Advances and Applications of Antibody Arrays - Proteomic Profiling of Pancreatic Disease

Sammanfattning: Recombinant antibody microarrays have advanced into indispensable tools for large-scale, high-throughput multiplexed serum proteomics. This thesis, based upon five original papers, deals with the development of an in-house designed antibody microarray platform, and its applications for serum profiling of pancreatic disease. Pancreatic cancer is the 4th deadliest cancer, with a 5-year survival rate of only 6%. In order to increase the survival of this deadly disease, novel diagnostic biomarkers for earlier detection will be essential. In paper I and II of this thesis, we identified candidate biomarker signatures for predicting pancreatic cancer among healthy controls and pancreatitis. Pancreatitis (pancreatic inflammation) is symptomatically highly similar to pancreatic cancer, and biomarkers able to discriminate pancreatic cancer from pancreatitis would be of great clinical value. Pancreatitis appears in mainly chronic, acute, and autoimmune manifestations, and like for pancreatic cancer, there is a lack of high-performing biomarkers for diagnosis and stratification. In paper III, we applied antibody microarrays for pancreatitis protein profiling, and presented tentative biomarker signatures for the three main subtypes of this disease. In parallel to performing clinical applications of the antibody microarrays, technical efforts for improving and expanding the use of the platform have also been conducted. In paper IV, we studied the impact of the antibody-surface interplay, and evaluated different solid supports for antibody microarray production. We also took the first steps towards developing a user-friendly ELISA-like multiplexed biomarker assay, by presenting the first plate-based recombinant array-in-well set-up. In paper V, we designed protocols for an increased utility of the antibody microarray platform, to comprise not only targeting of proteins, but also serum/plasma profiling of glycan and carbonyl groups. Post-translational modification of proteins, like glycosylation and carbonylation (oxidation) is often altered in disease, and biomarkers based on differentiated levels of these modifications may complement traditional protein biomarkers. Proof-of-concept was demonstrated for preeclampsia, a common pregnancy disorder, for which the results indicated that particularly the level of carbonylation could be used for diagnosis and stratification. In conclusion, the work in this thesis has contributed to an improved and increased utility of the recombinant antibody microarray technology, and demonstrated its use for serum proteomic profiling of pancreatic disease.