tokens: The observation that human herpesvirus 6 ( HHV-6 ) can induce CD4 gene transcription and expression in CD4 ( - ) cells was reported several years ago ( P . Lusso , A . De Maria , M . Malnati , F . Lori , S . E . DeRocco , M . Baseler , and R . C . Gallo , Nature 349 : 533-535 , 1991 ) and subsequently confirmed ( P . Lusso , M . S . Malnati , A . Garzino-Demo , R . W . Crowley , E . O . Long , and R . C . Gallo , Nature 362 : 458-462 , 1993 ; G . Furlini , M . Vignoli , E . Ramazzotti , M . C . Re , G . Visani , and M . LaPlaca , Blood 87 : 4737-4745 , 1996 ) .
folded_tokens: the observation that human herpesvirus 6 ( hhv-6 ) can induce cd4 gene transcription and expression in cd4 ( - ) cells was reported several years ago ( p . lusso , a . de maria , m . malnati , f . lori , s . e . derocco , m . baseler , and r . c . gallo , nature 349 : 533-535 , 1991 ) and subsequently confirmed ( p . lusso , m . s . malnati , a . garzino-demo , r . w . crowley , e . o . long , and r . c . gallo , nature 362 : 458-462 , 1993 ; g . furlini , m . vignoli , e . ramazzotti , m . c . re , g . visani , and m . laplaca , blood 87 : 4737-4745 , 1996 ) .
labels: O O O B-virus I-virus I-virus O B-virus O O O B-DNA_domain_or_region I-DNA_domain_or_region O O O O B-cell_line I-cell_line I-cell_line I-cell_line I-cell_line O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O