RECOMBINANT ADENO ASSOCIATED VIRUS

基于腺相关病毒（AAV）的哺乳动物转导载体可 保留了野生型病毒的特性。 野生型AAV 在允许细胞中复制到高滴度，具有物理稳定性 颗粒，整合到细胞基因组中，是非细胞遗传性的， 被认为具有广泛的宿主范围，并且似乎不受限制 在组织向性上。 此外，细胞分裂也不被考虑 对病毒感染至关重要。 重组AAV（rAAV）的生产 需要反式表达AAV rep和cap基因， AAV反向末端重复序列（ITR）的顺式。 rAAV的产生 可能受到病毒结构基因拷贝数的限制 转染到细胞中，而在野生型AAV感染中， 随着病毒基因组的复制，数量呈几何级数增长。 到 为了克服这一障碍，我们利用了SV 40复制起点 在一个含有质粒的芯片上 这种质粒在细胞中扩增 表达SV 40 T-Ag。 结合高效率 电穿孔，重组病毒颗粒的产量增加 60-折叠在非复制型辅助质粒上。 CsCl等密度后 梯度离心，鉴定含有rAAV的组分 通过瞬时感染试验和DNA斑点杂交。 的 rAAV颗粒的密度为1.40 - 1.42 g/ml。 杂交 梯度洗脱证明重组AAV基本上是 没有污染的腺病毒。 此外，粒度为 通过条带的电子显微照片确定约20-25 nm 材料 浮力密度和物理外观都相似 与野生型颗粒的测定值相比。 这种新的rAAV包装系统已被用于生产rAAV颗粒 它含有T细胞共刺激蛋白B7-2的基因。 人非粘附淋巴样细胞系LP-1的转导 用编码B7-2的AAV转导导致78%的细胞表达 B7-2 B7-2在人淋巴样细胞系RPMI 8226中的表达， 也大幅增加。

Mammalian transduction vectors based on adeno-associated virus (AAV) may retain properties attributed to the wild-type virus. Wild-type AAV replicates to high titer in permissive cells, has a physically stable particle, integrates into the cellular genome, is non-cytogenic, and is considered to have broad host range and does not appear to be restricted in tissue tropism. In addition, cell division is not considered essential for viral infection. Production of recombinant AAV (rAAV) requires expression of AAV rep and cap genes in trans and the presence of the AAV inverted terminal repeats (ITR) in cis. Generation of rAAV may be limited by the copy number of the viral structural genes transfected into cells, whereas in a wild-type AAV infection, the copy number increases geometrically as the viral genome is replicated. To overcome this obstruction, we have utilized an SV40 origin of replication on a rep and cap containing plasmid. This plasmid is amplified in cells expressiong SV40 T-Ag. In conjunction with high efficiency electroporation, the yield of recombinant viral particles was increased 60-fold over a non-replicating helper plasmid. Following CsCl isopycnic gradient centrifugation, the fractions containing rAAV were identified by transient infection assays and DNA dot blot hybridization. The density of the rAAV particles was 1.40 - 1.42 g/ml. Hybridization of the gradient fractions demonstrated that the recombinant AAV was essentially free of contaminating adenovirus. Furthermore the particle size was of approximately 20-25 nm was determined by electromicrographs of the banded material. Both the buoyant density and physical appearence are similar to those determined for wild type particles. This novel rAAV packaging system has been used to produce rAAV particles which contains the gene for the T-cell co-stimulatory protein, B7-2. Transduction of the human, non-adherent lymphoid cell line, LP-1 transduced with B7-2 encoding AAV resulted in 78% of cells expressing B7-2. Expression of B7-2 in the human lymphoid cell line RPMI 8226 was also substantially increased.