Identification of sero-diagnostic antigens for the early diagnosis of Johne's disease using MAP protein microarrays

Authors: LI, LINGLING - Pennsylvania State University; Bannantine, John; CAMPO, JOSEPH - Antigen Discovery, Inc; RANDALL, ARLO - Antigen Discovery, Inc; GROHN, YRJO - Cornell University; SCHILLING, MEGAN - Pennsylvania State University; KATANI, ROBAB - Pennsylvania State University; RADZIO-BASU, JESSICA - Pennsylvania State University; EASTERLING, LAUREL - Pennsylvania State University; KAPUR, VIVEK - Pennsylvania State University

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/7/2019
Publication Date: 11/26/2019
Citation: Li, L., Bannantine, J.P., Campo, J.J., Randall, A., Grohn, Y.T., Schilling, M., Katani, R., Radzio-Basu, J., Easterling, L., Kapur, V. 2019. Identification of sero-diagnostic antigens for the early diagnosis of Johne's disease using MAP protein microarrays. Scientific Reports. 9:17573. https://doi.org/10.1038/s41598-019-53973-x.
DOI: https://doi.org/10.1038/s41598-019-53973-x

Interpretive Summary: This paper represents a continuation of papers published in 2017 that examined new Mycobacterium avium subspecies paratuberculosis (MAP) antigens using the M. tuberculosis array as a screening tool (see Bannantine et al., 2017 Clinical Vaccine Immunology and Li et al. 2017 PLOS One). However, in this study, we used the Map protein array combined with our well-characterized serum set to identify antigens that are detected early in the disease process. We identified antigens that are strong at the early stages of Johne's disease and a set of antigens that are strong at later stages of Johne's disease. These findings will be used to build an assay for a Johne's disease diagnostic test. This information is important to animal producers, researchers and stakeholders.

Technical Abstract: Considerable effort has been directed toward controlling Johne’s disease (JD), a chronic granulomatous intestinal inflammatory disease caused by Mycobacterium avium subsp. paratuberculosis (MAP) in cattle and other ruminants. However, progress in controlling the spread of MAP infection has been impeded by the lack of reliable diagnostic tests that can identify animals early in the infection process and help break the transmission chain. To identify reliable antigens for early diagnosis of MAP infection, we constructed a MAP protein array with 868 purified recombinant MAP proteins, and screened a total of 180 well characterized serum samples from cows assigned to 4 groups based on previous serological and fecal test results: negative low exposure (NL, n=30); negative high exposure (NH, n=30); fecal positive, ELISA negative (F+E-, n=60); and both fecal and ELISA positive (F+E+, n=60). The analyses identified a total of 49 candidate antigens with reactivity compared with the NL group (p < 0.01), a majority of which have not been previously identified. While some of the antigens were identified as reactive in only one of the groups, others showed reactivity in multiple groups, including 28 in the NH, 26 in the F+E-, and 17 in the F+E+ groups. Using combinations of top reactive antigens in each group, the results reveal sensitivities of 60.0%, 73.3%, and 81.7% in the NH, F+E-, and F+E+, respectively at 90% specificity. Together, the results suggest that several of the novel candidate antigens identified in this study, particularly those that were reactive in the NH and F+E- groups, have potential utility for the early sero-diagnosis of MAP infection.