Adenoviral-mediated gene transfer in lymphocytes

Although adenovirus can infect a wide range of cell types, lymphocytes are not generally susceptible to adenovirus infection, in part because of the absence of the expression of the cellular receptor for the adenoviral fiber protein. The cellular receptor for adenovirus and coxsackievirus (CAR) recently was cloned and shown to mediate adenoviral entry by interaction with the viral fiber protein. We show that the ectopic expression of CAR in various lymphocyte cell lines, which are almost completely resistant to adenovirus infection, is sufficient to facilitate the efficient transduction of these cells by recombinant adenoviruses. Furthermore, this property of CAR does not require its cytoplasmic domain, consistent with the idea that CAR primarily serves as a high affinity binding site for the adenoviral fiber protein, and that viral entry is mediated by interaction of the viral penton base proteins with cellular integrins. As a demonstration of their functional utility, we used CAR-expressing lymphocytes transduced with an adenovirus expressing Fas ligand to efficiently kill Fas receptor-expressing tumor cells. The ability to efficiently manipulate gene expression in lymphocyte cells by using adenovirus vectors should facilitate the functional characterization of pathways affecting lymphocyte physiology.

尽管腺病毒可感染多种细胞类型，但淋巴细胞通常不易被腺病毒感染，部分原因是其缺乏腺病毒纤突蛋白的细胞受体表达。近期，腺病毒与柯萨奇病毒的细胞受体（coxsackievirus and adenovirus receptor, CAR）被成功克隆，并被证实可通过与病毒纤突蛋白结合介导腺病毒的侵入。本研究证实，在几乎完全抵抗腺病毒感染的多种淋巴细胞系中异位表达CAR，即可有效促进重组腺病毒对这些细胞的转导。此外，CAR的这一功能并不依赖其胞质结构域，这与以下观点一致：CAR主要作为腺病毒纤突蛋白的高亲和力结合位点，而病毒的侵入则由病毒五邻体基底蛋白与细胞整合素的相互作用所介导。为验证其功能实用性，我们利用表达CAR的淋巴细胞，结合携带Fas配体的腺病毒进行转导，实现了对表达Fas受体的肿瘤细胞的高效杀伤。通过腺病毒载体实现淋巴细胞中基因表达的高效调控，将有助于推动影响淋巴细胞生理过程的信号通路的功能鉴定。