Effects of Meth on dopamine receptors and <t>sigma-1</t> receptor in CD4 + T-cells. ( A ) CD4 + T-cells were untreated or treated with 100 µM Meth for different time points (5 mins-24 hours), lysed and the protein extracts were analyzed for the expression of various dopamine receptors and sigma-1 receptor. <t>GAPDH</t> used as a loading control. Full-length blots are presented in Supplementary Fig. S3 . ( B ) Fold change in the pixel density of sigma-1 receptor expression in ( A ). All values normalized to untreated sample. (*p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001). ( C ) CD4 + T-cells were untreated or treated with 10 µM sigma-1 receptor inhibitor (σ1 R inh.) for 1 hour, then treated with or without 100 µM Meth for 1 hour, followed by lysis and analysis of protein extracts for the indicated activated signaling molecules by Western blotting. GAPDH used as a loading control. Full-length blots are presented in Supplementary Fig. S3 . ( D ) HIV-1 p24 titer on day 3 after HIV-1 infection in unstimulated and stimulated CD4 + T-cells pretreated with or without sigma-1 receptor inhibitor (σ1 R inh.) and treated in the presence or absence of Meth. Data represent the mean ± SD of 3 independent experiments (**p ≤ 0.01, ***p ≤ 0.001).