Fig. 5.

IL-7 augmented CD3/CD28/IFNα-induced T-cell proliferation is suppressed by THC. PBMCs from healthy and HIV⁺ donors were isolated through Ficoll Paque density gradient centrifugation. Cells were stained with violet CellTrace dye and then treated with either vehicle (0.03% EtOH) or various concentrations of THC (1, 5, or 10 µM) for 30 minutes. After treatment, cells were stimulated with IFNα (100 U/ml) and anti-CD3 and anti-CD28 antibodies (2.5 μg/ml each) for 48 hours, treated with IL-7 (10 ng/ml) or vehicle (endotoxin-free H₂O), and incubated for another 48 hours before harvesting. T-cell proliferation is represented as the DI, as determined by the FlowJo proliferation tool. (A) Representative experiment of IL-7–mediated augmentation of T-cell proliferation in CD3/CD28/IFNα-stimulated T cells and THC (10 µM)-mediated suppression in a healthy donor. The effects of treatment with IFNα and IL-7 on anti-CD3/CD28-mediated T-cell proliferation in CD4⁺ (B) and CD8⁺ (C) T cells from healthy and HIV⁺ donors. The effect of IL-7 stimulation on total CD3⁺ T-cell composition and between memory (CD45RO⁺) and nonmemory (CD45RO⁻) cells in CD4⁺ (D) and CD8⁺ (E) T cells. The effects of THC on the IL-7–induced augmentation of CD3/CD28/IFNα-induced proliferation of T cells from healthy and HIV⁺ donors in total (F), memory (G), and nonmemory (H) CD4⁺ cells; and total (I), memory (J), and nonmemory (K) CD8⁺ cells. Pound signs indicate statistically significant differences in the proliferation of IL-7 treated T cells compared to T cells without IL-7 treatment (#P ≤ 0.05). Asterisks indicate statistically significant differences of the treatment with the HIV status–matched VC (0 THC or D0) (*P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001). Daggers indicate statistically significant differences of treatment-matched groups between healthy and HIV⁺ T cells (†P ≤ 0.05; ††P ≤ 0.01) (two-way analysis of variance with Bonferroni multiple-comparisons post-test). D0, day 0; SSC-A, side scatter area.