Anti-viral antibody profiling by high density protein arrays

Viral infections elicit antiviral antibodies and have been associated with various chronic dis-eases. Detection of these antibodies can facilitate diagnosis, treatment of infection, and un-derstanding of the mechanisms of virus-associated diseases. In this work, we assayed antiviralantibodies using a novel high-density nucleic acid programmable protein array (HD-NAPPA)platform. Individual viral proteins were expressed in situ directly from plasmids encodingproteins in an array of microscopic reaction chambers. Quality of protein display and serum re-sponse was assured by comparing intra- and inter-array correlation within or between printingbatches with average correlation coefficients of 0.91 and 0.96, respectively. HD-NAPPA showedhigher signal-to-background ratio compared with standard NAPPA on planar glass slides andELISA. Antibody responses to 761 antigens from 25 different viruses were profiled amongpatients with juvenile idiopathic arthritis and type 1 diabetes. Common and unique antibodyreactivity patterns were detected between patients and healthy controls. We believe HD-viral-NAPPA will enable the study of host–pathogen interactions at unprecedented dimensions andelucidate the role of pathogen infections in disease development.