Abstract:

Wang Fei *, Guo Zongke, Zhang Hongye, Pan Yongzheng, Dong Zhengbang, Chen Mei, Shan Ying, Yan Qiao, Yu Weiping. *Department of Dermatology, Zhongda Hospital, Southeast University, Nanjing 210009, China Corresponding author: Wang Fei, Email: ffwangfei@163.com 【Abstract】 Objective To establish a model for preparation of tissue-engineered skin grafts with hTERT cells carrying human papillomavirus type 6 （HPV 6） genome in vitro, so as to lay a foundation for studying HPV life cycle. Methods The full-length linear HPV6 genome and plasmid pEGFP-▲EGFP were electrophoretically cotransferred into hTERT cells. After selection using G418 resistance, Southern blotting was performed to determine the viral load of HPV6 in transfected cells. 3T3 J2 trophoblastic cells, type I rat-tail collagen and hTERT cells containing the full-length HPV6 genes （HPV6.hTERT cells） were mixed and cocultured on metal meshes to form skin graft-like structures. Hematoxylin and eosin （HE） staining was performed to observe the structure of formed skin grafts, an immunohistochemical assay to measure the expression of HPV6 L1 protein, and electron microscopy to observe virus particles in the skin grafts. Results The linear HPV6 gene was successfully transferred into hTERT cells, and Southern blotting showed the presence of HPV6 DNA in the transferred hTERT cells. The HPV6.hTERT cells, which were cocultured with 3T3 J2 trophoblastic cells and type I rat-tail collagen, proliferated and differentiated over time, and gradually formed skin grafts giving the appearance of verrucous hyperplasia. HE staining showed that the cocultured HPV6.hTERT cells could form typical stratified structure of skin after 7 days of cultivation, and histopathologic features of HPV infection, including obvious papillomatous hyperplasia, presence of vesicular cells, hyperkeratosis and parakeratosis, could be observed after 21 days. The immunohistochemical assay showed the expression of HPV6 L1 protein in the upper portion of skin grafts, and electron microscopy revealed the presence of HPV6 virus particles in skin grafts. Conclusions The established model for preparation of tissue-engineered skin grafts using HPV 6 genome-carrying cells provides a basis for biological studies of HPV, but its application is limited to some degree.