Specific inhibition of a human papillomavirus E2 trans-activator by intracellular delivery of its repressor.
Papillomaviruses are the causative agents of benign and malignant epithelial tumors of the skin and mucosa. They encode a DNA-binding protein, E2, that regulates viral transcription and replication, making it an important therapeutic target. By deleting the amino-terminal trans-activation domain of human papillomavirus type 16 (HPV-16) E2 while retaining its carboxy-terminal DNA binding and dimerization domain, an E2 repressor (E2R) that efficiently inhibits transcriptional activation by full-length HPV E2 was generated. To deliver this repressor protein into animal cells, we have utilized the human immunodeficiency virus type 1 (HIV-1) Tat protein which itself is taken up efficiently into intact cells. Chimeras of E2R and the cellular uptake domain of Tat specifically inhibited E2-dependent reporter gene expression in COS-7 cells. Treatment of cervical intraepithelial neoplasia cells having episomally replicating HPV-31 DNA with this Tat-E2R protein led to a dose-dependent loss of HPV DNA copies and inhibition of cell growth. Tat-mediated delivery can be a valuable tool for assessing protein function and may allow the development of novel therapeutic proteins having intracellular targets.
Pepinsky
R B
RB
Biogen, Inc., Cambridge, MA 02142.
Androphy
E J
EJ
Corina
K
K
Brown
R
R
Barsoum
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D015696:Gene Products, tat / Q000378:metabolism; D008969:Molecular Sequence Data; D009856:Oncogene Proteins, Viral / Q000378:metabolism*; D027383:Papillomaviridae / Q000235:genetics*; D012097:Repressor Proteins / Q000378:metabolism*; D015534:Trans-Activators / Q000037:antagonists & inhibitors*; D014407:Tumor Cells, Cultured; D002578:Uterine Cervical Dysplasia
D004279:DNA, Viral; D004268:DNA-Binding Proteins; C054855:E2 protein, Human papillomavirus type 16; D015696:Gene Products, tat; D009856:Oncogene Proteins, Viral; D012097:Repressor Proteins; D015534:Trans-Activators