Canine G-CSF gene transfer

描述（由申请方提供）：周期性中性粒细胞减少症是一种罕见的疾病，发生在人和灰色牧羊犬中。反复发作的严重中性粒细胞减少症导致细菌感染和预期寿命缩短。长期每日给予重组G-CSF消除了严重的复发性中性粒细胞减少症，并为犬和患者提供了治疗。本研究将研究使用两种不同的方法通过递送G-CSF治疗具有循环造血的灰色牧羊犬。在一个目标，我们将研究在体内慢病毒介导的犬G-CSF的交付。在另一个目标中，G-CSF将通过在生物隔离装置中采用转导的同种异体细胞的细胞植入物递送，这消除了对免疫抑制的需要。我们以前已经表明，长期给予重组犬G-CSF消除了受影响犬的复发性造血循环，并且我们有数据显示，给予编码犬G-CSF的慢病毒的受影响犬的中性粒细胞产生增加。我们将给予G-CSF编码慢病毒的灰色牧羊犬和正常的狗和大鼠的肌肉。我们将研究在生物隔离装置中植入转导的血管平滑肌细胞，以在大鼠、正常犬和灰色牧羊犬中提供安全的G-CSF长期表达。选择这些靶细胞是为了易于培养、可移植性和允许转导基因稳定长期表达的潜力。 具体目标是：l。将G-CSF慢病毒接种于灰色牧羊犬、正常犬和大鼠，以确定载体介导的细胞因子表达的持续时间和病毒再接种的可行性。我们将确定病毒的组织分布。2.研究使用生物隔离装置向大鼠和犬输送持续治疗水平的G-CSF。我们相信这项研究将证明基因转移可用于周期性中性粒细胞减少症的长期治疗，并将应用于治疗对分泌的激素和凝血因子有反应的其他血小板减少症和遗传性疾病。该提案的总体目标是在大型动物模型中生成可应用于患者治疗的临床数据。

DESCRIPTION (provided by applicant): Cyclic neutropenia is a rare disease that occurs both in man and grey collie dogs. The recurrent severe neutropenia leads to bacterial infections and shortened life expectancy. Long-term daily administration of recombinant G-CSF eliminates the severe recurrent neutropenia and provides therapy for dogs and patients. This research will study the treatment of grey collie dogs with cyclic hematopoiesis by delivery of G-CSF using two different approaches. In one aim we will study in vivo lentivirus-mediated delivery of canine G-CSF. In another aim G-CSF will be delivered by cell implants employing transduced allogeneic cells in bioisolator devices that eliminate the need for immunosuppression. We have previously shown that long-term administration of recombinant canine G-CSF abolishes the recurrent hematopoietic cycling in affected dogs and we have data showing increased neutrophil production in an affected dog administered lentivirus encoding canine G-CSF. We will administer G-CSF encoding lentivirus to muscle of grey collie and normal dogs and rats. We will investigate implantation of transduced vascular smooth muscle cells in bio-isolator devices to provide safe long-term expression of G-CSF in rats, normal dogs and grey collies. These target cells were chosen for ease of culture, transplantability and potential to allow stable long-term expression of transduced genes. The Specific Aims are: l. To administer G-CSF lentivirus to grey collie, normal dogs and rats to determine the duration of vector-mediated cytokine expression and the feasibility of virus re-administration. We will determine the tissue distribution of virus. 2. To investigate the use of bioisolator devices to deliver sustained therapeutic levels of G-CSF to rats and dogs. We believe this research will demonstrate that gene transfer can be used for long-term treatment of cyclic neutropenia, and will have an application in the treatment of other neutropenias and genetic disorders responding to secreted hormones and clotting factors. The overall goal of this proposal is to generate clinical data in a large animal model that can be applied to the treatment of patients.