Down regulation of CD14 expression through pretreatment with glucocorticoids

Glucocorticoids such as cortisol are potent immunosuppressive agents that act on many cells of the body, including macrophages. Macrophages express CD14 in response to lipopolysaccharides (LPS) extracted from bacterial coats. The objectives of this study were: (1) to determine if pretreatment of macrophages with cortisol for 30 minutes prior to challenging the cells with endotoxin results in increased cell loss, cell damage (MDA), and suppression of CD14 receptors; and (2) to determine if CD14 receptor expression is able to recover with time. An experimental design incorporating RAW 264.7 cells (RAW) was used in order to evaluate our objectives. The cells were plated on 24 well plates and subsequently divided into four groups. The first group was untreated and served as the control. Group two was treated with LPS, group three with 10 uL of cortisol and a combination of LPS and cortisol was used in the treatment of the fourth group. The cells were recovered at 24, 48, and 72 hours. Results showed that there was a significant decrease in the proliferation rate in RAW cells exposed to cortisol and LPS either alone of in combination when compared to the untreated cells. Cell damage was also increased in treated cells. LPS caused receptor expression at all time points. CD14 expression was down regulated at 48 hours in cells pretreated with cortisol, however, this suppression was no longer evident at 72 hours.