Novel polyprotein antigens designed for improved serodiagnosis of bovine tuberculosis

Authors: LYASHCHENKO, KONSTANTIN - Chembio Diagnostic Systems, Inc; SIKAR-GANG, ALINA - Chembio Diagnostic Systems, Inc; SRIDHARA, ARCHANA - Chembio Diagnostic Systems, Inc; JOHNATHAN-LEE, ASHLEY - Chembio Diagnostic Systems, Inc; LAMBOTTE, PAUL - Chembio Diagnostic Systems, Inc; ESFANDIARI, JAVAN - Chembio Diagnostic Systems, Inc; IRETON, GREGORY - Infectious Diseases Research Institute; DUTHIE, MALCOLM - Infectious Diseases Research Institute; REED, STEVEN - Infectious Diseases Research Institute; JONES, GARETH - Animal And Plant Health Agency; VORDERMEIER, MARTIN - Animal And Plant Health Agency; THACKER, TYLER - Animal And Plant Health Inspection Service (APHIS); Palmer, Mitchell; WATERS, WADE - Retired ARS Employee

Submitted to: Frontiers in Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/28/2021
Publication Date: 8/28/2021
Citation: Lyashchenko, K.P., Sikar-Gang, A., Sridhara, A.A., Johnathan-Lee, A., Lambotte, P., Esfandiari, J., Ireton, G.C., Duthie, M., Reed, S.G., Jones, G., Vordermeier, M.H., Thacker, T.C., Palmer, M.V., Waters, W.R. 2021. Novel polyprotein antigens designed for improved serodiagnosis of bovine tuberculosis. Frontiers in Veterinary Science. 240. Article 110320. https://doi.org/10.1016/j.vetimm.2021.110320.
DOI: https://doi.org/10.1016/j.vetimm.2021.110320

Interpretive Summary: Bovine tuberculosis is a disease of both cattle and humans. Due to both public and animal health concerns, the USDA initiated a bovine tuberculosis eradication campaign in 1917, which remains in effect. Although great progress has been made, one obstacle to eradication has been the lack of rapid, accurate diagnostic tests. Current diagnostic tests require multiple animal handling events, are slow and not always accurate. In this study we evaluated various versions of a rapid test requiring a single blood sample and showed that one version identified infected animals with 84% accuracy. Use of such an assay, in combination with existing tests could expedite eradication.

Technical Abstract: Recent studies have demonstrated potential for serologic assays to improve surveillance and control programs for bovine tuberculosis. Due to the animal-to-animal variation of the individual antibody repertoires observed in bovine tuberculosis, it has been suggested that serodiagnostic sensitivity can be maximized by use of multi-antigen cocktails or genetically engineered polyproteins expressing immunodominant B cell epitopes. In the present study, we designed three novel multiepitope polyproteins named BID109, TBf1, and TBf2, with each construct representing a unique combination of four full-length peptides of Mycobacterium bovis predominantly recognized in bovine tuberculosis. Functional performance of the fusion antigens was validated using multi-antigen print immunoassay (MAPIA) and Dual Path Platform (DPP) technology with panels of monoclonal and polyclonal antibodies generated against individual proteins included in the fusion constructs as well as with serum samples from M. bovis-infected and non-infected cattle, American bison, and domestic pigs. It was shown that epitopes of each individual protein were expressed in the fusion antigens being accessible for efficient binding by the respective antibodies. The three fusion antigens demonstrated stronger immunoreactivity in MAPIA as compared to that of single proteins. Evaluation of the fusion antigens in DPP assay using serum samples from 125 M. bovis-infected and 57 non-infected cattle showed the best accuracy (~84percent) for TBf2 antigen composed of MPB70, MPB83, CFP10, and Rv2650c proteins of M. bovis. Thus, the study results suggest a potential for the multiepitope polyproteins to improve diagnostic sensitivity of serologic assays for bovine tuberculosis.