FIG. 5.

Effects of pretreatment with gp120 protein on LPS-induced up-regulation of MOR mRNA expression in TPA-HL-60 cells. TPA-HL-60 cells were pretreated with either vehicle medium or 1 nM recombinant gp120 protein for 24 h and then treated for an additional 12 h with control vehicle (culture medium) or different concentrations of LPS (10 ng/ml or 100 ng/ml). The effects of gp120 pretreatment on LPS-induced up-regulation of MOR expression were then examined by real-time RT-PCR. n = 3; *, P < 0.05 compared to control vehicle; ^, P < 0.05 compared to treatment with vehicle followed by LPS at 10 ng/ml and 100 ng/ml, respectively.