementary (sc) genome. To allow comparison, 6 weeks old C57BL/6 mice received intravenous injections of scAAV2/9-GFP or scAAV2/PHP.B-GFP at equivalent doses. Three weeks postinjection, transgene expression was assessed in brain and spinal cord. We consistently observed more widespread CNS transduction and higher levels of transgene expression when using the scAAV2/PHP.B-GFP vector. In particular, we observed an unprecedented level of astrocyte transduction in the cortex, when using a ubiquitous CBA promoter. In comparison, neuronal transduction was much lower than previously reported. However, strong neuronal expression (including spinal motor neurons) was observed when the human synapsin promoter was used. These findings constitute the first reported use of an AAV-PHP.B capsid, encapsulating a scAAV genome, for gene transfer in adult mice. Our results underscore the potential of this AAV construct as a platform for safer and more efficacious gene therapy vectors for the CNS.
Assuntos
Astrócitos/metabolismo , Encéfalo/metabolismo , Dependovirus/genética , Vetores Genéticos/administração & dosagem , Neurônios/metabolismo , Transdução Genética , Animais , Encéfalo/citologia , Feminino , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Camundongos Endogâmicos C57BL , Regiões Promotoras Genéticas , Sinapsinas/genética , TransgenesRESUMO
Activated leukocyte cell adhesion molecule (ALCAM) is a type I transmembrane protein member of the immunoglobulin superfamily of cell adhesion molecules. Involved in important pathophysiological processes such as the immune response, cancer metastasis, and neuronal development, ALCAM undergoes both homotypic interactions with other ALCAM molecules and heterotypic interactions with the surface receptor CD6 expressed at the T cell surface. Despite biochemical and biophysical evidence of a dynamic association between ALCAM and the actin cytoskeleton, no detailed information is available about how this association occurs at the molecular level. Here, we exploit a combination of complementary microscopy techniques, including FRET detected by fluorescence lifetime imaging microscopy and single-cell force spectroscopy, and we demonstrate the existence of a preformed ligand-independent supramolecular complex where ALCAM stably interacts with actin by binding to syntenin-1 and ezrin. Interaction with the ligand CD6 further enhances these multiple interactions. Altogether, our results propose a novel biophysical framework to understand the stabilizing role of the ALCAM supramolecular complex engaged to CD6 during dendritic cell-T cell interactions and provide novel information on the molecular players involved in the formation and signaling of the immunological synapse at the dendritic cell side.
Assuntos
Citoesqueleto de Actina/metabolismo , Antígenos CD/metabolismo , Moléculas de Adesão Celular Neuronais/metabolismo , Comunicação Celular/fisiologia , Proteínas do Citoesqueleto/metabolismo , Células Dendríticas/metabolismo , Proteínas Fetais/metabolismo , Sinteninas/metabolismo , Linfócitos T/metabolismo , Citoesqueleto de Actina/genética , Animais , Antígenos CD/genética , Antígenos de Diferenciação de Linfócitos T/genética , Antígenos de Diferenciação de Linfócitos T/metabolismo , Moléculas de Adesão Celular Neuronais/genética , Proteínas do Citoesqueleto/genética , Células Dendríticas/citologia , Proteínas Fetais/genética , Humanos , Células K562 , Camundongos , Ligação Proteica , Sinteninas/genética , Linfócitos T/citologiaRESUMO
Screening for genetic diversity in livestock species breeds is of utmost importance, especially for local, small populations that are at the risk of extinction. Luckily, recent developments in technology increase access to genotyping, also for numerically small breeds. One of these new technologies is the IMAGE001 single nucleotide polymorphism genotyping array that includes markers for 6 different species (cow, pig, sheep, chicken, horse and goat). For our current study, we studied the Turkey-headed Malines chicken, a local chicken breed in Belgium, for the first time. A total of 110 animals were genotyped, together with 29 samples from 4 supposedly related breeds. The genotypes were used to assess the genetic diversity of this local breed. Our analysis revealed an average inbreeding coefficient of 0.20 through runs of homozygosity analysis, and effective population size estimation based on linkage disequilibrium indicated a low genetic diversity (Ne = 34). Moreover, a principal component analysis and a genetic differentiation study (FST) were performed using these marker data to position the Turkey-headed Malines relative to the 4 other indigenous Belgian chicken breeds. Finally, we discussed the practical implications of the overlap between the IMAGE001 array and other existing chicken genotyping arrays. This study is the first use of the novel IMAGE001 array to evaluate a local chicken breed, and demonstrates it as a viable option for genomic characterization a breed. Moreover, with this research, we are able to provide a good basis for further evaluation of the Belgian chicken heritage.