Expression of a secreted version of the Hemagglutinin-neuraminidase glycoprotein of Newcastle disease virus: its evaluation as a diagnostic reagent.

SILVINA CHIMENO ZOTH; JUAN MANUEL CARBALLEDA; EVANGELINA GOMEZ; ELISA CARRILLO; ANALIA BERINSTEIN

JOURNAL OF VETERINARY DIAGNOSTIC INVESTIGATION

AMER ASSOC VETERINARY LABORATORY DIAGNOSTICIANS INC

Año: 2011 vol. 23

1040-6387

The haemaglutinin-neuraminidase glycoprotein of Newcastle disease virus constitutes, together with the fusion glycoprotein, the main surface antigen of this avian pathogen which causes a highly contagious disease, relevant economically worldwide. The purpose of this work was to obtain the haemaglutinin-neuraminidase glycoprotein as a soluble antigen in culture supernatants of recombinant baculovirus-infected Sf9 cells and to evaluate its application to the development of a recombinant Enzyme-linked immunosorbent assay for the analysis of chicken sera. A transfer vector for baculovirus containing the sequence of a mellitin signal peptide was constructed and the sequence coding for haemaglutinin-neuraminidase protein without its own signal peptide was cloned. The recombinant protein was secreted and recovered easily from the culture medium of Sf9 infected cells. The recombinant protein was evaluated as antigen for Enzyme-linked immunosorbent assay, coating the plates with the recovered haemaglutinin-neuraminidase diluted in carbonate buffer. The developed assay revealed high sensitivity (91.14 %) and specificity (99.3 %) when compared to the hemagglutination-inhibition test. The results presented in this work show that the strategy designed allowed not only to obtain the protein of interest free in the cell culture supernatant but also to prove that the protein retains its antigenic properties. This method constitutes a very useful tool as a diagnostic reagent capable of detecting the presence of anti- haemaglutinin-neuraminidase antibodies very efficiently in chicken sera.