Objective: We aimed to investigate the differences in interleukin (IL)-10, IL-1β, IL-6, and tumor necrosis factor (TNF)-α expression in lipopolysaccharide (LPS)-stimulated CD14++CD16+ monocytes obtained from asthmatics after dexamethasone or dexamethasone plus rapamycin treatments between clinical steroid responders (R) and non-responders (NR).
Methods: Cytokine expressions in LPS-stimulated CD14++CD16+ p-mammalian target of rapamycin (mTOR) monocytes from R and NR were determined using flow cytometry.
Results: IL-10high CD14++CD16+ p-mTOR population following LPS stimulation increased in the R group although decreased in the NR group with dexamethasone treatment. IL-1βhigh population decreased in the R group although increased in the NR group. Rapamycin treatment after LPS and dexamethasone resulted in a significant increase in the IL-10high population and a significant decrease in the IL-1βhigh population in the NR group.
Conclusion: Dexamethasone treatment resulted in different patterns of change in cytokine expressions in LPS-stimulated CD14++CD16+ p-mTOR monocytes between the R and NR. mTOR inhibition can restore steroid responsiveness involving IL-10 and IL-1β in CD14++CD16+ p-mTOR monocytes.
Keywords: asthma; lipopolysaccharide; monocyte; steroid; target of rapamycin (TOR) serine-threonine kinase.