Human papillomavirus type 31b @entity281 of XXXX keratinocytes and the onset of early transcription.

@entity1 @entity281 @entity5
@entity1 papillomaviruses (HPVs) cause a number of @entity1 @entity5 and @entity5 , including @entity5 . Epithelial differentiation is required for the complete HPV life cycle and can be achieved using the organotypic (raft) culture system. The CIN-612 9E cell line maintains episomal copies of HPV type 31b (HPV31b), an @entity5 . When grown in the raft system, CIN-612 9E cells form a differentiated epithelium such that infectious virions can be synthesized. Many aspects of the later stages of the HPV31b life cycle have been investigated in CIN-612 9E raft tissues. We used a biologically contained homogenization system for efficient virion extraction from raft epithelial tissues. Purified HPV31b virions were used to infect low-passage-number @entity1 foreskin keratinocytes and a variety of epithelial cell lines. Newly synthesized, spliced HPV31b transcripts were detected by reverse transcription and PCR (RT-PCR) following @entity281 . @entity281 was most efficient and reproducible in HaCaT cells. The onset of viral transcription following @entity281 was also investigated using RT-PCR techniques. Spliced E1(*)I,E2 RNAs were present as early as 4 h postinfection (p.i.), whereas the other major viral transcripts were detected by 8 to 10 h p.i. Furthermore, we characterized the structures and temporal expression of seven novel spliced early transcripts expressed following @entity281 .
