Differential Protein Expression Profiles of Human Lymph and Plasma Mapped by 2D‐DIGE and 1D SDS‐PAGE Coupled with NanoLC‐ESI‐MS/MS Bottom‐Up Proteomics

Abstract

In this study a global proteomic approach was used to define the protein content of matched samples of afferent prenodal lymph and plasma derived from healthy volunteers. The analysis was performed using two analytical methodologies coupled with nanoliquid chromatography‐tandem mass spectrometry (nanoLC Orbitrap‐ESI‐MS/MS): one‐dimensional gel electrophoresis (1DEF nanoLC Orbitrap‐ESI‐MS/MS), and two‐dimensional fluorescence difference‐in‐gel electrophoresis (2D‐DIGE nanoLC‐ESI‐MS/MS). The 253 significant identified proteins (p<0.05) obtained from the tandem mass spectrometry data were further analyzed with pathway analysis (IPA) to define the functional signature of prenodal lymph and matched plasma. The common proteome between the two biological fluids (144 out of 253 proteins) was dominated by complement activation and blood coagulation components, transporters and protease inhibitors. The enriched proteome of human lymph (72 proteins) consisted of products derived from the extracellular matrix, apoptosis and cellular catabolism. In contrast, the enriched proteome of human plasma (37 proteins) consisted of soluble molecules of the coagulation system and cell‐cell signaling factors. The functional networks associated with both common and source‐distinctive proteomes highlight the major biological activities of these immunologically relevant body fluids.