Merten Christoph A, Engelstaedter Martin, Buchholz Christian J, Cichutek Klaus
Department of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany
Virology. 2003 Jan 5;305(1):106-14. doi: 10.1006/viro.2002.1778.
Targeted gene transfer into human cells has previously been achieved with spleen necrosis virus (SNV)-derived vector particles harboring envelope (Env) proteins which carry single chain Fv (scFv) domains derived from antibodies. Such cell targeting vectors have been found to directly transduce human cells expressing the cell surface molecules recognized by the respective scFv. In an attempt to achieve targeted gene transfer into epidermal growth factor receptor (EGFR)-positive human cells, SNV vector particles carrying a surface (SU) envelope protein N-terminally modified with the EGF domain and the wildtype transmembrane protein were generated. However, direct transduction of EGFR-positive cells was not detected. Canine D17 cells, which can be infected by wildtype SNV, were also not transduced. Infectivity of D17 cells was restored by removal of the EGF modification via cleavage of a factor Xa site located between the EGF domain and the SU protein or by blocking the EGFRs on the cell surface by EGF treatment. The properties of SNV-EGF vector particles as described here are similar to those of murine leukemia virus-derived vector particles harboring envelope proteins modified with a growth factor-derived domain. It seems therefore that, although scFv-modified SNV allows direct cell targeting, EGF-modified SNV allows only indirect cell targeting.
以前，通过携带包膜（Env）蛋白的脾坏死病毒（SNV）衍生载体颗粒实现了向人类细胞的靶向基因转移，这些包膜蛋白带有源自抗体的单链Fv（scFv）结构域。已发现此类细胞靶向载体可直接转导表达被相应scFv识别的细胞表面分子的人类细胞。为了实现向表皮生长因子受体（EGFR）阳性人类细胞的靶向基因转移，构建了携带在N端用EGF结构域修饰的表面（SU）包膜蛋白和野生型跨膜蛋白的SNV载体颗粒。然而，未检测到EGFR阳性细胞的直接转导。可被野生型SNV感染的犬D17细胞也未被转导。通过切割位于EGF结构域和SU蛋白之间的因子Xa位点去除EGF修饰，或通过用EGF处理阻断细胞表面的EGFR，可恢复D17细胞的感染性。本文所述的SNV-EGF载体颗粒的特性与携带用生长因子衍生结构域修饰的包膜蛋白的鼠白血病病毒衍生载体颗粒的特性相似。因此，似乎虽然scFv修饰的SNV允许直接细胞靶向，但EGF修饰的SNV仅允许间接细胞靶向。
