Lo W D, Qu G, Sferra T J, Clark R, Chen R, Johnson P R
Department of Pediatrics, The Ohio State University, Columbus 43205, USA.
Hum Gene Ther. 1999 Jan 20;10(2):201-13. doi: 10.1089/10430349950018995.
Adeno-associated virus (AAV) is a promising vector for central nervous system (CNS) gene transfer, but a number of issues must be addressed if AAV is to be used for widespread delivery throughout the CNS. Our aim was to test the effect of dose, route of delivery, and hydroxyurea treatment on brain expression of beta-galactosidase activity after cerebral inoculation with an rAAV-lacZ vector (rAAV-beta-gal). We also wished to test whether an immune response appeared against the vector and the transgene product. We found in BALB/c mice that beta-Gal expression increased during the first 2 months after inoculation, then decreased slightly by 4 months, and continued out to 6, 12, and 15 months in single animals. Cerebral injection produced localized beta-Gal expression that did not diffuse to other regions despite a fivefold increase in injection volume. Intraventricular injection resulted in negligible transduction. Antibodies to AAV capsid protein and beta-Gal appeared at low levels at 2 and 4 months, but correlated poorly with beta-Gal expression and did not prevent readministration of rAAV-beta-gal. Hydroxyurea treatment did not result in increased transduction in vivo. We conclude that our study confirms rAAV vectors as having considerable potential for CNS gene transfer; however, several important problems must be addressed if this vector system is to be used for long-term transduction of the entire brain. Sustained, regulatable expression will be needed if rAAV is to be used in the treatment of chronic CNS disease. The difficulty in delivering AAV to diverse regions of the brain is an important problem that must be overcome if these vectors are to be used for anything beyond localized transduction.
腺相关病毒（AAV）是用于中枢神经系统（CNS）基因转移的一种很有前景的载体，但如果要将AAV用于整个CNS的广泛递送，还必须解决一些问题。我们的目的是测试剂量、递送途径和羟基脲处理对用rAAV-lacZ载体（rAAV-β-gal）脑内接种后β-半乳糖苷酶活性在脑内表达的影响。我们还希望测试是否出现针对该载体和转基因产物的免疫反应。我们发现在BALB/c小鼠中，接种后前2个月β-Gal表达增加，然后到4个月时略有下降，在个别动物中持续到6、12和15个月。脑内注射产生局部β-Gal表达，尽管注射体积增加了五倍，但并未扩散到其他区域。脑室内注射导致的转导可忽略不计。针对AAV衣壳蛋白和β-Gal的抗体在2个月和4个月时以低水平出现，但与β-Gal表达相关性很差，并且不阻止再次给予rAAV-β-gal。羟基脲处理在体内并未导致转导增加。我们得出结论，我们的研究证实rAAV载体在CNS基因转移方面具有相当大的潜力；然而，如果要将该载体系统用于整个脑的长期转导，必须解决几个重要问题。如果要将rAAV用于慢性CNS疾病的治疗，将需要持续的、可调节的表达。如果要将这些载体用于局部转导以外的任何用途，将AAV递送至脑的不同区域的困难是一个必须克服的重要问题。
