Suk Jung Soo, Suh Junghae, Lai Samuel K, Hanes Justin
Department of Chemical & Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA.
Exp Biol Med (Maywood). 2007 Mar;232(3):461-9.
Real-time confocal particle tracking (CPT) was used to compare the transport and trafficking of polyethylenimine (PEI)/DNA nanocomplexes to that of efficient adenoviruses in live primary neurons. Surprisingly, the quantitative intracellular transport properties of PEI/DNA nonviral gene vectors are similar to that of adenoviral vectors. For example, the values of individual particle/virus transport rates and the distributions of particle/virus transport modes (i.e., the percentage undergoing active, diffusive, or subdiffusive transport) largely overlapped. In addition, both PEI/DNA vectors and adenoviruses rapidly accumulated near the cell nucleus in primary neurons despite our finding that PEI/DNA move slower in neurites than in the cell body, whereas adenoviruses move with equal rates in either location. The intracellular trafficking pathways of PEI/DNA and adenoviruses, however, were substantially different. The majority of PEI/DNA trafficked through the endolysosomal pathway so as to end up in late endosomes/lysosomes (LE/Lys), whereas adenoviruses efficiently escaped endosomes. This result suggests that the sequestration of nonviral gene vectors within acidic vesicles may be a critical barrier to gene delivery to primary neurons in the central nervous system (CNS).
实时共聚焦粒子追踪（CPT）被用于比较聚乙烯亚胺（PEI）/DNA纳米复合物与高效腺病毒在原代活神经元中的转运和运输情况。令人惊讶的是，PEI/DNA非病毒基因载体的定量细胞内转运特性与腺病毒载体相似。例如，单个粒子/病毒转运速率的值以及粒子/病毒转运模式的分布（即经历主动、扩散或亚扩散转运的百分比）在很大程度上重叠。此外，尽管我们发现PEI/DNA在神经突中的移动速度比在细胞体中慢，而腺病毒在这两个位置的移动速度相同，但PEI/DNA载体和腺病毒在原代神经元中都迅速在细胞核附近积累。然而，PEI/DNA和腺病毒的细胞内运输途径却有很大不同。大多数PEI/DNA通过内溶酶体途径运输，最终进入晚期内体/溶酶体（LE/Lys），而腺病毒能有效逃离内体。这一结果表明，酸性囊泡中对非病毒基因载体的隔离可能是向中枢神经系统（CNS）原代神经元进行基因递送的关键障碍。
