GLYCOPROTEIN G RABIES VIRUS EXPRESSION IN INSECT CELLS FOR DIAGNOSTIC PURPOSE IN VACCINATED LLAMAS

ALEXANDRA TARGOVNIK; MC CALLUM GREGORIO; SMITH, IGNACIO; ARREGUI, MARIANA BERNADETT; MATIAS MICUCCI; OSCAR PEREZ; GARIELA LOPEZ; VICTORIA ALFONSO; ALEJANDRO NUSBLAT; M.V. MIRANDA

CABA

Congreso; XXIX International Conference on Rabies in the Americas; 2018

Rabies is one of the principal zoonosis with worldwide distribution. The disease in llamas produces great economic losses in the productive system. The prevention against rabies virus (RABV) infection is done through vaccination with the inactivated virus. The level of protection can be assessed bydetermining the titre of neutralizing serum antibodies induced by RABV glycoprotein (RABV-G) in vaccinated individuals, which can be measured using an enzyme-linked immunosorbent assay. The aim of this work is to optimize a process for the production of the RABV-G ectodomain in Sf9 cell.The recombinant baculovirus was constructed by introducing the sequence corresponding to the ectodomain region of RABV-G, under the polyhedrin promoter, fused to the viral signal peptide GP67 at its amino terminus and a 6-histidine tag at its carboxyl terminus. Despite the inefficient secretionof the RABV-G, it was possible to recover it from the cell lysate. Insect cells infected at multiplicity of infection of 0.5 at day 3 expressed 7 mg litre-1. The recombinant RABV-G had a molecular mass of approximately 50 kDa according to SDS-PAGE analysis. PGnase F and Tunicamycin treatment confirmed that the protein is glycosilated. RABV-G was identified by LC-MS and was purified by metalion affinity chromatography directly from the cell extract with a yield of 99% and a purity of 67%.Purified RABV-G was succesfully used to detect specific antibodies in serum samples derived from rabies-vaccinated llamas. These results indicate that the recombinant RABV-G can be used as an antigen in the development of diagnostic kits.