FIG. 4.

Establishment of permanent producer cell lines of HTLV-2 mutants. (A) Viral protein expression in permanent transfectants. Three independently isolated 729 stable producer cell clones for the Rex H2A157D and H2S158Term mutants were isolated as described in Materials and Methods. Cells (5 × 10⁶) were plated in each well of six-well plates, and p19 Gag production was measured in 48-h culture supernatants by ELISA. The 729wtHTLV-2 cell line was used as the positive control. (B) Viral protein expression, including Rex and Tax, and β-actin as a loading control were detected by Western blot analysis for selective stable producer cell lines (black bars in panel A) to be used in coculture analysis. wt p24 and p26 are indicated, and the arrow identifies the truncated Rex. α, anti.