Gene product delivery by engineered somatic cells

描述（由申请人提供）：此R21申请是对计划公告PA-03-058的响应。本计划公告的既定目标是邀请申请探索性或开发性生物工程研究（EBRG）。生物工程研究的一个例子是：药物、基因或细胞治疗传递系统的研究。本提案针对这一例子。理想的基因产物递送系统应具有四个主要特征。(1)它应该以高效率递送;（2）它应该表现出延长的基因表达;（3）它应该表现出无毒性;以及（4）它应该适用于整个患者群体而无需任何定制。在小鼠模型中工作，我们建议开发一种满足所有这些要求的基因递送系统。拟议的治疗包括将MHC不匹配的转基因表达基质细胞系注射到胸腺中。我们将确定受体小鼠是否对注射的细胞系耐受，尽管由于胸腺微环境的独特性质（上文第4点）导致MHC错配。我们将检查受体以确认注射的细胞保留在注射部位（第1点），我们将监测基因产物的长期表达（第2点），同时寻找与胸腺中存在递送细胞相关的任何可能的病理学（第3点）。胸腺内注射转基因表达细胞后的长期基因产物递送可以彻底改变许多单基因缺陷疾病的治疗。

DESCRIPTION (provided by applicant): This R21 application is in response to the program announcement PA-03-058. The stated objective of this program announcement is to invite applications in exploratory or developmental bioengineering research (EBRG). One listed example of bioengineering research is: Research on drug, gene, or cellular therapeutic delivery systems. This proposal addresses this example. The ideal gene product delivery system would have four main characteristics. (1) It should be delivered with high efficiency; (2) it should exhibit prolonged gene expression (3) it should be show no toxicity; and (4) it should be applicable to the entire patient population without any need for customization. Working in a murine model, we propose to develop a gene delivery system that meets all these requirements. The proposed therapy involves the injection of an MHC-mismatched, transgene-expressing stromal cell line into the thymus. We will establish whether the recipient mice are tolerant to the injected cell line, despite the MHC mismatch, due to the unique nature of the thymic microenvironment (point 4 above). We will examine the recipients to confirm that the injected cells remained at the site of injection (point 1), and we will monitor long-term expression of the gene product (point 2) while looking for any possible pathology related to presence of the delivery cells in the thymus (point 3). Long term gene product delivery following intrathymic injection of transgene-expressing cells could revolutionize treatment of a number of single gene defect disorders.