Figure 4.

Expression of p19 Gag and Tax protein and p28 mRNA in permanent transfectants. (A) Four 729 stable transfectants (clone 1–4) were isolated for HTLV-2Δp28 as described in Materials and Methods. Our well-established 729pH6neo (729.HTLV-2) cell clone was used as the wtHTLV-2 stable producer cell line. p19 Gag was quantified by ELISA from the four independently isolated 729.HTLV-2Δp28 (Clones 1–4), 729.HTLV-2, and the 729 negative control. Each 729.HTLV-2 producer cell line displayed variable p19 production. (B) Clones indicated by asterisks, which have been shown to produce similar quantities of p19 Gag, were further characterized by Western blot for Tax protein expression using rabbit polyclonal antisera raised against Tax-2. β-actin was used as a loading control. Numbers below each lane are the copy number of p28 transcript per 10⁶ copies of GAPDH determined by realtime RT PCR. The results show similar levels of p28 mRNA expression.