Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement
Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.
Identification of KIAA Proteins in Immune Complex Proteome from Juvenile Idiopathic Arthritis and Systemic Lupus Erythematosus.
Chauhan2, Anil, Gilliam2, Brooke, Riley1, Catherine P., Adamec1, Jiri, Moore3, Terry L.
Biomarkers discovered by proteome analysis are not only useful for patient stratification but for monitoring therapeutic responses and understanding of disease pathogenesis. Biological fluids such as plasma although a good source of information, present a technical challenge due to at least ten orders of magnitude dynamic range of protein concentration. Protein and peptide immuno-affinity pre-fractionation coupled with mass spectometry (MS)-based proteomics have been used for biomarker discovery; however a prior knowledge of the disease association is required. Thus we wanted to develop a proteomic approach that is capable of identifying low abundance disease associated proteins as a possible biomarker candidate. We achieved this by combining receptor affinity for isolation of immune complexes (ICs) with downstream coupling to nano-LC/MS-MS.
Fifteen IC samples from juvenile idiopathic arthritis (JIA) and systemic lupus erythematosus (SLE) patients were purified using receptor affinity columns and then fractionated on a Criterion XT Bis Tris precast 420% polyacryamide gel. Thereafter, each sample protein lane was cut into 5 equal pieces. Tryptic peptides from these samples were then developed on a nanoLC-Chip system (1100 Series LC, Agilent) and separated on the on-chip C-18 reversed phase ZORBAX 300SB-C18 (0.075mm × 150 mm; Agilent). The NanoLC-MS chromatograms were acquired in positive ion mode with a capillary voltage of 1850 V, an end plate offset of 500 V, dry gas at 300°C and 4 L/min. Spectra were acquired for 3502000 m/z at a scan speed of 8,100 m/z/s with 0.15 s maximum accumulation time.
We identified a total of 873 proteins from ICs purified from the fifteen samples. The ICs from the JIA patients showed more proteins associated with cell adhesion, proliferation, protein transport, and ATP biosynthetic process, while the SLE group with cytoskeleton organization, signal transduction, T cell activation, and intracellular and signaling cascade. A number of proteins that are known target of post translational modifications in autoimmune response were also identified. The common proteins present in these ICs were complement proteins, fibrinogen, apolipoprotein A-I, cartilage acidic protein, and S100 calcium-binding proteins. The SLE-ICs showed a large number of nuclear proteins such as zinc finger proteins including 652, 644, 133, and matrin type 5. In addition, ICs from JIA and SLE showed the presence of T cell receptor beta chains, suggesting an active role for T cells. KIAA proteins are proteins encoded by large cDNA identified by Kazusa cDNA project. They display multiple domains that suggset their involvement in interactions with other biological molecules. We observed two unique sets of KIAA proteins one associated to JIA and other with SLE. There are 2031 KIAA cDNA entries in HUGE database that are being characterized (http://www.jp/huge/ppi).
We show a successful approach to identify low abundance antigens from ICs.The IC proteome shows more proteins unique to individuals rather than disease group. The presence of KIAA proteins in the ICs suggest their role in disease pathogenesis and as a new potential biomarker group.
To cite this abstract, please use the following information:
Chauhan, Anil, Gilliam, Brooke, Riley, Catherine P., Adamec, Jiri, Moore, Terry L.; Identification of KIAA Proteins in Immune Complex Proteome from Juvenile Idiopathic Arthritis and Systemic Lupus Erythematosus. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :1601