Differential role of α_vβ₃ and α_vβ₅ integrins in internalization and transduction efficacies of wild type and RGD4C fiber-modified ad

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• 作者：Dragomira Majhen ; Josip Nemet ; Jennifer Richardson ; Jelka Gabrilovac ; Martina Hajsig ; Maja Osmak ; Marc Eloit ; Andreja Ambriović ; -Ristov
• 关键词：Adenovirus ; α ; _vβ ; ₃ integrin ; α ; _vβ ; ₅ integrin ; Transduction ; Internalization ; Fiber ; RGD4C
• 刊名：Virus Research
• 出版年：2009
• 出版时间：January 2009
• 年：2009
• 卷：139
• 期：1
• 页码：64-73
• 全文大小：716 K

文摘

In order to analyze the role of α_vβ₃ and α_vβ₅ integrins in gene transfer by adenovirus-based vectors, an RGD4C motif was inserted into the HI-loop of wild type or shortened fiber protein of human adenovirus of serotype 5, thereby creating Ad5RGD4C and Ad5Δ639RGD4C vectors, respectively. Infection by the latter is independent of the Coxsackie B adenovirus receptor. Internalization and transduction of these vectors and were investigated in several stably transfected cell clones derived from a human laryngeal carcinoma cell line (HEp2) expressing different ratios of α_vβ₅ and α_vβ₃ integrins. We show that α_vβ₃ is more successful than α_vβ₅ in: (i) mediating adenovirus internalization and transduction when the RGD motif is present only in the penton base and (ii) mediating internalization and transduction by RGD4C-fiber modified adenoviruses. The highest amount of internalized virus was found in the cell clone in which α_vβ₃ integrin predominated over α_vβ₅ integrin (as judged by the % of cells expressing α_vβ₃ and α_vβ₅ integrins). However the level of transgene expression in this cell line was even lower than that in parental HEp2 cells which do not express α_vβ₃ integrin. This discrepancy between internalization and transgene expression (transduction) is likely due to the crucial role of α_vβ₅ in membrane permeabilization, indicating that α_vβ₅ integrin is a limiting factor for Ad5-mediated gene transfer. We conclude that α_vβ₃ integrin is an efficient adenovirus internalization receptor, but cannot functionally replace α_vβ₅ in endosomal release.