Figure 11.

Delta-9-tetrahydrocannabinol (Δ⁹-THC) administration inhibited CD8⁺ T cell expansion in peripheral blood during chronic SIV infection. Absolute counts revealed that Delta-9-Tetrahydrocannabinol (Δ⁹-THC) administration did not prevent depletion of CD4⁺ T cells (A) but significantly reduced total CD8⁺ T cell numbers (B) in peripheral blood at 14- and 150-days post-SIV infection. Note that CD8⁺ T cell data from only three VEH/SIV rhesus macaques were available at 180 days post-infection. Open red circles- VEH/SIV, Open blue squares- THC/SIV. Horizontal red and blue lines with P-values denote comparisons between time points within the VEH/SIV and THC/SIV groups, respectively. Left black brackets with an asterisk indicate statistical significance (p = 0.0143) between the VEH/SIV and THC/SIV groups for a given time point. Connecting blue and red lines (A,B) denote mean values of the respective population in the THC/SIV and VEH/SIV groups, respectively. Flow cytometry analysis to determine the effect of Δ⁹-THC on peripheral blood T cell dynamics in SIV-infected rhesus macaques was performed once with three to four individual animals as biological replicates per group. Flow cytometry data were analyzed using linear mixed models with immune-marker outcomes being dependent variables, and treatment status (VEH vs. Δ⁹-THC) and days since the start of treatment (0, 14, 150, 180) being dependent variables with fixed effects. Differences between two post-infection time points were analyzed using the Mann-Whitney U-test employing the Prism v5 software (GraphPad software). A p-value ≤ 0.05 was considered significant.