Acta Vet. Brno 2017, 86: 11-17
Expression and diagnostic use of recombinant M protein of the porcine reproductive and respiratory syndrome virus
Matrix M protein combined with nucleocapsid N protein could be a promising combination of virus antigens for diagnosing the porcine reproductive and respiratory syndrome. The goal of this work was to express the recombinant M protein of the porcine reproductive and respiratory syndrome virus in Escherichia coli cells and compare its serological reactivity with the N protein of the virus. The gene coding for the M protein was cloned into the pDest17 vector. The resulting protein was purified by metalochelating affinity chromatography. Recombinant M protein was applied as an antigen in immunoblot test and compared on a panel of porcine sera with N protein based IDEXX test. Of 120 examined samples, the majority (78.3%) gave identical results using both compared tests. From the group of discrepant results, IDEXX test identified considerably more positive sera (17.5%) than M protein based test (4.2%). The main contribution of the work is finding that although IDEXX test proved to be more sensitive than M protein based test, 4.2% of sera would escape detection by serological test based on N protein. Further development and purification of the M protein for the use in Enzyme Linked Immunosorbent Assay format test could increase the performance of serological testing.
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Funding
This work was supported by the Grant Agency of the Ministry of Education, Youth and Sports of the Czech Republic, COST grant no. LD12001; Internal Grant Agency of VFU Brno No. 107/2015/FVL; and by project QJ1210120 funded by National Agency for Agricultural Research (NAZV).
