Vaping is "unlikely to be risk free," finds evidence review.

Abstract

We previously reported that cannabidiol (CBD), one of the <i>Cannabis sativa</i>-derived cannabinoids, induced functional CD4⁺CD25⁺FOXP3⁺ Tregs in response to low level stimulation of PMA/Io. CBD increased CD25⁺FOXP3⁺ cells in CD4⁺, CD4⁺CD25⁺, and CD4⁺CD25⁻ T cells, as well as in CD4⁺ T cells derived from FOXP3-GFP mice. T cell stimulation conditions were suboptimal PMA/Io (4 nM/0.05 μM, S/o) and ultrasuboptimal PMA/Io (1 nM/0.0125 μM, Us/o). We also observed that CBD + Us/o increased IL-2, IL-10 and TGF-β1 immunomodulatory cytokines. Here, we measured the effect of CBD + Us/o or S/o on CD4⁺ cells. Splenocytes were treated with CBD (1–10 μM) for 30 min plus S/o or Us/o activation and cultured for 1 day or 5 days. Immunofluorescence staining showed that CBD + Us/o treatment increased the percentage of CD4⁺ cells while CBD + S/o treatment decreased the percentage of CD4⁺cells. CD4⁺CD25⁺ expression by Us/o or S/o activation alone was also measured. CD25 expression in response to Us/o activation was lower than that by S/o activation in CD4⁺ cells. This study will provide important information on the effect of CBD on CD4 cells under differential immunological activation state by PMA/Io.