Proteome of monocytes primed with lipopolysaccharide: Analysis of the abundant proteins

We performed a proteomic analysis of monocytes primed by lipopolysaccharide (LPS) in vitro, using two-dimensional gels stained with Coomassie blue. We found 16 proteins of similar to500 detected that either increased or decreased in abundance as a result of priming by LPS (14 with P < 0.05). The proteins were identified by comparing the masses of their tryptic pepticles with those of all known proteins, using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and the SWISS-PROT database. Identities were confirmed by matching the sequence of several tryptic peptides, using liquid chromatography electrospray-ionization quadrupole ion trap mass spectrometry. There were increases in the protective enzymes superoxide dismutase and catalase, in four calgranulins, in the cytokine pre-B cell enhancing factor, and in annexin 2, macrophage capping protein, transketolase, pyruvate kinase, and serine/ threonine protein kinase 10. Proteins that decreased in abundance were integrin alpha-IIB, protein disulfide isomerase, and. platelet-activating factor acetylhydrolase. Many of these altered proteins have interesting functions in inflammation.