Recombinant Foot-and-Mouth Disease (FMDV) nonstructural protein 3A fused to green fluorescent protein (GFP) as a candidate probe to identify FMDV infected cattle in serosurveys

LOTUFO, CECILIA; BERGMANN, INGRID; MATTION, NORA; WILDA, MAXIMILIANO; GRIGERA, PABLO

ARCHIVES OF VIROLOGY

SPRINGER WIEN

Lugar: Viena; Año: 2017 vol. 162 p. 2279 - 2286

0304-8608

Recombinant protein 3A-EGFP, a fusion construct between foot-and-mouthdisease virus (FMDV) non-structural protein 3A and the enhanced greenfluorescent protein (EGFP) was expressed in BL21-DE3 cells. The identity of thepartially purified protein 3A-EGFP was confirmed by its reactivity with sera fromcattle infected with FMDV and with a monoclonal antibody specific for FMDV-3ABC (MAb3H7) in Western blot assays. No reactivity was observed with serafrom non-infected vaccinated animals. The performance of 3A-EGFP as anantigen in an indirect ELISA assay (3A-EGFP ELISA) was assessed andcompared with that of the previously developed and validated capture ELISAwhich uses a 3ABC recombinant antigen (3ABC ELISA) that was widely appliedfor serological surveys in Argentina. Parallel analysis of strong and weak positivereference sera from infected animals and 329 serum samples from non-infectedvaccinated cattle showed that the 3A-EGFP antigen unequivocally identifies serafrom FMDV infected cattle with similar performance to its 3ABC counterpart.The 3A-EGFP ELISA is simpler and faster to perform than the 3ABC ELISA,since it does not require a capture step with a specific antibody. Moreover, theexpression and storage of the recombinant 3A-EGFP is simplified by the absenceof residual autoproteolytic activity associated to the 3C sequence.We conclude that the 3A-EGFP ELISA constitutes a promising screening methodin serosurveys to confirm either presence or absence of FMDV infected animals.