By contrast , memory cells , either in vitro activated helper T cells reverting to a resting state , or CD4+ T ( memory ) clones , or CD4+CD45RO+ T cells isolated ex vivo , no longer have a silencer .
by contrast , memory cells , either in vitro activated helper t cells reverting to a resting state , or cd4+ t ( memory ) clones , or cd4+cd45ro+ t cells isolated ex vivo , no longer have a silencer .
O O O O 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 B-cell_line I-cell_line I-cell_line I-cell_line I-cell_line I-cell_line O O B-cell_line I-cell_line I-cell_line O O O O O O O O B-DNA_family_or_group O