Inflammation is a physiological process involved in many diseases. Monitoring 
proteins involved in regulatory effects may help to improve our understanding of 
inflammation. We have analyzed proteome alterations induced in peripheral blood 
mononuclear cells (PBMCs) upon inflammatory activation in great detail using 
high-resolution mass spectrometry. Moreover, the activated cells were treated 
with dexamethasone to investigate their response to this antiphlogistic drug. 
From a total of 6886 identified proteins, 469 proteins were significantly 
regulated upon inflammatory activation. Data are available via ProteomeXchange 
with identifiers PXD001415-23. Most of these proteins were counter-regulated by 
dexamethasone, with some exceptions concerning members of the interferon-induced 
protein family. To confirm some of these results, we performed targeted MRM 
analyses of selected peptides. The inflammation-induced upregulation of proteins 
such as IL-1β, IL-6, CXCL2, and GROα was confirmed, however, with strong 
quantitative interindividual differences. Furthermore, the inability of 
dexamethasone to downregulate inflammation-induced proteins such as PTX3 and 
TSG6 was clearly demonstrated. In conclusion, the relation of cell function as 
well as drug-induced modulation thereof was successfully mapped to proteomes, 
suggesting targeted analysis as a novel and powerful drug evaluation method. 
Although most consequences of dexamethasone were found to be compatible with the 
expected mode of action, some unexpected but significant observations may be 
related to adverse effects.