Inhibition of PA28γ expression increases HTLV-1 replication and virus production. (A-C) ELISA p19 assay was performed every 24 hours for 96 hours after transfection of 293FT and FT-27 cells with distinct HTLV-1 molecular clones (pBST, ACH, and X1MT). Western blots analyses confirmed increased p24 in FT-27 cells lacking PA28γ expression. (D) Replication of HTLV-1 molecular clone pAB and its counterpart pABΔp30 was analyzed in FT and FT-27 cells transfected with respective molecular clones and HTLV-1-LTR-luciferase.