Cloning and expression of fragment of the rabies virus nucleoprotein gene in Escherichia coli and evaluation of antigenicity of the expression product

ABSTRACT

Rabies virus nucleoprotein [N protein] encapsidates genomic RNA of the virus and forms the viral ribonucleoprotein complex. These N proteins represent highly organized structures which activate proliferation of B cells and production antibodies against the N protein. In addition to the B cell, the rabies virus N protein has been shown to induce potent T helper cell responses resulting in a long-lasting and strong humoral immune response. Rabies virus N protein is a molecular target of choice for development of tools to diagnose acute rabies infection. We produced a recombinant immune reactive C-terminal fragment of the rabies virus N protein which contains an antigenic determinant located between positions 360-389. Synthetic gene encoding the N protein was cloned into an expression plasmid to produce the recombinant antigen in Escherichia coli cells BL21 [DE3]. SDS-PAGE showed presence of the product with expected molecular weight [44 kDa]. The recombinant fragment of the N protein efficiently recognized antibodies in sera from mice immunized with an inactivated rabies virus. Thus produced recombinant antigen of the rabies virus N protein can be used in an enzyme-linked immunosorbent assay [ELISA] for diagnosis of the rabies infection