Healthy donor CD4+ T-cells were treated daily with 100 μM Meth, and miR-146a expression was assessed. We observed that Meth significantly up-regulated miR-146a on day 3 of treatment (Figure 2A). Likewise, we assessed IL-1β mRNA levels in untreated and Meth treated cells. Unlike extracellular IL-1β, which increased after 1 day of Meth treatment, IL-1β mRNA showed increased expression only on day 3 (Figure 2A). Notably, IL-1β release and mRNA expression are controlled by distinct mechanisms (45). In addition, CD4+ T-cells constitutively express pro-IL-1β in their cytoplasm (46). As such, our results indicate that Meth first enhances release of mature IL-1β, followed by increased IL-1β gene transcription and miR-146a expression.