FIG 4.

Effects of GRAIL (gene related to anergy in lymphocytes) and ICER (inducible cAMP early repressor) expression on activation-induced HIV-1 reactivation. High levels of GRAIL and ICER are hallmarks of T cell anergy. Latently HIV-1 infected CA5 T cells were retrovirally transduced to express increased levels of ICER or GRAIL. Two days postransduction, the parental cells and the retrovirally transduced cell populations were stimulated with PMA (10 ng/ml), and the level of HIV-1 reactivation was measured by flow cytometry using GFP as a surrogate marker of HIV-1 expression. The cells were not selected with puromycin. For many transgenic cell lines, we observe relatively fast adaptation to a new phenotype or reversion to the parental phenotype within days, which no longer represents the actual initial transgenic effect. The estimated transduction efficacy was 40 to 60%.